Ontonagan High School Mercury is a superfund site located at 701 Parker Avenue, Ontonagan, MI 49953. The Environmental Protection Agency (EPA) identifies sites such as Ontonagan High School Mercury 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. Ontonagan High School Mercury 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.