Skip to Page Content Governor | General Assembly | Courts | Elected Officials | State Agencies
  Photo: Featured Delaware Photo
  Phone Numbers   Mobile   Help   Size   Print   Email

Skip Navigation LinksDNREC : Division of Waste & Hazardous Substances : Site Investigation & Restoration : Hockessin Groundwater Site

 Hockessin Groundwater Site


UPDATE:   The U.S. Environmental Protection Agency (EPA) announced on May 15, 2018 that the Hockessin Groundwater Site will be added to the National Priorities List (NPL). The NPL is EPA’s list of sites eligible for remedial action financed under the federal Superfund program. The proposed listing will allow EPA to use Superfund authority and resources to work with DNREC to help resolve groundwater concerns in the Hockessin area. EPA, with support from DNREC and the Delaware Division of Public Health (DPH), and Artesian Water Company, held a public meeting on the proposed listing of the Hockessin Groundwater Site to the NPL in Feb. 2018 at Hockessin Memorial Hall. For Federal Register notices and supporting documents for the final and proposed sites, please visit:

The Hockessin Groundwater Site is located along Lancaster Pike (Route 41) in Hockessin, Delaware and encompasses numerous commercial and residential properties. DNREC's Site Investigation & Restoration Section, with support from the EPA and the Division of Public Health (DPH) and Artesian Water Company (Artesian), is investigating the site. DNREC requested federal assistance from the EPA to further investigate the area and help identify the sources of  groundwater contamination. DNREC and EPA have been investigating contamination from volatile organic compounds (VOCs) in some groundwater wells that supply the Hockessin area’s drinking water. Public drinking water in the area is provided by Artesian, and is treated to remove VOCs. The finished public drinking water continues to meet all federal and state drinking water standards, as reported in Artesian’s annual water quality reports. Agency representatives provided an update on the Hockessin Groundwater Site at the Greater Hockessin Area Development Association (GHADA) meeting June 19 at the Hockessin Memorial Hall.

The primary groundwater contaminant of concern in the Hockessin area is tetrachloroethylene (PCE), most commonly used as a dry-cleaning solvent and industrial degreaser. PCE, a VOC that can cause adverse human health effects, was identified in a commercial irrigation well, three residential wells, and several public supply wells in the Artesian’s Hockessin well field. DNREC installed water treatment systems at the three residential properties impacted by the VOC contamination.

The sources of the groundwater contamination have not been fully determined. DNREC has worked with several potential responsible parties, and has completed numerous environmental investigations and remedial efforts at sites of potential concern. Subsequently, DNREC has requested additional assistance from the EPA to help fully investigate the area, and identify the sources of the VOC contamination in groundwater.

DNREC and EPA provided information at the meeting on groundwater well testing results for residential properties, along with 2016-2017 environmental assessment work completed by EPA on  groundwater contamination in the area. The EPA is using Superfund authority and resources to determine if the site warrants further long-term investigation and cleanup. EPA’s investigations also could result in the site being listed on the National Priorities List, the list of sites eligible for remedial action financed under the federal Superfund program. DNREC, DPH, Artesian and EPA representatives were available to answer questions.

For more information regarding the site, please contact Timothy Ratsep, administrator, Site Investigation & Restoration Section; Paul Will, SIRS program manager; or Christina Wirtz, SIRS outreach ombudsman, at 302-395-2600, or by email:;  or

For more information regarding the EPA's Superfund Program, please contact: 

  • Alexander Mandell, Community Involvement Coordinator, EPA Region 3 at: 215-814-5517, or by email at:
  • Connor O’Loughlin, Site Assessment Manager, EPA Region 3 at: 215-814-3304, or by email at:
  • For media inquiries: Roy Seneca, Office of Communications and Government Relations, U.S. EPA, Region 3 at: 215-814-5567, or by email at:

Related Documents and Websites 

For more information regarding DNREC's previous investigations at the Hockessin Groundwater Site and other nearby sites , please visit  DNREC's Delaware Environmental Navigator (DEN) at: for the following sites:

  • DE-1317: Hockessin Groundwater Site
  • DE-1591: Hockessin Cleaners
  • DE-1532: Sunrise Cleaners
  • DE-1590: Thompson Dry Cleaners

For additional information or questions regarding DNREC's investigations, please contact:

For more information on the contaminants of concern in the area, primarily tetrachloroethylene (PCE) and its degradation products in groundwater - trichloroethylene (TCE), dichloroethylene (DCE) and vinyl chloride (VC) - please visit:

  • Agency for Toxic Substances & Disease Registry (ATSDR) ToxFAQs for PCE; TCE1,2 DCE and VC

For more information regarding Artesian’s drinking water supply and treatment system, please click here, or contact:


site map   |   about this site   |    contact us   |    translate   |