Washington Gas – East Station Site

Washington Gas - East Station Site is located in southeast Washington, D.C. along the western bank of the Anacostia River, south of “M” Street and east of 11th Street. The site includes areas impacted by the residuals of gas manufacturing.

 

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Site History

The Washington Gas - East Station Site (the Site) includes soil, sediment, and groundwater contaminated with hazardous substances from a former manufactured gas plant that once operated on an adjacent parcel of property to the north. The National Park Service (NPS), with support from the District of Columbia Department of Energy and Environment (DOEE), is currently overseeing investigations at the Site pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
The Washington Gas Light Company (Washington Gas) manufactured gas at its former plant continuously from 1888 to 1948 and intermittently until the mid-1980s. Coal and oil were the main gas-manufacturing materials. By-products of the manufacturing operations, including residual products from the cleaning of coke filter beds, tar that was mixed with solid waste, and wood chips contaminated with absorbed tar and cyanides were occasionally placed as fill on the Site. The plant was demolished in 1986, and the above-ground oil storage tanks were removed in 1997. The plant operations and disposal of materials generated during the manufactured gas production caused contamination of soil, groundwater, and river sediments.

The initial investigation and cleanup activities focused on the area bounded by Water Street, the southbound lanes of the 11th Street bridge, the Anacostia River, and the wooded area near the Eastern Power Boat Club. Subsequent investigations included sediments of the adjacent Anacostia River. The land portion of the Site was once owned by the federal government, but most of it is now owned by the District of Columbia (the District); the sediments of the Anacostia River are owned by the federal government. To allow some cleanup to occur while other investigation continued, the Site was divided into two Operable Units (OUs). OU1 is surface soils and subsurface soils (also known as the “landside portion”), and OU2 includes groundwater, surface water, and sediments of the Anacostia River (also known as the “in-river portion”). OU1 has a known physical boundary. The boundaries of OU2 are currently being determined through ongoing investigations.

 
Investigations at the Washington Gas Site
Contaminated surface soil removal at Washington Gas-East Station Site.

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Washington Gas-East Station Site Environmental Investigations

Beginning in 1983, a number of environmental investigations were conducted at and near the Site to evaluate the nature and extent of contamination, evaluate risks to human health and the environment, and analyze cleanup alternatives. Those investigations showed that the Site was contaminated with industrial waste from the former manufactured gas plant. Additionally, water beneath the surface at the Site, both shallow and deep, has also been determined to be contaminated with hazardous substances associated with those historical operations. Hazardous substances from the former plant have also been detected in the sediments of the Anacostia River.

Based on the results of these investigations, and in accordance with CERCLA, NPS selected a remedial action for OU1 in a Record of Decision (ROD) issued on September 14, 2006. The selected remedial action included:
(1) removal of the top 1 foot of contaminated surface soils and replacement with clean fill on the Government Property; and
(2) removal and replacement of certain contaminated subsurface soils up to a total depth of 3 feet below ground surface in that same area;
The OU1 ROD also recommended that an existing pump-and-treat system on the site of the former manufactured gas plant remain in operation and its effectiveness be further evaluated, and it also contemplated further investigation of OU2. In 2015, Washington Gas, with oversight from NPS and DOEE, performed soil removal at the Site and replaced excavated contaminated soils with clean fill and topsoil. NPS and DOEE assisted with selecting native meadow plants for OU1 that would increase biodiversity. Portions of the Site are currently fenced and signs are posted to control access while the vegetation becomes established. It is anticipated that the performance objectives of the OU1 Remedial Action will be achieved soon, but Site access may continue to be limited as OU2 work continues.

Washington Gas continues to operate a groundwater treatment system on the site of the former manufactured gas plant, capturing contaminants that may otherwise migrate off-site in groundwater.

Washington Gas began its investigation of OU2 in 2015. This investigation was intended to check the effectiveness of the groundwater treatment system and to determine the nature and extent of contamination in groundwater, surface water, and sediments of the Anacostia River resulting from historical operations at the former manufactured gas facility. At each important decision point during the investigation, Washington Gas summarized data collected in a Technical Memorandum, which also proposed the next investigation steps for NPS and DOEE to approve. One part of the investigation was performed on the upland portion of the Site (also identified as “landside”) and another part of the investigation was performed in the Anacostia River (also known as “in-river).

Summarized below is the OU2 work that Washington Gas completed between 2015 and 2019.

