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Home My WebLink AboutTech Memo - Proposed Additional Shallow Soil SamplingL� synTerra TECHNICAL MEMORANDUM Date: February 20, 2019 File: 1026.17 To: Courtney Murphy (Duke Energy) Cc: Kathy Webb (SynTerra); Lee Drago (SynTerra) From: Chris Suttell C:75 Subject: Proposed Additional Shallow Soil Sampling - Allen Steam Station Duke Energy Carolinas, LLC (Duke Energy) owns and operates the Allen Steam Station (Allen, Plant, or Site) in Belmont, Gaston County, North Carolina. Further soil delineation at the Site has been requested by North Carolina Division of Environmental Quality (NCDEQ) Mooresville Regional Office (MRO). Additional soil assessment activities proposed for the Site are described herein. Soil Assessment Objectives The objective of the soil assessment is to characterize inorganic constituent concentrations in shallow, unsaturated soils downgradient of the Active and Retired Ash Basins. Soil Assessment As requested by NCDEQ MRO, shallow soil sample locations are proposed on the attached map where horizontal delineation is deemed appropriate. In an effort to delineate the unsaturated soils downgradient of the ash basins, 10 soil sample locations are proposed for this assessment (Figure 1). Two unsaturated sample intervals would be collected at each location: one shallow soil sample [0.5-1 feet (ft) below ground surface (bgs)] and a secondary soil sample (2-3 ft bgs). Should the water table be shallower than anticipated at a sample location, the sample interval would be adjusted accordingly. To bolster the current data set, soils collected during the recent Coal Pile Assessment would be also considered in this assessment. A total of 11 unsaturated soil samples were collected during the Allen Coal Pile Assessment, ranging in depths from 2-9 ft bgs. Coal Pile Assessment soil sampling locations are also shown on Figure 1. \ \ synterracorp.com \ Data \ Proj \ Duke Energy Carolinas \ 17.ALLEN \ 05.EHS CAMA Compliance Support \ Assessment\ Additional Soil Sampling 2019\Tech Memo - Proposed Additional Shallow Soil Sampling Final.docx Allen Steam Station Proposed Additional Soil Sampling February 18, 2019 Allen Steam Station Page 2 of 3 Constituents that had historical detection limits above the North Carolina Preliminary Soil Remediation Goals Protection of Groundwater (POG) at the Site included antimony, arsenic, cobalt, selenium, and thallium. Samples would be analyzed for these and other inorganic constituents using analytical methods with detection limits less than the POG, as summarized on Table 1. Soil sampling would be performed in general accordance with the procedures specified in Section 4 in the U.S. EPA SESD Operating Procedure for Soil Sampling (Appendix 1). ATTACHMENTS: Figure 1: Proposed Shallow Soil Sample Locations Table 1: Soil Analytical Methods Appendix 1: U.S. Environmental Protection Agency Science and Ecosystem Support Division SESD Operating Procedure for Soil Sampling \ \ synterracorp.com \ Data \ Proj \ Duke Energy Carolinas \ 17.ALLEN \ 05.EHS CAMA Compliance Support\ Assessment\ Additional Soil Sampling 2019\Tech Memo - Proposed Additional Shallow Soil Sampling Final.docx Allen Steam Station Proposed Additional Soil Sampling February 18, 2019 Allen Steam Station ATTACHMENTS \ \ synterracorp.com \ Data \ Proj \ Duke Energy Carolinas \ 17.ALLEN \ 05.EHS CAMA Compliance Support \ Assessment\ Additional Soil Sampling 2019\Tech Memo - Proposed Additional Shallow Soil Sampling Final.docx ILE LOCATIONS WERRE DERIVED FROM VARIOUS SOURCE: ARE A MIX OF SURVEYED AND APPROXIMATE LOCATIONS. ;EFORE. SAMPLE LOCATIONS ARE TO BE DEEMEE PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO ON :R 11, 2017. AERIAL WAS COLLECTED ON OCTOBER 8, 2016. NG HAS BEEN SET WITH A PROJECTION OF NORTH PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). '% -:-t ,* I BG-3S Y � `, � - , — I • - t' r CP-3S/D CCR-26S/D/BR 1 �� 1♦ p`` ON RO p0 LpjO� O� • � ®� GWA-8S/SA � P N CP-2SID CP-4S/D • GWA-17S/D R CCR-3S/DA O CP-1S/D r �� AB-1 l CCR-2S/D a CCR-3D GWA-6S/DA O CP-5S/D 1 • AB-1R CCR-1S/DA CCR-1D��_ • •'• CCR-4SA/DA �. GWA ,18S/D - , GWA-6D/BR h � � - /■ .:. CCR-4S/D • • l BG-2BR " BG-BRA2 1�i�, AB-38S/SS/BR CCR-SS/D " CCR-7S/D CP-6BR ®= C • q• . •� CR-8S/D � �• / 1 � CCR-6S/D _ _ � CP-6S/D/BR • bit GW _A-16S/DI " AB-33SS CCR-9S/D 'LL .. CCR-BG-1S�1D �• CCR-B~ OO -32D'® �a GWA-5BRA GWA-19S/6y, •• � ® • CCR-11SIDA �� AB-37S CCR-11 D � • _ AB-35PWA/SS AB-31S �° ; • "' = :. �# GWA-15S O ®AB-350WAU/OWAL/OWAL30 _ - _ - _ - ` ° ' GWA-4BR �J AB-14D/BR AB-2/D ♦� AB-29S/SL/SS ♦ AB-30S AB-9S/D GWA-14S/DA �4 •` ck AB-27S/BR GWA-14D AB-28S �® ,r 1 A`B-8 0 :L ,r GWA-22S/D PN-1D' PN-2D CCR-14S/D GWA-21S/DA/BR , GWA-3 ° GWA-21D AB-1 3S/D AB-24S/SL/BR , GWA-i aN,StRONG ROpD. AB-25S/SS .:®.. N AB-4S/D/BR ,GWA-23S/D c AB-23S CCR-16S/D/BR C4. CIF WELL '! g GWA-9D/BR '�"6 ;)rCCR-17S/D ~ y - + GWA-24SA/D/BR ! j AB-22S/BR/BRL AB-10S/D GWA-24S LEGEND •PROPOSED SHALLOW SOIL SAMPLE LOCATION OCOAL PILE ASSESSMENT SOIL SAMPLE LOCATION SOILAND GROUNDWATER SAMPLING LOCATION SOIL SAMPLING LOCATION O GROUNDWATER SAMPLING LOCATION ABANDONED MONITORING WELL O CCR RULE GROUNDWATER MONITORING WELL • ABANDONED CCR RULE GROUNDWATER MONITORING WELL ASH BASIN WASTE BOUNDARY INACTIVE ASH BASIN WASTE BOUNDARY LANDFILL BOUNDARY DORS FILLS BOUNDARIES ASH BASIN COMPLIANCE BOUNDARY LANDFILL COMPLIANCE BOUNDARY DUKE ENERGY CAROLINAS ALLEN PLANT SITE BOUNDARY AB-21S/SL/SS/BRL' `%� AB-6A AB-21PWA/PWS/0WAU/0WAL CCR-18�S/DJ+4-6�R-, 7i►'s �►�+l� CCR-21S/D pH WELL �♦ ram♦.'. a : "?'� .i''''' .CCR-22D • CCR-22S/DA GWA-2S �O GWA-26S/D GWA-1 BR � CCR-23S/D h'V BG-1S/DA/BR �♦� AB-11 D � - - — - 14' synTerra a r• 370 0 370 740 GRAPHIC SCALE IN FEET 148 RIVER STREET, SUITE 220 GREENVILLE, SOUTH CAROLINA 29601 PHONE 864-421-9999 DUKE synterra ENERGY PRRI O ECT MANAGER` C. SUTTELL DATE: 02/20/2019 (D INAS CHECKED BY: L. DRAGO a FIGURE 1 PROPOSED SHALLOW AND COAL PILE ASSESSMENT SOIL SAMPLE LOCATIONS ALLEN STEAM STATION DUKE ENERGY CAROLINAS, LLC TABLE 1 SOIL ANALYTICAL METHODS ALLEN STEAM STATION DUKE ENERGY CAROLINAS, LLC, BELMONT, NC INORGANIC COMPOUNDS UNITS METHOD Aluminum mg/kg EPA 6010D Antimony mg/kg EPA 6020B Arsenic mg/kg EPA 6020B Barium mg/kg EPA 6010D Beryllium mg/kg EPA 6010D Boron mg/kg EPA 6010D Cadmium mg/kg EPA 6020B Calcium mg/kg EPA 6010D Chloride mg/kg EPA 9056A Chromium mg/kg EPA 6010C Cobalt mg/kg EPA 6020A Copper mg/kg EPA 6010C Iron mg/kg EPA 6010C Lead mg/kg EPA 6020B Magnesium mg/kg EPA 6010D Manganese mg/kg EPA 6010C Mercury mg/kg EPA 7471 B Molybdenum mg/kg EPA 6010D Nickel mg/kg EPA 6010C Nitrate as Nitrogen mg/kg EPA 9056A pH SU EPA 9045D Potassium mg/kg EPA 6010D Selenium mg/kg EPA 6020B Sodium mg/kg EPA 6010D Strontium mg/kg EPA 6010D Sulfate mg/kg EPA 9056A Thallium (total, low level) mg/kg EPA 6020B Total Organic Carbon mg/kg EPA 9060 Vanadium mg/kg EPA 6020B Zinc mq/kq EPA 6010C Prepared by: RBI Checked by: WJW Notes: 1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above. 2. Select soil samples will also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020. 