3 - 495_DotAve_DrillerSOW_8-27-24_Revised_3.pdf

U.S. Department of Transportation Volpe National Transportation Systems Center

Supplemental Phase II Environmental Site Assessment, Risk-Based Cleanup and Disposal Plan, and Risk Characterization Sampling at 495 Dorchester Ave

495 Dorchester Avenue, Boston, MA 8/22/24

STATEMENT OF WORK

1.0 INTRODUCTION

Under an Interagency Agreement, the U.S. Department of Transportation John A. Volpe National Transportation Systems Center (Volpe Center) is providing support to the U.S. Environmental Protection Agency (EPA) Targeted Brownfields Assessments (TBA) program. As part of this effort, a Supplemental Phase II Environmental Site Assessment, a Risk-Based Cleanup and Disposal Plan, and a Risk Characterization including drilling and sampling activities will be conducted at 495 Dorchester Avenue in Boston, MA. This contract is specifically for drilling activities.

2.0 BACKGROUND

Assessment activities that took place from the 1990s to present have identified contaminants in soil and/or groundwater at the Site, including polychlorinated biphenyls (PCBs), metals, petroleum hydrocarbons, chlorinated volatile organic compounds (CVOCs), semivolatile organic compounds (SVOCs), and cyanide. Light non-aqueous phase liquid (LNAPL) has also been encountered in groundwater monitoring wells at the Site. Site assessment activities indicated that contaminants have impacted non-native fill materials at the Site and in some cases the underlying peat and native clay soils. CVOC and cyanide impacts are present in groundwater. Additional investigations have been conducted from 2022 to present to delineate the extents of TSCA-regulated PCBs in soil across portions of the Site (OTD D2 Title LLC, 2024).

The purpose of the investigation is to collect soil and groundwater samples to evaluate data gaps associated with future regulatory closure, to collect soil and groundwater samples to evaluate risk remaining following Site redevelopment, and to collect soil samples for waste disposal characterization to support the off-site reuse/disposal of impacted soils.

Site location and topographic maps are included as Attachments 1 and 2 respectively.

3.0 TASKS TO BE PERFORMED

The investigations include the Contractor tasks listed below. The contractor must be a Massachusetts licensed driller. The Contractor shall conduct all work in accordance with Federal, State and local requirements. Where inconsistencies exist, the Contractor shall follow the most stringent requirement.

3.1 Work Plan

The Contractor shall submit a simplified draft Work Plan within 5 business days after attending a kickoff meeting with the Volpe Center representatives that addresses the project requirements below.

The Work Plan shall detail the technical approach and schedule for conducting all activities as required and described below. To assist with preparation of the Work Plan, the contractor shall thoroughly review any Government-furnished information provided to them.

In addition, the work plan shall also identify any required permits needed to perform the work and the contractor shall be responsible for obtaining those permits as required. Copies of the permits shall be attached to the work plan as an appendix. If no permits are required, the Work Plan shall cite the justification for this.

Additional components of the Work Plan are the Site Safety and Health Plan (SSHP), which shall include personnel health and safety precautions to be followed. The work plan shall also include a Risk Management Plan that identifies major risks and hazards on each site and discusses ways to minimize these risks.

An outline summarizing the required content of the work plan is shown below:

1.) Technical Approach

a. Methods and procedures, including equipment, methods, and materials to be used, for activities described below 2.) Site Safety Health Plan (SSHP) 3.) Risk Management Plan

a. Identification of major risks

b. Risk mitigation plan

4.) Appendix

a. Copies of any state or local permits required to perform activates described herein or other supplemental information The Contractor should expect a 5 business day Volpe Center review period between submission of the Draft Work Plan and receipt of Volpe Center comments. The Volpe Center and the Contractor shall meet to discuss any comments and changes, if necessary. The Contractor shall make the changes and submit a Final Work Plan within 5 business days of the receipt of comments.

3.2 Soil Boring Advancement

The contractor will advance soil borings as shown in Attachment 3. Most soil borings will be advanced using direct-push (i.e., Geoprobe) drilling techniques to depths up to approximately 46 feet below ground surface (ft. bgs) or to drilling equipment refusal, whichever is encountered first.

Soil borings are proposed to be advanced using hollow-stem auger (HSA) drilling techniques in locations where monitoring wells are proposed to be installed (shown in Attachment 4). In these locations, soil samples will be collected continuously using 2-foot split-spoon samplers prior to monitoring well installation. Additionally, if Geoprobe drilling techniques encounter difficulty reaching their specified drilling depths, certain additional portions of the soil sampling scope can be achieved using an HSA drill rig. In order to complete the soil borings in a timely fashion, if an HSA drill rig is not already on-site, the contractor shall be responsible to get one on-site within 48 hours of the Volpe on-site representative identifying the need. Some locations may require the advancement of a second boring immediately adjacent to the first to obtain additional soil volume for the proposed sample analyses.

If a subcontractor is needed, the prime contractor must have a representative in-person on-site at all times.

Prior to the start of the work, Volpe will:

• Notify Call-Before-You-Dig services

• Conduct a ground penetrating radar (GPR) survey

• Survey and mark out drilling locations

The presence of buried structures may require the sampling locations proposed in this plan to be modified but the number of borings will remain the same.

3.3 Soil Sample Collection

Volpe will be responsible for collecting soil samples at continuous intervals starting from immediately below the cap. Number of samples and sample intervals will vary between borings and will be directed by onsite Volpe personnel. .

