HIDDEN LANE LANDFILL
On this page:
- What Is Being Done to Clean Up the Site?
- What Is the Current Site Status?
- EPA’s Involvement at the Site
- Sampling and Monitoring
- Enforcement Information
- Operable Units (opens new page)
- Cleanup Progress (opens new page)
The Hidden Lane Landfill was a 25-acre privately owned and operated disposal facility north of Virginia Route 7 between the Broad Run Farms and Countryside communities. It is immediately adjacent to the floodplain of the Potomac River. Starting in 1971 the facility accepted a variety of solid wastes including construction and demolition wastes, land clearing wastes and other items such as appliances, tires, paper, and cardboard. The county closed down the facility in 1984, pursuant to a local court decision the year before. The Hidden Lane Landfill had been named by county and state health officials as the likely source of the degreasing solvent trichloroethylene, first detected in drinking water wells of some homes in the Broad Run Farms subdivision just west of the landfill in 1989. . Hidden Lane Landfill was listed on the National Priorities List in March 2008.
What Is Being Done to Clean Up the Site?
- The site is being addressed through state and federal actions.
- The Loudoun County Department of Health collected 67 samples from private wells in the Broad Run Farms area, searching for trichloroethylene (TCE) and other contaminants.
- The community to the east, Countryside, was not sampled because the homes in that subdivision use public drinking water.
- Data results indicated that 22 homes had TCE in their private wells; of those 16 were above safe drinking water levels.
- Funds from the Virginia Environmental Emergency Fund were used to install a total of 26 whole house carbon filtration units for homes that had detectable levels of TCE in their wells. The DEQ also performed more than two years of operation and maintenance on the filtration units, including several rounds of sampling to ensure that the units are working properly.
- EPA assumed responsibility for these systems from VDEQ on July 1, 2008 and has offered support for several other property owners who chose to install such systems on their own.
- EPA continues to test these systems quarterly and maintain them to ensure they are operating properly.
What Is the Current Site Status?
- EPA has confirmed that the plume moves generally north from the Landfill in the direction of the Potomac River.
- EPA completed the human health risk assessment at the Site in 2013, the ecological risk assessment in 2014, then began developing remedial alternatives to be evaluated during the Feasibility Study.
- EPA will use this information and the results of the treatability study to develop a cleanup approach for the Site beginning in 2015.
EPA’s Involvement at the Site
- EPA began conducting the Remedial Investigation at the Site in 2008 with sampling and maintenance of the landfill gas monitoring system. No significant detections of landfill gas have been recorded since sampling began.
- Initial field work for the groundwater investigation began in January 2009. The first stage of monitoring well drilling and installation was completed in late spring 2009.
- EPA completed its first round of surface water sampling in early Summer 2009 and two rounds of groundwater (well) sampling in late 2009. EPA evaluated those results and concluded that a series of nine deeper monitoring wells needed to be installed to 350 feet below ground surface (bgs) to better characterize the groundwater contamination. EPA began installing those deeper wells in late summer 2010 and completed the work, including sampling and analysis, in 2011.
- As a result, EPA developed much better picture of the location of the TCE-contaminated groundwater plume, but still needed to confirm the depth and direction of the plume below ground.
- EPA began deepening three of the nine wells installed to a depth of 500 feet bgs.
- Test results from the deeper monitoring wells show the location, depth and movement of the TCE plume.
Sampling and Monitoring
During cleanup, a site can be divided into a number of distinct areas depending on its complexity. These areas, called operable units (OUs), may address geographic areas, specific problems, or areas where a specific action is required. Examples of typical operable units include construction of a groundwater pump and treatment system or construction of a cap over a landfill.