3. Analytical methods and reporting limits as presented were applicable at time of CSA field implementation in 2015. Analytical methods and reporting limits are updated periodically and applied as appropriate. meq/100g - millequivalents per 100 grams mg/kg - Milligrams per kilogram my - Millivolts S.U. - Standard Unit P:\Duke Energy Carolinas\17.ALLEN\05.EHS CAMA Compliance Support\Assessment\Additional Soil Sampling 2019\ Table 1 - Soil Analytical Methods Page 1 of 1 COPY Region 4 U.S. Environmental Protection Agency Science and Ecosystem Support Division Athens, Georgia Title: Soil Effective Date: December 20, 2011 Number: SESDPROC-300-R2 Authors Name: Fred Sloan Title: Enviro2ntal gineer, Regional Expert Signature: - Date: 17,1 IV e z0 f l Approvals Name: Archie Lee Title: Chief, Enforcement and Investigations Branch Date: Name: hobby Lewis ' Title: Field Quality Manager, Science and Ecosystem Support Division Signature: / ;� Date: SESD Operating Procedure Page 1 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY Revision History This table shows changes to this controlled document over time. The most recent version is presented in the top row of the table. Previous versions of the document are maintained by the SESD Document Control Coordinator. History Effective Date SESDPROC-300-R2, Soil Sampling, replaces SESDPROC- December 20, 2011 300-R1. General: Corrected any typographical, grammatical and/or editorial errors. Title Page: Updated the Enforcement and Investigations Branch Chief to Archie Lee, and the Field Quality Manager to Bobby Lewis. Revision History: On the third sentence, replaced Field Quality Manager with Document Control Coordinator. Section 1.2: Added the following statement: Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. Section 1.3: Revised the last sentence to reflect that the official copy of this procedure resides on the SESD local area network (LAN), and that the Document Control Coordinator is responsible for ensuring the most recent version of the procedure is placed on the LAN. Section 1.4: Unused references removed. Reference to Method 5035 added. Alphabetized. Section 1.5.2: Added bullets #8 and #9. (Bullet #8 — Discussion of sampling in landscaped areas. Bullet #9 — Discussion of sampling in non -landscaped areas.) Section 2: The discussion of Method 5035 has been moved to its own Section (Section 3) for clarity. Subsequent Sections were re -numbered. Section 4.1: Added paragraphs #2 and #3. (The information on these paragraphs originally appeared as bullets #2 and #3 in Section 4.2.1.) In addition, determining the initial sampling depth is now defined in paragraph #2. Section 4.2.1: As mentioned above, deleted bullets #2 and #3 from this Section and moved this information to paragraphs #2 and #3 in Section 4.1. Section 5.1: On paragraph #1, rewrote sentences #2 and #3 for clarity. Added the last sentence. Added paragraph #2. SESD Operating Procedure Page 2 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)—AF.R2 Effective Date: December 20, 2011 COPY Section 5.3: Rewrote the last sentence in the paragraph to clarify that, "although the Macro -Core® sampler can be used as an open -barrel sampler, in SESD usage, the piston point is always used to prevent the collection of slough from the borehole sides." Section 5.5: Rewrote bullet #1 to clarify acceptable materials for liners. Rewrote bullet #3 (Core Catchers) to clarify that, given the limited sample contact that core -catchers have with the sample material, most standard core -catchers available for a tool system will be acceptable. Added bullets #4 (Decontamination) and #5 (Decommissioning). Section 6.1: Added paragraph 42 to this section. (Determining the initial sampling depth is now defined.) Section 7.1: Added paragraph #2 to this section. (Determining the initial sampling depth is now defined.) Section 8.1: Added paragraph #2 to this section. (Determining the initial sampling depth is now defined.) SESDPROC-300-R1, Soil Sampling, replaces SESDPROC- November 1, 2007 300-R0. General Corrected any typographical, grammatical and/or editorial errors. Title Page Changed title for Antonio Quinones from Environmental Investigations Branch to Enforcement and Investigations Branch. Section 1.3 Updated information to reflect that the procedure is located on the H: drive of the LAN. Clarified Field Quality Manager (FQM) responsibilities. Section 1.4 Updated referenced operating procedures due to changes in title names. Alphabetized and revised the referencing style for consistency. Section 1.5.1 Corrected the title of the Safety, Health, and Environmental Management Program Procedures and Policy Manual. Section 1.5.2, 4th bullet Added references to the CFR and IATA's Dangerous Goods Regulations. Section 2.7 Updated referenced operating procedures due to changes in title names. FSESDPROC-300-RO, Soil Sampling, Original Issue February 05, 2007 SESD Operating Procedure Page 3 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY TABLE OF CONTENTS 1 General Information.................................................................................................6 1.1 Purpose................................................................................................................6 1.2 Scope/Application.............................................................................................. 6 1.3 Documentation/Verification..............................................................................6 1.4 References...........................................................................................................6 1.5 General Precautions........................................................................................... 7 1.5.1 Safety............................................................................................................ 7 1.5.2 Procedural Precautions............................................................................... 7 2 Special Sampling Considerations............................................................................ 9 2.1 Special Precautions for Trace Contaminant Soil Sampling ........................... 9 2.2 Sample Homogenization.................................................................................... 9 2.3 Dressing Soil Surfaces......................................................................................10 2.4 Quality Control................................................................................................ 10 2.5 Records..............................................................................................................10 3 Method 5035............................................................................................................ 11 3.1 Soil Samples for Volatile Organic Compounds (VOC) Analysis.................11 3.2 Soil Sampling (Method 5035)..........................................................................11 3.2.1 Equipment.................................................................................................. 11 3.2.2 Sampling Methodology - Low Concentrations (<200 pg/kg) ...................11 3.2.3 Sampling Methodology - High Concentrations(>200,ug/kg)..................12 3.2.4 Special Techniques and Considerations for Method 5035.......................13 Table 1: Method 5035 Summary..........................................................................15 4 Manual Soil Sampling Methods............................................................................. 