3.4 Groundwater Monitoring Well Installation

Permanent groundwater monitoring wells will be installed using an HSA drill rig as shown in Attachment 3 and 4 and in accordance with Volpe SOP-013 Monitoring Well and Piezometer Installation. The permanent groundwater monitoring wells will be constructed of lengths of bottom plugged, 2-inch diameter Schedule 40 polyvinyl chloride (PVC) slotted screen, followed by lengths of solid PVC riser to grade. The monitoring wells intended to investigate potential CVOC impacts will be constructed using a standard 0.01-inch slot screen. A 0.20-inch slot screen will be used to construct the monitoring wells intended to investigate the extent of LNAPL. The monitoring wells will be installed to the specified depth, and a silica sand pack will be constructed around the well screen to approximately one foot above the top of the well screen. A bentonite seal will be installed starting 1 foot above the sand pack and will extend to at least 1 foot above the groundwater table, followed by additional silica sand to approximately 6 inches below grade.

Monitoring wells will be finished with a flush mounted road box set in a concrete pad at grade.

Groundwater monitoring wells will be set at depths and with screen intervals as specified by Volpe field staff, between 10 and 25 feet below ground surface. Following installation, Volpe will gauge the newly installed groundwater monitoring wells to determine depth of product, if present, depth to water, and depth to the bottom of the monitoring well.

3.5 Monitoring Well Development

Following gauging, the contractor will develop the monitoring wells in accordance with Volpe SOP-014 Monitoring Well Development to remove fine grained sediment from the well screen and to re-establish the natural hydraulic flow conditions of the soil outside the borehole that may have been disturbed during well installation. The wells will be developed until the water column is free of visible sediment or until at least three well volumes of water have been removed from the well.

If the well is pumped to dryness or near dryness, the water table should be allowed to sufficiently recover before the next development period is initiated. Groundwater purged from the wells will be containerized as IDW in USDOT-approved and Volpe-provided 55-gallon drums.

3.6 Decontamination

During drilling activities in the TSCA Area, drilling equipment will be decontaminated between soil boring locations utilizing d-limonene, Capsur (or equivalent). Volpe will collect one set of rinse blanks (i.e., one rinse blank sample per drill rod) for every 20 soil borings advanced within the TSCA Area. The samples will ensure decontamination procedures are sufficiently effective and will be modified on an as needed basis if PCBs are detected in the rinse blank samples.

Following completion of the investigation in the TSCA Area, drilling equipment will be decontaminated using d-limone, Capsur (or equivalent), and Volpe will collect PCB wipe samples for laboratory analysis (i.e., one wipe sample per drill rod). The samples will be collected prior to releasing the equipment from the Site to confirm that PCBs were effectively removed from the equipment. During drilling activities in the Non-TSCA Area, drilling equipment will be decontaminated between each soil boring with Liquinox and water. To prevent potential cross-contamination between the TSCA and Non-TSCA Areas, all tooling and equipment must be decontaminated after use in the TSCA Area before being used in the Non-TSCA Area.

Decontamination will be performed in accordance with Volpe SOP-018 Field Sampling Equipment Decontamination.

3.7 Investigation-derived Waste (IDW) Management

IDW generated during the completion of this investigation, consisting of soil, groundwater, decontamination water, and solid waste (i.e., PPE, decontamination equipment, polyethylene sheeting, etc.), will be stored on Site in 55-gallon DOT drums, cubic yard totes, and/or roll-off containers, as necessary and in accordance with Volpe SOP-020 Management of Investigation Derived Waste. These containers will be supplied by the Volpe Center. IDW from the 495 Dorchester Avenue portion of the Site. TSCA and non-TSCA wastes will be segregated and containerized separately as follows:

o 495 Dorchester Avenue – TSCA waste o 495 Dorchester Avenue – Non-TSCA waste

Based on the IDW sample results, the Licensed Site Professional (LSP) will prepare the necessary waste profiles and associated documentation to support the off-site disposal of the IDW in accordance with Volpe SOP-021 Hazardous Waste Disposal and Shipment Oversight.

3.8 Demobilization

Following sample collection, completed borings shall be backfilled by the Contractor to surface grade using appropriate materials (such as clean sand) and equipment shall be appropriately removed from the site. Waste shall be handled by separate Contractor in accordance with Volpe SOP-020 Management of Investigation Derived Waste, included in Attachments 5.

3.9 Site Close-out

The Contractor shall provide a brief closeout email, briefly detailing the work completed.

4.0 DELIVERABLES

The Contractor shall prepare the following required deliverables in the quantities described in Table 1 below:

Table 1 - Deliverable Schedule and Details Deliverable Name Format # Copies Date Due/ Recipient

Draft Work Plans Electronic; MSWord* 1 10 business days after kickoff meeting with Volpe; send to technical point of contact (TPOC) and altPOC

Final Work Plans Electronic MSWord*;

Electronic .pdf

5 business days after receipt of govt comments; send electronic copies to TPOC and altPOC

Site Close-out Email Electronic 1

10 business days after site demobilization

5.0 SCHEDULE

The Contractor shall work with Volpe to prepare a schedule for completing the above-described tasks in this SOW and shall include it with their technical proposal. The Government would like this work completed as soon as possible. The period of performance for this effort shall be from date of award to December 31, 2024 with the field work being completed as soon as possible after contract award. Approximate work hours are from 8:00 a.m. to 4:30 p.m. Monday through Friday.

