2c. DAF PFAS Soil BMPs Playbook.pdf

DEPARTMENT OF THE AIR FORCE

WASHINGTON DC

OFFICE OF THE ASSISTANT SECRETARY

March �, 2025

MEMORANDUM FOR $/M$-&2M�$/)/'&2M�)2$�'58�&&�',675,%87,21�&

FROM: SAF/IEE

1665 Air Force Pentagon Washington, DC 20330-1665

SUBJECT: Best Management Practices for Addressing Contaminated Soils on Military Construction and Facilities Sustainment, Restoration, and Modernization Projects

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NANCY J. BALKUS, P.E., SES

Deputy Assistant Secretary of the Air Force (Infrastructure, Energy, and Environment)

Attachment:

1. Guidance on Best Management Practices for Addressing Contaminated Soils on Military Construction and Facilities Sustainment, Restoration, and Modernization Projects mailto:michelle.brown.36@us.af.mil

Best Management Practices for Addressing Contaminated Soils on Military Construction and Facilities Sustainment, Restoration, and Modernization Projects

Introduction Narrative Background Applicability Project Planning Project Design Considerations and Value Engineering Project Execution References and Resources Acronyms and Abbreviations

Introduction This document provides guidance on best management practices (BMPs) to avoid, minimize, or manage excavated soil (and dewatering liquid) that is contaminated with hazardous substances, pollutants, or contaminants, specifically per- and poly-fluoroalkyl substances (PFAS) at Military Construction (MILCON) and Facility Sustainment, Restoration, and Modernization (FSRM) project sites.

Narrative Managing contaminated soil and dewatering liquids often incurs substantial additional project costs and delays. These issues can be avoided or minimized through early communication between the project team and the Environmental Restoration Program (ERP) office, thorough programming and planning, adjustments in site location or design, and targeted investigation and segregation of contaminated areas.

The Department of the Air Force (DAF) prefers to avoid managing contaminated soil and dewatering liquids, especially when impacted by PFAS, due to the lack of certain and cost-effective disposal methods for PFAS-contaminated materials. In many cases, the savings from avoiding soil and water disposal or treatment, regulatory requirements, and schedule delays far outweigh the cost of modifying project location or design.

If a contaminated site cannot be avoided, a cost-benefit analysis of disposal, treatment, and reuse options is essential when determining the best approach to manage contaminated soil and dewatering liquids. Figure 1 provides a summary of the BMPs that are covered in this document.

Background Recently, PFAS impacted environmental media (e.g. soil, groundwater, surface water, sediments) encountered during MILCON or FRSM activities have led to major schedule delays and cost increases on projects. The Defense Environmental Restoration Program (DERP) manual, DoDM 4715.20, states MILCON or FSRM project funds must be used for management of contaminated materials related to MILCON or FSRM projects. When MILCON or FSRM projects encounter contaminated environmental media during construction or demolition activities (such as soil or concrete excavation and/or dewatering), the project teams must sample, test, and then treat or dispose of the impacted material, depending on the contaminants present and their concentrations. The MILCON and FSRM programs are conducted in accordance with United States Code (U.S.C.) Title 10, Chapter 169 and associated Department of Defense (DoD) directives, instructions, and policies; their processes include project planning, design, and execution.

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Applicability This BMP guidance applies to all Active and Reserve Air Force, Space Force, Air National Guard (ANG), and Base Realignment and Closure (BRAC) locations within the United States and its territories. This guidance pertains to management of soil that is contaminated by historic DAF activities which resulted in releases of hazardous substances, pollutants, or contaminants to the environment. While the guidance is relevant for soils impacted with legacy contaminants such as metals, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and herbicides, special emphasis has been given to management of soils contaminated with PFAS as currently there are no certain and cost-effective management or treatment options for PFAS contaminated soil. The scope of this BMP guidance does not include management of contaminated construction and demolition debris (CDD) such as asphalt, concrete, piping, carpet padding, drywall, etc. Preliminary guidance for the contaminated CDD is disposal in landfills. The landfills used must be certified for either hazardous or non-hazardous waste depending on the contaminants present in the waste and their concentrations.

Project Planning The initial planning phase of a project presents a critical early opportunity to identify the presence of contaminated soil and water in the project footprint and to develop a plan to avoid or minimize generation of contaminated waste. Management of excavated soil and dewatering liquid impacted with hazardous substances, pollutants, or contaminants (e.g., VOCs, SVOCs, metals, pesticides, and herbicides) is challenging and costly. It becomes even more so if the soil is impacted with PFAS as there are currently no cost-effective management or treatment options for PFAS-impacted media. If a project must be located on a site with known contamination, fully identifying and accounting for it during the planning and programming stages can protect the project from schedule delays and budget overruns.

Early Communication and Due Diligence

The DAF regulation and policy documents that govern MILCON and FSRM processes require the project team to identify restrictions on land use that include environmental areas (e.g., wetlands, floodplains, critical habitat), remediation sites, unexploded ordnance areas, and areas with institutional controls when siting a MILCON project or planning an FSRM project.

Planning Design Execution

• Early communication with ERP office regarding potential for contaminants in project footprint.

