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HomeMy WebLinkAbout6004_DukeMcGuire_LF1_GWAssessmentWorkPlan_FID1823030_20231204%> DUKE ENERGY December 4, 2023 North Carolina Department of Environmental Quality Division of Waste Management Solid Waste Section 2090 U.S. Highway 70 Swannanoa, NC 28778 Attn: Ms. Sarah Moutos (submitted electronically) Re: Groundwater Assessment Work Plan Duke Energy Carolinas, LLC McGuire Nuclear Station Landfill No. 1 (Unlined), Permit 6004-INDUS Mecklenburg County, North Carolina Dear Ms. Moutos: Duke Energy McGuire Nuclear Station 12700 Hagers Ferry Road Huntersville, NC 28078 For approval, the enclosed Groundwater Assessment Work Plan is transmitted herein by Duke Energy Carolinas, LLC (Duke Energy) for the McGuire Landfill No. 1 (Unlined) (landfill, PN 6004- INDUS), located near Huntersville in Mecklenburg County, North Carolina. This Groundwater Assessment Work Plan presents a brief site history, current conceptual site model information, and describes the proposed scope of work to further assess the cause, significance, and extent of groundwater impacts in pursuant to 15 NCAC 02L .0106(d) at the subject site. This Work Plan was developed in response to a 25 May 2023 request for assessment from the North Carolina Department of Environmental Quality, Division of Waste Management in a letter to Duke Energy. If you need additional information regarding this submittal, please contact Ashley Healy at Ashley.Healy(a-)-duke-energy.com or (717) 982-0986. Sincer Brent Bare Duke Energy McGuire Nuclear Station Plant Manager www.duke-energy.com Page 1 of 1 '%ERICH www.haleyaldrich.com GROUNDWATER ASSESSMENT WORK PLAN DUKE ENERGY CAROLINAS, LLC, MCGUIRE NUCLEAR STATION INDUSTRIAL LANDFILL NO. 1 (NCDEQ SOLID WASTE PERMIT NO. 6004-INDUS-1981) HUNTERSVILLE, NORTH CAROLINA by Haley & Aldrich of North Carolina, P.C. Greenville, South Carolina for Duke Energy Carolinas, LLC McGuire Nuclear Station Mecklenburg County, North Carolina File No. 0209037 December 2023 '%ERICH 1 December 2023 File No. 0209037 Duke Energy Carolinas, LLC 526 South Church Street I Mail Code EC12J Charlotte, North Carolina 28202 HALEY & ALDRICH 400 Augusta Street Suite 100 Greenville, SC 29601 864.214.8750 Attention: Ashley L. Healy, P.G. Senior Environmental Specialist, Waste and Groundwater Programs Subject: Groundwater Assessment Work Plan Duke Energy Carolinas, LLC McGuire Nuclear Station Industrial Landfill No. 1 (NCDEQSolid Waste Permit No. 6004-INDUS-1981) Huntersville, North Carolina Dear Ms. Healy: Haley & Aldrich of North Carolina, P.C.1(Haley & Aldrich) is pleased to submit this Groundwater Assessment Work Plan (Work Plan) for the Duke Energy Carolinas, LLC (Duke Energy), McGuire, Landfill No. 1(Unlined). This Work Plan presents a brief site history, current conceptual site model information, and describes the proposed scope of work to further assess groundwater impacts at the subject site. This Work Plan was developed in response to a 25 May 2023 request for assessment from the North Carolina Department of Environmental Quality, Division of Waste Management in a letter to Duke Energy. Sincerely yours, HALEY & ALDRICH OF NORTH CAROLINA, P.C. License Numbers C-5077 and C-610 Mark Higgins, Ph.D. Senior Technical Specialist I Geologist Enclosures Christopher Turner, L.G. (NC License #2396) Senior Technical Expert I Geologist https://haleyaldrich.sharepoint.com/sites/Duke-0209037.McGuireNC/Shared Documents/0209037.McGuire NC/000 - LF 1 BR GW/001 - Work Plan/2023- 1201 Duke McGuire Work Plan-F.docx 1 License Numbers C-5077 and C-610 www.haleyaldrich.com "kDRICH SIGNATURE PAGE FOR HALEY & ALDRICH 400 AUGUSTA STREET SUITE 100 GREENVILLE, SC 29601 864.214.8750 GROUNDWATER ASSESSMENT WORK PLAN DUKE ENERGY CAROLINAS, LLC MCGUIRE NUCLEAR STATION INDUSTRIAL LANDFILL NO. 1 (NCDEQSOLID WASTE PERMIT NO. 6004-INDUS-1981) HUNTERSVILLE, NORTH CAROLINA PREPARED FOR DUKE ENERGY CAROLINAS, LLC MCGUIRE NUCLEAR STATION MECKLENBURG COUNTY, NORTH CAROLINA PREPARED BY: V (� ,hMNrrnVA C'4 Casey M. ortela, L.G. (NC License #2525) _; CENSF�O�''s; Assistant Project Manager I Geologist S O Z Haley &Aldrich of North Carolina, P.C. = D 2FAL cn % > 525 REVIEWED AND APPROVED BY: ••.,,���R„ENpO ���,, ark Higgins, A.D. Senior Technical Specialist I Geologist Haley & Aldrich of North Carolina, P.C. Christopher Turner, L.G. (NC License #2396) Senior Technical Expert I Geologist Haley & Aldrich of North Carolina, P.C. www.haleyaldrich.com Table of Contents Page List of Tables ii List of Figures ii List of Appendices ii 1. Introduction 1 1.1 OBJECTIVES 1 2. Site Description and History 2 2.1 SITE DESCRIPTION 2 2.2 SITE HISTORY 2 2.3 CURRENT CONCEPTUAL SITE MODEL 2 2.3.1 Geologic and Hydrogeologic Setting 2 2.3.2 Distribution of Impacts 3 2.3.3 Data Gaps 4 3. Scope of Work 5 3.1 TECHNICAL APPROACH 5 3.2 FIELD PREPARATION 6 3.2.1 Health and Safety planning 6 3.2.2 Permit 6 3.3 FIELD PROCEDURES 6 3.3.1 Utility Locate and Soft Digging 6 3.3.2 Borehole Drilling 6 3.3.3 Soil Characterization 7 3.3.4 Borehole Geophysics 7 3.3.5 Packer Testing 7 3.3.6 Well Installation 7 3.3.7 Well Development 8 3.3.8 Surveying 8 3.3.9 Groundwater Sampling 8 3.3.10 Slug Testing 9 3.3.11 Transducer Study 9 3.3.12 Investigation Derived Waste Management 10 3.3.13 Quality Assurance/Quality Control Procedures 10 4. Reporting and Schedule 11 4.1 REPORTING 11 4.2 SCHEDULE 11 References 12 '%DRICH List of Tables Table No. Title Proposed Scope of Work Summary Table List of Figures Figure No. Title Site Location Map 2 Proposed Well Location Map List of Appendices Appendix Title A Groundwater Contour Maps January 2023 (S&ME, March 2023) NCDEQ Solid Waste Section Guidelines for Groundwater, Soil and Surface Water Sampling C Geoprobe° Pneumatic Slug Test Kit Installation and Operation Instructions Instructional Bulletin No. MK3195 %DRICH 1. Introduction Duke Energy Carolinas, LLC (Duke Energy) retained Haley & Aldrich of North Carolina, P.C. (Haley & Aldrich) to prepare this Groundwater Assessment Work Plan (Work Plan) for the Duke Energy Carolinas, McGuire, Landfill No. 1 (Unlined)', Permit No. 6004-INDUS-1981 (hereafter, landfill and/or Site), located near Huntersville, North Carolina (see Figure 1). This Work Plan describes a supplemental assessment of impacts to overburden and bedrock groundwater quality within the landfill compliance boundary (Figure 2). The scope of groundwater assessment activities described in this Work Plan address requirements of an assessment per 15A North Carolina Administrative Code (NCAC) subchapter 02L .0106(d) and data gaps identified by the North Carolina Department of Environmental Quality (NCDEQ), Division of Waste Management in the letter to Duke Energy dated 25 May 2023. 1.1 OBJECTIVES The Work Plan objectives build upon previous site characterization and groundwater monitoring work completed at the Site and consist of the following: • Further assess the nature and extent (horizontal and vertical) of landfill related impacts from volatile organic compounds (VOCs) to groundwater at the Site. • Refine the conceptual site model to further assess where the top of competent bedrock is encountered across the Site and to better define the hydraulic properties of each hydrogeologic unit (i.e., saprolite, transition zone/partially weathered rock, competent bedrock). • Collect sufficient data to evaluate the likelihood that groundwater VOC concentrations will increase to a level greater than the 15A NCAC 02L .0202 water quality standards (02L Standards) at the 250 feet compliance boundary. • Recommend a plan for continued monitoring and effectiveness reporting should VOC concentrations greater than the 02L Standards be predicted at or beyond the compliance boundary. The Site received a Permit to Construct an amended final cover system for the landfill, consisting of a geosynthetic cap, which is intended to alter the facility design to prevent further release of constituent migration to the underlying groundwater system. The landfill amended final cover system construction is expected to be completed in Spring 2024. 'In response to the North Carolina Division of Public Health, Radiation Protection Section, November 17, 2006, letter to Duke Energy, LLC, Duke Energy offered to indicate the Landfill No. 1 as (Unlined) in reports. %DRICH 2. Site Description and History 2.1 SITE DESCRIPTION The landfill is located south of the Duke Energy McGuire Nuclear Station and approximately 0.9 miles south of NC-73 in Mecklenburg County, North Carolina (Figure 1). It is part of a 488-acre parcel of land owned by Duke Energy (Mecklenburg County Parcel ID # 01315102). The Catawba River is located west of the landfill with Cashion Road bounding the eastern side. 2.2 SITE HISTORY Operation of the landfill began in 1972, with a total of 10 trenches approved by NCDEQ Solid Waste Section between 1972 and 1986. It was assigned permit #60-04 in 1981. It ceased operations and was closed with a soil/vegetative cover in 1993. During operation, the landfill was permitted to accept construction material and other wastes including paper, cans, lunch box scraps, and fish waste. Disposal was also permitted on a case -by -case basis for oil absorbent materials, carbon granules, sludge, borax, diatomaceous earth, and ion exchange resins (Wood, 2021). Groundwater monitoring was initiated in 1989 with the installation of monitoring wells. A groundwater monitoring sampling and analysis plan (SAP) was approved in 1989 and subsequently revised in 1996, 1997, 2001, and 2019. Approximately 20 monitoring wells have been installed at the Site, including five bedrock monitoring wells (identified by "BR" in the well ID) installed in late 2020. The monitoring well network is shown on Figure 2. Groundwater monitoring events are performed on a semiannual basis (January and July). 2.3 CURRENT CONCEPTUAL SITE MODEL This section presents a summary of the Site geologic and hydrogeologic conditions, along with a description of the distribution of landfill -related VOCs in groundwater. Data gaps that have been identified by NCDEQ are listed at the end of this section. 2.3.1 Geologic and Hydrogeologic Setting The landfill is located in the Piedmont physiographic region. Topographically, the Piedmont is characterized by gently undulating hills and shallow stream valleys. Competent bedrock in this region is overlain by a layer of deeply weathered but otherwise in -place bedrock regolith. This chemically weathered bedrock is known as "saprolite," and is conventionally subdivided into a fully weathered saprolite zone, and a "transition zone" containing partially weathered rock (PWR). The level of decomposition of the parent rock encountered in the PWR is understood to vary substantially at the Site scale. Generally, the average hydraulic conductivity in PWR is greater than the overlying saprolite and the underlying competent fractured bedrock. Where present and continuous, the PWR may serve as a preferential pathway for groundwater flow. Bedrock at the Site has been logged as predominantly diorite, with some other distinct intrusive lithologies (including granodiorite, granite, gabbro, and diabase) encountered in the southern portion of the Site. Unconsolidated materials surrounding the solid waste area have been logged as fill (sandy silt, clay, and gravel) at a thickness of up to 11 feet beneath a thin layer of topsoil, underlain by micaceous %DRICH silt with varying percentages of fine-grained sand. This grades into silty fine- to medium -grained sand saprolite (Wood, 2021). Shallow groundwater at the Site has been encountered at depths ranging from approximately 20 to 65 feet below ground surface (bgs). Groundwater has been interpreted to flow primarily to the northwest (Appendix A). Existing monitoring wells installed at the Site target three hydrogeologic intervals: Water Table Zone: Consists of the upper portion of the unconfined aquifer, near the water table. Wells within this zone are screened in saprolite and are 75 feet bgs or less in depth. • Basal Saprolite/Transition Zone: Encompasses the base of the saprolite and the PWR above competent bedrock. The saprolite/PWR contact was typically observed between 73.5 and 93.5 feet bgs (Wood, 2021). Wells screened within this zone are identified with the designation "D" or "DR" (e.g., well MW-1D) and generally fall within the approximate saprolite/PWR contact depth range except for well MW-12D, where the transition zone was identified at a shallower depth and the well is screened at 56 to 66 feet bgs. Bedrock zone: Slightly weathered to competent bedrock where groundwater flow is expected to occur in fractures. Wells within this zone are identified with the "BR" or "BRR" designation and are screened between 123 and 202 feet bgs. The interpreted direction of groundwater flow at the Site is predominantly to the northwest, as shown on the shallow groundwater contour map interpolated from January 2023 water level measurements (Appendix A). 2.3.2 Distribution of Impacts VOCs (benzene, methylene chloride, tetrachloroethene [PCE], trichloroethene [TCE], and vinyl chloride [VC]) have been detected at concentrations greater than the 02L Standards in Site monitoring wells. Detected concentrations greater than 02L Standards have been limited to five wells downgradient (north and northwest) of the landfill (Figure 2): Wells MW-4/MW-4D/MW-4BR — This well cluster is located closest to the limits of waste and generally exhibits the highest concentrations of PCE, TCE, and VC in the water table zone or basal saprolite/transition zone at the Site. Methylene chloride is consistently detected at concentrations greater than the 02L Standards in the basal saprolite/transition zone and in the bedrock well. Benzene was also previously detected above the 02L Standards in the transition zone well between 2017 and 2021 and in the bedrock well in one sampling event in November 2020. • Well MW-3BR—This bedrock well is located approximately 60 feet horizontally beyond the limits of waste. Although not located at the review boundary due to access limitation during installation, this location is interpreted as a review boundary monitoring well. It exhibits the highest methylene chloride concentrations in Site monitoring wells. Benzene was also detected at a concentration greater than the 02L Standards in this well in one sampling event in July 2022 and PCE was detected above the 02L Standards in this well in two sampling events (July 2021 and July 2022). • Well MW-4R —This water table zone well is located at the review boundary and has exhibited VOC concentrations greater than the 02L Standards. The elevated VOC detected in this well was %DRICH PCE, which was detected in January 2023 at an estimated concentration of 0.8 J micrograms per liter (µg/L), below the laboratory reporting limit, but above the 02L Standards of 0.7 µg /L. Unlike the other detected VOCs, which have exhibited the highest concentrations in water table zone wells or basal saprolite/transition zone wells, methylene chloride tends to exhibit greater concentrations in bedrock wells. The only other VOCs detected above 02L Standards in bedrock wells have been benzene historically in wells MW-3BR and MW-4BR and PCE in well MW-3BR. Non-VOC analytes have also been detected at concentrations greater than the 02L Standards in Site monitoring wells. Detected concentrations greater than 02L Standards are limited to two wells downgradient (north and west) of the landfill (Figure 2): • Sulfate has been consistently detected at concentrations above the 02L Standards in well MW-4BRR, and is attributed to grout intrusion during well construction. • Chromium was detected greater than the 02L Standards in well MW-4BRR in one sampling event in January 2021. • Gross alpha analytes were also previously detected above the 02L Standards in the bedrock well MW-4BRR in one sampling event in July 2021. • Lead was detected greater than the 02L Standards at review boundary well MW-3 for the first time during the January 2023 sampling event. 2.3.3 Data Gaps The following data gaps were identified as needing further assessment by NCDEQ in its request for an assessment letter to Duke Energy dated 25 May 2023: • Lack of subsurface data between well clusters MW-4R and MW-11 on the southwestern edge of the review boundary. Insufficient delineation of the vertical extent of contamination, in particular at wells MW-313R, MW-413R, and MW-4BRR. 4 %DRICH 3. Scope of Work This section describes the planned scope of work for additional groundwater assessment, developed to address requirements of 15A NCAC 02L .0106(d) and the data gaps identified above. Additional details on planned monitoring well construction, hydraulic testing, sampling methods, analyses, and operating procedures are described near the end of this section. 3.1 TECHNICAL APPROACH Up to 11 monitoring wells will be installed in a clustered geometry at five proposed locations, shown on Figure 2. Each well cluster will consist of 2-inch diameter polyvinyl chloride (PVC) monitoring wells installed in separate borings and screened at the shallow water table, in the transition zone, and in the competent bedrock. Approximate screen depths, targeted hydrogeologic unit, and data collection planned for each proposed well are summarized in Table 1. The rationale and objectives of the proposed locations are summarized below. Two new well clusters are proposed near the 250 feet compliance boundary: • Wells MW-14/MW-14D/MW-14BR — to confirm presence or absence of constituents in groundwater, particularly impacts to bedrock groundwater, beyond the review boundary, approximately downgradient of well MW-3BR. Wells MW-15/MW-15D/MW-15BR — to confirm presence or absence of constituents in groundwater, particularly impacts to bedrock groundwater, beyond the review boundary, approximately downgradient of wells MW-4BR and MW-4BRR. The MW-15 cluster will be installed approximately downgradient of well MW-4BRR to verify elevated pH and sulfate in that well are related to grout misplacement during well construction, not migration of impacted groundwater from the landfill. One new well cluster is proposed at the review boundary: • Wells MW-16/MW-16D/MW-16BR — to address the data gap (i.e., lack of groundwater monitoring points) between the wells MW-11 and MW-4R. Two new monitoring wells are proposed at existing well clusters: • Well MW-13 — to add an interval screened at the shallow water table. • Well MW-3BRR — screened in the competent bedrock, at a greater depth than well MW-3BR to improve vertical delineation of constituents in bedrock groundwater at the review boundary. A series of proposed tests, summarized in Table 1, will be performed in the well borings to aid in screen depth selection and to better define the hydraulic properties of each hydrogeologic unit encountered at the Site. Resulting data will be used to refine the conceptual site model and improve the understanding of groundwater flow and contaminant transport at the Site. %DRICH 3.2 FIELD PREPARATION 3.2.1 Health and Safety planning Haley & Aldrich will prepare a Site -specific Health and Safety Plan (HASP) to identify and eliminate or mitigate field hazards specific to the planned investigation activities. The HASP will be reviewed by the field team in advance of fieldwork. In addition, a meeting will be held prior to the start of fieldwork to review project scope, schedule, potential hazards, and strategies to mitigate those hazards. 3.2.2 Permit Haley & Aldrich, on behalf of Duke Energy and prior to the start of fieldwork, will apply for a Mecklenburg County Subsurface Investigation Permit as required under Chapter VI of the Mecklenburg County Groundwater Well Regulations. 