There is to be no work on the weekends, Government holidays, or outside of set work hours unless approved and coordinated with the Volpe Center TPOC. In consideration of the EPA TBA project locations and contract period of performance, schedule delays or impacts stemming from inclement or extreme weather will be evaluated as needed.

6.0 TRAVEL

Contractor travel may be required in execution of contract tasks. All travel costs shall be built in and included in the pricing of line items for which travel may be required and in total fixed price amount.

7.0 PROJECT COORDINATION AND SITE ACCESS

The Contractor shall coordinate all activities and access through the Technical Contracting Officers Representative (TCOR).

8.0 COR

TBD

9.0 Government Furnished Information (GFI)

1. Site Location

2. Topographic Map

3. Soil Boring Locations

4. Groundwater Monitoring Well Locations

5. Volpe SOPs

6. Example Boring Logs

Attachment 1 Site Location

Figure 1: Site Location

Attachment 2 Topographic Map

Site Boundary (Approximate)

0 75 150 225 300 Feet

Notes:

1) Groundwater flow direction is drawn as described in Phase I Environmental Site Assessment, 495 Development Area (VERTEX, April 2024).

2) Groundwater flow "varies and is multi-directional due to mounding in the vicinity of the property boundary between the former 511 and 475 Dorchester Avenue properties" (VERTEX, April 2024).

Figure 2 Topographic Map

Site Specific Quality Assurance Project Plan

On The Dot Development 495 Dorchester Avenue and 65 Ellery Street

South Boston, MA

U.S. Department of Transportation Volpe National Transportation Systems Center

July 2024

Spatial Reference:

NAD 1983 2011 StatePlane Massachusetts Mnld FIPS 2001 FtUS Upper Left: 774958.97E 2946817.45N ft

Sources: Maxar, nearmap, Sources: Esri, Airbus DS, USGS, NGA, NASA, CGIAR, N Robinson, NCEAS, NLS, OS, NMA, Geodatastyrelsen, Rijkswaterstaat, GSA, Geoland, FEMA, Intermap and the GIS user community, Esri, TomTom, Garmin, SafeGraph, GeoTechnologies, Inc, METI/NASA, USGS, EPA, NPS, USDA, USFWS, USGS The National Map: National Boundaries Dataset, 3DEP Elevation Program, Geographic Names Information System, National Hydrography Dataset, National Land Cover Database, National Structures Dataset, and National Transportation Dataset; USGS Global Ecosystems; U.S. Census Bureau TIGER/Line data; USFS Road data;

Natural Earth Data; U.S. Department of State HIU; NOAA National Centers for Environmental Information

North End

Boston

Boston University School of Medicine

Bay Village

Neponset River Waterfront

South Station

South Boston

South End

JFK - Umass Station

Dorchester Bay

South Boston Waterfront

Telegraph Hill

D Street - West Broadway

Financial District

Boston Common

Site Location

0 0.25 0.5 Miles

Legend

Site Boundary (Approximate)

Groundwater Flow Direction

Attachment 3 Soil Boring Locations

1 STORY BRICK & CONC.

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5N-12

& PAC CYANIDE

& TOTAL VOCs

& TOTAL CYANIDE

& TOTAL VOCs & SPLP VOCs

& TOTAL VOCs

& PAC CYANIDE

& TOTAL VOCs & SPLP VOCs & PAC CYANIDE

& PAC CYANIDE

& TOTAL CYANIDE

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& DISPOSAL

SCALE:1" = 40'

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NOTES:

1) THE PROPERTY LINES SHOWN ON THIS PLAN ARE BASED UPON AN ACTUAL FIELD SURVEY

CONDUCTED BY VHB, INC. BETWEEN JULY & AUGUST 2019 FROM DEEDS AND PLANS OF

RECORD.

2) THE EXISTING CONDITIONS SHOWN ON THIS PLAN WERE DEVELOPED FROM A COMBINED

EFFORT OF AERIAL PHOTOGRAMMETRIC MAPPING BY TOPOFRAPHICS, INC., BASED ON

AERIAL PHOTOGRAPHS TAKEN ON JULY 29, 2019, AND AUGMENTED BY AN

ON-THE-GROUND SURVEY PERFORMED BY VHB BETWEEN JULY & AUGUST 2019.

3) HORIZONTAL DATUM IS BASED ON MASS. GRID SYSTEM, NAD 1983.

LEGEND:

PROPERTY BOUNDARIES

TSCA INTERIM USE BOUNDARY

PROPOSED DEVELOPMENT BOUNDARIES

495 RAP AREA

20-FOOT GRID LINE

EXISTING BUILDING

TOTAL LEAD ANALYSIS

TCLP LEAD ANALYSIS

TOTAL BARIUM ANALYSIS

TCLP BARIUM ANALYSIS

TOTAL CHROMIUM ANALYSIS

PAC CYANIDE ANALYSIS

TOTAL CYANIDE ANALYSIS

TOTAL VOC ANALYSIS

TOTAL VOCs & SPLP VOC ANALYSIS

MCP (PLUS PAC CYANIDE) ANALYSIS

TPH ANALYSIS

DISPOSAL SAMPLE ANALYSIS

PROPOSED SOIL BORING LOCATION

PROPOSED SOIL BORING LOCATION (PENDING RESULTS)

EXISTING SOIL BORING LOCATION (FOR REFERENCE) CHARACTERIZATION

RISK ANALYSIS

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Attachment 4 Groundwater Monitoring Well Locations

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15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