16 4.1 General..............................................................................................................16 4.2 Spoons...............................................................................................................16 4.2.1 Special Considerations When Using Spoons ............................................ 16 4.3 Hand Augers.....................................................................................................16 4.3.1 Surface Soil Sampling...............................................................................17 4.3.2 Subsurface Soil Sampling.......................................................................... 17 4.3.3 Special Considerations for Soil Sampling with the Hand Auger.............17 5 Direct Push Soil Sampling Methods..................................................................... 18 5.1 General..............................................................................................................18 5.2 Large Bore® Soil Sampler.............................................................................. 18 5.3 Macro -Core® Soil Sampler.............................................................................18 5.4 Dual Tube Soil Sampling System................................................................... 19 5.5 Special Considerations When Using Direct Push Sampling Methods ........19 SESD Operating Procedure Page 4 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 6 Split Spoon/Drill Rig Methods............................................................................... 21 6.1 General..............................................................................................................21 6.2 Standard Split Spoon....................................................................................... 21 6.3 Continuous Split Spoon................................................................................... 21 6.4 Special Considerations When Using Split Spoon Sampling Methods......... 22 7 Shelby Tube/Thin-Walled Sampling Methods ..................................................... 23 7.1 General..............................................................................................................23 7.2 Shelby Tube Sampling Method...................................................................... 23 7.3 Special Considerations When Using Split Spoon Sampling Methods......... 23 8 Backhoe Sampling Method.................................................................................... 24 8.1 General..............................................................................................................24 8.2 Scoop -and -Bracket Method............................................................................ 24 8.3 Direct -from -Bucket Method........................................................................... 24 8.4 Special Considerations When Sampling with a Backhoe ............................. 24 TABLES Table 1: Method 5035 Summary................................................................15 SESD Operating Procedure Page 5 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 1 General Information 1.1 Purpose This document describes general and specific procedures, methods and considerations to be used and observed when collecting soil samples for field screening or laboratory analysis. 1.2 Scope/Application The procedures contained in this document are to be used by field personnel when collecting and handling soil samples in the field. On the occasion that SESD field personnel determine that any of the procedures described in this section are inappropriate, inadequate or impractical and that another procedure must be used to obtain a soil sample, the variant procedure will be documented in the field logbook and subsequent investigation report, along with a description of the circumstances requiring its use. Mention of trade names or commercial products in this operating procedure does not constitute endorsement or recommendation for use. 1.3 Documentation/Verification This procedure was prepared by persons deemed technically competent by SESD management, based on their knowledge, skills and abilities and have been tested in practice and reviewed in print by a subject matter expert. The official copy of this procedure resides on the SESD local area network (LAN). The Document Control Coordinator (DCC) is responsible for ensuring the most recent version of the procedure is placed on the LAN, and for maintaining records of review conducted prior to its issuance. 1.4 References International Air Transport Authority (IATA). Dangerous Goods Regulations, Most Recent Version SESD Operating Procedure for Field Equipment Cleaning and Decontamination, SESDPROC-205, Most Recent Version SESD Operating Procedure for Field Equipment Cleaning and Decontamination at the FEC, SESDPROC-206, Most Recent Version SESD Operating Procedure for Field Sampling Quality Control, SESDPROC-011, Most Recent Version SESD Operating Procedure for Field X-Ray Fluorescence (XRF) Measurement, SESDPROC-107, Most Recent Version SESD Operating Procedure Page 6 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY SESD Operating Procedure for Logbooks, SESDPROC-010, Most Recent Version SESD Operating Procedure for Sample and Evidence Management, SESDPROC-005, Most Recent Version Title 49 Code of Federal Regulations, Pts. 171 to 179, Most Recent Version US EPA Test Methods for Evaluating Solid Waste, Physical/Chemical Methods SW-846, Most Recent Version (Method 5035) US EPA. Safety, Health and Environmental Management Program (SHEMP) Procedures and Policy Manual. Region 4 SESD, Athens, GA, Most Recent Version 1.5 General Precautions 1.5.1 Safety Proper safety precautions must be observed when collecting soil samples. Refer to the SESD Safety, Health and Environmental Management Program (SHEMP) Procedures and Policy Manual and any pertinent site -specific Health and Safety Plans (HASP) for guidelines on safety precautions. These guidelines, however, should only be used to complement the judgment of an experienced professional. Address chemicals that pose specific toxicity or safety concerns and follow any other relevant requirements, as appropriate. 1.5.2 Procedural Precautions The following precautions should be considered when collecting soil samples. • Special care must be taken not to contaminate samples. This includes storing samples in a secure location to preclude conditions which could alter the properties of the sample. Samples shall be custody sealed during long-term storage or shipment. • Collected samples are in the custody of the sampler or sample custodian until the samples are relinquished to another party. • If samples are transported by the sampler, they will remain under his/her custody or be secured until they are relinquished. • Shipped samples shall conform to all U.S. Department of Transportation (DOT) rules of shipment found in Title 49 of the Code of Federal Regulations (49 CFR parts 171 to 179), and/or International Air Transportation Association (IATA) hazardous materials shipping requirements found in the current edition of IATA's Dangerous Goods Regulations. • Documentation of field sampling is done in a bound logbook. SESD Operating Procedure Page 7 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY • Chain -of -custody documents shall be filled out and remain with