• Desktop due diligence using GEOBASE and EESOH-MIS to identify potential presence of restoration site.

• Ongoing environmental investigations to influence the project.

• Implication of environmental regulations on project schedule, execution and cost.

• Project relocation to avoid impacted soil / groundwater.

• Design alteration or innovative methods to avoid or reduce earthworks and dewatering.

• Minimize excavation and segregate soils to limit generation of impacted soils.

• Mitigate exposure risks to onsite workers and on-base personnel during project execution.

• Focused investigation and characterization of soil and groundwater in project area.

• Contaminated soil stockpile staging, construction, and management to avoid leaching or runoff to unimpacted areas.

• Management of contaminated soil stockpile through Subtitle C or D landfill disposal or on-site treatment.

• Dewatering and management of contaminated groundwater through on-site treatment.

No cost-effective PFAS treatment or disposal options currently available - Avoidance or minimization is critical

Figure 1 Summary of BMPs

Select a project phase below to navigate to that section of the document ϯ

Early coordination with the ERP office and identification of environmental issues within the project footprint are primary initial steps that can help project teams plan. Some suggested actions are listed below:

• Communicate with the ERP office early during the project planning stage to determine if environmental impacts could be encountered within the project area.

• Consult with Community Planners and research the Air Force Civil Engineer Center (AFCEC) Administrative Record (https://ar.cce.af.mil), State level contaminated sites database, the Enterprise, Environmental, Safety, Occupational Health Management Information System (EESOH-MIS), and publicly available Geographic Information System (GIS) data (i.e., GeoBase layers) or from the GeoBase office to evaluate if the planned project siting could be contaminated. In accordance with Unified Facilities Criteria (UFC) 2-100-01 Appendix D, a constraints map should be prepared using geospatial boundaries of each existing cleanup site being addressed under the CERCLA or Resource Conservation and Recovery Act (RCRA) process and Land Use Controls (LUCs) associated with a cleanup site.

• During the planning phase, the project team should account for ongoing or planned investigations or remedial actions if the project site is located within a DERP site. PFAS Remedial Investigations (RIs), and other aspects of remedial processes are ongoing at many DAF installations. During development of the project, new information may become available, which could change site management needs and approach. Regular communication and coordination with ERP personnel is critical to obtain the most up-to-date information and understand the severity of environmental issues as well as to enable coordination with appropriate regulatory agencies as needed.

• In addition to soil, the project team should also determine the presence of contaminated groundwater. Due to high mobility in groundwater, elevated PFAS concentrations may be present in groundwater far from the original area of release. Additionally, impacts of VOCs and PFAS in groundwater underneath a building may result in exposure to contaminated vapor.

• Based on the findings from communications with the ERP office and desktop research, the project team should use an environmental scoping checklist such as the example included as Enclosure 1 and the Air Force Form 813 (AF Form

813) included as Enclosure 2 for providing environmental impacts analysis. Also, the project team should ensure environmental planning documents (e.g., Environmental Impact Statement [EIS], Environmental Assessment [EA], Categorical Exclusion [CATEX]) include the site contamination issue. Failure to include the environmental impact analysis could extend the National Environmental Policy Act (NEPA) process, as it may be raised during public comment or legal review. If contamination is identified, further discussion is encouraged between the project team and the ERP office regarding potential options for managing and/or treating the contaminated soils and associated dewatering liquid.

Regulatory and Funding Considerations

When a DERP site is identified within a MILCON/FSRM project footprint, it is also important to determine the applicable regulatory framework under which that site is managed. Regulatory requirements will have implications for project cost and schedule. Many DAF installations are listed on the US Environmental Protection Agency (USEPA) National Priority List (NPL) and are governed by Federal Facilities Agreements (FFAs). Depending on the maturity of the program there may be LUCs or other restrictions on activities at different sites across the installation. These sites will add complexity, time, as well as cost to MILCON/FSRM projects. DoDM 4715.20 and DAFI 32.7020 both direct that Environmental Restoration Account (ERA) funds may only be used on remediation sites, and MILCON funds must be used to address contaminants encountered and managed as part of a MILCON project. The DAF regulatory and policy documents governing MILCON and FSRM processes mandate that the project team follow all environmental regulations and requirements applicable to the project site. At a minimum, DAF manages contaminated soil from construction projects in accordance with 42 USC §§ 6901- 6992, Solid Waste Disposal Act and the Resource Conservation and Recovery Act (RCRA) and applicable DoD and DAF policy. (DAFMAN 32-7002, Environmental Compliance and Pollution Prevention). Following are some recommended actions:

• Consult with the ERP office on the site’s regulatory program (State, RCRA, or CERCLA) and status. This will also govern the regulatory criteria applicable to soil and groundwater at the project site as well as contaminant limits that must be achieved for disposal or discharge of media.

• Workplans for fieldwork to disturb or remove contaminated soil or groundwater may require approval from one or more regulatory agencies. Regulatory review and approval timeframes need to be considered in the overall project schedule.