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FD-24RR

FD-23RR

GT-4R FD-30R

ALTA-5

ALTA-4

GT-5

MW-6R

MCA-3

MW-14

MCA-7R

FD-31RR

MCA-4

FD-33

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MW-14DR

MW-19D

MW-11D

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VOC ANALYSIS ONLY

VOC ANALYSIS ONLY

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Figure 5: 495 Dorchester Avenue Groundwater Monitoring Well Locations

Attachment 5 Volpe SOPs

SOP 010 – Direct Push Technique Drilling Page 1 of 3

1.0 Introduction

This Volpe SOP identifies and describes the procedure, protocols, control, and requirements for sampling subsurface soil using direct push technique (DPT) drilling technology. DPT drilling is primarily used to investigate shallow to intermediate depths (<50 feet [ft] below grade surface [bgs]). Soil cores are collected and retrieved using a liner (e.g., MacroCore sampler) inside a hollow barrel (e.g., probe rod). State-specific subsurface investigation pertaining to site remediation and drilling permits should be reviewed prior to planning the work. This SOP does not discuss using DPT technology to install a monitoring well.

2.0 Definitions

1. BGS – below ground surface

2. Catcher/retainer – end piece inserted into the drive point of the sampler to help retain loose material in the sampler

3. DPT – direct push technique; uses direct force to advance a sampling device

4. Drill string – the extension rods and sampler

5. Extension rods – hollow steel rods used to advance and retrieve sampler

6. Impact head – part of the direct-push rig which transfers energy to the drill string

7. Push depth – depth bgs of the sampler

8. Sampler – device used to collect subsurface soil

3.0 Equipment

1. Personal Protective Equipment (PPE) for the appropriate hazard level as described in the site-specific Health & Safety Plan (HASP)

2. HASP, Sampling/Analysis Plan (SAP), site drawings, and documents related to the sampling investigation

3. Field notebook and indelible marker or pen

4. Volpe Monitoring Well Construction and Boring Log

5. Marking flags

6. Photoionization Detector (PID)

7. Camera

8. Tape measure

9. Polyethylene sheeting

10. Sampler, extension rods, catcher, and liners

11. Sample containers (appropriate number, type, and preservatives) with labels and chain of custody; sample cooler with ice

Standard Operation Procedure (SOP) Prepared: H. Talbot- Wendlandt

Title: Direct Push Technique Drilling Reviewed: C. Fry

No: 010 Ver. 1.0 Date: 01/09/23 Approval: M. Heimgartner

SOP 010 – Direct Push Technique Drilling Page 2 of 3

12. Appropriate sampling materials, which may include: metal spoons and bowls, trowel, and/or other tools

13. Decontamination equipment, including paper towels, detergent, and water

4.0 Procedures

1. Prior to mobilization, inspect all field equipment to ensure that all components are present, in good condition, and protected from potential sources of contamination.

2. Review documents pertaining to the sampling investigation including but not limited to the HASP, SAP, and site drawings to prepare for the sampling event. Determine the sampling technique(s) that will be deployed and the equipment that will be used.

3. Coordinate site access and perform utility clearance in accordance with Volpe SOP-002.

4. Once onsite, don (put on) the appropriate PPE per the site-specific HASP.

5. Review each proposed borehole location with the drill operator and mark locations with flags. Take photographs of the site and of all borehole locations with any nearby utility markings. Discuss the need to hand clear select borehole locations with the drill operator.

6. Inspect the drilling equipment and any contractor-supplied materials with the drill operator. Ensure that sample liners are kept in a sealed or clean environment and that they are an appropriate material. Disposable polymer liners are acceptable for most purposes, though Teflon® or stainless steel liners may be required when the study objectives require very low reporting levels or if there are unusual contaminants of concern. Some of these liners (e.g., stainless steel liners) are not disposable and should be decontaminated between each use.

7. If necessary, install safety cones, caution tape, and/or barriers around the drilling location to secure the work area.

Identify a safe location and place polyethylene sheeting down within the work area.

8. The drill operator will move the drill rig to the drilling location. The drill operator should stabilize and level the rig if possible, and they should always adjust the rig slowly so that the rig does not shift or contact any overhead utilities/structures. The drill operator will assemble the sampler, attach the liner to the cutting head, insert the liner into the outer tube, and screw the cutting head to the outer tube. Then attach the impact head to the top of the outer tube. Once depth is reached, the drill operator will retract the drill string with the soil cores and turn them over to the field personnel.

9. When the soil cores are received, be sure to note and maintain the proper orientation by writing on the liner with a permanent marker. Be sure to keep soil cores out of direct sunlight, rain, or excess ambient air temperatures while performing soil sample collection and soil logging.

10. Collect soil samples from the core, following directions in the sampling plan. Be sure to record the time of sampling, ease of drilling, length of recovered core, push depth, soil lithology, and any other notable characteristics in the Volpe Monitoring Well Construction and Boring Log (SOP Attachment 1) per Volpe SOP-003.

11. If the borehole is to be abandoned, consult planning documents and state regulations for specifications. Borings may be converted into monitoring wells (see Volpe SOP-013 for monitoring well installation procedures), but it is not recommended as well installation can be difficult in DPT-drilled holes.

12. Decontaminate all equipment used. Any small tools or equipment should be decontaminated in accordance with Volpe SOP-018. The cutting shoe and rod may be cleaned with high-pressure water or steam.

13. Repeat steps 5-12 for all additional drilling locations.

14. Drill cuttings and excess sample material shall be handled as IDW per Volpe SOP-020 investigation-derived waste and managed in accordance with the SAP.