the samples until custody is relinquished. • All shipping documents, such as air bills, bills of lading, etc., shall be retained by the project leader in the project files. • Sampling in landscaped areas: When sampling in landscaped areas, cuttings should be placed on plastic sheeting and returned to the borehole upon completion of the sample collection. Any `turf plug' generated during the sampling process should be returned to the borehole. • Sampling in non -landscaped areas: Return any unused sample material back to the auger, drill or push hole from which the sample was collected. SESD Operating Procedure Page 8 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 2 Special Sampling Considerations 2.1 Special Precautions for Trace Contaminant Soil Sampling • A clean pair of new, non -powdered, disposable gloves will be worn each time a different sample is collected and the gloves should be donned immediately prior to sampling. The gloves should not come in contact with the media being sampled and should be changed any time during sample collection when their cleanliness is compromised. • Sample containers for samples suspected of containing high concentrations of contaminants shall be collected, handled and stored separately. • All background samples shall be segregated from obvious high -concentration or waste samples. Sample collection activities shall proceed progressively from the least suspected contaminated area to the most suspected contaminated area. Samples of waste or highly -contaminated media must not be placed in the same ice chest as environmental (i.e., containing low contaminant levels) or background samples. • If possible, one member of the field sampling team should take all the notes and photographs, fill out tags, etc., while the other member(s) collect the samples. • Samplers must use new, verified/certified-clean disposable or non -disposable equipment cleaned according to procedures contained in the SESD Operating Procedure for Field Equipment Cleaning and Decontamination (SESDPROC- 205), for collection of samples for trace metals or organic compound analyses. 2.2 Sample Homogenization If sub -sampling of the primary sample is to be performed in the laboratory, transfer the entire primary sample directly into an appropriate, labeled sample container(s). Proceed to step 4. 2. If sub -sampling the primary sample in the field or compositing multiple primary samples in the field, place the sample into a glass or stainless steel homogenization container and mix thoroughly. Each aliquot of a composite sample should be of the same approximate volume. 3. All soil samples must be thoroughly mixed to ensure that the sample is as representative as possible of the sample media. Samples for VOC analysis are not homogenized. The most common method of mixing is referred to as quartering. The quartering procedure should be performed as follows: SESD Operating Procedure Page 9 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY • The material in the sample pan should be divided into quarters and each quarter should be mixed individually. • Two quarters should then be mixed to form halves. • The two halves should be mixed to form a homogenous matrix. This procedure should be repeated several times until the sample is adequately mixed. If round bowls are used for sample mixing, adequate mixing is achieved by stirring the material in a circular fashion, reversing direction, and occasionally turning the material over. 4. Place the sample into an appropriate, labeled container(s) by using the alternate shoveling method and secure the cap(s) tightly. The alternate shoveling method involves placing a spoonful of soil in each container in sequence and repeating until the containers are full or the sample volume has been exhausted. Threads on the container and lid should be cleaned to ensure a tight seal when closed. 2.3 Dressing Soil Surfaces Any time a vertical or near vertical surface is sampled, such as achieved when shovels or similar devices are used for subsurface sampling, the surface should be dressed (scraped) to remove smeared soil. This is necessary to minimize the effects of contaminant migration interferences due to smearing of material from other levels. 2.4 Quality Control If possible, a control sample should be collected from an area not affected by the possible contaminants of concern and submitted with the other samples. This control sample should be collected as close to the sampled area as possible and from the same soil type. Equipment blanks should be collected if equipment is field cleaned and re -used on -site or if necessary to document that low-level contaminants were not introduced by sampling tools. SESD Operating Procedure for Field Sampling Quality Control (SESDPROC-011) contains other procedures that may be applicable to soil sampling investigations. 2.5 Records Field notes, recorded in a bound field logbook, will be generated, as well as chain -of - custody documentation, as described in the SESD Operating Procedure for Logbooks (SESDPROC-010) and the SESD Operating Procedure for Sample and Evidence Management (SESDPROC-005). SESD Operating Procedure Page 10 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 3 Method 5035 The procedures outlined here are summarized from Test Methods for Evaluating Solid Waste, Physical/Chemical Methods SW-846, Method 5035. 3.1 Soil Samples for Volatile Organic Compounds (VOC) Analysis If samples are to be analyzed for volatile organic compounds, they should be collected in a manner that minimizes disturbance of the sample. For example, when sampling with an auger bucket, the sample for VOC analysis should be collected directly from the auger bucket (preferred) or from minimally disturbed material immediately after an auger bucket is emptied into the pan. The sample shall be containerized by filling an En Core® Sampler or other Method 5035 compatible container. Samples for VOC analysis are not homogenized. Preservatives may be required for some samples with certain variations of Method 5035. Consult the method or the principal analytical chemist to determine if preservatives are necessary. 3.2 Soil Sampling (Method 5035) The following sampling protocol is recommended for site investigators assessing the extent of volatile organic compounds (VOCs) in soils at a project site. Because of the large number of options available, careful coordination between field and laboratory personnel is needed. The specific sampling containers and sampling tools required will depend upon the detection levels and intended data use. Once this information has been established, selection of the appropriate sampling procedure and preservation method best applicable to the investigation can be made. 3.2.1 Equipment Soil for VOC analyses may be retrieved using any of the SESD soil sampling methods described in Sections 4 through 8 of this procedure. Once the soil has been obtained, the En Core® Sampler, syringes, stainless steel spatula, standard 2-oz. soil VOC container, or pre -prepared 40 mL vials may be used/required for sub -sampling. The specific sample containers and the sampling tools required will depend upon the data quality objectives established for the site or sampling investigation. The various sub -sampling methods are described below. 