Superfund Site: DOVER GAS LIGHT CO.

Superfund Site Profile

In September 2015, EPA will begin a Feasibility Study at the Dover Gas Light Site to determine the best approaches to address groundwater contamination at the Site. That effort should completed in spring 2016. Once completed, EPA will identify its preferred remedy to the public in a Proposed Remedial Action Plan (PRAP) in 2016.  After inviting and responding to public comments on the PRAP, EPA will detail the final remedy in a Record of Decision (ROD).


The 23-acre Dover Gas Light Co. site is located in Dover, Delaware. From 1859 to 1948, the Dover Gas Light Company processed coal to produce gas for use in street lamps on site. Operators buried process materials containing coal tar residues on the site. After the plant closed in 1948, all structures except a brick garage were demolished. Much of the plant was removed, but sections of the tanks and other process equipment were buried on site. These underground structures contained coal oil and/or coal tar. These waste disposal activities contaminated soil and groundwater with hazardous chemicals.

Approximately 10,000 people live within one mile of the site and an estimated 45,000 people are served by public and private wells within three miles of the site.

EPA proposed the Site to the National Priorities List (NPL) in January 1987.  It was listed on the NPL in October 1989, making it eligible for federal cleanup funds.