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HomeMy WebLinkAboutNCD003162542_Badin Business Park_Corrective Action_20230511Badin Business Park LLC c/o Alcoa Corporation 201 Isabella Street Suite 500 Pittsburgh, PA 15212-5858 USA Tel: 1 412 315 2900 May 11, 2023 Robert C. McDaniel Facility Management Branch Hazardous Waste Section North Carolina Department of Environmental Quality 217 West Jones Street Raleigh, North Carolina 27603 Re: Badin Business Park Groundwater Sampling Plan Badin, North Carolina EPA ID: NCD 003 162 542 Dear Mr. McDaniel: Please find enclosed with this letter the Groundwater Sampling Plan, dated May 2023. This Sampling Plan has been prepared as a guidance document presenting the rationale and procedures for groundwater data collection in support of potential refinements to the Facility hydrogeological conceptual site model (HCSM). This work is being pursued voluntarily and this Plan is being submitted for notification to the Department. Badin Business Park intends to commence the initial sampling event within the next 30 days. Should you have any questions or comments please contact Jason Mibroda of Alcoa at (412) 315- 2783 at your convenience. Respectfully, Ronald M. Morosky Director, Corporate Remediation and Technology Enc. cc: Jason Mibroda, Alcoa GROUNDWATER SAMPLING PLAN BADIN BUSINESS PARK FACILITY HIGHWAY 740 BADIN, NORTH CAROLINA PREPARED FOR: BADIN BUSINESS PARK LLC 201 ISABELLA STREET, PITTSBURGH, PA 15212 PREPARED BY: CIVIL & ENVIRONMENTAL CONSULTANTS, INC. 2704 CHEROKEE FARM WAY, SUITE 101 KNOXVILLE, TENNESSEE 37920 PHONE: (865) 977–9997 CEC PROJECT 300–226 MAY 2023 -i- Groundwater Sampling Plan - BBP May 2023 TABLE OF CONTENTS 1.0 INTRODUCTION..............................................................................................................1 1.1 Site History ............................................................................................................. 1 1.2 Data Review ............................................................................................................ 2 1.3 Plan Objectives ....................................................................................................... 3 2.0 SAMPLE LOCATION AND FREQUENCY ..................................................................4 2.1 Main Plant - Northwest Valley ............................................................................... 4 2.1.1 Sample Locations .........................................................................................5 2.1.2 Sample Quantities ........................................................................................6 2.2 Main Plant - West Fill Area .................................................................................... 7 2.2.1 Sample Locations .........................................................................................7 2.2.2 Sample Quantities ........................................................................................8 2.3 Main Plant - Central and Southern Portion ............................................................. 9 2.3.1 Sample Locations .........................................................................................9 2.3.2 Sample Quantities ......................................................................................10 2.4 Alcoa-Badin Landfill ............................................................................................ 11 2.4.1 Sample Location and Frequency ................................................................12 2.4.2 Sample Quantities ......................................................................................14 2.5 Old Brick Landfill ................................................................................................. 15 2.5.1 Sample Locations .......................................................................................15 2.5.2 Sample Quantities ......................................................................................16 2.6 Groundwater Level Gauging................................................................................. 17 3.0 SAMPLE DESIGNATION .............................................................................................18 3.1 Project Code .......................................................................................................... 18 3.2 Location Identifier Code ....................................................................................... 18 3.3 Sequential Sample Number................................................................................... 19 4.0 SAMPLE EQUIPMENT AND PROCEDURES ...........................................................20 4.1 Quality Assurance Sampling................................................................................. 21 4.2 Standard Operating Procedures............................................................................. 22 5.0 SAMPLE HANDLING AND ANALYSIS .....................................................................24 6.0 SCHEDULE AND REPORTING ...................................................................................26 FIGURES Figure 1………………………………………………………………………... Site Location Map Figure 2……………………………………………………………….Wells in Sampling Program Figure 3……………………………………………………………......Wells in Gauging Program -ii- Groundwater Sampling Plan - BBP May 2023 TABLES Table 1: Northwest Valley Area Sample Locations ....................................................................... 5 Table 2: Northwest Valley Area Event 1 Analyte List ................................................................... 5 Table 3: Northwest Valley Area Sample Quantities ....................................................................... 6 Table 4: West Fill Area Sample Locations ..................................................................................... 7 Table 5: West Fill Area Event 1 Analyte List ................................................................................. 8 Table 6: West Fill Area Sample Quantities .................................................................................... 8 Table 7: Central and Southern Portion Sample Locations ............................................................. 9 Table 8: Central and Southern Portion Event 1 Analyte List ....................................................... 10 Table 9: Central and Southern Portion Sample Quantities ........................................................... 10 Table 10: Alcoa-Badin Landfill Sample Locations and Frequency.............................................. 12 Table 11: Alcoa-Badin Landfill Event 1 Analyte List .................................................................. 12 Table 12: Alcoa-Badin Landfill Event 2 Analyte List .................................................................. 13 Table 13: Alcoa-Badin Landfill Sample Quantities per Event ..................................................... 14 Table 14: Old Brick Landfill Sample Locations ........................................................................... 16 Table 15: Old Brick Landfill Event 1 Analyte List ...................................................................... 16 Table 16: Old Brick Landfill Sample Quantities .......................................................................... 16 Table 17: Water Level Gauging Locations ................................................................................... 17 Table 18: Sample Containers, Preservation, and Hold Times ...................................................... 24 Table 19: Tentative Schedule ........................................................................................................ 26 APPENDICES Appendix A ……………………………………...Groundwater Elevation Monitoring Procedures Appendix B …………………………………………………...Groundwater Sampling Procedures Appendix C …….Field Instrumentation, Calibration, and Operation and Maintenance Procedures Appendix D…………………………………………….. Equipment Decontamination Procedures Appendix E ……………………………...Sample Handling, Packaging, and Shipping Procedures Appendix F ………………………………………………………………….Example Field Forms -1 - Groundwater Sampling Plan - BBP May 2023 1.0 INTRODUCTION On behalf of Badin Business Park LLC (BBP), Civil & Environmental Consultants, Inc. (CEC) has prepared this Groundwater Sampling Plan (GWSP) for the BBP facility (Facility), located at 293 NC 740, Badin, North Carolina 28009 (Figure 1). This GWSP has been prepared as a guidance document presenting the rationale and procedures for groundwater data collection in support of potential refinements to the Facility hydrogeological conceptual site model (HCSM). The approach for the sampling was developed based on information obtained during historical investigations and is intended to supplement previous investigations at the Facility. 1.1 SITE HISTORY The Facility, formerly known as the Alcoa-Badin Works facility, previously contained a primary aluminum smelting plant (Main Plant). Aluminum production began at the Main Plant in 1916 after purchasing and completing the holdings of a French combine, which had begun work on a smelter. The Main Plant consisted of potlines; electrode plants where anodes and cathodes were manufactured; casting facilities; a machine shop; and various offices and utility buildings. Aluminum production was curtailed in August 2002. The Main Plant continued to manufacture anodes and high-purity aluminum until 2007. The Main Plant was permanently closed in 2010. Since then, the former Main Plant has been redeveloped into a business park for manufacturing companies. On March 30, 1992, the Facility was issued a Hazardous Waste Management Permit to store spent potlining. The Hazardous Waste Management Permit required the identification and investigation of solid waste management units (SWMU) and areas of concern (AOC) for potential adverse impact to environmental media at the Facility. A total of forty-nine SWMUs and AOCs have been identified at the Facility. The Resource conservation and Recovery Act (RCRA) Facility Assessment (RFA) Report includes information for SWMU Nos. 1 through 34 and AOCs A and B. Information for SWMU Nos. 35 through 47 was provided in subsequent correspondence to the Agency. As part of the RFA and subsequent processes, no further action (NFA) was immediately determined for twenty-two SWMUs, -2 - Groundwater Sampling Plan - BBP May 2023 Confirmatory Sampling (CS) was conducted at five units in which no further investigation (NFI) was warranted, NFI was determined for two units, eighteen units were investigated further under the RCRA Facility Investigation process, and two storage units were to be permitted. The results of the extensive investigation were evaluated and summarized in the March 1990 RFA Report, June 1993 Confirmatory Sampling Report, and March 2001 RCRA Facility Investigation (RFI) Report. The RFI Report was approved by NCDENR on December 19, 2007. With the approval of the RFI Report, the Corrective Measures Study (CMS) process was initiated to identify and evaluate remedial alternatives for the identified contaminated media. Phase 4 of the CMS identified and evaluated the alternatives for corrective action and Phase 5 of the CMS provided the justification and recommendation of the selected alternatives for the remedy of the Facility. Both reports are currently under review by NCDEQ. As a result of the investigations, interim measures (IM), and remedial actions conducted, NFA or NFI has been granted for all or a portion of forty-three SWMUs. The two permitted storage units were cleaned closed. A portion of nine SWMUs including the groundwater at the Main Plant Area, groundwater at the Alcoa-Badin Landfill, and groundwater at the Old Brick Landfill were carried forward to the CMS. 1.2 DATA REVIEW Multiple investigations and remedial efforts have been performed at the Facility. Since the submittal of the March 1990 Interim RCRA Facility Assessment Report, over 200 documents have been submitted to the State of North Carolina under different regulatory programs. Primary sources reviewed for the purposes of developing this sampling strategy included but are not limited to:  Confirmatory Sampling Report as prepared by Law Environmental, Inc. (Law) and dated June 28, 1993;  Addendum to the Confirmatory Sampling Report as prepared by Law and dated November 1, 1993;  RCRA Facility Investigation Report, Alcoa Badin Works, Badin, North Carolina, as prepared by MFG, Inc. and dated March 2001; -3 - Groundwater Sampling Plan - BBP May 2023  Phase 3 Engineering Data Collection for the Corrective Measures Study Report (Phase 3 Report) as prepared by ENVIRONEERING, Inc. and dated October 31, 2012; and,  Hydrogeological Conceptual Site Model Update (HCSM Update Report) as prepared by EHS Support LLC and dated December 2022. The HCSM Update Report was accepted by the NCDEQ in a letter dated March 9, 2023. The HCSM identified that partially weathered rock and fractured rock are contiguous across the Facility and are the primary Main Plant-wide hydrogeologic units where groundwater advection occurs. Sources of recharge to groundwater in the partially weathered rock and fractured rock include precipitation infiltration and recharge from Badin Lake. Furthermore, historical analytical data suggest that mixing between recharge water and groundwater may provide conditions where natural, geochemical attenuation of fluoride can occur. 1.3 PLAN OBJECTIVES Since performance of the last Facility-wide groundwater sampling event, portions of the Main Plant were demolished and redeveloped into a business park. This redevelopment, coupled with natural attenuation processes, have the potential to affect groundwater conditions. A comprehensive groundwater sampling event is proposed to update the understanding of groundwater conditions. The updated groundwater conditions may be used as a basis for verifying the findings of the HCSM Update Report. This GWSP is intended to meet the above objectives by planning sample collection and analytical activities in accordance with acceptable protocols. The information presented in this GWSP will enable field personnel to collect field samples and measurements in a manner that meet the project objectives. -4 - Groundwater Sampling Plan - BBP May 2023 2.0 SAMPLE LOCATION AND FREQUENCY The groundwater well network at the Facility includes 126 monitoring wells and piezometers located at the former Main Plant and several adjacent offsite locations. In accordance with the CMS, the network is divided into separate areas including:  The Main Plant, including o The Northwest Valley Area; o The West Fill Area; and o The Central and Southern Portion;  The Alcoa-Badin Landfill; and  The Old Brick Landfill. Samples will be collected at the locations and frequency detailed in the sections below. Locations were selected based the ability to collect spatially distributed data from targeted hydrogeologic units. Primary analytical parameters were selected for the purposes of updating historical constituent distribution and variability. Supplemental analytical data will be used to evaluate hydrogeologic communication between subsurface hydrogeologic units and surface water bodies with the intent of refining the HCSM. The first sampling event will be comprehensive and encompass approximately 76 of the Facility wells (Figure 2) and include collection of additional geochemical data. The second sampling event will be supplemental and include four of the Facility wells. Groundwater level measurements will be collected from select wells (Figure 3) prior to purging. 2.1 MAIN PLANT - NORTHWEST VALLEY The northern portion of the Main Plant is underlain by a natural west-east trending valley (Northwest Valley) that was progressively filled during the period between 1916 and 1968. SWMU No. 1, the On-Site Landfill, is located at the western end of the Northwest Valley. From the 1930s to the 1970s, the Facility periodically placed fill materials, including Facility process materials, in SWMU No. 1. SWMU No. 44, the Pine Tree Grove, is located at the eastern end of the valley. Between 1959 and 1961, this former cove of Badin Lake was filled with natural soils and anthropogenic materials to the current grade. -5 - Groundwater Sampling Plan - BBP May 2023 2.1.1 Sample Locations Table 1 presents a summary of the planned sample locations for the Northwest Valley Area of the Main Plant. Table 1: Northwest Valley Area Sample Locations Wells for Event 1 MW-2 MW-6 MW-12 MW-20 MW-25A MW-200 MW-2A MW-6A MW-13 MW-20A MW-27 MW-201 MW-3 MW-8 MW-16 MW-21 MW-110 MW-202 MW-4 MW-9 MW-18 MW-23 MW-111 MW-217 MW-5 MW-11 MW-19 MW-25 MW-112 Table 2 presents the analyte list for each well for the Northwest Valley Area. Table 2: Northwest Valley Area Event 1 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2320B 6010D/ 6020B 5310B 2540D 8260D FS MW-2 X X - - - - - - - - X MW-2A X X X X X X X X X - X MW-3 X X - - - - - - - - X MW-4 X X X X X X X X X X X MW-5 X X - - - - - - - - X MW-6 X X X X X X X X X - X MW-6A X X X X X X X X X - X MW-8 X X X X X X X X X X X MW-9 X X - - - - - - - X X MW-11 X X X X X X X X X - X MW-12 X X - - - - - - - - X MW-13 X X X X X X X X X - X MW-16 X X X X X X X X X X X MW-18 X X - - - - - - - - X MW-19 X X - - - - - - - - X MW-20 X X - - - - - - - - X MW-20A X X - - - - - - - - X MW-21 X X - - - - - - - - X MW-23 X X X X X X X X X - X MW-25 X X X X X X X X X - X MW-25A X X X X X X X X X - X MW-27 X X X X X X X X X - X -6 - Groundwater Sampling Plan - BBP May 2023 Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2320B 6010D/ 6020B 5310B 2540D 8260D FS MW-110 X X X X X X X X X X X MW-111 X X X X X X X X X - X MW-112 X X X X X X X X X - X MW-200 X X - - - - - - - X X MW-201 X X X X X X X X X - X MW-202 X X - X MW-217 X X X X X X X X X - X Total 29 29 17 17 17 17 17 17 17 6 29 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids 8260D = Volatile Organic Compounds FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.1.2 Sample Quantities Table 3 presents a summary of the sample quantities for the Northwest Valley Area. Table 3: Northwest Valley Area Sample Quantities Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater 1677 29 3 2 5 2 0 41 Groundwater 9056Aa/4500F 29 3 2 5 2 0 41 Groundwater 9056Ab 17 3 2 5 2 0 29 Groundwater 353.2 17 3 2 5 2 0 29 Groundwater 4500P 17 3 2 5 2 0 29 Groundwater 2320B 17 3 2 5 2 0 29 Groundwater 6010D/6020B 17 3 2 5 2 0 29 Groundwater 5310B 17 3 2 5 2 0 29 Groundwater 2540D 17 3 2 5 2 0 29 Groundwater 8260D 6 1 1 2 2 1 13 Groundwater FS 29 0 0 0 0 0 29 Notes: 1 One duplicate sample is to be collected per 10 primary field samples. 2 Matrix spike, matrix spike duplicate, and equipment blank samples are to be collected 1 per 20 primary field samples. 3 Field blank samples are to be collected each day of sampling; number is based on anticipated days required to complete sample collection. 4 Trip blank samples are required for each cooler containing 8260D (VOC) samples; number is based on anticipated number of coolers. 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate -7 - Groundwater Sampling Plan - BBP May 2023 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids 8260D = Volatile Organic Compounds FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.2 MAIN PLANT - WEST FILL AREA South of the Northwest Valley, a second west-east trending valley (West Fill Area) was progressively filled during the period between 1916 and 1968. This valley is referred to as the “West Fill Area” and includes two identified SWMUs – SWMU No. 43, the Overhead Crane Rebuild Structure, and SWMU No. 46, the Coke Management Area, formerly known as the West SPL Area. SWMU No. 43 was an open structure consisting of a concrete slab and a sloping metal roof supported by steel columns. The structure contained several girders for placing and positioning overhead cranes. The structure was dismantled in February 1994 leaving only the concrete slab. SWMU No. 46 directly overlies SWMU No. 43. As detailed in the Phase 3 Report, a review of historical topographic maps, historical photographs, aerial imagery, and investigative activities confirmed that SWMU No. 46 is a fill area related to Main Plant expansion and modernization activities. This data supported a morphology consisting of native fill soils and minor amounts of Main Plant process material remnants used to raise the area to its existing grade, or approximately 10 to 20 feet. 2.2.1 Sample Locations Table 4 presents a summary of the planned sample locations for the West Fill Area of the Main Plant. Table 4: West Fill Area Sample Locations Wells for Event 1 MW-1 MW-33 MW-37 MW-46 MW-29 MW-35 MW-45 MW-218 MW-32 -8 - Groundwater Sampling Plan - BBP May 2023 Table 5 presents the analyte list for each well for the West Fill Area of the Main Plant. Table 5: West Fill Area Event 1 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2320B 6010D/ 6020B 5310B 2540D FS MW-1 X X - - - - - - - X MW-29 X X X X X X X X X X MW-32 X X X X X X X X X X MW-33 X X - - - - - - - X MW-35 X X - - - - - - - X MW-37 X X X X X X X X X X MW-45 X X - - - - - - - X MW-46 X X X X X X X X X X MW-218 X X X X X X X X X X Total 9 9 5 5 5 5 5 5 5 9 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.2.2 Sample Quantities Table 6 presents a summary of the sample quantities for the West Fill Area of the Main Plant. Table 6: West Fill Area Sample Quantities Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater 1677 9 1 1 2 1 0 14 Groundwater 9056Aa/4500F 9 1 1 2 1 0 14 Groundwater 9056Ab 5 1 1 2 1 0 10 Groundwater 353.2 5 1 1 2 1 0 10 Groundwater 4500P 5 1 1 2 1 0 10 Groundwater 2320B 5 1 1 2 1 0 10 Groundwater 6010D/6020B 5 1 1 2 1 0 10 Groundwater 5310B 5 1 1 2 1 0 10 Groundwater 2540D 5 1 1 2 1 0 10 -9 - Groundwater Sampling Plan - BBP May 2023 Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater FS 9 0 0 0 0 0 9 Notes: 1 One duplicate sample is to be collected per 10 primary field samples. 2 Matrix spike, matrix spike duplicate, and equipment blank samples are to be collected 1 per 20 primary field samples. 3 Field blank samples are to be collected each day of sampling; number is based on anticipated days required to complete sample collection. 4 Trip blank samples are required for each cooler containing 8260D (VOC) samples; number is based on anticipated number of coolers. 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.3 MAIN PLANT - CENTRAL AND SOUTHERN PORTION The central and southern portion of the Main Plant formed as areas of engineered cut and fill during Main Plant construction and redevelopment. As presented in the HCSM Update Report, residual soils and saprolite were removed from the underlying partially weathered rock over a large portion of this area. Where residual soil and saprolite were largely removed, the dominant control on the groundwater flow direction is geologic structures within the partially weathered rock. The orientation of bedding and fractures affects groundwater flow direction and constituent fate and transport. Due to the effects of geologic structures, the presence of Badin Lake, and potential effects of Main Plant infrastructure, the primary groundwater flow direction at the Main Plant is believed to be directed away from Badin Lake trending to the south. 2.3.1 Sample Locations Table 7 presents a summary of the planned sample locations for the Central and Southern Portion of the Main Plant. Table 7: Central and Southern Portion Sample Locations Wells for Event 1 MW-10 BF-1 BF-8 MW-203 MW-208 MW-210 MW-14 BF-2 MW-103 MW-204 MW-209 MW-220 MW-15 BF-5 MW-104 MW-205 -10 - Groundwater Sampling Plan - BBP May 2023 Table 8 presents the analyte list for each well for the Central and Southern Portion of the Main Plant. Table 8: Central and Southern Portion Event 1 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2320B 6010D/6020B 5310B 2540D FS MW-10 X X - - - - - - - X MW-14 X X - - - - - - - X MW-15 X X - - - - - - - X BF-1 X X - - - - - - - X BF-2 X X - - - - - - - X BF-5 X X - - - - - - - X BF-8 X X X X X X X X X X MW-103 X X - - - - - - - X MW-104 X X X X X X X X X X MW-203 X X X X X X X X X X MW-204 X X X X X X X X X X MW-205 X X X X X X X X X X MW-208 X X - - - - - - - X MW-209 X X - - - - - - - X MW-210 X X - - - - - - - X MW-220 X X X X X X X X X X Total 16 16 6 6 6 6 6 6 6 16 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.3.2 Sample Quantities Table 9 presents a summary of the sample quantities for the Central and Southern Portion of the Main Plant. Table 9: Central and Southern Portion Sample Quantities Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater 1677 16 2 1 4 1 0 24 Groundwater 9056Aa/4500F 16 2 1 4 1 0 24 -11 - Groundwater Sampling Plan - BBP May 2023 Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater 9056Ab 6 1 1 1 1 0 10 Groundwater 353.2 6 1 1 1 1 0 10 Groundwater 4500P 6 1 1 1 1 0 10 Groundwater 2320B 6 1 1 1 1 0 10 Groundwater 6010D/6020B 6 1 1 1 1 0 10 Groundwater 5310B 6 1 1 1 1 0 10 Groundwater 2540D 6 1 1 1 1 0 10 Groundwater FS 16 0 0 0 0 0 16 Notes: 1 One duplicate sample is to be collected per 10 primary field samples. 2 Matrix spike, matrix spike duplicate, and equipment blank samples are to be collected 1 per 20 primary field samples. 3 Field blank samples are to be collected each day of sampling; number is based on anticipated days required to complete sample collection. 4 Trip blank samples are required for each cooler containing 8260D (VOC) samples; number is based on anticipated number of coolers. 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.4 ALCOA-BADIN LANDFILL SWMU No. 2, Alcoa-Badin Landfill, is a municipal/industrial solid-waste landfill located approximately 500 feet south of the Main Plant. It spans approximately 14 acres and prior to the placement of waste, this area contained a natural ravine. Municipal refuse from the town of Badin as well as Main Plant process materials and native fill material were placed in the ravine until operations at the Alcoa-Badin Landfill ceased in the mid-1970s. After operations ceased, the Alcoa-Badin Landfill was graded, covered with native soils, and seeded with grass. Interim measures, including re-grading and cover improvements, were completed in 1997. A seep collection system was voluntarily installed near the toe of the landfill in 2000 and subsequently upgraded with a trench collection and slurry barrier wall system in 2016. In 2017, the N.C. Department of Environmental Quality determined that further evaluation of the Alcoa-Badin Landfill was warranted. A Baseline Ecological Risk Assessment is currently in progress at the Alcoa-Badin Landfill. -12 - Groundwater Sampling Plan - BBP May 2023 2.4.1 Sample Location and Frequency Table 10 presents a summary of the planned sample locations and frequency for the Alcoa-Badin Landfill. Table 10: Alcoa-Badin Landfill Sample Locations and Frequency Well Event 1 Event 2 PZ-15 X - PZ-17 X - PZ-19 X - ABL-MW-1 X - ABL-MW-3 X X ABL-MW-4 X X ABL-MW-5 X X ABL-MW-6 X - ABL-PZ-2S X - ABL-PZ-2D X - ABL-PZ-3S X X PZ-18RD X - MW-215 X - MW-216 X - MW-211 X - MW-212 X - Table 11 and Table 12 present the analyte list for each well for the Alcoa-Badin Landfill by sampling event. Table 11: Alcoa-Badin Landfill Event 1 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2340B/ 6020B 6020B/ 7470A 6010D/ 6020B 2320 B 4500 H+ B 5310B/ 2540D D7511 8270E 1668A FS PZ-15 X X - - - - - - - - - - - - X PZ-17 X X X X X - - X X - - - - - X PZ-19 X X - - - - - - - - - - - - X ABL-MW-1 X X X X X - - X X - - - - - X ABL-MW-3 X X X X X X X - X X X X X X X ABL-MW-4 X X X X X X X - X X X X X X X ABL-MW-5 X X X X X X X X X X X X X X X ABL-MW-6 X X - - - - - - - - - - - - X ABL-PZ-2S X X - - - - - - - - - - - - X ABL-PZ-2D X X - - - - - - - - - - - - X ABL-PZ-3S X X X X X X X X X X X X X X X PZ-18RD X X X X X - - X X - - - - - X MW-211 X X X X X - - X X - - - - - X MW-212 X X X X X - - X X - - - - - X MW-215 X X - - - - - - - - - - - - X MW-216 X X X X X - - X X - - - - - X Total 16 16 10 10 10 4 4 8 10 4 4 4 4 4 16 -13 - Groundwater Sampling Plan - BBP May 2023 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2340B/6020B = Total Hardness (as CaCO3) by calculation; Calcium and Magnesium 6020B/7470A = Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, Silver, Mercury (Total and Filtered) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 4500 H+ B = pH 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids D7511 = Total Cyanide via ASTM 8270E = Polycyclic Aromatic Hydrocarbons 1668A = Polychlorinated Biphenyls (Congeners) FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) Table 12: Alcoa-Badin Landfill Event 2 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2340B/ 6020B 6020B/ 7470A 6010D/ 6020B 2320B 4500 H+ B 5310B/ 2540D D7511 8270E 1668A FS PZ-15 - - - - - - - - - - - - - - - PZ-17 - - - - - - - - - - - - - - - PZ-19 - - - - - - - - - - - - - - - ABL-MW-1 - - - - - - - - - - - - - - - ABL-MW-3 X X X X X X X - X X X X X X X ABL-MW-4 X X X X X X X - X X X X X X X ABL-MW-5 X X X X X X X - X X X X X X X ABL-MW-6 - - - - - - - - - - - - - - - ABL-PZ-2S - - - - - - - - - - - - - - - ABL-PZ-2D - - - - - - - - - - - - - - - ABL-PZ-3S X X X X X X X - X X X X X X X PZ-18RD - - - - - - - - - - - - - - - MW-211 - - - - - - - - - - - - - - - MW-212 - - - - - - - - - - - - - - - MW-215 - - - - - - - - - - - - - - - MW-216 - - - - - - - - - - - - - - - Total 4 4 4 4 4 4 4 0 4 4 4 4 4 4 4 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2340B/6020B = Total Hardness (as CaCO3) by calculation; Calcium and Magnesium 6020B/7470A = Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, Silver, Mercury (Total and Filtered) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 4500 H+ B = pH 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids D7511 = Total Cyanide via ASTM 8270E = Polycyclic Aromatic Hydrocarbons 1668A = Polychlorinated Biphenyls (Congeners) FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) -14 - Groundwater Sampling Plan - BBP May 2023 2.4.2 Sample Quantities Table 13 presents a summary of the sample quantities for the Alcoa-Badin Landfill for each sampling event. Table 13: Alcoa-Badin Landfill Sample Quantities per Event Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Event 1 Groundwater 1677 16 2 1 4 2 0 25 Groundwater 9056Aa/4500F 16 2 1 4 2 0 25 Groundwater 9056Ab 10 1 1 4 2 0 18 Groundwater 353.2 10 1 1 4 2 0 18 Groundwater 4500P 10 1 1 4 2 0 18 Groundwater 2340B/6020B 4 1 1 4 2 0 12 Groundwater 6020B/7470A 4 1 1 4 2 0 12 Groundwater 6010D/6020B 8 1 1 4 2 0 16 Groundwater 2320B 10 1 1 4 2 0 18 Groundwater 4500 H+ B 4 1 1 4 2 0 12 Groundwater 5310B 4 1 1 4 2 0 12 Groundwater 2540D 4 1 1 4 2 0 12 Groundwater D7511 4 1 1 4 2 0 12 Groundwater 8270E 4 1 1 4 2 0 12 Groundwater 1668A 4 1 1 4 2 0 12 Groundwater FS 16 0 0 0 0 0 16 Event 2 Groundwater 1677 4 1 1 1 1 0 8 Groundwater 9056Aa/4500F 4 1 1 1 1 0 8 Groundwater 9056Ab 4 1 1 1 1 0 8 Groundwater 353.2 4 1 1 1 1 0 8 Groundwater 4500P 4 1 1 1 1 0 8 Groundwater 2340B/6020B 4 1 1 1 1 0 8 Groundwater 6020B/7470A 4 1 1 1 1 0 8 Groundwater 6010D/6020B 0 0 0 0 0 0 0 Groundwater 2320B 4 1 1 1 1 0 8 Groundwater 4500 H+ B 4 1 1 1 1 0 8 Groundwater 5310B 4 1 1 1 1 0 8 Groundwater 2540D 4 1 1 1 1 0 8 Groundwater D7511 4 1 1 1 1 0 8 Groundwater 8270E 4 1 1 1 1 0 8 Groundwater 1668A 4 1 1 1 1 0 8 -15 - Groundwater Sampling Plan - BBP May 2023 Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Groundwater FS 4 0 0 0 0 0 4 Notes: 1 One duplicate sample is to be collected per 10 primary field samples. 2 Matrix spike, matrix spike duplicate, and equipment blank samples are to be collected 1 per 20 primary field samples. 3 Field blank samples are to be collected each day of sampling; number is based on anticipated days required to complete sample collection. 4 Trip blank samples are required for each cooler containing 8260D (VOC) samples; number is based on anticipated number of coolers 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2340B/6020B = Total Hardness (as CaCO3) by calculation; Calcium and Magnesium 6020B/7470A = Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, Silver, Mercury (Total and Filtered) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 4500 H+ B = pH 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids D7511 = Total Cyanide via ASTM 8270E = Polycyclic Aromatic Hydrocarbons 1668A = Polychlorinated Biphenyls (Congeners) FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.5 OLD BRICK LANDFILL SWMU No. 3, the Old Brick Landfill, is located approximately 0.75 miles northeast of the Main Plant on a slope bordered by Badin Lake. Between 1915 to 1960, Main Plant waste materials were disposed on the slope. Since 1987, voluntary activities have been conducted to reduce direct contact with waste materials and potential contact between waste and surface water. These activities included the 1987 cover installation, the 1996 surface water diversion improvements, and the 1997 landslide and cover repairs. In 2007, a new cover and storm water management system was installed. The new cover and storm water management system eliminated contact between infiltrating storm water and potential waste material. Following the cover system installation, groundwater sampling results presented in the Phase 3 Report demonstrated the beneficial effects of the cover system upgrades. However, SWMU No. 3 was retained in the corrective action process due to the quantification of available cyanide in one well. 2.5.1 Sample Locations Table 14 presents a summary of the planned sample locations for the Old Brick Landfill. -16 - Groundwater Sampling Plan - BBP May 2023 Table 14: Old Brick Landfill Sample Locations Wells for Event 1 OBL-MW-1 OBL-MW-4 OBL-MW-2 OBL-MW-5 OBL-MW-3 OBL-MW-6 Table 15 presents the analyte list for each well for the Old Brick Landfill. Table 15: Old Brick Landfill Event 1 Analyte List Well 1677 9056Aa /4500F 9056Ab 353.2 4500P 2320B 6010D/ 6020B 5310B 2540D FS OBL-MW-1 X X - - - - - - - X OBL-MW-2 X X - - - - - - - X OBL-MW-3 X X - - - - - - - X OBL-MW-4 X X X X X X X X X X OBL-MW-5 X X X X X X X X X X OBL-MW-6 X X - - - - - - - X Total 6 6 2 2 2 2 2 2 2 6 Notes: 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.5.2 Sample Quantities Table 16 presents a summary of the sample quantities for the Old Brick Landfill for the sampling event. Table 16: Old Brick Landfill Sample Quantities Matrix Analyte/ Analytical Group Field Samples Field Duplicates1 Matrix Spikes/ Matrix Spike Duplicates2 Field Blanks3 Equipment Blanks2 Trip Blanks4 Total # Analyses Event 1 Groundwater 1677 6 1 1 2 1 0 11 Groundwater 9056Aa/4500F 6 1 1 2 1 0 11 Groundwater 9056Ab 2 1 1 1 1 0 6 Groundwater 353.2 2 1 1 1 1 0 6 Groundwater 4500P 2 1 1 1 1 0 6 Groundwater 2320B 2 1 1 1 1 0 6 -17 - Groundwater Sampling Plan - BBP May 2023 Groundwater 6010D/6020B 2 1 1 1 1 0 6 Groundwater 5310B 2 1 1 1 1 0 6 Groundwater 2540D 2 1 1 1 1 0 6 Groundwater FS 6 0 0 0 0 0 6 Notes: 1 One duplicate sample is to be collected per 10 primary field samples. 2 Matrix spike, matrix spike duplicate, and equipment blank samples are to be collected 1 per 20 primary field samples. 3 Field blank samples are to be collected each day of sampling; number is based on anticipated days required to complete sample collection. 4 Trip blank samples are required for each cooler containing 8260D (VOC) samples; number is based on anticipated number of coolers. 1677 = Available Cyanide 9056Aa/4500F = Fluoride (reported by both Methods) 9056Ab = Bromide, Chloride, Sulfate 353.2 = Nitrate, Nitrite 4500P = Orthophosphate 2320B = Alkalinity (Total, Carbonate, and Bicarbonate) 6010D = Silica (Filtered) 6020B = Aluminum, Calcium, Iron, Magnesium, Manganese, Potassium, Sodium (Filtered) 5310B = Dissolved Organic Carbon 2540D = Total Suspended Solids FS = Field Screening (Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential) 2.6 GROUNDWATER LEVEL GAUGING Depth to water level measurements will be collected during the first sampling event at the locations specified in Table 17 and illustrated in Figure 3. Table 17: Water Level Gauging Locations Alcoa-Badin Landfill Main Plant Old Brick Landfill ABL-MW-1 PZ-13 MW-1 MW-13 MW-27 BF-1 MW-205 OBL-MW-1 ABL-MW-2 PZ-14 MW-2 MW-14 MW-28 BF-2 MW-206 OBL-MW-2 ABL-MW-3 PZ-15 MW-2A MW-15 MW-29 BF-5 MW-207 OBL-MW-3 ABL-MW-4 PZ-16 MW-3 MW-16 MW-30 BF-8 MW-208 OBL-MW-4 ABL-MW-5 PZ-17 MW-4 MW-17 MW-31 MW-103 MW-209 OBL-MW-5 ABL-MW-6 PZ-19 MW-5 MW-18 MW-32 MW-104 MW-210 OBL-MW-6 ABL-PZ-1S PZ-18RD MW-6 MW-19 MW-33 MW-110 MW-211 ABL-PZ-1I MW-215 MW-6A MW-20 MW-35 MW-111 MW-212 ABL-PZ-ID MW-216 MW-7 MW-20A MW-37 MW-112 MW-213 ABL-PZ-2S MW-8 MW-21 MW-40 MW-200 MW-214 ABL-PZ-2D MW-9 MW-23 MW-46 MW-201 MW-217 ABL-PZ-3S MW-10 MW-24 MW-49 MW-202 MW-218 ABL-PZ-3I MW-11 MW-25 PZ-1 MW-203 MW-219 ABL-PZ-3D MW-12 MW-25A PZ-3 MW-204 MW-220 PZ-6 Groundwater data will be used to construct potentiometric surface maps. -18 - Groundwater Sampling Plan - BBP May 2023 3.0 SAMPLE DESIGNATION Sample labels are required for properly identifying samples for laboratory analysis. Label information will include the Project name, sample identification number (sample ID), the date and time of sampling, and requested analysis, as applicable. The sample numbering and nomenclature system will be as follows:  Three-digit Project code;  Two to five-digit alphanumeric location identifier code; and a  Four-digit alphanumeric sequential sample number. Examples of a sample label: ABP-MW001-F001 ABP-PZ002-D002 3.1 PROJECT CODE A unique, three-digit Project code will be used to identify the specific Project. This Project will use the following identifier:  ABP – Badin Business Park (former Alcoa-Badin Works facility);  ABL – Alcoa-Badin Landfill; and  OBL – Old Brick Landfill. 3.2 LOCATION IDENTIFIER CODE The location code will consist of a two to five-digit alphanumeric value and will correspond with the sample location ID; however, hyphens in the location name will be omitted in the location identifier code. In the event that samples are to be collected from locations that are not already established and permanent (i.e., a soil boring or temporary piezometer), then the following five-digit alphanumeric value will apply: the first two digits will indicate the type of location from which the sample was collected, and the next three digits will start with 001 and increase sequentially. Location codes may begin with the following two-digit acronym, as applicable:  CO – Container (drum, roll-off, slurry box, etc.)  MW – Monitoring well  PZ – Piezometer  RW – Recovery well -19 - Groundwater Sampling Plan - BBP May 2023  SS – Surface soil  SW – Surface water Location codes are unique to a Project, so if a sample type was previously collected, the three-digit code should follow sequentially with the previously collected samples associated with that specific location code. This means that field teams will coordinate with the data manager prior to going into the field to reduce the chance of duplicate naming of location. 3.3 SEQUENTIAL SAMPLE NUMBER The sequential sample number will consist of one letter followed by three numbers. The first digit, a letter, will indicate the type of sample being collected. Valid sample types are as follows:  F – Normal field sample  D – Field duplicate  M – Matrix spike and matrix spike duplicate  B – Field blank  T – Trip blank  E – Equipment blank The following three digits will be a sequential number starting with 100. For this Project, the initial groundwater sampling event will serve as the first sequential number, 100, followed by 101 in the following event for each sample collected as part of that event. -20 - Groundwater Sampling Plan - BBP May 2023 4.0 SAMPLE EQUIPMENT AND PROCEDURES Prior to purging, a round of groundwater level measurements will be collected from 100 of the 126 wells available at the Facility within a 48-hour period. Each well will be gauged from the top of casing with an electronic resistivity probe, which measures the groundwater level. The water levels will be measured in wells before any actions are performed on the well which may affect water levels. The total depth of each well will also be measured. Measurements will be made to a precision of +/- 0.01 ft. The measuring device will be cleaned prior to use in each well. The water levels in the wells will be made consecutively to support comparison of measurements and calculated elevations between wells. Samples will be collected using a portable (non-dedicated) pumps using low-flow purging and sampling procedures. Dedicated water discharge tubing lines will be used at each well to reduce the level of decontamination required between wells. Each well will be purged at a relatively low rate to reduce drawdown. The purge water will be field-tested for pH, turbidity, specific conductance, oxidation-reduction potential (ORP), and temperature. Well purging will continue until the field parameters have stabilized [i.e., ±20 millivolts for ORP, ±3 percent for specific conductance, ≤10 NTU or ±10 percent if >10 NTU for turbidity, ±5°C for temperature; and ±0.20 Standard Units (S.U.) for pH] across three successive readings taken three to five minutes apart. If the recharge rate of the well is less than the lowest achievable pumping rate and the well is purged dry, a sample will be collected as soon as the water level has recovered sufficiently to collect the sample, even if the parameters have not stabilized. Samples will be collected directly into laboratory-prepared bottles, labeled, and placed on ice in sealed coolers for delivery to a North Carolina-certified laboratory for analysis. Reusable equipment used to collect groundwater samples will be decontaminated before use at another well. Chain-of-custody procedures will be followed during times of sampling and subsequent analysis. Purge water removed will be containerized in 55-gallon drums, labeled, and stored at a secure Facility location pending the receipt of laboratory analytical results to determine appropriate disposal. -21 - Groundwater Sampling Plan - BBP May 2023 4.1 QUALITY ASSURANCE SAMPLING The following quality assurance/quality control (QA/QC) samples may be collected in the field during the investigations:  Field Duplicate Samples are independent samples that are collected as close as possible to the same point in time and space. They are two separate samples taken from the same source, stored in separate containers, and analyzed independently. One groundwater field duplicate sample will be collected per ten field samples, or portion thereof, as part of each sampling event. Field duplicates will be submitted to the laboratory as blind duplicates, that is, the source of the field duplicate sample will remain unknown to the laboratory;  Matrix Spike (MS) and Matrix Spike Duplicate (MSD) samples, performed by the laboratory, are used to evaluate the accuracy and precision of the analytical method with respect to the sample matrix for organic analyses. MS and matrix duplicate (MD) samples are used to evaluate the accuracy and precision of the analytical method with respect to the sample matrix for inorganic analyses. A MS, MSD, or MD that did not meet the laboratory established accuracy or precision criteria is indicative of possible matrix interference. Only matrix QC samples selected from media specific to this Project are to be reported. Procedures for the MS, MSD, and MD are performed according to the same requirements of the United States Environmental Protection Agency (U.S. EPA) approved methods. One MS and MSD sample will be collected per twenty field samples, or portion thereof, as part of each sampling event;  A Trip Blank [volatile organic compounds (VOCs) only] is a reagent water sample prepared by the laboratory free of VOCs that is placed into a volatile organic analysis (VOA) vial and shipped to and from the field with the sample vials. The purpose of this sample is to evaluate any contamination that may have been picked up in transit and storage. If VOCs analysis is performed, one trip blank sample will be analyzed from each cooler containing samples submitted for VOCs analysis as part of each sampling event; and  Equipment Blank (or rinsate blank) is created by pouring reagent water through or onto the sampling equipment following decontamination. This blank demonstrates the cleanliness of the sampling equipment and/or the effectiveness of the decontamination process. A rinsate blank is not collected if dedicated or disposable sampling equipment is used. If non-disposable sampling equipment is used, one rinsate blank sample will be collected per twenty field samples, or portion thereof, as part of each sampling event. Additional QA samples will be analyzed by the laboratory. Specifically, the laboratory will follow the quality objectives for precision, accuracy, representativeness, comparability, completeness, and method detection limits as set forth in the laboratory QA Manual. Laboratory internal QC results will include information about agreement between replicate analyses, spike, and surrogate recoveries. Analysis of laboratory control samples, method blanks, matrix spikes, and duplicates -22 - Groundwater Sampling Plan - BBP May 2023 will also be included with each analytical batch in accordance with analytical method requirements. 4.2 STANDARD OPERATING PROCEDURES The specific field sampling equipment and procedures that will be used to obtain the required data are provided as appendices. The procedure descriptions related to implementation of the tasks are attached as follows:  Appendix A: Ground-Water Elevation Monitoring Procedures o U.S. EPA Laboratory Services and Applied Science Division (LSASD) Operating Procedure: Groundwater Level and Well Depth Measurement (LSASDPROC-105- R4, May 15, 2020).  Appendix B: Groundwater Sampling Procedures (Low-Flow Sampling) o U.S. EPA Science and Ecosystem Support Division (SESD) Operating Procedure: Pump Operation (SESDGUID-203-R4, March 14, 2018); and o U.S. EPA SESD Operating Procedure: Groundwater Sampling (SESDPROC-301- R4, April 26, 2017).  Appendix C: Field Instrument Calibration, Operation, and Maintenance Procedures o U.S. EPA LSASD Operating Procedure: In Situ Water Quality Monitoring (LSASDPROC-111-R5, April 22, 2022); o U.S. EPA LSASD Operating Procedure: Field Measurement of Dissolved Oxygen (LSASDPROC-106-R4, April 9, 2021); o U.S. EPA LSASD Operating Procedure: Field Measurement of Oxidation- Reduction Potential (ORP) (LSASDPROC-113-R3, December 17, 2021); o U.S. EPA LSASD Operating Procedure: Field pH Measurement (LSASDPROC- 100- R5, July 23, 2020); o U.S. EPA LSASD Operating Procedure: Field Specific Conductance Measurement (LSASDPROC-101-R7, May 5, 2020); o U.S. EPA LSASD Operating Procedure: Field Temperature Measurement (LSASDPROC-102-R6, April 8, 2022 ); and o U.S. EPA LSASD Operating Procedure: Field Turbidity Measurement (LSASDPROC-103-R5, November 3, 2021).  