3.2.2 Sampling Methodology -Low Concentrations (<200,ug/kg) When the total VOC concentration in the soil is expected to be less than 200 µg/kg, the samples may be collected directly with the En Core® Sampler or syringe. If using the syringes, the sample must be placed in the sample container (40 mL pre -prepared vial) immediately to reduce volatilization losses. The 40 mL SESD Operating Procedure Page 11 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY vials should contain 10 mL of organic -free water for an un-preserved sample or approximately 10 mL of organic -free water and a preservative. It is recommended that the 40 mL vials be prepared and weighed by the laboratory (commercial sources are available which supply preserved and tared vials). When sampling directly with the En Core® Sampler, the vial must be immediately capped and locked. A soil sample for VOC analysis may also be collected with conventional sampling equipment. A sample collected in this fashion must either be placed in the final sample container (En Core(b Sampler or 40 mL pre -prepared vial) immediately or the sample may be immediately placed into an intermediate sample container with no head space. If an intermediate container (usually 2-oz. soil jar) is used, the sample must be transferred to the final sample container (En Core® Sampler or 40 mL pre -prepared vial) as soon as possible, not to exceed 30 minutes. NOTE:After collection of the sample into either the En Core® Sampler or other container, the sample must immediately be stored in an ice chest and cooled. Soil samples may be prepared for shipping and analysis as follows: En Core® Sampler - the sample shall be capped, locked, and secured in the original foil bag. All foil bags containing En Core® samplers are then placed in a plastic bag and sealed with custody tape, if required. Syringe - Add about 3.7 cc (approximately 5 grams) of sample material to 40-mL pre -prepared containers. Secure the containers in a plastic bag. Do not use a custody seal on the container; place the custody seal on the plastic bag. Note: When using the syringes, it is important that no air is allowed to become trapped behind the sample prior to extrusion, as this will adversely affect the sample. Stainless Steel Laboratory Spatulas - Add between 4.5 and 5.5 grams (approximate) of sample material to 40 mL containers. Secure the containers in a plastic bag. Do not use a custody seal on the container; place the custody seal on the plastic bag. 3.2.3 Sampling Methodology - High Concentrations (>200 pg/kg) Based upon the data quality objectives and the detection level requirements, this high level method may also be used. Specifically, the sample may be packed into a single 2-oz. glass container with a screw cap and septum seal. The sample container must be filled quickly and completely to eliminate head space. Soils\sediments containing high total VOC concentrations may also be collected as described in Section 3.2.2, Sampling Methodology - Low Concentrations, and preserved using 10 mL methanol. SESD Operating Procedure Page 12 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 3.Z4 Special Techniques and Considerations for Method 5035 Effervescence If low concentration samples effervesce from contact with the acid preservative, then either a test for effervescence must be performed prior to sampling, or the investigators must be prepared to collect each sample both preserved or un-preserved, as needed, or all samples must be collected unpreserved. To check for effervescence, collect a test sample and add to a pre -preserved vial. If preservation (acidification) of the sample results in effervescence (rapid formation of bubbles) then preservation by acidification is not acceptable, and the sample must be collected un-preserved. If effervescence occurs and only pre -preserved sample vials are available, the preservative solution may be placed into an appropriate hazardous waste container and the vials triple rinsed with organic free water. An appropriate amount of organic free water, equal to the amount of preservative solution, should be placed into the vial. The sample may then be collected as an un-preserved sample. Note that the amount of organic free water placed into the vials will have to be accurately measured. Sample Size While this method is an improvement over earlier ones, field investigators must be aware of an inherent limitation. Because of the extremely small sample size and the lack of sample mixing, sample representativeness for VOCs may be reduced compared to samples with larger volumes collected for other constituents. The sampling design and objectives of the investigation should take this into consideration. Holding Times Sample holding times are specified in the Analytical Support Branch Laboratory Operations and Quality Assurance Manual (ASBLOQAM), Most Recent Version. Field investigators should note that the holding time for an un-preserved VOC soil/sediment sample on ice is 48 hours. Arrangements should be made to ship the soil/sediment VOC samples to the laboratory by overnight delivery the day they are collected so the laboratory may preserve and/or analyze the sample within 48 hours of collection. Percent Moisture and Preservative Compatibility (MOICA) Samplers must ensure that the laboratory has sufficient material to determine percent moisture in the VOC soil/sediment sample to correct the analytical results to dry weight. If other analyses requiring percent moisture determination are SESD Operating Procedure Page 13 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY being performed upon the sample, these results may be used. If not, a separate sample (minimum of 2 oz.) for percent moisture determination will be required. The sample collected for percent moisture may also be used by the laboratory to check for preservative compatibility. Safety Methanol is a toxic and flammable liquid. Therefore, methanol must be handled with all required safety precautions related to toxic and flammable liquids. Inhalation of methanol vapors must be avoided. Vials should be opened and closed quickly during the sample preservation procedure. Methanol must be handled in a ventilated area. Use protective gloves when handling the methanol vials. Store methanol away from sources of ignition such as extreme heat or open flames. The vials of methanol should be stored in a cooler with ice at all times. Shipping Methanol and sodium bisulfate are considered dangerous goods, therefore shipment of samples preserved with these materials by common carrier is regulated by the U.S. Department of Transportation and the International Air Transport Association (IATA). The rules of shipment found in Title 49 of the Code of Federal Regulations (49 CFR parts 171 to 179) and the current edition of the IATA Dangerous Goods Regulations must be followed when shipping methanol and sodium bisulfate. Consult the above documents or the carrier for additional information. Shipment of the quantities of methanol and sodium bisulfate used for sample preservation falls under the exemption for small quantities. The summary table on the following page lists the options available for compliance with SW846 Method 5035. The advantages and disadvantages are noted for each option. SESD's goal is to minimize the use of hazardous material (methanol and sodium bisulfate) and minimize the generation of hazardous waste during sample collection. SESD Operating Procedure Page 14 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY Table 1: Method 5035 Summary OPTION PROCEDURE ADVANTAGES DISADVANTAGES 1 Collect two 40 mL vials with Screening conducted by Presently a 48-hour z 5 grams of sample, and one lab. holding time for 2 oz. glass Pr w/septum lid for unpreserved samples. screening, /o moisture and Sample containers must preservative compatibility. be tared. 