MADISON (WKOW) -- The City of Madison Water Utility is testing the city's water supply after a probable carcinogen was found in four of the city's wells.
Initial tests detected the chemical 1,4 dioxane in three wells on the east side and one on the west side. The utility is going to test all 22 wells as a precaution.
According to the Environmental Protection Agency, 1,4 dioxane is used as a solvent for things like resins, oils, waxes, some dyes and other organic and inorganic compounds.
The Madison Water Utility says there is no evidence to suggest the low levels of the chemical create any kind of significant health risk.
Because there is no federal drinking water standard for 1,4 dioxane, a handful of states have created their own guidelines. The Office of Environmental Health Hazard Assessment reports that the states of Michigan, North Carolina, Connecticut, and Minnesota have set safety levels at 2 parts per billion (ppb), 7 ppb, 20 ppb, and 30 ppb respectively. The state of California has set an advisory action level of 3 ppb.
Madison Water Utility tests revealed trace amounts of 1,4 dioxane at the following levels:
Well 9 (Spaanem Ave.): 0.12 ppb
Well 11 (near east side Woodman's): 0.39 - 0.63 ppb
Well 14 (University Ave. near Whitney Way): 0.29 ppb
Well 15 (E. Washington near Lien Rd.): 0.17 ppb
The utility says the city's water meets all state and federal drinking water standards.