Mercury Sw 21st Street is a superfund site located at 5515 Sw 21st Street, Topeka , KS 66614. The Environmental Protection Agency (EPA) identifies sites such as Mercury Sw 21st Street 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. Mercury Sw 21st Street 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.