Hall Valley Mines is a superfund site located at T6s R76w Sec 14, Jefferson, CO 80456. The Environmental Protection Agency (EPA) identifies sites such as Hall Valley Mines 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. Hall Valley Mines 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.