Pease Air Force Base is a superfund site located at 509 Csg/cc, Portsmouth/newington, NH 03803. The Environmental Protection Agency (EPA) identifies sites such as Pease Air Force Base 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. Pease Air Force Base is currently registered as an Active NPL superfund site by the EPA. Because it is on the NPL (National Priorities List), Pease Air Force Base is considered one of the worst hazardous waste sites identified by the EPA.