Appendix D: Equipment Decontamination Procedures o U.S. EPA LSASD Operating Procedure: Field Equipment Cleaning and Decontamination (LSASDPROC-205-R4, June 22, 2020). Field activities will be documented in accordance with the U.S. EPA guidance. Field data will be documented in either field forms or a field logbook. In the event that field personnel determine that any of the procedures presented in the appendices are inappropriate, inadequate or impractical -23 - Groundwater Sampling Plan - BBP May 2023 and that other procedures are be used, the variant procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Field forms and logbooks will be tracked and stored electronically in the Project file. -24 - Groundwater Sampling Plan - BBP May 2023 5.0 SAMPLE HANDLING AND ANALYSIS Sample handling and custody requirements are intended to maintain control and document possession of environmental samples following sample collection through shipments to the analytical laboratory. Samples collected will be placed into laboratory prepared containers and preserved as noted on Table 178. Table 18: Sample Containers, Preservation, and Hold Times Analyte/ Analyte Group Method/ SOP Container(s) (number, size & type per sample, preservative) Minimum Volume Required Analytical Holding Time Alkalinity 2320B One (1) Plastic 250ml - unpreserved 100 mL 14 Days Anions: Fluoride 4500F One (1) Plastic 125 mL oblong - unpreserved 25 mL 28 Days Anions: Bromide, Chloride, Fluoride, Sulfate 9056A One (1) Plastic 125 mL oblong - unpreserved 20 mL 28 Days PCB Congeners 1668A Two (2) Amber Glass 1 liter - unpreserved 2000 mL 1 Year Cyanide, Available 1677 Two (2) Amber Plastic 125ml - with Sodium Hydroxide 250 ml 14 Days Cyanide, Total D7511_12 One (1) Plastic 250ml - with Sodium Hydroxide 250 mL 14 Days Mercury - Total and Field Filtered 7470A One (1) Plastic 250ml - with Nitric Acid 100 mL 28 Days Metals (Silica) - Field Filtered 6010D One (1) Plastic 250ml - unpreserved 100 mL 180 Days Metals (Site List) - Field Filtered 6020B One (1) Plastic 250ml - with Nitric Acid 100 mL 180 Days Metals (RCRA) – Total and Field Filtered 6020B One (1) Plastic 250ml - with Nitric Acid 100 mL 180 Days Nitrogen, Nitrate-Nitrite 353.2_Pres One (1) Plastic 250ml - with Sulfuric Acid 30 mL 28 Days Nitrogen, Nitrite 353.2_Nitrite One (1) Plastic 125mL - unpreserved 50 mL 48 Hours Dissolved Organic Carbon - Field Filtered SM5310_DOC_B Three (3) VOA Vial 40ml Amber - with Sulfuric Acid 80 mL 28 Days Orthophosphate 4500_P_F_Ortho One (1) Plastic 125mL - unpreserved 25 mL 48 Hours pH SM4500_H+ One (1) Plastic 125mL - unpreserved 5 mL IMMEDIATELY PAHs 8270E_SIM Two (2) Amber Glass 250ml - unpreserved 500 mL 7 Days Total Hardness (as CaCO3) by calculation SM2340B One (1) Plastic 250ml - with Nitric Acid 50 mL 6 Months Total Hardness Metals (Ca/Mg) 6020B One (1) Plastic 250ml - with Nitric Acid 100 mL 180 Days Total Suspended Solids 2540D One (1) Plastic 1 L - unpreserved 1000 mL 7 Days Volatile Organic Compounds 8260D Three (3) VOA Vial 40ml Glass - with Hydrochloric Acid; Zero headspace 120 mL 14 Days Field Screening See Section 4.0 Not applicable Not applicable Not applicable -25 - Groundwater Sampling Plan - BBP May 2023 Notes: SOP = Standard Operating Procedure mL = milliliter PCB = Polychlorinated Biphenyls Metals (Site List) = Calcium, Iron, Magnesium, Manganese, Potassium, and Sodium Metals (RCRA) = Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, and Silver VOA = Volatile Organic Analyte PAHs = Polycyclic Aromatic Hydrocarbons CaCO3 = Calcium Carbonate Ca/Mg = Calcium and Magnesium Field Screening = Dissolved Oxygen, Specific Conductance, pH, Temperature, and Oxidation Reduction Potential Procedures for sample handling and analysis are provided in Appendix E: Sample Handling, Packing, and Shipping Procedures - U.S. EPA LSASD Operating Procedure: Packing, Marking, Labeling and Shipping of Environmental and Waste Samples (LSASDPROC-209-R4, February 23, 2020). Following collection, each sample will be placed on ice in shipping coolers pending transport to the laboratory. Samples will be accompanied by a properly completed chain-of-custody form. Each sample identification will be listed on the chain-of-custody form. When transferring the possession of samples, the individuals relinquishing and receiving the samples will sign and record the date and time on the form. The chain-of-custody form documents sample custody transfers from the sampler to another person, to the laboratory, or to/from a secure storage area. Example forms are provided as Appendix F The samples will be shipped to the laboratory via a mail carrier or courier service, when possible on the day they are collected. Exceptions to this procedure will be for samples collected after the courier service has picked up the last shipment for the day or if the sampler cannot make the last drop-off time for a mail carrier service. If samples are not shipped/transported to the laboratory the same day the samples are collected in the field, additional ice will be placed in the coolers, and the coolers will be kept in a designated secure area until they are shipped/transported to the laboratory. -26 - Groundwater Sampling Plan - BBP May 2023 6.0 SCHEDULE AND REPORTING A tentative schedule for field activities is presented in Table 19: Table 19: Tentative Schedule Event Quarter Event 1 2nd Quarter 2023 Event 2 3rd Quarter 2023 The above schedule may be modified based on the results of the preceding sampling events. Modifications to the schedule will be communicated to the NCDEQ. After the completion of each groundwater sampling event, a report will be prepared describing the field activities including results of any sampling performed. FIGURES ApproximateAlcoa-Badin LandfillBoundary ApproximateMain PlantBoundary ApproximateOld Brick LandfillBoundary DRAWN BY:DATE:CHECKED BY:DWG SCALE:APPROVED BY:PROJECT NO: FIGURE NO:APRIL 13, 2023 1 SITE LOCATION MAP 0 1,250 2,500Feet 1 " = 2,500 'P:\300-000\300-226\-GIS\Maps\300-226.0022 - GWMP\300-226.0017 Figure 1 - Location.mxd - 4/13/2023 - 4:26:16 PM (bhardin)!IIl NORTH Legend Approximate Main Plant BoundaryApproximate Alcoa-Badin Landfill BoundaryApproximate Old Brick Landfill Boundary 300-226 SOURCE: WORLD STREET MAPARCGIS MAP SERVICE: HTTP://GOTO.ARCGISONLINE.COM/MAPS/WORLD_STREET_MAP. LAST ACCESSED: 4/13/2023 2704 Cherokee Farm Way, Suite101 - Knoxville, TN 37920865-977-9997 865-774-7767www.cecinc.comBRH MWW JMB* BADIN BUSINESS PARK FACILITYHWY 740BADIN, NORTH CAROLINA * Hand signature on file DRAWN BY:DATE:APPROVED BY:PROJECT NO:FIGURE NO:2 BADIN BUSINESS PARK FACILITYHWY 740BADIN, NORTH CAROLINA BRH4/18/2023 WELLS IN SAMPLING PROGRAM MWW JMB*300-226CHECKED BY:SCALE: NO DATE DESCRIPTION-- SUBMITTAL & REVISION RECORD ----P:\300-000\300-226\-GIS\Maps\300-226.0022 - GWMP\Wells in Sample Program.mxd 4/18/2023 10:22 AM (bhardin)0 500 1,000 SCALE IN FEET LEGEND REFERENCEUSGS TOPOGRAPHIC MAP/ ARCGIS MAP SERVICE: HTTP://GOTO.ARCGISONLINE.COM/MAPS/USA_TOPO_MAPS, ACCESSED 4/18/2023 !A!A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A!A !A !A!A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A !A !A !A !A MW-46MW-29 MW-45 MW-21 MW-9 MW-8 MW-6 MW-5 MW-4 MW-3 BF-5 BF-2 BF-1 MW-2 MW-1 MW220 MW218 MW216 MW215 MW211 MW210 MW209 MW208 MW205 MW204 MW203 MW202 MW201 MW200 MW-35 MW-31 MW-30 MW-6AMW-2A MW-27 MW-23 MW-20 MW-19 MW-18 MW-15 MW-14 MW-13 MW-11 MW-10 PZ-19 PZ-17 PZ-15 MW-212 PZ18RD MW-110 MW-104 MW-103 OBL-MW-6 OBL-MW-5 OBL-MW-4 OBL-MW-3 OBL-MW-2OBL-MW-1 ABL-MW-6 ABL-MW-5 ABL-MW-4 ABL-MW-3 ABL-MW-1 ABL-PZ-3(S) ABL-PZ-2(S) ABL-PZ-2 (D,l) MW-37 MW-33 MW-32 MW-25 MW-16MW-12 MW-217 MW-111 MW-112 MW-25A MW-20A BF-8 Main Plant - Central and SouthernPortion Sampling Locations Alcoa-Badin LandfillSampling Locations Main Plant - Northwest ValleySampling Locations Old Brick LandfillSampling LocationsMain Plant - West Fill AreaSampling Locations Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community NORTH!a !A Monitoring Well !A Piezometer 1 " = 700 ' 2704 Cherokee Farm Way, Suite101 - Knoxville, TN 37920865-977-9997 865-774-7767www.cecinc.com * Hand signature on file DRAWN BY:DATE:APPROVED BY:PROJECT NO:FIGURE NO:3BRH4/13/2023 WELLS IN GAUGING PROGRAM MWW JMB*300-226CHECKED BY:SCALE: NO DATE DESCRIPTION-- SUBMITTAL & REVISION RECORD ----P:\300-000\300-226\-GIS\Maps\300-226.0022 - GWMP\Wells in Gauging Program.mxd 4/13/2023 16:28 PM (bhardin)0 500 1,000 SCALE IN FEET LEGEND REFERENCE USGS TOPOGRAPHIC MAP/ ARCGIS MAP SERVICE: HTTP://GOTO.ARCGISONLINE.COM/MAPS/USA_TOPO_MAPS, ACCESSED 4/13/2023 !A!A !A !A!A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A!A !A !A!A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A !A!A !A !A!A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A !A!A !A !A !A !A !A !A !A !A !A !A!A !A PZ-6MW-7 PZ-3 MW-9 MW-8 MW-4 MW-3 BF-5 BF-1 MW-2 MW-1 PZ-5 MW-46 MW-28 PZ-16 PZ-13 MW220 MW218 MW216 MW215 MW211 MW210 MW209 MW208 MW205 MW204 MW203 MW202 MW200 MW-34 MW-32 MW-31 MW-30 MW-27 MW-19 MW-18 MW-15 MW-14 MW-13 PZ-19 PZ-15 MW-213 MW-207 MW-206 MW-212 PZ18RD MW-111 MW-103 OBL-MW-6 OBL-MW-5 OBL-MW-3 OBL-MW-2OBL-MW-1 ABL-MW-6 ABL-MW-5 ABL-MW-4 ABL-MW-3 ABL-MW-1 ABL-PZ-1(S) ABL-PZ-3(S) PZ-1 MW-6 MW-5 MW-21 MW-17 MW-24 MW201 MW-49 MW-40 MW-37 MW-33 MW-6A MW-2A MW-25 MW-23MW-20 MW-16 MW-12 MW-11 MW-10 PZ-17 PZ-14 MW-219 MW-217 MW-112 MW-25A MW-20A MW-110 MW-104 ABL-MW-2 OBL-MW-4 ABL-PZ-2(S) ABL-PZ-1(D,I) ABL-PZ-3(D,I) ABL-PZ-2 (D,l) MW-29 BF-8 BF-2 Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community NORTH!a !A Monitoring Well !A Piezometer BADIN BUSINESS PARK FACILITYHWY 740BADIN, NORTH CAROLINA 1 " = 700 ' 2704 Cherokee Farm Way, Suite101 - Knoxville, TN 37920865-977-9997 865-774-7767www.cecinc.com * Hand signature on file APPENDIX A GROUNDWATER ELEVATION MONITORING PROCEDURES LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 1 of 8 Purpose This document describes general and specific procedures, methods and considerations to be used and observed when determining water levels and depths of wells. Scope/Application The procedures contained in this document are to be used by field investigators to measure water levels and depths of wells. On the occasion that LSASD field investigators determine that any of the procedures described in this section are either inappropriate, inadequate or impractical and that another procedure must be used for water level or depth determination, the variant procedure(s) will be documented in the field log book and the subsequent investigation report, along with a description of the circumstances requiring its use Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Groundwater Level and Well Depth Measurement ID: LSASDPROC-105-R4 Issuing Authority: LSASD Field Branch Chief Effective Date: May 15, 2020 Review Date: May 15, 2024 Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 2 of 8 TABLE OF CONTENTS Purpose 1 Scope/Application .....................................................................................................................................1 1 General Information..........................................................................................................................3 1.1 Documentation/Verification .............................................................................................................3 1.2 General Precautions..........................................................................................................................3 1.2.1 Safety ...............................................................................................................................................3 2 Quality Control Issues.......................................................................................................................3 3 Water Level and Depth Measurement Procedures............................................................................4 3.1 General ..............................................................................................................................................4 3.2 Specific Groundwater Level Measurement Techniques...................................................................5 3.3 Special Considerations for Water Level Measurements at Sites with Shallow Groundwater Gradient.............................................................................................................................................5 3.4 Total Well Depth Measurement Techniques ....................................................................................5 3.5 Equipment Available ........................................................................................................................6 4 Establishment of Top of Casing Elevations ......................................................................................6 5 References.........................................................................................................................................6 6 Revision History ...............................................................................................................................7 Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 3 of 8 1 General Information 1.1 Documentation/Verification This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD Local Area Network. The Document Control Coordinator is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance. 1.2 General Precautions 1.2.1 Safety Proper safety precautions must be observed when measuring water levels in wells and determining their depths. Refer to the LSASD Safety, Health and Environmental Management Program Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 1.2.2 Procedural Precautions The following precautions should be considered when measuring water levels and depths of wells: Special care must be taken to minimize the risk of cross-contamination between wells when conducting water level and depth measurements. This is accomplished primarily by decontaminating the sounders or other measuring devices between wells, according to LSASD Operating Procedure for Field Equipment Cleaning and Decontamination, (LSASDPROC-205) and maintaining the sounders in clean environment while in transit between wells. Water levels and well depths measured according to these procedures should be recorded in a bound logbook dedicated to the project as per LSASD Operating Procedure for Logbooks (LSASDPROC-010). Serial numbers, property numbers or other unique identification for the water level indicator or sounder must also be recorded. 2 Quality Control Issues There are several specific quality control issues pertinent to conducting water level and depth measurements at wells. These are: Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 4 of 8 Devices used to measure groundwater levels should be verified annually against a National Institute of Standards and Technology (NIST) traceable measuring tape. These devices should check to within 0.01 feet per 10 feet of length with an allowable error of 0.03 feet in the first 30 feet. Before each use, these devices should be prepared according to the manufacturer’s instructions (if appropriate) and checked for obvious damage. All verification and maintenance data should be documented electronically or recorded in a logbook maintained at the Field Equipment Center (FEC) as per the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-108). The functional check and tape length verification should be performed according to the instructions included in LSASDFORM-043, Well Sounder Function Check and Verification, which also includes the form for recording the required information. These devices should be decontaminated according to the procedures specified in LSASD Operating Procedure for Field Equipment Cleaning and Decontamination (LSASDPROC-205) prior to use at the next well. 3 Water Level and Depth Measurement Procedures 3.1 General The measurement of the groundwater level in a well is frequently conducted in conjunction with ground water sampling to determine the phreatic water surface. This potentiometric surface measurement can be used to establish ground water direction and gradients. Groundwater level and well depth measurements are needed to determine the volume of water or drawdown in the well casing for proper purging. All groundwater level and well depth measurements should be made relative to an established reference point on the well casing and should be documented in the field records. This reference point is usually identified by the well installer using a permanent marker for PVC wells, or by notching the top of casing with a chisel for stainless steel wells. By convention, this marking is usually placed on the north side of the top of casing. If no mark is apparent, the person performing the measurements should take both water level and depth measurements from the north side of the top of casing and note this procedure in the field log book. To be useful for establishing groundwater gradient, the reference point should be tied in with the NAVD88 (North American Vertical Datum of 1988) or a local datum. For an isolated group of wells, it is acceptable to use an arbitrary datum common to all wells in that group. Water levels should be allowed to equilibrate prior to measurement after removing sealing caps. There are no set guidelines and appropriate equilibration times can range from minutes to hours depending on well recharge, local geology and topography, and project objectives. Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 5 of 8 3.2 Specific Groundwater Level Measurement Techniques Measuring the depth to the phreatic ground water surface can be accomplished by the following methods. Method accuracies are noted for each of the specific methods described below. Electronic Water Level Indicators – These types of instruments consist of a spool of dual conductor wire, a probe attached to the end and an indicator. When the probe comes in contact with the water, the circuit is closed and a meter light and/or audible buzzer attached to the spool will signal contact. Penlight or 9-volt batteries are normally used as a power source. Measurements should be made and recorded to the nearest 0.01 foot. Other Methods – There are other types of water level indicators and recorders available on the market, such as weighted steel tape, chalked tape, sliding float method, air line pressure method and automatic recording methods. These methods are primarily used for closed systems or permanent monitoring wells. Acoustic water level indicators are also available which measure water levels based on the measured return of an emitted acoustical impulse. Accuracies for these methods vary and should be evaluated before selection. Any method not capable of providing measurements to within 0.1 foot should not be used. 3.3 Special Considerations for Water Level Measurements at Sites with Shallow Groundwater Gradient Groundwater gradients at some sites can be very shallow and if gradient and groundwater flow pattern (gradient direction) determination are part of the project objectives, it is critical that groundwater level measurements obtained from wells are as accurate as possible. Special care should be taken to allow the water level to equilibrate after removing sealing caps and the same sounder should be used for all measurements, if possible. The sounding activity should be coordinated to allow all wells to be sounded within the minimum possible time. This is particularly important in areas with potential tidal influences. 3.4 Total Well Depth Measurement Techniques The well sounder, weighted tape or electronic water level indicators can be used to determine the total well depth. This is accomplished by lowering the tape or cable until the weighted end is felt resting on the bottom of the well. Because of tape buoyancy and weight effects encountered in deep wells with long water columns, it may be difficult to determine when the tape end is touching the bottom of the well and sediment in the bottom of the well can also make it difficult to determine total depth. Care must be taken in these situations to ensure accurate measurements. The operator may find it easier to allow the weight to touch bottom and then detect the ‘tug’ on the tape while lifting the weight off the well bottom. All total depth measurements must be made and recorded to the nearest 0.1 foot. As a cautionary note, when measuring well depths with the electronic water level indicators, the person performing the measurement must measure and add the length of the probe beneath the circuit closing electrodes to the depth measured to obtain the true depth. This is necessary because the tape distance markings are referenced to the electrodes, rather than the end of the probe. For electronic sounders maintained at the LSASD FEC, the sounder reel will be marked with the appropriate additional length identified as the ‘TD adder’. Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 6 of 8 3.5 Equipment Available The following equipment is available for ground water level and total depth measurements: Weighted steel measuring tapes Electronic water level indicators 4 Establishment of Top of Casing Elevations To establish groundwater surface elevations, the measured distance from the top of casing to the water surface is subtracted from the well top of casing (TOC) elevation. Obtaining accurate TOC elevations is crucial to developing an accurate groundwater surface elevation map and determination of groundwater flow direction. The only acceptable means of surveying well TOC elevations is differential leveling conducted to third order standards. Third order differential leveling has allowable error defined by the following formula: ()= 0.05 × () This work must be conducted with an auto level as the leveling instrument. Surveying TOC elevations with a total station or survey-grade GPS will not provide the requisite accuracy. When adding wells to a monitoring network, it is permissible to tie the new well elevations to the known TOC elevations of existing wells in the network. The elevations of several wells in the existing network should be checked to assure that the relative differences in elevation match the recorded elevation data. Generally, the ground surface elevations at each well should be surveyed at the same time. 5 References LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-108, Most Recent Version LSASD Operating Procedure for Field Equipment Cleaning and Decontamination, LSASDPROC-205, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region LSASD, Athens, GA, Most Recent Version Uncontrolled When Printed LSASDPROC-105-R4 Groundwater Level and Well Depth Measurement Effective Date: May 15, 2020 Page 7 of 8 6 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Document Control Coordinator on the LSASD local area network (LAN). History Effective Date LSASDPROC-105-R4, Groundwater Level and Well Depth Measurement, replaces SESDPROC-105-R3 General: Corrected any typographical, grammatical, and/or editorial errors. Updated document template and naming convention. Changed references to SESD to LSASD and FSB to ASB due to organizational name changes from Agency re-alignment. Reformatted and updated naming convention. May 15, 2020 SESDPROC-105-R3, Groundwater Level and Well Depth Measurement, replaces SESDPROC-105-R2 General: Corrected any typographical, grammatical, and/or editorial errors. Title Page: Author changed from Tim Simpson to Brian Striggow. Changed the Field Quality Manager from Bobby Lewis to Hunter Johnson. Updated cover page to represent LSASD reorganization. John Deatrick was not listed as the Chief of the Applied Services Branch Section 4: Added section on the Establishment of Well Top of Casing Elevations. November 3, 2016 SESDPROC-105-R2, Groundwater Level and Well Depth Measurement, replaces SESDPROC-105-R1 January 29, 2013 SESDPROC-105-R1, Groundwater Level and Well Depth Measurement, replaces SESDPROC-105-R0 November 1, 2007 SESDPROC-105-R0, Groundwater Level and Well Depth Measurement, Original Issue February 05, 2007 Uncontrolled When Printed APPENDIX B GROUNDWATER SAMPLING PROCEDURES Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 1 of 13 Region 4 U.S. Environmental Protection Agency Science and Ecosystem Support Division Athens, Georgia Operating Procedure Title: Pump Operation ID: SESDGUID-203-R4 Issuing Authority: Chief, Field Services Branch Effective Date: March 14, 2018 Purpose This document describes procedures, methods and considerations to be used and observed when operating a variety of pumps that may be used for purging monitoring wells and for collecting samples of aqueous phase environmental media, including groundwater, surface water and certain wastewaters, for field screening or laboratory analysis. Scope/Application The procedures contained in this document are to be used by field personnel when using pumps during the process of collecting samples of aqueous phase environmental media in the field. On the occasion that SESD field personnel determine that any of the procedures described in this section cannot be used to obtain samples of the particular media of interest, and that another method or pump must be used to obtain said sample, use of the variant pump and/or procedure will be documented in the field log book, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. While this SOP may be informative, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 2 of 13 TABLE OF CONTENTS 1 Geotech Geopump™ Peristaltic Pump ................................................................... 3 1.1 General........................................................................................................................................ 3 1.2 Operation .................................................................................................................................... 3 1.3 Sampling with a Peristaltic Pump .............................................................................................. 4 2 Small Diameter Electric Submersible Pumps ........................................................ 5 2.1 General........................................................................................................................................ 5 2.2 Safety ........................................................................................................................................... 5 2.3 Pre-Loadout Checkout Procedures ............................................................................................ 6 2.4 Operation .................................................................................................................................... 6 2.5 Maintenance and Precautions ................................................................................................... 6 2.6 Trouble Shooting ........................................................................................................................ 7 3 Geotech Portable Bladder Pump ............................................................................. 8 3.1 General........................................................................................................................................ 8 3.2 Operation .................................................................................................................................... 8 3.3 Trouble Shooting ........................................................................................................................ 9 4 Geoprobe® Model MBP 470 Mechanical Bladder Pump ................................... 10 4.1 General.......................................................................................................................................10 4.2 Operations ..................................................................................................................................10 5 Inertial Pump (Geoprobe® or Waterra®) ........................................................... 12 5.1 General.......................................................................................................................................12 5.2 Operation ...................................................................................................................................12 6 References ................................................................................................................ 13 7 Revision History ...................................................................................................... 13 Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 3 of 13 1 Geotech Geopump™ Peristaltic Pump 1.1 General These pumps are generally small, light-weight, portable and are powered by 12-volt batteries. The limit of suction is approximately 25 - 27 feet of vertical separation between the pump and water surface. They are appropriate for surface water sampling and for groundwater sampling where relatively small volumes of water are required for purging and sampling, and the water level is within the limit of suction. 1.2 Operation l. The Geopump has two drive locations that the roller pump head can be fastened depending on anticipated use. In most cases the pump head should be attached in the 0-600RPM drive location. Where very low flow rates and fine control is required, the pump head can be attached to the 0-300 RPM drive location. 2. Connect the pump power cable to a 12 volt power source. Briefly turn the pump on to test. 3. Open the pump head with the lever and place a clean 9”-12” length of Silastic® flexible tubing in the head v-slots and reclose the head. New Silastic® tubing should be used for each sample. When the pump is run for extensive periods, it may be necessary to replace the Silastic® tubing or reposition it on the rollers. 4 Attach sample tubing approximately one inch into the Silastic® tubing. 5. Deploy the lower end of the sample tubing to the desired point in the well. This would be the top-of-water for the multi-volume purge method or to the mid-screen for the Low-Flow method. 6. Connect a short piece of discharge tubing from the pump-head Silastic® tubing to a measuring bucket. 7. Set the direction switch on the pump face in the direction of desired pump flow. Turn on the pump and set the rheostat to the desired pumping rate. For the multi-volume purge method, the rate will generally be a relatively fast rate that the well will sustain without elevating turbidity. For the low-flow purge method the pump rate is established at a slower rate to maintain a minimal and stable drawdown level. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 4 of 13 1.3 Sampling with a Peristaltic Pump It is not acceptable to collect samples for organic compounds analyses through the flexible tubing used in the pump head due to possible sorption of contaminants and contribution of stray organic compounds to the sample. When collecting samples for semi-volatile organic compound analyses it is necessary to use a vacuum container placed in the sample line. Volatile organic compounds must be sampled using the ‘soda-straw’ method. The use of the vacuum container and the ‘soda-straw’ method is explained in Section 3.7.1 of the Groundwater Sampling Procedure SESDPROC-301. Samples of some inorganic constituents (i.e., metals and cyanide) may be collected directly through the tubing, if the tubing has been blanked for the project contaminants of interest. SESD routinely blanks tubing prior to use in accordance with the Field Sampling Quality Control Procedure, SESDPROC-011, so a field tubing rinse blank is generally not required. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 5 of 13 2 Small Diameter Electric Submersible Pumps 2.1 General Small diameter submersible pumps are used in wells of 2” diameter and larger. They are especially useful where large volumes of water are to be removed or when the groundwater surface is a large distance below ground surface. Commonly used pumps are the Grundfos® Redi-Flo2, the Geotech GeoSub, and the various ‘Monsoon’ style pumps. Other pumps are acceptable if constructed of suitable materials. Included within this category is the Grundfos® Redi-Flo2 small diameter electric submersible pump. With a diameter of approximately 1.75 inches, it is designed to be used in 2-inch diameter and larger wells. (Note: If used in any well larger than 4-inch diameter, this pump must be equipped with a cooling shroud to prevent the pump from overheating. If the pump overheats, internal sensors shut-off the pump it will not be operable until it cools to a temperature within the operating range). The Redi-Flo2® is a variable speed pump capable of providing pump rates from less than 100 ml/minute to in excess of 8 gallons per minute. The Redi-Flo2 pump, depending on the controller being used, operates with either 115v or 220v power. The pump rate is controlled by adjusting the frequency of the current going to the pump motor. It is a light-weight pump and can be easily handled by one person when lowering, but two people are generally needed when removing the pump, one to pull and another to reel in the hose and power lead. 2.2 Safety 1. Place the generator on dry ground or plastic sheeting as far as practical from the well, in the down-wind direction. 2. Inspect the electrical extension cord, as well as the lead to the pump, for frays, breaks, exposed wiring, etc. 3. Where appropriate, check the head space of the well for the presence of an explosive atmosphere with a combustible gas meter, or for vapors with a PID/FID instrument. 4. Wear rubber boots in wet areas to insulate against shock hazards. 5. Take care not to touch steel well casings, the controller housing, cabling, or other metal objects while the pump is energized. 6. If purge water is not collected, direct the discharge away from the well and generator, preferably down gradient of the area. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 6 of 13 7 Make sure that the generator is set to the proper voltage. 8. Do not add gasoline or oil to the generator while it is running. 9. Store and transport fuel in approved Type II gas cans. Store the fuel, generator, and oil in a trailer dedicated to this type of equipment. 10. Do not haul this equipment in the back of any passenger vehicle or with any sampling equipment or containers. 2.3 Pre-Loadout Checkout Procedures 1. Check the oil and gasoline in the generator. The fuel capacity for the portable Honda generator is 0.95 US Gallons (3.6 L). 2. Take the generator outside and start. Place a load on the generator, if possible. 3. Inspect the pump and all hoses, rope, and electrical cord and connections. 2.4 Operation 1. Place the pump, the controller, and enough hose for the measured well depth on plastic sheeting next to the well. Set the generator in a dry, safe location downwind of the well, but do not plug the cord from the controller into the generator. 2. Lower the pump, power lead, and hose into the well, placing the pump approximately five feet into the water column. 3. Start the generator, then connect the power cord from the pump controller. Make sure the proper voltage has been selected. 4. After starting the pump, closely observe operation to determine if drawdown is occurring in the well. If the water level is not pulled down, raise the pump in the water column one to two feet from the top of the water column and continue to purge. If the water level drops, however, lower the pump to keep up with the drawdown. Do not allow the pump to run dry. This condition can create a thermal overload and shut the pump down. Repeated thermal overloads may damage the pump and will create delays in sampling. 2.5 Maintenance and Precautions 1. Empty the hose of contaminated water before leaving the sampling location. Do not bring the hose back to the FEC if it contains purge water from a site. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 7 of 13 2. Field clean the pump prior to using at the next sampling location in accordance with the SESD Procedure for Field Equipment Cleaning and Decontamination (SESDPROC-205). 3. Do not run the generator without first checking the oil. 4. Do not put the pump in the trailer with the generator. 5. If the pump is equipped with a check valve or back flow preventer, periodically check this device to make sure that it is operating. This is a common place for debris or other material to accumulate and interfere with the proper operation of the device. If the water level in a well pulls down to below the pump inlet when operating with a check valve, the pump can airlock. The airlock can be relieved by surging the pump or pulling the pump from the well and draining the hose or tubing. 2.6 Trouble Shooting Generator running, no pump output 1. Loose wiring connection. 1. Check all connections. Repair as needed. (Generator off!!) 2. Cord unplugged at generator. 2. Plug pump back in. 3. Over voltage or Under voltage on controller display. 3. Adjust generator output/idle speed; allow generator more warm-up time. Use larger or shorter extension cord. 4. Pump out of water. 4. Lower pump into water. 5. Hose collapsed or kinked. 5. Un-kink hose. 6. Pump will not run or shuts down with thermal overload signal. Display indicates zero amps. 6. Use cooling shroud in wells larger than 2”. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 8 of 13 3 Geotech Portable Bladder Pump 3.1 General The Geotech Portable Bladder Pumps is primarily suitable for low-flow purging and sampling of wells as small as ¾” casing diameter. As deployed by SESD, the system uses the GeoControl Pro portable compressor/controller to power the downhole bladder and check valve mechanism. In operation, the pump is connected to drive tubing and sample tubing. On each pump cycle, the drive tube pressurizes a tubular bladder, compressing it inward and forcing well water through an upper check valve and up the discharge sample tubing to the surface. On release of pressure, the bladder relaxes, allowing water to enter the lower check valve from the well. The pumps are available in 1.5”, 0.85”, and 0.675” diameters. As of this revision, SESD owns a 0.85” pump, but these instructions apply to all pumps in the series. Bladder pump operation slows with increasing length of the drive tubing. As the volume of this tubing increases with length, the controller requires longer times to pressurize and depressurize the pump on each cycle. In wells with a tall water column, this effect can be minimized by the use of a drop tube. The pump is positioned submerged but near the top of the water column and the drop tube extends to the sampling interval. The drop tube conducts water from the sampling interval to the pump and the controller only has to pressurize enough drive tubing to reach the water surface. 3.2 Operation 1. Prepare the pump by connecting sample tubing to the central barb fitting and drive tubing to the outer barb fitting. The sample tubing should be new tubing suitable for the work, generally teflon. The drive tubing can be teflon or poly tubing and may be field cleaned between wells with the pump. If used, fasten a measured drop tube of new sample tubing to the lower barb on the pump and to a pickup screen. 2. Lower the pump into the well and locate it at the desired sampling interval. 3. Cut the tubing to suitable above-ground working lengths, allowing drive tubing to reach the controller and sample tubing to reach a bucket or flow- through cell. Connect the drive tubing to the controller. 4. Turn the controller on. As a starting point, the discharge time should allow the air line to pressurize to about 1 psi for each foot the water level is below ground surface. The fill time should initially be set to allow the air pressure to return to zero at the end of each cycle. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 9 of 13 5. If the pump does not discharge or is still discharging at the end of the pressure cycle, the discharge time can be increased. The fill time can be adjusted for maximum or desired flow. 3.3 Trouble Shooting Air in Sample Line 1. Damaged bladder or O- rings or bladder shifted 1. Inspect and replace. Limit air pressure to pump. 2. Outgassing of sample. 2. No action required. No sample line output 1. Pump above water 1. Check and adjust pump level. Reduce output to achieve stable drawdown. 2. Kinked drive or sample tubing 2. Check tubing and remedy. 3. Inadequate Air Pressure 3. Increase Discharge Time. 4. Silt in check valve. 4. Surge pump in well or remove from well and clean. Consider further well development with alternate pump. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 10 of 13 4 Geoprobe® Model MBP 470 Mechanical Bladder Pump 4.1 General The Geoprobe® Model MBP 470 Mechanical Bladder Pump can be used for purging small diameter temporary monitoring wells installed by direct push technology (DPT). These pumps represent one of only a few types of pumps that are capable of fitting inside the ID of the probe rod and that are also capable of pumping ground water whose water level is below the limit of suction. 4.2 Operations The Geoprobe® Model MBP 470 Mechanical Bladder Pump operates by manually or mechanically cycling a corrugated FEP Teflon® bladder contained within a small diameter pump body. The bladder is actuated by movement of a smaller diameter sample tubing within an outer tubing which positions and stabilizes the pump. As this pump is sensitive to silt, it is generally advantageous to develop the well first with an impulse pump before deploying the mechanical bladder pump for purging and sampling. The basic operation is as follows. 1. Following manufacturers guidelines, assemble the bladder pump with a new bladder. 2. Attach the pump to the larger diameter outer tubing by screwing it onto the tubing. The pump will cut shallow threads into the tubing. 3. Lower the pump into the well to the desired sampling interval. Note that it will be very difficult to reposition the pump later, often requiring recutting and redeploying the tubing system. 4. While holding the downhole tubing securely, cut off the tubing near the top of the well. 5. Using gravity as an aid, thread the sample tubing (generally teflon®) down into the outer tubing until it bottoms out against the pump. Cut off the sample tubing at a convenient length to reach a discharge bucket or flow-through cell. Remove the pump and the tubing assembly from the well. 6. Unscrew the pump from the outer tubing. Either push and shake the inner tubing from the top or cut off several inches of the outer tubing at the bottom until several inches of the inner tubing is exposed. 7. Unscrew the lower bladder adapter on the pump (refer to Geoprobe® Instruction Bulletin MK3022 or Technical Bulletin MK3013). Push the pump barbed fitting onto the sample tubing. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 11 of 13 8. Again screw the pump onto the outer tubing. Screw the lower bladder adapter back into the pump. This step may be facilitated by temporarily lowering the tubing assembly into the well upside down, uncoiling it onto a clean surface, or uncoiling it into a clean section of well casing assembled on the surface. 9. Again deploy the pump and tubing into the well. Secure the top of the outer tubing at the top of the well casing using either the Outer Tubing Grip of a manual actuator or the Outer Tubing Adapter of an electric actuator. 10. Using the Hand Grip Assembly of a manual actuator or the mechanism of an electric actuator, cycle the inner tubing up and down to actuate the pump bladder. The tubing should be gently tensioned at the bottom of the stroke and pulled upward several inches each stroke. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 12 of 13 5 Inertial Pump (Geoprobe® or Waterra®) 5.1 General The inertial pumps consist of a length of tubing with a check valve affixed to the lower end. It is a very simple device that is very effective at developing wells. As it is very difficult to produce low turbidity water with this pump due to the constant surging, it should generally not be used for sampling. The Geoprobe version of the pump can fit inside of the small diameter drive casing used for the installation of temporary screen- point wells. The Waterra version of the valve can use an attached surge block pressed onto the valve to develop 2” diameter wells. The inertial pump operates by manually or mechanically cycling the length of tubing and attached check valve up and down in the water column. The basic operation is as follows. 5.2 Operation 1. Affix a check valve to bottom of appropriate tubing by threading it onto the discharge tubing. The valve will cut shallow threads into the tubing. 2. Lower the valve and tubing to the bottom of the well. Cut the tubing to an appropriate length to reach a bucket or other discharge location. 3. Either by hand or by attaching the tubing to a mechanical actuator, rapidly move tubing and check valve up and down in the water column. 4 During each cycle, as the tubing is plunged downward in the water column, water will move upward through the check valve, past the ball check. On the upward stroke, the ball check will seat in the check valve, capturing water and moving it upward with the tubing. 5. For well development, cycle the valve in different portions of the screened interval. The inertial pump is also effective at vacuuming silt out of the bottom of the well. Uncontrolled When Printed Pump Operation SESDGUID-203-R4 Effective Date: March 14, 2018 Page 13 of 13 6 References SESD Operating Procedure for Field Equipment Cleaning and Decontamination, SESDPROC-205, Most Recent Version SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC, SESDPROC-206, Most Recent Version SESD Operating Procedure for Groundwater Sampling, SESDPROC-301, Most Recent Version US EPA. Analytical Support Branch Laboratory Operations and Quality Assurance Manual. Region 4 SESD, Athens, GA, Most Recent Version US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 SESD, Athens, GA, Most Recent Version 7 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the SESD Document Control Coordinator on the SESD local area network (LAN). History Effective Date SESDGUID-203-R4, Pump Operation, replaces SESDPROC-203-R3. General: Corrected any typographical, grammatical, and/or editorial errors. Additionally, the document was edited to reflect new Document Control Processes. The Operating Procedure was converted to a Guidance Document. March 14, 2018 SESDPROC-203-R3, Pump Operation, replaces SESDPROC-203-R2. September 12, 2013 SESDPROC-203-R2, Pump Operation, replaces SESDPROC-203-R1. November 6, 2009 SESDPROC-203-R1, Pump Operation, replaces SESDPROC-203-R0. November 1, 2007 SESDPROC-203-R0, Pump Operation, Original Issue February 05, 2007 Uncontrolled When Printed COPY SESD Operating Procedure Page 2 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the SESD Document Control Coordinator on the SESD local area network (LAN). History Effective Date SESDPROC-301-R4, Groundwater Sampling, replaces SESDPROC- 301-R3. General: Corrected any typographical, grammatical, and/or editorial errors. General: An extensive rewrite and reorganization of material. Stronger support of low-flow methods while maintaining cautious view of minimal/no purge methods. April 26, 2017 SESDPROC-301-R3, Groundwater Sampling, replaces SESDPROC-301-R2. March 6, 2013 SESDPROC-301-R2, Groundwater Sampling, replaces SESDPROC-301-R1. October 28, 2011 SESDPROC-301-R1, Groundwater Sampling, replaces SESDPROC- 301-R0. November 1, 2007 SESDPROC-301-R0, Groundwater Sampling, Original Issue February 05, 2007 COPY SESD Operating Procedure Page 3 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 TABLE OF CONTENTS 1 GENERAL INFORMATION .............................................................................................. 5 1.1 Purpose................................................................................................................................... 5 1.2 Scope/Application ................................................................................................................. 5 1.3 Documentation/Verification ................................................................................................. 5 1.4 References .............................................................................................................................. 5 1.5 General Precautions.............................................................................................................. 7 1.5.1 Safety ................................................................................................................................. 7 1.5.2 Procedural Precautions .................................................................................................... 8 2 SPECIAL SAMPLING CONSIDERATIONS ................................................................... 9 2.1 Volatile Organic Compounds (VOC) Analysis................................................................... 9 2.2 Special Precautions for Trace Contaminant Groundwater Sampling ............................. 9 2.3 Sample Handling and Preservation Requirements .......................................................... 10 2.4 Quality Control ................................................................................................................... 11 2.5 Records................................................................................................................................. 11 3 GROUNDWATER PURGING AND SAMPLING ......................................................... 12 3.1 Overview of Purging and Sampling Strategies ................................................................ 12 3.2 Purging ................................................................................................................................. 13 3.3 Parameter Stabilization Criteria ....................................................................................... 14 3.4 Multiple-Volume Purge ...................................................................................................... 16 3.4.1 Purge Volume Determination ......................................................................................... 16 3.4.2 Pumping Conditions ....................................................................................................... 18 3.4.3 Stability of Chemical Parameters ................................................................................... 18 3.4.4 Sample Collection ........................................................................................................... 18 3.5 Low-Flow Method ............................................................................................................... 18 3.5.1 Nomenclature .................................................................................................................. 19 3.5.2 Placement of Pump Tubing or Intake ............................................................................ 19 3.5.3 Conditions of Pumping ................................................................................................... 19 3.5.4 Stability of Chemical Parameters ................................................................................... 19 3.5.5 Sample Collection ........................................................................................................... 20 3.6 Minimum-Purge and No-Purge Sampling ........................................................................ 20 3.6.1 Minimum Purge Sampling ............................................................................................. 21 3.6.2 Passive Diffusion Bags ................................................................................................... 21 3.6.3 HydraSleevesTM ............................................................................................................. 21 3.6.4 Snap Samplers ................................................................................................................. 22 3.7 Equipment Considerations ................................................................................................. 22 3.7.1 Use of Peristaltic Pumps ................................................................................................. 22 3.7.2 Use of Submersible Centrifugal Pumps ......................................................................... 25 3.7.3 Use of Bailers .................................................................................................................. 25 3.7.4 Use of Bladder Pumps..................................................................................................... 26 3.7.5 Use of Inertial Pumps ..................................................................................................... 26 COPY SESD Operating Procedure Page 4 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.8 Wells With In-Place Plumbing .......................................................................................... 27 3.8.1 Continuously Running Pumps ....................................................................................... 27 3.8.2 Intermittently or Infrequently Running Pumps ............................................................. 28 3.9 Temporary Monitoring Wells ............................................................................................ 28 3.9.1 General Considerations .................................................................................................. 28 3.9.2 Development of Temporary Wells .................................................................................. 28 3.9.3 Decommissioning of Temporary Wells .......................................................................... 29 3.9.4 Other Considerations for Direct-Push Groundwater Sampling ................................... 30 3.10 Wells Purged to Dryness .................................................................................................... 30 4 ADDITIONAL PURGING AND SAMPLING CONSIDERATIONS ........................... 31 4.1 Field Care of Purging Equipment ..................................................................................... 31 4.2 Investigation Derived Waste .............................................................................................. 31 4.3 Sample Preservation ........................................................................................................... 31 4.4 Special Sample Collection Procedures .............................................................................. 31 4.4.1 Trace Organic Compounds and Metals ......................................................................... 31 4.4.2 Order of Sampling with Respect to Analytes.................................................................. 32 4.5 Filtering ................................................................................................................................ 32 4.6 Bacterial Sampling .............................................................................................................. 33 4.7 Specific Sampling Equipment Quality Assurance Techniques ....................................... 34 4.8 Auxiliary Data Collection ................................................................................................... 34 4.9 Well Development ............................................................................................................... 34 COPY SESD Operating Procedure Page 5 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 1 General Information 1.1 Purpose This document describes general and specific procedures, methods and considerations to be used and observed when collecting groundwater samples for field screening or laboratory analysis. 1.2 Scope/Application The procedures contained in this document are to be used by field personnel when collecting and handling groundwater samples in the field. On the occasion that SESD field personnel determine that any of the procedures described are either inappropriate, inadequate or impractical and that another procedure must be used to obtain a groundwater sample, the variant procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. 