3.3 FIELD PROCEDURES Field activities will be completed in accordance with the NCDEQ Solid Waste Section Guidelines for Groundwater, Soil, and Surface Water Sampling (Appendix B) (NCDEQ SWS Guidelines) and where applicable the McGuire Landfill No. 1 Sampling and Analysis Plan (SAP) dated 13 May 2022. Field procedures are outlined in the sections below. 3.3.1 Utility Locate and Soft Digging Prior to the start of the field investigation Haley & Aldrich will contact North Carolina 811 (utility notification center). Haley & Aldrich will engage with a qualified subcontractor to conduct a private utility locate use electromagnetic and ground -penetrating radar tools in a 25-foot-diameter area surrounding each planned drilling location and use soft dig methods (air jet and vacuum) to confirm the absence of utilities to a depth of 5 feet at each location. The width of soft dig excavations will be equal or greater than the width of the planned boring at each location. 3.3.2 Borehole Drilling Well drilling and installation will be performed by a North Carolina -licensed contractor using hollow stem auger methods for shallow soil and saprolite (to an assumed depth up to 100 feet). Bedrock wells will be advanced through shallow soils and saprolite using a larger diameter hollow stem auger to refusal. A rotary bit will be used to advance the boring approximately 5 feet into competent rock where a permanent 6-inch-diameter conductor casing will be grouted into place to isolate the bedrock zone from the overlying groundwater. After allowing a minimum of 24 hours for the grout to cure, the boring will be advanced beyond the bottom of the conductor casing using air hammer methods to the target depth between approximately 155 and 195 feet bgs. Haley & Aldrich will provide technical oversight of all drilling activities by a North Carolina Licensed Geologist. The drilling contractor will decontaminate downhole equipment according to NCDEQ SWS Guidelines between drilling locations. Bedrock boreholes will remain open until borehole geophysics and packer testing are completed. Final well screen intervals will be selected to target hydraulically active fractures identified using the downhole testing results. 6 %DRICH Soil sampling will be conducted at the boring locations by advancing a 2-foot long split spoon sampling device in advance of the auger. Soil recovered from each sample interval will be visually characterized for color, texture, and moisture content. 3.3.3 Soil Characterization Haley and Aldrich will collect one soil sample from each of the four proposed saprolite/water table zone well screen intervals. The samples will be submitted for laboratory analysis of grain -size distribution and total porosity. 3.3.4 Borehole Geophysics Following advancement of bedrock boreholes at each of the four planned bedrock well locations, the drilling rig will demobilize from the Site temporarily. Borehole geophysical logging and heat pulse flow metering (HPFM) will be conducted in each of the four boreholes to characterize the borehole fracture spacing and orientation, rock characteristics, and groundwater flow within the open borehole. Borehole logging methods are specified below in Table 11. Haley & Aldrich will use information from drilling, such as water production rates and return of oxidized rock cuttings, interpreted results from borehole geophysics, and HPFM results to identify likely hydraulically active features in the competent bedrock. One or more intervals in each borehole will be selected as potential targets for well screen installation to be verified with packer testing. Table 11. Proposed Geophysical and Flowmeter Logging in Bedrock Boreholes for Selection of Well Screen Depth Intervals. Geophysical Tests Optical Televiewer (OTV) Single Point Resistance (SPR) Acoustic Televiewer (ATV) Fluid Temperature Acoustic Caliper Fluid Conductivity Natural Gamma Ray Heat Pulse Flow Meter (HPFM): Spontaneous Potential (SP) Under Ambient and Pumping Conditions 3.3.5 Packer Testing Following review of drilling logs, geophysical logs, and HPFM results, hydraulic straddle packer testing will be performed on up to three depth -discrete intervals in each open bedrock borehole as needed to verify the transmissivity of those zones are appropriate for well installation. The packer assembly will isolate an approximately 10-foot vertical interval in the bedrock borehole. Groundwater will be extracted from each isolated interval and the rate of water level recovery measured to confirm which intervals are suitable for monitoring well installation. 3.3.6 Well Installation Monitoring wells will be constructed in accordance with 15A NCAC Subchapter 02C applicable rules. In general, wells will be constructed using 2-inch diameter Schedule 40 PVC pipe and will be screened over a 5- to 10- foot intervals with 0.010-inch machine -slotted PVC screen. The approximate proposed well %DRICH depths and screen intervals are presented in Table 1 and may be modified in the field based on drilling observations and results from geophysics, HPFM, and packer testing. For wells installed in the shallow water table zone and the transition zone, the 2-inch slotted screen riser pipe will be lowered through the center of the hollow stem auger to the bottom of the boring. A filter sand will be used to fill the annular space around the screen and will extend 2 feet above. Approximately 3 feet of bentonite pellets or chips will be emplaced above the sand pack. After allowing ample time for the bentonite to fully hydrate, the remaining annular space will be tremie grouted to the surface. Bedrock monitoring wells will be installed following the completion of the downhole geophysics and hydraulic packer testing. The depth of bedrock monitoring well screen intervals will be selected based on results from downhole testing, where hydraulically active fractures are indicated. In general, the bedrock monitoring well screen interval will target the most transmissive fracture zone in the competent bedrock. Alternatively, if transmissive fractures with similar orientation are observed in multiple bedrock borings at the Site, they will be targeted for the final well screen intervals to develop an understanding of hydraulic gradients along continuous transmissive features. Open bedrock boreholes will be backfilled with bentonite pellets or chips to a depth of approximately 1 foot below the selected screen interval. Bentonite pellets or chips will be used to fill the annular space from the top of the sand pack up to at least 2 feet into the 6-inch outer casing. After allowing ample time for the bentonite to fully hydrate, the remaining annular space will be tremie grouted to the surface. A stickup surface completion will be installed at each well location. A 2 foot by 2 foot concrete pad with protective bollards will be installed around the completed well. 3.3.7 Well Development Each new monitoring well will be developed by pumping with a submersible pump at the maximum rate that can be sustained by the well. If wells are pumped dry, they will be allowed to recover and pumped again a minimum of three times. Development will continue until the turbidity is reduced to 10 nephelometric turbidity units or less and pH and conductivity measurements have stabilized, or until the well has been purged for two hours, whichever comes first. The rate, quantity, and water quality parameters of groundwater removed from each monitoring well during development will be recorded on a field form. 3.3.8 Surveying A subcontracted North Carolina -licensed surveyor will survey the horizontal coordinates and the elevation of ground surface, well pad, and top of casing at each of the new wells following installation. 3.3.9 Groundwater Sampling Haley & Aldrich will collect one round of groundwater samples from each of the 11 planned new monitoring wells. Dedicated bladder pumps will be installed in each new well prior to sampling. A synoptic water level measurement event will be completed before groundwater sampling activities start. The wells will be sampled in accordance with NCDEQ SWS Guidelines (Appendix B) and the SAP %DRICH dated 13 May 2022. Groundwater samples will be collected for laboratory analysis of the following parameters: • barium, calcium, magnesium, potassium, and sodium using U.S. Environmental Protection Agency (USEPA) Solid Waste (SW)-846 Method 6010D; • arsenic, cadmium, chromium, lead, selenium, and silver using USEPA SW-846 Method 602013; • mercury using USEPA SW-846 Method 7470A; • chloride and sulfate using USEPA SW-846 Method 9056A; • alkalinity using USEPA Method 232013; and • VOCs using USEPA SW-846 Methods 8260B and 8260SIM for 1,4-Dioxane. Haley & Aldrich will collect the samples in laboratory -provided containers, store them on ice, and submit the samples under chain -of -custody procedures to Pace Analytical in Huntersville, North Carolina, a North Carolina Division of Water Resources -certified laboratory. 3.3.10 Slug Testing Pneumatic single well response tests ("slug" tests) will be performed in each of the 11 new monitoring wells and eight existing monitoring wells located downgradient of the landfill to estimate the hydraulic conductivities in each of the hydrogeologic units at the Site. Pneumatic slug testing uses compressed air to pressurize the headspace in the well through a manifold attached to the wellhead while monitoring the changes to the static water level with a transducer submerged in the well. After pressurizing the head space and waiting for the water level to re -equilibrate to the increased pressure, a ball valve on the manifold is opened to rapidly release the pressure. This results in a sudden change in hydraulic head, and the response of the water column is captured by the submerged pressure transducer. A detailed standard operating procedure based on ASTM standards is provided in Appendix C. 3.3.11 Transducer Study Datalogging pressure transducers will be installed in 15 existing wells prior to the start of well drilling and development to generate baseline hydrographs and evaluate water level responses to investigation activities. Wells selected for automated water level monitoring are indicated in Table 1. Additional dedicated datalogging pressure transducers will be deployed in the newly installed monitoring wells after each well is completed. The transducers will be sealed (non -vented) and programmed to collect measurements at a frequency not less than once every two hours. Results will be compensated for barometric pressure changes measured using an on -Site barometric pressure transducer installed above the static water level in at least one well at the Site and programmed for the same measurement frequency as the submerged transducers. Prior to installing transducers in existing wells, a synoptic round of water level measurements will be collected from each well to record the static water levels. %DRICH 3.3.12 Investigation Derived Waste Management Solid investigation derived waste (IDW), including soil and rock cuttings, will be transported to the lined McGuire Landfill No. 2 for disposal. Waste personal protective equipment and sampling supplies (e.g., used tubing), will be placed in regular solid waste containers at McGuire Station. Liquid IDW, consisting of drilling fluids, equipment decontamination wash water, and groundwater from well development, purging and sampling activities will be contained at the wellhead or decontamination station as it is generated, then transported to within the waste limits footprint of Landfill No. 1 and discharged to ground surface for infiltration. 3.3.13 Quality Assurance/Quality Control Procedures Quality assurance/quality control samples, including trip blanks, equipment blanks, blind duplicates, and matrix spike/matrix spike duplicate samples will be collected in accordance with the SAP. 10 %DRICH 4. Reporting and Schedule 4.1 REPORTING Haley & Aldrich will prepare an assessment report following completion of field activities and receipt of laboratory analytical results and pressure transducer data. The report will summarize the completed activities, results obtained from the investigation, and provide an interpretation of those results synthesized with historical investigation and groundwater monitoring results. The assessment report will be submitted to NCDEQ. 4.2 SCHEDULE The proposed schedule for completion of the scope of work in this Work Plan is presented in the table below. It is based on an assumed date of NCDEQ Work Plan approval of 8 January 2024. The actual fieldwork schedule may shift earlier or later based on subcontractor availability or if unforeseen conditions are encountered in the field. Haley & Aldrich will notify Duke Energy of changes to the proposed schedule, which will then be communicated to NCDEQ. Milestone Date NCDEQ Work Plan approval 8 January 2024 Install transducers in existing wells 22 January 2024 Mobilize for field work 1 April 2024 Complete field work 28 June 2024 Receive laboratory reports and survey results 12 July 2024 Submit final report to NCDEQ 15 December 2024 11 '%RICH References 1. S&ME, 2023. Semi -Annual Water Quality Monitoring Report, January 2023 Sampling event, Duke Energy Carolinas, McGuire Landfill No. 1 (Unlined). 2. NCDEQ Division of Waste Management Solid Wastes Section, Revised April 2008. Guidelines for Groundwater, Soil, and Surface Water Sampling 3. Wood Environment & Infrastructure Solutions, Inc. (Wood), 2021. Site Characterization Report, 6004-INDUS Duke Energy Carolinas Landfill No. 1 (McGuire) (Unlined). 21 May 2021 https://haleyaIdrich.sharepoint.com/sites/Duke-0209037.McGuireNC/Shared Docu ments/0209037. McGuire NC/000- LF 1 BR GW/001- Work Plan/2023-1201_Duke McGuire Work Plan-F.docx 12 '%RICH TABLES TABLE 1 PROPOSED SCOPE OF WORK SUMMARY TABLE MCGUIRE LANDFILL MECKLENBURG COUNTY, NORTH CAROLINA ID Hydrogeologic Unit Borehole Depth (ft bgs) Screen Interval (ft bgs) Ground Surface Elevation* Screen Elevation (ft MSL) Outer Casing Depth (ft bgs) Depth to Water (Jan'23) (ft bTOC) used Monitoring Wells 13 Water Table -55 45 - 55 712 667 - 657 -- -- 3BRR Bedrock -195 TBD - TBD 725 TBD - TBD -125 -- 14 Water Table -50 40 - 50 700 660 - 650 -- -- 14D Basal Saprolite/Transition Zone -70 60 - 70 700 640 - 630 -- -- 14BR Bedrock -155 TBD - TBD 700 TBD - TBD -115 -- 15 Water Table -35 25 - 35 695 670 - 660 -- -- 15D Basal Saprolite/Transition Zone -70 60 - 70 695 635 - 625 -- -- 15BR Bedrock -155 TBD - TBD 695 TBD - TBD -110 -- 16 Water Table -40 30 - 40 708 678 - 668 -- -- 16D Basal Saprolite/Transition Zone -80 70 - 80 708 638 - 628 -- -- 16BR Bedrock -155 TBD - TBD 708 TBD - TBD -125 -- ing Monitoring Wells 1 Water Table 67.4 55.6 - 65.6 729.58 674.0 - 664.0 -- 30.21 1D Basal Saprolite/Transition Zone 90.4 75 - 85 729.75 654.8 - 644.8 -- 31.70 2A Water Table 78 65.1 - 75.1 736.96 671.9 - 661.9 -- 54.40 2D Basal Saprolite/Transition Zone 110.1 95.2 - 105.2 737.41 642.2 - 632.2 -- 55.21 3 Water Table 71 60 - 70 724.98 665.0 - 655.0 -- 58.18 3D Basal Saprolite/Transition Zone 86 75 - 85 724.98 650.0 - 640.0 -- 58.30 3611 Bedrock 175 123 - 128 732.94 609.9 - 604.9 111 65.89 4 Water Table 71 60 - 70 738.4 678.4 - 668.4 -- 67.40 4D Basal Saprolite/Transition Zone 98.8 88.3 - 98.3 738.25 650.0 - 640.0 -- 67.27 4BR Bedrock 175 167 - 172 739.09 572.1 - 567.1 110 71.61 411 Water Table Zone 43 28 - 43 711.15 683.2 - 668.2 -- 41.19 4DR Basal Saprolite/Transition Zone 87.6 72 - 87 711.15 639.2 - 624.2 -- 40.41 4BRR Bedrock 178 145.5 - 150.5 710.82 565.3 - 560.3 124 52.73 11 Water Table Zone 35.5 25.5 - 35.5 720.1 694.6 - 684.6 -- 30.50 11D Basal Saprolite/Transition Zone 100 88.5 - 98.5 720.84 632.3 - 622.3 -- 31.61 11BR Bedrock 221 197 - 202 723.65 526.7 - 521.7 158.5 36.26 12 Water Table Zone 27 12 - 27 722.21 710.2 - 695.2 -- 28.55 12D Basal Saprolite/Transition Zone 68.5 56 - 66 722.21 666.2 - 656.2 -- 26.70 13D Basal Saprolite/Transition Zone 90.1 80 - 90 712.4 632.4 - 622.4 -- 46.30 13BR Bedrock Zone 175 152.5 - 157.5 711.49 559.0 - 554.0 110 50.28 Notes Depths listed for proposed monitoring wells are estimates and may change based on field observations -- indicates not applicable ft bgs = feet below ground surface ft MSL = feet above mean seal level ft bTOC = feet below top of casing TBD = to be determined * Ground surface for proposed wells estimated based on nearby wells or surface elevations shown on Figure 2 Depth to water measured 1123123- 1124123 (S&ME, 2013) PAGE 1 OF 1 HALEY & ALDRICH, INC. https:Hhaleyaldrich.sharepoint.com/sites/Duke-0209037.McGuireNC/Shared Documents/0209037.McGuire NC/000 - LF 1 BR GW/001- Work Plan/20230-1201_Tablel-Scope of Work Summary_F.xlsx DECEMBER 2023 FIGURES 80°57'0"W 80°55'50"W 35°26'10"N 35°25'0"N 35°23'50"N p NC LAKE NORMAN 1 � MCGUIRE �. NUCLEAR STATION NUCLEAR STATION PROPERTY BOUNDARY NUCLEAR y 1 STATION J GARAGE / PROPERTY BOUNDARY LANDFILL NO. 1 (SITE) rN► r=• MAP SOURCE: NEARMAP, 6 FEBRUARY 2023 SITE COORDINATES: 35°25'09"N, 80°56'57"W / MW-14 / MW-14D / MW-14BR AW-3BRR • /MW13 MW-13 ' • MW-3BR `�•�• 670MW-13B �, o 70 0 /MW-4BRR •�� 1 MW-4W-4 •. � o MW-151 MW-A MW-4BR MW-151) W-4DR MW-15BR 1 I Ao- MW-2 `'• rno I MW2D ``� 0 1 � - MW-16I LANDFILL MW-16D . NO. 1 tMW-16BR • m BR � MW- WID MW-11D •�3`• �� 73'03, J-7fo .�� /730' O� MW-12�"�..��..� -- MW-12D / ; VQ 0 125 250 — _ _ � SCALE IN FEET LEGEND //++ DUKE ENERGY CAROLINAS MCGUIRE LANDFILL OPROPOSED WELL OR WELL �.. REVIEW BOUNDARY'�+N MECKLENBURG COUNTY, NORTH CAROLINA • CLUSTER LOCATION L LIMITS OF WASTE MONITORING WELL ELEVATION CONTOUR, NOTES STREET 10-FOOT 1. ALL DIMENSIONS AND LOCATIONS ARE APPROXIMATE. PROPOSED WELL LOCATION MAP ELEVATION CONTOUR, 2-FOOT 2. PWR = PARTIALLY WEATHERED ROCK STREAM 3. EXISTING WELL LOCATIONS, BOUNDARY, AND STREAM WERE PROVIDED BY DUKE ENERGY. • COMPLIANCE BOUNDARY DUKE ENERGY 4. AERIAL IMAGERY SOURCE: NEARMAP, 6 FEBRUARY 2023 ri PROPERTY BOUNDARY NOVEMBER2023 FIGURE 2 5 APPENDIX A Groundwater Contour Maps January 2023 (S&ME, March 2023) _t, 3— ji • 6'lbl�5' (01 �o ' MVI-411 673.73' , 672;68' ll I-- 685.27' '%" / `LANDFILL \\ NO. 1 .440 I \` A0 0. 0'2 / 692.10' W-12 0 696.26' r / NOTES: GIS BASE LAYERS WERE OBTAINED FROM THE OWNER AND ESRI. THIS MAP IS FOR INFORMATIONAL PURPOSES ONLY. ALL FEATURE LOCATIONS DISPLAYED ARE APPROXIMATED. THEY ARE NOT BASED ON CIVIL SURVEY INFORMATION, UNLESS STATED OTHERWISE. 200 400 GRAPHIC SCALE (IN FEET) t ►, LEGEND 0 SHALLOW GROUNDWATER MONITORING LOCATION ►-►-► STREAMS WITH FLOW DIRECTION 0- GROUNDWATER FLOW DIRECTION — • GROUNDWATER CONTOUR - JULY 2022 LANDFILL NO. 1 COMPLIANCE BOUNDARY LANDFILL NO. 1 LIMITS OF WASTE LANDFILL NO. 1 REVIEW BOUNDARY DUKE ENERGY PROPERTY BOUNDARY STREETS 2' CONTOURS 10' CONTOURS Q z 0 Q V ccl z Z O V 0 ca w J Y V w ►0 SCALE: 1=200' DATE: 2-17-2023 PROJECT NUMBER: 22350902, PH. 01 FIGURE NO 3 APPENDIX B NCDEQ Solid Waste Section Guidelines for Groundwater, Soil and Surface Water Sampling Solid Waste Section Guidelines for Groundwater, Soil, and Surface Water Sampling STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WASTE MANAGEMENT SOLID WASTE SECTION General Sampling Procedures The following guidance is provided to insure a consistent sampling approach so that sample collection activities at solid waste management facilities provide reliable data. Sampling must begin with an evaluation of facility information, historical environmental data and site geologic and hydrogeologic conditions. General sampling procedures are described in this document. Planning Begin sampling activities with planning and coordination. The party contracting with the laboratory is responsible for effectively communicating reporting requirements and evaluating data reliability as it relates to specific monitoring activities. Sample Collection Contamination Prevention a.) Take special effort to prevent cross contamination or environmental contamination when collecting samples. 