Standard Chlorine of Delaware, Inc.
New Castle County, Del.	
Site Description
Standard Chlorine of Delaware is a 65-acre site located in New Castle County, Del. EPA added the site to the
National Priorities List in 1987. From 1966-2002, it housed a large chemical plant that made industrial
quantities of cholorobenzene-based liquids, which are poisonous to humans and animals. The liquids were
also stored in on-site tanks. Two accidents at the site (in 1981 and 1986) resulted in the spillage of more than
574,000 gallons of chemical products, which contaminated local soil, surface water, groundwater and
sediments. The spills contaminated nearby wetlands, aquifers and creeks.
Current Site Status and Cleanup Actions to Date
•	EPA divided the site into four cleanup projects, including an interim groundwater remedy, which has
already been implemented. The interim action included containment and treatment of groundwater,
treatment of air emissions resulting from the groundwater treatment process, source removal of dense
non-aqueous phase liquids (DNAPLS) and further investigation of groundwater and DNAPLs. This
action also included the removal and off-site incineration of approximately 1.3 million gallons of bulk
liquid chemicals.
•	From 2002 to 2006, EPA's removal program took over operation of the bankrupted facility and
processed more than 40 million pounds of chemicals. EPA managed the on-site processing, sale
and/or disposal of the chemicals while also overseeing the dismantlement of the chemical plant.
•	As of 2009, EPA had removed approximately 3,400 totes of bulk liquid chemicals.
•	In 2009, EPA accomplished additional cleanup actions with American Reinvestment and Recovery Act
funds by completing removal of the remaining 800 totes of bulk liquid chemicals and upgrading the
groundwater treatment system.
•	In 2012, EPA dismantled the remaining warehouse in preparation for capping the former chemical
plant area.
•	EPA has determined that all unacceptable human exposure pathways have been eliminated, and
therefore, under current conditions, human exposure is under control site wide. EPA is continuing
investigations in the contaminated wetlands and underlying Columbia and Potomac aquifers.
Unfunded Action
Fiscal Year 2013 work that was not funded involved the capping of the former chemical plant area, soil gas
treatment and implementation of institutional controls.
Current Funding Status
To date, EPA has spent approximately $56.3 million on construction work at the site.
For more information on this site, please read the Standard Chlorine site information on the Region 3
Superfund web site.

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