• Performing a focused environmental investigation will help the project team understand the extent of the contamination and adequately estimate costs associated with soil/water management that can be programmed early in the project planning process.

https://ar.cce.af.mil)/ ϰ

Project Design Considerations and Value Engineering Practices for treatment, disposal, and reuse of contaminated soil are well-established and management of such soils is not uncommon. However, managing soils contaminated with PFAS has proven challenging; as there is currently no cost-effective and reliable way to treat or dispose of large quantities of PFAS-impacted soils. It is therefore critical that wherever possible projects should avoid PFAS impacted sites. Following are some recommendations:

• DAF’s preference is to avoid disturbance of contaminated soil. Explore options to relocate the project to an alternate, preferably uncontaminated location.

• In many cases, relocation of a project may not be an option. In these cases, reconsider the design and implement design changes that avoid or minimize earthwork and construction over a contaminated site. The goal is to avoid generating stockpiles of contaminated soils, especially those impacted with PFAS.

• If design change is not feasible, consider construction methods that minimize soil excavation and dewatering and provide opportunities to segregate contaminated soils from uncontaminated soils. Utility projects offer their own opportunities for avoiding management of contaminated materials. The following recommendations should be considered in potential design modifications:

o Use deep foundations instead of shallow foundations such as a pile instead of spread footings.

o Build up instead of out to minimize excavation footprint.

o Use direct-push casing or conduit rather than trenching when installing utilities.

o For utilidors, use precast concrete features when working at the water table whenever possible; this will reduce the amount of water that will need to be pumped and discharged.

o Institute remedial measures for site preparation, such as chemical stabilization or treatment, rather than stockpile/haul/dispose. Get agreement with regulators during design because some alternatives aren’t applicable from a regulatory or technical perspective once the soil is excavated.

o Consider adding a paved area made up of reused, chemically stabilized excavated material, in lieu of disposal.

o For vapor intrusion concerns, consider installing vapor barriers if building above contaminated soil or contaminated shallow groundwater.

o Utilize the Utility Waiver when appropriate for soil, stormwater, and groundwater. The Waiver allows for replacing Petroleum, Oil, and Lubricants (POL)-contaminated soil and water on utility projects; it has been recently utilized for sites within PFAS plumes as well. Clean cover material is required to eliminate direct contact.

• The project team should also consider design concepts and changes from a worker health and safety standpoint to limit exposure to contamination by construction workers and others around the project site.

• Once the project site is approved, the project team must first test the soil to determine the presence of any hazardous substances, pollutants, or contaminants. After testing, the team should provide the installation ERP office with a written description detailing the contaminants (e.g., concentrations, cleanup site boundaries, proposed remedies, LUCs) considered in the site selection, along with evidence that these impacts are accounted for in the project design, cost, and schedule.

Project Execution Construction projects at or near DERP sites should be closely coordinated with the ERP office and in compliance with applicable State and Federal environmental regulations. For execution of projects planned and programmed prior to the development of this BMP guidance, engage with the ERP office to identify any site changes and to adopt the BMPs where needed. Develop a Soil Management Plan (SMP) or consult with the ERP office to determine if there is an installation SMP to outline storage, handling, and management of soils. At some sites it may be beneficial to conduct soil and groundwater sampling as part of a pre-design investigation to understand the nature and extent of contamination in the planned project footprint. This information will be useful to inform potential design changes to avoid or minimize excavation of contaminated soil. Additionally, projects in contaminated areas must consider health and safety measures to protect project workers and others nearby from exposure to contamination.

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Focused Environmental Investigation

A focused environmental investigation of soil and groundwater within the project footprint should be performed concurrently with the geotechnical investigation for project sites where there is no prior environmental investigation data available or where the available historic data was collected using outdated analytical methods. Such an investigation is not required in project areas where recent data has been collected using current approved analytical methods (e.g. USEPA method 1633 for PFAS) and the results of samples within the project footprint show contaminant concentrations to be below the applicable State, USEPA or DoD and/or DAF screening criteria (e.g. USEPA Regional Screening Levels [RSLs] for screening PFAS).

Prior to performing such an investigation, preparation of a work plan is recommended for regulatory review. The work plan should outline the sampling locations and approach; sample analysis and analytical methods; and screening criteria for each contaminant or contaminant class depending on project end-use (residential or industrial/commercial use) and exposure pathways (i.e., inhalation, ingestion, or dermal contact). Regulators in some states may agree to establishing site-specific risk-based soil and groundwater screening criteria that can benefit projects by allowing reuse of less impacted soils. Development of such site-specific criteria may require evaluation of natural background levels of the contaminants and the potential for contaminants to leach from the soil to groundwater. Establishing such alternative site-specific screening criteria should be considered by the project team in consultation with the ERP office. USEPA’s Soil Screening Guidance: User’s Guide provides additional information on sampling, analysis, and establishing screening levels. The following are recommended steps for performing a focused environmental investigation:

• Space out sampling locations adequately to ensure proper data density can be collected to inform boundaries for excavation and segregation. Generally, a spacing of 100 feet is standard practice in site investigations; but this spacing can be increased or decreased based on the size of the sampling area and data needs. Interstate Technology and Regulatory Council (ITRC) recommends the Incremental Sampling Methodology (ISM) approach.