1. If possible, collect samples from the least contaminated sampling location (or background sampling location, if applicable) to the most contaminated sampling location. 2. Collect the ambient or background samples first, and store them in separate ice chests or separate shipping containers within the same ice chest (e.g. untreated plastic bags). 3. Collect samples in flowing water at designated locations from upstream to downstream. b.) Do not store or ship highly contaminated samples (concentrated wastes, free product, etc.) or samples suspect of containing high concentrations of contaminants in the same ice chest or shipping containers with other environmental samples. 1. Isolate these sample containers by sealing them in separate, untreated plastic bags immediately after collecting, preserving, labeling, etc. 2. Use a clean, untreated plastic bag to line the ice chest or shipping container. c.) All sampling equipment should be thoroughly decontaminated and transported in a manner that does not allow it to become contaminated. Arrangements should be made ahead of time to decontaminate any sampling or measuring equipment that will be reused when taking samples from more than one well. Field decontamination of Rev 4-08 sampling equipment will be necessary before sampling each well to minimize the risk of cross contamination. Decontamination procedures should be included in reports as necessary. Certified pre -cleaned sampling equipment and containers may be used. When collecting aqueous samples, rinse the sample collection equipment with a portion of the sample water before taking the actual sample. Sample containers do not need to be rinsed. In the case of petroleum hydrocarbons, oil and grease, or containers with pre -measured preservatives, the sample containers cannot be rinsed. d.) Place all fuel -powered equipment away from, and downwind of, any site activities (e.g., purging, sampling, decontamination). 1. If field conditions preclude such placement (i.e., the wind is from the upstream direction in a boat), place the fuel source(s) as far away as possible from the sampling activities and describe the conditions in the field notes. 2. Handle fuel (i.e., filling vehicles and equipment) prior to the sampling day. If such activities must be performed during sampling, the personnel must wear disposable gloves. 3. Dispense all fuels downwind. Dispose of gloves well away from the sampling activities. Filling Out Sample Labels Fill out label, adhere to vial and collect sample. Print legibly with indelible ink. At a minimum, the label or tag should identify the sample with the following information: 1. Sample location and/or well number 2. Sample identification number 3. Date and time of collection 4. Analysis required/requested 5. Sampler's initials 6. Preservative(s) used, if any [i.e., HCI, Na2S203, NO3, ice, etc.] 7. Any other pertinent information for sample identification Sample Collection Order Unless field conditions justify other sampling regimens, collect samples in the following order: 1. Volatile Organics and Volatile Inorganics 2. Extractable Organics, Petroleum Hydrocarbons, Aggregate Organics and Oil and Grease 3. Total Metals 4. Inorganic Nonmetallics, Physical and Aggregate Properties, and Biologicals 5. Microbiological NOTE: If the pump used to collect groundwater samples cannot be used to collect volatile or extractable organics then collect all other parameters and withdraw the pump and tubing. Then collect the volatile and extractable organics. Rev 4-08 Health and Safety Implement all local, state, and federal requirements relating to health and safety. Follow all local, state and federal requirements pertaining to the storage and disposal of any hazardous or investigation derived wastes. a.) The Solid Waste Section recommends wearing protective gloves when conducting all sampling activities. 1. Gloves serve to protect the sample collector from potential exposure to sample constituents, minimize accidental contamination of samples by the collector, and preserve accurate tare weights on preweighed sample containers. 2. Do not let gloves come into contact with the sample or with the interior or lip of the sample container. Use clean, new, unpowdered and disposable gloves. Various types of gloves may be used as long as the construction materials do not contaminate the sample or if internal safety protocols require greater protection. 3. Note that certain materials that may potentially be present in concentrated effluent can pass through certain glove types and be absorbed in the skin. Many vendor catalogs provide information about the permeability of different gloves and the circumstances under which the glove material might be applicable. The powder in powdered gloves can contribute significant contamination. Powdered gloves are not recommended unless it can be demonstrated that the powder does not interfere with the sample analysis. 4. Change gloves after preliminary activities, after collecting all the samples at a single sampling point, if torn or used to handle extremely dirty or highly contaminated surfaces. Properly dispose of all used gloves as investigation derived wastes. b.) Properly manage all investigation derived waste (IDW). 5. To prevent contamination into previously uncontaminated areas, properly manage all IDW. This includes all water, soil, drilling mud, decontamination wastes, discarded personal protective equipment (PPE), etc. from site investigations, exploratory borings, piezometer and monitoring well installation, refurbishment, abandonment, and other investigative activities. Manage all IDW that is determined to be RCRA-regulated hazardous waste according to the local, state and federal requirements. 6. Properly dispose of IDW that is not a RCRA-regulated hazardous waste but is contaminated above the Department's Soil Cleanup Target Levels or the state standards and/or minimum criteria for ground water quality. If the drill cuttings/mud orpurged well water is contaminated with hazardous waste, contact the DWM Hazardous Waste Section (919-508-8400) for disposal options. Maintain all containers holding IDW in good condition. Periodically inspect the containers for damage and ensure that all required labeling (DOT, RCRA, etc.) are clearly visible. Rev 4-08 Sample Storage and Transport Store samples for transport carefully. Pack samples to prevent from breaking and to maintain a temperature of approximately 4 degrees Celsius (°C), adding ice if necessary. Transport samples to a North Carolina -certified laboratory as soon as possible. Avoid unnecessary handling of sample containers. Avoid heating (room temperature or above, including exposure to sunlight) or freezing of the sample containers. Reduce the time between sample collection and delivery to a laboratory whenever possible and be sure that the analytical holding times of your samples can be met by the laboratory. a.) A complete chain -of -custody (COC) form must be maintained to document all transfers and receipts of the samples. Be sure that the sample containers are labeled with the sample location and/or well number, sample identification, the date and time of collection, the analysis to be performed, the preservative added (if any), the sampler's initials, and any other pertinent information for sample identification. The labels should contain a unique identifier (i.e., unique well numbers) that can be traced to the COC form. The details of sample collection must be documented on the COC. The COC must include the following: 1. Description of each sample (including QA/QC samples) and the number of containers (sample location and identification) 2. Signature of the sampler 3. Date and time of sample collection 4. Analytical method to be performed 5. Sample type (i.e., water or soil) 6. Regulatory agency (i.e., NCDENR/DWM — SW Section) 7. Signatures of all persons relinquishing and receiving custody of the samples 8. Dates and times of custody transfers b.) Pack samples so that they are segregated by site, sampling location or by sample analysis type. When COC samples are involved, segregate samples in coolers by site. If samples from multiple sites will fit in one cooler, they may be packed in the same cooler with the associated field sheets and a single COC form for all. Coolers should not exceed a maximum weight of 50 lbs. Use additional coolers as necessary. All sample containers should be placed in plastic bags (segregated by analysis and location) and completely surrounded by ice. 1. Prepare and place trip blanks in an ice filled cooler before leaving for the field. 2. Segregate samples by analysis and place in sealable plastic bags. 3. Pack samples carefully in the cooler placing ice around the samples. 4. Review the COC. The COC form must accompany the samples to the laboratory. The trip blank(s) must also be recorded on the COC form. 5. Place completed COC form in a waterproof bag, sealed and taped under the lid of the cooler. 6. Secure shipping containers with strapping tape to avoid accidental opening. 7. For COC samples, a tamper -proof seal may also be placed over the cooler lid or over a bag or container containing the samples inside the shipping cooler. Rev 4-08 4 8. "COC" or "EMERG" should be written in indelible ink on the cooler seal to alert sample receipt technicians to priority or special handling samples. 9. The date and sample handler's signature must also be written on the COC seal. 10. Deliver the samples to the laboratory or ship by commercial courier. NOTE: If transport time to the laboratory is not long enough to allow samples to be cooled to 4° C, a temperature reading of the sample source must be documented as the field temperature on the CDC form. A downward trend in temperature will be adequate even if cooling to 4° C is not achieved. The field temperature should always be documented if there is any question as to whether samples will have time to cool to 4° C during shipment. Thermometers must be calibrated annually against an NIST traceable thermometer and documentation must be retained. Rev 4-08 Appendix A - Decontamination of Field Equipment Decontamination of personnel, sampling equipment, and containers - before and after sampling - must be used to ensure collection of representative samples and to prevent the potential spread of contamination. Decontamination of personnel prevents ingestion and absorption of contaminants. It must be done with a soap and water wash and deionized or distilled water rinse. Certified pre -cleaned sampling equipment and containers may also be used. All previously used sampling equipment must be properly decontaminated before sampling and between sampling locations. This prevents the introduction of contamination into uncontaminated samples and avoids cross -contamination of samples. Cross -contamination can be a significant problem when attempting to characterize extremely low concentrations of organic compounds or when working with soils that are highly contaminated. Clean, solvent -resistant gloves and appropriate protective equipment must be worn by persons decontaminating tools and equipment. Cleaning Reagents Recommendations for the types and grades of various cleaning supplies are outlined below. The recommended reagent types or grades were selected to ensure that the cleaned equipment is free from any detectable contamination. a.) Detergents: Use Liqui-Nox (or a non -phosphate equivalent) or Alconox (or equivalent). Liqui-Nox (or equivalent) is recommended by EPA, although Alconox (or equivalent) may be substituted if the sampling equipment will not be used to collect phosphorus or phosphorus containing compounds. b.) Solvents: Use pesticide grade isopropanol as the rinse solvent in routine equipment cleaning procedures. This grade of alcohol must be purchased from a laboratory supply vendor. Rubbing alcohol or other commonly available sources of isopropanol are not acceptable. Other solvents, such as acetone or methanol, may be used as the final rinse solvent if they are pesticide grade. However, methanol is more toxic to the environment and acetone may be an analyte of interest for volatile organics. 1. Do not use acetone if volatile organics are of interest 2. Containerize all methanol wastes (including rinses) and dispose as a hazardous waste. Pre -clean equipment that is heavily contaminated with organic analytes. Use reagent grade acetone and hexane or other suitable solvents. Use pesticide grade methylene chloride when cleaning sample containers. Store all solvents away from potential sources of contamination. c.) Analyte-Free Water Sources: Analyte-free water is water in which all analytes of interest and all interferences are below method detection limits. Maintain documentation (such as results from equipment blanks) to demonstrate the reliability and purity of analyte-free water source(s). The source of the water must meet the requirements of the analytical method and must be free from the analytes of interest. In general, the following water types are associated with specific analyte groups: 1. Milli-Q (or equivalent polished water): suitable for all analyses. Rev 4-08 2. Organic free: suitable for volatile and extractable organics. 3. Deionized water: may not be suitable for volatile and extractable organics. 4. Distilled water: not suitable for volatile and extractable organics, metals or ultratrace metals. Use analyte-free water for blank preparation and the final decontamination water rinse. In order to minimize long-term storage and potential leaching problems, obtain or purchase analyte-free water just prior to the sampling event. If obtained from a source (such as a laboratory), fill the transport containers and use the contents for a single sampling event. Empty the transport container(s) at the end of the sampling event. Discard any analyte-free water that is transferred to a dispensing container (such as a wash bottle or pump sprayer) at the end of each sampling day. d.) Acids: 1. Reagent Grade Nitric Acid: 10 - 15% (one volume concentrated nitric acid and five volumes deionized water). Use for the acid rinse unless nitrogen components (e.g., nitrate, nitrite, etc.) are to be sampled. If sampling for ultra -trace levels of metals, use an ultra -pure grade acid. 2. Reagent Grade Hydrochloric Acid: 10% hydrochloric acid (one volume concentrated hydrochloric and three volumes deionized water). Use when nitrogen components are to be sampled. 3. If samples for both metals and the nitrogen -containing components are collected with the equipment, use the hydrochloric acid rinse, or thoroughly rinse with hydrochloric acid after a nitric acid rinse. If sampling for ultra trace levels of metals, use an ultra -pure grade acid. 4. Freshly prepared acid solutions may be recycled during the sampling event or cleaning process. Dispose of any unused acids according to local ordinances. Reagent Storage Containers The contents of all containers must be clearly marked. a.) Detergents: 1. Store in the original container or in a HDPE or PP container. b.) Solvents: 1. Store solvents to be used for cleaning or decontamination in the original container until use in the field. If transferred to another container for field use, use either a glass or Teflon container. 2. Use dispensing containers constructed of glass, Teflon or stainless steel. Note: If stainless steel sprayers are used, any gaskets that contact the solvents must be constructed of inert materials. c.) Analyte-Free Water: 1. Transport in containers appropriate for the type of water stored. If the water is commercially purchased (e.g., grocery store), use the original containers when transporting the water to the field. Containers made of glass, Teflon, polypropylene or HDPE are acceptable. 2. Use glass or Teflon to transport organic -free sources of water on -site. Polypropylene or HDPE may be used, but are not recommended. Rev 4-08 7 3. Dispense water from containers made of glass, Teflon, HDPE or polypropylene. 4. Do not store water in transport containers for more than three days before beginning a sampling event. 5. If working on a project that has oversight from EPA Region 4, use glass containers for the transport and storage of all water. 6. Store and dispense acids using containers made of glass, Teflon or plastic. General Requirements a.) Prior to use, clean/decontaminate all sampling equipment (pumps, tubing, lanyards, split spoons, etc.) that will be exposed to the sample. b.) Before installing, clean (or obtain as certified pre -cleaned) all equipment that is dedicated to a single sampling point and remains in contact with the sample medium (e.g., permanently installed groundwater pump). If you use certified pre -cleaned equipment no cleaning is necessary. 1. Clean this equipment any time it is removed for maintenance or repair. 2. Replace dedicated tubing if discolored or damaged. c.) Clean all equipment in a designated area having a controlled environment (house, laboratory, or base of field operations) and transport it to the field, pre -cleaned and ready to use, unless otherwise justified. d.) Rinse all equipment with water after use, even if it is to be field -cleaned for other sites. Rinse equipment used at contaminated sites or used to collect in -process (e.g., untreated or partially treated wastewater) samples immediately with water. e.) Whenever possible, transport sufficient clean equipment to the field so that an entire sampling event can be conducted without the need for cleaning equipment in the field. f.) Segregate equipment that is only used once (i.e., not cleaned in the field) from clean equipment and return to the in-house cleaning facility to be cleaned in a controlled environment. g.) Protect decontaminated field equipment from environmental contamination by securely wrapping and sealing with one of the following: 1. Aluminum foil (commercial grade is acceptable) 2. Untreated butcher paper 3. Clean, untreated, disposable plastic bags. Plastic bags may be used for all analyte groups except volatile and extractable organics. Plastic bags may be used for volatile and extractable organics, if the equipment is first wrapped in foil or butcher paper, or if the equipment is completely dry. Cleaning Sample Collection Equipment a.) On-Site/In-Field Cleaning — Cleaning equipment on -site is not recommended because environmental conditions cannot be controlled and wastes (solvents and acids) must be containerized for proper disposal. 1. Ambient temperature water may be substituted in the hot, sudsy water bath and hot water rinses. NOTE: Properly dispose of all solvents and acids. Rev 4-08 2. Rinse all equipment with water after use, even if it is to be field -cleaned for other sites. 3. Immediately rinse equipment used at contaminated sites or used to collect in -process (e.g., untreated or partially treated wastewater) samples with water. b.) Heavily Contaminated Equipment - In order to avoid contaminating other samples, isolate heavily contaminated equipment from other equipment and thoroughly decontaminate the equipment before further use. Equipment is considered heavily contaminated if it: 1. Has been used to collect samples from a source known to contain significantly higher levels than background. 2. Has been used to collect free product. 