October 2015 through March 2016

Landside Investigative Activities:

Contractors for Washington Gas drilled test borings as deep as 80 feet below ground surface at 28 locations. Soil cores collected from these test wells were inspected for soil type and evidence of contamination, and samples were analyzed for manufactured gas-related chemicals. Field work finished in December 2015. Washington Gas prepared Technical Memorandum 1, which included cross-sections showing the geological layers along and away from the Anacostia River. The cross-sections show the geology, which may identify possible pathways for contaminants to travel through groundwater to the river. As part of Technical Memorandum 1, Washington Gas proposed locations and depths where groundwater samples should be collected to confirm if these pathways are present. During this subsequent field work, Washington Gas also collected samples of site-related contamination (coal tar) that collects in their recovery wells; this information can be used to compare chemical “fingerprints” in other samples.

April 2016 through May 2016

Landside Investigative Activities:

Contractors for Washington Gas drilled test wells at 24 locations and collected a total of 51 groundwater samples from various depths. The information from these groundwater samples indicated roughly how much water was flowing through the soil at each depth, and whether manufactured gas-related contaminants were present. The cross-sections were then updated with this information. Details regarding this work are documented in Technical Memorandum 2, which also presented proposed locations for groundwater monitoring wells. The purpose of the monitoring wells is to allow the collection of groundwater samples from the same locations at different times to provide information about how contaminants move in groundwater and how the contamination concentrations change over time.

June 2016 through March 2017

Landside Investigative Activities:

Washington Gas evaluated the data from their landside investigations, including geology, presence of contamination, groundwater movement, and groundwater sampling results, to identify areas where contaminants may be moving from the land towards or into the Anacostia River. Technical Memorandum 3 summarized this information and presented a proposal for collecting samples of sediment, surface water, and groundwater beneath the river in areas that were the most likely to be affected. Because the Anacostia River is tidal and contaminants can move both upriver and downriver, Washington Gas also identified locations in the Anacostia River that could serve as reference (i.e. background) locations to show the river’s conditions in areas not influenced by the Site.

April 2017 through October 2017

Landside Investigative Activities:

After reviewing the data from the landside investigation, the investigation area was expanded to the east to include the Eastern Power Boat Club. The Eastern Power Boat Club is being investigated separately under DOEE oversight. Contractors for Washington Gas drilled additional soil borings and installed groundwater monitoring wells to check for manufactured gas-related chemicals. The results of the investigation are presented in Technical Memorandum 5.

In-River Investigative Activities:

Washington Gas collected samples from the top 6-inch layer of sediment in the Anacostia River. Washington Gas used data reported from the analysis of these samples to propose 15 locations where samples would be collected to evaluate the aquatic biota living in the shallow sediment and the impact of the contamination detected to organisms living in the shallow sediments. The proposed sampling locations and rationale are described in Technical Memorandum 4.

In August 2017, Washington Gas expanded the in-river sampling area and collected additional sediment, surface water, and groundwater (beneath the Anacostia River) samples. Sediment cores were collected at a total of 72 locations from an area between the I-695 bridges downriver in the west, upstream to the eastern edge of the Eastern Power Boat Club property in the east. Results from this investigation will be reported and evaluated in the Remedial Investigation Report.

November 2017 through August 2019

Landside Investigative Activities (OU1):

Washington Gas combined all landside investigation data and used the concentrations in groundwater and the groundwater flow information to estimate the mass of contaminants that flow from the land across and beneath the seawall towards the Anacostia River. Some of these contaminants may discharge directly into surface water, while others flow into deeper soils beneath the river. Washington Gas determined that some of the manufactured gas-related contaminants discharged through or beneath the seawall. The results of this evaluation are summarized in Technical Memorandum 5.

In-river Investigative Activities (OU2):

Washington Gas provided NPS and DOEE results of the in-river sampling. NPS and DOEE agreed that the field work necessary to complete the Remedial Investigation Report was complete.

October 2019 through Ongoing

Landside Investigative Activities (OU1):

Washington Gas prepared and submitted to NPS a vegetation monitoring report for the 2018 season which documents the evaluation of the vegetation performance standards as required by the Consent Decree. NPS will review this report and determine if the vegetation performance standard has been achieved.

In-River Investigative Activities (OU2):

Washington Gas is currently preparing a Remedial Investigation Report for OU2. It is anticipated that the draft report will be submitted to NPS for review in spring 2020.

 

Community Involvement

Community involvement is an important part of the CERCLA process and the public will have the opportunity to review and comment on proposed cleanup actions. NPS will prepare Community Updates to communicate the current status of the work being completed at the Site. The most recent Community Update was prepared in March 2020.


 

Washington Gas - East Station Site Documents

The National Park Service maintains a record of all site related environmental investigations, ecological and human health risk assessments, community relations materials, public comments, and NPS responses to significant comments. Get site documents.

 

Contact Information

Donna Davies
CERCLA Project Manager

Address: National Capital Parks-East
1900 Anacostia Drive, SE
Washington, D.C. 20020
Email: e-mail us
Phone: (202) 359-3234
Mon.-Fri. 9:00a.m. - 4:00p.m. ET
 

Last updated: April 21, 2020

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