• Sampling can be performed using a hand auger for shallow investigations (<10 feet) or using one of several drilling methods such as direct push technology (DPT) or hollow stem auger with split spoon samplers for deep investigations (>10 feet).

• Collect soil samples at discrete depth intervals from the surface to the lowest depth of the planned excavation. It is standard practice to collect samples every 2 to 3 feet, but sample depths can be adjusted depending on excavation depth and data needs to identify contaminated and uncontaminated intervals for soil segregation purposes.

• For groundwater characterization at each location, one sample should be collected at or just below the water table using low-flow sampling. This sampling method is the USEPA’s accepted standard practice for sampling groundwater. The details of USEPA acceptable methods for groundwater sampling at RCRA and CERCLA site can be found at https://www.epa.gov/remedytech/ground-water-sampling-guidelines-superfund-and-rcra-project-managers.

• If the contaminants are known from prior environmental investigations, soil and groundwater samples should only be analyzed for those site-specific contaminants. A full suite of analysis including VOCs (USEPA Methods 5035A and 8260C), SVOCs (USEPA Methods 3510C and 8270D), metals (USEPA Methods 6010 or 6020), total petroleum hydrocarbons – diesel range organics (TPH-DRO) (USEPA Methods SW-846 3510C and 8270D), total petroleum hydrocarbons – gasoline range organics (TPH-GRO) (USEPA Methods SW-846 3510C and 8270D), pesticides (USEPA Methods 3510C and 8081B), herbicides (USEPA Methods 3510C and 8151A), and PFAS (USEPA Method 1633) will be required for soil and groundwater samples where prior information on contaminants does not exist. All samples should be analyzed by a DoD Environmental Laboratory Accreditation Program (ELAP)-certified laboratory.

• Based on State-specific soil disposal regulations, soil samples may require additional analysis by the Toxicity Characteristic Leaching Procedure (TCLP) for the above analytes (excluding PFAS) and/or the Synthetic Precipitation Leaching Procedure (SPLP) to assess if the soils will be characterized as hazardous or non-hazardous waste for disposal purposes. Depending on site-specific contaminants, the analyses will include one or more from the following list:

o TCLP RCRA metals and mercury via USEPA Methods 1311, 3010A, 6010C/D, 6020C, and 7470A/7471A o TCLP VOCs via USEPA Methods 1311, 5030C, and 8260C o TCLP SVOC via USEPA Methods 1311, 3510C, and 7270D o TCLP pesticides via USEPA Methods 1311, 3510C, and 8081B https://semspub.epa.gov/work/HQ/175238.pdf https://ism-2.itrcweb.org/nature-of-soil-sampling/ https://www.epa.gov/remedytech/ground-water-sampling-guidelines-superfund-and-rcra-project-managers ϲ o TCLP herbicides via USEPA Methods 1311, 3510C, and 8151A o pH/corrosivity (USEPA Method 9040C/9045C) o Flash point (USEPA 1010A) o Reactivity (sulfide and cyanide; USEPA 335.4).

• Detailed requirements for TCLP analysis are available from the USEPA at https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure.

• All equipment that comes in contact with contaminated media must be properly decontaminated prior to mobilization outside project area boundaries. Decontamination and other investigation derived wastes are to be collected and stored in 55-gallon drums. The drums must be properly labeled and stored on pallets in an on-base waste accumulation area in a timeframe not to exceed the requirements of a RCRA Central Accumulation Point (usually 90 days for a Large Quantity Generator) and applicable laws until sampled, characterized, and disposed at an appropriate disposal facility based on TCLP analysis on composite soil samples listed above. A test of ignitability may also be required in accordance with methods outlined in United States Code of Federal Regulations (CFR) (40 CFR § 261.21).

If unexpected impacted environmental media are discovered at an ongoing MILCON or FSRM site, consult with the ERP office to assess if concentrations of contaminants are at levels governed by environmental standards or DoD and DAF policies. This guidance does not specify the concentration limits to be met, but instead requires the project team to work with the installation’s ERP office, and possibly the installation’s legal office to establish media specific management requirements.

A solid waste is designated as hazardous if it is listed as a hazardous waste or has one of the following characteristics of a hazardous waste: ignitable, corrosive, reactive, or toxic. Based on the results of the focused investigation, the soils may be classified into three categories:

1. Soils for reuse without disposal requirements – Contaminant concentrations are below laboratory detection levels. Such soils can be reused on-site with regulatory approval and excess can be disposed without restrictions.

2. Soils for reuse with disposal requirements – Contaminants are detected but concentrations are below the appropriate soil screening criteria. Such soils can be reused on-site with regulatory approval, but excess may need to be disposed of at non-hazardous waste disposal (RCRA Subtitle D Landfill) or municipal landfill depending on contaminants present.

3. Impacted Soils for treatment or hazardous waste disposal – One or more of the contaminants exceed the soil screening criteria. Such soil needs to be disposed in a RCRA Subtitle C landfill or will require pretreatment for reuse or disposal in a RCRA Subtitle D landfill.