2 Collect three En Core® Lab conducts all Presently a 48- hour samplers, and one 2 oz. glass preservation/preparation holding time for jar w/septum lid for screening, procedures. preparation of samples. moisture and preservative compatibility. 3 Collect two 40 mL vials with High level VOC Hazardous materials 5 grams of sample and samples may be used in the field. preserve w/methanol or composited. Sample containers must sodium bisulfate, and one Longer holding time. be tared. 2-oz. glass jar w/septum lid for screening, /o moisture and preservative compatibility. 4 Collect one 2-oz. glass jar Lab conducts all May have significant w/septum lid for analysis, preservation/preparation VOC loss. % moisture and preservative procedures. com atibility (high level VOC only. SESD Operating Procedure Page 15 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 4 Manual Soil Sampling Methods 4.1 General These methods are used primarily to collect surface and shallow subsurface soil samples. Surface soils are generally classified as soils between the ground surface and 6 to 12 inches below ground surface. The most common interval is 0 to 6 inches; however, the data quality objectives of the investigation may dictate another interval, such as 0 to 3 inches for risk assessment purposes. The shallow subsurface interval may be considered to extend from approximately 12 inches below ground surface to a site -specific depth at which sample collection using manual collection methods becomes impractical. If a thick, matted root zone, gravel, concrete, etc. is present at or near the surface, it should be removed before the sample is collected. The depth measurement for the sample begins at the top of the soil horizon, immediately following any removed materials. When compositing, make sure that each composite location (aliquot) consist of equal volumes, i.e., same number of equal spoonfuls. 4.2 Spoons Stainless steel spoons may be used for surface soil sampling to depths of approximately 6 inches below ground surface where conditions are generally soft and non -indurated, and there is no problematic vegetative layer to penetrate. 4.2.1 Special Considerations When Using Spoons • When using stainless steel spoons, consideration must be given to the procedure used to collect the volatile organic compound sample. If the soil being sampled is cohesive and holds its in situ texture in the spoon, the En Core® Sampler or syringe used to collect the sub -sample for Method 5035 should be plugged directly from the spoon. If, however, the soil is not cohesive and crumbles when removed from the ground surface for sampling, consideration should be given to plugging the sample for Method 5035 directly from the ground surface at a depth appropriate for the investigation Data Quality Objectives. 4.3 Hand Augers Hand augers may be used to advance boreholes and collect soil samples in the surface and shallow subsurface intervals. Typically, 4-inch stainless steel auger buckets with cutting heads are used. The bucket is advanced by simultaneously pushing and turning using an attached handle with extensions (if needed). SESD Operating Procedure Page 16 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 4.3.1 Surface Soil Sampling When conducting surface soil sampling with hand augers, the auger buckets may be used with a handle alone or with a handle and extensions. The bucket is advanced to the appropriate depth and the contents are transferred to the homogenization container for processing. Observe precautions for volatile organic compound sample collection found in Section 3, Method 5035. 4.3.2 Subsurface Soil Sampling Hand augers are the most common equipment used to collect shallow subsurface soil samples. Auger holes are advanced one bucket at a time until the sample depth is achieved. When the sample depth is reached, the bucket used to advance the hole is removed and a clean bucket is attached. The clean auger bucket is then placed in the hole and filled with soil to make up the sample and removed. The practical depth of investigation using a hand auger depends upon the soil properties and depth of investigation. In sand, augering is usually easily performed, but the depth of collection is limited to the depth at which the sand begins to flow or collapse. Hand augers may also be of limited use in tight clays or cemented sands. In these soil types, the greater the depth attempted, the more difficult it is to recover a sample due to increased friction and torqueing of the hand auger extensions. At some point these problems become so severe that power equipment must be used. 4.3.3 Special Considerations for Soil Sampling with the Hand Auger • Because of the tendency for the auger bucket to scrape material from the sides of the auger hole while being extracted, the top several inches of soil in the auger bucket should be discarded prior to placing the bucket contents in the homogenization container for processing. • Observe precautions for volatile organic compound sample collection found in Section 3, Method 5035. Collect the VOC sample directly from the auger bucket, if possible. • Power augers, such as the Little Beaver® and drill rigs may be used to advance boreholes to depths for subsurface soil sampling with the hand auger. They may not be used for sample collection. When power augers are used to advance a borehole to depth for sampling, care must be taken that exhaust fumes, gasoline and/or oil do not contaminate the borehole or area in the immediate vicinity of sampling. • When moving to a new sampling location, the entire hand auger assembly must be replaced with a properly decontaminated hand auger assembly. SESD Operating Procedure Page 17 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 5 Direct Push Soil Sampling Methods 5.1 General These methods are used primarily to collect shallow and deep subsurface soil samples. Three samplers are available for use within the Division's direct push tooling inventory. All of the sampling tools involve the collection and retrieval of the soil sample within a thin -walled liner. The following sections describe each of the specific sampling methods that can be accomplished using direct push techniques, along with details specific to each method. While SESD currently uses the sample tooling described, tooling of similar design and materials is acceptable. If gravel, concrete, etc. is present at or near the surface, it should be removed before the sample is collected. The depth measurement for the sample begins at the top of the soil horizon, immediately following any removed materials. Turf grass is not typically removed prior to sampling with these devices. 