The Environmental Protection Agency on Friday removed a former manufacturing site in Petaluma from the national Superfund list, ending a three-decade effort to identify and cleanse toxic chemicals from the property.
"The cleanup of this site is an example of how state, local, and federal environmental regulators can work together with a responsible party to address contamination and safeguard local water supplies," EPA Regional Administrator Jared Blumenfeld said in a statement.
The 35-acre site along Lakeville Highway was used by Sola Optical to produce eyeglass lenses from 1978 to 2001, when the company sold the property. The buildings have since been reused by other commercial tenants.
In 1982, the California Department of Health identified acetone in a well on the property. Sola found soil around six underground solvent storage tanks was contaminated with volatile organic compounds. Three years later, the company removed the tanks and discovered the shallow groundwater underneath the site was also contaminated.
The state also found low levels of solvents in a Petaluma city well about 500 feet from the site and the well was shut down.
It was determined that chlorinated solvents and other chemicals were released into the soil and groundwater as a result of Sola's manufacturing processes. The site was placed on the federal Superfund list in 1990.
Under the oversight of the EPA and the California Regional Water Quality Control Board, Sola completed an investigation and initial soil removal. In 1991, the EPA issued a final cleanup plan to remove the contamination from the groundwater and to prevent the well from being contaminated.
In 2005, a five-year review by the EPA concluded that the remedies in place had reduced contamination to levels below drinking-water standards.
Last year, the groundwater was found to meet all cleanup goals and monitoring data showed the site no longer posed a current or future threat to human health and the environment, the EPA said.
"EPA is known for adding sites to the Superfund list, but our ultimate goal is to clean them up so that we can take them off the list," Blumenfeld said in a statement.