SOP 010 – Direct Push Technique Drilling Page 3 of 3

5.0 Quality Assurance and Control (QA/QC)

The Volpe field staff onsite for sample collection are responsible for QA/QC, which includes ensuring that all steps of the SOP are correctly performed and that the sample collection is performed in line with the site-specific sampling plan.

6.0 Limitations and Precautions

SOPs regarding site access, utility clearance, equipment decontamination, and specific sampling procedures should be consulted prior to sampling. State-specific subsurface investigation pertaining to site remediation, drilling permits, and monitoring well installation should be reviewed prior to planning the work.

7.0 References

Environmental Protection Agency: Region 4 Laboratory Services and Applied Science Division, 2020. Soil Sampling.

New Jersey Department of Environmental Protection, 2022. Field Sampling Procedures Manual: Section 6.4.

SOP 011 – Hollow Stem Auger Drilling Page 1 of 3

This Volpe SOP identifies and describes the procedures and methods required to perform field oversight of hollow-stem auger (HAS) drilling. This procedure includes the minimum required steps and quality checks that field personnel shall follow when using this drilling technique.

HAS drilling is appropriate for use in subsurface unconsolidated deposits. The augers are advanced by rotation and the drill cuttings are brought to the surface by travelling up the exterior of the auger flights in a screw-like manner. HSAs allow for boring casings or monitoring wells to be installed inside the hollow stem, helping to stabilize the borehole from collapsing. In situations where boreholes cannot be stabilized, conventional drilling methods may not be adequate for drilling soil borings or installing monitor wells.

When planned depth is reached, the casing and screen are placed inside the HAS and the flights are individually removed and the annular space around the well is filled with filter pack and grout, as needed. Samples can be collected by removing the drilling attachment and advancing a soil sampling device such as a split-spoon/split-barrel sampler.

The Volpe project manager is responsible for coordination with necessary subcontractors. The Volpe field specialist is responsible for implementing all field activities in accordance with the SOP, site-specific Health and Safety Plan (HASP), Sampling and Analysis Plan (SAP), or other site planning documents. State-specific subsurface investigation regulations pertaining to site remediation and drilling permits should be reviewed prior to planning the work.

2.0 Equipment

1. Personal Protective Equipment (PPE) for the appropriate hazard level as described in the site-specific HASP

2. HASP, SAP, site drawings, and documents related to the sampling investigation

3. Field notebook

4. Volpe Monitoring Well Construction and Boring Log

5. Engineers Ruler or measuring tape

6. Indelible marker or pen

7. Sample cooler with ice and sample containers (appropriate number, type, and preservatives)

8. Aluminum foil, glass jars, or other equipment for soil headspace screening is planned

9. Chain of custody

10. Polyethylene sheeting

11. Decontamination supplies

12. Camera

13. Water level meter, if required

14. Photoionization Detector (PID), if required.

Standard Operation Procedure (SOP) Prepared: E. Starr

Title: Hollow Stem Auger Drilling Reviewed: C. Fry

No: 011 Ver. 1.0 Date: 01/09/23 Approval: M. Heimgartner

SOP 011 – Hollow Stem Auger Drilling Page 2 of 3

3.0 Procedures

3.1 Mobilization and Set Up

1. Review documents pertaining to the sampling investigation including but not limited to the HASP, SAP, and site drawings to prepare for mobilization.

2. Prior to mobilization, inspect all field equipment to ensure that all components are present, in good condition, and protected from potential sources of contamination.

3. Don (put on) PPE as described in the site-specific HASP.

4. Drill operators and field specialists should be familiar with the locations of utilities in the area, both overhead and underground. For all subsurface explorations or excavations using any method, adherence to regulations that require utility notification (e.g., Dig Safe® or Call Before You Dig) is mandatory (refer to Volpe SOP-002).

3.2 Field Procedures

5. Once mobilized to the site, field personnel will review the SAP with drill operators and evaluate each proposed borehole location for potential hazards or obstructions. If borehole locations must be moved due to the presence of hazards or obstructions, suitable alternative drilling locations should be identified and confirmed with the project lead or manager. This must be recorded in the field notebook.

6. Inspect and verify all drilling equipment and any sub-contractor-supplied materials are in compliance with SAP and technical specifications.

7. If necessary, install safety cones, caution tape, and/or barriers around the drilling location to secure the work area. Identify a safe location and place polyethylene sheeting down within the work area.

8. Drilling of the shallow depths (up to 6 feet) should be completed slowly to verify the absence of any potential unmarked utilities or obstructions. Split-spoon sampling may be collected at the ground surface, depending on project SAP. Split-spoon sampling shall be conducted in accordance with Volpe SOP-008.

9. Perform HAS drilling for subsurface soil sampling and/or groundwater well installation, as needed. For well installation, refer to Volpe SOP-013.

10. The field specialist shall observe and document the drilling operation and ensure compliance with the SAP.

11. All pertinent information shall be recorded during observation, including the ease/difficulty of the drilling, any refusals or encountered objects, approx. rotation speeds, hard drilling, lost drilling fluids, air monitoring results (if applicable), and any potential indications of contamination in drill cuttings or drill fluids per Volpe SOP-001.

12. Once the borehole is cleaned out, a split-spoon soil sample may be collected (Volpe SOP 008), or the casing may be advanced further. The field specialist should monitor the integrity of the borehole to ensure the hold has not collapses before collecting a split-spoon sample. This process will be repeated until the targeted depth or drilling refusal is reached.

