Kenilworth Park Landfill Site

Kenilworth Park Landfill Site is located within Anacostia Park, a unit of National Capital Parks – East, on the eastern bank of the Anacostia River. The Site is divided into two areas, Kenilworth Park North (KPN) and Kenilworth Park South (KPS). The areas are separated by Watts Branch, a stream that flows into the Anacostia River.

 

 

Site Map

Site History

From 1942 until 1970, the District of Columbia (District) operated a landfill in the area that became Kenilworth Park. The landfill received municipal waste and ash from several District municipal waste incinerators. Landfill activities started in the northern area (Kenilworth Park North, or KPN) between Watts Branch and Kenilworth Aquatic Gardens and eventually spread into the area south of Watts Branch (Kenilworth Park South, or KPS) in the late 1950s.

Waste disposed in the landfill included solid municipal waste and ash from District municipal solid waste incinerators. The municipal waste was burned openly and buried from 1968 to 1970. In 1970, open burning of waste ended but waste continued to be brought onsite and buried. In 1970, landfill operations ceased in both areas (KPN and KPS), and the entire landfill was covered with soil, revegetated, and reclaimed for recreational purposes. Athletic fields currently occupy KPN; KPS is undeveloped.

 

Drilling and logging at Kenilworth Park South

Kenilworth Park Landfill Environmental Investigations

In October 1998, NPS started cleanup activities at the Kenilworth Park Landfill Site under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA provides a framework for the Federal government to assess and respond to hazardous substances that have been released or have the potential to be released into the environment. At the KPL Site, NPS is the Federal government agency in charge of the CERCLA response action (known as the “lead agency”). CERCLA’s associated regulations are provided in the National Oil and Hazardous Substances Pollution Contingency Plan or NCP. The NCP describes the specific steps that are undertaken during a CERCLA response action.

1998 - 2002 – Preliminary Assessment/Site Inspections

The first step undertaken for a CERCLA response action is the Preliminary Assessment (or “PA”), followed by the Site Inspection (or “SI”). The purpose of these two steps is to determine if the Site warrants additional assessment under CERCLA. To make this determination, NPS reviewed historical information and collected environmental samples from the Site. Based on the results of the PA/SI, NPS determined that additional investigation and assessment under CERCLA were needed.

2007 - 2008 – Remedial Investigations

The next step in the CERCLA process is the Remedial Investigation (or “RI”). The purpose of a RI is to determine the nature and extent of contamination at a site and assess potential threats to human health and the environment. In 2007, NPS completed an RI for the KPN area of the Site; NPS completed the RI for KPS area in 2008.

The RI phase identified polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), dieldrin (a pesticide), arsenic, and lead in surface or subsurface soil as contaminants of potential concern for human health. The data collected during the RI phase did not indicate the Site was a significant source of contamination to adjacent surface water bodies (Anacostia River, Watts Branch, and Kenilworth Marsh) via either “overland flow” (i.e. rainfall runoff across the surface of the former landfill) or groundwater discharge to surface water. Although existing data did not identify exposure risks associated with groundwater underlying the Site, NPS determined that additional assessment of shallow groundwater was warranted to fill data gaps and confirm groundwater that discharges into surface water is not posing a threat to surface water or sediment quality or the local ecology.

Often during cleanup activities, complex sites may be divided into several distinct areas. These areas, called operable units (OUs), may address geographic areas, specific problems, or environmental media (for example, groundwater or soil) where a specific action is required. Following the completion of the initial phases of the RI, NPS separated the Site into two OUs. OU1 consists of surface and subsurface soils and waste that was disposed in the landfill.

OU2 consists of shallow groundwater beneath OU1.

2012 – Feasibility Study – OU1

The Feasibility Study (or “FS”) stage of the CERCLA process follows the RI. The purpose of the FS is to identify and evaluate possible alternatives to address contamination at the Site that was determined by the assessments completed as part of the RI to pose unacceptable risk to human health or the environment. The FS completed in 2012 only addressed OU1 (surface and subsurface soils and waste) and includes the evaluation of potential alternatives and cost estimates for addressing OU1. In 2012, NPS prepared an FS for OU1 that evaluated cleanup alternatives to address contamination found in surface and subsurface soil and buried waste. The chosen alternative was documented in the Proposed Plan, released in 2013.