3. Has been used to collect industrial products (e.g., pesticides or solvents) or their byproducts. NOTE: Cleaning heavily contaminated equipment in the field is not recommended. c.) On -Site Procedures: 1. Protect all other equipment, personnel and samples from exposure by isolating the equipment immediately after use. 2. At a minimum, place the equipment in a tightly sealed, untreated, plastic bag. 3. Do not store or ship the contaminated equipment next to clean, decontaminated equipment, unused sample containers, or filled sample containers. 4. Transport the equipment back to the base of operations for thorough decontamination. 5. If cleaning must occur in the field, document the effectiveness of the procedure, collect and analyze blanks on the cleaned equipment. d.) Cleaning Procedures: 1. If organic contamination cannot be readily removed with scrubbing and a detergent solution, pre -rinse equipment by thoroughly rinsing or soaking the equipment in acetone. 2. Use hexane only if preceded and followed by acetone. 3. In extreme cases, it may be necessary to steam clean the field equipment before proceeding with routine cleaning procedures. 4. After the solvent rinses (and/or steam cleaning), use the appropriate cleaning procedure. Scrub, rather than soak, all equipment with sudsy water. If high levels of metals are suspected and the equipment cannot be cleaned without acid rinsing, soak the equipment in the appropriate acid. Since stainless steel equipment should not be exposed to acid rinses, do not use stainless steel equipment when heavy metal contamination is suspected or present. 5. If the field equipment cannot be cleaned utilizing these procedures, discard unless further cleaning with stronger solvents and/or oxidizing solutions is effective as evidenced by visual observation and blanks. 6. Clearly mark or disable all discarded equipment to discourage use. Rev 4-08 e.) General Cleaning - Follow these procedures when cleaning equipment under controlled conditions. Check manufacturer's instructions for cleaning restrictions and/or recommendations. 1. Procedure for Teflon, stainless steel and glass sampling equipment: This procedure must be used when sampling for ALL analyte groups. (Extractable organics, metals, nutrients, etc. or if a single decontamination protocol is desired to clean all Teflon, stainless steel and glass equipment.) Rinse equipment with hot tap water. Soak equipment in a hot, sudsy water solution (Liqui-Nox or equivalent). If necessary, use a brush to remove particulate matter or surface film. Rinse thoroughly with hot tap water. If samples for trace metals or inorganic analytes will be collected with the equipment that is not stainless steel, thoroughly rinse (wet all surfaces) with the appropriate acid solution. Rinse thoroughly with analyte-free water. Make sure that all equipment surfaces are thoroughly flushed with water. If samples for volatile or extractable organics will be collected, rinse with isopropanol. Wet equipment surfaces thoroughly with free - flowing solvent. Rinse thoroughly with analyte-free water. Allow to air dry. Wrap and seal as soon as the equipment has air-dried. If isopropanol is used, the equipment may be air-dried without the final analyte-free water rinse; however, the equipment must be completely dry before wrapping or use. Wrap clean sampling equipment according to the procedure described above. 2. General Cleaning Procedure for Plastic Sampling Equipment: Rinse equipment with hot tap water. Soak equipment in a hot, sudsy water solution (Liqui-Nox or equivalent). If necessary, use a brush to remove particulate matter or surface film. Rinse thoroughly with hot tap water. Thoroughly rinse (wet all surfaces) with the appropriate acid solution. Check manufacturer's instructions for cleaning restrictions and/or recommendations. Rinse thoroughly with analyte-free water. Be sure that all equipment surfaces are thoroughly flushed. Allow to air dry as long as possible. Wrap clean sampling equipment according to the procedure described above. Rev 4-08 10 Appendix B - Collecting Soil Samples Soil samples are collected for a variety of purposes. A methodical sampling approach must be used to assure that sample collection activities provide reliable data. Sampling must begin with an evaluation of background information, historical data and site conditions. Soil Field Screening Procedures Field screening is the use of portable devices capable of detecting petroleum contaminants on a real-time basis or by a rapid field analytical technique. Field screening should be used to help assess locations where contamination is most likely to be present. When possible, field -screening samples should be collected directly from the excavation or from the excavation equipment's bucket. If field screening is conducted only from the equipment's bucket, then a minimum of one field screening sample should be collected from each 10 cubic yards of excavated soil. If instruments or other observations indicate contamination, soil should be separated into stockpiles based on apparent degrees of contamination. At a minimum, soil suspected of contamination must be segregated from soil observed to be free of contamination. a.) Field screening devices — Many field screen instruments are available for detecting contaminants in the field on a rapid or real-time basis. Acceptable field screening instruments must be suitable for the contaminant being screened. The procdedure for field screening using photoionization detectors (PIDs) and flame ionization detectors (FIDs) is described below. If other instruments are used, a description of the instrument or method and its intended use must be provided to the Solid Waste Section. Whichever field screening method is chosen, its accuracy must be verified throughout the sampling process. Use appropriate standards that match the use intended for the data. Unless the Solid Waste Section indicates otherwise, wherever field screening is recommended in this document, instrumental or analytical methods of detection must be used, not olfactory or visual screening methods. b.) Headspace analytical screening procedure for filed screening (semi -quantitative field screening) - The most commonly used field instruments for Solid Waste Section site assessments are FIDs and PIDs. When using FIDs and PIDs, use the following headspace screening procedure to obtain and analyze field -screening samples: 1. Partially fill (one-third to one-half) a clean jar or clean ziplock bag with the sample to be analyzed. The total capacity of the jar or bag may not be less than eight ounces (app. 250 ml), but the container should not be so large as to allow vapor diffusion and stratification effects to significantly affect the sample. 2. If the sample is collected from a spilt -spoon, it must be transferred to the jar or bag for headspace analysis immediately after opening the split - spoon. If the sample is collected from an excavation or soil pile, it must be collected from freshly uncovered soil. Rev 4-08 11 3. If a jar is used, it must be quickly covered with clean aluminum foil or a jar lid; screw tops or thick rubber bands must be used to tightly seal the jar. If a zip lock bag is used, it must be quickly sealed shut. 4. Headspace vapors must be allowed to develop in the container for at least 10 minutes but no longer than one hour. Containers must be shaken or agitated for 15 seconds at the beginning and the end of the headspace development period to assist volatilization. Temperatures of the headspace must be warmed to at least 5° C (approximately 40' F) with instruments calibrated for the temperature used. 5. After headspace development, the instrument sampling probe must be inserted to a point about one-half the headspace depth. The container opening must be minimized and care must be taken to avoid the uptake of water droplets and soil particulates. 6. After probe insertion, the highest meter reading must be taken and recorded. This will normally occur between two and five seconds after probe insertion. If erratic meter response occurs at high organic vapor concentrations or conditions of elevated headspace moisture, a note to that effect must accompany the headspace data. 7. All field screening results must be documented in the field record or log book. Soil Sample Collection Procedures for Laboratory Samples The number and type of laboratory samples collected depends on the purpose of the sampling activity. Samples analyzed with field screening devices may not be substituted for required laboratory samples. a.) General Sample Collection - When collecting samples from potentially contaminated soil, care should be taken to reduce contact with skin or other parts of the body. Disposable gloves should be worn by the sample collector and should be changed between samples to avoid cross -contamination. Soil samples should be collected in a manner that causes the least disturbance to the internal structure of the sample and reduces its exposure to heat, sunlight and open air. Likewise, care should be taken to keep the samples from being contaminated by other materials or other samples collected at the site. When sampling is to occur over an extended period of time, it is necessary to insure that the samples are collected in a comparable manner. All samples must be collected with disposable or clean tools that have been decontaminated. Disposable gloves must be worn and changed between sample collections. Sample containers must be filled quickly. Soil samples must be placed in containers in the order of volatility, for example, volatile organic aromatic samples must be taken first, organics next, then heavier range organics, and finally soil classification samples. Containers must be quickly and adequately sealed, and rims must be cleaned before tightening lids. Tape may be used only if known not to affect sample analysis. Sample containers must be clearly labeled. Containers must immediately be preserved according to procedures in this Section. Unless specified Rev 4-08 12 otherwise, at a minimum, the samples must be immediately cooled to 4 ± 2°C and this temperature must be maintained throughout delivery to the laboratory. b.) Surface Soil Sampling - Surface soil is generally classified as soil between the ground surface and 6-12 inches below ground surface. Remove leaves, grass and surface debris from the area to be sampled. Select an appropriate, pre -cleaned sampling device and collect the sample. Transfer the sample to the appropriate sample container. Clean the outside of the sample container to remove excess soil. Label the sample container, place on wet ice to preserve at 4°C, and complete the field notes. c.) Subsurface Soil Sampling — The interval begins at approximately 12 inches below ground surface. Collect samples for volatile organic analyses. For other analyses, select an appropriate, pre -cleaned sampling device and collect the sample. Transfer the sample to the appropriate sample container. Clean the outside of the sample container to remove excess soil. Label the sample container, place on wet ice to preserve at 4°C, and complete field notes. d.) Equipment for Reachingthe Appropriate Soil Sampling Depth - Samples may be collected using a hollow stem soil auger, direct push, Shelby tube, split -spoon sampler, or core barrel. These sampling devices may be used as long as an effort is made to reduce the loss of contaminants through volatilization. In these situations, obtain a sufficient volume of so the samples can be collected without volatilization and disturbance to the internal structure of the samples. Samples should be collected from cores of the soil. Non -disposable sampling equipment must be decontaminated between each sample location. NOTE: If a confining layer has been breached during sampling, grout the hole to land. e.) Equipment to Collect Soil Samples - Equipment and materials that may be used to collect soil samples include disposable plastic syringes and other "industry -standard" equipment and materials that are contaminant -free. Non -disposable sampling equipment must be decontaminated between each sample location. Rev 4-08 13 Appendix C - Collecting Groundwater Samples Groundwater samples are collected to identify, investigate, assess and monitor the concentration of dissolved contaminant constituents. To properly assess groundwater contamination, first install sampling points (monitoring wells, etc.) to collect groundwater samples and then perform specific laboratory analyses. All monitoring wells should be constructed in accordance with 15A NCAC 2C .0100 and sampled as outlined in this section. Groundwater monitoring is conducted using one of two methods: 1. Portable Monitoring: Monitoring that is conducted using sampling equipment that is discarded between sampling locations. Equipment used to collect a groundwater sample from a well such as bailers, tubing, gloves, and etc. are disposed of after sample collection. A new set of sampling equipment is used to collect a groundwater sample at the next monitor well. 2. Dedicated Monitoriniz: Monitoring that utilizes permanently affixed down -well and well head components that are capped after initial set-up. Most dedicated monitoring systems are comprised of an in -well submersible bladder pump, with air supply and sample discharge tubing, and an above -ground driver/controller for regulation of flow rates and volumes. The pump and all tubing housed within the well should be composed of Teflon or stainless steel components. This includes seals inside the pump, the pump body, and fittings used to connect tubing to the pump. Because ground water will not be in contact with incompatible constituents and because the well is sealed from the surface, virtually no contamination is possible from intrinsic sources during sampling and between sampling intervals. All dedicated monitoring systems must be approved by the Solid Waste Section before installation. Groundwater samples may be collected from a number of different configurations. Each configuration is associated with a unique set of sampling equipment requirements and techniques: 1. Wells without Plumbing: These wells require equipment to be brought to the well to purge and sample unless dedicated equipment is placed in the well. 2. Wells with In -Place Plumbing: Wells with in -place plumbing do not require equipment to be brought to the well to purge and sample. In -place plumbing is generally considered permanent equipment routinely used for purposes other than purging and sampling, such as for water supply. 3. Air Strippers or Remedial Systems: These types of systems are installed as remediation devices. Rev 4-08 14 Groundwater Sample Preparation The type of sample containers used depends on the type of analysis performed. First, determine the type(s) of contaminants expected and the proper analytical method(s). Be sure to consult your selected laboratory for its specific needs and requirements prior to sampling. Next, prepare the storage and transport containers (ice chest, etc.) before taking any samples so that each sample can be placed in a chilled environment immediately after collection. Use groundwater purging and sampling equipment constructed of only non -reactive, non - leachable materials that are compatible with the environment and the selected analytes. In selecting groundwater purging and sampling equipment, give consideration to the depth of the well, the depth to groundwater, the volume of water to be evacuated, the sampling and purging technique, and the analytes of interest. Additional supplies, such as reagents and preservatives, may be necessary. All sampling equipment (bailers, tubing, containers, etc.) must be selected based on its chemical compatibility with the source being sampled (e.g., water supply well, monitoring well) and the contaminants potentially present. a.) Pumps - All pumps or pump tubing must be lowered and retrieved from the well slowly and carefully to minimize disturbance to the formation water. This is especially critical at the air/water interface. 1. Above -Ground Pumps • Variable Speed Peristaltic Pump: Use a variable speed peristaltic pump to purge groundwater from wells when the static water level in the well is no greater than 20- 25 feet below land surface (BLS). If the water levels are deeper than 18-20 feet BLS, the pumping velocity will decrease. A variable speed peristaltic pump can be used for normal purging and sampling, and sampling low permeability aquifers or formations. Most analyte groups can be sampled with a peristaltic pump if the tubing and pump configurations are appropriate. • Variable Speed Centrifugal Pump: A variable speed centrifugal pump can be used to purge groundwater from 2-inch and larger internal diameter wells. Do not use this type of pump to collect groundwater samples. When purging is complete, do not allow the water that remains in the tubing to fall back into the well. Install a check valve at the end of the purge tubing. 2. Submersible Pumps • Variable Speed Electric Submersible Pump: A variable speed submersible pump can be used to purge and sample groundwater from 2-inch and larger internal diameter wells. A variable speed submersible pump can be used for normal purging and sampling, and sampling low permeability aquifers or formations. The pump housing, fittings, check valves and associated hardware must be constructed of stainless steel. All other materials must be Rev 4-08 15 b.) Bailers compatible with the analytes of interest. Install a check valve at the output side of the pump to prevent backflow. If purging and sampling for organics, the entire length of the delivery tube must be Teflon, polyethylene or polypropylene (PP) tubing; the electrical cord must be sealed in Teflon, polyethylene or PP and any cabling must be sealed in Teflon, polyethylene or PP, or be constructed of stainless steel; and all interior components that contact the sample water (impeller, seals, gaskets, etc.) must be constructed of stainless steel or Teflon. 3. Variable Speed Bladder Pump: A variable speed, positive displacement, bladder pump can be used to purge and sample groundwater from 3/4-inch and larger internal diameter wells. • A variable speed bladder pump can be used for normal purging and sampling, and sampling low permeability aquifers or formations. • The bladder pump system is composed of the pump, the compressed air tubing, the water discharge tubing, the controller and a compressor, or a compressed gas supply. • The pump consists of a bladder and an exterior casing or pump body that surrounds the bladder and two (2) check valves. These parts can be composed of various materials, usually combinations of polyvinyl chloride (PVC), Teflon, polyethylene, PP and stainless steel. Other materials must be compatible with the analytes of interest. • If purging and sampling for organics, the pump body must be constructed of stainless steel. The valves and bladder must be Teflon, polyethylene or PP; the entire length of the delivery tube must be Teflon, polyethylene or PP; and any cabling must be sealed in Teflon, polyethylene or PP, or be constructed of stainless steel. • Permanently installed pumps may have a PVC pump body as long as the pump remains in contact with the water in the well. I. Purging: Bailers must be used with caution because improper bailing can cause changes in the chemistry of the water due to aeration and loosening particulate matter in the space around the well screen. Use a bailer if there is non -aqueous phase liquid (free product) in the well or if non -aqueous phase liquid is suspected to be in the well. 2. Sampling: Bailers must be used with caution. 