The Queensbury landfill on Jenkinsville Road has been designated a potential state Superfund site. DEC is now in charge of investigating the site and determining whether it is the cause of 1,4-dioxane found in nearby residential wells. The Post Star reports the state Department of Health has also tested many more wells in the nearby neighborhood and will extend the tests further if more wells test positive for dioxane, which was used as a stabilizer for chlorinated solvents.