2013 – Proposed Plan

The FS for OU1 was followed by development of the Proposed Plan to address OU1. NPS released the Proposed Plan for public comment in February 2013 and presented it at a public meeting in April 2013. The plan identified the preferred cleanup alternative as the installation of a 24-inch-thick soil cap over most of the landfill area within KPN and KPS. After considering the public comments to the Proposed Plan, NPS decided that the selection of a cleanup plan for OU1 could be influenced by additional investigations scheduled for OU2 (groundwater). Therefore, NPS deferred selection of a cleanup alternative for OU1 until additional investigations were completed for OU2.

2013 – 2019 - RI Addendum Activities

Between 2013 and 2019, NPS completed multiple phases of additional RI activities. The purpose of these activities was to further assess OU2 (shallow groundwater) to determine the quality of the groundwater below and migrating from the Site. In addition, since releasing the Proposed Plan for OU1, NPS developed an updated vision for future use of KPS. Rather than redevelopment for recreation, as was the vision during the original RI, NPS determined that KPS would be managed as a “Natural Resources Recreation” area for passive recreational use, including the planned extension of the Anacostia Riverwalk Trail (a paved walking and cycling trail that currently passes over the northern area of KPN) and birdwatching activities. NPS’s revised plan for KPS is described in the 2017 Anacostia Park General Management Plan. Because NPS revised the management plan for KPS, it was necessary to reevaluate visitor soil exposure risk. This reevaluation is detailed in the 2019 RI Addendum Report.


In addition to the reassessment of risk to visitors of KPS, the 2019 RI Addendum Report summarizes the findings of the field activities completed from 2013 to 2018 that were focused on the assessment of OU2 (shallow groundwater). Based on the results of human health and ecological risk assessments documented in the 2019 RI Addendum Report, NPS determined the following:

• Groundwater associated with the Site does not pose an unacceptable risk to human health or the environment.
• Contaminants found in surface soil used to cover the landfill after closure pose a potentially unacceptable human health risk under certain high-intensity and high-frequency visitor exposure scenarios (e.g., playing contact sports on the athletic fields).
• Lead in subsurface soil and buried waste, and the potential presence of unexploded ordnances and methane gas pose a potentially unacceptable human health risk to excavation workers.
• Contaminants found in soil or buried waste do not pose an unacceptable risk to ecological receptors.

2020 - Feasibility Study Addendum Report

The purpose of the FS Addendum was to identify and evaluate possible cleanup alternatives that would address the unacceptable risk identified by the RI Addendum (see bullets above). To address this risk, NPS developed and evaluated five cleanup alternatives. Details of the five alternatives and the associated evaluations are presented in the Feasibility Study Addendum Report which NPS completed in September 2020.

November 2020 Proposed Cleanup Plan

Based on the evaluation summarized in the September 2020 Feasibility Study Addendum Report, NPS chose Alternative 3 (placement of clean soil fill in the planned high frequency and high intensity use areas such as athletic fields and implementation of protective institutional/administrative controls such as extra safety precautions before digging) as the preferred cleanup alternative for the Site. On November 12, 2020, NPS released the Proposed Cleanup Plan for the Kenilworth Park Landfill Site to explain the preferred alternative and invite public comment on the plan. NPS chose Alternative 3 because it will achieve substantial risk reduction while focusing on areas of the Site with greatest potential exposure risks. This alternative will allow the Site to be used as intended for both active and passive recreational activities, while reducing risk sooner and at a lower cost than the other alternatives. NPS recorded a video presentation that explains how NPS chose the preferred alternative and describes the Proposed Cleanup Plan for the Site.

 

Duration:

25 minutes, 50 seconds

The Kenilworth Landfill is an environmental hazard that the National Park Service is cleaning up. This video explains how the National Park Service chose the preferred alternative and gives a description of the proposed cleanup plan for the site.