Site Preparation and Construction

There are steps that the project team can take during the initial phases of project execution to avoid or minimize disturbance of contaminated media. Wherever possible, plan projects and stage materials and equipment in areas free from contamination.

Avoiding impacted areas is preferable to mitigation, provided that operational requirements do not necessitate placing the project in a contaminated location. For most projects, any added cost of changing project location and/or design to avoid contaminated areas will likely be offset by costs and schedule delays associated with managing contaminated media, especially if PFAS are present. Following are some recommendations:

Focused Environmental Investigation

• Soils sampling locations are generally 100 feet apart but spacing can be less or more based on investigation area size

• Discrete soil sampling at each location vertically every 2–3 feet from surface to the lowest depth of excavation, but interval size can be >2–3 feet depending on data needs

• Groundwater sampling at the water table, if encountered

• If no prior sampling data, analyze soil and groundwater samples for contaminants – VOCs, SVOCs, metal, pesticides, herbicides, TPH-DRO, TPH-GRO, and PFAS

• Investigation derived waste (IDW) (soil, groundwater) will be stored in drums for characterization and disposal or treatment

• TCLP analysis of soil and IDW to determine disposal options https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure ϳ

• Look for opportunities to implement remedial actions such as chemical stabilization or treatment rather than stockpiling and disposing of contaminated soils during site preparation. Regulatory concurrence may be required prior to implementation of remedial actions.

• Normally frozen ground should not be thawed during construction if nearby groundwater is contaminated. Frozen ground obstructs the flow of contaminated groundwater; working in permafrost or frozen wetland areas will minimize dewatering, as well as prevent contaminated groundwater from entering the site. Thawing allows the groundwater to flow and potentially spread contamination, as well as creating a contaminated dewatering issue. Shallow cutoff walls or ice walls should be considered to stop incoming contaminated water in sites with very shallow groundwater.

• During construction, do not allow water ponding in low lying areas as this could result in more contaminated water and raising the nearby water table, which will increase dewatering volumes.

• Ensure that the site-specific construction Storm Water Pollution Prevention Plan (SWPPP) delineates suspected areas of contamination, area(s) for stockpiling soil, and desired actions for managing the contaminated soil.

• Account for applicable stormwater permit requirements, which include implementation of pollution control measures such as controlling runoff from stockpiles. Installation Municipal Separate Storm Sewer System (MS4) or individual stormwater permits may require oversight of construction activities including activities covered under a construction stormwater permit.

• Depending on the contaminants present, especially PFAS, and their concentrations in soil and water, the construction area may need to be managed as a cleanup site. This would entail avoiding tracking contaminated soil onto roads;

covering soil loads being transported; covering soil stockpiles; restricting access; creating a decontamination area for equipment and workers; and instituting sediment runoff controls.

Soil Segregation and Handling

Excavation in a contaminated footprint should be approached surgically with equipment and methods that allow removal of soils from contaminated locations and depth intervals without mixing contaminated soils with uncontaminated soils. The following are some best practices on segregation and handling of contaminated soils:

• Decontaminate excavating equipment between locations and depth intervals to avoid cross-contamination. To the extent practicable, sequence field activities such that clean soils are excavated first followed by contaminated soils in increasing order of contamination. This sequencing will avoid the need to frequently decontaminate the equipment and will limit the risk of cross-contamination.

• Store Excavated soils from uncontaminated locations and depth intervals separately from soils from contaminated locations and depth intervals (i.e., create separate stockpiles of clean and contaminated soils). Saturated and unsaturated soils should be segregated if the contamination is only in groundwater.

• Where possible, stage the contaminated soil stockpile within the boundaries of the active work zone and away from civilian work areas. Construct the contaminated soil stockpile with a sufficiently strong and durable impermeable liner or plastic both underneath and on top in a covered enclosure. This cover will prevent contaminated soils from being blown by wind and runoff from rainwater infiltration. The placement of a liner will help to delineate where the impacted soil ends, and the regular ground surface begins, so that there is no risk of over-excavation when the soil is moved for disposal or treatment.

• Stockpiles can also be constructed in lined roll-off containers that are placed in secondary containment.

• If the contaminated soil is stockpiled in an enclosure, then it should have restricted access and adequate ventilation to prevent accumulation of contaminated soil vapor in the indoor air.

Contaminated Soil Stockpile Construction

• Impermeable liner underneath prior to pile construction over an impervious surface such as asphalt or concrete

• Enclosure or impermeable cover on top and around the pile to prevent runoff and wind erosion

• Erosion and runoff controls with straw berms or silt fencing surrounding the stockpile

• Institutional and engineering controls for health and safety to prevent contaminant exposure

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• For wet contaminated soils, the stockpile should be constructed with an underdrain and water collection system for dewatering purposes.

• Runoff and erosion control measures such as silt fencing or straw berms may be required.

• Regularly inspect and maintain soil stockpiles to ensure the cover remains intact, excessive water does not accumulate, wattles remain in place, signs are legible and in place, and safety warning devices are present and upright.

