EPA ID: DEN000306645
Congressional District: 1st
Other Names: Millsboro Public Well TCE Site
Last Updated: January 2015
Remedial Project Manager
Community Involvement Coordinator
State and Congressional Liaison
Site Assessment Manager
Region 3 NPL Coordinator
- Community Involvement Plan - July 2014 (PDF) (59 pp, 1.77 MB)
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On This Page
- The U.S. Environmental Protection Agency (EPA) and three potentially responsible parties (PRPs) signed Administrative Orders on Consent to conduct the investigation and evaluation of cleanup options following EPA's Non-Time Critical Removal process.
- Upon completion of the Non-Time Critical Removal process the EPA will determine if further actions are warranted which may lead to finalizing the listing of the Site on EPA's National Priorities List (NPL). The NPL is a list of hazardous waste sites that may pose long-term human health or environmental risks requiring investigation under the Superfund Remedial Process.
- The State's Department of Natural Resources and Environmental Control (DNREC) performed a removal action to address soil, tanks and piping at the source area using funds from the State Hazardous Substances Control Act (HSCA).
- On May 10, 2010, the USEPA signed an Administrative Order on Consent (AOC) that was negotiated with the Potentially Responsible Parties (PRPs) for the Site.
- The PRPs (e.g., Mallinckrodt Veterinary, Inc. and Merck & Co., Inc.) assumed 1) weekly testing of the water supply system, 2) replacement of granulated activated carbon for the drinking water treatment system and 3) performance of an aquifer pump test for the newly installed drinking water supply well in April 2010.
- On February 2, 2011, the USEPA entered into a second Administrative Order on Consent (AOC) with the PRPs. The second AOC requires the PRPs to perform an engineering evaluation and cost analysis (EE/CA) to develop cleanup options to address the source area, groundwater contamination and assess vapor intrusion. If warranted, cleanup options intended to address vapor intrusion will also be developed.
- Field work to delineate the groundwater plume and source area was completed.
- Assessment of the potential for vapor intrusion was also completed. The assessment found that vapor intrusion does not pose a risk. Therefore, no further action is required to address vapor intrusion.
- Installation of a test injection well and an extraction well was completed in November 2013. The test injection well will be used to inject treated groundwater from the test extraction well to see if this is a viable option for cleaning up the contaminated groundwater. Results from the test extraction and injection system will be evaluated in the Engineering Evaluation and Cost Analysis (EE/CA) for potential use as a long-term treatment method.
- The draft EE/CA has been submitted to the EPA and DNREC for review. The Agencies expect to finalize the EE/CA and hold a public meeting to present the preferred cleanup remedy for the source area and groundwater plume in the first half of 2015.
- The Millsboro TCE Site is located approximately between S. DuPont Highway and State Street in the town of Millsboro, Sussex County, Delaware.
- The Site is approximately 1500 feet long and 300 feet wide. It consists of a source area at the intersection of Wharton Street and S. DuPont Highway, which was formerly a poultry vaccine manufacturing operation. Also included are a recovery area, located at Town of Millsboro’s Wellfield on West Church Street, and the impacted groundwater under the properties in between.
- In 1952, Delaware Poultry Laboratories, Inc. was established and poultry vaccine manufacturing operations began on the source area property.
- Through a series of ownership transfers, the facility was ultimately owned and operated by Shering Plough who demolished the building in December 2000, and sold the property to the current owner, Hiram Dennis Lasher in June 2001.
- In October 2005 the state water authority detected trichloroethylene (TCE) at a concentration that exceeded the national drinking water standard while conducting a routine water sampling at the Boys & Girls Club located in Dagsboro, Delaware.
NPL Listing History
Status: Proposed in 2009
- The public water supply systems for Millsboro and Dagsboro were taken offline after the discovery of TCE, and a public notice restricting water use was issued, on October 24, 2005.
- As a result, an alternative supply of water, in bottles or tankers, was supplied by the municipality to affected residents.
- Interim response actions were taken immediately by the Delaware Department of Natural Resources and Environmental Control (DNREC) and the Town of Millsboro (TOM). The responses included sampling domestic wells and outfitting the Millsboro public water supply wells with granulated activated carbon (GAC) filters to treat extracted groundwater at the wellhead before distribution to customers.
- The TOM also instituted a weekly public water supply well sampling and chemical analysis program to monitor for TCE and other volatile organic compounds (VOCs) and to assess the effectiveness of the GAC treatment before distribution.
- Public notices restricting water usage were lifted from Millsboro and Dagsboro in November 2005 and December 2005, respectively.
- In 2006, DNREC removed approximately 209 tons of contaminated soil, tanks, and pipes from the poultry vaccine manufacturing property.
- The Town of Millsboro is currently filtering groundwater through activated carbon to meet drinking water standards.
- The groundwater is contaminated with the solvent trichloroethylene (TCE) in the area of the Town of Millsboro's public water supply well.
- No contaminants have been found in domestic supply wells.
- People who come into direct contact with or ingest contaminated groundwater may be at risk.
- Contaminant descriptions and risk factors are available from the Agency for Toxic Substances and Disease Registry, an arm of the CDC.
- To search an on-line database of all documents and reports on the Milsboro TCE site, go to EPA’s Administrative Record Database.
- All documents and reports can also be reviewed in person at these locations:
Millsboro Public Library
217 W. State Street
Millsboro, DE 19966
U.S. EPA Region 3 NPL Public Docket
c/o U.S. EPA Region 3 Library
1650 Arch Street, 2nd floor (3PM52)
Philadelphia, PA 19103-2029
215-814-5364 or 215-814-5254
- Some of the site’s key documents of interest are accessible below.
Delaware SIRB-Related Laws, Regulations, Guidance and Policies
Millsboro TCE NPL Public Docket (EPA-HQ-SFUND-2009-0580)
Hazard Ranking System (HRS) Documentation Record (PDF) (46 pp, 272 K)*
* The documentation record provided is available at the time of proposal for informational purposes. An official copy of the documentation record and the documents referenced in it are available in the EPA Region 3 NPL Public Docket at the EPA Region 3 Library. Copies of materials in EPA's electronic docket for the site's proposal to the NPL are also accessible online through Regulations. gov under Docket ID: EPA-HQ-SFUND-2009-0580.
Consent Order - November 2010 (PDF) (7 pp, 259 K)
Consent Order - February 2011 (PDF) (39 pp, 2.06 MB)
- Submit a FOIA Request
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- Community Involement Plan - July 2014 (PDF) (59 pp, 1.77 MB)
- Federal Register
9/23/2009: National Priorities List, Proposed Rule No. 51 (74 FR 48504)
- Press Releases
9/23/2009: Millsboro TCE Site Proposed for Superfund List
9/23/2009: EPA Adds 11 Hazardous Waste Sites to Superfund's National Priorities List / EPA Also Proposes to Add 10 Additional Sites
- This site currently does not meet the criteria for Site-wide Ready for Anticipated Use; however parts of the site may be suitable for reuse.
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