Delaware County Sewage Treatment Plant is a superfund site located at Calcon Hook Road, Darby Twp, PA 19023. The Environmental Protection Agency (EPA) identifies sites such as Delaware County Sewage Treatment Plant because they pose or had once posed a potential risk to human health and/or the environment due to contamination by one or more hazardous wastes. Delaware County Sewage Treatment Plant is currently registered as an Active superfund site by the EPA. However, it is not on the NPL (National Priorities List), which means the EPA does not consider it one of the nation's most hazardous waste sites.