Soil Management and Treatment

While clean soil can be reused at the project site without further treatment, the contaminated soil will need to be managed either through landfill disposal or through treatment prior to disposal or reuse. Depending on the contaminants present in the soil stockpile and their concentrations, the stockpile will qualify for disposal either as hazardous or non-hazardous waste. Disposal of contaminated soils in landfills as hazardous or non-hazardous waste has been in practice for decades. However, disposal of PFAS-impacted soils is presenting a challenge because it is costly and many landfills are unwilling to accept PFAS wastes because of compliance issues and lack of adequate treatment technologies for PFAS in landfill leachate. If PFAS contamination is encountered, follow the DoD Interim Guidance and State-specific waste disposal regulations. The guidelines and recommendations in the DoD Interim Guidance are generally consistent with USEPA’s Interim Guidance.

Soil Disposal or Reuse

Generation and disposal of solid waste is generally governed by the Solid Waste Disposal Act, then amended as RCRA. The DAF follows requirements in the DERP manual (Section 6b) for transfer of wastes to off-site facilities. In addition to other contaminants, in February 2024, the USEPA proposed listing nine PFAS as RCRA hazardous constituents. These nine PFAS are perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorobutanesulfonic acid (PFBS), hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), perfluorodecanoic acid (PFDA), perfluorohexanoic acid (PFHxA), and perfluorobutanoic acid (PFBA). Once the listing of PFAS as hazardous substances under RCRA is finalized, this listing will govern the duration of time (expected to be 90 days) the PFAS-contaminated soils are permitted to remain stockpiled on site.

The stockpiled soil will require sampling to confirm the initial classification from the focused environmental investigation.

Composite samples from the stockpile should be analyzed for site-specific contaminants or the same constituents as those analyzed during the focused investigation although additional parameters may be required by the specific disposal facility.

Number of samples depends on the size of the stockpile. Table 1 provides recommended guidance based on recent stockpile sampling performed at Ellsworth Air Force Base.

Table 1 Recommended number of samples based on stockpile size

Stockpile Size (cubic yards) Number of Stockpile Samples

0 to 100 2

101 to 1,000 3

1,001 to 50,000 5

50,001 to 100,000 10

>100,000 10 + 1 for each additional 50,000 cubic yards

Following is recommended guidance on contaminated soil disposal or reuse:

• Compliance with applicable Federal, State, and local requirements is required for any task involving the transportation and disposal of solid or hazardous wastes. These include 40 CFR 260-265 and 268, and 49 CFR 171, 172, 173, 178, 179 and other applicable regulations.

Perform a cost-benefit analysis between disposal and treatment options to decide on the most cost-effective means of managing contaminated soils.

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• For soils contaminated with PFAS, DoD guidance recommends disposal at RCRA Subtitle C Landfills with environmental permits. There are currently 33 such landfills located across the lower 48 states. These landfills can be found using the USEPA Incident Waste Decision Support Tool (I-Waste DST) website (https://iwaste.epa.gov/treatment-disposal-facilities). If disposal at a RCRA Subtitle C Landfill is not feasible because such a landfill does not exist within a reasonable distance from the project site, the next disposal option is a Solid Waste Landfill with an environmental permit that has a composite liner along with leachate and gas collection and treatment systems.

• Consider the cost-benefit of treating contaminated soils with amendments or binders prior to disposal as this treatment can stabilize contaminants and reduce leachability thereby allowing for disposal as non-hazardous waste.

• With regulatory approval, impacted soil and groundwater can be placed back at the construction site in the location from which it was removed but the location of the reused soil must be documented for possible future investigations.

• Documentation of any sampling and testing results, and reuse or disposal actions should be prepared in a summary report in accordance with Unified Facilities Guidance Specification (UFGS) Section 01 57 19 – Temporary Environmental Controls, Section 02 61 13 – Excavation and Handling of Contaminated Material, and Section 02 81 00 – Transportation and Disposal of Hazardous Materials.

Soil Treatment

Depending on the soil volume and contaminants present, it may be cost-effective for some sites to treat the contaminated soil (and groundwater if needed) in place prior to project start or in stockpiles upon removal for reuse or disposal as non-hazardous waste. Soil treatment technologies for legacy contaminants (e.g., VOCs, SVOCs, metals) are well established and a compilation of these technologies is available from Federal Remediation Technologies Roundtable (https://www.frtr.gov/matrix/). Additionally, USEPA developed BMPs for soil treatment technologies (https://www.epa.gov/hw/best-management-practices-bmps-soils-treatment-technologies). For PFAS contaminated soils, however, treatment technologies are still being developed and tested.

These technologies are summarized in Sections 12.3 and 12.7 of ITRC’s PFAS guidance document (https://pfas- 1.itrcweb.org/12-treatment-technologies/). Following are some recommendations for considering soil treatment:

• Review the above referenced technical resources for detailed information and consult with the ERP office to identify technology(ies) suitable for site-specific contaminants and conditions.

• Prior to selecting a treatment technology to address contaminated soils in place or in stockpiles, small-scale bench and/or pilot tests may be required to screen technologies and assess their performance for site-specific soils before full-scale treatment.

• Technologies may be limited by the volume of soil they can treat at one time. Depending on the technology, large stockpiles may need to be treated in small batches to maximize treatment efficiency.