3. Construction and Type: Bailers must be constructed of materials compatible with the analytes of interest. Stainless steel, Teflon, rigid medical grade PVC, polyethylene and PP bailers may be used to sample all analytes. Use disposable bailers when sampling grossly contaminated sample sources. NCDENR recommends using dual check valve bailers when collecting samples. Use bailers with a controlled flow bottom to collect volatile organic samples. Rev 4-08 16 4. Contamination Prevention: Keep the bailer wrapped (foil, butcher paper, etc.) until just before use. Use protective gloves to handle the bailer once it is removed from its wrapping. Handle the bailer by the lanyard to minimize contact with the bailer surface. c.) Lans 1. Lanyards must be made of non -reactive, non -leachable material. They may be cotton twine, nylon, stainless steel, or may be coated with Teflon, polyethylene or PP. 2. Discard cotton twine, nylon, and non -stainless steel braided lanyards after sampling each monitoring well. 3. Decontaminate stainless steel, coated Teflon, polyethylene and PP lanyards between monitoring wells. They do not need to be decontaminated between purging and sampling operations. Water Level and Purge Volume Determination The amount of water that must be purged from a well is determined by the volume of water and/or field parameter stabilization. a.) General Equipment Considerations - Selection of appropriate purging equipment depends on the analytes of interest, the well diameter, transmissivity of the aquifer, the depth to groundwater, and other site conditions. 1. Use of a pump to purge the well is recommended unless no other equipment can be used or there is non -aqueous phase liquid in the well, or non -aqueous phase liquid is suspected to be in the well. 2. Bailers must be used with caution because improper bailing: • Introduces atmospheric oxygen, which may precipitate metals (i.e., iron) or cause other changes in the chemistry of the water in the sample (i.e., pH). • Agitates groundwater, which may bias volatile and semi - volatile organic analyses due to volatilization. • Agitates the water in the aquifer and resuspends fine particulate matter. • Surges the well, loosening particulate matter in the annular space around the well screen. • May introduce dirt into the water column if the sides of the casing wall are scraped. NOTE: It is critical for bailers to be slowly and gently immersed into the top of the water column, particularly during the final stages of purging. This minimizes turbidity and disturbance of volatile organic constituents. b.) Initial Inspection 1. Remove the well cover and remove all standing water around the top of the well casing (manhole) before opening the well. 2. Inspect the exterior protective casing of the monitoring well for damage. Document the results of the inspection if there is a problem. 3. It is recommended that you place a protective covering around the well head. Replace the covering if it becomes soiled or ripped. Rev 4-08 17 4. Inspect the well lock and determine whether the cap fits tightly. Replace the cap if necessary. c.) Water Level Measurements - Use an electronic probe or chalked tape to determine the water level. Decontaminate all equipment before use. Measure the depth to groundwater from the top of the well casing to the nearest 0.01 foot. Always measure from the same reference point or survey mark on the well casing. Record the measurement. I. Electronic Probe: Decontaminate all equipment before use. Follow the manufacturer's instructions for use. Record the measurement. 2. Chalked Line Method: Decontaminate all equipment before use. Lower chalked tape into the well until the lower end is in the water. This is usually determined by the sound of the weight hitting the water. Record the length of the tape relative to the reference point. Remove the tape and note the length of the wetted portion. Record the length. Determine the depth to water by subtracting the length of the wetted portion from the total length. Record the result. d.) Water Column Determination - To determine the length of the water column, subtract the depth to the top of the water column from the total well depth (or gauged well depth if silting has occurred). The total well depth depends on the well construction. If gauged well depth is used due to silting, report total well depth also. Some wells may be drilled in areas of sinkhole, karst formations or rock leaving an open borehole. Attempt to find the total borehole depth in cases where there is an open borehole below the cased portion. e.) Well Water Volume - Calculate the total volume of water, in gallons, in the well using the following equation: V = (0.041)d x d x h Where: V = volume in gallons d = well diameter in inches h = height of the water column in feet The total volume of water in the well may also be determined with the following equation by using a casing volume per foot factor (Gallons per Foot of Water) for the appropriate diameter well: V = [Gallons per Foot of Water] x h Where: V = volume in gallons h = height of the water column in feet Record all measurements and calculations in the field records. f.) Purging Equipment Volume - Calculate the total volume of the pump, associated tubing and flow cell (if used), using the following equation: V= p + ((0.041)d x dx 1)+fc Where: V = volume in gallons p = volume of pump in gallons d = tubing diameter in inches 1= length of tubing in feet Rev 4-08 18 fc = volume of flow cell in gallons g.) If the groundwater elevation data are to be used to construct groundwater elevation contour maps, all water level measurements must be taken within the same 24 hour time interval when collecting samples from multiple wells on a site, unless a shorter time period is required. If the site is tidally influenced, complete the water level measurements within the time frame of an incoming or outgoing tide. Well Purging Techniques The selection of the purging technique and equipment is dependent on the hydrogeologic properties of the aquifer, especially depth to groundwater and hydraulic conductivity. a.) Measuring the Purge Volume - The volume of water that is removed during purging must be recorded. Therefore, you must measure the volume during the purging operation. 1. Collect the water in a graduated container and multiply the number of times the container was emptied by the volume of the container, OR 2. Estimate the volume based on pumping rate. This technique may be used only if the pumping rate is constant. Determine the pumping rate by measuring the amount of water that is pumped for a fixed period of time, or use a flow meter. • Calculate the amount of water that is discharged per minute: D = Measured Amount/Total Time In Minutes • Calculate the time needed to purge one (1) well volume or one (1) purging equipment volume: Time = V/D Where: V = well volume or purging equipment volume D = discharge rate • Make new measurements each time the pumping rate is changed. 3. Use a totalizing flow meter. • Record the reading on the totalizer prior to purging. • Record the reading on the totalizer at the end of purging. • To obtain the volume purged, subtract the reading on the totalizer prior to purging from the reading on the totalizer at the end of purging. • Record the times that purging begins and ends in the field records. b.) Purging Measurement Frequency - When purging a well that has the well screen fully submerged and the pump or intake tubing is placed within the well casing above the well screen or open hole, purge a minimum of one (1) well volume prior to collecting measurements of the field parameters. Allow at least one quarter (1/4) well volume to purge between subsequent measurements. When purging a well that has the pump or intake tubing placed within a fully submerged well screen or open hole, purge until the water level has stabilized (well recovery rate equals the purge rate), then purge a minimum of one (1) volume of the pump, associated tubing and flow cell (if used) prior to collecting measurements of the field parameters. Take measurements of the field parameters no sooner than two (2) to three (3) minutes apart. Purge at least Rev 4-08 19 three (3) volumes of the pump, associated tubing and flow cell, if used, prior to collecting a sample. When purging a well that has a partially submerged well screen, purge a minimum of one (1) well volume prior to collecting measurements of the field parameters. Take measurements of the field parameters no sooner than two (2) to three (3) minutes apart. c.) Purging ompletion - Wells must be adequately purged prior to sample collection to ensure representation of the aquifer formation water, rather than stagnant well water. This may be achieved by purging three volumes from the well or by satisfying any one of the following three purge completion criteria: 1.) Three (3) consecutive measurements in which the three (3) parameters listed below are within the stated limits, dissolved oxygen is no greater than 20 percent of saturation at the field measured temperature, and turbidity is no greater than 20 Nephelometric Turbidity Units (NTUs). • Temperature: + 0.2° C • pH: + 0.2 Standard Units • Specific Conductance: + 5.0% of reading Document and report the following, as applicable. The last four items only need to be submitted once: • Purging rate. • Drawdown in the well, if any. • A description of the process and the data used to design the well. • The equipment and procedure used to install the well. • The well development procedure. • Pertinent lithologic or hydrogeologic information. 2.) If it is impossible to get dissolved oxygen at or below 20 percent of saturation at the field measured temperature or turbidity at or below 20 NTUs, then three (3) consecutive measurements of temperature, pH, specific conductance and the parameter(s) dissolved oxygen and/or turbidity that do not meet the requirements above must be within the limits below. The measurements are: • Temperature: + 0.2° C • pH: + 0.2 Standard Units • Specific Conductance: + 5.0% of reading • Dissolved Oxygen: + 0.2 mg/L or 10%, whichever is greater • Turbidity: + 5 NTUs or 10%, whichever is greater Additionally, document and report the following, as applicable, except that the last four(4) items only need to be submitted once: • Purging rate. • Drawdown in the well, if any. • A description of conditions at the site that may cause the dissolved oxygen to be high and/or dissolved oxygen measurements made within the screened or open hole portion of the well with a downhole dissolved oxygen probe. Rev 4-08 20 • A description of conditions at the site that may cause the turbidity to be high and any procedures that will be used to minimize turbidity in the future. • A description of the process and the data used to design the well. • The equipment and procedure used to install the well. • The well development procedure. • Pertinent lithologic or hydrogeologic information. 3.) If after five (5) well volumes, three (3) consecutive measurements of the field parameters temperature, pH, specific conductance, dissolved oxygen, and turbidity are not within the limits stated above, check the instrument condition and calibration, purging flow rate and all tubing connections to determine if they might be affecting the ability to achieve stable measurements. It is at the discretion of the consultant/contractor whether or not to collect a sample or to continue purging. Further, the report in which the data are submitted must include the following, as applicable. The last four (4) items only need to be submitted once. • Purging rate. • Drawdown in the well, if any. • A description of conditions at the site that may cause the Dissolved Oxygen to be high and/or Dissolved Oxygen measurements made within the screened or open hole portion of the well with a downhole dissolved oxygen probe. • A description of conditions at the site that may cause the turbidity to be high and any procedures that will be used to minimize turbidity in the future. • A description of the process and the data used to design the well. • The equipment and procedure used to install the well. • The well development procedure. • Pertinent lithologic or hydrogeologic information. If wells have previously and consistently purged dry, and the current depth to groundwater indicates that the well will purge dry during the current sampling event, minimize the amount of water removed from the well by using the same pump to purge and collect the sample: • Place the pump or tubing intake within the well screened interval. • Use very small diameter Teflon, polyethylene or PP tubing and the smallest possible pump chamber volume. This will minimize the total volume of water pumped from the well and reduce drawdown. • Select tubing that is thick enough to minimize oxygen transfer through the tubing walls while pumping. Rev 4-08 21 • Pump at the lowest possible rate (100 mL/minute or less) to reduce drawdown to a minimum. • Purge at least two (2) volumes of the pumping system (pump, tubing and flow cell, if used). • Measure pH, specific conductance, temperature, dissolved oxygen and turbidity, then begin to collect the samples. Collect samples immediately after purging is complete. The time period between completing the purge and sampling cannot exceed six hours. If sample collection does not occur within one hour of purging completion, re -measure the five field parameters: temperature, pH, specific conductance, dissolved oxygen and turbidity, just prior to collecting the sample. If the measured values are not within 10 percent of the previous measurements, re -purge the well. The exception is "dry" wells. d.) Lanyards 1. Securely fasten lanyards, if used, to any downhole equipment (bailers, pumps, etc.). 2. Use bailer lanyards in such a way that they do not touch the ground surface. Wells Without Plumbing a.) Tubin /gip Placement 1. If attempting to minimize the volume of purge water, position the intake hose or pump at the midpoint of the screened or open hole interval. 2. If monitoring well conditions do not allow minimizing of the purge water volume, position the pump or intake hose near the top of the water column. This will ensure that all stagnant water in the casing is removed. 3. If the well screen or borehole is partially submerged, and the pump will be used for both purging and sampling, position the pump midway between the measured water level and the bottom of the screen. Otherwise, position the pump or intake hose near the top of the water column. b.) Non -dedicated (portable) pumps 1. Variable Speed Peristaltic Pump • Wear sampling gloves to position the decontaminated pump and tubing. • Attach a short section of tubing to the discharge side of the pump and into a graduated container. • Attach one end of a length of new or precleaned tubing to the pump head flexible hose. • Place the tubing as described in one of the options listed above. • Change gloves before beginning to purge. • Measure the depth to groundwater at frequent intervals. • Record these measurements. • Adjust the purging rate so that it is equivalent to the well recovery rate to minimize drawdown. Rev 4-08 22 • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdrawal rate with the recharge rate. • If the water table continues to drop during pumping, lower the tubing at the approximate rate of drawdown so that water is removed from the top of the water column. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. • Decontaminate the pump and tubing between wells (see Appendix C) or if precleaned tubing is used for each well, only the pump. 2. Variable Speed Centrifugal Pump • Position fuel powered equipment downwind and at least 10 feet from the well head. Make sure that the exhaust faces downwind. • Wear sampling gloves to position the decontaminated pump and tubing. • Place the decontaminated suction hose so that water is always pumped from the top of the water column. • Change gloves before beginning to purge. • Equip the suction hose with a foot valve to prevent purge water from re-entering the well. • Measure the depth to groundwater at frequent intervals. • Record these measurements. • To minimize drawdown, adjust the purging rate so that it is equivalent to the well recovery rate. • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdrawal rate with the recharge rate. • If the water table continues to drop during pumping, lower the tubing at the approximate rate of drawdown so that the water is removed from the top of the water column. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. • Decontaminate the pump and tubing between wells or if precleaned tubing is used for each well, only the pump. 3. Variable Speed Electric Submersible Pump • Position fuel powered equipment downwind and at least 10 feet from the well head. Make sure that the exhaust faces downwind. • Wear sampling gloves to position the decontaminated pump and tubing. • Carefully position the decontaminated pump. Rev 4-08 23 • Change gloves before beginning to purge. • Measure the depth to groundwater at frequent intervals. • Record these measurements. • To minimize drawdown, adjust the purging rate so that it is equivalent to the well recovery rate. • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdrawal rate with the recharge rate. • If the water table continues to drop during pumping, lower the tubing or pump at the approximate rate of drawdown so that water is removed from the top of the water column. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. • Decontaminate the pump and tubing between wells or only the pump if precleaned tubing is used for each well. 4. Variable Speed Bladder Pump • Position fuel powered equipment downwind and at least 10 feet from the well head. Make sure that the exhaust faces downwind. • Wear sampling gloves to position the decontaminated pump and tubing. • Attach the tubing and carefully position the pump. • Change gloves before beginning purging. • Measure the depth to groundwater at frequent intervals. • Record these measurements. • To minimize drawdown, adjust the purging rate so that it is equivalent to the well recovery rate. • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdrawal rate with the recharge rate. • If the water table continues to drop during pumping, lower the tubing or pump at the approximate rate of drawdown so that water is removed from the top of the water column. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. • Decontaminate the pump and tubing between wells or if precleaned tubing is used for each well, only the pump. c.) Dedicated Portable Pumps 1. Variable Speed Electric Submersible Pump • Position fuel powered equipment downwind and at least 10 feet from the well head. Make sure that the exhaust faces downwind. • Wear sampling gloves. Rev 4-08 24 • Measure the depth to groundwater at frequent intervals. • Record these measurements. • Adjust the purging rate so that it is equivalent to the well recovery rate to minimize drawdown. • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdraw with the recharge rate. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. 2. Variable Speed Bladder Pump • Position fuel powered equipment downwind and at least 10 feet from the well head. Make sure that the exhaust faces downwind. • Wear sampling gloves. • Measure the depth to groundwater at frequent intervals. • Record these measurements. • Adjust the purging rate so that it is equivalent to the well recovery rate to minimize drawdown. • If the purging rate exceeds the well recovery rate, reduce the pumping rate to balance the withdraw with the recharge rate. • Record the purging rate each time the rate changes. • Measure the purge volume. • Record this measurement. 