Old Brine Sludge Landfill is a superfund site located at Rte 9, Delaware City, DE 19706. The Environmental Protection Agency (EPA) identifies sites such as Old Brine Sludge Landfill 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. Old Brine Sludge Landfill 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.