13. Collect soil samples, following directions in the sampling plan. Record the sample time, depth and other notable characteristics in the Volpe Monitoring Well Construction and Boring Log (SOP Attachment 1) per Volpe SOP-003.

14. Drill cuttings and excess sample material shall be handled as IDW per Volpe SOP-020 investigation-derived waste and managed in accordance with the SAP.

15. If the borehole is to be abandoned, consult planning documents and state regulations for specifications. Borings may be converted into monitoring wells (see Volpe SOP-013 for monitoring well installation procedures).

SOP 011 – Hollow Stem Auger Drilling Page 3 of 3

3.3 Demobilization

16. Prior to final demobilization from the site, the drill rig should be free of gross contamination and decontaminated as necessary.

4.0 Quality Assurance and Control (QA/QC)

The Volpe field specialist onsite for drilling oversight and sample collection is responsible for QA/QC, which includes ensuring that all steps of the SOP are correctly performed and that the sample collection is performed in line with the site-specific sampling plan.

5.0 Limitations and Precautions

Consolidated deposits can create problems with HAS drilling as auger refusal can be difficult to work around. HAS drilling can result in a large volume of investigation derived waste. Additionally, HAS drilling can be slower than other drilling methods such as sonic and direct-push, limiting continuous sampling.

All personnel involved with case and wash drilling and this SOP should be familiar with the site-specific hazards included in the HASP. All personnel shall be familiar with emergency procedures when a drill rig is in use. The Drill Operator should be licensed per state regulations

6.0 References

ASTM, 2018. ASTM D5784: Standard Guide for Use of Hollow-Stem Augers for Geoenvironmental Exploration and the Installation of Subsurface Water Quality Monitoring Devices, 2018

NJDEP. 2005. Field Sampling Procedures Manual. August 2005.

SOP 013 – Monitoring Well and Piezometer Installation Page 1 of 4

This Volpe SOP identifies and describes the procedure, protocols, controls, and requirements for installing permanent groundwater monitoring wells and piezometers. This SOP is to be used whenever a monitoring well or piezometer is to be installed.

Monitoring wells are designed and installed for the purpose of collecting groundwater samples, measuring groundwater elevations, and obtaining hydrogeological information about the aquifer beneath an area of investigation. Piezometers are installed only for measuring groundwater elevations.

The process of monitoring well and piezometer installation involves drilling boreholes through various types of geologic formations, which may require different drilling methods and well construction details. A typical well consists of installing a vertical pipe with a screened portion at the bottom into a borehole, and the piping is then surrounded by a filter pack (e.g., coarse sand), bentonite, and/or grout. Groundwater wells should be designed to withstand the duration of the monitoring program.

This SOP addresses monitoring well and piezometer installation and does not discuss procedures for drilling boreholes.

Separate Volpe SOPs that address drilling (Volpe SOP-010, Volpe SOP-011, and Volpe SOP-012) should be consulted.

2.0 Definitions

1. Annular Space – space between the well casing or well screen and the side of the boring

2. Bentonite Seal – well construction material made of a clay that expands with water to protect the annular space directly above the screened interval

3. Casing – solid, tubular well piping that provides support to the well

4. Filter pack – filter media (typically coarse sand) placed in the annular space around the well screen to prevent fine particles from entering and fouling the well screen

5. Grout – mixture of water, cement, and sand which hardens to fill and reinforce the annular space below the ground surface

6. Monitoring Well – a well used to measure and monitor groundwater properties and to collect groundwater samples for analysis

7. Piezometer – a well used to measure the elevation of the piezometric surface

8. Standpipe Cover – a vertical cover to enclose the aboveground portion of well casing

9. Surface-mount – when the well casing is flush with the ground elevation and closed with a manhole cover so that none of the well causes an obstruction aboveground

10. Tremie – a narrow, watertight pipe with a hopper at its upper end used for pouring well construction materials into deep borings

Standard Operation Procedure (SOP) Prepared: J. Klaybor

Title: Monitoring Well and Piezometer Installation Reviewed: C. Fry

No: 013 Ver. 1.0 Date: 01/09/23 Approval: M. Heimgartner

SOP 013 – Monitoring Well and Piezometer Installation Page 2 of 4

11. Well screen – slotted, tubular well piping that allows water, but not filter pack material, to enter into the well

3.0 Equipment

1. Personal Protective Equipment (PPE) for the appropriate hazard level as described in the site-specific Health & Safety Plan (HASP)

2. HASP, Sampling and Analysis Plan (SAP), well designs, site drawings, and documents related to the installation activity

3. Well installation rig with qualified and (if required) licensed operators

4. Plastic sheeting

5. Weighted tape measure, water level indicator, or oil/water interface probe

6. Well screen and casing piping (provided by subcontracted well driller)

7. Tremie pipe (provided by subcontracted well driller)

8. Filter pack materials (provided by subcontracted well driller)

9. Bentonite (provided by subcontracted well driller)

10. Grout (provided by subcontracted well driller)

11. Standpipe or well manhole cover (provided by subcontracted well driller)

12. Concrete (provided by subcontracted well driller)

13. Expandable plug (provided by subcontracted well driller)

14. Padlock and key

15. Identification label

16. Camera

17. A device for collecting Global Positioning System (GPS) coordinates

18. Field notebook

19. Volpe Well Construction and Boring Log

4.0 Procedures

1. Obtain necessary permits and drill operator licenses as required by local or state regulations.

2. Review documents pertaining to the sampling investigation including but not limited to the HASP, SAP, and site drawings to prepare for the well installation.