3. Bailers - Using bailers for purging is not recommended unless care is taken to use proper bailing technique, or if free product is present in the well or suspected to be in the well. • Minimize handling the bailer as much as possible. • Wear sampling gloves. • Remove the bailer from its protective wrapping just before use. • Attach a lanyard of appropriate material. • Use the lanyard to move and position the bailer. • Lower and retrieve the bailer slowly and smoothly. • Lower the bailer carefully into the well to a depth approximately a foot above the water column. • When the bailer is in position, lower the bailer into the water column at a rate of 2 cm/sec until the desired depth is reached. • Do not lower the top of the bailer more than one (1) foot below the top of the water table so that water is removed from the top of the water column. • Allow time for the bailer to fill with aquifer water as it descends into the water column. Rev 4-08 25 • Carefully raise the bailer. Retrieve the bailer at the same rate of 2 cm/sec until the bottom of the bailer has cleared to top of the water column. • Measure the purge volume. • Record the volume of the bailer. • Continue to carefully lower and retrieve the bailer as described above until the purging is considered complete, based on either the removal of 3 well volumes. • Remove at least one (1) well volume before collecting measurements of the field parameters. Take each subsequent set of measurements after removing at least one quarter (1/4) well volume between measurements. Groundwater Sampling Techniques a.) Purge wells. b.) Replace protective covering around the well if it is soiled or torn after completing purging operations. c.) Equipment Considerations 1. The following pumps are approved to collect volatile organic samples: • Stainless steel and Teflon variable speed submersible PUMPS • Stainless steel and Teflon or polyethylene variable speed bladder pumps • Permanently installed PVC bodied pumps (As long as the pump remains in contact with the water in the well at all times) 2. Collect sample from the sampling device and store in sample container. Do not use intermediate containers. 3. To avoid contamination or loss of analytes from the sample, handle sampling equipment as little as possible and minimize equipment exposure to the sample. 4. To reduce chances of cross -contamination, use dedicated equipment whenever possible. "Dedicated" is defined as equipment that is to be used solely for one location for the life of that equipment (e.g., permanently mounted pump). Purchase dedicated equipment with the most sensitive analyte of interest in mind. • Clean or make sure dedicated pumps are clean before installation. They do not need to be cleaned prior to each use, but must be cleaned if they are withdrawn for repair or servicing. • Clean or make sure any permanently mounted tubing is clean before installation. • Change or clean tubing when the pump is withdrawn for servicing. • Clean any replaceable or temporary parts. Rev 4-08 26 • Collect equipment blanks on dedicated pumping systems when the tubing is cleaned or replaced. • Clean or make sure dedicated bailers are clean before placing them into the well. • Collect an equipment blank on dedicated bailers before introducing them into the water column. • Suspend dedicated bailers above the water column if they are stored in the well. Sampling Wells Without Plumbing a.) Sampling with Pumps — The following pumps may be used to sample for organics: • Peristaltic pumps • Stainless steel, Teflon or polyethylene bladder pumps • Variable speed stainless steel and Teflon submersible PUMPS Peristaltic Pump • Volatile Organics: One of three methods may be used. ■ Remove the drop tubing from the inlet side of the pump; submerge the drop tubing into the water column; prevent the water in the tubing from flowing back into the well; remove the drop tubing from the well; carefully allow the groundwater to drain into the sample vials; avoid turbulence; do not aerate the sample; repeat steps until enough vials are filled. OR ■ Use the pump to fill the drop tubing; quickly remove the tubing from the pump; prevent the water in the tubing from flowing back into the well; remove the drop tubing from the well; carefully allow the groundwater to drain into the sample vials; avoid turbulence; do not aerate the sample; repeat steps until enough vials are filled. OR ■ Use the pump to fill the drop tubing; withdraw the tubing from the well; reverse the flow on the peristaltic pumps to deliver the sample into the vials at a slow, steady rate; repeat steps until enough vials are filled. • Extractable Organics: If delivery tubing is not polyethylene or PP, or is not Teflon lined, use pump and vacuum trap method. Connect the outflow tubing from the container to the influent side of the peristaltic pump. Turn pump on and reduce flow until smooth and even. Discard a Rev 4-08 27 small portion of the sample to allow for air space. Preserve (if required), label, and complete field notes. • Inorganic samples: These samples may be collected from the effluent tubing. If samples are collected from the pump, decontaminate all tubing (including the tubing in the head) or change it between wells. Preserve (if required), label, and complete field notes. 2. Variable Speed Bladder Pump • If sampling for organics, the pump body must be constructed of stainless steel and the valves and bladder must be Teflon. All tubing must be Teflon, polyethylene, or PP and any cabling must be sealed in Teflon, polyethylene or PP, or made of stainless steel. • After purging to a smooth even flow, reduce the flow rate. • When sampling for volatile organic compounds, reduce the flow rate to 100-200mL/minute, if possible. 3. Variable Speed Submersible Pump • The housing must be stainless steel. • If sampling for organics, the internal impellers, seals and gaskets must be constructed of stainless steel, Teflon, polyethylene or PP. The delivery tubing must be Teflon, polyethylene or PP; the electrical cord must be sealed in Teflon; any cabling must be sealed in Teflon or constructed of stainless steel. • After purging to a smooth even flow, reduce the flow rate. • When sampling for volatile organic compounds, reduce the flow rate to 100-200mL/minute, if possible. b.) Sampling with Bailers - A high degree of skill and coordination are necessary to collect representative samples with a bailer. 1. General Considerations • Minimize handling of bailer as much as possible. • Wear sampling gloves. • Remove bailer from protective wrapping just before use. • Attach a lanyard of appropriate material. • Use the lanyard to move and position the bailers. • Do not allow bailer or lanyard to touch the ground. • If bailer is certified precleaned, no rinsing is necessary. • If both a pump and a bailer are to be used to collect samples, rinse the exterior and interior of the bailer with sample water from the pump before removing the pump. • If the purge pump is not appropriate for collecting samples (e.g., non -inert components), rinse the bailer by collecting a single bailer of the groundwater to be sampled. • Discard the water appropriately. Rev 4-08 28 • Do not rinse the bailer if Oil and Grease samples are to be collected. 2. Bailing Technique • Collect all samples that are required to be collected with a pump before collecting samples with the bailer. • Raise and lower the bailer gently to minimize stirring up particulate matter in the well and the water column, which can increase sample turbidity. • Lower the bailer carefully into the well to a depth approximately a foot above the water column. When the bailer is in position, lower the bailer into the water column at a rate of 2 cm/sec until the desired depth is reached. • Do not lower the top of the bailer more than one foot below the top of the water table, so that water is removed from the top of the water column. • Allow time for the bailer to fill with aquifer water as it descends into the water column. • Do not allow the bailer to touch the bottom of the well or particulate matter will be incorporated into the sample. Carefully raise the bailer. Retrieve the bailer at the same rate of 2 cm/sec until the bottom of the bailer has cleared to top of the water column. • Lower the bailer to approximately the same depth each time. • Collect the sample. Install a device to control the flow from the bottom of the bailer and discard the first few inches of water. Fill the appropriate sample containers by allowing the sample to slowly flow down the side of the container. Discard the last few inches of water in the bailer. • Repeat steps for additional samples. • As a final step measure the DO, pH, temperature, turbidity and specific conductance after the final sample has been collected. Record all measurements and note the time that sampling was completed. c.) Sampling Low Permeability Aquifers or Wells that have Purged D 1. Collect the sample(s) after the well has been purged. Minimize the amount of water removed from the well by using the same pump to purge and collect the sample. If the well has purged dry, collect samples as soon as sufficient sample water is available. 2. Measure the five field parameters temperature, pH, specific conductance, dissolved oxygen and turbidity at the time of sample collection. 3. Advise the analytical laboratory and the client that the usual amount of sample for analysis may not be available. Rev 4-08 29 Appendix D - Collecting Samples from Wells with Plumbing in Place In -place plumbing is generally considered permanent equipment routinely used for purposes other than purging and sampling, such as for water supply. a.) Air Strippers or Remedial Systems - These types of systems are installed as remediation devices. Collect influent and effluent samples from air stripping units as described below. 1. Remove any tubing from the sampling port and flush for one to two minutes. 2. Remove all hoses, aerators and filters (if possible). 3. Open the spigot and purge sufficient volume to flush the spigot and lines and until the purging completion criteria have been met. 4. Reduce the flow rate to approximately 500 mUminute (a 1/8" stream) or approximately 0.1 gal/minute before collecting samples. 5. Follow procedures for collecting samples from water supply wells as outlined below. b.) Water Supply Wells — Water supply wells with in -place plumbing do not require equipment to be brought to the well to purge and sample. Water supply wells at UST facilities must be sampled for volatile organic compounds (VOCs) and semivolatile compounds (SVOCs). 1. Procedures for Sampling Water Supply Wells • Label sample containers prior to sample collection. • Prepare the storage and transport containers (ice chest, etc.; before taking any samples so each collected sample can be placed in a chilled environment immediately after collection. • You must choose the tap closest to the well, preferably at the wellhead. The tap must be before any holding or pressurization tank, water softener, ion exchange, disinfection process or before the water line enters the residence, office or building. If no tap fits the above conditions, a new tap that does must be installed. • The well pump must not be lubricated with oil, as that may contaminate the samples. • The sampling tap must be protected from exterior contamination associated with being too close to a sink bottom or to the ground. If the tap is too close to the ground for direct collection into the appropriate container, it is acceptable to use a smaller (clean) container to transfer the sample to a larger container. • Leaking taps that allow water to discharge from around the valve stem handle and down the outside of the faucet, or taps in which water tends to run up on the outside of the lip, are to be avoided as sampling locations. Rev 4-08 30 • Disconnect any hoses, filters, or aerators attached to the tap before sampling. • Do not sample from a tap close to a gas pump. The gas fumes could contaminate the sample. 2. Collecting Volatile Organic Samples • Equipment Needed: VOC sample vials [40 milliliters, glass, may contain 3 to 4 drops of hydrochloric acid (HCl) as preservative]; Disposable gloves and protective goggles; Ice chest/cooler; Ice; Packing materials (sealable plastic bags, bubble wrap, etc.); and Lab forms. • Sampling Procedure: Run water from the well for at least 15 minutes. If the well is deep, run water longer (purging three well volumes is best). If tap or spigot is located directly before a holding tank, open a tap after the holding tank to prevent any backflow into the tap where you will take your sample. This will ensure that the water you collect is "fresh" from the well and not ftom the holding tank. After running the water for at least 15 minutes, reduce the flow of water. The flow should be reduced to a trickle but not so slow that it begins to drip. A smooth flow of water will make collection easier and more accurate. Remove the cap of a VOC vial and hold the vial under the stream of water to fill it. Be careful not to spill any acid that is in the vial. For best results use a low flow of water and angle the vial slightly so that the water runs down the inside of the vial. This will help keep the sample ftom being agitated, aerated or splashed out of the vial. It will also increase the accuracy of the sample. As the vial fills and is almost full, turn the vial until it is straight up and down so the water won't spill out. Fill the vial until the water is just about to spill over the lip of the vial. The surface of the water sample should become mounded. It is a good idea not to overfill the vial, especially if an acid preservative is present in the vial. Carefully replace and screw the cap onto the vial. Some water may overflow as the cap is put on. After the cap is secure, turn the vial upside down and gently tap the vial to see if any bubbles are present. If bubbles are present in the vial, remove the cap, add more water and check again to see if bubbles are present. Repeat as necessary. After two samples without bubbles have been collected, the samples should be labeled and prepared for shipment. Store samples at 4° C. Rev 4-08 31 3. Collecting Extractable Organic and/or Metals Samples • Equipment Needed: SVOC sample bottle [1 liter, amber glass] and/or Metals sample bottle [0.5 liter, polyethylene or glass, 5 milliliters of nitric acid (HNO3) preservative]; Disposable gloves and protective goggles; Ice Chest/Cooler; Ice; Packing materials (sealable plastic bags, bubble wrap, etc.); and Lab forms. • Sampling Procedure: Run water from the well for at least 15 minutes. If the well is deep, run the water longer (purging three well volumes is best). If tap or spigot is located directly before a holding tank, open a tap after the holding tank to prevent any backflow into the tap where you will take your sample. This will ensure that the water you collect is "fresh" from the well and not from the holding tank. After running the water for at least 15 minutes, reduce the flow. Low water flow makes collection easier and more accurate. Remove the cap of a SVOC or metals bottle and hold it under the stream of water to fill it. The bottle does not have to be completely filled (i.e., you can leave an inch or so of headspace in the bottle). After filling, screw on the cap, label the bottle and prepare for shipment. Store samples at 4° C. Rev 4-08 32 Appendix E - Collecting Surface Water Samples The following topics include 1.) acceptable equipment selection and equipment construction materials and 2.) standard grab, depth -specific and depth-composited surface water sampling techniques. Facilities which contain or border small rivers, streams or branches should include surface water sampling as part of the monitoring program for each sampling event. A simple procedure for selecting surface water monitoring sites is to locate a point on a stream where drainage leaves the site. This provides detection of contamination through, and possibly downstream of, site via discharge of surface waters. The sampling points selected should be downstream from any waste areas. An upstream sample should be obtained in order to determine water quality upstream of the influence of the site. a.) General Cautions 1. When using watercraft take samples near the bow away and upwind from any gasoline outboard engine. Orient watercraft so that bow is positioned in the upstream direction. 2. When wading, collect samples upstream from the body. Avoid disturbing sediments in the immediate area of sample collection. 3. Collect water samples prior to taking sediment samples when obtaining both from the same area (site). 4. Unless dictated by permit, program or order, sampling at or near man- made structures (e.g., dams, weirs or bridges) may not provide representative data because of unnatural flow patterns. 5. Collect surface water samples from downstream towards upstream. b.) Equipment and Supplies - Select equipment based on the analytes of interest, specific use, and availability. c.) Surface Water Sampling Techniques - Adhere to all general protocols applicable to aqueous sampling when following the surface water sampling procedures addressed below. 1. Manual Sampling: Use manual sampling for collecting grab samples for immediate in -situ field analyses. Use manual sampling in lieu of automatic equipment over extended periods of time for composite sampling, especially when it is necessary to observe and/or note unusual conditions. • Surface Grab Samples - Do not use sample containers containing premeasured amounts of preservatives to collect grab samples. If the sample matrix is homogeneous, then the grab method is a simple and effective technique for collection purposes. If homogeneity is not apparent, based on flow or vertical variations (and should never be assumed), then use other collection protocols. Where practical, use the actual sample container submitted to the laboratory for collecting samples to be analyzed for oil and grease, volatile organic compounds (VOCs), and microbiological samples. This procedure eliminates the possibility of contaminating the sample with an intermediate collection container. The use of Rev 4-08 33 unpreserved sample containers as direct grab samplers is encouraged since the same container can be submitted for laboratory analysis after appropriate preservation. This procedure reduces sample handling and eliminates potential contamination from other sources (e.g., additional sampling equipment, environment, etc.). 1. Grab directly into sample container. 2. Slowly submerge the container, opening neck first, into the water. 3. Invert the bottle so the neck is upright and pointing towards the direction of water flow (if applicable). Allow water to run slowly into the container until filled. 4. Return the filled container quickly to the surface. 5. Pour out a few mL of sample away from and downstream of the sampling location. This procedure allows for the addition of preservatives and sample expansion. Do not use this step for volatile organics or other analytes where headspace is not allowed in the sample container. 6. Add preservatives, securely cap container, label, and complete field notes. If sample containers are attached to a pole via a clamp, submerge the container and follow steps 3 — 5 but omit steps I and 2. • Sampling with an Intermediate Vessel or Container: If the sample cannot be collected directly into the sample container to be submitted to the laboratory, or if the laboratory provides prepreserved sample containers, use an unpreserved sample container or an intermediate vessel (e.g., beakers, buckets or dippers) to obtain the sample. These vessels must be constructed appropriately, including any poles or extension arms used to access the sample location. I. Rinse the intermediate vessel with ample amounts of site water prior to collecting the first sample. 