Mid-Atlantic Superfund

EPA Region 3 (Mid-Atlantic)

Pennsylvania
Montgomery County
Norristown

EPA ID# PAD093730174

7th Congressional District

Last Update: September 2009

Other Names

Commodore Business Machines

Current Site Status

Construction of a groundwater treatment system was completed in August 2000. The U.S. Environmental Protection Agency is overseeing current cleanup activities at the Commodore Semiconductor Group site by the Potentially Responsible Party (PRP), Rockwell Automation formerly known as Allen-Bradley, LLC. The remedy for the site included, among other things, a groundwater pump and treat system and the extension of an existing waterline to twelve residences along Rittenhouse and Audubon Roads. The waterline extension was formerly turned over to the Audubon Water Company. The system pumps and treats approximately 85 gallons per minute of contaminated groundwater. Rockwell conducts groundwater sampling semi-annually to monitor the effectiveness of the groundwater treatment system.

Site Description

The Commodore Semiconductor Group site, which is located in Norristown, Montgomery County, Pennsylvania was operated as a computer chip manufacturing facility from 1970 to 1992 by Commodore Business Machines. Waste solvents were stored in an underground concrete storage tank on site until 1975, when it was taken out of service. An unlined steel tank was installed next to the concrete one in 1975. Inspections conducted by the Pennsylvania Department of Environmental Protection indicated that both tanks leaked. The majority of residences in the area are connected to a privately-owned public water supply, however, a small number of individuals still have operational private wells.

Site Responsibility

Cleanup of this site is the responsibility of Federal and State governements, and parties potentially responsible for site contamination.

NPL Listing History

Our country's most serious, uncontrolled, or abandoned hazardous waste sites can be cleaned using federal money. To be eligible for federal cleanup money, a site must be put on the National Priorities List. This site was proposed to the list on January 22, 1987 and formally added to the list October 4, 1989.

Threats and Contaminants

On-site groundwater is contaminated with high levels of trichloroethylene (TCE) and other VOCs from the waste solvents that leaked from the underground storage tanks. TCE was also found in on-site soils but not at levels of concern. Accidental swallowing or contact with contaminated groundwater on the site may pose health risks, however, exposure pathways to this underground water have been removed.

Contaminant descriptions and risk factors are available from the Agency for Toxic Substances and Disease Registry, an arm of the CDC.

Cleanup Progress

In 1981, Commodore excavated soils and pumped water from a contaminated well, then sprayed it onto surrounding fields. The VOCs dissipated into the air. Since 1984, air strippers have been in use to remove solvents from the groundwater. Air strippers have been installed on all affected public wells through agreements between Commodore and the local water authority. Also in 1984 household carbon units were installed at residences where at least 1 part per billion of VOC was detected. Other work done at the site included, groundwater extraction and treatment, extension of the existing water line to affected residences, and continued maintenance of hold house carbon units. On June 29, 1993, EPA issued a unilateral order to Commodore Business Machines, and Allen-Bradley Corporation to carry out this work. Only Allen-Bradley Corporation has complied with the order. Commodore Business Machines went bankrupt.

The waterline extension and laterals to the residences were completed in January 1997. Transfer of the ownership of the waterline extension from Allen Bradley Corporation to Audubon Water Company was completed in December 1997. The connection of the residences and the closing of the residential wells began in January 1998.

Construction of the groundwater extraction and treatment system began in the Fall of 1999. In February 2000, pipelines and underground wiring were installed, pumps were installed at each of the extraction wells, and the treatment building was constructed. The treatment process equipment was installed in May 2000. Preliminary start-up and testing of the system began in August 2000.

In September 2003, Rockwell Automation completed additional work to enhance and speed up the groundwater treatment. This enhanced treatment (ET) included the installation of a full-scale vapor extraction system to remove chemical vapors from the soil and bedrock, and chemical oxidation to treat residual contaminant levels in soil near and beneath the building. Rockwell continues to coordinate with EPA and PADEP and intends to continue accelerating cleanup. Based on the positive results from the ET, Rockwell Automation will be further investigating contamination beneath the existing building.

In August 2005, EPA completed the First Five-Year Review of the remedy and found that the implemented remedy is currently protective in the short-term as there is no current exposure to Site COCs and that long-term protectiveness of the remedy will be achieved by continuing to pump and treat the groundwater and maintaining effective institutional controls until cleanup standards are achieved.

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Site Contacts

Administrative Record Locations