1.3 Documentation/Verification This procedure was prepared by persons deemed technically competent by SESD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the SESD Local Area Network (LAN). The Document Control Coordinator (DCC) is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance. 1.4 References International Air Transport Authority (IATA). Dangerous Goods Regulations, Most Recent Version Interstate Technology & Regulatory Council, Technology Overview of Passive Sampler Technologies, Prepared by The Interstate Technology & Regulatory Council Diffusion Sampler Team, March 2006. Nielsen, David. Practical Handbook of Environmental Site Characterization and Ground-Water Monitoring. 2nd ed. Boca Raton, FL: Taylor&Francis, 2006. Print. Puls, Robert W., and Michael J. Barcelona. 1989. Filtration of Ground Water Samples for Metals Analysis. Hazardous Waste and Hazardous Materials 6(4), pp.385-393. COPY SESD Operating Procedure Page 6 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 Puls, Robert W., Don A. Clark, and Bert Bledsoe. 1992. Metals in Ground Water: Sampling Artifacts and Reproducibility. Hazardous Waste and Hazardous Materials 9(2), pp. 149-162. SESD Guidance Document, Design and Installation of Monitoring Wells, SESDGUID- 001, Most Recent Version SESD Operating Procedure for Control of Records, SESDPROC-002, Most Recent Version SESD Operating Procedure for Sample and Evidence Management, SESDPROC-005, Most Recent Version SESD Operating Procedure for Logbooks, SESDPROC-010, Most Recent Version SESD Operating Procedure for Field Sampling Quality Control, SESDPROC-011, Most Recent Version SESD Operating Procedure for Field pH Measurement, SESDPROC-100, Most Recent Version SESD Operating Procedure for Field Specific Conductance Measurement, SESDPROC- 101, Most Recent Version SESD Operating Procedure for Field Temperature Measurement, SESDPROC-102, Most Recent Version SESD Operating Procedure for Field Turbidity Measurement, SESDPROC-103, Most Recent Version SESD Operating Procedure for Groundwater Level and Well Depth Measurement, SESDPROC-105, Most Recent Version SESD Operating Procedure for Management of Investigation Derived Waste, SESDROC- 202, Most Recent Version SESD Operating Procedure for Pump Operation, SESDPROC-203, Most Recent Version SESD Operating Procedure for Field Equipment Cleaning and Decontamination, SESDPROC-205, Most Recent Version SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC, SESDPROC-206, Most Recent Version COPY SESD Operating Procedure Page 7 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 SESD Operating Procedure for Potable Water Supply Sampling, SESDPROC-305, Most Recent Version United States Environmental Protection Agency (US EPA). 1975. Handbook for Evaluating Water Bacteriological Laboratories. Office of Research and Development (ORD), Municipal Environmental Research Laboratory, Cincinnati, Ohio. US EPA. 1977. Sampling for Organic Chemicals and Microorganisms in the Subsurface. EPA-600/2-77/176. US EPA. 1978. Microbiological Methods for Monitoring the Environment, Water and Wastes. ORD, Municipal Environmental Research Laboratory, Cincinnati, Ohio. US EPA. 1981. "Final Regulation Package for Compliance with DOT Regulations in the Shipment of Environmental Laboratory Samples," Memo from David Weitzman, Work Group Chairman, Office of Occupational Health and Safety (PM-273), April 13, 1981. US EPA. 1995. Ground Water Sampling - A Workshop Summary. Proceedings from the Dallas, Texas November 30 – December 2, 1993 Workshop. ORD, Robert S. Kerr Environmental Research Laboratory. EPA/600/R-94/205, January 1995. US EPA 1996. Ground Water Issue. Low-Flow (Minimal Drawdown) Ground-Water Sampling Procedures. ORD, Robert W. Puls and Micael Barcelona. EPA/540/S-95/504, April 1996 US EPA. Analytical Services Branch Laboratory Operations and Quality Assurance Manual. Region 4 SESD, Athens, GA, Most Recent Version US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 SESD, Athens, GA, Most Recent Version Varljen, M., Barcelona, M., Obereiner, J., & Kaminski, D. (2006). Numerical simulations to assess the monitoring zone achieved during low-flow purging and sampling. Ground Water Monitoring and Remediation, 26(1), 44-52. 1.5 General Precautions 1.5.1 Safety Proper safety precautions must be observed when collecting groundwater samples. Refer to the SESD Safety, Health and Environmental Management Program (SHEMP) Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASP) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. The reader should address chemicals that pose specific toxicity or safety concerns COPY SESD Operating Procedure Page 8 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 and follow any other relevant requirements, as appropriate. 1.5.2 Procedural Precautions The following precautions should be considered when collecting groundwater samples. • Special care must be taken not to contaminate samples. This includes storing samples in a secure location to preclude conditions which could alter the properties of the sample. Samples shall be custody sealed during long-term storage or shipment. • Always sample from the anticipated cleanest, i.e., least contaminated location, to the most contaminated location. This minimizes the opportunity for cross-contamination to occur during sampling. • Collected samples must remain in the custody of the sampler or sample custodian until the samples are relinquished to another party. • If samples are transported by the sampler, they will remain under his/her custody or be secured until they are relinquished. • Chain-of-custody documents shall be filled out and remain with the samples until custody is relinquished. • Shipped samples shall conform to all U.S. Department of Transportation (DOT) rules of shipment found in Title 49 of the Code of Federal Regulations (49 CFR parts 171 to 179), and/or International Air Transportation Association (IATA) hazardous materials shipping requirements found in the current edition of IATA’s Dangerous Goods Regulations. • Documentation of field sampling is done legibly, completely, and neatly in a bound logbook. COPY SESD Operating Procedure Page 9 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 2 Special Sampling Considerations 2.1 Volatile Organic Compounds (VOC) Analysis Groundwater samples for VOC analysis must be collected in 40 ml glass vials with Teflon® septa. The vial may be either pre-preserved with concentrated hydrochloric acid or they may be unpreserved. Preserved samples have a two-week holding time, whereas unpreserved samples have only a seven-day holding time. In the majority of cases, the preserved vials are used to take advantage of the extended holding time. In some situations, however, it may be necessary to use the unpreserved vials. For example, if the groundwater has a high amount of dissolved limestone, i.e., is highly calcareous, there will likely be an effervescent reaction between the hydrochloric acid and the water, producing large numbers of fine bubbles and rendering the sample unacceptable. In this case, unpreserved vials should be used and arrangements confirmed with the laboratory to ensure that they can accept the unpreserved vials and meet the shorter sample holding times. The samples should be collected with as little agitation or disturbance as possible. The vial should be filled so that there is a meniscus at the top of the vial and no bubbles or headspace should be present in the vial after it is capped. After the cap is securely tightened, the vial should be inverted and tapped on the palm or knuckle to check if any undetected bubbles are dislodged. If a bubble or bubbles are present, the vial should be topped off using a minimal amount of sample to re-establish the meniscus. Care should be taken not to flush any preservative out of the vial during topping off. If, after topping off and capping the vial, bubbles are still present, a new vial should be obtained and the sample re-collected. While the 8260 method allows for bubbles up to 6 mm at the time of analysis, dissolved or entrained gases can coalesce during shipment. Collecting VOC vials absent of bubbles is generally feasible and is a reasonable precaution. 2.2 Special Precautions for Trace Contaminant Groundwater Sampling • Sampling equipment must be constructed of Teflon® or stainless steel materials. Bailers and pumps should be of Teflon® and stainless steel construction throughout. • New Teflon® tubing should be used at each well, although tubing dedicated to a particular well may be reused, either after decontamination or storage in the well between sampling events. Caution is appropriate in reusing tubing where early sampling events report high concentrations of contaminants. • A clean pair of new, non-powdered, disposable gloves will be worn each time a different location is sampled and the gloves should be donned immediately prior to sampling. The gloves should not come in contact with the media being sampled and should be changed any time during sample collection when their cleanliness is compromised. • Sample containers for samples suspected of containing high concentrations of contaminants shall be stored separately. COPY SESD Operating Procedure Page 10 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 • Sample collection activities shall proceed progressively from the least suspected contaminated area to the most suspected contaminated area if purging and sampling devices are to be reused. Samples of waste or highly contaminated media must not be placed in the same cooler as environmental (i.e., containing low contaminant levels) or background samples. • If possible, one member of the field sampling team should take all the notes and photographs, fill out tags, etc., while the other members collect the samples. • Clean plastic sheeting will be placed on the ground at each sample location to prevent or minimize contaminating sampling equipment by accidental contact with the ground surface. • Samplers must use new, verified certified-clean disposable or non-disposable equipment cleaned according to procedures contained in SESD Operating Procedure for Field Equipment Cleaning and Decontamination (SESDPROC-205) or SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC (SESDPROC-206) for collection of samples for trace metals or organic compound analyses. 2.3 Sample Handling and Preservation Requirements 1. Groundwater samples will typically be collected from the discharge line of a pump or from a bailer. Efforts should be made to reduce the flow from either the pump discharge line or the bailer during sample collection to minimize sample agitation. 2. During sample collection, make sure that the pump discharge line or the bailer does not contact the sample container. 3. Place the sample into appropriate, labeled containers. Samples collected for VOC, and alkalinity analysis must be collected without headspace. All other sample containers must be filled with an allowance for ullage. 4. All samples requiring preservation must be preserved as soon as practically possible, ideally immediately at the time of sample collection. If pre-preserved VOC vials are used, these will be preserved with concentrated hydrochloric acid by Analytical Services Branch (ASB) personnel prior to departure for the field investigation. For all other chemical preservatives, SESD will use the appropriate chemical preservative generally stored in an individual single-use vial as described in the SESD Operating Procedure for Field Sampling Quality Control (SESDPROC-011). The adequacy of sample preservation will be checked after the addition of the preservative for all samples except for the samples collected for VOC analysis. If additional preservative is needed, it should be added to achieve adequate preservation. Preservation requirements for groundwater samples are found in the USEPA Region 4 Analytical Services Branch Laboratory Operations and Quality Assurance Manual (ASBLOQAM), most recent version. COPY SESD Operating Procedure Page 11 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 5. Sample containers should be placed in an ice-filled cooler as soon as possible after filling. Ice in coolers should be in bags with minimal pooled water and the cooler should be periodically checked and replenished to maintain sample storage temperature. 2.4 Quality Control Equipment blanks should be collected if equipment is field cleaned and re-used on-site or if necessary to document that low-level contaminants were not introduced by pumps, bailers, tubing, or other sampling equipment. Where appropriate, a background sample upgradient of all known influences or a control sample upgradient of site influences may be indicated. Background and control samples should be collected as close to the sampled area as possible and from the same water- bearing formation as the site samples. 2.5 Records Information generated or obtained by SESD personnel will be organized and accounted for in accordance with SESD records management procedures found in SESD Operating Procedure for Control of Records, SESDPROC-002. Field notes, recorded in a bound field logbook, will be generated, as well as chain-of-custody documentation in accordance with SESD Operating Procedure for Logbooks, SESDPROC-010 and SESD Procedure for Sample and Evidence Management, SESDPROC-005. COPY SESD Operating Procedure Page 12 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3 Groundwater Purging and Sampling 3.1 Overview of Purging and Sampling Strategies Purging is the process of removing stagnant water from a well, immediately prior to sampling, causing its replacement by groundwater from the adjacent formation that is representative of aquifer conditions. Sampling is the process of obtaining, containerizing, and preserving (when required) a ground water sample after the purging process is complete. There are several approaches to well purging and sampling that may be appropriate in various circumstances or for various combinations of available equipment. They are briefly summarized below and in Table 1, Purge and Sample Strategies with Equipment Considerations. The Multiple-Volume Purge method involves removing a minimum of three well volumes of water from the top of the water column and then sampling when the well has achieved stability of water quality parameters and adequately low turbidity. This is a traditional method and consistent results are generally obtained with samplers of varying skill. A drawback is that large volumes of purge water may be produced for large diameter or deep wells. The Low-Flow method involves purging the well at a relatively low flow rate that minimizes drawdown, with the pump or tubing inlet located within the screened interval of the well. The well is sampled when water quality parameters are stable, adequately low turbidity is achieved, and the water level has achieved a stable drawdown (an unchanging water level). This method is often faster than Multiple-Volume Purge and generates less purge water. The method requires more skill and judgment on the part of the samplers. The Multiple-Volume Purge method and the Low-Flow method can be considered equivalent for conventionally screened and filter-packed wells in that they both sample a flow-weighted average of water entering the well during pumping. However, other variables can result in differences between results with the two methods. In repeat sampling events, the sampling design should not change from one method to the other without appropriate cause. The transition should be noted in the report. Minimum-Purge and No-Purge methods are based on the assumption that water within the screened interval of the well is at equilibrium with the water in the surrounding aquifer. This assumption should be carefully considered in the use of these methods and various cautions are discussed in sections below. The minimal-purge and no-purge methods are most useful for long-term monitoring and are generally inappropriate for the early stages of investigation. In some cases the methods might be used to gather screening-level data from wells that are too large to practically purge or have other sampling complications. COPY SESD Operating Procedure Page 13 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 The Minimum-Purge and No-Purge methods collect water in the vicinity of the device under near-static conditions and are not equivalent to the multiple-volume purge and Low-Flow methods. Stratification of horizontal flow or vertical flow conditions within the well can result in non-intuitive and deceptive results. A comparison study should be conducted before transitioning a sampling program to the minimal-purge or no-purge methods. 3.2 Purging Wells are purged to eliminate stagnant water residing in the casing and/or screen that has undergone geochemical changes or loss of VOCs. At the conclusion of purging, the desired flow-weighted average of water entering the well under pumping conditions will be available for sampling. Turbidity is often elevated during purging by the disturbance of formation materials at the borehole walls. As many contaminants (metals and many organics) will sorb to the formation particles, a sample including these particles will not represent the dissolved concentrations of the contaminants. Thus, a secondary goal of purging is to reduce the turbidity to the point that the sample will represent the dissolved concentration of contaminants. In order to determine when a well has been adequately purged, field investigators should monitor, at a minimum, the pH, specific conductance and turbidity of the groundwater removed and the volume of water removed during purging. The measurements should be recorded in a purge table in the field logbook that includes the start time of purging, the parameter measurements at intervals during purging, estimated pumped volumes, depths to water for Low-Flow sampling, and any notes of unusual conditions. A typical purge table used for Low-Flow sampling is reproduced below. COPY SESD Operating Procedure Page 14 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.3 Parameter Stabilization Criteria With respect to the ground water chemistry, an adequate purge is achieved when the pH and specific conductance of the ground water have stabilized and the turbidity has either stabilized or is below 10 Nephelometric Turbidity Units (NTUs) (twice the Secondary Drinking Water Standard of 5 NTUs). Stabilization occurs when, for at least three consecutive measurements, the pH remains constant within 0.1 Standard Unit (SU) and specific conductance varies no more than 5 percent. Other parameters, such as dissolved oxygen (DO) or oxidation-reduction potential (ORP), may also be used as a purge adequacy parameter. Normal stability goals for DO are 0.2 mg/L or 10% change in saturation, whichever is greater. DO and ORP measurements must be conducted using either a flow-through cell or an over-topping cell to minimize oxygenation of the sample during measurement. A reasonable ORP stability goal is a range of 20 mV, although ORP is rarely at equilibrium in environmental media and often will not demonstrate enough stability to be used as a purge stabilization parameter. Determining the frequency of measurements has generally been left to ‘Best Professional Judgement’. Care is in order, as measurements recorded at frequent intervals with low flow rates can falsely indicate stability of parameters. Several measurements should be made early in the well purge to establish the direction and magnitude of trends, which can then inform the stability decision. Stability parameters should either be not trending, or approaching an asymptote, when a stability determination is made. As a matter of practice, parameter measurements are generally made at 5-10 minute intervals. Because the measured groundwater temperature during purging is subject to changes related to surface ambient conditions and pumping rates, its usefulness is subject to question for the purpose of determining parameter stability. As such, it has been removed from SESD’s list of parameters used for stability determination. Even though temperature is not used to determine stability, it is still advisable to record the temperature of purge water as it is often used in the interpretation of other parameters. Information on conducting the stability parameter measurements is available in the SESD Operating Procedures for Field pH Measurement (SESDPROC-100), Field Specific Conductance Measurement (SESDPROC-101), Field Temperature Measurement (SESDPROC-102), Field Turbidity Measurement (SESDPROC-103), Field Measurement of Dissolved Oxygen (SESDPROC-106) and Field Measurement of Oxidation-Reduction Potential (SESDPROC-113). COPY SESD Operating Procedure Page 15 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 COPY SESD Operating Procedure Page 16 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.4 Multiple-Volume Purge In the traditional Multiple-Volume Purge method, water is removed from the top of the water column, causing water to enter the screen and flush stagnant casing water upward to be subsequently removed. In recognition of the mixing of fresh and stagnant water in the casing section, a minimum of three well volumes is removed, at which time purging can be terminated upon parameter stabilization. Wells can be assumed to be adequately purged when five well volumes have been removed, although further purging may be conducted to meet specific goals, such as further reduction of turbidity. 3.4.1 Purge Volume Determination Prior to initiating the purge, the amount of water standing in the water column (water inside the well riser and screen) should be determined The diameter of the well is determined and the water level and total depth of the well measured and recorded prior to inserting a pump or tubing into the well. The water level is subtracted from the total depth, providing the length of the water column. Specific methodology for obtaining these measurements is found in SESD Operating Procedure for Groundwater Level and Well Depth Measurement (SESDPROC-105). Once this information is obtained, the volume of water to be purged can be determined using one of several methods. The well volume can be calculated using the equation: V = 0.041 d2h Where: h = length of water column in feet d = diameter of well in inches V = one well volume in gallons Alternatively, the volume of standing water in the well and the volume of three water columns may be determined using a casing volume per foot factor for the appropriate diameter well, such as Table 2 Well Casing Diameter Volume Factors. The water column length is multiplied by the appropriate factor in the Table 2 to determine the single well volume, three well volumes, or five well volumes for the well in question. Other acceptable methods include the use of nomographs or other equations or formulae. COPY SESD Operating Procedure Page 17 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 TABLE 2, WELL CASING DIAMETER VOLUME FACTORS Reference Minimum purge Maximum purge* 1 Well Volume (gallons/ft) 3 Well Volumes (gallons/ft) 5 Well Volumes (gallons/ft) Well Casing Diameter (in) 0.5 0.01 0.03 0.05 0.75 0.02 0.07 0.11 1 0.04 0.12 0.20 2 0.16 0.49 0.82 3 0.37 1.1 1.8 4 0.65 2.0 3.3 5 1.0 3.1 5.1 6 1.5 4.4 7.3 7 2.0 6.0 10.0 8 2.6 7.8 13.1 9 3.3 9.9 16.5 10 4.1 12.2 20.4 11 4.9 14.8 24.7 12 5.9 17.6 29.4 13 6.9 20.7 34.5 14 8.0 24.0 40.0 15 9.2 27.5 45.9 16 10.4 31.3 52.2 18 13.2 39.7 66.1 24 23.5 70.5 118 36 52.9 159 264 48 94.0 282 470 * See text for discussion on terminating purge at five well volumes An adequate purge is normally achieved when three to five well volumes have been removed. The field notes should reflect the single well volume calculations or determinations, according to one of the above methods, and a reference to the appropriate multiplication of that volume, i.e., a minimum three well volumes, clearly identified as an initial purge volume goal. COPY SESD Operating Procedure Page 18 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.4.2 Pumping Conditions The pump or tubing inlet should be located at the top of the water column. If the pump is placed deep into the water column, the water above the pump may not be removed, and the subsequent samples, particularly if collected with a bailer, may not be representative of the aquifer conditions. If the recovery rate of the well is faster than the pump rate and no observable draw down occurs, the pump should be raised until the intake is as close as possible to the top of the water column for the duration of purging. If the pump rate ex- ceeds the recovery rate of the well, the pump or tubing will have to be lowered to accommodate the drawdown. 3.4.3 Stability of Chemical Parameters In the multiple-volume purge method, a stability determination may be made after three well volumes have been removed. If the chemical parameters have not stabilized according to the above criteria, additional well volumes (up to a total of five well volumes) should be removed. If the parameters have not stabilized after the removal of five well volumes, it is at the discretion of the project leader whether or not to collect a sample or to continue purging. If, after five well volumes, pH and conductivity have stabilized and the turbidity is still decreasing and approaching an acceptable level, additional purging should be considered to obtain the best sample possible. 3.4.4 Sample Collection There are several means by which sampling can proceed after adequate volume has been purged and water quality parameters have stabilized. If a submersible pump and tubing are of suitable material and cleanliness for sample collection, sampling can proceed immediately by directly filling bottles from the tubing outlet. Commonly with the multiple-volume purge method, the pump is set up and cleaned in a manner suitable only for purging. In these cases, the pump is stopped and removed from the well and sampling proceeds with a bailer per the procedure described in Section 3.6.3. The pump should have a check valve to prevent water in the pump tubing from discharging back into the well when the pump is stopped. If a peristaltic pump is used, sampling can proceed as described in Section 3.6.1. 3.5 Low-Flow Method This method involves placing the pump or tubing inlet within the screened interval of the well and purging at a low enough rate to achieve stable drawdown and minimal depression of the water level. The well is sampled without interruption after field parameters are stable and low turbidity is achieved. In general, only water in the screened interval of the well is pumped and the stagnant water in the well casing above the screen is not removed. Wells can generally be sampled in less time with less purge volume than with the multi-volume purge method. More attention is required in the assessment of stability criteria than the multi-volume method. COPY SESD Operating Procedure Page 19 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.5.1 Nomenclature A variety of terminology has been used to describe this method by SESD and others, including: ‘low flow’, ‘low-flow/low-volume’, ‘tubing-in-screen method’, ‘low flow/ minimal drawdown’, and ‘micropurge’. The current preferred SESD terminology for this method is ‘Low-Flow’. As the term ‘micropurge’ is sometimes used to refer to minimal-purge methods and has been trademarked by a vendor, the use of ‘micropurge’ to describe the Low-Flow method generally introduces ambiguity and confusion and thus the use of the term is discouraged. 3.5.2 Placement of Pump Tubing or Intake The inlet of the pump tubing or intake of the submersible pump is placed in the approximate mid-portion of the screened interval of the well. While it is often thought that particular aquifer zones can be targeted by specific pump or intake placement, for conventionally constructed screened and filter-packed monitoring wells the zone monitored is only weakly dependent on the intake placement (Varljen, Barcelona, Obereiner & Kaminski, 2006). The pump or tubing can be placed by carefully lowering them to the bottom of the well and then withdrawing half of the screen length, plus the length of any sump sections at the bottom of the well. A drawback of this approach is that it may stir up sediment at the well bottom. An alternate approach is to lower the pump or tubing a measured distance to place it at mid-screen without touching the bottom of the well. In the case of pumps, special care should be used in lowering them slowly, especially in the screened interval, to prevent elevating turbidity needlessly by the surging action of the pump. 3.5.3 Conditions of Pumping Prior to initiation of pumping, a properly decontaminated well sounder should be lowered into the well to measure the water level prior to and during the purging process. Ideally, there should be only a slight and stable drawdown of the water column after pumping begins. In some cases, it will be necessary for the well to drawdown a considerable distance (10 ft or more in extreme cases) to maintain a minimal usable pumping rate for sampling (100-200 ml/min). Excessive pump rates and drawdown can result in increased turbidity, or aeration of the sample if the screen is exposed. Stable drawdown is an essential condition of the Low-Flow method. If the stable drawdown condition cannot be met, then one of the other methods should be employed. 3.5.4 Stability of Chemical Parameters As with the Multiple-Volume Purging method described, it is important that all chemical parameters be stable prior to sampling. It is common for wells to require the removal of one of more screened-interval volumes (~2 gal for a 10 ft screen in a 2” dia. well) to achieve stability. Although it is possible for wells to achieve stability with lower purge volumes, the sampler should exercise caution in making an early stability determination. COPY SESD Operating Procedure Page 20 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.5.5 Sample Collection Low-Flow sampling is implemented using a pump and tubing suitable for sampling. After making the determination of parameter stability with stable drawdown, sampling can proceed immediately. Where submersible or bladder pumps are used, sampling can proceed by directly filling bottles from the tubing outlet. Where peristaltic pumps are used, sampling can proceed per the procedure described in Section 3.6.3. 3.6 Minimum-Purge and No-Purge Sampling The Minimum-Purge and No-Purge sampling methods are employed when it is necessary to keep purge volumes to an absolute minimum, where it is desirable to reduce long-term monitoring costs, or where large wells or other limitations prevent well purging. The underlying assumption when employing these methods is that the water within the well screen is equilibrated with the groundwater in the associated formation. This assumption should be demonstrated prior to use of these methods or the results suitably qualified. These methods are generally impractical for SESD to implement because of the common lack of hydrogeological information in early investigative phases and the necessity with some methods that the samplers be pre-deployed to allow equilibration. Vertical flow conditions and stratification of the water column have also been known to result in deceptive and non-intuitive analytical results. The use of these methods in the early phases of investigation can easily result in misinterpretation of site conditions and plume boundaries. Particular caution is in order in the use of these methods when any of the following conditions exist: • Low hydraulic conductivity (K<10-5 cm/sec) • Low groundwater surface gradients • Fractured bedrock • Wells with long screened intervals • Wells screened in materials of varying hydraulic conductivities If it is desired to transition a long-term monitoring program to Minimum-Purge or No-Purge sampling, a pilot study should be conducted where the Minimum-Purge or No-Purge sample results are compared to the conventional methods in use. Multiple samplers may be deployed in the screened interval to help establish appropriate monitoring intervals. These methods are in common use and for the purposes of the SESD quality system they can be considered standard, but unaccredited, procedures. Several Minimum-Purge or No-Purge procedures that might be employed are shown below. It is not the intention to recommend particular equipment or vendors, and other equipment that can accomplish the same goals may be suitable. COPY SESD Operating Procedure Page 21 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3.6.1 Minimum Purge Sampling The pump or tubing inlet is deployed in the screened interval. A volume of water equal to the internal pump and tubing volume is pumped to flush the equipment. Sampling then proceeds immediately. While superficially similar to Low-Flow sampling, the results obtained in this method will be sensitive to the vertical pump or tubing inlet placement and are subject to the limitations described above. 3.6.2 Passive Diffusion Bags The no-purge Passive Diffusion Bag (PDB) typically consists of a sealed low-density polyethylene (LDPE) bag containing deionized water. They are deployed in the screened interval of a well and allowed to equilibrate, commonly for two weeks, prior to retrieval and decanting of the water into sample containers. Many volatile organic compounds will reach equilibrium across the LDPE material, including BTEX compounds and many chlorinated solvents. Compounds showing poor equilibration across LDPE include acetone, MTBE, MIBK, and styrene. PDBs have been constructed of other materials for sampling other analytes, but the vast majority of PDB samplers are of the LDPE material. Various vendors and the Interstate Technology and Regulatory Council (ITRC) can provide additional information on these devices. 3.6.3 HydraSleevesTM HydraSleeevesTM are no-purge grab sampling devices consisting of a closed-bottom sleeve of low-density polyethylene with a reed valve at the top. They are deployed in a collapsed state to the desired interval and fill themselves through the reed valve when pulled upward through the sampling interval. The following is a summary of their operation: Sampler placement – A reusable weight is attached to the bottom of the sampler or the sampler is clipped to a weighted line. The HydraSleeveTM is lowered on the weighted line and placed with the top of the sampler at the bottom of the desired sampling interval. In-situ water pressure keeps the reed valve closed, preventing water from entering the sampler. The well is allowed to return to equilibrium. Sample collection - The reed valve opens to allow filling when the sampler is moved upward faster than 1 foot per second, either in one continuous upward pull or by cycling the sampler up and down to sample a shorter interval. There is no change in water level and only minimal agitation during collection. Sample retrieval - When the flexible sleeve is full, the reed valve closes and the sampler can be recovered without entry of extraneous overlying fluids. Samples are removed by puncturing the sleeve with the pointed discharge tube and draining the contents into containers for sampling or field parameter measurements. COPY SESD Operating Procedure Page 22 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 Because the HydraSleeveTM is retrieved before equilibration can occur and they are constructed of non-Teflon® materials, there may be issues with sorbtion of contaminants in the use of this sampler. 3.6.4 Snap Samplers The Snap Sampler is a patented no-purge groundwater sampling device that employs a double-end-opening bottle with “Snap” sealing end caps. The dedicated, device is deployed at the desired position in the screened interval with up to six Snap Samplers and six individual sampling bottles. The device is allowed to equilibrate in the screened interval and retrieved between 3 and 14 days after deployment. Longer deployments are possible to accommodate sampling schedules. To operate, Snap Samplers are loaded with Snap Sampler bottles and the "Snap" caps are set into an open position. Samplers are deployed downhole with an attachment/trigger line and left to equilibrate downhole. To collect samples, the Snap Sampler bottles seal under the water surface by pulling a mechanical trigger line, or using an electric or pneumatic trigger system. The trigger releases Teflon® "Snap Caps" that seal the double-ended bottles. The end caps are designed to seal the water sample within the bottles with no headspace vapor. After the closed vial is retrieved from the well, the bottles are prepared with standard septa screw caps and labeled for laboratory submittal. The manufacturer of the Snap Sampler provides considerable additional information on the validation and use of the device. 3.7 Equipment Considerations Equipment choices are dictated by the purging and sampling method used, the depth to water, the quantity of water to be pumped, and quality considerations. The advantages and disadvantages of various commonly used pumps are discussed in the sections below and summarized in Table 1, Purge and Sample Strategies with Equipment Considerations. Additional information on the use of individual pumps is available in SESD Operating Procedure for Pump Operation, SESDPROC-203. 3.7.1 Use of Peristaltic Pumps Peristaltic pumps are simple, inexpensive, and reliable equipment for purging and sampling where the limit of suction is not exceeded (approximately 25-30 vertical feet from the groundwater surface to the pump). When used for sampling, they should be equipped with new Teflon® tubing for each well. The flexible peristaltic pump-head tubing should also be changed between wells. Samples for organic analyses cannot be exposed to the flexible peristaltic pump-head tubing, both due to the risk that the tubing would sorb contaminants and the propensity of this tubing to contribute organic compounds to the sample. Samples can be collected without contact with the pump-head tubing by the use of vacuum transfer caps for COPY SESD Operating Procedure Page 23 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 analyses requiring 1 liter glass containers and the use of the ‘soda-straw’ method for the filling of VOC vials. The sample containers for the more turbidity-sensitive analyses are filled first, as filling the VOC vials (and to a lesser extent the glass bottles) may disturb the well and increase turbidity. The most appropriate order of sampling with a peristaltic pump is generally to fill poly containers for metals and classical analyses, followed by glass bottles for SVOCs and associated analyses, and finally to fill 40 ml VOC vials. The following step-by-step procedure assumes that the pump has been set up per SESD Operating Procedure for Pump Operation (SESDPROC-203) and that containers for a typical full suite of analyses will be filled. The procedure is suitable for use with either multi-volume Purge and Low-Flow methods with minor differences in the collection of VOCs: 1. Deploy the lower end of the tubing to the desired point in the well. This would be the top-of-water for the multi-volume purge method or to the mid-screen for the Low-Flow method. Connect the well tubing to the flexible pump-head tubing and connect a short piece of tubing from the pump-head tubing to a measuring bucket. 2. Turn on the pump and establish a suitable pumping rate. For the multi-volume purge method, the rate will generally be a relatively fast rate that the well will sustain without elevating turbidity. For the low-flow method the pump rate is established at a slower rate to maintain a minimal and stable drawdown level. 3. Proceed with the measurement of water quality parameters and adjust the pump rate as needed to achieve low turbidity and stable drawdown. 4. When the well purge has been determined to be sufficient, fill containers for metals and classical analyses directly from the pump outlet. There is no need to interrupt pumping. The tubing should be held at the opening of the container and should not touch the container during filling. Protect caps from dust and debris during filling. 5. After filling the containers for metals and classical analyses stop the pump. Make sure that the tubing leading into the well is secured against movement during the following operations. 6. Create a crimp in the well tubing approximately one foot from the pump and grasp the crimped tubing in one hand. It is generally most effective to create a double ‘Z’ crimp. 7. Cut the sample tubing between the crimp and the pump. The tightly-held crimped tubing should keep water from running back into the well. In lieu of COPY SESD Operating Procedure Page 24 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 cutting the tubing, the well tubing can be disconnected from the pump and a short piece of tubing connected in its place. 8. Insert both free ends of the tubing into the ferrule-nut fittings of a pre-cleaned Teflon® transfer cap assembly and tighten the nuts. Attach the transfer cap assembly to the first glass container for semi-volatile analysis and securely tighten the threaded ring. 9. Turn the pump on. Very slowly release the ‘Z’ crimp in the sample tubing. As vacuum builds up in the sample container, water should begin to move up the sample tubing instead of back into the well. If after several minutes water has not begun moving up the tubing, check the tightness of fittings and the attachment of the cap to the bottle. Allowing water to rush back down the tubing from the ‘Z’ crimp can surge the well and elevate turbidity. 10. Fill the container to about halfway between the shoulder and the neck. Crimp the well tubing. Move the transfer cap to any additional bottles and repeat the filling process. 11. When finished filling bottles with the transfer cap, again crimp the tubing. Remove the well tubing from the transfer cap and reattach it to the pump. Slowly run the pump and release the crimp until water is approaching the flexible peristaltic tubing. 12. Make a kink or otherwise mark the tubing at the top of the casing in case the tubing needs to be reinserted for additional sample volume. Slowly remove the tubing from the well and coil it in one hand in loose coils. With the top end of the tubing blocked, water is retained in the tubing as it is withdrawn, much as in a capped soda straw, hence the name for this method. 13. Remove the top from a 40 ml VOC vial and position the end of the sample tubing near the top of the vial. Reverse the pump direction and turn the speed knob to its slowest position. Turn on the pump and slowly increase speed until water slowly fills the vial. Fill the vial with a slow laminar flow that does not agitate the water in the vial or entrain bubbles. Continue to fill the vial until a convex meniscus forms on the top of the vial and turn off the pump. 14. Carefully screw the septum-lid to the vial and fasten firmly. Invert the vial and tap on your knuckles to check for bubbles. Carefully add additional volume to the vial if necessary. Small bubbles are undesirable but may be unavoidable with some media, especially when using pre-preserved vials. 15. Repeat the filling process for additional vials. Avoid partially filling vials as the available water in the tubing is used. If more volume is required than that contained in the tubing, purge the remaining water from the tubing and reinsert COPY SESD Operating Procedure Page 25 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 the tubing in the well to the level marked previously. Run the pump to refill the tubing. If performing Low-Flow sampling, run additional volume through the pump to purge any water that may have been collected from the stagnant water column. 16. Fill additional vials as needed. Be sure that any water that has contacted the flexible peristaltic tubing is not pumped into a vial. 3.7.2 Use of Submersible Centrifugal Pumps Submersible centrifugal pumps are used in wells of 2” diameter and larger. They are especially useful where large volumes of water are to be removed or when the groundwater surface is a large distance below ground surface. Commonly used pumps are the Grundfos® Redi-Flo2, the Geotech GeoSub, and the various ‘Monsoon’ style pumps. Other pumps are acceptable if constructed of suitable materials. When used with the Multiple-Volume Purge method, the pump is generally used only to purge, with sampling performed with a bailer. In this use, the pump can be used with polyethylene or other tubing or hose that will not contribute contaminants to the well. The pump and tubing is decontaminated between wells per the relevant provisions of SESD Operating Procedure for Field Equipment Cleaning and Decontamination (SESDPROC-205). When used in this application the pump should be equipped with a check valve to prevent water in the discharge tubing or hose from running back down into the well. When used for Low-Flow purging and sampling the pump must be constructed of stainless steel and Teflon®. Pump cleaning at each well follows the more stringent procedures described in SESD Operating Procedure for Field Equipment Cleaning and Decontamination SESDPROC-205) for this application. The sample tubing should be either new Teflon® tubing, or tubing dedicated to each well. Dedicated tubing would ideally be cleaned between uses, but tubing stored in the well casing between uses is acceptable, although caution should be exercised where very high concentrations of contaminants have been sampled in a well. 3.7.3 Use of Bailers Bailers are a common means of sampling when the Multiple-Volume Purge method is used. They are occasionally used for purging when other equipment is not available or has failed. As bailers surge the well on each withdrawal, it is very difficult to lower turbidity adequately during a well purge, and when used for sampling they can elevate turbidity in a well before all sample volume is collected. If not lowered carefully into the top of the water column, the agitation may strip volatile compounds. Due to the difficulties and limitations inherent in their use, other sampling or purging means should generally be given preference. COPY SESD Operating Procedure Page 26 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 Bailers should be closed-top Teflon® bailers with Teflon® coated stainless steel leaders used with new nylon haul rope. They are lowered gently into the top of the water column, allowed to fill, and removed slowly. It is critical that bailers be slowly and gently immersed into the top of the water column, particularly during final stages of purging and during sampling, to minimize turbidity and loss of volatile organic constituents. If the well has previously been purged with a pump, there is likely stagnant water at the top of the well that was above the pump or tubing inlet. Several bailers of water should be retrieved and discarded to assure the upper stagnant water has been removed. When sampling, containers are filled directly by pouring from the outlet at the top of the bailer. Containers for metals analysis should be filled first in case the bailing process increases well turbidity. VOC vials should be filled carefully and slowly with a laminar flow to reduce agitation and the stripping of VOCs. 3.7.4 Use of Bladder Pumps Bladder pumps use a source of compressed gas to compress and release a bladder straddled by check valves within the pump body. As the bladder is compressed, water is expelled out the upper check valve to the surface. When gas pressure is released, the bladder refills as well water enters the lower pump inlet. A control unit is used to control the pressure and timing of the bladder inflation gas flow. Bladder pumps are capable of pumping from moderate depths to water, but are not capable of high flow rates. As they operate cyclically, the well is surged slightly on each cycle and it may be difficult to lower turbidity in sensitive or poorly developed wells. As the entire sample train is under positive pressure and the pumps develop little heat, they are ideal for sampling VOCs. Prior to sampling and between each well the pumps are cleaned internally and externally per the provisions of SESD Operating Procedure for Field Decontamination (SESDPROC-205) and a new Teflon® bladder installed. New (or dedicated) Teflon® sample tubing is used at each well, although polyethylene tubing can be used for the compressed gas drive line and cleaned between each well. 3.7.5 Use of Inertial Pumps Inertial pumps consist of a check valve which is affixed to the lower end of semi-rigid tubing. The tubing and valve are cycled up and down, allowing water to alternately be drawn into the check valve inlet and then pulled up towards the surface. Two commonly used inertial pumps are the Waterrra® pump for wells 1arger than 1” and the Geoprobe® Tubing Check Valve for small diameter wells. The primary use of these pumps is in well development where their near-immunity to silt is an advantage. Inertial pumps should not be used for the final well purge or for sampling as there is a low likelihood of COPY SESD Operating Procedure Page 27 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 reducing turbidity to appropriate levels and they have the potential to strip volatiles from the water column through agitation. To set up the pump, the check valve is screwed onto the discharge tubing where it will cut its own threads. In the case of the Waterra® pump, a surge block can also be pressed onto the check valve. The pump is lowered into the well to the screened interval and rapidly cycled up and down a distance of 3” -12”. The stroke length and speed are adjusted for pumping effect. Electric actuators can be used to reduce the effort involved. The pump should be moved to different levels in the screen to surge the entire screen. The pump can occasionally be lowered to the bottom of the well to vacuum out silt. Any silt that clogs the valve is usually quickly rinsed out by the pump cycling and if the clog remains the pump is easily retrieved and redeployed. The surging activity is usually continued until turbidity is lowered to a measurable range and cannot easily be lowered further. Further development or purging is then conducted with other pumps. 3.8 Wells With In-Place Plumbing Wells with in-place plumbing are commonly found at municipal water treatment plants, industrial water supplies, private residences, and in other applications. Many permanent monitoring wells at active facilities are also equipped with dedicated, in-place pumps. A permanent monitoring well with an in-place pump may be treated as other monitoring wells without pumps. Since the in-place pump is generally “hard” mounted at a pre- selected depth, it cannot be moved up or down during purging and sampling. If the pump inlet is above the screened interval, the well should be sampled using the Multiple- Volume Purge method. If the pump intake is located within the screened interval, the well can be sampled using Low-Flow procedures. Known details of pump type and construction, tubing types, pump setting depths, and any other available information about the system should be recorded in the field logbook. In the case of the other types of wells, e.g., municipal, industrial and residential supply wells, there is typically not enough known about the construction aspects of the wells to apply the same criteria as used for monitoring wells. The volume to be purged in these situations therefore depends on several factors: whether the pumps are running continuously or intermittently and whether or not any storage/pressure tanks are located between the sampling point and the pump. The following considerations and procedures should be followed when purging wells with in-place plumbing under the conditions described. 