Current Site Information
Commodore Semiconductor Group
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.
In September 2003, Rockwell Automation completed additional work to enhanced and speed up the groundwater treatment. This 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. Based on the results of this additional work Rockwell Automation plans to proceed with a pilot study of chemical oxidation of the bedrock aquifer to evaluate its effectiveness at treating the groundwater in place. EPA and the state will review the plan for approval.
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 have 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.
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 associated risk factors are available on the Agency for Toxic Substance and Disease Registry, an arm of the CDC, web site at
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 to be 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.
Remedial Project Manager
Community Involvement Coordinator
Public files (Administrative Record) on EPA’s actions and decisions for this site can be examined at the following location:
U.S. EPA Region 3
Contact Eric Jarrell at 215-278-3745
United States Environmental Protection Agency, 1650 Arch Street, Philadelphia, PA 19103-2029
This is an archive of the EPA's Commodore Semiconductor Group Superfund Site page which was removed from their website in 2014.