5.2 Large Bore@ Soil Sampler The Large BoreO (LB) sampler is a solid barrel direct push sampler equipped with a piston -rod point assembly used primarily for collection of depth -discrete subsurface soil samples. The sample barrel is approximately 30-inches (762 mm) long and has a 1.5-inch (38 mm) outside diameter. The LBO sampler is capable of recovering a discrete sample core 22 inches x 1.0 inch (559 mm x 25 mm) contained inside a removable liner. The resultant sample volume is a maximum of 283 mL. After the LBO sample barrel is equipped with the cutting shoe and liner, the piston -rod point assembly is inserted, along with the drive head and piston stop assembly. The assembled sampler is driven to the desired sampling depth, at which time the piston stop pin is removed, freeing the push point. The LBO sampler is then pushed into the soil a distance equal to the length of the LBO sample barrel. The probe rod string, with the LBO sampler attached, is then removed from the subsurface. After retrieval, the LBO sampler is then removed from the probe rod string. The drive head is then removed to allow removal of the liner and soil sample. 5.3 Macro -Core@ Soil Sampler The Macro-CoreO (MC) sampler is a solid barrel direct push sampler equipped with a piston -rod point assembly used primarily for collection of either continuous or depth - discrete subsurface soil samples. Although other lengths are available, the standard MCO sampler has an assembled length of approximately 52 inches (1321 mm) with an outside diameter of 2.2 inches (56 mm). The MCO sampler is capable of recovering a discrete sample core 45 inches x 1.5 inches (1143 mm x 38 mm) contained inside a removable liner. The resultant sample volume is a maximum of 1300 mL. The MCO sampler may be used in either an open -tube or closed -point configuration. Although the SESD Operating Procedure Page 18 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY MC® sampler can be used as an open -barrel sampler, in SESD usage, the piston point is always used to prevent the collection of slough from the borehole sides. 5.4 Dual Tube Soil Sampling System The Dual Tube 21 soil sampling system is a direct push system for collecting continuous core samples of unconsolidated materials from within a sealed outer casing of 2.125-inch (54 mm) OD probe rod. The samples are collected within a liner that is threaded onto the leading end of a string of 1.0-inch diameter probe rod. Collected samples have a volume of up to 800 mL in the form of a 1.125-inch x 48-inch (29 mm x 1219 mm) core. Use of this method allows for collection of continuous core inside a cased hole, minimizing or preventing cross -contamination between different intervals during sample collection. The outer casing is advanced, one core length at a time, with only the inner probe rod and core being removed and replaced between samples. If the sampling zone of interest begins at some depth below ground surface, a solid drive tip must be used to drive the dual tube assembly and core to its initial sample depth. 5.5 Special Considerations When Using Direct Push Sampling Methods Liner Use and Material Selection — Direct Push Soil Samples are collected within a liner to facilitate removal of sample material from the sample barrel. The liners may only be available in a limited number of materials for a given sample tool, although overall, liners are available in brass, stainless steel, cellulose acetate butyrate (CAB), polyethylene terepthalate glycol (PETG), polyvinyl chloride (PVC) and Teflon®. For most SESD investigations, the standard polymer liner material for a sampling tool will be acceptable. When the study objectives require very low reporting levels or unusual contaminants of concern, the use of more inert liner materials such as Teflon® or stainless steel may be necessary. Sample Orientation — When the liners and associated sample are removed from the sample tubes, it is important to maintain the proper orientation of the sample. This is particularly important when multiple sample depths are collected from the same push. It is also important to maintain proper orientation to define precisely the depth at which an aliquot was collected. Maintaining proper orientation is typically accomplished using vinyl end caps. Convention is to place red caps on the top of the liner and black caps on the bottom to maintain proper sample orientation. Orientation can also be indicated by marking on the exterior of the liner with a permanent marker. Core Catchers — Occasionally the material being sampled lacks cohesiveness and is subject to crumbling and falling out of the sample liner. In cases such as these, the use of core catchers on the leading end of the sampler may help retain the sample until it is retrieved to the surface. Core catchers may only be available in specific materials and should be evaluated for suitability. SESD Operating Procedure Page 19 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY However, given the limited sample contact that core -catchers have with the sample material, most standard core -catchers available for a tool system will be acceptable. • Decontamination — The cutting shoe and piston rod point are to be decontaminated between each sample, using the procedures specified for the collection of trace organic and inorganic compounds found in Field Equipment and Decontamination — SESDPROC-205, most recent version. Within a borehole, the sample barrel, rods, and drive head may be subjected to an abbreviated cleaning to remove obvious and loose material, but must be cleaned between boreholes using the procedures specified for downhole drilling equipment in Field Equipment and Decontamination — SESDPROC- 205, most recent version. • Decommissioning — Boreholes must be decommissioned after the completion of sampling. Boreholes less than 10 feet depth that remain open and do not approach the water table may be decommissioned by pouring 30% solids bentonite grout from the surface, or pouring bentonite pellets from the surface, hydrating the pellets in lifts. Boreholes deeper than 10 feet, or any borehole that intercepts groundwater, must be decommissioned by pressure grouting with 30% solids bentonite grout, either through a re-entry tool string or through tremie pipe introduced to within several feet of the borehole bottom. • VOC Sample Collection — Observe precautions for volatile organic compound sample collection found in Section 3 of this procedure. SESD Operating Procedure Page 20 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 6 Split Spoon/Drill Rig Methods 6.1 General Split spoon sampling methods are used primarily to collect shallow and deep subsurface soil samples. All split spoon samplers, regardless of size, are basically split cylindrical barrels that are threaded on each end. The leading end is held together with a beveled threaded collar that functions as a cutting shoe. The other end is held together with a threaded collar that serves as the sub used to attach the spoon to the string of drill rod. Two basic methods are available for use, including the smaller diameter standard split spoon, driven with the drill rig safety hammer, and the larger diameter continuous split spoon, advanced inside and slightly ahead of the lead auger during hollow stem auger drilling. The following sections describe each of the specific sampling methods, along with details specific to each method. If gravel, concrete, etc. is present at or near the surface, it should be removed before the sample is collected. The depth measurement for the sample begins at the top of the soil horizon, immediately following any removed materials. Turf grass is not typically removed prior to sampling with these devices. 