2. Collect the sample as outlined above using the intermediate vessel. 3. Use pole mounted containers of appropriate construction to sample at distances away from shore, boat, etc. Follow the protocols above to collect samples. • Peristaltic Pump and Tubing: The most portable pump for this technique is a 12 volt peristaltic pump. Use appropriately precleaned, silastic tubing in the pump head and attach polyethylene, Tygon, etc. tubing to the pump. This technique is not acceptable for Oil and Grease, EPH, VPH or VOCs. Extractable organics can be collected through the pump if flexible interior -wall Teflon, polyethylene or PP tubing is used in the pump head or if used with the organic trap setup. Rev 4-08 34 1. Lower appropriately precleaned tubing to a depth of 6 — 12 inches below water surface, where possible. 2. Pump 3 — 5 tube volumes through the system to acclimate the tubing before collecting the first sample. 3. Fill individual sample bottles via the discharge tubing. Be careful not to remove the inlet tubing from the water. 4. Add preservatives, securely cap container, label, and complete field notes. Mid -Depth Grab Samples: Mid -depth samples or samples taken at a specific depth can approximate the conditions throughout the entire water column. The equipment that may be used for this type of sampling consists of the following depth -specific sampling devices: Kemmerer, Niskin, Van Dorn type, etc. You may also use pumps with tubing or double check -valve bailers. Certain construction material details may preclude its use for certain analytes. Many Kemmerer samplers are constructed of plastic and rubber that preclude their use for all volatile and extractable organic sampling. Some newer devices are constructed of stainless steel or are all Teflon or Teflon -coated. These are acceptable for all analyte groups without restriction. 1. Measure the water column to determine maximum depth and sampling depth prior to lowering the sampling device. 2. Mark the line attached to the sampler with depth increments so that the sampling depth can be accurately recorded. 3. Lower the sampler slowly to the appropriate sampling depth, taking care not to disturb the sediments. 4. At the desired depth, send the messenger weight down to trip the closure mechanism. 5. Retrieve the sampler slowly. 6. Rinse the sampling device with ample amounts of site water prior to collecting the first sample. Discard rinsate away from and downstream of the sampling location. 7. Fill the individual sample bottles via the discharge tube. Double Check -Valve Bailers: Collect samples using double check - valve bailers if the data requirements do not necessitate a sample from a strictly discrete interval of the water column. Bailers with an upper and lower check -valve can be lowered through the water column. Water will continually be displaced through the bailer until the desired depth is reached, at which point the bailer is retrieved. Sampling with this type of bailer must follow the same protocols outlined above, except that a messenger weight is not applicable. Although not designed specifically for this kind of sampling, a bailer is acceptable when a mid -depth sample is required Rev 4-08 35 1. As the bailer is dropped through the water column, water is displaced through the body of the bailer. The degree of displacement depends upon the check -valve ball movement to allow water to flow freely through the bailer body. 2. Slowly lower the bailer to the appropriate depth. Upon retrieval, the two check valves seat, preventing water from escaping or entering the bailer. 3. Rinse the sampling device with ample amounts of site water prior to collecting the first sample. 4. Fill the individual sample bottles via the discharge tube. Sample bottles must be handled as described above. Peristaltic Pump and Tubing: The most portable pump for this technique is a 12 volt peristaltic pump. Use appropriately precleaned, silastic tubing in the pump head and attach HDPE, Tygon, etc. tubing to the pump. This technique is not acceptable for Oil and Grease, EPH, VPH or VOCs. Extractable organics can be collected through the pump if flexible interior -wall Teflon, polyethylene or PP tubing is used in the pump head, or if used with an organic trap setup. 1. Measure the water column to determine the maximum depth and the sampling depth. 2. Tubing will need to be tied to a stiff pole or be weighted down so the tubing placement will be secure. Do not use a lead weight. Any dense, non -contaminating, non - interfering material will work (brick, stainless steel weight, etc.). Tie the weight with a lanyard (braided or monofilament nylon, etc.) so that it is located below the inlet of the tubing. 3. Turn the pump on and allow several tubing volumes of water to be discharged before collecting the first sample. 4. Fill the individual sample bottles via the discharge tube. Sample bottles must be handled as described above. Rev 4-08 36 APPENDIX C Geoprobe® Pneumatic Slug Test Kit Installation and Operation Instructions Instructional Bulletin No. MK3195 Geoprobe° Pneumatic Slug Test Kit (GW1600) Installation and Operation Instructions for USB System Instructional Bulletin No. MK3195 Prepared: February, 2014 Acquisition Module Transducer, C,� Cable USB cable Manifold Assembly i Pressure Transducer Screen Sheath \Screen Interval Expendable Point Figure A: Typical field setup with SP15/16 groundwater sampler Laptop Computer cT d e f b a 9 Figure B: Manifold Assembly with: (a) inlet valve (b) regulator (c) vacuum gauge (d) pressure gauge (e) transducer port (f) release valve (g) 1.25" rod adapter Operating the Pneumatic Slug Test Kit 1.0 Objective The Geoprobe° Pneumatic Slug Test Kit is used in conjunction with direct push (DP) groundwater sampling tools (SP16, SP22, etc.) or monitoring wells to perform slug tests. The slug test responses are modeled and used to determine the hydraulic conductivity (K) of the screened aquifer (Butler 1997, Butler and Garnett 2000, Butler et al. 2002, McCall et al. 2002). This bulletin identifies the tools and basic techniques required to successfully operate the Pneumatic Slug Test Kit. The DP groundwater samplers or wells (Geoprobe° 2006a,b,c, 2009a,2010) may be installed at multiple depths (profiling) and locations across a site to define the spatial variations in K and contaminant distribution (McCall et al. 2002, 2006, 2009 ). The procedures outlined below conform to the ASTM Standard Practice D 7242 (ASTM 2013a) for performing pneumatic slug tests with DP methods. 2.0 Required Equipment All the components of the Pneumatic Slug Test kit are provided in a carrying case for ease of transportation. The major components of the kit (Figure 1) include the pneumatic head assembly, pressure transducer, data logger and accessories needed to complete the slug testing process. When slug testing PVC wells additional PVC adapters will be required (214039 for sch. 40 PVC wells <_1-inch, 207304 for sch. 40, 2-inch PVC wells). Pneumatic slug testing of larger diameter wells may be performed with custom adapters. 3.0 Preparation Before Slug Testing The groundwater sampling tools (Figure A, cover; Geoprobe° 2006, 2010, ASTM 2013b) or monitoring wells (Geoprobe° 2006b, 2006c, 2009a, ASTM 2013c) must be installed properly before slug testing can be performed. For both wells and DP groundwater samplers O-rings (or equivalent) must be used on each casing or rod joint respectively, to provide for an airtight system needed for pneumatic testing. Once installed the groundwater samplers or wells must be adequately developed (ASTM 2013d, Geoprobe° 2002a) to obtain representative slug test results. When installed in sandy formations many groundwater samplers and wells may be adequately developed (Figure 2) with a simple check valve (GW4210, GW4220 or GW4230) to assure that representative slug tests and K-values are obtained. Water quality sampling usually requires more stringent methods for well development (Geoprobe® 2002a, ASTM 2013d). For short screen groundwater samplers and wells purging as little as 1 to S gallons (4 to 20 liters) is often sufficient for development. Be sure to document well construction parameters (screen length, boring diameter, casing radius, etc.) so that K maybe correctly calculated. Information about aquifer thickness and whether the aquifer is confined or unconfined will need to be determined to enable correct K calculation. In order for pneumatic slug tests to be successfully performed the static water level must be above the screened interval of the well, prior to and during the pneumatic slug test. If this is not the case mechanical slug tests may be performed on the well using the transducer, acquisition module and software included with the kit. A mechanical slug is not included with the GW1600 kit. Installation/Operation Instructions 2 Pneumatic Slug Test Kit Pneumatic Head Asm 203153 15 psi Transducer Asm, 100ft (30.5m) 216870 11� Test Jig 203898 Hand Pump 600711 . � Hand Pump Hose Asm 211224 USB Cable (15ft) 104158 o 0 0 Pressure Hyd. Cond. Acquisition 4� Regulator Module GW2610 Power Inverter 102761 214040 107479 O 1.25 pin x 1.5 box 202790 1.25 pin x 1 FNPT 211289 Leak j -- j ❑ Test =� Fluid 600149 Foot Pump 102763 Foot Pump Hose Asm 203154 Pressure Gauge 102760 Vacuum Gauge 104501 12V Socket 2( Figure 1: Major components of the GW1600 Pneumatic Slug Test Kit (not to scale). Installation/Operation Instructions 3 Pneumatic Slug Test Kit 4.0 Installation of the Pneumatic Head and Transducer The pneumatic head is installed on the probe rod using the appropriate adapter (Figure 3). When slug testing PVC wells additional PVC adapters will be required to attach the pneumatic head to the well casing (Geoprobe° 2002b). Use appropriate 0-rings, plumbers tape or bushing to obtain an airtight seal between the pneumatic head and probe rod or PVC casing. When the pneumatic head is installed unthread the knurled fitting from the transducer port and remove the copper washer and split bushing (Figure 4). Replace the copper washer and knurled fitting on top of the transducer port. Next lower the transducer down through the well until it is submerged about 6 feet (2 m) below the static water level. Allow the transducer to cool to the ambient groundwater temperature (usually 3 to 5 minutes) before zeroing or slug testing is started. Reinstall the split bushing (Figure 4) to complete the seal after the transducer is zeroed at atmospheric pressure (see below) and installed at the desired depth. Please review the following notes to be sure you obtain valid data and to minimize potential damage to kit components: NOTE: The inside diameter of the release valve used to initiate the test should be of equal or greater ID than the well casing to assure free flow of air from the well and that no interference or noise occurs to degrade data quality. The release valve on the pneumatic head has an ID of 1.0 inches (25.4 mm). A pneumatic head adapter (207304) is available for 1.5-inch and 2-inch (38 and 50mm) PVC wells. Custom adapters can be fabricated for larger wells. CAUTION: The transducer is delicate. Do not step on or strike the transducer as it may be damaged. Do not submerge the transducer more than 15 ft (4.5 m) below the static water level. Do not place the transducer in water with high concentrations of solvents or where free product is present as it can be damaged. CAUTION: The transducer is vented by a small tube running through the cable. Do not kink the transducer cable as the vent tube may be pinched. This can result in an inoperable transducer. NOTE: Keep the transducer cable out of direct sunlight before and while tests are being performed. Sunlight will warm the air in the vent tube and may cause noticeable drift of the baseline (Cain et al., 2004). This can interfere with modeling of the slug test response and accurate calculation of K. Foam pipe insulation may be placed around exposed sections of transducer cable to prevent solar heating and baseline drift on sunny days. Keep excess loops of transducer cable in the shade, (e.g. inside a box or sample cooler). 4 b I. V Figure 2: Development of an SP16 groundwater sampler with a check valve (214061, 214062 or similar) by surging and purging. This may be conducted manually or the 12V Mechanical Actuator (214106) may be used. Older wells may require redevelopment to obtain accurate slug test results. Installation/Operation Instructions 4 Pneumatic Slug Test Kit Pneumatic Head Asm. with 1.25" Pneumatic Head Asm. with 1.25" rod adapter installed rod adapter removed 1.25" pin X 1" NPT X 3" nipple 1.5" box 106472 202790 —+ 1.25" pin X 1.25" Probe rod 1" FNPT pin up for SP15 or PN 46986 similar 1.5" Probe rod 1.25" Probe rod** pin down for SP22 (*) 0-ring 1.25" rod 213771 (+) 0-ring 1.5" rod 202695 Figure 3: Installation of the pneumatic head on different probe rod/groundwater sampler configurations. When slug testing PVC wells additional PVC adapters will be required to attach the pneumatic head to the well casing (Geoprobe° 2002b). ** Because of radius change in ID of 1.25" light weight rods they cannot be used for slug testing. Figure 4: Transducer seal assembly showing the knurled cap, copper washer and split bushing on the transducer cable after the transducer is lowered to depth. USB Cable 104158 Figure 5: The 15ft USB cable is used to attach the data acquisition module (GW2610) to the laptop computer for signal transmission. The USB cable also provides power from the laptop computer to operate the acquisition module and the transducer downhole. If needed the 12V power inverter (Figure 1, 107479) included with the kit may be attached to the Power Point of a Geoprobe° unit or vehicle to recharge the computer battery. Installation/Operation Instructions 5 Pneumatic Slug Test Kit 5.0 Acquisition Software and Acquisition Module The Slug Test Acquisition software (V 3.0) is provided on a USB drive with the kit. Install the drive in one of the USB ports of the computer and follow the onscreen instructions for installation. This usually requires less than 2 minutes. A folder titled "dirim95" is created on the computer hard drive to store the acquisition software. The data files (*.dat) generated by slug testing are saved in a subfolder titled "logfiles" for later retrieval, viewing and modeling. The USB cable (Figure 5, above) is used to connect the acquisition module (GW2610, Figure 6) to the computer for signal transmission. The USB cable also supplies power to the acquisition module and transducer. The power inverter (107479) supplied with the kit may be plugged into a vehicle or Geoprobe® unit power point to provide the electrical current required to operate the computer and slug test system. The transducer is attached to the sensor port on the acquisition module (Figure 6). The acquisition module converts the analog signal from the transducer to digital signal that is received by the computer for live -time display and storage in data files. 6.0 Initiate Software: Zero Transducer When the software is started a blank graphing window opens showing the CONNECT icon in the upper right corner (Figure 7). Click on the CONNECT icon and the software will search the active com ports on the computer and locate the port the Acquisition Module is connected to and make the connection. Once the connection is made the ZERO TRANSDUCER window opens (Figure 8). Allow the transducer to cool to ambient groundwater temperature in the well for at least 3 to 5 minutes. Then gently raise the transducer above the water level (voltage readout drops and then stabilizes) and click on the CONTINUE icon and the transducer will be zeroed. Some fluctuation in the last couple of digits on the transducer readout is expected while zeroing, especially for higher frequency settings (e.g. 10Hz). Zeroing the transducer at atmospheric pressure lets the operator know how deep the transducer is below the water level in the well prior to testing and between tests. If you want to keep the previous zero level you can choose to BYPASS the zero function (recommend re -zeroing after moving to a new location). Now lower the transducer below the water level to the desired depth for slug testing. Usually the transducer is set at about 6 ft (2 m) below the water level for slug testing. Initial head values of greater than 5 ft (1.5 m) are usually not required for slug testing and larger head values may cause some errors of measurement in fast or oscillatory recovering wells. Smaller initial head values are usually preferred. Installation/Operation Instructions 6 Pneumatic Slug Test Kit 0 GEOPROBE(D SLUG TEST V3.0 BUILD 13169 E3 SLUG GrapF -ILE 1_ _ CONNECT •9 NOT CON N ECLED 0.8 - 0.7- 00 tt LOG FREQ os- CONNECT o.a- NOT SAVING OMIT LOG FREQ NEXT 0- CONNECT BAR -0.1- B -0.2- O0N" FNOT SAVING FT of H EAD -0.3 - 0 -0.a- LOG FREQ NEJ(T s H� mm of HEAD -0.5- -0.6- O F 07 NOT SAVING TIME (SEC) -0.8- NE]LT 0.00 -0.s- 1 1 105 11 1.15 12 1.JS 1.3 1.35 1.4 1.45 19 1.55 1.6 1.65 1.75 1.8 1.85 1.9 1.95 2 TIME [SEC] Figure 7: Click on the CONNECT icon and the software will search for the com port where the Acquisition Module is connected with the USB cable. The CONNECTING icon flashes red while searching for the correct com port. The icon changes to green CONNECTED when the connection to the correct com port is made. This search and connection usually requires less than a minute. 0 ZERO TRANSDUCER . [—=:]= r File Edit Operate Tools Window Heir TRANDUCER ZERO 00823224 VOLTS CONTINUE BYPA55 Figure 8: Allow the transducer to cool to ambient groundwater temperature in the well. Then raise the transducer above the water level and click on CONTINUE to zero the transducer at atmospheric pressure. You can select BYPASS if you prefer to keep the previous zero value. Installation/Operation Instructions 7 Pneumatic Slug Test Kit Once the transducer is zeroed the setup information window opens (Figure 9). Look at the metallic transducer body to see whether it is a 10 psi or 15 psi model and select the correct value under sensor type. Select your units preference. The units are presented as feet of head in English and as millimeters of head in metric. Choose the desired logging frequency based on the speed and type of recovery expected in the well. For wells that recover quickly (< 60 sec) or exhibit an oscillatory response a frequency of at least 5 Hertz (Hz) is recommended. For wells that require several minutes or longer to recover a frequency of 1 Hz or 2 Hz should be sufficient. The MONITOR setting is useful for leak testing and initial evaluation of a well's response before saving data. Under this option no data is saved and you can simply run a test or two to observe the well response and select the best log frequency. To run a slug test or series of slug tests and save the data to a file select the LOG option and click on the continue icon. The FILE NAME window opens (Figure 10) where a filename can be entered. The transducer serial number may be edited in this window. Figure 9: Select the appropriate setting under each heading and click on the continue icon to proceed. Review text for details. l- SETUP INFO.vi File Edit Operate Tools o FEE® Window Help SENSOR TYPE UNITS SELECTION 10 PSI ENGLISH 0 15 PSI METRIC TEST LOAD LOG SELECTION LOG FREQUENCY MONITOR 1 Hz v LOG 2 Hz a 5 Hz CONTiNLIE 10 HZ 0 SCrEINFORMATION E3 9. -TAB> between entries. 2. When finished,<TAB> to'OK' and press <ENTER>. FILE NAME: Ktest01 TRANSDUCER NUMBER: 1237 CHANGE SENSOR NUMBER CONTINUE Figure 10: If the LOG option is selected in the setup window then the FILENAME window opens. Enter an appropriate file name. Click on CHANGE SENSOR NUMBER option to update the sensor serial number. The serial number is located on the metal body of the transducer. Tracking the serial number lets the operator know which transducer was used to run the slug tests. This can be useful quality control information. Once you click on the continue icon at the setup info page or filename page the slug test graph window opens (Figure 11) where head pressure is plotted versus time. When the graph window first opens the auto scale function magnifies the baseline and you may see what appears to be large noise spikes. Lowering the transducer just into the water will auto -adjust the vertical scale so that the apparent noise is reduced. When you are prepared to start saving data click on the NOT SAVING icon (it will change to SAVING) and data will be sent to the filename previously specified. Installation/Operation Instructions 8 Pneumatic Slug Test Kit M. GEOPROBE@ SLUG TEST V3.0 BUILD13169 SLUG Graph 5.80 5.70 5.60 5.50 5.40 5.30 5.20 5.10 5.00 4.90 4.80 = 4.70 4.60 4.50 4.40 CdNNECT A M LOG FREQ 5 Hz NOT SAVING ^ 5AVING NEXT Baseline Magnified BAR 0.0127899 FT of HEAD B 10.427899 mm of HEAD 42{}- ,,°,.,.!.A v aknnn.ni i L A 130.421 410- IIME [SEC] 4100- 390- 42.80 3.80 0.0 5A 16.6 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.3 15 PSI TIME [SEC] Figure 11: Once the setup info and file name are entered the slug test graph window opens where pressure head is plotted versus time. When the graph first opens the baseline may be magnified due to auto scaling. To start saving data to the file simply click on the NOT SAVING icon. It will change to a green SAVING icon to indicate that data is being saved to file. Air pressurization peaks (A) will be observed on screen when air is added to pressurize the well head. After the system pressure returns to equilibrium the release valve is opened on the pneumatic head to initiate the slug test (B). After slug testing is completed end the file by clicking on the NEXT icon. When slug testing is complete at the well click on the NEXT icon to close the file. When the file is closed a popup window will open giving you the option to exit the program or continue (Figure 12). If continue is selected the program loops back to the Setup info window (Figure 9) so you can enter the parameters for the next slug test. EXIT OR CONTINUE: CONTINUE Figure 12: Selecting EXIT will take you out of the program. Selecting CONTINUE will loop you back to the setup information menu to enter data for the next slug test file. NOTE: The SAVING icon must be present in the graphing window for data to be saved to the named file. Installation/Operation Instructions 9 Pneumatic Slug Test Kit 7.0 Leak Testing To verify that rod or casing joints and the pneumatic head are air tight a leak test is performed (Figure 13). Insert the pressure gauge in the upright quick connect and attach the hand pump (or other air pressure source*) to the horizontal quick connect. If a higher pressure air source is used place the pressure regulator** assembly (102761) between the source and the inlet valve to prevent damage to the gauge and jetting air into the formation. Pressurize the well head to about 20 inches Figure 13: Setup for leak test and rising head (50 cm) of water pressure (this is < 1 psi). This will tests with the pressure gauge and hand require several pumps on the hand pump and will pump. The gauges are graduated in inches result in increased pressure readout on the computer and centimeters of water pressure (outer screen (Figure 11-A) that will return to the original and inner marks respectively). Close the inlet valve after pressurizing. baseline pressure. The total air pressure + water pressure over the transducer will return to equilibrium with the formation hydrostatic pressure. If excess air pressure is applied the water level will drop below the transducer and the stabilized pressure observed onscreen will exceed the ambient water pressure observed by the transducer. Reduce excess air pressure so that valuable early time response data is not missed when the test is started. Observe the pressure gauge for leak testing. Air pressure observed on the gauge (and computer screen, Figure 11-A) will bounce up and down as air is pumped into the well head and water flows out of the screen. Once pumping is stopped the air pressure should stabilize and the gauge readout indicates how far (inches/centimeters) the water level has been lowered in the well. Add more air if a larger initial head (Ho) displacement is desired. If the air pressure readout on the gauge continues to fall and returns to zero there is a system leak. (Remember, lower K formations will recover slowly from pressurization.) Use the leak check fluid (600149), included with the kit and apply it to exposed joints and fittings, watch for small bubbles to appear at leaks. Tighten any leaky fittings until an air tight system is obtained. Once the system is air tight slug tests may be conducted. Leaks may occur down -hole at probe rod joints or well casing joints. Use a pipe wrench to snug the probe rod tool string and seal joints (O-rings or equivalent must be used on all rod and casing joints). If down -hole leaks cannot be sealed the pressure regulator and air supply may be used to stabilize slow leaks so that a successful slug test may be obtained. Install the regulator at the inlet valve and use the air supply to provide a steady air flow to offset small air leaks downhole. *NOTE: An electric pressure/vacuum pump may be substituted for the manual pump for testing larger diameter/deeper wells and piezometers. Small 12V pumps (e.g. Cole Parmer model EW-79200-40) are convenient for operation in the field. Compressed gas cylinders may be used (e.g. air or NA but a regulator to reduce the pressure to <10 psi will be required. Handling and transportation of compressed gas cylinders requires special safety precautions. Review requirements with your supplier to assure compliance with DOT and local regulations. **NOTE: the pressure regulator is only a 10 psi unit, applying excess pressure will damage the regulator. Installation/Operation Instructions 10 Pneumatic Slug Test Kit 8.0 Performing Slug Tests Once leak testing is completed, the transducer zeroed and the file has been named (Sections 5, 6 & 7) you are ready to perform slug tests. Be sure to click on the NOT SAVING icon to begin SAVING so the data is saved to file (Figure 11). The pressure required to perform a successful slug test is relatively low, not more than 1 to 2 psi (-7 to 14 kPa) maximum. Higher pressures and larger initial head values are generally not required to obtain a representative slug test as the calculated K value is independent of initial head magnitude (Butler 1997). (Larger Ho values may be preferred when unsaturated filter packs are present.) For underdamped (oscillatory) responses larger Ho values may actually result in attenuation of the test response and an under -estimation of K. Usually, Ho values between about 5 — 40 inches (-10 —100 cm) of water pressure are used for pneumatic slug tests. For slow recovering overdamped responses (e.g. 15+ minutes) it may be useful to allow the test to recover only to about 90% before starting pressurization or evacuation for the next test, note this in the log book. For moderate to fast overdamped recoveries and all under - damped tests it is best to allow the formation to fully recover between tests. This is necessary so that accurate modeling and calculations can be obtained for these shorter duration tests. To perform rising head tests install the pressure gauge on the pneumatic head and set the valve on the hand pump (600711) to pressure. For falling head tests install the vacuum gauge (Figure 13) on the pneumatic head and set the valve to vacuum on the hand pump. Close the release valve (Figure B, cover) on the pneumatic head and pressurize or evacuate the well head to the desired Ho value. Close the inlet valve (Figure B). Allow the pressure to stabilize on the gauge and computer screen. Then quickly open the release valve to initiate the slug test. The slug test response is observed onscreen in real time (Figure 14). Note the difference in the response of the Figure 13: Use the vacuum gauge to perform falling head tests or install the pressure gauge to conduct rising head rising and falling head tests. tests and for leak testing. Basic field quality control may be performed by conducting repeat tests with the same initial head in the same data file (Figure 15). When this is done the operator can visually compare the peak height, symmetry, and recovery time of the repeat tests. If repeat tests with the same Ho value show noticeable differences in peak height, symmetry or recovery time it is an indication that further development of the well is required. Additional quality control may be obtained by performing repeat rising or falling head tests with differing Ho values (e.g. 10, 20 and 30 inches of water pressure). Later, these test responses can be normalized and overlaid to verify that the slug test responses were linear over the range of head values used to perform the slug tests. This also provides confidence that the results of the tests conform with the slug test model requirements (Butler 1997). Slug test procedures reviewed in this bulletin meet or exceed ASTM Standard Practice requirements (ASTM 2007a). Installation/Operation Instructions 11 Pneumatic Slug Test Kit 6.60- 6.40- 6.20- 6.00- D s.ao- A 5.60- 5.40- E 5.20- 5.00- C 4.80- 4.60- B 4.40- 4.20- 4.00- 3.80 0.0 1o,0 20.0 30,0 40.0 50.0 60,0 70.0 80.0 90,0 100.0 110,0 120.0 130,0 140,0 150.0 160,0 TIME (SEC) Figure 15: Repeat of overdamped slug tests with approximately the same initial head value. These tests can be used for basic field QC. The Ho values were 20, 20 and 19 inches of water respectively. The similarity of peak height, symmetry and recovery time indicates that good quality tests were obtained. If noticeable variations occur between repeat tests further well development may be required. 9.0 Document Test Parameters Figure 14: Performing a rising head test and then a falling head test. A: air pressurization peaks. B: rising head test. C: evacuation peaks. D: falling head test. E: stable baseline is about 5.46 ft (163 cm) for these tests, i.e. the static water level is that distance above the transducer sensor. These are examples of underdamped (oscillatory) tests. ;Ire- Sense)SP22 ProFlling)HP03 slug test data\HP3653dal 5 4- 5,3- 5,2- 5d- 0 5.0- 41- 4,]- 9,6- ,- , 4 4,3- 4,2- 4,0- 58 68.8 88,8 51 m 51 cm 4 288,8 .5 m 358,8 188.0 128,0 198,8 168.8 188,8 208.8 T— 228,8 (Sec) 248.0 268,0 388.8 328,8 The field team should document how the slug tests were performed in the field so that modeling and calculations can be performed correctly once the field work is completed. The slug test field data can be documented in a simple table or form (Figure 16). Field information about the well construction geometry (Figure 17) and aquifer type (confined/unconfined) also will be required to complete modeling of the slug test data and calculation of the formation K. Site: ABC Plating Corp Well No: SP22A-53ft Operator: Stephanie Jones Date: Oct. 10, 2010 File: HP3A53 FileTime (sec) Ho (in) Rise Fall Notes 120 20 R overdamped 220 20 R Slow leak 320 40 R Leak corrected 450 10 R No leak 550 20 R 50 30 F New File = HP3653 160 30 F overdamped 280 10 F 410 20 F No leaks Figure 16: Example table for documentation of slug testing information in the field. See page 14. Installation/Operation Instructions 12 Pneumatic Slug Test Kit Geoprobe° Slug Test Field Information Form for Well Construction/Water Sampler Installation Proi. Name: Well #: Date Operator: File #s: rt = TD = Rc = SWL= Lw = Ts = h= Le = Ls = Rb= �Rc= Impermeable Layer Figure 17: Field form for use in documenting well or groundwater sampler construction that is slug tested. This data required so K value can be calculated. Copy for field use. See below for parameter definitions. Installation/Operation Instructions 13 Pneumatic Slug Test Kit Parameter definitions for Figure 17: Le = effective screen length Lw = length of water column Rb = borehole/filter pack radius rt = radius of transducer cable SWL = static water level h = saturated thickness of aquifer Ls = physical screen length Rs = screen radius Rc = casing radius Ts = depth transducer submerged TD = total well depth Ho = initial head change for slug test In wells < 2 inch/50mm diameter the casing radius is corrected for the diameter of the transducer cable in the Slug Test Analysis software (see below). The corrected casing radius (Rcc) is calculated as follows: Rcc = (Rcz — rtz)112 (after Butler et al. 2002) 10.0 Modeling and Calculation of K Geoprobe° provides the user friendly Slug Test Analysis software package (GW1650 (214042): Geoprobe 2009b) with the kit. This is for modeling (Figure 18) and calculation of the formation hydraulic conductivity (K) with the kit. This package includes the Bouwer and Rice model (Bouwer and Rice, 1976) and the Hvorslev model (Hvorslev, 1951) for calculation of K. The software provides variants of these two basic models for confined or unconfined aquifers, partially or fully penetrating wells, and over or underdamped aquifer responses. A correction for oscillatory slug test responses in small -diameter wells (Butler 2002) also is included in the Geoprobe° analysis software. Figure 18: Modeling an underdamped slug test response with the Geoprobe® Slug Test Analysis Software package (GW1650).The software provides for input of well construction parameters, modeling and calculation of K with graphical print outs. The analysis software is included with the slug test kit. Installation/Operation Instructions 14 Pneumatic Slug Test Kit 11.0 References American Society of Standards and Methods (ASTM), 2013a. D 7242 Standard Practice for Field Pneumatic Slug (Instantaneous Change in Head) Tests to Determine Hydraulic Properties of Aquifers with Direct Push Ground Water Samplers. ASTM International, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA. www.astm.org ASTM, 2013b. D 6001 Standard Guide for Direct -Push Ground Water Sampling for Environmental Site Characterization. ASTM International, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA. www.astm.org ASTM, 2013c. D 6725 Standard Practice for Direct Push Installation of Prepacked Screen Monitoring Wells in Unconsolidated Aquifers. ASTM International, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA. www.astm.org ASTM, 2013d. D 5521 Standard Guide for Development of Ground -Water Monitoring Wells in Granular Aquifers. ASTM International, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA. www.astm.org Bouwer, Herman, and R.C. Rice. 1976. A Slug Test for Determining Hydraulic Conductivity of Unconfined Aquifers with Completely or Partially Penetrating Wells. Water Resources Res. Vol. 12, pp 423-428. Butler, James J., Jr. 1997. The Design, Performance, and Analysis of Slug Tests. CRC Press, Boca Raton, FL. Butler, James J., Jr. and Elizabeth J. Garnett, 2000. Simple Procedures for Analysis of Slug Tests in Formations of High Hydraulic Conductivity using Spreadsheet and Scientific Graphics Software. Kansas Geological Survey Open -file Report 2000-40. Butler, James J., Jr., John M. Healey, G. Wesley McCall, Elizabeth J. Garnett and Steven P. Loheide II, 2002. Hydraulic Tests with Direct Push Equipment. Ground Water, Vol. 40, No.1, pages 25 - 36. Butler, James J. Jr., 2002. A Simple Correction for Slug Tests in Small -Diameter Wells. Ground Water Vol. 40, No. 3, pages 303- 307. Cain, Samuel F., Gregory A. Davis, Steven P. Loheide and James J. Butler, Jr., 2004. Noise in Pressure Transducer Readings Produced by Variations in Solar Radiation. Ground Water Vol. 42, No. 6, pages 939-944. Nov. -Dec. Geoprobe® 2002a. Groundwater Quality and Turbidity vs. Low Flow. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2002b. Geoprobe® GW1601K PVC Adapter Kit. Instruction Bulletin No. 21376. September. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2006a. Geoprobe® Screen Point 16 Groundwater Sampler, Standard Operating Procedure. Technical Bulletin No. MK3142. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2006b. Geoprobe° 0.5-in. x 1.4-in. OD and 0.75-in. x 1.4-in. OD Prepacked Screen Monitoring Wells, Standard Operating Procedure. Technical Bulletin No. 962000. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2006c. Geoprobe® 10-in. x 2.5-in. OD and 1.5-in. x 2.5-in. OD Prepacked Screen Monitoring Wells, Standard Operating Procedure. Technical Bulletin No. 992500. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2009a. Geoprobe® 2.0-in. x 3.4-in. OD Prepacked Screen Monitoring Wells, Standard Operating Procedure. Technical Bulletin No. MK3172. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2009b. Geoprobe® Slug Test Analysis (STA) Software V2.0, User's Guide.. Technical Bulletin No. MK3087. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Geoprobe® 2010. Geoprobe° Screen Point 22 Groundwater Sampler, Standard Operating Procedure. Technical Bulletin No. MK3173. Kejr Inc. 1835 Wall St., Salina, KS. www.geoprobe.com Hvorslev, M.J., 1951. Time Lag and Soil Permeability in Ground Water Observations. U.S. Army Corps of Engineers Waterway Experiment Station, Bulletin 36. McCall, Wesley, James J. Butler, John M. Healey, Alyssa A. Lanier, Stephen M. Sellwood and Elizabeth J. Garnett. 2002. A Dual - Tube Direct -Push Method for Vertical Profiling of Hydraulic Conductivity in Unconsolidated Formations. Environ. & Eng. Geoscience, Vol. VIII, No. 2, May. Pages 75-84. McCall, Wesley, David M. Nielsen, Stephen P. Farrington and Thomas M. Christy, 2006. Ch. 6: Use of Direct -Push Technologies in Environmental Site Characterization and Ground -Water Monitoring in Handbook of Environmental Site Characterization and Ground -Water Monitoring, 2nd Ed. CRC Press, Boca Raton, FL. www.crcpress.com McCall, Wesley, Thomas M. Christy, Thomas Christopherson and Howard Issacs, 2009. Application of Direct Push Methods to Investigate Uranium Distribution in an Alluvial Aquifer. Ground Water Mon. & Rem. Vol. 29, No. 4, pages 65-76. Fall. Installation/Operation Instructions 15 Pneumatic Slug Test Kit Geoprobe® Slug Test Field Data Form Site Name: Well No: Screen Interval: _ Operator: Date: File Name(s): FileTime (sec) Ho (in/cm) Rise Fall Notes MIP/HPT/EC/CPT log filename: Sample Nos. Aquifer Type: Unconfined Confined Screen Penetration: Full Partial Geologic Formation/Soils: Leaky Confined Perched Aquifer Thickness Installation/Operation Instructions 16 Pneumatic Slug Test Kit Geoprobe® and Geoprobe Systems®, Macro -Core®, and Direct Image® are Registered Trademarks of Kejr, Inc., Salina, Kansas. Equipment and tool specifications, including weights, dimensions, materials, and operating specifications included in this document are subject to change without notice. Where specifications are critical to your application, please contact Geoprobe° Systems. © 2014 Kejr, Inc. ALL RIGHTS RESERVED. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without written permission from Kejr, Inc. Installation/Operation Instructions 17 Pneumatic Slug Test Kit Geoprobe Systems® A DIVISION OF KEJR, INC. 1835 Wall St. • Salina, KS 67401 1-800-436-7762 • FAX 785-825-2097 www.geoprobe.com