MISSION CLEANUP: Removal Action, Environmental Restoration Site 21
Former Sludge Drying Beds
The Naval Air Station (NAS) Patuxent River’s Environmental Restoration Program
The Naval Air Station (NAS) Patuxent River’s Environmental Restoration Program (ERP) is a partnership between the base, Naval Facilities Engineering Command (NAVFAC), the United States Environmental Protection Agency (USEPA), and the Maryland Department of the Environment (MDE). The mission of the ERP is to clean up federal land that was impacted due to past Navy activities, protect communities from possible contaminants associated with those activities, and restore the environment such that it productively re-used, while being mindful of taxpayer resources. That mission is executed by the Navy, with all decisions informed by sound science and agreements among members of a Tier I Partnering Team, composed of representatives of all four agencies. Final cleanup decisions are also informed by input from the public.
Environmental Restoration Program Site 21, Former Sludge Dying Beds
Site 21 was associated with the NAS’s former wastewater treatment plant (WWTP) located in the southcentral portion of the station. Though originally it was believed that the likely source of contamination was the sludge that the WWTP produced, environmental investigations did not identify any negative impacts. The investigations did, however, identify two other areas within the site that were negatively impacted by former base operations. The first was an area of buried debris created by the demolition of the former WWTP. The second was an area of soil and groundwater contamination likely associated with former surface disposal practices of spent solvents.
NAS Patuxent River working in partnership with NAVFAC, USEPA, and MDE conducted an extensive investigation to determine the nature and extent of debris in the subsurface and solvent in soil and groundwater. In the area of the former WWTP, effort involved employing geophysics to “look” into the ground to determine the likely volume of debris and using heavy equipment to “test-pit” the area to confirm the results of the geophysics. In the area of the spent solvents, numerous surface and subsurface soil samples were collected and analyzed and a number of monitoring wells were installed and sampled. All of the data generated from these efforts informed the Partnering Team such that they could select an environmental remedy that meets the ERP’s goals of cleaning up federal land, protecting communities, and restoring the environment, while being mindful of taxpayer resources. The recently completed removal action did just that.
Beginning in the summer of 2018, the Partnering Team’s contract partner mobilized heavy equipment to begin the removal of debris associated with the former WWTP and the contaminated soil, impacted by the spent solvents. The initial efforts included the installation of erosion and sediment controls. These measures safeguard local water quality by minimizing sediment and pollutants from entering streams, during removal activities. Once excavations began, soil from the WWTP area was carefully segregated and sampled to determine if it could be reused. Reusing clean soil saves taxpayer money and it reduces the consumption of landfill space, the production of greenhouse gases, and the potential for accidents by reducing the truck traffic that would be required to haul away the site soil and return with an equal volume of off-site soil. Similar reductions were achieved by recycling recovered metal and concrete. In the spent solvent area, all soil above the water table was removed and disposed of appropriately. The effort was completed in the fall of 2018. Soil confirmation samples from both areas showed that the removal was a success. All debris and contaminated soil was removed and the site was replanted with native vegetation. The ERP’s mission of Clean Up, Protect, and Restore was achieved and it was done so in a manner that reduced the burden to the taxpayer.
In the spent solvent area, though the soil source of solvent contamination was removed, some contamination remains in the shallow groundwater, which is not a source of drinking water. The Partnering Team is currently evaluating restoration options and will select one after consultation with the public.
NAS Patuxent River is located in St. Mary’s County, Maryland, approximately 65 miles southeast of Washington, D.C. The facility encompasses approximately 7,900 acres, including both the primary NAS parcel at the confluence of the Patuxent River and the Chesapeake Bay, and Webster Field Annex, an outlying parcel located in St. Inigoes, Maryland, approximately eight miles south of the NAS.
NAS Patuxent River is bounded on the north, east, and southeast by more than 11.7 miles of shoreline, ranging from sandy beaches to tidal marshes. Maryland State Highway 235 and the town of Lexington Park, an unincorporated community, border the station to the west and southwest.
NAS Patuxent River was commissioned on April 1, 1943, in an effort to centralize widely dispersed air testing facilities that had been established prior to World War II. This consolidation effort was swift, and the farming operations at Cedar Point, Maryland, were replaced by flight test operations within a year after ground breaking for construction in 1942. The U.S. Naval Test Pilot School was established in 1958. In 1975, the Naval Air Test Center began to assume its role as the principal site for Naval Air Systems Command development testing. Test facilities were upgraded in the late 1970s, with some of the largest construction appropriations in the history of the base.
As a recipient activity during three successive rounds of base realignment and closure in the 1990s, NAS Patuxent River became the fastest-growing installation in the Department of Defense (DoD). This growth resulted in a large investment in new and renovated facilities and infrastructure at NAS Patuxent River. In addition to construction investments, the station obtained Webster Field Annex for use as an outlying airfield. As a result of the consolidation that occurred throughout the 1990s, the Naval Aviation Systems Team at NAS Patuxent River now hosts the full spectrum of acquisition management, research and development capabilities, air and ground testing and evaluation, aircraft logistics, and maintenance management for naval aviation.