3. Prior to mobilization, inspect all field equipment to ensure that all components are present, in good condition, and protected from potential sources of contamination.

4. Put on PPE as described in the site-specific HASP.

5. Confirm that underground utilities that may be present at the site do not conflict with the proposed monitoring well or piezometer installation location.

6. The drilling subcontractor will mobilize the drill rig over the well installation area and stabilize the rig. Check above for overhead utilities before the drilling subcontractor raises the mast. Put physical barriers (e.g., safety cones, caution tape, safety rails) around the work area, identify an area to safely deploy plastic sheeting, and lay down plastic sheeting to secure the area. All personnel should know where the kill switch(s) is(are) located on the drill rig in case of emergencies.

SOP 013 – Monitoring Well and Piezometer Installation Page 3 of 4

7. Review the proposed borehole depth and well construction details with the drilling subcontractor before the borehole is advanced to the designated depth. Once the borehole is advanced to the desired depth, use a weighted tape measure to confirm the depth. If required, log and screen soils during the borehole advancement per Volpe SOP-003 and record pertinent well installation information in the field notebook per Volpe SOP-001.

8. Ensure the borehole is advanced deep enough to intersect the water table. The proposed well depth and construction details may need to be changed based on field observations such as encountering a confining layer or hitting refusal, but this needs to be communicated with the QA/QC manager, project manager, and/or client before the well is constructed. Any modifications to the well depth and constructions details must be approved by the project manager and client and recorded in the field notebook.

9. Once the desired borehole depth is reached, the well must be constructed per the proposed well construction details or per the approved field change. A typical well is constructed using a nominal length of screened pipe coupled to a nominal length of casing. A cap is added to the bottom of the well to prevent filter pack material from entering the well from the bottom. Well construction materials should be left in the manufacturer’s packaging until needed and care should be taken to ensure the materials do not become contaminated. Ensure the well construction materials match the specifications of the proposed well construction details and local or state regulations.

10. Place at least 6 inches of filter pack directly into the bottom of the boring with a tremie pipe (or directly into the boring for shallow wells).

11. Once the constructed well is placed in the borehole, install filter pack material (e.g., #1 coarse sand) into the annular space around the screen to a depth of at least 2 feet above the top of the screen. Install bentonite/cement grout into the annular space to the top of the borehole (this should be at least 2 feet thick). If the top of the filter pack extends the saturated zone, a layer of at least 1 foot of fine sand (e.g., #00 fine sand) may be used between the filter pack and the bentonite/cement grout. A tremie pipe may be required to install the filter pack, fine sand, and bentonite/cement grout.

12. The well casing should extend at least 2 feet above the ground surface and a standpipe cover should be installed while the grout is semi-fluid. If the well is located in a paved or heavy traffic area where the top of the well needs to be flush with ground level, the well may be surface mounted by installing a monitoring manhole cover. Close the top of the well casing with an expandable plug and cover the area excavated around the casing with concrete.

For above-ground casings in high traffic areas, bumper guards may need to be installed around the well for protection.

13. Place a padlock on the standpipe or manhole cover to secure the well. All well padlocks at the site should be keyed alike.

14. Place a tag indicating the well identification number, screen interval and casing elevation on the well.

15. Complete the Volpe Monitoring Well Construction and Boring Log (SOP Attachment 1) that includes the well identification number, location coordinates, construction date, screened interval, casing elevation (to be completed by a licensed surveyor), well diameter, and a diagram of the well’s construction and lithological conditions.

5.0 Quality Assurance and Control (QA/QC)

The drill rig operator should inspect the rig and drilling equipment prior to beginning work. Well construction materials should be inspected by the contractor prior to installation. The Volpe onsite representative must work with the

SOP 013 – Monitoring Well and Piezometer Installation Page 4 of 4 contractor to ensure that all steps of the SOP are correctly performed and that the wells are constructed according to designs.

6.0 Limitations and Precautions

This SOP does not address all of the hazards and procedures associated with subsurface investigations. SOPs regarding site access, utility clearance, and drilling should be consulted prior to installation of a well. Monitoring wells capture groundwater from a limited area of an aquifer across the entire saturated length of the well screen. Therefore, samples collected from a monitoring well are limited to representing these areas and heterogeneities within the groundwater plume must be carefully characterized. Piezometers should not be used for groundwater sample collection.

7.0 References

EPA Science and Ecosystem Support Division, 2018. Guidance: Design and Installation of Monitoring Wells.

SOP 014 – Monitoring Well Development Page 1 of 4

This Volpe SOP identifies and describes the process for developing monitoring wells. This SOP should be used when installing new wells, when reopening older wells, or when excessive sediment build up is identified in the well (usually via gauging data).

The goal of developing wells is to improve the hydraulic connection between the well screen and the surrounding material by removing sediment which may have been introduced to the well as part of the installation or reopening process. In regions where groundwater flow is too slow to carry suspended sediment, well installation is the primary source of any turbidity associated with monitoring wells. Development can reduce this turbidity and therefore allow samples and measurements taken from the well to represent the site conditions more accurately. Development also removes fluids introduced during drilling or installation.

If samples will not be taken from the well, as is the case with piezometers, development may not be required. There are multiple development methods which are commonly used, including over-pumping (often in conjunction with backwashing) and surging. Bailing is not recommended for well development as it is slow and does not effectively remove sediment. Review of state-specific monitoring well development regulations may be required prior to performing monitoring well development, and a state-licensed well driller may be required to complete the work.

2.0 Definitions

1. Annular space – space between the well casing or well screen and the side of the boring

2. Bentonite seal – well construction material made of a clay that expands with water to protect the annular space directly above the screened interval

3. Monitoring well – a well used to measure and monitor groundwater properties and to collect groundwater samples for analysis

4. Piezometer – a well used to measure the elevation of the piezometric surface

5. PPE – Personal Protective Equipment

6. Surge block – a tool which alternately pushes water down into a well and pumps it out

7. Well screen – slotted, tubular well piping that allows water, but not filter pack material, to enter into the well

3.0 Equipment

1. PPE for the appropriate hazard level as described in the site-specific Health & Safety Plan (HASP)

2. HASP, Sampling/Analysis Plan (SAP), site drawings, well construction log, and documents related to the sampling investigation

Standard Operation Procedure (SOP) Prepared: H. Talbot- Wendlandt

Title: Monitoring Well Development Reviewed: C. Fry

No: 014 Ver. 1.0 Date: 01/09/23 Approval: M. Heimgartner

SOP 014 – Monitoring Well Development Page 2 of 4

3. Submersible pump or surge block

4. Tubing

5. Container to collect and measure water (e.g., 5-gallon bucket, 55-gallon drum, or appropriately sized tank)

6. Water level meter

7. Watch or stopwatch

8. Water quality monitoring instrument(s) to measure pH, temperature, specific conductivity, turbidity, and any other parameters of interest

9. Camera

10. Indelible marker or pen

11. Field notebook

4.0 Procedures

1. Prior to field mobilization, inspect all field equipment to ensure that it is in good working order and protected from potential sources of contamination.

2. Review documents pertaining to the sampling investigation including but not limited to the HASP, SAP, site drawings, and well construction log to prepare for the event. Determine which development method to use:

Features of Aquifer and Well Recommended Method Considerations Shallow well (<25 ft), sand/gravel or high-yield rock aquifer

Over-Pumping and Backwashing

May produce a large volume of discharge water

Highly permeable, homogeneous aquifer Surging May damage non-metallic well screens

3. Coordinate site access and perform utility clearance in accordance with Volpe SOP-002.

4. Once onsite, put on PPE as described in the site-specific HASP.

5. Measure the total well depth and the water level and calculate the current well volume. Compare the measured well depth to the well construction log to determine the potential depth of sediment within the well.

6. Follow the steps for the chosen development method:

Over-Pumping and Backwashing

a. Prepare the pump with tubing long enough to reach the bottom of the well and a container to collect the discharge water.

b. Insert the tubing in the well. It is recommended to begin with the intake placed no deeper than the depth of the bentonite seal. Placing the intake deeper in the well can develop the well more effectively, but in that case the pump operator should be aware and should not draw the water level down below the bottom of the bentonite seal. Doing so could trap air in the formation outside the well screen.

c. Turn on the pump. Pumping should be at a faster rate than the well will typically be pumped for sample collection. Do not pump the water level down below the bottom of the bentonite seal.

d. Turn off the pump and allow water in the line to flow back into the well.

Surging

a. Prepare the surge block with tubing long enough to reach the bottom of the well and a container to collect the discharge water.

b. Begin surging at a slow rate near the water surface within the well. Increase the rate as the depth within the well increases.

SOP 014 – Monitoring Well Development Page 3 of 4

c. Periodically pause to remove the discharge water and associated silt (via pump or bailing) from above the surge block. Ensure that the water level does not drop below the bottom of the bentonite seal, as this could trap air in the formation outside the well screen.

7. Periodically measure and record the pH, temperature, specific conductivity, and turbidity of the discharge water removed from the well. Estimate and record the purge rate and recharge rate using a watch, graduated container, and water level meter.

8. Repeat steps 6-7 until either:

a. Turbidity has stabilized below 5 NTUs (nephelometric turbidity units), and at least two of the following have stabilized: pH, temperature, and specific conductivity. All of these factors are considered to be stabilized when three consecutive readings are within 10% of each other.

OR

b. At least 5 times the initial well volume has been removed. If stabilization does not occur before that volume is removed, the Volpe staff on-site should evaluate whether further development would be advantageous. Wells should not be overdeveloped.

9. Dispose of the discharge water in accordance with applicable regulations and the Investigation Derived Waste (IDW) and Volpe SOP-020. Often, the water can be emptied on-site. If the groundwater contains contaminants, the discharge water should be presumed to contain the same contaminants and should be disposed of appropriately.

10. Decontaminate any equipment used, following Volpe SOP-003.

11. If additional wells are located on-site, repeat steps 5-10 for each well.

5.0 Quality Assurance and Control (QA/QC)

The Volpe staff on-site is responsible for QA/QC, which includes ensuring that all steps of the SOP are correctly performed. If well water will be sampled, ensure that more water is withdrawn from the formation than was introduced throughout the drilling and development processes.

6.0 Limitations and Precautions

A state-licensed well driller may be required to perform this work. Review state regulations pertaining to monitoring well development prior to planning the work.

Over-development can compact fine sediments around the well screen or in the surrounding formation; or it can remove excess formation material, compromising the well seal. The Volpe onsite representative should ensure that the procedure is halted promptly once the well is developed.

This SOP does not address all of the hazards and procedures associated with subsurface investigations. SOPs regarding site access, utility clearance, equipment decontamination, and well installation should be consulted prior to developing a well.

SOP 014 – Monitoring Well Development Page 4 of 4

Massachusetts Department of Environmental Protection, 1991. Standard References for Monitoring Wells: Publication No. WSC-310-91, Section 4.5.

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