BRIDGETON TOWNSHIP, PA
On this page:
- What Has Been Done to Clean Up the Site?
- What Is the Current Site Status?
- Activity and Use Limitations
- Emergency Response and Removal
On related pages:
The Boarhead Farms Superfund Site is located on a residentially zoned property at 1310 Lonely Cottage Road in Bridgeton Township, Bucks County, Pennsylvania. The current owner, Boarhead Corporation, was incorporated and purchased the property in 1969. After purchase, Boarhead Corporation began storing and conducting activities that led to the release of hazardous substances to the environment. In 1970, a fish kill in a nearby stream was traced to releases of wastes from the site. Early investigations by the Bucks County Department of Health and the Pennsylvania Department of Environmental Resources (now Department of Environmental Protection) reported, among other observations, liquid wastes stored in 55-gallon drums, tanker trucks or trailers, and various containers, and liquid wastes pooled on the ground. Disturbed soils were observed, which inspectors believed to be indicators of buried waste.
In September 1976, approximately 34 local residents were evacuated due to the presence of sulfuric acid vapors that emanated from the site. These observations contributed to an order in October 1976 by the Bucks County Court of Common Pleas for Boarhead Corporation to remove all wastes from the site and prohibit the transport of hazardous substances onto the site at quantities greater than those that would be appropriate for normal household use. EPA has addressed the releases of hazardous substances through a variety of actions and continues to oversee on-going work, which includes but is not limited to on-going operation and maintenance of a groundwater extraction and treatment system on the site and point-of-entry treatment systems on residential potable wells both on and off the site.
What Has Been Done to Clean Up the Site?
EPA’s involvement at the site began in 1984 with the performance of preliminary assessments and site inspections, and has continued to the present date. Observations made during these assessments and inspections led to the addition of the site to the National Priorities List (NPL) in 1989.
Three removal actions were conducted in the 1990s:
- Excavation and off-site shipment of buried drums and impacted soils containing hazardous waste (1992-1993 by EPA);
- Off-site shipment of buried drums containing radioactive hazardous waste (1993 by a potentially responsible party (PRP) under EPA oversight); and
- Construction of a groundwater extraction and treatment system (1995-1997 by the U.S. Corps of Engineers).
During performance of these removal actions, EPA conducted a remedial investigation and feasibility study (RI/FS) to determine the nature and extent of contamination, evaluate risk, and assess the practicality of potential remedial alternatives. The findings of the RI/FS were used to identify remedial action objectives and select a remedy, which was presented in a November 18, 1998 Record of Decision (ROD). The remedy included the following principal components:
- Soil aeration and treatment of surface soil at two “hot spots";
- Excavation and off-site disposal of buried drums;
- Groundwater extraction and treatment using precipitation and air stripping;
- Installation of additional groundwater monitoring wells to monitor effectiveness of the remedial action;
- Maintenance of individual granular activated carbon filters installed on certain residential supply wells to prevent potential exposure to contaminated groundwater;
- Evaluation of phytoremediation treatability studies in former disposal areas to assist in the removal of contamination from groundwater; and
- Implementation of institutional controls to protect the integrity of the remedial action components.
In 2009, EPA initiated a fourth removal action to address high concentrations of trichloroethene, also known as trichloroethylene or TCE, in indoor air at the single-family residence on the site through a migration pathway known as “vapor intrusion.” Vapor intrusion occurs when organic hazardous substances, such as TCE, volatilize from the dissolved phase in groundwater into the gaseous phase and migrate upward and into overlying structures. The residence is located within the Former Source Area, a region about 20 or 25 acres in size in the central part of the Site where the releases of hazardous substances occurred and concentrations of contaminants of concern (COCs) in groundwater remain high. Groundwater contaminated with high concentrations of TCE enters two sumps in the basement, and for reasons largely related to the older construction of the residence, accumulates in basement air and subsequently, the indoor air of the living space above. TCEis one of 19 COCs selected in the remedy, and presents an acute risk at low concentrations in indoor air. Measures taken between 2009 and 2014 significantly reduced the concentrations of TCE in indoor air of the residence, but a potential risk may still exist for women of child-bearing years in certain conditions.
What Is the Current Site Status?
A group of potentially responsible parties (PRPs) is performing operation and maintenance of the remedy through an agreement with the United States Government. EPA conducts oversight of all PRP activities at the site. Maintenance of the groundwater extraction and treatment system is conducted on an on-going basis. Sampling of monitoring wells and some residential potable wells near the site occurs on a semi-annual basis. The PRPs perform annual indoor air and sub-slab vapor sampling at two off-site residences.
In 2017, the PRPs completed construction of a second interceptor trench and installation of additional groundwater extraction wells. The second trench and new wells have been connected to the extraction and treatment system and will be evaluated for effectiveness in future monitoring reports. As of 2018, the plume of contaminated groundwater is restricted to the Boarhead Farms property and appears to be decreasing in extent.
EPA completed the third five-year review (PDF) in September 2017 of the long-term cleanup action, also known as the remedial action or remedy for the site. The review declared the remedy “not protective of human health” due to a potential for unacceptable risks in the residence on the site, a situation which EPA continues to assess. However, the remedy is protective of human health and the environment for other potential receptors on and off the site.
An Action Memorandum signed on June 1, 2018 selected a removal action to address the concentrations of TCE in indoor air at the residence. EPA expects to implement the action in August or September 2018. Updates and progress on the removal action are available on EPA On-Scene Coordinator webpage for the site.
EPA has assessed the potential for vapor intrusion to occur at off-site residences, and continues to monitor the potential for exposure at the residences most likely to be impacted. No exposures due to vapor intrusion have been found to date or are reasonably expected to occur at the off-site residences.
Activity and Use Limitations
At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.
For more background, see Institutional Controls.
At this site, activity and use limitations that EPA calls institutional controls are not formally in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.
For more background, see Institutional Controls.
Under Superfund, EPA commonly supplements engineering measures with administrative measures known as institutional controls. Institutional controls play an important role in site remedies because they reduce the potential for human exposure to contamination by limiting land or resource use and guiding human behavior. Institutional controls also help protect the integrity of the remedy. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup. The institutional controls selected in the remedy were intended to prevent excavation, construction, or regrading of soils in the Former Source Area and protect the integrity of all remedy components, including but not limited to interceptor trench, groundwater monitoring wells, and water transmission lines. The existing institutional controls have not been put in place via a zoning restriction, environmental covenant, or other mechanism to date.
The third five-year review report (PDF) identified the need for additional institutional controls to restrict groundwater use or limit the potential for exposure due to vapor intrusion on the site property. EPA is in the process of adding additional institutional controls to the remedy through an Explanation of Significant Differences, and in the near future will seek a mechanism to implement all controls.
Emergency Response and Removal
Site cleanup has included removal actions, or short-term cleanups, to address immediate threats to human health and the environment. These actions included the removal of over 2,500 drums and numerous tanker trucks from the site; construction of a groundwater collection and treatment system; installation of extraction wells, an interceptor trench and residential well treatment filters; and the identification, excavation and removal of drums and soils contaminated with radioactive waste.
Removal actions have also included steps taken to mitigate vapor intrusion in the on-site residence. On June 1, 2018, EPA signed an Action Memorandum to address the vapor intrusion issue in the on-site residence. EPA anticipates implementing the action in August or September 2018.