The EPA removes one site and part of another in Delaware from its list of the nation’s most contaminated sites.
The Chem-Solv site in Cheswold was dropped from the Superfund National Priorities List along with a portion of the Tybouts Corner Landfill site in New Castle.
Sites or parts of sites are deleted from the list when no further cleanup is required to protect human health or the environment.
The Chem-Solv site in Cheswold opened in 1982 as a small solvent distillation facility, but in 1984 an explosion and fire destroyed the facility.
After the fire, authorities evaluated the Columbia Aquifer beneath the site and high concentrations of volatile organic compounds.
Groundwater was removed and purified from 1997 to 2017, and in 2017 a sampling showed concentrations had dropped below EPA thresholds and groundwater extraction and treatment was conditionally discontinued.
Since then, quarterly sampling showed all contaminants remained below EPA’s federal groundwater quality standards. Based on that monitoring, Chem-Solv is coming off the list.
As for the Tybouts Corner Landfill Site, it was used by the New Castle County Department of Public Works from December 1968 until July 1971, and it consisted of two non-adjoined sections, the West Landfill and Main Landfill.
Contamination was found in two nearby wells in 1976 and in 1983. The clean-up of two parcels of the West Landfill is considered complete which included removal of all waste as well as soil and groundwater remediation.
Significant progress has been made in the clean-up of the Main Landfill portion, but all performance standards have not yet been achieved. So, it remains on the list.