 

Record of Decision

NPS released the Record of Decision (ROD) for the KPL Site on December 20, 2022. The ROD describes the Selected Remedy (final cleanup plan), NPS chose in consultation with the District’s Department of Energy and Environment (DOEE), acting as the support agency, and after reviewing and considering comments and input submitted during the public comment period. The Selected Remedy is a modified version of the Alternative 3 that was described in the Proposed Plan released in November 2020 and includes placement of a one-foot-thick, clean soil layer on areas of KPN where the District intends to redevelop for high-intensity, high-frequency recreational uses including, but not limited to athletic fields for organized sports. NPS modified Alternative 3 by reducing the area to be covered by a clean soil layer because the District informed NPS that portions of KPN will be reserved as natural resource areas such as tidal wetlands and meadows. Any areas of KPN that will not be developed for active recreational uses will not be covered with the clean soil barrier.

Next Steps

The remedial design phase is the next step of the CERCLA response action to be completed. In this phase, more detailed plans and construction specifications will be prepared. This phase will also include completion of a pre-design investigation that will provide data that will be used to inform the final construction plans. The final boundaries for the clean soil barrier to be placed at KPN will be detailed on the construction plans and will be based on the District’s final land use plans for KPN. The District has notified NPS that it will host public meetings in 2023 to accept public input on the District’s redevelopment plans for KPN. It is estimated that this phase will take approximately one year to complete, but that timeline may change based on developments in the field or other factors.

The implementation phase of the CERCLA response action will follow the remedial design phase. During this phase the construction or implementation of the Selected Remedy described in the ROD and specified in the remedial design documents will be completed (i.e., placement of the clean soil barrier, and other related site work and activities). It is estimated that this phase will take one year to complete.

Although the specific future roles and responsibilities of District government and NPS will be outlined in a future agreement, NPS will continue to oversee the CERCLA remedial action as the federal lead response agency. At this time, NPS anticipates the District will be responsible for completing the remedial design and implementation activities under NPS oversight.

NPS is interested in public feedback and works to maintain transparency in the CERCLA process. If you are interested in receiving email updates on the project, please email your request to Donna Davies.

 

Kenilworth Municipal Dump - May 24, 1967

Kenilworth Park Landfill Site Documents

The Site Administrative Record consists of the documents that form the basis for the selection of the remedy. The recently completed key documents are listed below and are available for download. The administrative record index lists all documents currently included in the Site's Administrative Record.

• Administrative Record Index

Community updates:

• 2020 Kenilworth Park Landfill Community Update (March)
• 2020 Kenilworth Park Landfill Community Update (November)
• 2022 Kenilworth Park Landfill Community Update (December)

Key site reports:

• 2019 Kenilworth Park Landfill Remedial Investigation Addendum Report
• 2020 Kenilworth Park Landfill Final Feasibility Study Addendum Report
• 2020 Proposed Plan for Cleanup of the Kenilworth Park Landfill Site (November)
• 2022 Record of Decision Kenilworth Park Landfill Site

The entire administrative record is available on compact diskettes at Benning (Dorothy I. Height) Neighborhood Library. Electronic copies of the administrative record documents are available to view on computers at the library. Electronic copies of the administrative record may also be requested by contacting the NPS Kenilworth Park Landfill Site CERCLA project manager, Donna Davies, at [e-mail] or [phone].

Benning (Dorothy I. Height) Neighborhood Library
3935 Benning Road NE
Washington, DC 20019
Phone: [phone]

 

Want to know more?

• Site History
• What is CERCLA?
• What is an Environmental Investigation?
• What is Risk Assessment?
• Conceptual Site Model
• Evaluation Criteria for Cleanup Alternatives
• Alternative 3
• Alternative 4
• Alternative 5

 

Contact Information

Donna Davies
CERCLA Project Manager
Address: National Capital Parks-East
1900 Anacostia Drive, SE
Washington, D.C. 20020
Email Donna Davies
Phone: [phone]
Mon.-Fri. 9:00a.m. - 4:00p.m. ET

 

Return to

• Anacostia Park Environmental Cleanup Projects
• Poplar Point Site
• Washington Gas Site