An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Hazardous Waste Cleanup: Atlantic Coast Environmental, Incorporated in Dover, Delaware

On this page:

Atlantic Coast Environmental, Inc. (ACE) is a closed hazardous water management facility located approximately 0.2 miles northwest of the city limits of Dover, Delaware.

Cleanup Status

The Delaware Department of Natural Resources and Environmental Control (DNREC) issued a Post-Closure Permit (PCP) for a closed waste pile to ACE in 1996. The permit requires ACE to conduct thirty (30) years of post-closure care with site maintenance, measures to control erosion to the waste pile cap, an inspection and security program, groundwater monitoring using alternate concentration limits that protect environmental resources, and financial assurances.

The Post-Closure Permit stipulated that ACE would conduct ground water monitoring during the compliance period, which ran from 1990-98. The PCP also stipulated that DNREC would evaluate the need for additional ground water monitoring at the end of the compliance period. DNREC has determined that additional monitoring will be required for the remainder of the post-closure care period (present-2019). However, because the ground water protection standard has not been exceeded for an extended period of time (i.e., the last six consecutive years of sampling), DNREC has significantly reduced the frequency of sampling. Four sampling events, spaced at approximate five-year intervals, will be required for the balance of the post-closure care period.

Remaining requirements of the Post-Closure Permit will continue to be fulfilled.

Top of Page

Site Description

Interactive Map of Atlantic Coast Environmental, Incorporated, Dover, Delaware

View larger map

Atlantic Coast Environmental, Inc. (ACE) is a closed hazardous water management facility located approximately 0.2 miles northwest of the city limits of Dover, Delaware. ACE is accessed via a private, unpaved road, and sets back approximately ½ mile northwest of the intersection of Sate Road 99 (College Road) and Pennsylvania Railroad Company train tracks. The site is bounded by wooded areas to the north and northeast, the former Eastern Disposal landfill to the east, an overgrown field to the south, and property own by Conrail to the west (railroad tracks). The ACE facility was operated under Resource Conservation and Recovery Act (RCRA) interim status as a solidification and transfer facility for hazardous waste from 1981 to 1984. Bulk wastes were reportedly received in roll-off boxes and stored on concrete pads in a Process Bulking Unit.

These wastes were solidified in roll-off boxes using fly ash. After solidification, waste was transferred to the 20 by 40-foot Waste Pile Storage Unit. Wastes contained in this pile were subsequently placed in shipping containers for transfer to off-site disposal facilities.

The ACE property is approximately 4.6 acres in size. Buildings and structures which comprised the former facility are within an approximately 300 by 300 foot area enclosed by a six-foot high chain link fence topped with barb-wire. However, nearly all of the structures existing during ACE operations have been removed.

A closure plan for the Waste Pile Storage Unit was submitted to DNREC in 1985. Closure activities included excavation and off-site disposal of soil beneath and adjacent to the concrete pad. In addition, soils were excavated from the area north and east of the Storage Facility. Due to the presence of some residual soil contamination in this area, DNREC required capping of this unit. A 40 by 40 foot capped area (seven foot thick) was completed in 1988. On November 29, 1989, ACE completed closure of the waste pile storage unit. A Post-closure permit was issued in 1996 for the waste pile unit. A closure plan was submitted for the Process Bulking Unit to DNREC in 1995. Since waste material and containers used in the Process Bulking Unit were removed from the site in 1984, post-closure care was not required.

Quarterly groundwater sampling was initiated at the site in April 1990, as a requirement for addressing closure and post-closure activities. However, as sampling results continuously showed significant decrease in impact to ground water, sampling frequency was reduced to semi-annually in 1994 and annually in 1996.The Ground Water Monitoring Plan (GWMP) approved by DNREC for the facility was developed to assess potential impacts from the entire facility, including the former Waste Pile Storage Unit.

Top of Page

Contaminants at this Facility

The main contaminants in the groundwater are trichloroethylene, tetrachloroethylene, 1,1,2 trichloroethane, 1,1,2,2-tetrachloroethane, and chloroform. Alternate Concentration Limits were established in 1994 for the first four analytes.

Top of Page

Institutional and Engineering Controls at this Facility

There are no current or future land use restrictions within the permit, other than a requirement that no use shall be allowed which would disturb the integrity of the final cover, containment system components, or the function of the monitoring systems. However, the permit does state that if the permittee or owner of the land wishes to remove the cap or contaminated soils, they must request a modification and must demonstrate that the removal of hazardous waste will satisfy the criteria of 264.111, 264.117(c), and 264.119(c). Department of Natural Resources and Environmental Control (DNREC) stated that they will evaluate the site for the potential implementation of covenants or institutional controls (ICs) at the end of the permit in 2019.

    Top of Page

    Land Reuse Information at this Facility

    The site is currently unused.

    Top of Page

    Site Responsiblity at this Facility

    RCRA Corrective Action activities are being conducted under the direction of the Delaware Department of Natural Resources and Environmental Control with assistance from EPA Region 3.

    Top of Page