PADEP Update

Nockamixon TCE Hazardous Site Cleanup Act Facts

Background

The Nockamixon TCE HSCA Site is located in Nockamixon Township, Bucks County, Pennsylvania.  Chlorinated solvents have contaminated the soil, surface water, and groundwater at the Site.  DEP has identified a former 77.2-acre farm on Brennan Road as the source of the contamination.  The farm, which was subdivided into nine parcels in 1978, housed drums of unknown contents and other deposited/buried wastes.  Property owners removed the drums in 1980, but subsequent investigations revealed elevated concentrations of chlorinated solvents in the areas where the drums had been stored.

In 2009, the Bucks County Health Department notified DEP of Trichloroethene (TCE) contamination in wells serving a local restaurant and several homes. Between 2009 and 2011, DEP sampled more than 100 private drinking water wells in the area.  Chlorinated solvents, TCE, and/or Tetrachloroethene (PCE) exceeded Safe Drinking Water Maximum Contaminant Levels in wells serving 45 homes.  DEP subsequently installed carbon filter systems on 42 of those homes.

Indoor air of two residential properties near the contamination source areas was impacted by vapor intrusion (VI).  DEP subsequently installed vapor mitigation systems in those homes.

What are Chlorinated Solvents?

Chlorinated solvents such as Trichloroethylene (TCE) and Tetrachloroethylene (PCE) are commonly used in circuit board manufacturing, the textile industry, and for the removal of grease from metal parts. PCE is also used for dry cleaning.

1,4-Dioxane was used as a stabilizer for chlorinated solvents and was used in a variety of products including paint strippers, dyes, greases, varnishes, and waxes.

Chlorinated solvents are among the most common soil and groundwater contaminants.  Routes of exposure can include ingestion, inhalation, and skin contact.

Environmental Health Fact Sheets on these contaminants can be found through PA Department of Health(opens in a new tab): TCE(opens in a new tab) (PDF), PCE(opens in a new tab) (PDF), and 1,4-Dioxane(opens in a new tab) (PDF).

What is being done to clean up the Site?

Since 2009, DEP and its contractors have conducted soil, surface water, and groundwater investigations to determine the nature and extent of contamination in the Site area.

Based on these investigations, DEP has determined that the Site should be listed on the Pennsylvania Priority List of Hazardous Sites for Remedial Response (PAPL). The PAPL identifies sites that are expected to need significant resources to address threats to the public health, safety, or the environment. The Hazard Ranking System (HRS) is used to rank sites for placement on the PAPL. The HRS score is calculated from the potential for human or environmental exposure to the contaminants of concern through groundwater, surface water, air, and soil.

Nockamixon TCE HSCA Site PAPL Listing:

On January 18, 2025, DEP published a notice in the Pennsylvania Bulletin to place the Nockamixon TCE HSCA Site on the PAPL. Following listing on the PAPL, DEP will issue an Analysis of Alternatives to evaluate the potential remedies to clean up the source of the contamination.  The Analysis of Alternatives will be available for public review for 90 days.  DEP will hold a combined informational public meeting and hearing during this review period for members of the community to learn about the potential remedies and to provide comments.

The Analysis of Alternatives will incorporate information from the following documents:

  • A November 2023 Technical Screening Evaluation Memorandum (PDF) prepared by GES on behalf of DEP identified potential remedies to address contamination in source area soil, source area groundwater, and non-source area groundwater.
  • A July 2024 Remedial Alternatives Analysis Report prepared by GES on behalf of DEP describes additional source area investigation activities performed since 2021 and evaluates potential remediation alternatives.

Environmental Health Concerns:

Bucks County residents with an environmental health concern are encouraged to contact the Bucks County Health Department 215-345-3318.

Updates:

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DEP Site Related Questions:

Source: Nockamixon TCE HSCA | Department of Environmental Protection | Commonwealth of Pennsylvania