6.2 Standard Split Spoon A drill rig is used to advance a borehole to the target depth. The drill string is then removed and a standard split spoon is attached to a string of drill rod. Split spoons used for soil sampling must be constructed of stainless steel and are typically 2.0-inches OD (1.5-inches ID) and 18-inches to 24-inches in length. Other diameters and lengths are common and may be used if constructed of the proper material. After the spoon is attached to the string of drill rod, it is lowered into the borehole. The safety hammer is then used to drive the split spoon into the soil at the bottom of the borehole. After the split spoon has been driven into the soil, filling the spoon, it is retrieved to the surface, where it is removed from the drill rod string and opened for sample acquisition. 6.3 Continuous Split Spoon The continuous split spoon is a large diameter split spoon that is advanced into the soil column inside a hollow stem auger. Continuous split spoons are typically 3 to 5 inches in diameter and either 5 feet or 10 feet in length, although the 5-foot long samplers are most common. After the auger string has been advanced into the soil column a distance equal to the length of the sampler being used it is returned to the surface. The sampler is removed from inside the hollow stem auger and the threaded collars are removed. The split spoon is then opened for sampling. SESD Operating Procedure Page 21 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 6.4 Special Considerations When Using Split Spoon Sampling Methods • Always discard the top several inches of material in the spoon before removing any portion for sampling. This material normally consists of borehole wall material that has sloughed off of the borehole wall after removal of the drill string prior to and during inserting the split spoon. • Observe precautions for volatile organic compound sample collection found in Section 3, Method 5035. SESD Operating Procedure Page 22 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 7 Shelby Tube/Thin-Walled Sampling Methods 7.1 General Shelby tubes, also referred to generically as thin -walled push tubes or Acker thin -walled samplers, are used to collect subsurface soil samples in cohesive soils and clays during drilling activities. In addition to samples for chemical analyses, Shelby tubes are also used to collect relatively undisturbed soil samples for geotechnical analyses, such as hydraulic conductivity and permeability, to support hydrogeologic characterizations at hazardous waste and other sites. If gravel, concrete, etc. is present at or near the surface, it should be removed before the sample is collected. The depth measurement for the sample begins at the top of the soil horizon, immediately following any removed materials. Turf grass is not typically removed prior to sampling with this device. 7.2 Shelby Tube Sampling Method A typical Shelby tube is 30 inches in length and has a 3.0-inch OD (2.875-inch ID) and may be constructed of steel, stainless steel, galvanized steel, or brass. They also typically are attached to push heads that are constructed with a ball -check to aid in holding the contained sample during retrieval. If used for collecting samples for chemical analyses, it must be constructed of stainless steel. If used for collecting samples for standard geotechnical parameters, any material is acceptable. To collect a sample, the tube is attached to a string of drill rod and is lowered into the borehole, where the sampler is then pressed into the undisturbed material by hydraulic force. After retrieval to the surface, the tube containing the sample is then removed from the sampler head. If samples for chemical analyses are needed, the soil contained inside the tube is then removed for sample acquisition. If the sample is collected for geotechnical parameters, the tube is typically capped, maintaining the sample in its relatively undisturbed state, and shipped to the appropriate geotechnical laboratory. 7.3 Special Considerations When Using Split Spoon Sampling Methods Observe precautions for volatile organic compound sample collection found in Section 3, Method 5035. SESD Operating Procedure Page 23 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY 8 Backhoe Sampling Method 8.1 General Backhoes may be used in the collection of surface and shallow subsurface soil samples. The trenches created by excavation with a backhoe offer the capability of collecting samples from very specific intervals and allow visual correlation with vertically and horizontally adjacent material. If possible, the sample should be collected without entering the trench. Samples may be obtained from the trench wall or they may be obtained directly from the bucket at the surface. The following sections describe various techniques for safely collecting representative soil samples with the aid of a backhoe. The depth measurement for the sample begins at the top of the soil horizon. 8.2 Scoop -and -Bracket Method If a sample interval is targeted from the surface, it can be sampled using a stainless steel scoop and bracket. First a scoop and bracket are affixed to a length of conduit and is lowered into the backhoe pit. The first step is to take the scoop and scrape away the soil comprising the surface of the excavated wall. This material likely represents soil that has been smeared by the backhoe bucket from adjacent material. After the smeared material has been scraped off, the original stainless steel scoop is removed and a clean stainless steel scoop is placed on the bracket. The clean scoop can then be used to remove sufficient volume of soil from the excavation wall to make up the required sample volume. 8.3 Direct -from -Bucket Method It is also possible to collect soil samples directly from the backhoe bucket at the surface. Some precision with respect to actual depth or location may be lost with this method but if the soil to be sampled is uniquely distinguishable from the adjacent or nearby soils, it may be possible to characterize the material as to location and depth. In order to ensure representativeness, it is also advisable to dress the surface to be sampled by scraping off any smeared material that may cross -contaminate the sample. 8.4 Special Considerations When Sampling with a Backhoe • Do not physically enter backhoe excavations to collect a sample. Use either procedure 8.2, Scoop -and -Bracket Method, or procedure 8.3, Direct -from - Bucket Method to obtain soil for sampling. • Smearing is an important issue when sampling with a backhoe. Measures must be taken, such as dressing the surfaces to be sampled (see Section 2.3), to mitigate problems with smearing. SESD Operating Procedure Page 24 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011 COPY Paint, grease and rust must be removed and the bucket decontaminated prior to sample collection. Observe precautions for volatile organic compound sample collection found in Section 3, Method 5035. SESD Operating Procedure Page 25 of 25 SESDPROC-300-R2 Soil Sampling Soil Sampling(300)_AF.R2 Effective Date: December 20, 2011