• Along with bench- or pilot-scale testing, perform a cost-benefit and sustainability analysis for the screened technologies when selecting a treatment option for the site.

Dewatering and Water Treatment

Dewatering via pumping groundwater or pooled rainwater from the excavation area may be required at some project sites.

Additionally, dewatering may also be necessary for wet soil stockpiles. The focused environmental investigation in the excavation area will provide information on the potential for the extracted water to be contaminated. Water removed during construction excavation activities that will be discharged to surface water or injected underground must comply with the Clean Water Act (CWA) or underground injection requirements including dewatering permits and construction stormwater permits. In addition, the control of contaminants due to construction activities may be subject to base environmental compliance oversight as a minimum control measure (MCM) of the Installation MS4 permit. The project team should coordinate with the ERP office to ensure discharges from the project do not contain hazardous substances, pollutants, or contaminants above regulatory or applicable permit limits. The following is recommended guidance on dewatering and management of contaminated water:

• Account for permitting requirements in the project plan. Some State or Federal regulatory agencies with CWA primacy issue dewatering permits which may include requirements to control the spread of pollutants.

• Communicate with the ERP office to obtain a better understanding of previously tested technologies at the site.

https://iwaste.epa.gov/treatment-disposal-facilities https://iwaste.epa.gov/treatment-disposal-facilities https://www.frtr.gov/matrix/ https://www.epa.gov/hw/best-management-practices-bmps-soils-treatment-technologies https://www.epa.gov/hw/best-management-practices-bmps-soils-treatment-technologies https://pfas-1.itrcweb.org/12-treatment-technologies/

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• Temporary storage of extracted groundwater in holding tanks may be required prior to treatment

• While a temporary treatment system can be constructed at the project site, it may be possible at some installations to transfer the extracted groundwater to a centralized water treatment plant, only if it is capable of handling PFAS-impacted water.

• The treatment system will likely require removal of suspended solids as an initial step followed by treatment with one or more technologies depending on the contaminants present and the level of impacts.

• If the water is impacted with PFAS, granular activated carbon (GAC) alone will not be sufficient to treat it as GAC is known to be ineffective in removing short-chain PFAS. In addition to GAC, the treatment train will likely include PFAS-tailored sorbent, ion-exchange resin (IER), or foam fractionation depending on concentrations of PFAS, flow rates, and water quality.

• Prior to implementation of water treatment, small-scale bench testing is recommended to screen treatment technologies, assess performance, and inform treatment system design for site-specific conditions. Such tests may not be needed for sites where centralized treatment plants are present and technologies have been vetted previously.

The DoD currently prohibits incineration of materials containing PFAS. Treatment media, such as the used granular activated carbon (GAC) or ion exchange resin, can be disposed of at a municipal solid waste facility or be sent to a treatment media regeneration facility.

Health and Safety Considerations

Project work on a contaminated site must conform to 29 CFR § 1910.120, Occupational Safety and Health Administration (OSHA) requirements for workers’ health and safety as there are likely to be dermal and inhalation exposure risks from impacted soil and groundwater. Additionally, measures are needed to control dust and prevent airborne spread of contaminated soils to surrounding areas. An advantage of changing project location or making design changes to avoid a contaminated area is eliminating the need (and therefore the cost) to provide extensive health and safety controls. Often, more time is required for performing activities when using additional health and safety precautions thereby extending the project schedule. The following is recommended guidance for addressing health and safety concerns associated with management of contaminated soil and groundwater from excavation:

• Depending on the contaminants present and their levels in soil and groundwater, consider provisions for special personal protective equipment (PPE) beyond Level D, which is typically required for construction workers.

• Ensure that construction workers and site personnel have appropriate level of health and safety trainings such as the Hazardous Waste Operations and Emergency Response (HAZWOPER) and the Site Supervisor HAZWOPER.

• Dust monitoring and other contaminant-specific monitoring equipment are required to monitor levels in the active work areas during excavation, handling, and stockpiling of contaminated soils.

• Contaminated soils transported for disposal must be covered and decontamination measures may be needed for equipment and workers to ensure that contamination does not spread to uncontaminated areas.

References and Resources

• Policies and Regulations o AFI 32-1015, Integrated Installation Planning, Corrective Action, January 4, 2021 o Assistant Secretary of Defense Memorandum “Interim Guidance on Destruction or Disposal of Materials Containing Per- and Polyfluoroalkyl Substances in the United States” July 11, 2023 o Assistant Secretary of Defense Memorandum “Guidance on Incineration of Materials Containing Per- and Polyfluoroalkyl Substances” July 14, 2023

Dewatering and Liquid Management

• Need for temporary holding tank and water treatment prior to discharge

• Use of temporary onsite treatment system or on-base centralized water or effluent treatment plant

