Duncan Oil Co Sia is a superfund site located at E1/4 Of Sec10 T2n R4e, Iuka Twp, IL 62849. The Environmental Protection Agency (EPA) identifies sites such as Duncan Oil Co Sia 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. Duncan Oil Co Sia is currently registered as an Archived superfund site by the EPA and does not require any clean up action or further investigation at this time.