3.8.1 Continuously Running Pumps If the pump runs more or less continuously, no purge (other than opening a valve and allowing it to flush for a few minutes) is necessary. If a storage tank is present, a spigot, COPY SESD Operating Procedure Page 28 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 valve or other sampling point should be found located between the pump and the storage tank. If no valve is present, locate and use the valve closest to the tank. Measurements of field parameters are recorded immediately prior to the time of sampling. 3.8.2 Intermittently or Infrequently Running Pumps If the pump runs intermittently or infrequently, best judgment should be utilized to remove enough water from the plumbing to flush standing water from the piping and any storage tanks that might be present. Often under these conditions, 15 to 30 minutes of purging will be adequate. Measurements of pH, specific conductance, temperature and turbidity should be made and recorded at intervals during the purge and the final measurements made at the time of sampling should be considered the measurements of record for the event. 3.9 Temporary Monitoring Wells 3.9.1 General Considerations As temporary wells are installed for immediate sample acquisition, the procedures used to purge temporary ground water monitoring wells may differ from those for permanent wells. Temporary wells include standard well screen and riser placed in boreholes created by hand augering or drilling, or they may consist of a drive rod and screen such as a direct-push Geoprobe® Screen Point that is driven into place at the desired sampling interval. As aquifer water enters the sampler immediately upon deployment, the requirement to remove several volumes of water to replace stagnant water does not necessarily apply. In practice, developing and purging the well to usable turbidity levels will remove many times the water that would be removed in a Multiple-Volume Purge with calculated well volumes. It is important to note, however, that the longer a temporary well is in place and not sampled, the more stagnant the water column becomes and the more appropriate it becomes to apply standard permanent monitoring well purging criteria to achieve representative aquifer conditions in the sample. 3.9.2 Development of Temporary Wells In cases where the temporary well is to be sampled immediately after installation, purging is conducted primarily to mitigate the impacts of installation. In most cases, temporary well installation procedures disturb the existing aquifer conditions, causing extreme turbidity. The goal of purging is to reduce the turbidity and remove the volume of water in the area directly impacted by the installation procedure. The following procedure has been found to be effective in developing and sampling small diameter temporary wells where a peristaltic pump can be used. Turbidity can generally be lowered to 50 NTU at the time of sampling and turbidity less than 10 NTU is often achieved. COPY SESD Operating Procedure Page 29 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 1. Cut peristaltic tubing to reach to the bottom of the well. Connect to a peristaltic pump and begin pumping at a high rate. 2. Use the tubing to vacuum out sediment at the bottom of the well. 3. Aggressively surge the end of the tubing in the screened interval by cycling the tubing rapidly up and down. Periodically repeat vacuuming of the well bottom. 4. When a visible ‘break’ to a lower turbidity is observed, cease surging the well and begin lowering the pumping rate. 5. When the water clears (turbidity < 100-200 NTU) begin raising the end of the tubing to the top of the water column. 6. Continue purging from the top of the water column, lowering the pump speed as required to lower turbidity. When adequately low turbidity and stable water quality parameters have been achieved, sampling can proceed. Where the water level is below the limit of suction in a small diameter temporary well, a Geoprobe® mechanical bladder pump can be used for purging and sampling. The well should first be developed with an inertial pump to remove the bulk of silt and suspended particles that could clog the check valves of the bladder pump. The inertial pump is used to vacuum out the bottom of the well and surged in the screened interval until a ‘break’ to lower turbidity is observed prior to deployment of the bladder pump. Since the mechanical bladder pump requires cumbersome redeployment to change its pumping level, it should be deployed low enough in the water column that the water level will not be lowered below the pump during purging and sampling. The mechanical bladder pump is generally deployed above the screened interval to facilitate the settling of particles, but below the top of the water column to alleviate the need to reset the pump. Detailed instructions on the deployment of the pump can be found in SESDPROC203, Pump Operation. 3.9.3 Decommissioning of Temporary Wells After temporary wells have fulfilled their purpose, they should be properly decommissioned similar to permanent wells. In general, the casings and screens can be easily removed and the borehole should then be pressure grouted from the bottom of the original borehole to prevent surface contamination of the aquifer, cross-connection of aquifers, and to remove a potential vapor pathway. Direct-push screen-point wells may be decommissioned by one of two methods. 1. A disposable screen is used. The sampling sheath is pulled off of the screen and a 30% solids bentonite grout is pumped down the tool string as the rods are withdrawn. COPY SESD Operating Procedure Page 30 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 Grout volumes are measured during pumping to assure that the hole is completely filled. The disposable screen is left behind at the bottom of the borehole. 2. The screen is removed with the sampler sheath and tool string. The hole is immediately re-entered with an empty sample sheath with disposable point. Upon reaching the original total depth of the temporary well, 30% solids bentonite grout is pumped down the tool string with the pumped volume monitored during tool string withdrawal to assure that the hole is completely filled. A system is available to insert a small diameter grouting tube down through the screen-point screen. Grout is pumped through the grouting tube while the tools are withdrawn. SESD does not use this system as grout denser than 20% solids cannot reliably be installed with this system. Additional guidance on decommissioning may be found in SESDGUID-101, Design and Installation of Monitoring Wells. 3.9.4 Other Considerations for Direct-Push Groundwater Sampling With certain direct push sampling techniques, such as the Hydropunch™ and other discrete samplers used with cone-penetrometer rigs, purging is either not practical or not possible. The sampling device is simply pushed or driven to the desired depth and opened, whereupon the sample is collected and retrieved. As a result, some samples collected in this way may not be satisfactory or acceptable for certain analyses, i.e., the sampler may collect a turbid sample inappropriate for metals analyses or the sample may have inadequate volume to achieve desired reporting levels. 3.10 Wells Purged to Dryness In some situations, even with slow purge rates, a well may be purged dry in the Multiple-Volume Purge method or stable drawdown cannot be maintained in the Low-Flow method. In these cases, the well should be purged to dryness (evacuated) and sampled upon recovery of adequate volume for sampling. Sampling should occur as soon as adequate volume has recovered. The field parameters should be measured and recorded at the time of sample collection as the measurements of record for the sampling event. Sampling under these conditions is not ideal and suitable qualifications of the data should be included in the report. Water cascading down the screen into the well may strip volatile compounds and elevate turbidity. Although suffering from other limitations, No-Purge methods may prove useful for these wells. COPY SESD Operating Procedure Page 31 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 4 Additional Purging and Sampling Considerations 4.1 Field Care of Purging Equipment New plastic sheeting should be placed on the ground surface around the well casing to prevent contamination of the pumps, hoses, ropes, etc., in the event they accidentally come into contact with the ground surface or, for some reason, they need to be placed on the ground during the purging event. It is preferable that hoses used in purging that come into contact with the ground water be kept on a spool or contained in a large wash tub lined with plastic sheeting, both during transportation and during field use, to further minimize contamination by the transporting vehicle or the ground surface. Careful consideration shall be given to using submersible centrifugal or bladder pumps to purge wells which are excessively contaminated with oily compounds as it may be difficult to adequately decontaminate severely contaminated pumps under field conditions. When wells of this type are encountered, alternative equipment, such as bailers or peristaltic pumps, should be considered. 4.2 Investigation Derived Waste Purging and field cleaning of equipment generates liquid investigation derived waste (IDW), the disposition of which must be considered. See SESD Operating Procedure for Management of Investigation Derived Waste (SESDPROC-202) for guidance on management or disposal of this waste. 4.3 Sample Preservation After sample collection, all samples requiring preservation must be preserved as soon as practical. Consult the Analytical Services Branch Laboratory Operations and Quality Assurance Manual (ASBLOQAM) for the correct preservative for the particular analytes of interest. All samples preserved using a pH adjustment (except VOCs) must be checked, using pH strips, to ensure that they were adequately preserved. This is done by pouring a small volume of sample over the strip. Do not place the strip in the sample. Samples requiring reduced temperature storage should be placed on ice immediately. 4.4 Special Sample Collection Procedures 4.4.1 Trace Organic Compounds and Metals Special sample handling procedures should be instituted when trace contaminant samples are being collected. All sampling equipment, including pumps, bailers, water level measurement equipment, etc., which contacts the water in the well must be cleaned in accordance with the cleaning procedures described in the SESD Operating Procedure for Field Equipment Cleaning and Decontamination (SESDPROC-205) or SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC (SESDPROC- COPY SESD Operating Procedure Page 32 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 206). Pumps should not be used for sampling unless the interior and exterior portions of the pump and the discharge hoses are thoroughly cleaned. Rinse blank samples should be collected to verify the adequacy of cleaning when using a sampling pump other than a peristaltic pump. 4.4.2 Order of Sampling with Respect to Analytes In many situations when sampling permanent or temporary monitoring wells, sufficiently low turbidity is difficult to achieve and maintain. Removal and insertion of equipment after the purge or during sampling may negate the low turbidities achieved during purging and elevate turbidity back to unacceptable levels. For this reason, it is important that special efforts be used to minimize any disturbance of the water column after purging and to fill sample containers for metals analysis first. The preferred order of sampling is metals first, followed by other inorganic analytes, extractable organic compounds, and finally volatile organic compounds. 4.5 Filtering As many contaminants are known to sorb to soil particles, the normal goal of sampling is to reduce the presence of these particles (measured by turbidity) in order that the dissolved concentration of contaminants can be obtained. However, transport of sorbed contamination on colloidal particles can be a means of contaminant transport on some sites. For this reason, the SESD approach is to reduce turbidity through the careful purging of wells, rather than through filtering of samples, in order that the colloidal particles would be included in the sample. As a standard practice, ground water samples will not be filtered for routine analysis. Filtering will usually only be performed to determine the fraction of major ions and trace metals passing the filter and used for flow system analysis and for the purpose of geochemical speciation modeling. Filtration is not acceptable to correct for improperly designed or constructed monitoring wells, inadequate well development, inappropriate sampling methods, or poor sampling technique. When samples are collected for routine analyses and are filtered, both filtered and non-filtered samples will be submitted for analyses. Samples for organic compounds analysis should not be filtered. Prior to filtration of the ground water sample for any reason other than geochemical speciation modeling, the following criteria must be demonstrated to justify the use of filtered samples for inorganic analysis: 1. The monitoring wells, whether temporary or permanent, have been constructed and developed in accordance with the SESD Guidance Document, Design and Installation of Monitoring Wells (SESDGUID-001). 2. The ground water samples were collected using sampling techniques in accordance with this section, and the ground water samples were analyzed in accordance with USEPA approved methods. COPY SESD Operating Procedure Page 33 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 3. Efforts have been undertaken to minimize any persistent sample turbidity problems. These efforts may consist of the redevelopment or re-installation of permanent ground water monitoring wells or the implementation of carefully conducted low flow rate sampling techniques. If filtration is necessary for purposes of geochemical modeling or other pre-approved cases, the following procedures are suggested: 1. Accomplish in-line filtration through the use of disposable, high capacity filter cartridges (barrel-type) or membrane filters in an in-line filter apparatus. The high capacity, barrel-type filter is preferred due to the higher surface area associated with this configuration. If a membrane filter is utilized, a minimum diameter of 142 mm is suggested. 2. When using pumps for sampling, the filter can generally be attached directly to the pump outlet. When sampling with a bailer or when otherwise required, an initial unfiltered sample with extra volume will be collected, and a peristaltic pump with filter used to decant and filter the sample to the final sample container. 3. Use a 0.45 μm pore-size filter to remove most non-dissolved particles. A 5 µm or 10 µm pore-size filter should be used for the purpose of determining colloidal constituent concentrations. 4. Fill the filter and rinse with approximately one additional filter volume prior to filling sample bottles Potential differences can result from variations in filtration procedures used to process water samples for the determination of trace element concentrations. A number of factors associated with filtration can substantially alter "dissolved" trace element concentrations; these include filter pore size, filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally-associated trace elements, and concentration of organic matter. Therefore, consistency is critical in the comparison of short-term and long-term results. Further guidance on filtration may be obtained from the following: 1) Metals in Ground Water: Sampling Artifacts and Reproducibility; 2) Filtration of Ground Water Samples for Metals Analysis; and 3) Ground Water Sampling - A Workshop Summary. See Section 1.4, References, for complete citation for these documents. 4.6 Bacterial Sampling Whenever wells (normally potable wells) are sampled for bacteriological parameters, care must be taken to ensure the sterility of all sampling equipment and all other equipment entering the well. Further information regarding bacteriological sampling is available in the following: 1) Sampling for Organic Chemicals and Microorganisms in COPY SESD Operating Procedure Page 34 of 34 SESDPROC-301-R4 Groundwater Sampling Groundwater Sampling(301)_AF.R4 Effective Date: April 26, 2017 the Subsurface; 2) Handbook for Evaluating Water Bacteriological Laboratories; and 3) Microbiological Methods for Monitoring the Environment, Water and Wastes. See Section 1.4, References, for complete citation for these documents. 4.7 Specific Sampling Equipment Quality Assurance Techniques All equipment used to collect ground water samples shall be cleaned as outlined in the SESD Operating Procedure for Field Equipment Cleaning and Decontamination (SESDPROC-205) or SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC (SESDPROC-206). Malfunctioning equipment should be labeled in the field and repaired, before being stored at the conclusion of field studies. Cleaning procedures utilized in the field or field repairs shall be thoroughly documented in field records. 4.8 Auxiliary Data Collection During ground water sample collection, it is important to record a variety of ground water related data. Included in the category of auxiliary data are water levels measured according to the SESD Operating Procedure for Groundwater Level and Well Depth Measurement (SESDPROC-105), well volume determinations, pumping rates during purging, and, driller or boring logs. This information should be documented in the field records. 4.9 Well Development Wells may be encountered that are difficult to sample effectively due to inadequate initial development or the need for redevelopment due to scaling, sedimentation, corrosion, or biofouling. These wells may produce water only at low flow rates or water with chronically elevated turbidity. Redevelopment of these wells should be considered as the process can improve sample quality and speed field operations. Well development procedures are described in Design and Installation of Monitoring Wells (SESDGUID- 101). COPY APPENDIX C FIELD INSTRUMENT CALIBRATION, OPERATION, AND MAINTENANCE PROCEDURES Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: In Situ Water Quality Monitoring ID: LSASDPROC-111-R5 Issuing Authority: FSB Branch Chief Effective Date: April 22, 2022 Next Review Date: April 22, 2026 Method Reference: NA Author: Mel Parsons Purpose The purpose of this procedure is to document acceptable practices in the use of multiparameter data sondes in the monitoring of in situ water quality parameters and dye tracer. Scope/Application This procedure covers the use of multiparameter data sondes for monitoring of in situ water quality including real-time measurement, profiling, and unattended data logging. In situ water quality parameters may include dissolved oxygen (DO), temperature, pH, conductivity, turbidity and chlorophyll. This procedure also applies to use of data sondes for monitoring dye tracer. While this SOP may be informative, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Note: LSASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, signatures, SOPs, and forms as they are developed, which will also be housed on the Local Area Network (LAN) and traceable to each project. In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 2 of 8 LSASDPROC-111-R5 042222 TABLE OF CONTENTS 1. Precautions _______________________________________________________________________ 3 1.1 Safety _______________________________________________________________________ 3 1.2 Equipment Handling ____________________________________________________________ 3 1.3 Calibration____________________________________________________________________ 3 2. Methodology ______________________________________________________________________ 4 2.1 General ______________________________________________________________________ 4 2.2 Real-time Monitoring ___________________________________________________________ 5 2.3 Profiling _____________________________________________________________________ 5 2.4 Unattended Deployment _________________________________________________________ 6 3. Definitions________________________________________________________________________ 6 References ____________________________________________________________________________ 7 Revision History _______________________________________________________________________ 8 In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 3 of 8 LSASDPROC-111-R5 042222 1. Precautions 1.1 Safety Equipment must be handled in a safe manner. Safety issues related to calibration or measurement of a specific parameter are addressed in individual parameter procedures. In addition, safety precautions should be followed in the deployment of data sondes. For unattended deployment in wadeable systems, data sondes should only be deployed and retrieved under safe flow/stage conditions. When deploying from a bridge, an amber flashing light should be operated on the roof of the field vehicle. When deploying from a boat, standard boating safety procedures should be followed. The LSASD Safety, Health and Environmental Management Program Procedures and Policy Manual, provides more information regarding field safety. 1.2 Equipment Handling To ensure the safe and reliable operation of equipment, the manufacturers’ directions for transport, cleaning, decontamination, storage and operation shall be followed. In general, upon return from the field and applicable data downloading, the batteries should be removed from the data sonde and the sonde washed via light brushing in warm, soapy water. Each probe should be cleaned and stored as directed by the manufacturer. Prior to use, data sondes shall be signed out in the Field Equipment Tracking System (FETS) according to LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-1009). When unattended deployment is anticipated, pingers should be attached to the sonde, as feasible, to aid in recovery should the sonde be displaced during deployment. Upon return, equipment shall be signed in through FETS, noting any issues with equipment. 1.3 Calibration Prior to use, each sonde probe should be calibrated according to the specific parameter measurement procedure. However, because the sonde is a multi-probe unit, additional care must be taken to prevent cross-contamination of calibration standards. Similarly, calibration of multiple sonde units requires cross-contamination prevention procedures. Specifically, following immersion of the sonde probes into each calibration standard, all probes should be thoroughly rinsed in distilled or de-ionized water and the excess water shaken off or blotted dry with a lint-free wipe. Conductivity standards are much more sensitive to cross contamination/dilution than other standards; therefore, prior to immersion in a conductivity standard, all probes should be thoroughly rinsed and completely dried with lint-free wipes or compressed air. The conductivity probe on the sondes provides a linear reading of conductivity across the scale, so it is no longer necessary, as in some older technology meters, to calibrate with a standard close to what one may expect in the field. Therefore, due to the propensity of the standard to be easily diluted, one should use a relatively high concentration standard (typically in the 10,000 umho range) for conductivity calibrations. In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 4 of 8 LSASDPROC-111-R5 042222 Besides being easily diluted, conductivity also affects other parameters (specifically DO), therefore conductivity should always be the first parameter calibrated. The recommended order for calibration of the individual probes on a multiparameter sonde is as follows: 1. Conductivity 2. pH 3. DO 4. Turbidity/Chlorophyll/Rhodamine in any order Rhodamine and Chlorophyll probes are calibrated in a similar fashion to turbidity. Specifically, the zero level is set using DI or distilled water followed by calibration to a known standard (typically 100 ppb for Rhodamine). 2. Methodology 2.1 General With multiple probe options and customizable configuration, data sondes are extremely versatile tools for the measurement of in situ water quality. Effective use of multi-parameter sondes takes additional planning and procedures beyond those described in the individual operating procedures for each parameter (i.e., DO measurement, pH measurement, etc.). Data sondes may be operated and/or programmed via the manufacturer’s display unit generic tablets, smart phones, or a laptop computer. In either case, it is recommended that the user take the manufacturer’s applicable User Manual in the field should difficulties be encountered. If the display unit does not have a power indicator, the batteries should be checked or the unit charged, as applicable, prior to use. Power to the sonde may be supplied by the display unit or by the internal batteries installed in the sonde (a setting on the display unit menu). If the sonde is being powered by the display unit, it is possible to calibrate and set up the sonde for unattended deployment, when in fact there are no batteries in the sonde (the battery voltage being read is for the display unit and not for the sonde). Therefore, it is very important to ensure that there are actually batteries in the sonde. Calibration and programming for unattended deployment uses very little battery power, therefore, it is recommended that sondes be powered from their own internal batteries and not from the display unit. New alkaline or freshly charged nickel metal hydride (NMiH) batteries should be installed in each sonde prior to each field study. Generally, if the sondes will be deployed on multiple occasions during a field study, new alkaline batteries should be installed when the sonde voltage falls below 11.5 volts at end check. Nickel metal hydride (NMiH) batteries operate at a lower voltage than alkaline (1.2 volts vs. 1.5 volts); therefore, if using rechargeable batteries, they should be recharged or replaced if voltage falls below 10.5 volts. Specific units require that, for the parameters of interest, the appropriate sensor be enabled via the display or laptop prior to use. The field investigator should follow manufacturer’s procedures to ensure all required probes are functioning. If a particular parameter is not needed, the sensor should be turned off, via the menu, in order to conserve battery power. It should be noted that turning the reporting of the parameter off does not turn off the probe, it simply turns off the display of the parameter (the parameter is still being logged). One must go into the “Sensor” menu to actually turn off the sensor. In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 5 of 8 LSASDPROC-111-R5 042222 2.2 Real-time Monitoring Real-time monitoring entails observing monitoring data via display unit or laptop computer as data is collected by the sonde. This data may be recorded in a field logbook or logged to the internal memory of the sonde if so equipped. Logged data should be downloaded to a laptop or desktop computer as soon as possible. It is also recommended that download files be backed up in a separate location. In addition, even when logging data at regular intervals, it is recommended for real-time monitoring that data also be recorded in a field logbook at some reasonable interval to ensure that some data is captured should the instrument logger fail. Real-time monitoring generally involves hand-held deployment or attachment to a stationary object at the monitoring location. Hand-held deployments are useful for short-term monitoring in small, wadeable streams. For longer monitoring periods or to hold the sonde at a specific depth, attachment to a fixed object may be more effective. Fixed objects may include rocks or embedded logs already in place at the site or may include fence posts or rods placed by the field investigator prior to monitoring. Sondes may also be hung at desired depths from a boat on larger water bodies. 2.3 Profiling Profiling involves real-time monitoring or individual measurements at several depths through a water column. Profiling is especially useful for documenting water column gradients or stratification of in situ parameters or for evaluating complete mix conditions in dye tracer studies. Profiling deployments are generally conducted by hand to provide the movement of the sonde through the water column; however, profiling can also be conducted using mechanical/ electrical winch or reel type devices. In profiling applications, the profiling cable should be labeled in some manner to indicate depth or the sonde calibrated to accurately read depth on the display unit. In general, profiling data is recorded in a field logbook along with the location and depth information for each measurement. In fast moving waters it may be necessary to attach weight to the sonde to ensure the sonde is hanging as vertically as possible in the water column. Weights should always be attached to the probe guard or sonde body, not the individual probes. If attached to the probe guard, weights should be secured in such a way that the weights and attachments do not interfere with probe operation. In all real-time and profiling applications, especially when the sonde is weighted, it is important to ensure that the profiling cable is securely attached to the baling harness of the sonde to prevent a disconnection of the sonde and potential loss or damage to the sonde. It is important to note that LSASD has two general types of sondes, vented and non-vented. Each type of sonde has its own profiling cable. The difference is how the depth sensor works. Non-vented sondes have a standard pressure or depth sensor that can be zeroed out at the site and will then accurately measure depth, typically to within a half a foot or less. Vented sondes have a small hole in the center of the connector pins where the cable attaches and are typically used to accurately measure, (+/- 0.01 feet), changes in water stage level in unattended deployments, but may also be used for profiling applications. In order for a vented sonde to accurately measure depth or stage, the sonde MUST be used with a vented cable which vents to the atmosphere. If a vented sonde is used with a non-vented cable it will NOT give accurate depth readings. When a vented sonde is used with a vented cable, just In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 6 of 8 LSASDPROC-111-R5 042222 zero the depth at the site and measure depth as with a non-vented sonde. In addition, since vented sondes are typically used for stage measurements, the depth sensor is only rated to a maximum depth of 30 feet, whereas non-vented sondes are typically rated to 200 feet. 2.4 Unattended Deployment Unattended deployment entails pre-programming and deployment of a sonde at a specific location to log monitoring data in the absence of observation by a field investigator. Unattended deployments are useful for collecting data at regular intervals over extended monitoring periods, frequently up to 3 – 4 days. However, since all data is recorded internally for the duration of the deployment, it is critical that all programming parameters are verified to be correct prior to deployment. Programming of the sonde should follow the manufacturer’s procedures for unattended deployment. The sonde may be programmed in the lab prior to a field study or programmed in the field. Programming of the sonde is typically accomplished either by the sonde’s display unit or by laptop computer. Programming requires input of a start data/time, deployment duration, data log file name, and monitoring interval. The sonde clock and programming times should always be input in local time for the study area, unless otherwise noted in the field log. The field logbook should also include the sonde identifier, the local date/time of initial deployment, local date/time of retrieval, deployment location, and sonde depth. In addition to enabling the required probes as described in Section 2.1, some units require further identification of the parameters to be included in the logged data file. The field investigator should follow manufacturer’s procedures to ensure all necessary data will be successfully logged. 3. Definitions None In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 7 of 8 LSASDPROC-111-R5 042222 References LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-1009, Most Recent Version LSASD Operating Procedure for Field Measurement of Dissolved Oxygen, LSASDPROC-106, Most Recent Version LSASD Operating Procedure for Field pH Measurement, LSASDPROC-100, Most Recent Version LSASD Operating Procedure for Field Specific Conductance Measurement, LSASDPROC-101, Most Recent Version LSASD Operating Procedure for Field Turbidity Measurement, LSASDPROC-103, Most Recent Version US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version In Situ Water Quality Monitoring Effective Date: April 22, 2022 Approved by FSB Chief Page 8 of 8 LSASDPROC-111-R5 042222 Revision History History Effective Date LSASDPROC-111-R5, In Situ Water Quality Monitoring, replaces SESDPROC-111-R4 General: Corrected any typographical, grammatical, and/or editorial errors. Additionally, the document was edited to reflect the new Division name and standardized SOP format. April 22, 2022 SESDPROC-111-R4, In Situ Water Quality Monitoring, replaces SESDPROC-111-R3 General: Corrected any typographical, grammatical, and/or editorial errors. Additionally, the document was edited to reflect new Document Control Processes. March 14, 2018 SESDPROC-111-R3, In Situ Water Quality Monitoring, replaces SESDPROC-111-R2 July 19, 2013 SESDPROC-111-R2, In Situ Water Quality Monitoring, replaces SESDPROC-111-R1 December 7, 2009 SESDPROC-111-R1, In Situ Water Quality Monitoring, replaces SESDPROC-111-R0 November 1, 2007 SESDPROC-111-R0, In Situ Water Quality Monitoring, Original Issue April 1, 2007 Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field Measurement of Dissolved Oxygen ID: LSASDPROC-106-R4 Issuing Authority: LSASD Field Branch Chief Effective Date: April 9, 2021 Next Review Date: April 9, 2025 Purpose This document describes methods and considerations to be used and observed when conducting field measurements of dissolved oxygen in surface water, treated wastewater and in gas media for specific applications (e.g., reaeration measurement). Scope/Application On the occasion that LSASD field investigators determine that any of the procedures described in this procedure are inappropriate, inadequate or impractical and that another method must be used to obtain a measurement of dissolved oxygen, the alternate procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Note: LSASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, and report forms as they are developed, which will also be housed in the LIMS and traceable to each project. LSASD is committed to maintaining its quality system by continued traceability of original observations in the final report as migration to an electronic system occurs. Next Review Date: Next Review Date: April 9, 2025 his document describes methods and considerations to be used and observed when conducting his document describes methods and considerations to be used and observed when conducting field measurements of dissolved oxygen in surface water, treated field measurements of dissolved oxygen in surface water, treated for specific applications (e.g., reaeration measurement). for specific applications (e.g., reaeration measurement). n the occasion that LSASD field investigators determine that any of the procedures described n the occasion that LSASD field investigators determine that any of the procedures described procedure are inappropriate, inadequate or impractical and that another method must be procedure are inappropriate, inadequate or impractical and that another method must be used to obtain a measurement of dissolved oxygen, the alternate procedure will be documented used to obtain a measurement of dissolved oxygen, the alternate procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Mention of in the field logbook, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. or recommendation for use. ASD is currently migrating to a paperless organization. As a result, this SOP will allow ASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, and report forms as they are developed, which will Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 2 of 12 LSASDPROC-106-R4 040921 TABLE OF CONTENTS 1. Documentation/Verification _________________________________________________ 3 2. Safety __________________________________________________________________ 3 3. Quality Control ___________________________________________________________ 3 4. Field Measurement of Dissolved Oxygen_______________________________________ 4 6. References_______________________________________________________________ 9 Revision History _____________________________________________________________ 10 ________________________________________________________________ _______________________________ 9_______________________________ 9 Revision History _____________________________________________________________ 10Revision History _____________________________________________________________ 10 Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 3 of 12 LSASDPROC-106-R4 040921 General Information 1. Documentation/Verification 1.1. This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD Local Area Network (LAN). The Quality Assurance Coordinator (QAC) is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance (LSASDPLAN-1000). 2. Safety 2.1. Refer to the Region 4 Safety & Occupational Health website for the Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. When using this procedure, minimize exposure to potential health hazards through the use of protective clothing, eye wear and gloves. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 2.2. Appropriate precautions should be observed when working in and around bodies of water and on boats. Be aware of fast flowing waters, waterway obstructions such as dams, and other vessels on the water. 3. Quality Control 3.1. All dissolved oxygen meters will be maintained and operated in accordance with the manufacturer's instructions and the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-1009). Before a meter is utilized in the field, it will be calibrated and verified, according to Section 4.4 of this procedure, to ensure it is operating properly. These calibration and verification checks will be documented and maintained in a logbook (SESDPROC-1002). 3.2. For in-situ measurements, an instrument warm-up period appropriate for that instrument should be provided. Consult manufacturer’s documentation for appropriate warm-up time. 3.3. The ambient temperature in the immediate vicinity of the meter should be measured and recorded in the field logbook to ensure the instrument is operated within the manufacturer’s specified range of operating temperatures. For instruments that are deployed for in-situ measurements, the temperature of the medium being monitored Region 4 Safety & Occupational Health website for the Procedures and Region 4 Safety & Occupational Health website for the Procedures and specific Health and Safety Plans (HASPs) for specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to guidelines on safety precautions. These guidelines, however, should only be used to judgment of an experienced professional. When using this procedure, judgment of an experienced professional. When using this procedure, minimize exposure to potential health hazards through the use of protective clothing, eye minimize exposure to potential health hazards through the use of protective clothing, eye wear and gloves. Address chemicals that pose specific toxicity or safety concerns and wear and gloves. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. follow any other relevant requirements, as appropriate. Appropriate precautions should be observed when working in and around bodies of Appropriate precautions should be observed when working in and around bodies of and on boats. Be aware of fast flowing waters, waterway obstructions such as and on boats. Be aware of fast flowing waters, waterway obstructions such as dams, and other vessels on the water. dams, and other vessels on the water. All dissolved oxygen metersmeters will will manufacturer's instructions and the manufacturer's instructions and the and Management and Management be calibrated and verified, according to Section 4.4 of this procedure, to be calibrated and verified, according to Section 4.4 of this procedure, to ensure it is operating properly. These calibration ensure it is operating properly. These calibration documented and maintained in a logbook documented and maintained in a logbook Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 4 of 12 LSASDPROC-106-R4 040921 3.4. should be measured and recorded in the logbook prior to deployment. In-situ monitoring equipment may be utilized in unattended deployments where autonomous logging may preclude temperature measurement prior to deployment. Because in-situ instrumentation generally has a wide range of operating temperature, the field investigator may utilize professional judgment in determining if the operating environment is suitable for unattended deployment. 3.5. Following instrument use, an end check should be performed using one of the techniques described in Section 4.4 to quantify potential instrument drift during use. 3.6. If at any time during a field investigation, it appears that the environmental conditions could jeopardize the quality of the measurement results, the measurements will be stopped. This will be documented in the field logbook. 4. Field Measurement of Dissolved Oxygen 4.1. General 4.1.1. Dissolved oxygen can be defined as the mass of molecular oxygen contained in a volume of water. The solubility of oxygen in water is dependent on the water temperature, salinity and atmospheric pressure. As the temperature of the water decreases, the solubility of oxygen increases. As salinity increases, the solubility of oxygen decreases. As atmospheric pressure decreases (altitude increases), the solubility of oxygen decreases. 4.1.2. Several methods for measurement of dissolved oxygen in water are available utilizing a variety of technologies. When measuring dissolved oxygen for compliance with the National Pollutant Discharge Elimination System (NPDES) Program, only approved methods will be used. Approved methods can be found in the Code of Federal Regulations (CFR) 40 CFR Part 136. 4.2. Clark Cell Probes 4.2.1. Clark cell probes utilize an oxygen permeable membrane that covers an electrolytic cell which consists of a cathode and an anode. The anode acts as a reference electrode. After passing through the permeable membrane, the oxygen is reduced by an applied potential voltage that is referenced to the anode. The reduction current at the cathode is directly proportional to the partial pressure of oxygen in liquid, expressed as %-air saturation. The concentration of oxygen, in mg/l, is calculated based on the %-air saturation reading and the solubility of oxygen in water at the sample temperature. As the temperature of the water decreases, the As the temperature of the water decreases, the As salinity increases, the As salinity increases, the solubility atmospheric pressure decreases (altitude increases), the atmospheric pressure decreases (altitude increases), the oxygen decreases. oxygen decreases. Several methods for measurement of dissolved oxygen in water are avSeveral methods for measurement of dissolved oxygen in water are av utilizing a variety of technologies. When measuring dissolved oxygen for utilizing a variety of technologies. When measuring dissolved oxygen for compliance with the National Pollutant Discharge Elimination System (NPDES) compliance with the National Pollutant Discharge Elimination System (NPDES) Program, only approved methods will be used. Approved methods Program, only approved methods will be used. Approved methods Code of Code of mass mass of of of oxygen in water is dependent on the water of oxygen in water is dependent on the water atmospheric pressure. atmospheric pressure. As the temperature of the water decreases, the As the temperature of the water decreases, the could jeopardize the quality of the measurement results, the measurements will be could jeopardize the quality of the measurement results, the measurements will be molecular Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 5 of 12 LSASDPROC-106-R4 040921 4.2.2. In general, sample collection using a DO probe requires only lowering the probe into the sample media and recording or logging the results. The probe should be lowered gently to prevent damage to the membrane and gently turned when initially lowered to remove any attached air bubbles. If the instrument requires the use of a stirrer, the stirrer should be turned on before recording any readings. Prior to use, the instrument should be calibrated, and any manufacturer specified warm-up period should be observed. 4.3. Luminescent Probes 4.3.1. Luminescent dissolved oxygen probes employ a light emitting diode (LED) to provide incident light, which excites the oxygen-sensitive luminescent-dye molecule substrate of the sensor. After dissipation of the excitation energy, longer- wavelength light is emitted (luminescence). The magnitude of steady-state luminescence (intensity) is measured by the sensor and is inversely proportional to the dissolved oxygen concentration. 4.3.2. Sample collection with this type of probe should follow the sample procedures described in of Section 4.2.2 for Clark Cell probes. 4.4. Calibration 4.4.1. Many brands of instruments are commercially available for in-situ measurement of dissolved oxygen using Clark cell probes and luminescent probes. The manufacturer’s instruction manual should be consulted for specific procedures regarding their calibration, maintenance and use. Calibration of any measurement instrument must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate or dictated by Data Quality Objectives (DQOs). 4.4.2. In general, calibrations should be conducted at temperatures and pressures as close as possible to those of the sample media for the most accurate measurements. Due to the sensitivity of dissolved oxygen measurements to changes in temperature, the temperature probe or thermistor should be verified using a NIST traceable thermometer prior to each calibration. Most dissolved oxygen meters utilize a one- point calibration which is generally performed using either water-saturated air or air-saturated water. However, some optical DO meters are capable of a two-point calibration at 0% and 100% saturation, refer to Section 4.4.2.3 for applicability. of dissolved oxygen using Clark cell probes and luminescent probes. The of dissolved oxygen using Clark cell probes and luminescent probes. The manufacturer’s instruction manual should be consulted for specific procedures manufacturer’s instruction manual should be consulted for specific procedures regarding their calibrationregarding their calibration, maintenance and use., maintenance and use. must be conducted and/or verified prior to each use or on a daily basis, must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate whichever is most appropriate In general, calibrations should be conIn general, calibrations should be con close as possible to those of the sample media for the most accurate measurements. close as possible to those of the sample media for the most accurate measurements. Due to the sensitivity of dissolved oxygen measurements to changes in temperature, Due to the sensitivity of dissolved oxygen measurements to changes in temperature, the temperature probe or thermistor should be verthe temperature probe or thermistor should be ver thermometer prior to each calibration. Most dissolved oxygen meters utilize a one-thermometer prior to each calibration. Most dissolved oxygen meters utilize a one- point calibration which is generally performed using either water- described in of Section 4.2.2 for Clark Cell probes. Many brands of instruments are commercially available for in-Many brands of instruments are commercially available for in- of dissolved oxygen using Clark cell probes and luminescent probes. The of dissolved oxygen using Clark cell probes and luminescent probes. The substrate of the sensor. After dissipation of the excitation energy, longer-substrate of the sensor. After dissipation of the excitation energy, longer- wavelength light is emitted (luminescence). The magnitude of steadywavelength light is emitted (luminescence). The magnitude of steady ty) is measured by the sensor and is inversely proportional to ty) is measured by the sensor and is inversely proportional to Sample collection with this type of probe should follow the sample procedures Sample collection with this type of probe should follow the sample procedures described in of Section 4.2.2 for Clark Cell probes. described in of Section 4.2.2 for Clark Cell probes. Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 6 of 12 LSASDPROC-106-R4 040921 4.4.2.1. Water-Saturated Air Method 4.4.2.1.1. When using the water-saturated air method, the probes should be placed in a 100% relative humidity environment open to ambient air temperature and barometric pressure. Allow at least 10-15 minutes for the temperature and dissolved oxygen readings to equilibrate. Ensure that water droplets are removed from the luminescence cap or Clark cell membrane and thermistor before calibration. Refer to Section 4.7 for calibration verification procedure. 4.4.2.2. Air-Saturated Water Method 4.4.2.2.1. When using air-saturated water for calibration, an aeration device such as an aquarium pump with a diffusion stone should be placed in a vessel containing tap water. The water in the vessel should be aerated for a minimum of one hour at a constant temperature. Saturation should be verified by placing the dissolved oxygen probe in the vessel and monitoring the temperature and dissolved oxygen readings for stabilization. Avoid placing the probe in the direct stream of air bubbles. Bubbles can accumulate on the probe surface and cause erroneous readings. Refer to Section 4.7 for calibration verification procedure. 