• Solids removal will likely be required prior to water treatment

• Bench-scale testing recommended to help with treatment media and technology selection and design for any temporary onsite treatment system o Assistant Secretary of Defense Memorandum “(stablishing a Consistent Methodology for the Analysis of Per-and Polyfluoroalkyl Substances in Matrices 2ther than Drinking :ater” May 1, 202� o Assistant Secretary of Defense Memorandum “InYestigating Per- and Polyfluoroalkyl Substances Zithin the Department of Defense Cleanup Program” January 21, 202� o �2 U�S�C� ����01-����, C(5C/A � ComprehensiYe (nYironmental 5esponse, Compensation, and /iability Act �Superfund� o DA)I 32-1020, Planning and Programming %uilt Infrastructure ProMects �July 20, 2023� o DAFI 32-7020, Environmental Restoration Program, May 16, 2024 o DAFM 32-1067, Water and Fuel Systems, August 13, 2024.

o DAFM 32-7002, Environmental Compliance and Pollution Prevention, February 4, 2020 o Department of Defense Memorandum “Interim Guidance on Destruction or Disposal of Materials Containing Per- and Polyfluoroalkyl Substances in the United States” July 11, 2023 o DoDM 4715.20, Defense Environmental Restoration Program (DERP) Management, August 31, 2018 o National Defense Authorization Act (NDAA) o Resource Conservation and Recovery Act (RCRA) o UFC 3-460-01 Chapter 14 o UFC 2-100-01 Appendix D o UFGS 01 57 19 – Temporary Environmental Controls o UFGS 02 61 13 – Excavation and Handling of Contaminated Material o UFGS 02 81 00 – Transportation and Disposal of Hazardous Materials o 10 USC, Chapter 169 o 10 USC, 2701 o 42 USC, 6901- 6992 o USEPA, “Interim Guidance on Destruction and Disposal of Perfluoroalkyl and Polyfluoroalkyl Substances and Materials Containing Perfluoroalkyl and Polyfluoroalkyl Substances - Version 2”, April 8, 2024 o 10 CFR, 261.21 o 29 CFR, 1910.120 o 40 CFR, 260-265 and 268 o 49 CFR, 171-173 and 178-179

• Forms o Enclosure 1 - Air Force Form 813 (AF Form 813) o Enclosure 2 – Example Environmental Scoping Checklist

• Websites o https://ar.cce.af.mil/ o https://www.epa.gov/remedytech/ground-water-sampling-guidelines-superfund-and-rcra-project-managers o https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure o https://iwaste.epa.gov/treatment-disposal-facilities o https://www.frtr.gov/matrix/ o https://www.epa.gov/hw/best-management-practices-bmps-soils-treatment-technologies o https://pfas-1.itrcweb.org/12-treatment-technologies/ o https://semspub.epa.gov/work/HQ/175238.pdf

Version: 02/12/2025 https://www.epa.gov/remedytech/ground-water-sampling-guidelines-superfund-and-rcra-project-managers https://www.epa.gov/hw-sw846/sw-846-test-method-1311-toxicity-characteristic-leaching-procedure https://iwaste.epa.gov/treatment-disposal-facilities https://www.frtr.gov/matrix/ https://www.epa.gov/hw/best-management-practices-bmps-soils-treatment-technologies

Enclosure 1

Enclosure 1 – AF Form 813

Enclosure 2

Enclosure 2 – Environmental Scoping Checklist

Environmental Scoping Checklist Environmental Scoping Questions Status Notes

Is there impacted soil on the site of the Proposed Action/Activity (PA/A)? Check with the base installation restoration team (IRT).

□No □Unknown □Yes

Will the PA/A involve excavating impacted soil for which establishing holding areas or soil stockpile(s) may be needed?

□No □Unknown □Yes

Is there a water source nearby that may be impacted by construction activities that may spread or migrate contamination?

Example: Dewatering in or near groundwater contamination.

□No □Unknown □Yes

4 Will the disturbance of impacted media affect any drinking water sources?

□No □Unknown □Yes

Will there be any restrictions on discharges or wastes because of the presence of contamination?

□No □Unknown □Yes

Is there suspected contaminant presence on any surfaces or media that may incur additional testing or disposal costs?

Example: PFAS impacted asphalt or concrete associated with:

• Fire Training Areas

• Hangar fire suppression system use/test

• AFFF storage areas

• Aircraft firefighting activities

• Electrical/chemical firefighting activities

□No □Unknown □Yes

Comments

□ No Further Action Required □ See the Attached Analysis

Date (mm/dd/yyyy) Office Symbol Signature

This checklist is not intended to introduce or require any particular action or additional cost to the process. This checklist should be used at the planning stage for every facility project, where the risk of encountering hazardous substances, pollutants, or contaminants should be assessed and planned for. Prior to engaging in additional testing, stockpiling, or prior to making commitments to local regulators, consult with the ERP office and seek legal advice from AF/JAOE-FSC and Air Force Emerging Contaminants team (AFCEC/CZR) or SMEs in AFCEC/CZTE and

AFCEC/CZTQ

Acronyms and Abbreviations

Acronyms and Abbreviations

AF Form 813 Air Force Form 813 AFI Air Force Instruction

AFCEC Air Force Civil Engineer Center

ANG Air National Guard BMP best management practice BRAC Base Realignment and Closure CATEX Categorical Exclusion CDD construction and demolition debris CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal…