Concentration of 1,4-Dioxane in Wells Sampled During 2002-2009 in the Vicinity of the Tucson International Airport Area Superfund Site, Arizona

Extensive groundwater contamination resulting from industrial activities led to the listing of the Tucson International Airport Area as a Superfund Site in 1983. Early investigations revealed elevated levels of volatile organic compounds (VOCs) including the chlorinated solvents trichloroethylene (TCE) and perchloroethylene (PCE) in wells in the area. Several responsible parties were identified and cleanup activities were begun in the late 1980s using technology designed for removal of VOCs. In 2002, the compound 1,4-dioxane was discovered in wells in the Tucson Airport Remediation Project (TARP) area. Since then, 1,4-dioxane has been detected throughout the TARP area, in some cases exceeding the U.S. Environmental Protection Agency (USEPA) drinking water advisory level of 3 ?g/L.