4.4.2.3. Zero-DO Verification and 2-Point Calibration 4.4.2.3.1. It is recommended that a zero-DO verification is conducted periodically or when concentrations are expected to be below 1 mg/l (USGS, 2013a). A zero-DO solution can be prepared by dissolving 1 gram of sodium sulfite in 1 liter of deionized water. This should be made fresh weekly or as needed. If the unit is equipped with a wiper, it should be removed before immersing in zero-DO solution. The reading should not exceed a concentration of 0.2 mg/l dissolved oxygen in the zero-DO solution. For Clark cells that exceed this concentration, replace the electrolyte and membrane before repeating the zero-DO verification process. For optical probes that read above 0.2 mg/l in zero-DO solution, replace the sensor cap if it is expired or perform a 2-point calibration if applicable. Some optical DO probes are capable of 2-point calibrations using a zero-DO solution and the air-saturated water method discussed in Section 4.4.2.2. Refer to the manufacturer’s instruction manual for the appropriate 2-point calibration procedure. Ensure that the probe is thoroughly rinsed of zero-DO solution after verification or calibration to avoid measurement interferences caused by residual sodium sulfite. Verification and 2and 2 It is recommended that a zeroIt is recommended that a zero periodically or when concentraperiodically or when concentra , 2013a, 2013a). A zero). A zero gram of sodium sulfite in 1 liter of deionized water. This should be made gram of sodium sulfite in 1 liter of deionized water. This should be made fresh weekly or as needed. fresh weekly or as needed. be removed before immersing in zerobe removed before immersing in zero not exceed a concentration of 0.2 mg/l dissolved oxygen in the zero-not exceed a concentration of 0.2 mg/l dissolved oxygen in the zero- solution. solution. electrolyte and membrane before repeating the zeroelectrolyte and membrane before repeating the zero monitoring the temperature and dissolved oxygen readings for stabilization. Avoid placing the probe in the direct stream of air bubbles. stabilization. Avoid placing the probe in the direct stream of air bubbles. Bubbles can accumulate on the probe surface and cause erroneous Bubbles can accumulate on the probe surface and cause erroneous 4.7 for calibration verification procedure. 4.7 for calibration verification procedure. and 2and 2-Point CalibrationPoint Calibration saturated water for calibration, an aeratisaturated water for calibration, an aerati such as an aquarium pump with a diffusion stone should be placed in a such as an aquarium pump with a diffusion stone should be placed in a The water in the vessel should be aerated for The water in the vessel should be aerated for a minimum of one hour at a constant temperature. Saturation should be a minimum of one hour at a constant temperature. Saturation should be verified by placing the dissolved oxygen probe in the vessel and verified by placing the dissolved oxygen probe in the vessel and monitoring the temperature and dissolved oxygen readings for monitoring the temperature and dissolved oxygen readings for stabilization. Avoid placing the probe in the direct stream of air bubbles. Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 7 of 12 LSASDPROC-106-R4 040921 4.5. Maintenance 4.5.1. Maintenance procedures vary depending on the technology utilized by each instrument and the manufacturer. The manufacturer’s instruction manual should be consulted for instrument specific procedures. Following are some general guidelines for maintaining dissolved oxygen meters: Inspect probes for damage prior to use. For Clark cell probes, membranes and electrolyte solution should be changed prior to each study, when feasible. Battery voltages should be checked. For meters that will be deployed unattended, new or fully charged batteries should be used for each study. All calibration and maintenance procedures performed should be thoroughly documented. 4.6. Conducting Field Measurement of Dissolved Oxygen 4.6.1. Following are guidelines for conducting field measurements of dissolved oxygen: Except as described in specific operating procedures, dissolved oxygen measurements should if possible be conducted in-situ. When measuring DO at distinct points in the water column, the probe should be allowed to equilibrate at each location prior to recording the measurement. In water bodies with a great deal of flow, a weight may be attached to the probe guard or support cable to ensure the probe is maintained at the proper depth. Ensure that the measurement location is representative of conditions within the water body or reach. Avoid measurements directly below turbulent sections or still water unless these conditions represent most of the water body or reach. The DO meter should be capable of autocorrecting for specific conductivity/salinity or a separate instrument should be used to measure specific conductivity/salinity so that the final DO measurement(s) can be corrected. 4.7. Operational Verification 4.7.1. A post-calibration and post-operation instrument verification check should be performed using one of the techniques described in Sections 4.4.2.1 and 4.4.2.2 or 4.4.2.3 (for 2-point calibrations) to quantify potential instrument drift during use. A verification check will be performed after a calibration and at the end of all measurements. When measuring DO at distinct points in the water column, the probe should be allowed to equilibrate at each location prior to recording the be allowed to equilibrate at each location prior to recording the In water bodies with a great deal of flow, a weight may be attached to the In water bodies with a great deal of flow, a weight may be attached to the probe guard or support cable to ensure the probe is maintained at the proper probe guard or support cable to ensure the probe is maintained at the proper that the measurement location is representative of conditions within that the measurement location is representative of conditions within the water body or reach. Avoid measurements directly below turbulent the water body or reach. Avoid measurements directly below turbulent sections or still water unless these conditions represent most of the water sections or still water unless these conditions represent most of the water body or reach. body or reach. TheThe DO DO conductivity/salinity or a separate instrument should be used to measure conductivity/salinity or a separate instrument should be used to measure Following are guidelines for conducting field measurements of dissolved oxygen: Following are guidelines for conducting field measurements of dissolved oxygen: Except as described in specific operating procedures, dissolved oxygen Except as described in specific operating procedures, dissolved oxygen measurements should if possible be conducted in-measurements should if possible be conducted in- When measuring DO at distinct points in the water column, the probe should When measuring DO at distinct points in the water column, the probe should be allowed to equilibrate at each location prior to recording the unattended, new or fully charged batteries should be used for each study. unattended, new or fully charged batteries should be used for each study. All calibration and maintenance procedures performed should be thoroughly All calibration and maintenance procedures performed should be thoroughly Following are guidelines for conducting field measurements of dissolved oxygen: Following are guidelines for conducting field measurements of dissolved oxygen: Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 8 of 12 LSASDPROC-106-R4 040921 4.7.2. It may be appropriate to verify the calibration of a DO meter periodically during the course of a day’s measurements when conducting individual measurements. A DO probe may be re-calibrated throughout the day if drift is occurring. The verification DO concentration should be measured and recorded in the field logbook prior to any instrument adjustment. For long-term deployments a post-operation verification should be performed at the end of the deployment. 4.7.3. Verification is done by comparing a post-calibration or post-operation reading at 100% saturation conditions to a DO solubility table value at the ambient air/water temperature and barometric pressure. Post-calibration and post-operation readings should not exceed a maximum of ± 0.2 mg/l from the DO solubility table value. DO solubility tables can be accessed via the U.S. Geological Survey’s DOTABLES software (USGS, 2013b) which are based on equations from Benson and Krause (1980; 1984). USGS, 2013b) which are based on equations from Benson and Krause USGS, 2013b) which are based on equations from Benson and Krause Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 9 of 12 LSASDPROC-106-R4 040921 6. References Benson, B.B., and Krause, D., Jr, 1980. The concentration and isotopic fractionation of gases dissolved in freshwater in equilibrium with the atmosphere—1. Oxygen: Limnology and Oceanography, v. 25, no. 4, p. 662–671. Benson, B.B., and Krause, D., Jr, 1984. The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere: Limnology and Oceanography, v. 29, no. 3, p. 620–632. LSASDPLAN-1000, LSASD Quality Management Plan, Most Recent Version. LSASDPROC-1009, LSASD Operating Procedure for Equipment Inventory and Management, Most Recent Version. SESDPROC-1002, SESD Operating Procedure for Logbooks, Most Recent Version. Region 4 Safety & Occupational Health at: https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource s.aspx USGS, 2013a. Dissolved Oxygen (ver. 3.0): U.S. Geological Survey Techniques of Water- Resources Investigations, book 9, chap. A6, sec. 6.2, http://water.usgs.gov/owq/FieldManual/Chapter6/6.2_v3.0.pdf. USGS, 2013b. DOTABLES (ver. 3.5): Dissolved Oxygen Solubility Tables, https://water.usgs.gov/software/DOTABLES/. Resources Investigations, book 9, chap. A6, sec. 6.2, Resources Investigations, book 9, chap. A6, sec. 6.2, http://water.usgs.gov/owq/FieldManual/Chapter6/6.2_v3.0.pdf. http://water.usgs.gov/owq/FieldManual/Chapter6/6.2_v3.0.pdf. USGS, 2013b. DOTABLES (ver. 3.5): Dissolved Oxygen Solubility Tables, USGS, 2013b. DOTABLES (ver. 3.5): Dissolved Oxygen Solubility Tables, https://water.usgs.gov/software/DOTABLES/. https://water.usgs.gov/software/DOTABLES/. https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resourcehttps://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource USGS, 2013a. Dissolved Oxygen (ver. 3.0): U.S. Geological Survey Techniques of Water-USGS, 2013a. Dissolved Oxygen (ver. 3.0): U.S. Geological Survey Techniques of Water- Resources Investigations, book 9, chap. A6, sec. 6.2, Resources Investigations, book 9, chap. A6, sec. 6.2, -1009, LSASD Operating Procedure for Equipment Inventory and Management, -1009, LSASD Operating Procedure for Equipment Inventory and Management, -1002, SESD Operating Procedure for Logbooks, Most Recent Version. -1002, SESD Operating Procedure for Logbooks, Most Recent Version. https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 10 of 12 LSASDPROC-106-R4 040921 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Document Control Coordinator on the SESD local area network (LAN). History Date Minor edits. Changes to the health and safety references. Formatted the SOP to the new approved format. April 9, 2021 SESDPROC-106-R4, Field Measurement of Dissolved Oxygen, replaces SESDPROC-106-R3 General: Corrected any typographical, grammatical, and/or editorial errors. In addition, any references to former Division organizational structure was updated to reflect current structure. Title Page: Changed the Author from Hunter Johnson to Nathan Barlet. Changed the Field Quality Manager from Bobby Lewis to Hunter Johnson. Updated cover page to represent SESD reorganization. Table of Contents: Added Sections 3.2.1 Water-Saturated Air Method, 3.2.2 Air-Saturated Water Method, and 3.2.3 Zero-DO Verification & 2- Point Calibration. Changed Section 3.5 from “Operational Check” to “Operational Verification.” Updated page numbers. Section 1.4: Added the citations for Benson and Krause (1980), Benson and Krause (1984), USGS (2013a), and USGS (2013b) as references, Section 3.1: Changed “volume of oxygen contained in a volume of water” to “mass of molecular oxygen contained in a volume of water.” Changed “pressure” in first paragraph and third bullet point to “atmospheric pressure.” Section 3.2: Added “However, some optical DO meters are capable of a two-point calibration at 0% and 100% saturation, refer to Section 3.2.3 for applicability.” Added Section 3.2.1 Water-Saturated Air Method, which includes information on the calibration procedure for the water-saturated air method. Added “Allow at least 10-15 minutes for the temperature and dissolved oxygen readings to equilibrate. Ensure that water droplets are removed from the luminescence cap or Clark cell membrane and thermistor before calibration. Refer to Section 3.5 for calibration verification procedure.” Added Section 3.2.2 Air-Saturated Water Method, which includes information on the calibration procedure for the air-saturated water method. Added “Refer to Section 3.5 for calibration verification procedure.” April 12, 2017 Added the citations for Benson and Krause (1980), Benson Added the citations for Benson and Krause (1980), Benson ), and USGS (2013), and USGS (2013bb) as references,) as references, Changed “volume of oxygen contained in a volume of Changed “volume of oxygen contained in a volume of water” to “mass of molecular oxygen contained in a volume of water.” water” to “mass of molecular oxygen contained in a volume of water.” Changed “pressure” in first paragraph and third bullet point to Changed “pressure” in first paragraph and third bullet point to Added “However, somAdded “However, som point calibration at 0% and 100% saturation, refer to Section 3.2.3 point calibration at 0% and 100% saturation, refer to Section 3.2.3 Saturated Air Method, Saturated Air Method, DO Verification DO Verification & 2& 2 Point Calibration. Changed Section 3.5 from “Operational Check” to Point Calibration. Changed Section 3.5 from “Operational Check” to anged the Field Quality Manager from Bobby Lewis to Hunter anged the Field Quality Manager from Bobby Lewis to Hunter Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 11 of 12 LSASDPROC-106-R4 040921 Added Section 3.2.3 Zero-DO Verification & 2-Point Calibration. Added “It is recommended that a zero-DO verification is conducted periodically or when concentrations are expected to be below 1 mg/l (USGS, 2013a). A zero-DO solution can be prepared by dissolving 1 gram of sodium sulfite in 1 liter of deionized water. This should be made fresh weekly or as needed. If the unit is equipped with a wiper, it should be removed before immersing in zero-DO solution. The reading should not exceed a concentration of 0.2 mg/l dissolved oxygen in the zero-DO solution. For Clark cells that exceed this concentration, replace the electrolyte and membrane before repeating the zero-DO verification process. For optical probes that read above 0.2 mg/l in zero-DO solution, replace the sensor cap if it is expired or perform a 2- point calibration if applicable. Some optical DO probes are capable of 2-point calibrations using a zero-DO solution and the air-saturated water method discussed in Section 3.2.2. Refer to the manufacturer’s instruction manual for the appropriate 2-point calibration procedure. Ensure that the probe is thoroughly rinsed of zero-DO solution after verification or calibration to avoid measurement interferences caused by residual sodium sulfite.” Section 3.4: Changed the fifth bullet point to read “The DO meter should be capable of auto-correcting for specific conductivity/salinity or a separate instrument should be used to measure specific conductivity/salinity so that the final DO measurement(s) can be corrected.” Section 3.5: Changed the title from “Operational Check” to “Operational Verification.” Changed first paragraph to read “A post-calibration and post-operation instrument verification check should be performed using one of the techniques described in Sections 3.2.1 and 3.2.2 or 3.2.3 (for 2-point calibrations) to quantify potential instrument drift during use. A verification check will be performed after a calibration and at the end of all measurements” Changed second paragraph to read “It may be appropriate to verify the calibration of a DO meter periodically during the course of a day’s measurements when conducting individual measurements. A DO probe may be re-calibrated throughout the day if drift is occurring. The verification DO concentration should be measured and recorded in the field logbook prior to any instrument adjustment.” Also added the sentence “For long-term deployments a post-operation verification should be performed at the end of the deployment.” Added third paragraph which reads “Verification is done by comparing a post-calibration or post-operation reading at 100% saturation conditions to a DO solubility table value at the ambient air/water temperature and barometric pressure. Post-calibration and post- operation readings should not exceed a maximum of ± 0.2 mg/l from the DO solubility table value. DO solubility tables can be accessed via the U.S. Geological Survey’s DOTABLES software (USGS, 2013b) which are based on equations from Benson and Krause (1980; 1984).” calibration and postcalibration and post instrument verification check should be performed using one of the instrument verification check should be performed using one of the s described in Sections 3.2.1 and 3.2.2 or 3.2.3 (for 2s described in Sections 3.2.1 and 3.2.2 or 3.2.3 (for 2 calibrations) to quantify potential instrument drift during use. A calibrations) to quantify potential instrument drift during use. A verification check will be performed after a calibration and at the end verification check will be performed after a calibration and at the end Changed second paragraph to readChanged second paragraph to read “ “It may be appropriate to verify the It may be appropriate to verify the calibration of a DO meter periodically during the course of a day’s calibration of a DO meter periodically during the course of a day’s measurements when conducting individual measurements. A DO probe measurements when conducting individual measurements. A DO probe calibrated throughout the day if drift is occurring. The calibrated throughout the day if drift is occurring. The ncentration should be measured and recorded in the ncentration should be measured and recorded in the Changed the title from “Operational Check” to Changed the title from “Operational Check” to Field Measurement of DO Effective Date: April 9, 2021 Approved by ESS Chief Page 12 of 12 LSASDPROC-106-R4 040921 SESDPROC-106-R3, Field Measurement of Dissolved Oxygen, replaces SESDPROC-106-R2 . January 8, 2014 SESDPROC-106-R2, Field Measurement of Dissolved Oxygen, replaces SESDPROC-106-R1 February 12, 2010 SESDPROC-106-R1, Field Measurement of Dissolved Oxygen, replaces SESDPROC-106-R0 November 1, 2007 SESDPROC-106-R0, Field Measurement of Dissolved Oxygen, Original Issue February 05, 2007 Note: Section references in this Table made prior to April 2021 are from the old SOP format. Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field Measurement of Oxidation- Reduction Potential ID: LSASDPROC-113-R3 Issuing Authority: Chief, Field Services Branch Effective Date: December 17, 2021 Next Review Date: December 17, 2025 Method Reference: NA Author: Malcolm Grieve Purpose This document describes procedures, methods and considerations to be used and observed when conducting field Oxidation-Reduction Potential (ORP) measurements in aqueous environmental media, including groundwater, surface water and certain wastewater. The measurement of soil ORP is a non-standard measurement and procedures should be developed on a project-specific basis. While this SOP may be informative for other businesses, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Scope/Application This document describes procedures generic to all ORP measurement methods to be used by Laboratory Services and Applied Science Division (LSASD) field personnel when collecting and handling samples in the field. On the occasion LSASD personnel determine that any of the procedures described in this section are inappropriate, inadequate, or impractical and that another procedure must be used to obtain an ORP measurement, the variant procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Note: LSASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, signatures, SOPs, and forms as they are developed, which will also be housed on the Local Area Network (LAN) and traceable to each project. Author: Malcolm GrieveAuthor: Malcolm Grieve his document describes procedures, methods and considerations to be used and his document describes procedures, methods and considerations to be used and conducting field Oxidation-Reduction Potential (ORP) measurements in aqueous environmental conducting field Oxidation-Reduction Potential (ORP) measurements in aqueous environmental media, including groundwater, surface water and certain wastewater. The measurement of soil media, including groundwater, surface water and certain wastewater. The measurement of soil ORP is a non-standard measurement and procedures should be developed on a project-ORP is a non-standard measurement and procedures should be developed on a project- While this SOP may be informative for other businesses, it is not intended for and may While this SOP may be informative for other businesses, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or not be directly applicable to operations in other organizations. Mention of trade names or g procedure does not constitute endorsement or g procedure does not constitute endorsement or his document describes procedures generic to all ORP measurement methods to be used by his document describes procedures generic to all ORP measurement methods to be used by Laboratory Services and Applied Laboratory Services and Applied handling samples in the field. On the occasion handling samples in the field. On the occasion procedures described in this section are inappropriate, procedures described in this section are inappropriate, procedure must be used to obtain an ORP measurementprocedure must be used to obtain an ORP measurement documented in the field logbook, along with a description of the circumstances requiring its use. TABLE OF CONTENTS 1. General Information _______________________________________________________ 3 1.1. Documentation/Verification _____________________________________________ 3 1.2. General Considerations _________________________________________________ 3 2. Background ______________________________________________________________ 5 2.1. General _____________________________________________________________ 5 2.2. Instrumentation _______________________________________________________ 6 Figure 1: Hydrogen Half-Cell ____________________________________________________ 6 Figure 2: SHE connected with a salt bridge to a second half-cell ________________________ 7 Figure 3: SHE is connected to an Ag/AgCl electrode _________________________________ 8 Table 1: Half-cell Potential of Ag/AgCl Reference ___________________________________ 8 Figure 4: Relationship between a hydrogen electrode, a reference electrode, and a platinum sensing electrode ______________________________________________________________ 9 Figure 5: Separate Electrochemical Cells __________________________________________ 10 Figure 6: Practical Field Instrument ______________________________________________ 11 2.3. Redox Chemistry ____________________________________________________ 11 2.4. Applications ________________________________________________________ 13 2.5. Limitations _________________________________________________________ 14 3. Methodology ____________________________________________________________ 15 3.1. Standard Solutions ___________________________________________________ 15 3.2. Verification and Calibration ____________________________________________ 16 3.3. Measurement ________________________________________________________ 18 3.4. Reporting___________________________________________________________ 19 Table 1: Half-Cell Potential of Ag/AgCl Reference __________________________________ 19 References __________________________________________________________________ 21 Revision History _____________________________________________________________ 22 ____________________ 6____________________ 6 ________________________ 7 ________________________ 7 ________________________________________________________________ ________________________________________________________________ Figure 4: Relationship between a hydrogen electrode, a reference electrode, and a platinum Figure 4: Relationship between a hydrogen electrode, a reference electrode, and a platinum ______________________________________________________________ 9______________________________ 9________________________________ __________________________________________ 10 __________________________________________ 10 ______________________________________________ 11 ______________________________________________ 11 2.3. Redox Chemistry ____________________________________________________ 112.3. Redox Chemistry ____________________________________________________ 11 2.4. Applications ________________________________________________________ 132.4. Applications ________________________________________________________ 13 _________________________________________________________ 14 _________________________________________________________ 14 3. Methodology ____________________________________________________________ 153. Methodology ____________________________________________________________ 15 3.1. Standard Solutions ___________________________________________________ 153.1. Standard Solutions ___________________________________________________ 15 Verification and CalibrationVerification and Calibration MeasurementMeasurement ________________________________________________________ 18 ________________________________________________________ 18 3.4. Reporting___________________________________________________________ 193.4. Reporting___________________________________________________________ 19 Procedural Section 1. General Information 1.1. Documentation/Verification 1.1.1. This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD local area network (LAN). The Document Control Coordinator (DCC) is responsible for ensuring the most recent version of the procedure is placed on the LSASD LAN and for maintaining records of review conducted prior to its issuance. 1.2. General Considerations 1.2.1. Safety 1.2.1.1. Proper safety precautions must be observed when verifying or calibrating instruments for measurement of Oxidation-Reduction Potential. Refer to the EPA Region 4. Region 4 Safety & Occupational Heal SharePoint Site: https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%2 0and%20Resources.aspx and any pertinent site-specific Health and Safety Plans (HASP) for guidelines on safety precautions. These guidelines should be used to complement the judgment of an experienced professional. 1.2.1.2. Reagents commonly used in the preparation of ORP calibration standards are toxic and require care when handling. When using this procedure, avoid exposure to these materials through the use of protective clothing, eye wear and gloves. Safety precautions when handling and preparing verification solutions should include gloves and eyewear to prevent dermal and eye contact, and a mask to avoid inhaling dust particles when handling dry materials. Vigorous flushing should be used if the reagents or solutions come in contact with skin or eyes. Following is specific information on commonly used solutions. The application of the solutions is described in detail in Section 3.1, Standard Solutions, of this procedure. Quinhydrone (CAS# 106-34-3) is a skin and respiratory irritant and is poisonous if ingested. Safety precautions when handling quinhydrone should include gloves to prevent dermal contact and a mask to avoid inhaling dust particles when mixing dry material to prepare calibration standards. Vigorous flushing should be used if concentrated material comes in contact with skin or eyes. precautions must be observed when verifying or calibrating precautions must be observed when verifying or calibrating instruments for measurement of Oxidation-Reduction Potential. Refer to the instruments for measurement of Oxidation-Reduction Potential. Refer to the Region 4 Safety & Occupational Heal SharePoint Site:Region 4 Safety & Occupational Heal SharePoint Site: https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%2https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%2 0and%20Resources.aspx and any pertinent site-and any pertinent site-specific Health and Safespecific Health and Safe on safety precautions. These guidelines should be used to complement the on safety precautions. These guidelines should be used to complement the judgment of an experienced professional. judgment of an experienced professional. Reagents cReagents commonly used in the preparation of ORP calibration standards ommonly used in the preparation of ORP calibration standards are toxic and require care when handling. When using this procedure, avoid are toxic and require care when handling. When using this procedure, avoid exposure to exposure to and gloves. Safety precautions when handling and preparing and gloves. Safety precautions when handling and preparing solutions should include gloves solutions should include gloves Zobell’s solution is also an irritant and toxic if ingested. The same handling precautions apply when mixing and using Zobell’s solution as when using quinhydrone. Zobell’s reacts with acid to form harmful byproducts, including hydrocyanide gas. Light’s solution contains ferro- and ferric-cyanide compounds in sulfuric acid. The components are toxic and burns are possible from contact with this solution. Potassium iodide solutions have lower toxicity than most calibration solution options. General ingestion, skin contact, and eye contact precautions apply. 1.2.1.3. Unused quinhydrone, Zobell’s, Light’s or other calibration reagents and solutions should be returned to LSASD for disposal in accordance with the LSASD Safety, Health, and Environmental Management Plan (SHEMP). 1.2.2. Records 1.2.2.1. Documentation of field activities is done in a bound logbook. All records, including a unique, traceable identifier for the instrument, should be entered according to the procedures outlined in the Sample and Evidence Management (LSASDPROC-005-R4) and the LSASD Operating Procedure for Equipment Inventory and Management, (LSASDPROC-108, most recent version). 1.2.2.2. All field ORP measurements pertinent to the sampling event should be recorded in the field logbook for the event as outlined in the Sample and Evidence Management (LSASDPROC-005-R4) or managed electronically with appropriate backups as described in LSASD Operating Procedure for Control of Records (LSASDPROC-002, most recent version). 1.2.3. Shipping 1.2.3.1. Shipped material shall conform to all U.S. Department of Transportation (DOT) rules of shipment found in Title 49 of the Code of Federal Regulations (49 CFR parts 171 to 179), and/or International Air Transportation Association (IATA) hazardous materials shipping requirements found in the current edition of IATA’s Dangerous Goods Regulations. 1.2.3.2. All shipping documents, such as bills of lading, will be retained by the project leader and stored in a secure place. , Light’s or other calibrationcalibration for disposal for disposal in accordance in accordance Safety, Health, and Environmental Management Plan (SHEMP). Safety, Health, and Environmental Management Plan (SHEMP). Documentation of field activities is done in a bound logbook. All records, Documentation of field activities is done in a bound logbook. All records, including a unique, traceable identifier for the instrument, should be entered including a unique, traceable identifier for the instrument, should be entered to the procedures outlined in the to the procedures outlined in the ) and the ) and the LSASDLSASD Inventory and Management, (Inventory and Management, (LSASDLSASD All field ORP measurements pertinent to the sampling event should be All field ORP measurements pertinent to the sampling event should be recorded in the field logbook for the event as outlined in the recorded in the field logbook for the event as outlined in the Evidence Management (LSASDPROCEvidence Management (LSASDPROC with appropriate backups as described in with appropriate backups as described in Control of Records (Control of Records ( Shipping Shipping 2. Background 2.1. General 2.1.1. Oxidation is the process of liberating electrons or gaining oxygen. Examples of oxidation include conversion of elemental iron to rust, elemental sulfur to sulfate, and elemental hydrogen to water (Pankow 1991). Reduction is the process of gaining electrons resulting in the charge on some atomic unit in the species to be reduced. Oxidation-reduction potential (ORP) or redox potential (hereafter, referred to as redox) is a measure of the intensity or activity of an aqueous environment or soil to mediate reactions of important elements in biological systems (e.g., O, N, Mn, Fe, S, and C) and other metallic elements. 2.1.2. Considerable confusion arises on the use of the terms oxidation and reduction as they apply to the media under study. The following introduction reproduced from an online ‘Wikipedia’ article on the topic lucidly explains their relationship in ORP measurement: 2.1.2.1. Reduction potential (also known as redox potential, oxidation / reduction potential or ORP) is the tendency of a chemical species to acquire electrons and thereby be reduced. Each species has its own intrinsic reduction potential; the more positive the potential, the greater the species' affinity for electrons and tendency to be reduced. 2.1.2.2. In aqueous solutions, the reduction potential is the tendency of the solution to either gain or lose electrons when it is subject to change by introduction of a new species. A solution with a higher (more positive) reduction potential than the new species will have a tendency to gain electrons from the new species (i.e., to be reduced by oxidizing the new species) and a solution with a lower (more negative) reduction potential will have a tendency to lose electrons to the new species (i.e., to be oxidized by reducing the new species). Just as the transfer of hydrogen ions between chemical species determines the pH of an aqueous solution, the transfer of electrons between chemical species determines the reduction potential of an aqueous solution. Like pH, the reduction potential represents an intensity factor. It does not characterize the capacity of the system for oxidation or reduction, in much the same way that pH does not characterize the buffering capacity. 2.1.3. In short, a numerically positive redox potential or ORP represents an environment conducive to the oxidation of an introduced substance by reduction of the original media. Considerable confusion arises on the use of the terms oxidation and reduction Considerable confusion arises on the use of the terms oxidation and reduction they apply to the media under study. The following introduction reproduced from an they apply to the media under study. The following introduction reproduced from an online ‘Wikipedia’ article on the topic lucidly explains theonline ‘Wikipedia’ article on the topic lucidly explains theiriririr (also known as (also known as redox potential, oxidation / redox potential, oxidation / ) is the tendency of a ) is the tendency of a reducedreduced. Each species has its own intrinsic reduction . Each species has its own intrinsic reduction potential; the more positive the potential, the gpotential; the more positive the potential, the g electrons and tendency to be reduced. electrons and tendency to be reduced. In aqueous solutions, the reduction potential is the tendency of the solution In aqueous solutions, the reduction potential is the tendency of the solution to either gain or lose electrons when it is subject to change by introduction of a to either gain or lose electrons when it is subject to change by introduction of a new species. A solution with a higher (more positive) reduction potential than new species. A solution with a higher (more positive) reduction potential than the new species will have a tendency to gain electrons from the new species the new species will have a tendency to gain electrons from the new species (i.e., to be reduced by oxidizing the new species) and a solution with a lower (i.e., to be reduced by oxidizing the new species) and a solution with a lower (more negative) reduction potential will have(more negative) reduction potential will have the new species (the new species ( transfer of hydrogen ions between chemical species determines the pH of an transfer of hydrogen ions between chemical species determines the pH of an aqueous solution, the transfer of electrons between chemical species aqueous solution, the transfer of electrons between chemical species determines the reduction potential of an aqueous solution. Like pH, the 2.2. Instrumentation 2.2.1. ORP measurement systems are a practical implementation of electrochemical cells, which use metal electrodes in a solution to generate an electric current or voltage. If a platinum electrode is immersed in water with hydrogen bubbled into the solution, the H2 is oxidized as follows: = 2 + 2 2.2.2. In the electrochemical half-cell illustrated below in Fig.1, hydrogen gas oxidizes to hydrogen ions and free electrons, comprising an oxidation-reduction couple. This couple reaches an equilibrium state that maintains the reference potential of the electrode. The electric potential develops on the wire connected to the platinum electrode but is difficult to measure in practice in the isolated half-cell. However, when used in a complete electrochemical cell, the cell illustrated is used as a reference to measure other half-cells against and is called a Standard Hydrogen Electrode (SHE). Figure 1: Hydrogen Half-Cell 2.2.3. If, as shown in Figure 2, a SHE is connected with a salt bridge to a second half- cell in which a reduction reaction is taking place, the electric potential between the two cells can be measured. In the case shown, the potential of the right cell will be +0.34 Volts in reference to the standard hydrogen electrode on the left. This would be represented as an Oxidation Reduction Potential (ORP) of +340mV on the hydrogen scale, or simply as Eh = +340mV. illustrated below in Fig.1, hydrogen illustrated below in Fig.1, hydrogen to hydrogen ions and free electrons, comprising an oxidation-reduction couple. This to hydrogen ions and free electrons, comprising an oxidation-reduction couple. This couple reaches an equilibrium state that maintains the reference potential of the couple reaches an equilibrium state that maintains the reference potential of the electric potential develops on the wire connected to the platinum electric potential develops on the wire connected to the platinum fficult to measure in practice in the isolated halffficult to measure in practice in the isolated half when used in a complete electrochemical cell, the cellwhen used in a complete electrochemical cell, the cell illustrated is usedillustrated is used cells against and is called is called Figure 2: SHE connected with a salt bridge to a second half-cell 2.2.4. In field practice, the hydrogen electrode is difficult to reproduce. To conduct field measurements, a reference electrode is needed that is simple to maintain and will generate a potential that can be referenced to the standard hydrogen electrode. These requirements are met by the Saturated Calomel Electrode (SCE) and the Silver/Silver Chloride Electrode (SSCE - the SSCE is also commonly identified as an Ag/AgCl electrode). The SCE contains a small amount of elemental mercury, and while useful for certain applications, would rarely be used at LSASD. The SSCE or Ag/AgCl electrode is generally used as the reference cell in LSASD instrumentation. 2.2.5. In Figure 3 below, a SHE is connected to an Ag/AgCl electrode. In this example of an electrochemical cell, both cells reach an equilibrium potential. At that equilibrium state, the potential of the Ag/AgCl cell is 220mV more positive than the standard hydrogen electrode. field practice, the hydrogen electrode is difficult to reproduce. To conduct field field practice, the hydrogen electrode is difficult to reproduce. To conduct field measurements, a reference electrode is needed that measurements, a reference electrode is needed that generate a potential that can be referenced to the standard hydrogengenerate a potential that can be referenced to the standard hydrogen These requirements are met by the Saturated Calomel Electrode (SCE) and the These requirements are met by the Saturated Calomel Electrode (SCE) and the Silver/Silver Chloride Electrode (SSCESilver/Silver Chloride Electrode (SSCE an Ag/AgCl electrodean Ag/AgCl electrode and while useful for certain applications, would rarely be and while useful for certain applications, would rarely be SSCE or Ag/AgCl electrode is generally used as the reference cell in SSCE or Ag/AgCl electrode is generally used as the reference cell in instrumentation.instrumentation. Figure 3: SHE is connected to an Ag/AgCl electrode 2.2.6. This half-cell potential of the Ag/AgCl electrode in reference to the SHE is used to convert measurements taken with an Ag/AgCl reference back to the hydrogen scale. While the laboratory Ag/AgCl half-cell shown has a potential of +220mV, practical reference cells have varying potentials based on temperature and filling solutions as shown in Table 1 below. Table 1: Half-cell Potential of Ag/AgCl Reference Molarity of KCl filling solution T(°C) 3M 3.3M* 3.5M Sat/4M 10 220 217 215 214 15 216 214 212 209 20 213 210 208 204 25 209 207 205 199 30 205 203 201 194 35 202 199 197 189 40 198 195 193 184 *interpolated value derived from USGS NFM, Table 6.5.2 (9/2005) This half-cell potential of the Ag/AgCl electrode in reference to the SHE is used This half-cell potential of the Ag/AgCl electrode in reference to the SHE is used nvert measurements taken with an Ag/AgCl reference back to the hydrogen nvert measurements taken with an Ag/AgCl reference back to the hydrogen . While the laboratory Ag/AgCl half-e laboratory Ag/AgCl half- practical reference cells have varying potentials based on temperature and filling practical reference cells have varying potentials based on temperature and filling ns as shown in Table 1 below. ns as shown in Table 1 below. Table 1Table 1 Note: YSI sondes and Thermo electrodes typically use 4M KCl filling solutions. Eureka sondes typically use 3.3M KCl filling solutions. 2.2.7. In Figure 4, below, the relationship between a hydrogen electrode, a reference electrode, and a platinum sensing electrode in an arbitrary media is shown. In this case, the ORP of the media in reference to the silver/silver chloride electrode is 150mV. To obtain Eh, the potential of the reference electrode in relation to a hydrogen electrode is added to the potential of the sensing electrode in relation to the reference electrode. In practice, the potential of the reference electrode in relation to a hydrogen electrode is not measured but obtained from Table 1 above. Figure 4: Relationship between a hydrogen electrode, a reference electrode, and a platinum sensing electrode In Figure 5 below, a field instrument is represented as separate electrochemical cells. The Ag/AgCl reference electrode uses a ceramic frit or other means to provide the essential salt bridge to the environmental media. The platinum sensing electrode is immersed in the environmental media and connected internally in the instrument to measure the potential (voltage) between the two electrodes. elationship between a hydrogen electrode, a reference electrode, elationship between a hydrogen electrode, a reference electrode, Figure 5: Separate Electrochemical Cells In this illustration, the ORP is measured as 340 mV. This measurement is made in reference to the Ag/AgCl reference electrode and would be reported as such, or as EAg/AgCl = 340mV. 2.2.8. In some cases it will be desirable to report the reading on the hydrogen scale, or Eh. To do so, the potential of the reference electrode against the SHE, obtained from Table 1, is added to EAg/AgCl. For our example: 340 mV Measured ORP (EAg/AgCl) of sample + 204 mV Eh of Ag/AgCl electrode (ORP of Ag/AgCl electrode referenced to SHE) 544 mV Eh of sample 2.2.9. Both the +340 mV field reading and the adjusted +544 mV Eh can properly be referred to as ORP results. It is only through specifying the reference scale that the ambiguity can be eliminated. 2.2.10. In Figure 6, below, the theoretical cells shown above have been configured as a practical field instrument. The salt bridge is commonly provided by a ceramic frit connecting the environmental media to the reference electrode. In multi-parameter sondes, the pH probe commonly uses the same reference electrode as the ORP probe. the ORP is measured asthe ORP is measured as reference to the Ag/AgCl reference electrode and would be reported as such, or as reference to the Ag/AgCl reference electrode and would be reported as such, or as some cases it will be desirable to report the reading on the hydrogen scale, or it will be desirable to report the reading on the hydrogen scale, or Eh. To do so, the potential of Eh. To do so, the potential of Table 1, is added to EAg/AgCl. For our example: , is added to EAg/AgCl. For our example: 340 mV 340 mV Measured ORP (EMeasured ORP (E mVmV Figure 6: Practical Field Instrument 2.3. Redox Chemistry 2.3.1. In acid-base chemistry, the pH of a system is defined as the negative logarithm of the hydrogen ion activity (simplified in practice to the hydrogen ion concentration): = {} 2.3.2. Similarly, Pankow (1991) described the negative logarithm of the electron activity (pe) as the master variable for describing the equilibrium position for all redox couples in a given system: {} Redox Chemistry In acidIn acid-base chemistry, the pH of a system is defined as the negative logarithm of -base chemistry, the pH of a system is defined as the negative logarithm of the hydrogen ion activity (simplified in practice to the hydrogen ion concentration): the hydrogen ion activity (simplified in practice to the hydrogen ion concentration): 2.3.3. It can be shown (Pankow) that pe is related to Eh by = (2.303 ) Where: R = gas constant = 8.314 J K-1 mol-1 T = temperature, oK F = Faraday constant = 96.485*103 C mol-1 At 25°C (298°K) this simplifies to: = 0.05916 and, = 0.05916 2.3.4. According to Faulkner et al. (1989) redox is a quantitative measure of electron availability and is indicative of the intensity of oxidation or reduction in both chemical and biological systems. When based on a hydrogen scale, redox (EH) is derived from the Nernst Equation (Stumm and Morgan 1981): = + 2.3 (){}{} Where: EHo = potential of reference, mV R = gas constant = 81.987 cal deg-1 mole-1 T = temperature, oK n = number of moles of electrons transferred F = Faraday constant = 23.061 cal/mole-mv {ox} and {red} = activity of the oxidants and reductants, respectively derived from the Nernst Equation (Stumm and Morgan 1981): derived from the Nernst Equation (Stumm and Morgan 1981): ( ( = potential of reference, mV= potential of reference, mV R = gas constant = 81.987 cal degR = gas constant = 81.987 cal deg T = temperature, oKT = temperature, oK n = number of moles of electrn = number of moles of electr According to Faulkner et al. (1989) redox is a quantitative measure of electron According to Faulkner et al. (1989) redox is a quantitative measure of electron availability and is indicative of the intensity of oxidation or reduction in both availability and is indicative of the intensity of oxidation or reduction in both chemical and biological systems. When based on a hydrogen scale, redox (Echemical and biological systems. When based on a hydrogen scale, redox (E derived from the Nernst Equation (Stumm and Morgan 1981): derived from the Nernst Equation (Stumm and Morgan 1981): 2.4. Applications 2.4.1. When interpreted properly, redox combined with other conventional water quality parameters is useful in developing a more complete understanding of water chemistry. Several applications of redox are identified below: 1. Redox could be viewed as an extension of the oxygen scale. In this model, the DO probe spans the aerobic scale and the redox probe extends that scale to measure anaerobic conditions. Inferences to geochemistry and chemical speciation can be made from the oxidative state of the system. Application to metal sequestration, metal-iron, -sulfide, -methane complexation, and the subsequent bioaccumulation potential is possible. 2. Redox can be used to identify anaerobiosis at or near the water column and sediment interface in streams, lakes, and estuaries. 3. Redox may be useful in determination of stream jurisdiction and wetland delineation in that it can indicate conditions of soil saturation. 4. Based on redox, a pe (or EH) vs. pH stability diagram can be developed to aid in nutrient exchange studies including the timing, release, and partitioning of important water and sediment quality pollutants such as nitrogen and phosphorus species. Most importantly, redox can be used to address error associated with chamber-effect during closed chamber measurements of the water-sediment interface. Redox probes placed inside the contact chamber and inserted approximately ten centimeters into the underlying sediment can be used to monitor changes in sediment redox caused by the chamber, and steps can be taken to reduce chamber-effect. 5. Redox may be useful in establishing water and sediment quality standards applicable to wetlands. 6. Redox is used to assess the potential of a groundwater system to support various in situ reactions with contaminants, such as reductive dechlorination of chlorinated solvents. 7. Redox can provide a useful indicator of conditions that might compromise the performance of Clark-type dissolved oxygen (DO) probes. In general, anaerobic conditions occur at a redox range of +150 mV to +300 mV (pH- dependent and adjusted to hydrogen reference electrode). When redox drops below this level, DO measurements as determined with a Clarke-type probe are highly suspect as the semi-permeable membrane does not discriminate between partial O2 and sulfides. Consequently, the meter may be reading sulfides. the contact chamber and inserted approximately ten centimeters into the the contact chamber and inserted approximately ten centimeters into the underlying sediment can be used to monitor changes in sediment redox underlying sediment can be used to monitor changes in sediment redox caused by the chamber, and steps can be caused by the chamber, and steps can be Redox may be useful Redox may be useful in establishing water and sediment quality standin establishing water and sediment quality stand applicable to wetlands.applicable to wetlands. Redox is used to assess the potential of a groundwater system to support Redox is used to assess the potential of a groundwater system to support various inin situ situ reactions with contaminants, such as red of chlorinated solvents. of chlorinated solvents. Redox can provide a useful indicator of conditions that might compromise Redox can provide a useful indicator of conditions that might compromise the performance of Clarkthe performance of Clark anaerobic conditions occur at a redox range of +150 mV to +300 anaerobic conditions occur at a redox range of +150 mV to +300 dependent and adjusted to hydrogen reference electrode). When redox aid in nutrient exchange studies including the timing, release, and partitioning of important water and sediment quality pollutants such as partitioning of important water and sediment quality pollutants such as nitrogen and phosphorus species. Most importantly, redox can be used to nitrogen and phosphorus species. Most importantly, redox can be used to address error associated with chamberaddress error associated with chamber-effect during closed chamber easurements of the watereasurements of the water-sediment interface. Redox probes placed inside -sediment interface. Redox probes placed inside the contact chamber and inserted approximately ten centimeters into the the contact chamber and inserted approximately ten centimeters into the Redox can be used to identify anaerobiosis at or near the water column and Redox can be used to identify anaerobiosis at or near the water column and streams, lakes, and estuaries. in determination of stream jurisdin determination of stream jurisdiction and wetland iction and wetland in that it can indicate conditions of soil saturation.in that it can indicate conditions of soil saturation. Based on redox, a pe (or EH) vs. pH stability diagram can be developed to Based on redox, a pe (or EH) vs. pH stability diagram can be developed to aid in nutrient exchange studies including the timing, release, and aid in nutrient exchange studies including the timing, release, and partitioning of important water and sediment quality pollutants such as 2.5. Limitations 2.5.1. In most environmental media, redox reactions will not reach equilibrium due to low concentrations or multiple redox species. Consequently, redox measurements can generally be considered semi-quantitative in environmental media, unless certain conditions exist. 2.5.2. The USGS in the Interferences and Limitations Section 6.5.3A of their National Field Manual succinctly describe some of the issues encountered in the application of ORP measurements. This section is reproduced here, unedited: 2.5.2.1. INTERFERENCES AND LIMITATIONS 2.5.2.1.1. Measurements should not be carried out without an awareness of the interferences and limitations inherent in the method. Organic matter and sulfide may cause contamination of the electrode surface, salt bridge, or internal electrolyte, which can cause drift or erratic performance when reference electrodes are used (American Public Health Association and others, 2001). Hydrogen sulfide can produce a coating on the platinum electrode that interferes with the measurement if the electrode is left in sulfide- rich water for several hours (Whitfield, 1974; Sato, 1960). The platinum single and combination redox electrodes may yield unstable readings in solutions containing chromium, uranium, vanadium, or titanium ions and other ions that are stronger reducing agents than hydrogen or platinum (Orion Research Instruction Manual, written commun., 1991). Do not insert redox electrodes into iron-rich waters directly after the electrode(s) contact ZoBell’s. An insoluble blue precipitate coats the electrode surface because of an immediate reaction between ferro- and ferricyanide ions in ZoBell’s with ferrous and ferric ions in the sample water, causing erratic readings. Many elements with more than one oxidation state do not exhibit reversible behavior at the platinum electrode surface and some systems will give mixed potentials, depending on the presence of several different couples (Barcelona and others, 1989; Bricker, 1982, p. 59–65; Stumm and Morgan, 1981, p. 490–495; Bricker, 1965, p. 65). Methane, bicarbonate, nitrogen gas, sulfate, and dissolved oxygen generally are not in equilibrium with platinum electrodes (Berner, 1981). that interferes with the measurement if the electrode is left in sulfidethat interferes with the measurement if the electrode is left in sulfide rich water for several hours (Whitfield, 1974; Sato, 1960). rich water for several hours (Whitfield, 1974; Sato, 1960). The platinum single and combination redox electrodes may yield The platinum single and combination redox electrodes may yield unstable readings in solutions containing chromium, uranium, unstable readings in solutions containing chromium, uranium, vanadium, or titanium ions and other ions that are stronger reducing vanadium, or titanium ions and other ions that are stronger reducing agents than hydrogen or platinum (Orion Research Instruction agents than hydrogen or platinum (Orion Research Instruction Manual, written commun., 1991). Manual, written commun., 1991). electrode surface, salt bridge, or internal electrolyte, which can cause drift or erratic performance when reference electrodes are cause drift or erratic performance when reference electrodes are used (American Public Health Association and others, 2001). used (American Public Health Association and others, 2001). Hydrogen sulfide can produce a coating on the plaHydrogen sulfide can produce a coating on the pla that interferes with the measurement if the electrode is left in sulfidethat interferes with the measurement if the electrode is left in sulfide Measurements should not be carried out without an awareness of Measurements should not be carried out without an awareness of the interferences and limitations inherent in the method. the interferences and limitations inherent in the method. Organic matter and sulfide may cause contamination of the Organic matter and sulfide may cause contamination of the electrode surface, salt bridge, or internal electrolyte, which can electrode surface, salt bridge, or internal electrolyte, which can 2.5.2.2. Technical Note: Misconceptions regarding the analogy between Eh (pe) and pH as master variables and limitations on the interpretation of Eh measurements are explained in Hostettler (1984), Lindberg and Runnells (1984), Thorstenson (1984), and Berner (1981). To summarize: (1) Hydrated electrons do not exist in meaningful concentrations in most aqueous systems—in contrast, pH represents real activities of hydrated protons. Eh may be expressed as pe (the negative logarithm of the electron activity), but conversion to pe offers no advantage when dealing with measured potentials. (2) Do not assume that redox species coexist in equilibrium. Many situations have been documented in which dissolved oxygen coexists with hydrogen sulfide, methane, and ferrous iron. The practicality of Eh measurements is limited to iron in acidic mine waters and sulfide in waters undergoing sulfate reduction. Other redox species are not sufficiently electroactive to establish an equilibrium potential at the surface of the conducting electrode. (3) A single redox potential cannot be assigned to a disequilibrium system, nor can it be assigned to a water sample without specifying the particular redox species to which it refers. Different redox elements (iron, manganese, sulfur, selenium, arsenic) tend not to reach overall equilibrium in most natural water systems; therefore, a single Eh measurement generally does not represent the system. 3. Methodology 3.1. Standard Solutions 3.1.1. Care should be taken not to contaminate standards and samples and to verify the expiration date of all standards prior to use. All meters should be verified or calibrated according to the manufacturer’s procedures. 3.1.2. Standard solutions for calibration and verification should be selected to meet project requirements. LSASD generally maintains a stock of Zobell’s solution suitable for most projects. The characteristics and use of the common standard solutions are described below. Zobell’s solution contains potassium ferri- and ferro- cyanide compounds. The solution is available as prepared solutions or premeasured reagents for mixing by the user. Zobell’s has moderate toxicity but will react with acid to form harmful byproducts, including hydrocyanide gas. It has a shelf life system, nor can it be assigned to a water sample without specifying the system, nor can it be assigned to a water sample without specifying the particular redox species to which it refers. Different redox elements particular redox species to which it refers. Different redox elements (iron, manganese, sulfur, selenium, arsenic) tend not to reach overall (iron, manganese, sulfur, selenium, arsenic) tend not to reach overall equilibrium in most natural water systems; therefore, a single Eh equilibrium in most natural water systems; therefore, a single Eh measurement generally does not represent the system.measurement generally does not represent the system. Standard Solutions Standard Solutions Care should be taken not to contaminate standards and samples and to verify the Care should be taken not to contaminate standards and samples and to verify the Other redox species are not sufficiently electroactive to Other redox species are not sufficiently electroactive to establish an equilibrium potential at the surface of the establish an equilibrium potential at the surface of the conducting electrode. conducting electrode. A single redox potential cannot be assigned to a disequilibrium A single redox potential cannot be assigned to a disequilibrium system, nor can it be assigned to a water sample without specifying the system, nor can it be assigned to a water sample without specifying the Do not assume that redox species coexist in equilibrium. Many Do not assume that redox species coexist in equilibrium. Many situations have been documented in which dissolved oxygen coexists situations have been documented in which dissolved oxygen coexists with hydrogen sulfide, methane, and ferrous iron. with hydrogen sulfide, methane, and ferrous iron. The practicality of Eh measurements is limitedThe practicality of Eh measurements is limited mine waters and sulfide in waters undergoing sulfate mine waters and sulfide in waters undergoing sulfate ranging from several days to several months depending on the manufacturer. Stock and working solutions of Zobell’s should be stored in dark bottles due to its light sensitivity. Quinhydrone solutions are mixed at the time of use by adding quinhydrone to pH 4 or pH 7 buffers. At 25°C, the Eh of quinhydrone pH 4 and pH 7 verification solutions are 462mV and 285mV respectively. An advantage of quinhydrone solutions is that they offer a span of calibration points that may be appropriate for particular applications. Quinhydrone is a lightly ‘poised’ solution in that it offers less driving force towards the calibration point: a compromised instrument is more likely to be revealed in a quinhydrone calibration. A quinhydrone calibration/verification solution is created by adding 10g of quinhydrone to 1L of pH 4 or pH 7 buffer solution (ASTM D1498). The solutions are mixed on a magnetic mixing plate for a minimum of 15 minutes to create a saturated solution with undissolved crystals remaining. Quinhydrone solutions are usable for 8 hrs from the time of mixing. Light’s solution consists of ferrous and ferric ammonium sulphate in sulphuric acid. The solution would rarely be used at LSASD due to its high acidity and associated handling difficulty. Spent solutions with a pH<2 would be regulated as a hazardous waste. Light’s is a highly poised solution that may allow a marginally functioning electrode to pass calibration. A prepared potassium iodide solution is available which has low toxicity and a long shelf life. The solution may stain clothing or surfaces if spilled. 3.2. Verification and Calibration 3.2.1. ORP instruments may be verified or calibrated, depending on the application. The approach chosen should be selected based on project needs and information presented in Section 2.4., Limitations. Standard laboratory practice in making ORP measurements is to verify the accuracy of the instrument prior to use, and this practice should be followed when true quantitative results are required. In a verification, the instrument in its direct-reading mode is checked against a standard solution in a pass/no-pass test, and no corrections are applied to subsequent measurements. In most applications, the ORP information is used semi- quantitatively and for these applications, the instruments may be calibrated to the standard solutions. In an instrument calibration, the instrument probe is placed in the standard solution and the difference between the standard measurement and the known ORP value of the standard is used by the instrument to make adjustments to the subsequent measurements. A prepared potassium iodide solution is available which has low toxicity A prepared potassium iodide solution is available which has low toxicity and a long shelf life. The solution may stain clothing or surfaces if spilled. and a long shelf life. The solution may stain clothing or surfaces if spilled. CalibrationCalibration ORP instruments may be ORP instruments may be The approach chosen should be selected based on project needs and information The approach chosen should be selected based on project needs and information presented in presented in Section Section measurements is to measurements is to practice should be followed when true quantitative results are required. practice should be followed when true quantitative results are required. Light’s solution consists of ferrous and ferric ammonium sulphate in Light’s solution consists of ferrous and ferric ammonium sulphate in sulphuric acid. The solution would rarely be used at sulphuric acid. The solution would rarely be used at acidity and associated handling difficulty. Spent solutions with a pH<2 acidity and associated handling difficulty. Spent solutions with a pH<2 would be regulated as a hazardous waste. Light’s is a highly poised solution would be regulated as a hazardous waste. Light’s is a highly poised solution that may allow a marginally functioning electrode to pass calibration. that may allow a marginally functioning electrode to pass calibration. 4 or pH 7 buffer solution (ASTM 4 or pH 7 buffer solution (ASTM D1498). The solutions are mixed on a magnetic mixing plate for a D1498). The solutions are mixed on a magnetic mixing plate for a minimum of 15 minutes to create a saturated solution with undissolved minimum of 15 minutes to create a saturated solution with undissolved crystals remaining. Quinhydrone solutions are usable for 8 hrs from the crystals remaining. Quinhydrone solutions are usable for 8 hrs from the Light’s solution consists of ferrous and ferric ammonium sulphate in Light’s solution consists of ferrous and ferric ammonium sulphate in 3.2.2. In verification of an ORP instrument, the instrument is set to absolute mV reading mode or the internal calibration offset is zeroed out. The instrument probe should then be placed in the standard solution and the reading verified to fall within +/-10mV of the predicted reading for the standard. Instruments with single-purpose electrodes are most suitable for this approach. If the instrument fails the verification, standard solution quality should be considered and instrument maintenance performed per the manufacturer’s procedures. 3.2.3. In most LSASD field practice, the end data use is semi-quantitative. In this case, the instruments can be calibrated to standard solutions appropriate for the project using the manufacturer’s recommended procedure. One minute after the calibration, the instrument should display a stable reading within +/-10mV of the predicted reading. An instrument failing this test should be recalibrated to determine if the problem is inadequate equilibration time. In the event of continued instrument failure, aging or contamination of the standard solution should be considered. Subsequently the electrode should be serviced according to the manufacturer’s procedures. Common service procedures include cleaning the platinum electrode with mild abrasives or acids and refilling or replacing the reference electrode. 3.2.4. Prior to a mobilization, all ORP instruments will be checked for proper operation and verified or calibrated against standard solutions. During the field mobilization, each instrument will be calibrated or verified prior to, and verified after, each day’s use or deployment. 3.2.5. Even though it is not necessary to re-calibrate ORP instrument at regular intervals during the day, it may be appropriate to occasionally perform operational checks to determine if site conditions, such as an extreme temperature change or submersion of a filling solution port have impacted the instrument’s performance. If an operational check is warranted, the field operator should follow the appropriate verification/calibration steps as described above. 3.2.6. The predicted ORP values of standard solutions will be obtained from the manufacturer of prepared solutions, literature, or appropriate values listed in this procedure. Care is in order, as the predicted ORP value is specific for the type of reference electrode used by the probe (either Ag/AgCl or calomel) and the molarity of the filling solution in the reference electrode. To use the solution with another electrode or filling solution, the expected ORP readings for the solution should be converted to Eh for the probes intended for the solution as per the Reporting section of this procedure. Then a table can be compiled for the electrode in use by subtracting the Eh,ref for the electrode and filling solution in use. This will be done at the Field Equipment Center (FEC) for the solutions stocked. Even though it is not necessary to re-Even though it is not necessary to re- during the day, it may be appropriate to occasionally perform operational checks to during the day, it may be appropriate to occasionally perform operational checks to determine if site conditions, such as an extreme temperature change or submersion determine if site conditions, such as an extreme temperature change or submersion of a filling solution port have impacted the instrument’s performance. If an of a filling solution port have impacted the instrument’s performance. If an operational check is warranted, the field operator should follow the appropriate operational check is warranted, the field operator should follow the appropriate verification/calibration steps as described above.verification/calibration steps as described above. The predicted ORP values of standard solutionThe predicted ORP values of standard solution manufacturer of prepared solutions, literature, or appropriate values listed manufacturer of prepared solutions, literature, or appropriate values listed procedure. Care is in order, with mild abrasives or acids and refilling or replacing the reference electrode. a mobilization, all ORP instrumentsa mobilization, all ORP instruments willwill standardstandard solutions. During the field mobilization, solutions. During the field mobilization, standardstandard or verified or verified within +/-10mV of the predicted within +/-10mV of the predicted ument failing this test should be recalibrated to determine if the to determine if the . In the event of continued . In the event of continued ging or contamination of the standard solution should be considered. ging or contamination of the standard solution should be considered. Subsequently the electrode should be serviced according to the manufacturer’s Subsequently the electrode should be serviced according to the manufacturer’s procedures. Common service procedures include cleaning the platinum electrode procedures. Common service procedures include cleaning the platinum electrode with mild abrasives or acids and refilling or replacing the reference electrode. with mild abrasives or acids and refilling or replacing the reference electrode. 3.2.7. Verification solutions should be managed per the manufacturer’s directions regarding storage and handling. After instrument verification or calibration, the solution cannot be returned to the stock solution container, although a separate container of working solution can be maintained. 3.2.8. Spent solutions and working solutions should be returned from the field to the LSASD laboratory for proper disposal by the SHEMP or handled as directed by the SHEMP. Properly handled stock solutions may be returned to the FEC for use at that facility. 3.3. Measurement 3.3.1. ORP measurements should be conducted in a fashion that prevents the addition or loss of any potential oxidants or reductants. Results could be compromised by exposing the sample to air or allowing H2S to off-gas from anoxic samples. Like dissolved oxygen measurements, ORP measurements should be conducted in situ or by using a flow-through cell evacuated of air (see the LSASD Operating Procedure for Field Measurement of Dissolved Oxygen (LSASDPROC-106-R4). Good results are commonly obtained with the use of an overtopping cell where the environmental media is pumped into the bottom of a narrow cup (generally field fabricated from a sample container) containing the instrument sensors. The sensors are continually flushed with fresh media as the cup is allowed to overflow. Caution should be exercised at very low flow rates where the media in the cup could potentially re- oxygenate. 3.3.2. When using multi-parameter probes for ORP measurements, the general guidelines for probe deployment described in the LSASD Operating Procedure for Field Measurement of Dissolved Oxygen ((LSASDPROC-106-R4) and the LSASD Operating Procedure for In-situ Water Quality Monitoring (LSASDPROC-111, most recent version) apply. 3.3.3. ORP probes must be operated and maintained in accordance with the manufacturer’s instructions. Reference electrodes in multi-parameter probes may require regular filling or replacement. Single parameter ORP electrodes may require regular filling and operation in an upright position to assure that proper salt bridge flow is maintained. Platinum electrode surfaces are easily contaminated and polishing, or cleaning of the electrodes should be performed as recommended by the manufacturer. 3.3.4. Measurements in field logbooks should be recorded to the nearest mV. The type of reference electrode in use and its filling solution should be recorded in at least one logbook as part of the field project records. exercised at very low flow rates where the media in the cup could potentially reexercised at very low flow rates where the media in the cup could potentially re parameter probesparameter probes guidelines for probe deployment described in guidelines for probe deployment described in Field Measurement of Dissolved Oxygen (Field Measurement of Dissolved Oxygen ( Operating Procedure for Operating Procedure for most recent version) apply. most recent version) apply. ORP probes ORP probes manufacturer’s instructions. manufacturer’s instructions. regular filling or replacement. Field Measurement of Dissolved Oxygen (LSASDPROC are commonly obtained with the use of an overtopping cell where the environmental are commonly obtained with the use of an overtopping cell where the environmental media is pumped into the bottom of a narrow cup (generally field fabricated fmedia is pumped into the bottom of a narrow cup (generally field fabricated f sample container) containing the instrument sensors. The sensors are continually sample container) containing the instrument sensors. The sensors are continually flushed with fresh media as the cup is allowed to overflow. Caution should be flushed with fresh media as the cup is allowed to overflow. Caution should be exercised at very low flow rates where the media in the cup could potentially reexercised at very low flow rates where the media in the cup could potentially re ORP measurements should be conducted in a fashion that prevents the addition ORP measurements should be conducted in a fashion that prevents the addition loss of any potential oxidants or reductants. Results could be compromised by loss of any potential oxidants or reductants. Results could be compromised by gas from gas from anoxic samanoxic sam dissolved oxygen measurements, ORP measurements should be conducted in situ or dissolved oxygen measurements, ORP measurements should be conducted in situ or (see the (see the LSASDLSASD LSASDPROCLSASDPROC are commonly obtained with the use of an overtopping cell where the environmental 3.3.5. ORP is a temperature sensitive measurement, but ORP instruments are not temperature compensated. Consequently, the media temperature should always be recorded at the same time as the ORP is recorded. Likewise, as ORP is often pH dependent, pH should also be recorded at the time of ORP measurement. 3.4. Reporting 3.4.1. In the absence of a specified reference scale, ORP data has no meaning. Therefore, the reference scale used should always be specified in reporting or discussing the ORP data. ORP measurements converted to a hydrogen scale can be reported as “Eh”. Data reported as the direct field measurement without correction might be described as “ORP referenced to Ag/AgCl electrode” or “EAg/AgCl”. The expectations of the data user should be ascertained, or the measurements should be reported in both systems. 3.4.2. To apply corrections to obtain Eh from the direct field measurement, the known half-cell potential of the reference electrode is added to the recorded field ORP value: , = + 3.4.3. The following table presents the half-cell potential of a silver/silver chloride reference electrode at various temperatures and with various molarities of KCl filling solutions. Table 1: Half-Cell Potential of Ag/AgCl Reference Molarity of KCl filling solution T(°C) 3M 3.3M* 3.5M Sat/4M 10 220 217 215 214 15 216 214 212 209 20 213 210 208 204 25 209 207 205 199 30 205 203 201 194 35 202 199 197 189 40 198 195 193 184 Derived from USGS NFM, Table 6.5.2 (9/2005) *interpolated value Note: YSI sondes and Thermo electrodes typically use 4M KCl filling solutions. Eureka sondes typically use 3.3M KCl filling solutions presents the halfpresents the half various temperatures and with various various temperatures and with various Table 1: Half: Half--: Half: Half: Half Cell Potential of Ag/AgCl RefereCell Potential of Ag/AgCl Refere T(°C)T(°C) might be described as “ORP referenced to Ag/AgCl electrode” or “might be described as “ORP referenced to Ag/AgCl electrode” or “ or the measurements should be or the measurements should be from the direct field measurement, from the direct field measurement, of the reference electrode is added to the recorded field ORP of the reference electrode is added to the recorded field ORP 3.4.3.1. Example: 3.4.3.1.1. A multi-parameter probe with a silver/silver chloride reference electrode and 4M KCl filling solution is used to record a stream ORP measurement of 146mV. The stream temperature is recorded as 15°C. 3.4.3.1.2. From the above table, the half-cell potential of an Ag/AgCl reference electrode filled with 4M KCl is 209mV at 15°C. Then: , = /, + / , = 146 + 209 , = 355 3.4.3.1.3. As noted in Section 3.3, Measurement, ORP measurements are sensitive to temperature, and may be sensitive to pH. As the instruments do not compensate for these parameters, ORP data should always be reported with the temperature and pH of the media at the time of measurement. 3.4.3.1.4. Final reporting values of Eh or ORP should be rounded to the nearest 10mV. The following spreadsheet formula can perform the rounding of an interim result located in spreadsheet cell ‘A1’: =(1 10 + 0.5)10 rounding of Final reportFinal reporting ing values values nearest 10mV. The following sprenearest 10mV. The following spre an interim result located in an interim result located in == MeasurementMeasurement maymay be sensitive to pH. As be sensitive to pH. As o not compensate for these parameterso not compensate for these parameters reported with the temperature reported with the temperature and pH and pH MeasurementMeasurement References Faulkner, S.P., W.H. Patrick, Jr., and R.P. Gambrell. 1989. Field techniques for measuring wetland soil parameters. Soil Sci. Soc. Am. J. 53:883-890. Megonigal, J.P., W.H. Patrick, Jr., and S.P. Faulkner. 1993. Wetland identification in seasonally flooded forest soils: soil morphology and redox dynamics. Soil Sci. Soc. Am. J. 57:140-149. D.K. Nordstrom and F.D. Wilde. 2005. National Field Manual, Chapter A6, Section 6.5: Reduction Oxidation Potential (Electrode Method). USGS. Pankow, J.E. 1991. Aquatic chemistry concepts. Lewis Publishers, Inc. Cheleas, Michigan. USA. Pruitt, B.A. 2001. Hydrologic and soil conditions across hydrogeomorphic settings. Dissertation. The University of Georgia, Athens, GA. USA. Soil Survey Staff. 1998. Keys to soil taxonomy, 8th Edition. United States Department of Agriculture, Natural Resources Conservation Service, Washington, DC. USA. Standard Methods. 1992. Standard Methods for the Examination of Water and Wastewater, 18th Edition. Prepared and published jointly by: American Public Health Association, American Water Works Association, Water Environment Federation. American Public Health Association, Washington, DC. USA. Stumm, W. and J.J. Morgan. 1981. Aquatic chemistry: an introduction emphasizing chemical equilibra in natural waters, 2nd Ed. John Wiley & Sons, New York. USA. EPA Region 4. 2019. Applied Science Branch Quality Project Plan. Region 4 Laboratory Services and Applied Science Division, Athens, GA. EPA Region 4. Region 4 Safety & Occupational Heal SharePoint Site. https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource s.aspx Wikipedia entry. Reduction Potential. http://en.wikipedia.org/wiki/Reduction_potential. Retrieved April 2, 2009. https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resourcehttps://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource Stumm, W. and J.J. Morgan. 1981. Aquatic chemistry: an introduction emphasizing chemical Stumm, W. and J.J. Morgan. 1981. Aquatic chemistry: an introduction emphasizing chemical equilibra in natural waters, 2nd Ed. John Wiley & Sonequilibra in natural waters, 2nd Ed. John Wiley & Son Applied Science Branch Applied Science Branch Services and Applied Science DivisionServices and Applied Science Division Region 4 Safety & Occupational Heal SharePoint Site. Region 4 Safety & Occupational Heal SharePoint Site. https://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resourcehttps://usepa.sharepoint.com/sites/R4_Community/Safety/SitePages/Forms%20and%20Resource Agriculture, Natural Resources Conservation Service, Washington, DC. USA. Standard Methods. 1992. Standard Methods for the Examination of Water and Wastewater, 18th Standard Methods. 1992. Standard Methods for the Examination of Water and Wastewater, 18th Edition. Prepared and published jointly by: American Public Health Association, American Edition. Prepared and published jointly by: American Public Health Association, American Water Works Association, Water Environment Federation. American Public Health Association, Water Works Association, Water Environment Federation. American Public Health Association, Pankow, J.E. 1991. Aquatic chemistry concepts. Lewis Publishers, Inc. Cheleas, Michigan. USA. Pankow, J.E. 1991. Aquatic chemistry concepts. Lewis Publishers, Inc. Cheleas, Michigan. USA. Pruitt, B.A. 2001. Hydrologic and soil conditions across hydrogeomorphic settings. Dissertation. Pruitt, B.A. 2001. Hydrologic and soil conditions across hydrogeomorphic settings. Dissertation. Soil Survey Staff. 1998. Keys to soil taxonomy, 8th Edition. United States Department oSoil Survey Staff. 1998. Keys to soil taxonomy, 8th Edition. United States Department o Agriculture, Natural Resources Conservation Service, Washington, DC. USA. Agriculture, Natural Resources Conservation Service, Washington, DC. USA. Revision History History Effective Date SESDPROC-113-R3, Field Measurement of Oxidation-Reduction Potential, replaces SESDPROC-013-R2 SOP was put in the new SOP format. Replace SESD with LSASD and updated SOP reference numbers throughout the document. Updated the reference section. December 17, 2021 SESDPROC-113-R2, Field Measurement of Oxidation-Reduction Potential (ORP), replaces SESDPROC-013-R1 General: Corrected any typographical, grammatical, and/or editorial errors. Title Page: Changed the EIB Chief from Danny France to the Field Services Branch Chief John Deatrick, and the Field Quality Manager from Bobby Lewis to Hunter Johnson. Section 2.2: Figure 6 modified for clarity. Section 3.3: Use of overtopping cell described consistent with current practice. April 26, 2017 SESDPROC-113-R1, Field Measurement of Oxidation-Reduction Potential (ORP), replaces SESDPROC-013-R0 January 29, 2013 SESDPROC-113-R0, Field Measurement of Oxidation-Reduction Potential (ORP), Original Issue August 7, 2009 R1, R1, Field Measurement of OxidationField Measurement of Oxidation , replaces SESDPROC, replaces SESDPROC Changed the EIB Chief from Danny France to the Field Changed the EIB Chief from Danny France to the Field Branch Chief John Deatrick, and the Field Quality Manager from Bobby Branch Chief John Deatrick, and the Field Quality Manager from Bobby : Figure 6 modified for clarity.: Figure 6 modified for clarity. : Use of overtopping cell described consistent with current : Use of overtopping cell described consistent with current Reduction Potential Reduction Potential Corrected any typographical, grammatical, and/or editorial errors. Corrected any typographical, grammatical, and/or editorial errors. Changed the EIB Chief from Danny France to the Field Changed the EIB Chief from Danny France to the Field December 17, 2021December 17, 2021 Reduction Potential Reduction Potential LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 1 of 9 Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field pH Measurement ID: LSASDPROC-100-R5 Issuing Authority: LSASD Field Branch Chief Review Issue Date: July 23, 2020 Review Due Date: July 23, 2024 Purpose This document describes procedures, methods and considerations to be used and observed when conducting field pH measurements in aqueous phase environmental media, including groundwater, surface water and certain wastewaters. Scope/Application The procedures contained in this document are to be used by field personnel when measuring the pH of aqueous phase environmental media in the field. On the occasion that LSASD field personnel determine that any of the procedures described in this section cannot be used to obtain pH measurements of the media being sampled, and that another method must be used to obtain said measurements, the variant instrument and/or measurement procedure will be documented in the field logbook and subsequent investigation report, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 2 of 9 TABLE OF CONTENTS Purpose .............................................................................................................................. 1 Scope/Application............................................................................................................. 1 1 General Information ................................................................................................. 3 1.1 Documentation/Verification ..................................................................................... 3 1.2 General Precautions ................................................................................................. 3 1.2.1 Safety ............................................................................................................... 3 1.2.2 Procedural Precautions.................................................................................. 3 2 Quality Control ......................................................................................................... 3 3 Field pH Measurement Procedures......................................................................... 4 3.1 General....................................................................................................................... 4 3.2 Instrument Calibration............................................................................................ 4 3.3 Field Measurement Procedures............................................................................... 6 3.3.1 Grab Sample Measurements ......................................................................... 6 3.3.2 Overtopping Cell Measurements .................................................................. 6 3.3.3 In-Situ Measurements.................................................................................... 7 3.3.4 Sample Preservation Verification ................................................................. 7 3.4 Operational Check.................................................................................................... 7 References.......................................................................................................................... 8 Revision History ................................................................................................................ 9 LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 3 of 9 1 General Information 1.1 Documentation/Verification This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on LSASD’s local area network (LAN). The Document Control Coordinator is responsible for ensuring that the most recent version of the procedure is placed on LSASD’s LAN and for maintaining records of review conducted prior to its issuance. 1.2 General Precautions 1.2.1 Safety Proper safety precautions must be observed when conducting field pH measurements. Refer to the LSASD Safety, Health and Environmental Management Program Procedures and Policy Manual (Most Recent Version) and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 1.2.2 Procedural Precautions All field pH measurements pertinent to the sampling event should be recorded in the field logbook for the event. All records, including a unique, traceable identifier for the instrument, such as a property number or serial number, should be entered according to the procedures outlined in the LSASD Operating Procedure for Logbooks (LSASDPROC-010) and the LSASD Operating Procedure for Equipment Inventory and Management, (LSASDPROC-108). Care should be taken not to contaminate standards and samples and verify the expiration date of all standards prior to use. All meters should be calibrated, operated and maintained according to the manufacturer’s specifications. 2 Quality Control All pH meters will be maintained and operated in accordance with the manufacturer's instructions and the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-108). Before a meter is taken to the field, it will be properly calibrated or verified, according to Section 3.2 of this procedure, to ensure it is operating properly. These calibration and verification checks will be documented and maintained in a logbook. Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 4 of 9 The ambient temperature in the immediate vicinity of the meter should be measured and recorded in the field logbook to ensure the instrument is operated within the manufacturer’s specified range of operating temperatures, although this is typically not necessary for ecological studies. For instruments that are deployed for in-situ measurements, the temperature of the medium being monitored should be measured and recorded in the logbook prior to deployment. In-situ monitoring equipment may be utilized in unattended deployments where autonomous logging may preclude temperature measurement prior to deployment. Because in-situ instrumentation generally has a wide range of operating temperatures, the field investigator may utilize professional judgment in determining if the operating environment is suitable for unattended deployment. If at any time during a field investigation, it appears that the environmental conditions could jeopardize the quality of the measurement results, the measurements will be stopped. This will be documented in the field logbook. 3 Field pH Measurement Procedures 3.1 General pH is defined as the negative logarithm of the effective hydrogen-ion concentration. The ion selective pH electrode measures the difference in potentials between the two sides in a glass electrode. The circuit is closed through internal solutions of the electrode and the external solution that is being measured and the pH meter. As the electrode is immersed in the test solution the glass bulb senses the positive charged hydrogen ions as millivolts (mV). The pH meter measures the difference between an internal electrode and a reference electrode. This mV reading is then read by the meter and is displayed in pH units. For routine work, a pH meter accurate and reproducible to within 0.2 Standard Units (S.U.) is suitable. For NPDES compliance monitoring, the pH meter should be accurate and reproducible to within 0.1 S.U. Both meters should have a range of 0 to 14 S.U. and be equipped with a temperature-compensation adjustment. Modern pH meters usually have a protective housing around the glass bulb but are sensitive scientific instruments and should be handled with care. Most pH electrodes last from one to two years, depending on the deployment environment and if proper storage solution was used during periods of inactivity. 3.2 Instrument Calibration Many brands of instruments are commercially available for the measurement of pH incorporating a wide variety of technologies. The manufacturer’s instruction manual should be consulted for specific procedures regarding their calibration, maintenance and use. Calibration of any measurement instrument must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate. At a minimum, a two-point calibration should be conducted to ensure the accuracy of the meter. The following are basic guidelines for calibration/verification and are provided as an example (procedure may vary based on the instrument used): Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 5 of 9 1.Verify the meter’s internal temperature sensor (thermistor) against a National Institute of Standards and Technology (NIST) traceable thermometer and note any differences between the thermistor and the NIST-traceable thermometer in the logbook. If the temperatures do not agree within ± 4 C, the unit or probe must be repaired or replaced. Alternatively, if the meter can be used in a manual temperature compensation mode, the NIST-traceable thermometer may be used for temperature readings and the necessary corrections applied. Check and record the temperatures of the standards and the samples. 2.If the pH range of the sample is not known, the pH of the sample to be tested should be estimated either from historical data or by using a four-color pH indicator paper or equivalent. Using this information, calibrate the pH meter with the buffers that bracket the expected pH range. Buffer solutions are commonly pH 4, 7 and 10. It may be possible to configure the pH meter so that it can be standardized with buffers other than those in the default configuration. Note that buffer values are temperature specific (reading true at 25°C) and be sure to input the correct buffer calibration value for the given temperature in step 3 below. Some pH probes are capable of Automatic Temperature Compensation (ATC) and will recognize the correct temperate corrected value of the calibration standard. 3.Immerse the probe in the required buffer solutions and record pre-cal values (pH 7 buffer is typically the first cal point). Then re-immerse the probe to calibrate to the correct pH buffer value, also recording the post-cal value. Rinse the probe with de-ionized water and blot dry or otherwise remove excess rinse water between the different buffer solutions. Record the buffer values and temperatures used to calibrate the meter. 4. Rinse the probe with de-ionized water, blot dry or otherwise remove excess rinse water and immerse it into the appropriate buffer and read as a measurement. If the meter reads within ± 0.2 S.U. of the known value of the buffer (for general applications such as ecological studies) or ± 0.1 S.U. (for regulatory applications such as NPDES or drinking water programs), record the value indicated by the meter. If the meter is outside of the acceptable accuracy range, it should be recalibrated. If it is still outside of the acceptable accuracy range after the second calibration, the electrode and/or meter should be replaced. 5.Once the meter has been properly calibrated and verified (steps 1-4 above), it is ready for use. Rinse the probe with de-ionized water and store it according to manufacturer’s recommendations. Certain instruments may require being left on until all measurements are performed and the results are recorded. When collecting measurements from grab samples, certain instrument manufacturers recommend that an intermediate check(s) be performed by periodically checking the meter against a known calibration buffers if used for extended periods (> 4 hrs). 6.Unless the manufacturer indicates that the meter maintains its calibration after being turned off, meters must be re-calibrated if they are turned off during their period of use. Note: If multi-parameter sondes are used, calibrate according to the manufacturer’s specifications and procedural directions. Calibration procedures for sondes for in-situ monitoring may in some cases be different than those for field pH meters using open probes. Those procedures are documented in LSASD’s SOP listed as: LSASDPROC-111-R4, In-Situ Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 6 of 9 Water Quality Monitoring 3.3 Field Measurement Procedures Measurements in the field may occur under several conditions, requiring various specific procedures. A pH probe should never be placed in an analytical sample to avoid cross-contamination, only sample aliquots should be used as a surrogate for sample pH measurements. Use of the word sample below implies that a sample aliquot has been collected. 3.3.1 Grab Sample Measurements These procedures should be followed when conducting field pH measurements of grab sample: 1. Collect a sample. If the meter’s thermistor is to be used for the temperature of record for the measurement activity, the temperature should be read as soon as the reading stabilizes and prior to measuring the pH. Note 1a: When the pH meter response is slow, unstable, or non-reproducible, it may be necessary to check the conductivity. If the conductivity is lower than 20 to 30 µmhos/cm, it is permissible to add 1 ml of 1M potassium chloride solution per 100 ml of sample to improve response time for the probe. Recheck the pH and record. Note 1b: If the pH measurements are to be used for RCRA regulatory purposes and when the e scale, the pH measurements should be made by a qualified analyst using laboratory quality equipment to control the sample at 25 C ± 1oC. 2.Immerse the lower part of the probe in the sample. Typically, in the field, the pH probe is not kept away from container bottom or sides during calibration, or during field readings in an overtopping cell, as it is not practical. End of day readings are also performed the same way. Allow ample time for the probe to equilibrate with the sample. 3. While suspending the probe in the sample container, record the pH. 4. Rinse the probe with de-ionized water and replace end cap if applicable. For longer term storage, place probe in the manufacturer’s recommended storage solution. 3.3.2 Overtopping Cell Measurements Often during groundwater sampling, an overtopping cell may be used with purge water constantly flowing through the cell during purging. These procedures should be followed when conducting field pH measurements using an overtopping cell: 1. Immerse the bottom portion of the probe in the open-top container being used for purge water Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 7 of 9 flow-through. Allow it to equilibrate with the purge water and stabilize until the meter indicates that it is ready for readings. Readings may be recorded at certain timed intervals in the field, prior to collecting the sample for laboratory analysis. 2.When finished at one sampling station during the day and moving to the next, the protective end cap should be placed on the probe until ready for use again. 3.3.3 In-Situ Measurements These procedures should be followed when conducting in-situ field pH measurements: 1. Place the probe/sonde into the media to be measured and allow the pH and temperature readings to stabilize. Once the readings have stabilized, record the measurements in the logbook. 2. When deploying meters for extended periods of time, ensure the measurement location is representative of average media conditions. Note: If multi-parameter sondes are used for pH measurement, procedures such as for depth profiling of pH, may be different than for pH meters with open probes. Those procedures are documented in LSASD’s SOP listed as: LSASDPROC-111-R4, In-Situ Water Quality Monitoring. 3.3.4 Sample Preservation Verification When verifying the pH for sample preservation in a field sample collected for laboratory analysis, this procedure should be followed: 1. Pour a small amount of sample from bottle over a pH strip to determine if the sample has been preserved to the specified pH range; meters are not needed. Be sure to properly dispose of used pH strips, as contaminant level is likely unknown. 3.4 Operational Check Even though it is not necessary to re-calibrate pH meters at regular intervals during the day, depending on the instrument, it may be appropriate to occasionally perform operational checks to determine if site conditions, such as an increase in temperature, have impacted the meter’s performance. If an operational check is warranted, the following procedure should be followed to ensure that the performance of the meter has not changed. 1. While in use, periodically check the pH by rinsing the probe with de-ionized water, blot dry or Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 8 of 9 otherwise remove excess rinse water and immerse it into the appropriate buffer solution. If the measured pH differs by 0.2 S.U. or 0.1 S.U. (depending on the application) from the buffer solution, the meter must be re-calibrated. A post-operation instrument verification check will be performed using the appropriate buffer(s) at the end of the day or after all measurements have been taken for a particular period of operation. These measurements must be recorded in the field logbook. References LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-108, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version United States Environmental Protection Agency (US EPA). 2001. Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Science and Ecosystem Support Division (LSASD Athens, GA USEPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version. Uncontrolled When Printed LSASDPROC-100-R5 Field pH Measurement Effective Date: July 23, 2020 _______________________________________________________________________________________________________ Page 9 of 9 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Document Control Coordinator on the LSASD local area network (LAN). History Effective Date LSASDPROC-100-R5, Field pH Measurement,replaces SESDPROC-100-R4 General: Corrected any typographical, grammatical, and/or editorial errors. Updated document format and naming convention. Replaced SESD and FSB with LSASD and ASB throughout due to Agency Re-alignment. Added language to Section 3.2 to specify that pH readings are temperature dependent and include steps for entering the current temperature when calibrating meters. Included language for documenting pre cal and post calibration readings. Section 3.3- clarified that pH meters should not be placed in samples to prevent contamination. Added Section 3.3.2 for performing pH measurement using overtopping cells. Added language for long term storage of probes to Section 3.3.1.3 Updated References July 23, 2020 LSASDPROC-100-R4, Field pH Measurement,replaces LSASDPROC-100-R3 General: Corrected any typographical, grammatical, and/or editorial errors. Title Page: Changed the Field Quality Manager from Bobby Lewis to Hunter Johnson. Updated cover page to represent LSASD reorganization. John Deatrick was not listed as the Chief of the Field Services Branch December 16, 2016 LSASDPROC-100-R3, Field pH Measurement,replaces LSASDPROC-100-R2 January 29, 2013 LSASDPROC-100-R2, Field pH Measurement,replaces LSASDPROC-100-R1 June 13, 2008 LSASD-100-R1, Field pH Measurement, replaces LSASDPROC-100-R0 November 1, 2007 LSASDPROC-100-R0, Field pH Measurement, Original Issue February 05, 2007 Uncontrolled When Printed LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 1 of 8 Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia OPERATING PROCEDURE Title: Field Specific Conductance Measurement ID: LSASDPROC-101-R7 Issuing Authority: LSASD Field Branch Chief Effective Date: May 5, 2020 Review Date: May 5, 2023 Purpose This document describes procedures, methods and considerations to be used and observed when conducting field specific conductance measurements in aqueous phase environmental media, including groundwater, surface water and certain wastewaters. Scope/Application The procedures contained in this document are to be used by field investigators when measuring the specific conductance of aqueous phase environmental media in the field. On the occasion that LSASD field investigators determine that any of the procedures described in this section cannot be used to obtain specific conductance measurements of the media being sampled, and that another method must be used to obtain said measurements, the variant instrument and/or measurement procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 2 of 8 TABLE OF CONTENTS Purpose .................................................................................................................................................... 1 Scope/Application ................................................................................................................................... 1 1 General Information ......................................................................................................................3 1.1 Documentation/Verification ......................................................................................................... 3 1.2 General Precautions...................................................................................................................... 3 1.2.1 Safety ........................................................................................................................................... 3 1.2.2 Procedural Precautions................................................................................................................. 3 2 Quality Control ..............................................................................................................................3 3 Field Specific Conductance Measurement Procedures .................................................................4 3.1 General ......................................................................................................................................... 4 3.2 Instrument Calibration and Verification ...................................................................................... 4 3.3 Sample Measurement Procedures ................................................................................................ 5 3.4 Operational Checks ...................................................................................................................... 6 References ............................................................................................................................................... 7 LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 3 of 8 1 General Information 1.1 Documentation/Verification This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD local area network (LAN). The Document Control Coordinator is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance. 1.2 General Precautions 1.2.1 Safety Proper safety precautions must be observed when conducting field specific conductance measurements. Refer to the LSASD Safety, Health and Environmental Management Program Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 1.2.2 Procedural Precautions All field specific conductance measurements pertinent to the sampling event, including a unique, traceable identifier for the instrument, such as a property number or serial number, should be recorded in the field logbook for the event. All records should be entered according to the procedures outlined in the LSASD Operating Procedure for Logbooks (LSASDPROC-010, most recent version). Care should be taken to not contaminate standards and samples and verify the expiration date of all standards prior to use. All meters should be calibrated, operated and maintained according to the manufacturer’s specifications. 2 Quality Control All specific conductance meters will be maintained and operated in accordance with the manufacturer's instructions and the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-108, most recent version). Before a meter is taken to the field, it will be properly calibrated or verified, according to Section 3.2 of this procedure, to ensure it is operating properly. These calibration and verification checks will be documented and maintained in a logbook. The ambient temperature in the immediate vicinity of the meter should be measured and recorded in the field logbook to ensure the instrument is operated within the manufacturer’s specified range of operating temperatures. For instruments that are deployed for in-situ measurements, the temperature of the medium being monitored should be measured and recorded in the logbook prior to deployment. In-situ monitoring equipment may be utilized in unattended deployments where autonomous logging may preclude LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 4 of 8 temperature measurement prior to deployment. Because in-situ instrumentation generally has a wide range of operating temperatures, the field investigator may utilize professional judgment in determining if the operating environment is suitable for unattended deployment. If at any time during a field investigation it appears that the environmental conditions could jeopardize the quality of the measurement results, the measurements will be stopped. This will be documented in the field logbook. 3 Field Specific Conductance Measurement Procedures 3.1 General Specific conductance is a measure of the ability of an aqueous solution to conduct an electric current and is customarily reported in microsiemens per centimeter (µS/cm) or micromhos per centimeter (µmhos/cm) at 25°C. It is important to note that if the specific conductance measurements are for NPDES reporting purposes, the meter and conductivity cell should be verified by comparing against a laboratory meter with a platinum-electrode type conductivity cell. 3.2 Instrument Calibration and Verification Many brands of instruments are commercially available for the measurement of specific conductance incorporating a wide variety of technologies. The manufacturer’s instruction manual should be consulted for specific procedures regarding their calibration, maintenance and use. Calibration of any measurement instrument must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate. Conductivity is affected by temperature; therefore, for instruments that do not automatically compensate for temperature, the user should document temperature first so that appropriate adjustments can be made in accordance with the manufacturer’s instructions and/or method. The following are basic guidelines for calibration/verification and are provided as an example: 1. Verify the meter’s internal temperature sensor (thermistor) against a National Institute of Standards and Technology (NIST) traceable thermometer and note any differences between the thermistor and the NIST-traceable thermometer in the logbook. If the temperatures do not agree within ± 4°C, the unit must be repaired or replaced. Alternatively, if the meter can be used in a manual temperature compensation mode, the NIST-traceable thermometer may be used for temperature readings and the necessary corrections applied. Check and record the temperatures of the standards and the samples. 2. Rinse the probe with de-ionized water and blot dry before conducting the following calibration and verification checks. 3. Immerse the probe in the first standard solution and calibrate or verify the meter against that solution. Fresh standards should be used for each calibration. After the initial standard, calibrate and/or verify the meter using additional standards, as appropriate. Rinse the probe with de-ionized water and blot dry or otherwise remove excess rinse water between the LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 5 of 8 different standards. Record the standard values/temperatures used to calibrate or verify the meter. Note: Some instruments require that calibration standards reflect the anticipated specific conductance of the media being measured. 4. Some meters will auto-recognize standards during calibration. For example, the Thermo Star Series meter will auto-recognize standards 1413 µS/cm, 100 µS/cm and 12.9 mS/cm. If the meter is calibrated in a manner where it does not auto-recognize the standard, and the meter is not accurate to ± 10 % of the standard solution(s) known values, the meter or probe should be repaired or replaced. If this condition can be corrected by adjusting the cell constant of the probe, refer to the instruction manual and make the adjustment. Note: The Thermo Star A325 units primarily used for ground water investigations should be set to Temperature Correction mode nLFn for best results. 5. After calibration is complete, place the probe back into the calibration standard used and record a post-calibration reading. Record a post calibration reading for each standard used. If the meter is not accurate to within ± 10 % of the standard solution(s) known values, it should be recalibrated. If it is still outside of the acceptable accuracy range after the second calibration, the probe and/or meter should be replaced. 6. Once the meter has been properly calibrated and verified (steps 1-5 above), it is ready for use. Rinse the probe with de-ionized water and store it in the manufacturer’s recommended storage solution. Certain meters may require that the instrument be left on until all sample measurements are performed and the results are recorded. When collecting measurements from grab samples, certain instrument manufacturers recommend that an intermediate check(s) be performed by periodically checking the meter against the known calibration standards if used for extended periods (> 4 hrs). 3.3 Sample Measurement Procedures The following procedures should be followed when conducting field specific conductance measurements of grab samples: 1. Collect the sample, check and record its temperature. 2. Correct the instrument’s temperature adjustment to the temperature of the sample (if required). 3. Immerse the probe in the sample keeping it away from the sides and bottom of the container. It is important that the center portion of the probe be wetted by the sample. 4. Allow meter to stabilize. Record the results in a logbook. 5. Rinse probe with de-ionized water. LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 6 of 8 The following procedures should be followed when conducting in-situ field specific conductivity measurements: 1. Place the probe into the media to be measured and allow the specific conductivity and temperature readings to stabilize. Once the readings have stabilized, record the measurements in the logbook. 2. When deploying meters for extended periods of time, ensure the measurement location is representative of average media conditions. 3.4 Operational Checks Even though it is not necessary to re-calibrate conductivity meters at regular intervals during the day, depending on the instrument, it may be appropriate to occasionally perform operational checks to determine if site conditions, such as an extreme temperature change, have impacted the meter’s performance. If an operational check is warranted, the following procedures should be followed to ensure that the performance of the meter has not changed. Check the conductivity meter with fresh conductivity standard. Rinse the conductivity probe with deionized water, blot dry or otherwise remove excess rinse water and immerse it into the appropriate conductivity standard. If the measured conductivity value is not with ± 10% of the standard, the probe should be re-calibrated. If the probe is still not within ± 10% of the standard, the probe should be repaired or replaced. These measurements must be recorded in the field logbook. A post-operation instrument verification check should be performed using the appropriate standard(s) at the end of the day or after all measurements have been taken for a particular period of operation. These measurements must be recorded in the field logbook. LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 7 of 8 References LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-108, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version United States Environmental Protection Agency (US EPA). 2001. Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Laboratory Services & Applied Science Division (LSASD), Athens, GA US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version LSASDPROC-101-R7 Field Specific Conductance Effective Date: May 5, 2020 Page 8 of 8 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Document Control Coordinator on the LSASD local area network (LAN). History Effective Date LSASDPROC-101-R7 Field Specific Conductance Measurement, replaces SESDPROC-101-R6 General: Corrected any typographical, grammatical, and/or editorial errors. Changed references to Division Name to match current organization Cover Page: Changed Names of Division and approving officials to reflect current organization. Section 3.2 added a reference to the appropriate temperature compensation setting for the Thermo Star A325. May5, 2020 SESDPROC-101-R6, Field Specific Conductance Measurement, replaces SESDPROC-101-R5 General: Corrected any typographical, grammatical, and/or editorial errors. Throughout the document mention of quality system or SESD quality system was replaced with Field Branches Quality System or FBQS. Cover Page: Omitted Hunter Johnson as an author. Updated cover page to represent SESD reorganization. John Deatrick was not listed as the Chief of the Field Services Branch. July 13, 2016 SESDPROC-101-R5, Field Specific Conductance Measurement, replaces SESDPROC-101-R4 August 30, 2012 SESDPROC-101-R4, Field Specific Conductance Measurement, replaces SESDPROC-101-R3 January 13, 2012 SESDPROC-101-R3, Field Specific Conductance Measurement, replaces SESDPROC-101-R2 August 12, 2011 SESDPROC-101-R2, Field Specific Conductance Measurement, replaces SESDPROC-101-R1 June 13, 2008 SESDPROC-101-R1, Field Specific Conductance Measurement, replaces SESDPROC-101-R0 November 1, 2007 SESDPROC-101-R0, Field Specific Conductance Measurement, Original Issue February 05, 2007 Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field Temperature Measurement ID: LSASDPROC-102-R6 Issuing Authority: FSB Branch Chief Effective Date: April 8, 2022 Next Review Date: April 8, 2026 Method Reference: NA Author: Mel Parsons Purpose This document describes general and specific procedures, methods and considerations to be used and observed when measuring the temperature of aqueous phase environmental media, including groundwater, surface water and certain wastewaters. Scope/Application The procedures contained in this document are to be used by field personnel when measuring the temperature of aqueous phase environmental media in the field. On the occasion that LSASD field personnel determine that any of the procedures described in this section cannot be used to obtain temperature measurements of the media being sampled, and that another method or measurement instrument must be used to obtain said measurements, the variant instrument and measurement procedure will be documented in the field logbook and subsequent investigation report, along with a description of the circumstances requiring its use. While this SOP may be informative, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Note: LSASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, signatures, SOPs, and forms as they are developed, which will also be housed on the Local Area Network (LAN) and traceable to each project. Field Temperature Measurement Effective Date: April 8, 2022 Approved by FSB Chief Page 2 of 6 LSASDPROC-102-R6 040822 Table of Contents 1. Field Temperature Measurement Procedures _____________________________________________ 3 1.1 General ______________________________________________________________________ 3 1.2 Instrument Verification __________________________________________________________ 3 1.3 Inspections ___________________________________________________________________ 4 1.4 Sample measurement procedures for thermometers/thermistors __________________________ 4 1.5 Units ________________________________________________________________________ 4 1.6 Quality Control ________________________________________________________________ 4 1.7 Definitions____________________________________________________________________ 4 References __________________________________________________________________________ 5 Revision History _____________________________________________________________________ 6 Field Temperature Measurement Effective Date: April 8, 2022 Approved by FSB Chief Page 3 of 6 LSASDPROC-102-R6 040822 1. Field Temperature Measurement Procedures 1.1 General Field temperature measurements may be made with a field thermometer, equipment thermistor, or National Institute of Standards and Testing (NIST)-traceable thermometer. At a minimum, the temperature measurement device should be capable of measuring in 0.1°C increments. 1.2 Instrument Verification 1.2.1 Field thermometers and thermistors Temperature measurement devices such as field thermometers and equipment thermistors will be verified against a NIST-traceable thermometer prior to use and should agree within ± 4.0°C. Corrections may be applied for measurements up to ± 4.0°C depending on investigation objectives, but the instrument must be repaired or replaced beyond that range. Due to the stable nature of thermistors on multi-parameter water quality instruments, thermistors will be checked at the beginning and end of a field study, but do not have to be checked for every calibration during the study. In order to track stability and reliability, the thermistors on these units will be checked against a NIST-traceable thermometer on an annual basis, with the electronic record of these checks maintained on the Water Quality Section Sharepoint Site. In order to provide the most stable readings, thermistor checks against the NIST- traceable thermometer should be conducted in a liquid calibration standard at stabilized room temperature as opposed to air during the saturated air calibration of dissolved oxygen. Enforcement cases would still require temperature verification for every calibration and end check related to the case. 1.2.2 NIST-traceable thermometer Verification of the NIST-traceable thermometers that are used to verify temperature measuring devices is accomplished by comparing temperature readings from the NIST-traceable thermometer to a thermometer that has an independent certification of accuracy traceable to the National Institute of Standards and Testing. Currently certified thermometers, or reference thermometers, are maintained by the LSASD Laboratory Support Branch. Each NIST-traceable thermometer is verified by comparing at least annually against a reference thermometer. If corrections need to be applied, they will be noted in the NIST-traceable thermometer log. Depending on investigation objectives, project leaders may decide to apply the correction factor as necessary. Field Temperature Measurement Effective Date: April 8, 2022 Approved by FSB Chief Page 4 of 6 LSASDPROC-102-R6 040822 1.3 Inspections All temperature measurement devices should be inspected for leaks, cracks, and/or function prior to each use. 1.4 Sample measurement procedures for thermometers/thermistors (Make measurements in-situ when possible) 1. Clean the probe end with de-ionized water and immerse into sample. 2. If not measuring in-situ, swirl the instrument in the sample for mixing and equilibration. 3. Allow the instrument to equilibrate with the sample for at least one minute. 4. Suspend the instrument away from the sides and bottom, if not in-situ, to observe the temperature reading. 5. Record the reading in the log book. For most applications, report temperature readings to the nearest 0.5 °C or to the nearest 0.1 °C depending on need. Note: Always clean the thermometer with de-ionized water or a detergent solution, if appropriate, prior to storage and/or use. 1.5 Units Degrees Celsius (°C) or Degrees Fahrenheit (°F) Conversion Formulas: °F = (9/5 °C) + 32 or °C = 5/9 (°F - 32) 1.6 Quality Control All thermometers should be maintained and operated in accordance with the manufacturer's instructions and the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-1009). Temperature measurement devices such as pH, conductivity and dissolved oxygen (DO) meter thermistors will be verified against a NIST-traceable thermometer before each use as described in Section 3.2. If at any time during a field investigation, it appears that the environmental conditions could jeopardize the quality of the measurement results, the measurements will be stopped. This will be documented in the field logbook. 1.7 Definitions None Field Temperature Measurement Effective Date: April 8, 2022 Approved by FSB Chief Page 5 of 6 LSASDPROC-102-R6 040822 References LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-1009, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version United States Environmental Protection Agency (US EPA). Most Recent Version. Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Science and Ecosystem Support Division (LSASD), Athens, GA US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version Field Temperature Measurement Effective Date: April 8, 2022 Approved by FSB Chief Page 6 of 6 LSASDPROC-102-R6 040822 Revision History History Effective Date LSASDPROC-102-R6, Field Temperature Measurement, replaces SESDPROC-102-R5 General: Corrected any typographical, grammatical, and/or editorial errors. Additionally, the document was edited to reflect the new Division name. March 14, 2022 SESDPROC-102-R5, Field Temperature Measurement, replaces SESDPROC-102-R4 General: Corrected any typographical, grammatical, and/or editorial errors. Additionally, the document was edited to reflect new Document Control Processes. Section 1.2.1: Verification requirements of thermistors on multi-parameter water quality instruments were modified. March 14, 2018 SESDPROC-102-R4, Field Temperature Measurement, replaces SESDPROC-102-R3 October 23, 2014 SESDPROC-102-R3, Field Temperature Measurement, replaces SESDPROC-102-R2 February 4, 2011 SESDPROC-102-R2, Field Temperature Measurement, Replaces SESDPROC-102-R1 June 13, 2008 SESDPROC-102-R1, Field Temperature Measurement, Replaces SESDPROC-102-R0 November 1, 2007 SESDPROC-102-R0, Field Temperature Measurement, Original Issue February 05, 2007 Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field Turbidity Measurement ID: LSASDPROC-103-R5 Issuing Authority: Chief, Field Services Branch Effective Date: November 3, 2021 Next Review Date: November 3, 2025 Method Reference: NA Author: Michael Roberts Purpose This document describes general and specific procedures, methods and considerations to be used and observed when conducting field turbidity measurements in aqueous phase environmental media, including groundwater, surface water and certain wastewaters. This Standard Operating Procedure (SOP) is specific to the Field Services Branch (FSB) to maintain conformance to technical and quality system requirements. While this SOP may be informative for other businesses, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Scope/Application The procedures contained in this document are to be used by field personnel when measuring turbidity of various, aqueous phase environmental media in the field. On the occasion that LSASD field personnel determine that any of the procedures described in this section cannot be used to obtain turbidity measurements of the media being sampled, and that another method or turbidity measurement instrument must be used to obtain said measurements, the variant instrument and measurement procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Note: LSASD is currently migrating to a paperless organization. As a result, this SOP will allow for the use of electronic logbooks, checklists, signatures, SOPs, and forms as they are developed, which will also be housed on the Local Area Network (LAN) and traceable to each project. Michael Roberts his document describes general and specific procedures, methods and considerations to be used his document describes general and specific procedures, methods and considerations to be used and observed when conducting field turbidity measurements in aqueous phase environmental and observed when conducting field turbidity measurements in aqueous phase environmental media, including groundwater, surface water and certain wastewaters. This Standard Operating media, including groundwater, surface water and certain wastewaters. This Standard Operating Procedure (SOP) is specific to the Field Services Branch (FSB) to maintain conformance to Procedure (SOP) is specific to the Field Services Branch (FSB) to maintain conformance to technical and quality system requirements. While this SOP may be informative for other technical and quality system requirements. While this SOP may be informative for other businesses, it is not intended for and may not be directly applicable to operations in other businesses, it is not intended for and may not be directly applicable to operations in other organizations. Mention of trade names or commercial products in this operating procedure does organizations. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. not constitute endorsement or recommendation for use. he procedures contained in this document are to be used by field personnel when measuring he procedures contained in this document are to be used by field personnel when measuring turbidity of various, aqueous phase environmental media in the field. On the occasion that turbidity of various, aqueous phase environmental media in the field. On the occasion that LSASD field personnel determine that any of the procedures described in this section cannot be LSASD field personnel determine that any of the procedures described in this section cannot be used to obtain turbidity measurements of the media being sampled, and that another method or used to obtain turbidity measurements of the media being sampled, and that another method or turbidity measurement instrument must be used to obtain said measurements, the variant turbidity measurement instrument must be used to obtain said measurements, the variant instrument and measurement procedure will be documented in the field logbook, along with a Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 2 of 12 LSASDPROC-103-R5 110321 Table of Contents 1. General Information _______________________________________________________ 3 2. Quality Control ___________________________________________________________ 3 3. Field Turbidity Measurement Procedures _______________________________________ 4 Table 1: Reporting Requirements (APHA, 1992) _____________________________________ 7 References___________________________________________________________________ 9 Revision History _____________________________________________________________ 10 Figure 1: Turbidity Method Decision Tree, adapted from Figure 6.7-2 (USGS 2005) _______ 11 Table 2: Turbidity Technology, Units, Application, & Design (adapted from ASTM International 2012) ______________________________________________________________________ 12 Revision History _____________________________________________________________ 10Revision History _____________________________________________________________ 10 Figure 1: Turbidity Method Decision Tree, adapted from Figure 6.7-2 (USGS 2005) _______ 11Figure 1: Turbidity Method Decision Tree, adapted from Figure 6.7-2 (USGS 2005) _______ 11 Table 2: Turbidity Technology, Units, Application, & Design (adapted from ASTM International Table 2: Turbidity Technology, Units, Application, & Design (adapted from ASTM International 2012) ______________________________________________________________________ 122012) ______________________________________________________________________ 12 Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 3 of 12 LSASDPROC-103-R5 110321 Procedural Section 1. General Information 1.1. Documentation/Verification 1.1.1. This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and has been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD local area network (LAN). The Document Control Coordinator is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance. 1.2. General Precautions 1.2.1. Safety 1.2.1.1 Proper safety precautions must be observed when conducting field turbidity measurements. Refer to the LSASD Safety, Health and Environmental Management Program (SHEMP) Manual (Most Recent Version) and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. When using this procedure, minimize exposure to potential health hazards through the use of protective clothing, eye wear and gloves. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 1.2.2. Procedural Precautions 1.2.2.1 All field turbidity measurements pertinent to the sampling event should be recorded in the field logbook for the event. All records should be entered according to the procedures outlined in the LSASD Operating Procedure for Logbooks (LSASDPROC-010). 2. Quality Control 2.1. All turbidity meters and probes shall be maintained and operated in accordance with the manufacturer's instructions and the LSASD Operating Procedure for Equipment Inventory and Management (LSASDPROC-108). Before a meter or probe is taken to the field, it shall be properly calibrated or verified, according to Sections 3.2 of this procedure, to ensure it is operating properly. These calibration and verification checks shall be documented and maintained in a logbook. and for maintaining records of review conducted and for maintaining records of review conducted Proper safety precautions must be observed when conducting field Proper safety precautions must be observed when conducting field Refer to the Refer to the LSASDLSASD Environmental Management Program Environmental Management Program and any pertinent site-and any pertinent site-specific Health for guidelines on safety precautions. These guidelines, however, should for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. only be used to complement the judgment of an experienced professional. When using this procedure, minimize exposure to potential health hazards When using this procedure, minimize exposure to potential health hazards through the use of protective clothing, eye wear and gloves. Address through the use of protective clothing, eye wear and gloves. Address chemicals that pose specific toxicity or safety concerns and follow any chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. other relevant requirements, as appropriate. Procedural Precautionsal Precautions 1.2.2.11.2.2.1 All field turbidityAll field turbidity recorded in the field logbook for the event. All records should be entered recorded in the field logbook for the event. All records should be entered Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 4 of 12 LSASDPROC-103-R5 110321 2.2. The ambient temperature in the immediate vicinity of the meter should be measured and recorded in the field logbook to ensure the instrument is operated within the manufacturer’s specified range of operating temperatures. For instruments that are deployed for in-situ measurements, the temperature of the medium being monitored should be measured and recorded in the logbook prior to deployment. In-situ monitoring equipment may be utilized in unattended deployments where autonomous logging may preclude temperature measurement prior to deployment. Because in situ instrumentation generally has a wide range of operating temperature, the field investigator may utilize professional judgment in determining if the operating environment is suitable for unattended deployment. 2.3. If at any time during a field investigation, it appears that the environmental conditions could jeopardize the quality of the measurement results, the measurements will be stopped. This will be documented in the field logbook. 3. Field Turbidity Measurement Procedures 3.1. General 3.1.1. Turbidity is caused by suspended and colloidal matter such as clay, silt, organic and inorganic matter and microscopic organisms. Many methods are available for the measurement of turbidity including turbidimeters and optical probes. Turbidity is measured by determining the amount of scatter when a light is passed through a sample. 3.2. Instrument Calibration and Verification 3.2.1. Many brands of instruments are commercially available for the measurement of turbidity incorporating a wide variety of technologies (See Section 3.5 for further discussion). The manufacturer’s instruction manual should be consulted for specific procedures regarding their calibration, maintenance and use. Calibration of any measurement instrument must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate. Depending on the instrument, the verification and calibration can differ slightly. If the instrument readings do not agree within ± 10 % of the calibration standards, the unit must be recalibrated, repaired or replaced. The following are basic guidelines for calibration/verification of meters and are provided as an example: could jeopardize the quality of the measurement results, the measurements will be could jeopardize the quality of the measurement results, the measurements will be Turbidity is caused by suspended and colloidal matter such as clay, silt, organic Turbidity is caused by suspended and colloidal matter such as clay, silt, organic and inorganic matter and microscopic organisms. Many methods are available for and inorganic matter and microscopic organisms. Many methods are available for the measurement of turbidity including turbidimeters and opticthe measurement of turbidity including turbidimeters and optic by determining the amount of scatter when a light is passed through a by determining the amount of scatter when a light is passed through a and Verificationand Verification Many brands of instruments are commercially available for the measurement of Many brands of instruments are commercially available for the measurement of turbidity incorporating a wide variety of technologies turbidity incorporating a wide variety of technologies discussion). The manufacturer’s instruction manual should be consulted for specific discussion). The manufacturer’s instruction manual should be consulted for specific procedures regarding their calibration, maintenance and use. Calibration of any procedures regarding their calibration, maintenance and use. Calibration of any measurement instrument must be cmeasurement instrument must be c daily basis, whichever is most appropriate. Depending on the instrument, the daily basis, whichever is most appropriate. Depending on the instrument, the verification and calibration can differ slightly. If the instrument readings do not verification and calibration can differ slightly. If the instrument readings do not agree within ± 10 % of the calibration standards, the unit must be recalibrated, Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 5 of 12 LSASDPROC-103-R5 110321 3.2.2. Meter Calibration and Verification 3.2.1.1 HACH 2100Q Turbidimeter: Portable turbidimeters are calibrated with Formazin Primary Standards. The manufacturer recommends calibration with a primary standard such as StablCal® Stabilized Standards or with formazin standards every three months. Generally only a calibration verification measurement is required in the field; however, if a calibration is needed, record a post calibration reading for each calibration standard used. 3.2.1.2 Meter Verification: Push Verify Cal to enter the Verify menu. Gently invert the liquid standard several times prior to insertion into meter. Insert the 10.0 NTU (or other defined value) Verification Standard and close the lid. Push Read. The display shows “Stabilizing” and then shows the result and tolerance range. Push Done to return to the reading display. Repeat the calibration verification if the verification failed. If a meter is unable to pass verification, then that meter will need to be calibrated. 3.2.1.3 Meter Calibration: Push the CALIBRATION key to enter the Calibration mode. Follow the instructions on the display. Note: Gently invert each standard several times before inserting the standard and use a non-abrasive, lint-free paper or cloth to wipe off the standards. Insert the 20 NTU StablCal Standard and close the lid. Push Read. The display shows “Stabilizing” and then shows the result. Record the result. Repeat Step 2 with the 100 NTU and 800 NTU StablCal Standard. Record both results. Push Done to review the calibration details. Push Store to save the results. After a calibration is complete, the meter automatically goes into the Verify Cal mode. to enter the Verify menu. Gently invert the liquid standard several times prior to insertion into Gently invert the liquid standard several times prior to insertion into Insert the 10.0 NTU (or other defined value) Verification Standard Insert the 10.0 NTU (or other defined value) Verification Standard . The display shows “Stabilizing” and then shows the result and . The display shows “Stabilizing” and then shows the result and Push Done to return to the reading display. Repeat the calibration Push Done to return to the reading display. Repeat the calibration verification if theverification if the verification failed. verification failed. verification, then that meter will need to be calibrated.verification, then that meter will need to be calibrated. Meter CalibrationMeter Calibration Push the Push the instructions on the display. Note: Gently invert each standard instructions on the display. Note: Gently invert each standard times times Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 6 of 12 LSASDPROC-103-R5 110321 3.2.2 Probe Calibration and Verification 3.2.2.1 The manufacturer’s instruction manual should be consulted for specific procedures regarding probe’s calibration, maintenance and use. Their calibration must be conducted and/or verified prior to each use or on a daily basis, whichever is most appropriate. The following are basic guidelines for calibration/verification of probes and are provided as an example: Turn the meter “ON” and allow it to stabilize Immerse the probe in the first standard solution and calibrate the probe against the solution. Rinse the probe with de-ionized water, remove excess rinse water and calibrate the probe using additional standards as appropriate. Record the standard values used to calibrate the meter. 3.3 Sample Measurement Procedures 3.3.1 Depending on the meter, the sample measurement procedure can differ slightly. 3.3.2 Grab Sample Measurement 3.3.2.1 These procedures should be followed when conducting turbidity measurements of grab samples: Collect a representative sample and pour off enough to fill the cell to the fill line (about 15 mL) and replace the cap on the cell. Gently wipe off excess water and any streaks from surface of sampling vial. Turn instrument on. Place the meter on a flat, sturdy surface. Do not hold the instrument while making measurements. Insert the sample cell in the instrument so the diamond or orientation mark aligns with the raised orientation mark in the front of the cell compartment. Close the lid. If appropriate, select manual or automatic range selection by pressing the range key. If appropriate, select signal averaging mode by pressing the Signal Average key. Use signal average mode if the sample causes a noisy signal (display changes constantly). ionized water, remove excess rinse water and ionized water, remove excess rinse water and calibrate the probe using additional standards as appropriate. calibrate the probe using additional standards as appropriate. Record the standard values used to calibrate the meter.Record the standard values used to calibrate the meter. Depending on the meter, the sample measurement procedure can differ slightly. Depending on the meter, the sample measurement procedure can differ slightly. These procedures should be followed when conducting turbidity These procedures should be followed when conducting turbidity measurements of grab samples:measurements of grab samples: Collect a representative sample and pour off enough to fill the cell to the Collect a representative sample and pour off enough to fill the cell to the fill line (about 15 mL) and replace the cap on the cell. fill line (about 15 mL) and replace the cap on the cell. Gently wGently wipe off excess water and any streaks ipe off excess water and any streaks vial.vial. Turn instrument on. Place the meter on a flat, sturdy surface. Do not hold Turn instrument on. Place the meter on a flat, sturdy surface. Do not hold the instrument while making measurements.the instrument while making measurements. Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 7 of 12 LSASDPROC-103-R5 110321 Press Read. The display will show ---- NTU. Then the turbidity is displayed in NTU. Record the result to the correct range dependent significant digits as required by EPA Method 180.1 Rev. 2.0 (USEPA, 1993) and SM 2130B (APHA, 1992) (Table 1). Rinse the cell with de-ionized water or rinse out with sample water prior to the next reading. Table 1: Reporting Requirements (APHA, 1992) 3.3.3 In-Situ Measurement 3.3.3.1 These procedures should be followed when conducting in-situ turbidity measurements: Place the probe into the media to be measured and allow the turbidity reading to stabilize. Once the reading has stabilized, record the measurement in the logbook. When deploying meters for extended periods of time, ensure the measurement location is representative of average media conditions. 3.4 Operational check 3.4.1 Even though it is not necessary to re-calibrate turbidity meters at regular intervals during the day, depending on the instrument, it may be appropriate to occasionally perform operational checks to determine if site conditions, such as an increase in temperature, have impacted the meter’s performance. If an operational check is warranted, the following procedure should be followed to ensure that the performance of the meter has not changed. These procedures should be followed when conducting These procedures should be followed when conducting measurements:measurements: Place the probe into the media to be measured and allow the turbidity Place the probe into the media to be measured and allow the turbidity readingreading to stabilize. Once the reading has stabilized, record the to stabilize. Once the reading has stabilized, record the measurement in the logbook. measurement in the logbook. When deploying meters for extended periods of time, ensure the When deploying meters for extended periods of time, ensure the Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 8 of 12 LSASDPROC-103-R5 110321 3.4.2 While in use, periodically check the turbidity by rinsing the probe with de- ionized water, blot dry or otherwise remove excess rinse water and immerse it into the appropriate calibration standard. If the measured turbidity differs by ± 10 % (depending on the application) from the calibration standard, the meter must be re-calibrated. 3.4.3 A post-operation instrument verification check will be performed using the appropriate standard(s) at the end of the day or after all measurements have been taken for a particular period of operation. These measurements must be recorded in the field logbook. 3.5 Units and Application 3.5.1 Due to the availability of various technologies for measuring turbidity, the USGS (United States Geological Survey) in collaboration with ASTM International (American Society for Testing and Materials) has determined that data collected using different methods are not directly comparable and should be reported in units reflecting the specific technology used (USGS 2004; ASTM International 2012) (Table 2). 3.5.2 Measurements taken for regulatory purposes (i.e., National Primary Drinking Water Regulations (NPDWR) monitoring, National Pollution Discharge Elimination System (NPDES) reporting) must be in compliance with EPA approved methods. Approved methods for Clean Water Act programs and Safe Drinking Water Act programs can be found in 40 C.F.R. § 136.3 and 40 C.F.R. § 141.74(a)(1), respectively. 3.5.3 Project leaders should consult the decision tree depicted in Figure 1 to determine the appropriate turbidity method that will meet the project specific Data Quality Objectives. For more detailed information on the different methods and their associated units, refer to the USGS National Field Manual for the Collection of Water-Quality Data, Section 6.7 (USGS 2005) and ASTM designation D7315 (ASTM International 2012). A sensor specific spreadsheet detailing methods and associated units can be found on the USGS Field Manual website under turbidity parameter and methods codes (USGS 2012). Due to the availability of various technologies for measuring turbidity, thDue to the availability of various technologies for measuring turbidity, th (United States Geological Survey) in collaboration with ASTM (United States Geological Survey) in collaboration with ASTM American Society for Testing and MaterialsAmerican Society for Testing and Materials) has determined that ) has determined that data collected using different methods are not directly comparable and should data collected using different methods are not directly comparable and should be reported in units reflecting the specific technology used (USGS 2004be reported in units reflecting the specific technology used (USGS 2004 Measurements taken for regulatory purposes (i.e., National Primary Drinking Measurements taken for regulatory purposes (i.e., National Primary Drinking ) monitoring, National Pollution Discharge ) monitoring, National Pollution Discharge S) reporting) must be in compliance with EPA S) reporting) must be in compliance with EPA approved methods. Approved methods for Clean Water Act programs and Safe approved methods. Approved methods for Clean Water Act programs and Safe Drinking Water Act programs can be found in 40 C.F.R. § 136.3 and 40 C.F.R. Drinking Water Act programs can be found in 40 C.F.R. § 136.3 and 40 C.F.R. , respectively., respectively. Project leaders should consult Project leaders should consult determine the appropriate turbidity method that will meet the project specific determine the appropriate turbidity method that will meet the project specific Data Quality ObjectivesData Quality Objectives methods and their associated units, refer to the USGS National methods and their associated units, refer to the USGS National for the Collection of Water-Quality Data, Section 6.7 (USGS 2005) and ASTM for the Collection of Water-Quality Data, Section 6.7 (USGS 2005) and ASTM designation D7315 (designation D7315 ( detailing methods and associated units can be found on the USGS Field Manual detailing methods and associated units can be found on the USGS Field Manual website under turbidity parameter and methods codes (USGS 2012 Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 9 of 12 LSASDPROC-103-R5 110321 References APHA (1992). Turbidity: Method 2130B. Standard Methods for the Examination of Water and Wastewater, 18th Edition, pp. 2-11. ASTM International (2012). D7315-12 Standard test method for determination of turbidity above 1 turbidity unit in static mode: ASTM International, Annual Book of Standards, Water and Environmental Technology, v. 11.01, West Conshohocken, Pennsylvania. LSASD Operating Procedure for Equipment Inventory and Management, LSASDPROC-108, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version USEPA (1993). Method 180.1: Determination of Turbidity by Nephelometry. Rev. 2.0. Environmental Systems Monitoring Laboratory, Office of Research and Development, Cincinnati, Ohio. USEPA (2001). Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Science and Ecosystem Support Division (SESD), Athens, GA. USEPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version USGS (2004). Office of Water Quality Technical Memorandum 2004.03: Revision of NFM Chapter 6, Section 6.7- Turbidity, available online at: http://water.usgs.gov/admin/memo/QW/qw04.03.html USGS (2005). National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A6.7, available online at http://pubs.water.usgs.gov/twri9A. USGS (2012). Turbidity parameter and methods codes, available online at: https://water.usgs.gov/owq/turbidity/Turbidity_parameter_codes_and_methods_codes_(May201 2)%20(2).xlsx LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version LSASD Operating Procedure for Logbooks, LSASDPROC-010, Most Recent Version USEPA (1993). Method 180.1: Determination of Turbidity by Nephelometry. Rev. 2.0. USEPA (1993). Method 180.1: Determination of Turbidity by Nephelometry. Rev. 2.0. Environmental Systems Monitoring Laboratory, Office of Research and Development, Environmental Systems Monitoring Laboratory, Office of Research and Development, USEPA (2001). Environmental Investigations Standard Operating Procedures and Quality USEPA (2001). Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Science and Ecosystem Support Division (SESD), Athens, GA. Assurance Manual. Region 4 Science and Ecosystem Support Division (SESD), Athens, GA. USEPA. Safety, Health and Environmental Management Program Procedures and Policy USEPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version Manual. Region 4 LSASD, Athens, GA, Most Recent Version USGS (2004). Office of Water Quality Technical Memorandum 2004.03: Revision of NFM USGS (2004). Office of Water Quality Technical Memorandum 2004.03: Revision of NFM Chapter 6, Section 6.7- Turbidity, available online at: Chapter 6, Section 6.7- Turbidity, available online at: http://water.usgs.gov/admin/memo/QW/qw04.03.html http://water.usgs.gov/admin/memo/QW/qw04.03.html USGS (2005). National field manual for the collection of water-quality data: U.S. Geological USGS (2005). National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A6.7, available online at Survey Techniques of Water-Resources Investigations, book 9, chaps. A6.7, available online at http://pubs.water.usgs.gov/twri9A. http://pubs.water.usgs.gov/twri9A. USGS (2012). Turbidity parameter and methods codes, available online at: USGS (2012). Turbidity parameter and methods codes, available online at: https://water.usgs.gov/owq/turbidity/Turbidity_parameter_codes_and_methods_codes_(May201 Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 10 of 12 LSASDPROC-103-R5 110321 Revision History History Effective Date LSASDPROC-103-R5, Field Turbidity Measurement, replaces LSASDPROC-103-R4 Title Page: Changed the author from Timothy Simpson to Michael Roberts. Changed the Field Services Branch Chief from John Deatrick to Sandra Aker. Deleted Hunter Johnson the as Field Quality Manager. Replaces SESD with LSASD LSASDPROC-103-R4, Field Turbidity Measurement, replaces LSASDPROC-103-R3 General: Added to Section 3.6 to include application of various turbidity units and associated methods relative to various applications. Title Page: Changed Enforcement and Investigations Branch to the Field Services Branch and changed the Chief from Danny France to John Deatrick. Changed Field Quality Manager from Bobby Lewis to Hunter Johnson. Section 1.4: Added new references cited in Section 3.5 Section 3.2: Added reference to Section 3.5 Section 3.3.1: Added Table 1 outlining reporting requirements. Section 3.5: Introduced different turbidity units associated with various methods and stated importance of using EPA approved methods for regulatory purposes. Also added Figure 1, a decision tree to assist project leaders in selecting the appropriate method to satisfy Data Quality Objectives, and Table 2, outlining technologies, associated units, application, and design. November 03, 2021 July 27, 2017 LSASDPROC-103-R3, Field Turbidity Measurement, replaces LSASDPROC-103-R2 January 29, 2013 LSASDPROC-103-R2, Field Turbidity Measurement, replaces LSASDPROC-103-R1 June 13, 2008 LSASDPROC-103-R1, Field Turbidity Measurement, replaces LSASDPROC-103-R0 November 1, 2007 LSASDPROC-103-R0, Field Turbidity Measurement, Original Issue February 05, 2007 General: Added to Section 3.6 to include application of various General: Added to Section 3.6 to include application of various Title Page: Changed Enforcement and Investigations Branch to the Title Page: Changed Enforcement and Investigations Branch to the Field Services Branch and changed the Chief from Danny France to Field Services Branch and changed the Chief from Danny France to John Deatrick. Changed Field Quality Manager from Bobby Lewis John Deatrick. Changed Field Quality Manager from Bobby Lewis Section 1.4: Added new references cited in Section 1.4: Added new references cited in Section 3.5 Section 3.5 Section 3.2: Added reference to Section 3.5 Section 3.2: Added reference to Section 3.5 Section 3.3.1: Added Table 1 outlining reporting requirements. Section 3.3.1: Added Table 1 outlining reporting requirements. Section 3.5: Introduced different turbidity units associated with Section 3.5: Introduced different turbidity units associated with various methods and stated importance of using EPA approved various methods and stated importance of using EPA approved methods for regulatory purposes. Also added Figure 1, a decision methods for regulatory purposes. Also added Figure 1, a decision tree to assist project leaders in selecting the appropriate methotree to assist project leaders in selecting the appropriate metho satisfy Data Quality Objectives, and Table 2, outlining technologies, satisfy Data Quality Objectives, and Table 2, outlining technologies, November 03, 2021 November 03, 2021 Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 11 of 12 LSASDPROC-103-R5 110321 Figure 1: Turbidity Method Decision Tree, adapted from Figure 6.7-2 (USGS 2005) Field Turbidity Measurements Effective Date: November 3, 2021 Approved by HWS Chief Page 12 of 12 LSASDPROC-103-R5 110321 Table 2: Turbidity Technology, Units, Application, & Design (adapted from ASTM International 2012) APPENDIX D EQUIPMENT DECONTAMINATION PROCEDURES LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 1 of 15 Purpose This procedure is to be used by Region 4 Laboratory Services and Applied Science Division staff . This document describes general and specific procedures, methods and considerations to be used and observed when cleaning and decontaminating sampling equipment during the course of field investigations. This procedure is to be used by all Region 4 Laboratory Services and Applied Science Division (LSASD) staff. Scope/Application The procedures contained in this document are to be followed when field cleaning sampling equipment, for both re-use in the field, as well as used equipment being returned to the Field Equipment Center (FEC). On the occasion that LSASD field investigators determine that any of the procedures described in this section are either inappropriate, inadequate or impractical and that other procedures must be used to clean or decontaminate sampling equipment at a particular site, the variant procedure will be documented in the field logbook, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Field Equipment Cleaning and Decontamination ID: LSASDPROC-205-R4 Issuing Authority: LSASD Field Branch Chief Effective Date: June 22, 2020 Review Due Date: June 22, 2023 Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 2 of 15 TABLE OF CONTENTS Purpose 1 Scope/Application ....................................................................................................................... 1 1 General Information ................................................................................................................ 3 1.1 Documentation/Verification ............................................................................................ 3 1.2 Definitions ....................................................................................................................... 3 1.3 General Precautions ........................................................................................................ 4 1.3.1 Safety ...................................................................................................................... 4 1.3.2 Procedural Precaution ............................................................................................. 4 2 Introduction to Field Equipment Cleaning and Decontamination .......................................... 4 2.1 General ............................................................................................................................ 4 2.2 Handling Practices and Containers for Cleaning Solutions ............................................ 4 2.4 Sample Collection Equipment Contaminated with Concentrated Materials ................... 5 2.5 Sample Collection Equipment Contaminated with Environmental Media ..................... 5 2.6 Handling of Decontaminated Equipment ........................................................................ 6 3 Field Equipment Decontamination Procedures ...................................................................... 6 3.1 General ............................................................................................................................ 6 3.2 Specifications for Decontamination Pads ....................................................................... 6 3.3 "Classical Parameter" Sampling Equipment ................................................................... 7 3.4 Sampling Equipment used for the Collection of Trace Compounds .............................. 7 3.5 Well Sounders or Tapes .................................................................................................. 8 3.6 Redi-Flo2® Pump ............................................................................................................ 8 3.6.1 Purge Only (Pump and Wetted Portion of Tubing or Hose) ................................... 8 3.6.2 Purge And Sample .................................................................................................. 8 3.6.3 Redi-Flo2® Ball Check Valve ................................................................................. 9 3.7 Mega-Monsoon® and GeoSub® Electric Submersible Pump ........................................ 10 3.8 Bladder Pumps .............................................................................................................. 10 3.9 Downhole Drilling Equipment ...................................................................................... 10 3.9.1 Introduction ........................................................................................................... 10 3.9.2 Preliminary Cleaning and Inspection .................................................................... 11 3.9.3 Drill Rig Field Cleaning Procedure ...................................................................... 11 3.9.4 Field Decontamination Procedure for Drilling Equipment ................................... 11 3.9.5 Field Decontamination Procedure for Direct Push Technology (DPT) ................ 12 3.10 Rental Pumps ................................................................................................................ 13 4 References .............................................................................................................................. 13 Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 3 of 15 1 General Information 1.1 Documentation/Verification This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and have been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD Local Area Network (LAN). The Document Control Coordinator (DCC) is responsible for ensuring the most recent version of the procedure is placed on LAN and for maintaining records of review conducted prior to its issuance. 1.2 Definitions • Decontamination: The process of cleaning dirty sampling equipment to the degree to which it can be re-used, with appropriate QA/QC, in the field. • Deionized water: Tap water that has been treated by passing through a standard deionizing resin column. At a minimum, the finished water should contain no detectable heavy metals or other inorganic compounds (i.e., at or above analytical detection limits) as defined by a standard inductively coupled Argon Plasma Spectrophotometer (ICP) (or equivalent) scan. Deionized water obtained by other methods is acceptable, as long as it meets the above analytical criteria. Organic-free water may be substituted for deionized water. • Detergent shall be a standard brand of phosphate-free laboratory detergent such as Liquinox® or Luminox®. Liquinox® is a traditional anionic laboratory detergent and is used for general cleaning and where there is concern for the stability of the cleaned items in harsher cleaners. Luminox® is a specialized detergent with the capability of removing oils and organic contamination. It is used in lieu of a solvent rinse step in cleaning of equipment for trace contaminant sampling. Where not specified in these procedures, either detergent is acceptable. • Drilling Equipment: All power equipment used to collect surface and sub-surface soil samples or install wells. For purposes of this procedure, direct push is also included in this definition. • Field Cleaning: The process of cleaning dirty sampling equipment such that it can be returned to the FEC in a condition that will minimize the risk of transfer of contaminants from a site. • Organic-free water: Tap water that has been treated with activated carbon and deionizing units. At a minimum, the finished water must meet the analytical criteria of deionized water and it should contain no detectable pesticides, herbicides, or extractable organic compounds, and no volatile organic compounds above minimum detectable levels as determined by the Region 4 laboratory for a given set of analyses. Organic-free water obtained by other methods is acceptable, as long as it meets the above analytical criteria. • Tap water: Water from any potable water supply. Deionized water or organic-free water may be substituted for tap water. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 4 of 15 1.3 General Precautions 1.3.1 Safety Proper safety precautions must be observed when field cleaning or decontaminating dirty sampling equipment. Refer to the LSASD Safety, Health and Environmental Management Program (SHEMP) Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. At a minimum, the following precautions should be taken in the field during these cleaning operations: • When conducting field cleaning or decontamination using laboratory detergent, safety glasses with splash shields or goggles, and latex gloves will be worn. • No eating, smoking, drinking, chewing, or any hand to mouth contact should be permitted during cleaning operations. 1.3.2 Procedural Precaution Prior to mobilization to a site, the expected types of contamination should be evaluated to determine if the field cleaning and decontamination activities will generate rinses and other waste waters that might be considered RCRA hazardous waste or may require special handling. 2 Introduction to Field Equipment Cleaning and Decontamination 2.1 General The procedures outlined in this document are intended for use by field investigators for cleaning and decontaminating sampling and other equipment in the field. These procedures should be followed in order that equipment is returned to the FEC in a condition that will minimize the risk of transfer of contaminants from a site. Sampling and field equipment cleaned in accordance with these procedures must meet the minimum requirements for the Data Quality Objectives (DQOs) of the study or investigation. If deviations from these procedures need to be made during the course of the field investigation, they will be documented in the field logbook along with a description of the circumstances requiring the use of the variant procedure. Cleaning procedures for use at the Field Equipment Center (FEC) are found in LSASD Operating Procedure for Equipment Cleaning and Decontamination at the FEC (LSASDPROC-206). 2.2 Handling Practices and Containers for Cleaning Solutions Improperly handled cleaning solutions may easily become contaminated. Storage and application containers must be constructed of the proper materials to ensure their integrity. Following are acceptable materials used for containing the specified cleaning solutions: Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 5 of 15 • Detergent must be kept in clean plastic, metal, or glass containers until used. It should be poured directly from the container during use. • Tap water may be kept in tanks, hand pressure sprayers, squeeze bottles, or applied directly from a hose. • Deionized water must be stored in clean, glass or plastic containers that can be closed for transport. It can be applied from plastic squeeze bottles. • Organic-free water must be stored in clean glass or Teflon® containers prior to use. It may be applied using Teflon® squeeze bottles, or with the portable system. 2.3 Disposal of Cleaning Solutions Procedures for the safe handling and disposition of investigation derived waste (IDW); including used wash water and rinse water are in LSASD Operating Procedure for Management of Investigation Derived Waste (LSASDPROC-202). 2.4 Sample Collection Equipment Contaminated with Concentrated Materials Equipment used to collect samples of concentrated materials from investigation sites must be field cleaned before returning from the study. At a minimum, this should consist of washing with detergent and rinsing with tap water. When the above procedure cannot be followed, the following options are acceptable: • Leave with facility for proper disposal; • If possible, containerize, seal, and secure the equipment and leave on-site for later disposal; • Containerize, bag, or seal the equipment so that no odor is detected and return to the Field Equipment Center. It is the project leader’s responsibility to evaluate the nature of the sampled material and determine the most appropriate cleaning procedures for the equipment used to sample that material. 2.5 Sample Collection Equipment Contaminated with Environmental Media Equipment used to collect samples of environmental media from investigation sites should be field cleaned before returning from the study. Based on the condition of the sampling equipment, one or more of the following options must be used for field cleaning: • Wipe the equipment clean; • Water-rinse the equipment; • Wash the equipment in detergent and water followed by a tap water rinse. • For grossly contaminated equipment, the procedures set forth in Section 2.4 must be followed. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 6 of 15 Under extenuating circumstances such as facility limitations, regulatory limitations, or during residential sampling investigations where field cleaning operations are not feasible, equipment can be containerized, bagged or sealed so that no odor is detected and returned to the FEC without being field cleaned. If possible, FEC personnel should be notified that equipment will be returned without being field cleaned. It is the project leader’s responsibility to evaluate the nature of the sampled material and determine the most appropriate cleaning procedures for the equipment used to sample that material. 2.6 Handling of Decontaminated Equipment After decontamination, equipment should be handled only by personnel wearing clean gloves to prevent re-contamination. In addition, the equipment should be moved away (preferably upwind) from the decontamination area to prevent re-contamination. If the equipment is not to be immediately re-used, it should be covered with plastic sheeting or wrapped in aluminum foil to prevent re-contamination. The area where the equipment is kept prior to re-use must be free of contaminants. 3 Field Equipment Decontamination Procedures 3.1 General Sufficient equipment should be transported to the field so that an entire study can be conducted without the need for decontamination. When equipment must be decontaminated in the field, the following procedures are to be utilized. Note: Equipment utilized for PFAS sampling will not cleaned in the field. 3.2 Specifications for Decontamination Pads Decontamination pads constructed for field cleaning of sampling and drilling equipment should meet the following minimum specifications: • The pad should be constructed in an area known or believed to be free of surface contamination. • The pad should not leak. • If possible, the pad should be constructed on a level, paved surface and should facilitate the removal of wastewater. This may be accomplished by either constructing the pad with one corner lower than the rest, or by creating a sump or pit in one corner or along one side. Any sump or pit should also be lined. • Sawhorses or racks constructed to hold equipment while being cleaned should be high enough above ground to prevent equipment from being splashed. • Water should be removed from the decontamination pad frequently. • A temporary pad should be lined with a water impermeable material with no seams within the pad. This material should be either easily replaced (disposable) or repairable. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 7 of 15 At the completion of site activities, the decontamination pad should be deactivated. The pit or sump should be backfilled with the appropriate material designated by the site project leader, but only after all waste/rinse water has been pumped into containers for disposal. See LSASD Operating Procedure for Management of Investigation Derived Waste (LSASDPROC-202) for proper handling and disposal of these materials. If the decontamination pad has leaked excessively, soil sampling may be required. 3.3 "Classical Parameter" Sampling Equipment "Classical Parameters" are analyses such as oxygen demand, nutrients, certain inorganic compounds, sulfide, flow measurements, etc. For routine operations involving classical parameter analyses, water quality sampling equipment such as Kemmerers, buckets, dissolved oxygen dunkers, dredges, etc., may be cleaned with the sample water or tap water between sampling locations as appropriate. Flow measuring equipment such as weirs, staff gages, velocity meters, and other stream gauging equipment may be cleaned with tap water between measuring locations, if necessary. Note: The procedures described in Section 3.3 are not to be used for cleaning field equipment to be used for the collection of samples undergoing trace organic or inorganic constituent analyses. 3.4 Sampling Equipment used for the Collection of Trace Organic and Inorganic Compounds For samples undergoing trace organic or inorganic constituent analyses, the following procedures are to be used for all sampling equipment or components of equipment that come in contact with the sample: 3.4.1 Standard LSASD Method • An optional Liquinox® detergent wash step may be useful to remove gross dirt and soil. • Clean with tap water and Luminox® detergent using a brush, if necessary, to remove particulate matter and surface films. • Rinse thoroughly with tap water. • Rinse thoroughly with organic-free water and place on a clean foil-wrapped surface to air- dry. • Wrap the dry equipment with aluminum foil or bag in clean plastic. If the equipment is to be stored overnight before it is wrapped in foil, it should be covered and secured with clean, unused plastic sheeting. 3.4.2 Alternative Solvent Rinse Method The historical solvent rinse method of cleaning equipment for trace contaminant sampling remains an acceptable method. • Clean with tap water and Liquinox® detergent using a brush, if necessary, to remove particulate matter and surface films. Equipment may be steam cleaned (Liquinox® detergent and high-pressure hot water) as an alternative to brushing. Sampling equipment that is steam cleaned should be placed on racks or saw horses at least two feet above the floor of the decontamination pad. PVC or plastic items should not be steam cleaned. • Rinse thoroughly with tap water. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 8 of 15 • Rinse thoroughly with deionized water. • Rinse with an appropriate solvent (generally isopropanol). • Rinse with organic-free water and place on a clean foil-wrapped surface to air-dry. • Wrap the dry equipment with aluminum foil or plastic. If the equipment is to be stored overnight before it is wrapped, it should be covered and secured with clean, unused plastic sheeting. 3.5 Well Sounders or Tapes The following procedures are recommended for decontaminating well sounders (water level indicators) and tapes. Unless conditions warrant, it is only necessary to decontaminate the wetted portion of the sounder or tape. • Wash with Liquinox® detergent and tap water. • Rinse with tap water. • Rinse with deionized water. 3.6 Redi-Flo2® Pump CAUTION – Do not wet the controller. Always disconnect power from the pump when handling the pump body. The Redi-Flo2® pump and any associated connected hardware (e.g., check valve) should be decontaminated between each monitoring well. The following procedures are required, depending on whether the pump is used solely for purging or used for purging and sampling. 3.6.1 Purge Only (Pump and Wetted Portion of Tubing or Hose) • Disconnect power and wash exterior of pump and wetted portion of the power lead and tubing or hose with Liquinox® detergent and water solution. • Rinse with tap water. • Final rinse with deionized water. • Place pump and reel in a clean plastic bag and keep tubing or hose contained in clean plastic or galvanized tub between uses. 3.6.2 Purge And Sample Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 9 of 15 Grundfos Redi-Flo2® pumps are extensively decontaminated and tested at the FEC to prevent contamination from being transmitted between sites. The relevant sections of LSASDPROC-206, Field Equipment Cleaning and Decontamination at the FEC, should be implemented in the field where a high risk of cross-contamination exists, such as where NAPL or high-concentration contaminants occur. In most cases, the abbreviated cleaning procedure described below will suffice, provided that sampling proceeds from least to most contaminated areas. • Disconnect and discard the previously used sample tubing from the pump. Remove the check valve and tubing adapters and clean separately (See Section 3.6.3 for check valve). Wash the pump exterior with detergent and water. • Prepare and fill three containers with decontamination solutions, consisting of Container #1, a tap water/detergent washing solution. Luminox® is commonly used. An additional pre-wash container of Liquinox® may be used; Container #2, a tap water rinsing solution; and Container #3, a deionized or organic-free water final rinsing solution. Choice of detergent and final rinsing solution for all steps in this procedure is dependent upon project objectives (analytes and compounds of interest). The containers should be large enough to hold the pump and one to two liters of solution. An array of 2’ long 2” PVC pipes with bottom caps is a common arrangement. The solutions should be changed at least daily. • Place the pump in Container #1. Turn the pump on and circulate the detergent and water solution through the pump and then turn the pump off. • Place the pump in Container #2. Turn the pump on and circulate the tap water through the pump and then turn the pump off. • Place the pump in Container #3. Turn the pump on and circulate deionized or organic-free water through the pump and then turn the pump off. • Disconnect power and remove pump from Container #3. Rinse exterior and interior of pump with fresh deionized or organic-free water. • Decontaminate the power lead by washing with detergent and water, followed by tap water and deionized water rinses. This step may be performed before washing the pump if desired. • Reassemble check valve and tubing adapters to pump. ALWAYS use Teflon® tape to prevent galling of threads. Firm hand-tightening of fittings or light wrench torque is generally adequate. • Place the pump and reel in a clean plastic bag. 3.6.3 Redi-Flo2® Ball Check Valve • Remove the ball check valve from the pump head. Check for wear and/or corrosion, and replace as needed. During decontamination check for free-flow in forward direction and blocking of flow in reverse direction. • Using a brush, scrub all components with detergent and tap water. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 10 of 15 • Rinse with deionized water. • Rethread the ball check valve to the Redi-Flo2® pump head. 3.7 Mega-Monsoon® and GeoSub® Electric Submersible Pump As these pumps have lower velocities in the turbine section and are easier to disassemble in the field than Grundfos pumps, the outer pump housing should be removed to expose the impeller for cleaning prior to use and between each use when used as a sampling pump for trace contaminant sampling. • Remove check valves and adapter fittings and clean separately. • Remove the outer motor housing by holding the top of the pump head and unscrewing the outer housing from its O-ring sealed seat. • Clean all pump components per the provisions of section 3.4. Use a small bottle brush for the pump head passages • Wet the O-ring(s) on the pump head with organic-free water. Reassemble the outer pump housing to the pump head. • Clean cable and reel per Section 3.4. • Conduct final rinse of pump with organic-free water over pump and through pump turbine. 3.8 Bladder Pumps Bladder pumps are presumed to be intended for use as low flow purge-and-sample pumps. The Geotech® bladder pump and Geoprobe Systems® mechanical bladder pump can be cleaned similarly. • Discard any tubing returned with the pump. • Completely disassemble the pump, being careful to note the initial position of and retain any springs and loose ball checks. • Discard pump bladder. • Clean all parts as per the standard cleaning procedure in Section 3.4. • Install a new Teflon® bladder and reassemble pump. 3.9 Downhole Drilling Equipment While LSASD does not currently operate drilling equipment, LSASD personnel do oversee and specify drilling operations. The following procedures are to be used for drilling activities involving the collection of soil samples for trace organic and inorganic constituent analyses and for the construction of monitoring wells to be used for the collection of groundwater samples for trace organic and inorganic constituent analyses. 3.9.1 Introduction Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 11 of 15 Cleaning and decontamination of all equipment should occur at a designated area (decontamination pad) on the site. The decontamination pad should meet the specifications of Section 3.2 of this procedure. Tap water brought on the site for drilling and cleaning purposes should be contained in a pre- cleaned tank. A steam cleaner and/or high pressure hot water washer capable of generating a pressure of at least 2500 PSI and producing hot water and/or steam, with a detergent compartment, should be obtained. 3.9.2 Preliminary Cleaning and Inspection Drilling equipment should be clean of any contaminants that may have been transported from off- site to minimize the potential for cross-contamination. The drilling equipment should not serve as a source of contaminants. Associated drilling and decontamination equipment, well construction materials, and equipment handling procedures should meet these minimum specified criteria: • All downhole augering, drilling, and sampling equipment should be sandblasted before use if painted, and/or there is a buildup of rust, hard or caked matter, etc., that cannot be removed by steam cleaning (detergent and high pressure hot water), or wire brushing. Sandblasting should be performed prior to arrival on site, or well away from the decontamination pad and areas to be sampled. • Any portion of the drilling equipment that is over the borehole (kelly bar or mast, backhoe buckets, drilling platform, hoist or chain pulldowns, spindles, cathead, etc.) should be steam cleaned (detergent and high pressure hot water) and wire brushed (as needed) to remove all rust, soil, and other material which may have come from other sites before being brought on site. • Printing and/or writing on well casing, tremie tubing, etc., should be removed before use. Emery cloth or sand paper can be used to remove the printing and/or writing. Most well material suppliers can provide materials without the printing and/or writing if specified when ordered. Items that cannot be cleaned are not acceptable and should be discarded. • Equipment associated with the drilling and sampling activities should be inspected to insure that all oils, greases, hydraulic fluids, etc., have been removed, and all seals and gaskets are intact with no fluid leaks. 3.9.3 Drill Rig Field Cleaning Procedure Any portion of the drill rig, backhoe, etc., that is over the borehole (kelly bar or mast, backhoe buckets, drilling platform, hoist or chain pulldowns, spindles, cathead, etc.) should be steam cleaned (detergent and high pressure hot water) between boreholes. 3.9.4 Field Decontamination Procedure for Drilling Equipment Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 12 of 15 The following is the standard procedure for field cleaning augers, drill stems, rods, tools, and associated equipment. This procedure does not apply to well casings, well screens, or split-spoon samplers used to obtain samples for chemical analyses, which should be decontaminated as outlined in Section 3.4 of this procedure. • Wash with tap water and detergent, using a brush if necessary, to remove particulate matter and surface films. Steam cleaning (high pressure hot water with detergent) may be necessary to remove matter that is difficult to remove with the brush. Drilling equipment that is steam cleaned should be placed on racks or saw horses at least two feet above the floor of the decontamination pad. Hollow-stem augers, drill rods, etc., that are hollow or have holes that transmit water or drilling fluids, should be cleaned on the inside with vigorous brushing. • Rinse thoroughly with tap water. • Remove from the decontamination pad and cover with clean, unused plastic if not used immediately. If stored overnight, the plastic should be secured to ensure that it stays in place. 3.9.5 Field Decontamination Procedure for Direct Push Technology (DPT) Equipment • Certain specific procedures for the decontamination of DPT tools are described in the various sampling procedures, but the following general guidelines apply: • Prior to return to the Field Equipment Center, all threaded tool joints should be broken apart and the equipment cleaned per the provisions of Section 2.5, Sample Collection Equipment Contaminated with Environmental Media of this procedure. • Equipment that contacts the sample media and is cleaned in the field for reuse should be cleaned per the provisions of Section 3.4, Sampling Equipment used for the Collection of Trace Organic and Inorganic Compounds of this procedure. This would include piston sampler points and shoes, screen point sampler screens and sheaths, and the drive rods when used for groundwater sampling. • Equipment that does not directly contact the sample media and is cleaned in the field for reuse can generally be cleaned per the provisions of Section 3.7.4, Field Decontamination Procedure for Drilling Equipment of this procedure. • Stainless steel SP15/16 well screens require special care as the narrow slots are difficult to clean under even controlled circumstances and galvanic corrosion can release chrome from the screen surface. As soon as possible after retrieval, the screen slots should be sprayed from the outside to break loose as much material as possible before it can dry in place. To prevent galvanic corrosion, the screens must be segregated from the sampler sheaths, drive rods, and other carbon steel during return transport from the field. Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 13 of 15 3.10 Rental Pumps Completing a groundwater sampling project may require the use of rental pumps. Rental pumps are acceptable where they are of suitable stainless steel and Teflon® construction. These pumps should be cleaned prior to use using the procedures specified herein and a rinse-blank collected prior to use. 4 References LSASD Operating Procedure for Management of Investigation Derived Waste, LSASDPROC-202, Most Recent Version LSASD Operating Procedure for Equipment Cleaning and Decontamination at the FEC, LSASDPROC- 206, Most Recent Version US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD, Athens, GA, Most Recent Version Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 14 of 15 Revision History The top row of this table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Document Control Coordinator on the LSASD local area network (LAN). History Effective Date LSASDPROC-205-R4, Field Equipment Cleaning and Decontamination, replaces SESDPROC-205-R3 General: Updated format, Division and Branch names and naming conventions post agency re-alignment. Section 3.1: Added note that PFAS sampling equipment will not be cleaned in the field. Clarified in Section 3.9 that LSASD does not performing drilling activities. June 22, 2020 SESDPROC-205-R3, Field Equipment Cleaning and Decontamination, replaces SESDPROC-205-R2. Cover Page: The author was changed to Brian Striggow. LSASD’s reorganization was reflected in the authorization section by making John Deatrick the Chief of the Field Services Branch. The FQM was changed from Bobby Lewis to Hunter Johnson. Revision History: Changes were made to reflect the current practice of only including the most recent changes in the revision history. General: Corrected any typographical, grammatical and/or editorial errors. Section 1.4: Differentiate between Liquinox® and Luminox® detergents. Section 3.4: Restore solvent rinse as alternative cleaning method. Section 3.7: Added section on cleaning of 12 Volt electric submersible pumps. Section 3.8: Added section on cleaning of bladder pumps. Section 3.9: Added language on cleaning and transport of SP15/16 screens Section 3.10: Added section on cleaning of rental pumps December 18, 2015 SESDPROC-205-R2, Field Equipment Cleaning and Decontamination, replaces SESDPROC-205-R1. December 20, 2011 SESDPROC-205-R1, Field Equipment Cleaning and Decontamination, replaces SESDPROC-205-R0. November 1, 2007 Uncontrolled When Printed LSASDPROC-205-R4 Field Equipment Cleaning and Decontamination Effective Date: June 22, 2020 Page 15 of 15 SESDPROC-205-R0, Field Equipment Cleaning and Decontamination, Original Issue February 05, 2007 Uncontrolled When Printed APPENDIX E SAMPLE HANDLING, PACKING, AND SHIPPING PROCEDURES LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 1 of 7 Purpose Regulations for packing, marking, labeling, and shipping of dangerous goods by air transport are promulgated by Department of Transportation under 49 CFR, Subchapter C, Hazardous Materials Regulations, and the International Air Transport Authority (IATA), which is equivalent to United Nations International Civil Aviation Organization (UN/ICAO). Transportation of hazardous materials (dangerous goods) by EPA personnel is covered by EPA Order 1000. This document describes general and specific procedures, methods and considerations to be used and observed by LSASD field investigators when packing, marking, labeling and shipping environmental and waste samples to ensure that all shipments are in compliance with the above regulations and guidance. Scope/Application The procedures contained in this document are to be used by field personnel when packing, marking, labeling, and shipping environmental samples and dangerous goods by air transport. Samples collected during field investigations or in response to a hazardous materials incident must be classified prior to shipment, as either environmental or hazardous materials (dangerous goods) samples. In general, environmental samples include drinking water, most groundwater and ambient surface water, soil, sediment, treated municipal and industrial wastewater effluent, biological specimens, or any samples not expected to be contaminated with high levels of hazardous materials. Samples collected from process wastewater streams, drums, bulk storage tanks, soil, sediment, or water samples from areas suspected of being highly contaminated may require shipment as dangerous goods. Government employees transporting samples or hazardous materials (i.e., preservatives or waste samples) in government vehicles are not subject to the requirements of this section in accordance with 49 CFR 171.1(d)(5). EPA contractors, however, are not covered by this exemption and may not transport these materials without full compliance with 49 CFR. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Region 4 U.S. Environmental Protection Agency Laboratory Services and Applied Science Division Athens, Georgia Operating Procedure Title: Packing, Marking, Labeling and Shipping of Environmental and Waste Samples ID: LSASDPROC-209-R4 Issuing Authority: LSASD Field Branch Chief Effective Date: February 23, 2020 Review Due Date: February 23, 2024 Uncontrolled When Printed LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 2 of 7 TABLE OF CONTENTS Purpose ................................................................................................................................ 1 Scope/Application ............................................................................................................... 1 1.1 Documentation/Verification ...................................................................................... 3 1.2 General Precautions................................................................................................... 3 1.2.1 Safety.......................................................................................................................... 3 2 Shipment of Dangerous Goods ................................................................................... 3 3 Shipment of Environmental Samples ......................................................................... 3 4 References................................................................................................................... 5 5 Revision History ......................................................................................................... 6 Uncontrolled When Printed LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 3 of 7 1 General Information 1.1 Documentation/Verification This procedure was prepared by persons deemed technically competent by LSASD management, based on their knowledge, skills and abilities and have been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the LSASD local area network (LAN). The Document Control Coordinator (DCC) is responsible for ensuring the most recent version of the procedure is placed on the LAN and for maintaining records of review conducted prior to its issuance. 1.2 General Precautions 1.2.1 Safety Proper safety precautions must be observed when packing, marking, labeling, and shipping environmental or waste samples. Refer to the LSASD Safety, Health and Environmental Management Program (SHEMP) Procedures and Policy Manual and any pertinent site-specific Health and Safety Plans (HASPs) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. 2 Shipment of Dangerous Goods 2.1 The project leader is responsible for determining if samples collected during a specific field investigation meet the definitions for dangerous goods. If a sample is collected of a material that is listed in the Dangerous Goods List, Section 4.2, IATA, then that sample must be identified, packaged, marked, labeled, and shipped according to the instructions given for that material. If the composition of the collected sample(s) is unknown, and the project leader knows or suspects that it is a regulated material (dangerous goods), the sample may not be offered for air transport. If the composition and properties of the waste sample or highly contaminated soil, sediment, or water sample are unknown, or only partially known, the sample may not be offered for air transport. In addition, the shipment of pre-preserved sample containers or bottles of preservatives (e.g., NaOH pellets, HCL, etc.) which are designated as dangerous goods by IATA is regulated. Shipment of nitric acid is strictly regulated. Consult the IATA Dangerous Goods Regulations for guidance. Dangerous goods must not be offered for air transport by any personnel except LSASD’s dangerous goods shipment designee or other personnel trained and certified by IATA in dangerous goods shipment. 3 Shipment of Environmental Samples Uncontrolled When Printed LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 4 of 7 3.1 Guidance for the shipment of environmental laboratory samples by personnel is provided in a memorandum dated March 6, 1981, subject "Final National Guidance Package for Compliance with Department of Transportation Regulations in the Shipment of Laboratory Samples". By this memorandum, the shipment of the following unpreserved samples is not regulated: 3.1.1 Drinking water 3.1.2 Treated effluent 3.1.3 Biological specimens 3.1.4 Sediment 3.1.5 Water treatment plant sludge 3.1.6 POTW sludge 3.2 In addition, the shipment of the following preserved samples is not regulated, provided the amount of preservative used does not exceed the amounts found in 40 CFR 136.3 or the USEPA Region 4 Analytical Support Branch Laboratory Operations and Quality Assurance Manual (ASBLOQAM), Most Recent Version. This provision is also discussed in correspondence between DOT and EPA (Department of Transportation, Letter from Edward T. Mazzullo, Director, Office of Hazardous Materials Standards, to Henry L. Longest II, Acting Assistant Administrator, USEPA, Ref No.: 02-0093, February 13, 2003). It is the shippers' (individual signing the air waybill) responsibility to ensure that proper amounts of preservative are used: 3.2.1 Drinking water 3.2.2 Ambient water 3.2.3 Treated effluent 3.2.4 Biological specimens 3.2.5 Sediment 3.2.6 Wastewater treatment plant sludge 3.2.7 Water treatment plant sludge 3.3 Samples determined by the project leader to be in these categories are to be shipped using the following protocol, developed jointly between USEPA, OSHA, and DOT. This procedure is documented in the "Final National Guidance Package for Compliance with Department of Transportation Regulations in the Shipment of Environmental Laboratory Samples." 3.4 Untreated wastewater and sludge from Publicly Owned Treatment Works (POTWs) are considered to be "diagnostic specimens" (not environmental laboratory samples). However, because they are not considered to be etiologic agents (infectious) they are not restricted and may be shipped using the procedures outlined below. Uncontrolled When Printed LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 5 of 7 3.5 Environmental samples should be packed prior to shipment by air using the following procedures: 3.5.1 Allow sufficient headspace (ullage) in all bottles (except VOA containers with a septum seal) to compensate for any pressure and temperature changes (approximately 10 percent of the volume of the container). 3.5.2 Ensure that the lids on all bottles are tight (will not leak). 3.5.3 Place bottles in separate and appropriately sized polyethylene bags and seal the bags. If available, the use of Whirl-Pak bags is preferable, if unavailable seal regular bags with tape (plastic electrical tape). 3.5.4 Select a sturdy cooler in good repair. Secure and tape the drain plug with fiber or duct tape inside and outside. Line the cooler with a large heavy duty plastic bag. 3.5.5 Place cushioning/absorbent material in the bottom of the cooler and then place the containers in the cooler with sufficient space to allow for the addition of cushioning between the containers. 3.5.6 .If required by the method for preservation, put "blue ice" (or ice that has been "double bagged" in heavy duty polyethylene bags and properly sealed) on top of and/or between the containers. Fill all remaining space between the containers with absorbent material. 3.5.7. If the samples are preserved with ice, include a temperature blank for the laboratory to verify that the samples are received at the appropriate temperature. 3.5.8 Securely fasten the top of the large garbage bag with tape (preferably plastic electrical tape). 3.5.9 Place the Chain-of-Custody Record or the CLP Traffic Report Form (if applicable) into a plastic bag and tape the bag to the inner side of the cooler lid. 3.5.10 Close the cooler and securely tape (preferably with fiber tape) the top of the cooler shut. Chain-of-custody seals should be affixed to the top and sides of the cooler within the securing tape so that the cooler cannot be opened without breaking the seal. 4 References International Air Transport Authority (IATA). Dangerous Goods Regulations, Most Recent Version. LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 6 of 7 Title 40 Code of Federal Regulations (CFR), Pt. 136.3, Identification of Test Procedures, July 1, 2001. See Table II, Footnote 3. Title 49 CFR, Pt. 171.1(d)(5), Applicability of Hazardous Materials Regulations (HMR) to Persons and Functions. United States Department of Transportation (US DOT). 2003. Letter from Edward T. Mazzullo, Director, Office of Hazardous Materials Standards, to Henry L. Longest II, Acting Assistant Administrator, USEPA, Ref No. 02-0093, February 13, 2003. US Environmental Protection Agency (US EPA) Order 1000.18, February 16, 1979. US EPA. 1981. "Final Regulation Package for Compliance with DOT Regulations in the Shipment of Environmental Laboratory Samples," Memo from David Weitzman, Work Group Chairman, Office of Occupational Health and Safety (PM-273), April 13, 1981. US EPA. 2001. Environmental Investigations Standard Operating Procedures and Quality Assurance Manual. Region 4 Science and Ecosystem Support Division (LSASD), Athens, GA. US EPA. Analytical Support Branch Laboratory Operations and Quality Assurance Manual. Region 4 LSASD, Athens, GA, Most Recent Version. US EPA. Safety, Health and Environmental Management Program Procedures and Policy Manual. Region 4 LSASD Athens, GA, Most Recent Version. 5 Revision History This table shows the most recent changes to this controlled document. For previous revision history information, archived versions of this document are maintained by the LSASD Quality Assurance Coordinator on the LSASD local area network (LAN). History Effective Date LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping of Environmental and Waste Samples, replaces LSASDPROC-209-R3 Reformatted document to Divisional Format February 23, 2020 LSASDPROC-209-R3, Packing, Marking, Labeling and Shipping of Environmental and Waste Samples, replaces LSASDPROC-209-R2. February 4, 2015 Uncontrolled When Printed LSASDPROC-209-R4 Packing, Marking, Labeling and Shipping Waste Effective Date: February 23, 2020 Page 7 of 7 Cover Page: Changes made to reflect reorganization of LSASD from two field branches to one: John Deatrick listed as the Chief, Field Services Branch. The FQM was changed from Liza Montalvo to Hunter Johnson. Revision History: Changes were made to reflect the current practice of only including the most recent changes in the revision history. LSASDPROC-209-R2, Packing, Marking, Labeling and Shipping of Environmental and Waste Samples, replaces LSASDPROC-209-R1. April 20, 2011 LSASDPROC-209-R1, Packing, Marking, Labeling and Shipping of Environmental and Waste Samples, replaces LSASDPROC-209-R0. November 1, 2007 LSASDPROC-209-R0, Packing, Marking, Labeling and Shipping of Environmental and Waste Samples, Original Issue February 05, 2007 Uncontrolled When Printed APPENDIX F EXAMPLE FIELD FORMS TIME FLOW RATE (ml/ min) TURBIDITY (NTU) pH (S.U.) Cl (mg/L) ORP (mV) Diss. Oxygen (ppm) SP. COND. (µS/cm)Color TEMP. (°C) TDS (ppm) WATER LEVEL (ft btoc) DRAW- DOWN (ft) MAX ALLOW. DD (ft) Notes: Deviations from SAP: TDS (ppm):Spec. Cond. (µS/cm): Color/Appearance: Odor: Pump Depth (ft btoc): Diss. Oxygen (ppm): FIELD MEASUREMENTS AT TIME OF SAMPLE ORP (mV): Date: Time of Purge Initiation:Static Water Level (ft btoc): Time: Turbidity (NTU): Volume Removed (gal): Water Level (ft btoc): Well #: Water Level after Pump Installation (ft btoc): pH (S.U.): Cl (mg/L): Other Field Measurements: Depth to Top of Screen (ft btoc): Well Diameter (in.): Date/Time of Pump Installation: permanent  temporary Pump Type: LOW FLOW SAMPLING DATA SHEET Site: Personnel: Project No.: Date: Total Depth (ft btoc): Page 1 of 1 phone 912.354.7858 fax 912.352.0165 Regulatory Program:Eurofins Environment Testing America COC No: TALS Project #: Sampler: For Lab Use Only: Walk-in Client: Lab Sampling: Job / SDG No.: Sample Date Sample Time Sample Type (C=Comp, G=Grab)Matrix # of Cont. Custody Seals Intact: Cooler Temp. (oC): Obs'd:_________ Corr'd:__________ Therm ID No.:____________ Company: Date/Time: Date/Time:Company: Are any samples from a listed EPA Hazardous Waste? Please List any EPA Waste Codes for the sample in the Comments Section if the lab is to dispose of the sample. Sample Disposal ( A fee may be assessed if samples are retained longer than 1 month)Possible Hazard Identification: Sample Identification Site: (xxx) xxx-xxxx Phone Relinquished by: Date/Time: Date/Time: Date/Time: Special Instructions/QC Requirements & Comments: Relinquished by: Custody Seal No.: Preservation Used: 1= Ice, 2= HCl; 3= H2SO4; 4=HNO3; 5=NaOH; 6= Other _____________ Relinquished by: Company: Company: Company: Date/Time: Received by: Received by: Received in Laboratory by: Company: Client Contact Your Company Name here Email: Eurofins Savannah 5102 LaRoche Avenue Savannah, GA 31404-6019 (xxx) xxx-xxxx FAX Date:_______ of ______ COCs Chain of Custody Record Site Contact:Perform MS / MSD ( Y / N )Project Manager: Tel/Fax: Analysis Turnaround Time Carrier:Lab Contact: Sample Specific Notes: City/State/Zip Filtered Sample ( Y / N )P O # Project Name: Address TAT if different from Below __________ DW NPDES RCRA Other: 2 weeks 1 week 2 days 1 day FlammableNon-Hazard Skin Irritant Poison B Unknown Return to Client Disposal by Lab Archive for___________ Months NoYes CALENDAR DAYS WORKING DAYS