Army Creek Landfill
EPA ID: DED980494496
Route 13 & Route 40 New Castle, DE 19720
New Castle County
2 miles southwest of city of New Castle
Congressional District: 1st
Other Names: Llangollen Landfill
Last Updated: April 2014
The EPA is dedicated to providing you with timely and accurate information about our work at this site. If you have any questions or concerns, please contact:
On This Page
- The U.S. Environmental Protection Agency has overseen all cleanup construction activities for this site.
- In 1993, a multi-layer cap over the 50-acre landfill was completed.
- From 1993 to 2004, a groundwater collection and treatment system was operated at the site.
- In 2004, groundwater recovery operations were shifted to the adjacent Delaware Sand & Gravel Landfill site.
- Groundwater continues to be monitored semi-annually; the surface water and sediment of Army Creek are monitored every five years.
- The Army Creek Landfill, located in New Castle County, Delaware, is an abandoned sand and gravel quarry that was operated by New Castle County ("County") from 1960 through 1968 for the disposal of 1.9 million cubic yards of municipal and industrial waste.
- The site is bordered to the south and east by Army Creek, which discharges into the Delaware River one mile to the east. Another National Priorities List ("NPL") site, the Delaware Sand & Gravel Landfill, is located immediately across Army Creek to the east of the site.
- The Artesian Water Company (“Artesian”) maintains a public drinking water supply well field one-half mile downgradient of the site, serving approximately 5,000 residential customers.
- In 1971, groundwater contamination was discovered in a residential well located in the adjacent Llangollen Estates housing development. Subsequent investigation of the underlying Upper Potomac aquifer identified a plume of organic (e.g., benzene, bis(2-chloroethyl)ether ("BCEE"), 1, 2-dichloroethane and methylene chloride) and inorganic (iron and manganese) chemicals migrating from the landfills.
NPL Listing History
|Status: Final||Added: September 1983|
- A series of groundwater recovery wells between the landfills and the public water supply wells was installed by New Castle County to minimize the immediate threat. During the 1970's and 1980's, groundwater was pumped from these wells and discharged directly into Army Creek.
- On December 20, 1982, this site was proposed to the National Priorities List of the most serious uncontrolled or abandoned hazardous waste sites requiring long term remedial action.
- On September 8, 1983, the site was formally added to the list, making it eligible for federal cleanup funds.
- In June 1990, the final cleanup decision was issued by EPA.
- In September 1990, 18 potentially responsible parties ("PRPs"), including BP America, Chrysler, Du Pont, General Motors, ICI Americas, Hercules, New Castle County and Waste Management, entered into a mixed-funding Consent Decree whereby the PRPs agreed to implement the final remedy. Construction of a multi-layer cap over the 50-acre landfill began in 1992 and was completed in 1993.
- During cap construction several “nests” of buried drums, totaling approximately 100 and containing volatile and semi-volatile organic compounds, were discovered, removed and transported to a permitted hazardous waste treatment, storage and disposal facilities.
- In 1992, construction of an on-site water treatment facility began and was completed in 1993.
- The groundwater extraction system was designed to capture a co-mingled contaminant plume migrating from both the Army Creek and Delaware Sand & Gravel NPL sites.
- The water treatment facility was designed to remove iron, which is harmful to stream life, from extracted groundwater prior to its discharge to Army Creek.
- In 2004, the treatment plant was shut down and groundwater recovery operations were shifted to the Delaware Sand & Gravel Landfill site which is the source of the BCEE contamination.
- The groundwater recovered from the Delaware Sand & Gravel Landfill site is discharged to the County's wastewater treatment plant located in Wilmington.
- Organic compounds (e.g., benzene, 1,2-dichloroethane, and BCEE) and inorganic chemicals (e.g., iron and manganese) are currently found in groundwater underlying or downgradient of the Army Creek Landfill and Delaware Sand & Gravel Landfill sites.
- Groundwater recovery wells were installed and operated in order to prevent contaminants from the sites from reaching public water supply wells.
- Despite this effort, BCEE was detected in groundwater in Artesian's Llagollen Wellfield in 1999. In 2000, Delaware's Division of Public Health established an interim advisory level for BCEE in public drinking water supplies and Artesian installed a treatment system to remove BCEE from the groundwater withdrawn from the Llagollen wellfield.
- 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 Army Creek Landfill site, go to EPA’s Administrative Record Database.
- All documents and reports can also be reviewed in person at these locations:
Delaware Department of Natural Resources
& Environmental Control Site
Information and Restoration Branch
391 Lukens Drive New Castle, DE 19720-2774
U.S. EPA Region III
1650 Arch Street-6th Floor
Philadelphia, PA 19103
Call for an appointment.
- Some of the site’s key documents of interest are accessible below.
October 2010 - Post-Remediation Monitoring Report (PDF) (46 pp, 5.87MB)
April 2011 - Post-Remediation Monitoring Report (PDF) (68 pp, 5.46MB)
October 2011 - Post-Remediation Monitoring Report (PDF) (95 pp, 4.13MB)
April 2012 - Post-Remediation Monitoring Report (PDF) (51 pp, 6.11MB)
- Submit a FOIA Request
Get instructions on how to submit a FOIA request. $Fee$ for requests over 100 pages.
|Landfill cover blooming with spring wildflowers.||Landfill cover drainage ditch.||Sedimentation pond.|
(Click on a thumbnail to enlarge the photo)
- Site Progress Profile — a quick reference sheet, linking to EPA's Headquarters.
- Fact Sheets
March 2010 (PDF) (2 pp, 468k)
July 2009 (PDF) (4 pp, 106k)
April 2004 (PDF) (1 p, 75.7k)
Focus on Public Water Supply Fact Sheet 10/01 (PDF) (6 pp, 1.63MB)
- Press Releases
09/08/1998: EPA Reimburses New Castle County for Landfill Cleanup Costs