Superfund Information Systems: Site Profile

Superfund Site:

CHEM-SOLV, INC.
DOVER, DE

Cleanup Activities

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Background

• The Chem-Solv, Inc. site is located on a 1.5-acre property in Cheswold, Delaware.  Chem-Solv was a small solvent distillation facility beginning in 1982.
• The facility recycled waste solvents, but in 1984 an explosion and fire at the site destroyed the facility.  Witnesses, at the time, saw fluids flowing off a concrete pad and into the soil.
• After the fire, authorities evaluated the Columbia Aquifer beneath the site and found high concentrations of volatile organic compounds (VOCs), primarly TCE, were found in the aquifer.
• In 1995, TCE was found in a private water supply well located immediately downhill from the facility, at levels 200 times greater than the drinking water standard.
• The total population of Cheswold is about 300 residents.

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What Is Being Done to Clean Up the Site?

  • The site is being addressed through federal, state and potentially responsible party (PRP) actions.
  • Goundwater recovery and treatment began in 1997, and after 48 million gallons of contaminated groundwater was treated, the pumping was conditionally stoppped based on great improvement in groundwater quality. Later, based on higher contaminant concentrations, the pumping was resumed.
  • PRPs continue to monitor domestic, recovery and monitoring wells until cleanup levels are met.
  • A groundwater management zone has been established which restricts groundwater use until cleanup levels are achieved. As required by the ROD, the PRPs immediately provided bottle water to the owners of the contaminated private wells.
  • In 1996-1998, the PRPs replaced two private wells with wells that tap a deeper, uncontaminated aquifer, and replaced six contaminated private wells downgradient of the site, with deeper wells.
  • EPA has conducted several five-year reviews of the site’s remedy. These reviews ensure that the remedies put in place protect public health and the environment, and function as intended by site decision documents. The most recent review concluded that response actions at the site are in accordance with the remedy selected by EPA and that the remedy continues to be protective of human health and the environment in the short term.
  • Continued protectiveness of the remedy requires sampling of a newly identified residential well as part of the semi-annual sampling program; assessing whether the groundwater treatment system is effectively capturing the contamination; and reviewing new state maximum contaminant levels for site contaminants and revising cleanup goals, if necessary. It also requires analyzing groundwater samples for manganese; analyzing treated groundwater for metals and determining if additional treatment is necessary; continuing to analyze groundwater and effluent; evaluating existing site data for dioxin to confirm that the implemented remedy is protective; and conducting sampling for dioxin, if necessary.

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What Is the Current Site Status?

  • The site’s long-term remedy included recovering contaminated groundwater; implementing groundwater use restrictions; providing bottled water to the owners of the contaminated private wells; and replacing contaminated private wells. Construction of the remedy took place between 1997 and 1998. 
  • PRPs continue to monitor domestic, recovery and monitoring wells until cleanup levels are met.  A groundwater management zone has been established which restricts groundwater use until cleanup levels are acheived.

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EPA’s Involvement at the Site

NPL Listing History
Status: Proposed: January 1987
Deleted: Added: August 1990

  • In 1985, the state excavated and treated 1,300 cubic yards of contaminated soil and installed a groundwater recovery system which it operated from 1985 to 1988.  The system reduced the TCE concentrations from the 200-300 parts per million range to the 1 part per million range.
  • In March 1992, EPA issued a Record of Decision (ROD) which requires additional recovery of contaminated groundwater in order to reduce contaminant concentrations in the Columbia Aquifer to the level of drinking water standards.  The ROD also restrcts the use of groundwater in the contaminated aquifer until cleanup levels are achieved.  It also provided for an alternate water supply to area residents, if necessary.
  • In 1992, EPA issued an order to 33 companies (potentially responsible parties - PRPs) requiring them to carry out the cleanup layed out in the ROD.
  • Groundwater recovery and treatment begain in 1997, and after 48 million gallons of contaminated groundwater was treated, the pumping was conditionally stoppped based on great improvement in groundwater quality.  Later, based on higher contaminant concentrations, the pumping was resumed.
  • As required by the ROD, the PRPs immediately provided bottle water to the owners of the contaminated private wells.  In 1996-1998, the PRPs replaced two private wells with wells that tap a deeper, uncontaminated aquifer, and replaced six uncontaminated private wells downgradient of the site, with deeper wells.

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Activity and Use Limitations

At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.

For more background, see Institutional Controls.

The Columbia Aquifer beneath the site has high concentrations of volatile organic compounds (VOCs), primarly TCE.Contaminant descriptions and associated risk factors are available at the Agency for Toxic Substances and Disease Registry web site at: www.atsdr.cdc.gov/toxfaqs/index.asp.

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