Detection of man-made chemical triggers further water testing
Thu, 04/18/2013 - 9:41am
Madison Water Utility is planning additional testing after traces of the chemical 1,4 dioxane were detected in four of the city's water wells. 1,4 dioxane is a man-made chemical that's often used as a stabilizer for the solvent trichloroethane.
"I was surprised and disappointed," says Joe Grande, water quality manager for the utility.
Last winter, Grande tested various wells for 28 separate chemical contaminants, including 1,4 dioxane. The EPA is requiring water utilities across the country to test for the chemicals. Madison's tests aren't required until 2015, but the water utility decided to conduct them early.
"We wanted to get ahead of the curve," Grande says, pointing out that the tests also revealed some good news. "We didn't find hormones - not in the production wells, not in any of the monitoring wells. There's also a group of perfluorinated compounds (PFCs). These are compounds that are anti-stick, anti-grease. We tested four wells and they weren't present in any of those wells."
None of the 28 substances are currently regulated by the EPA, but the agency has classified 1,4 dioxane as a probable carcinogen. According to the watchdog group Campaign for Safe Cosmetics, it's also been found in many shampoos and soaps.
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
Grande cautions that so far, there is no evidence to suggest that the low levels of 1,4 dioxane detected create any kind of significant health risk. Madison's water currently meets all Safe Drinking Water Act requirements and all federal and state drinking water standards.
"We as a utility are concerned that (1,4 dioxane) is present. We'll continue to monitor it," he says. "If we see any changes in the concentration, if we see significant increases…it's something that may warrant additional action."
The test results were discussed at a Water Quality Advisory Committee meeting on April 9th, which was open to the public. The committee decided to conduct further tests on all 22 wells as a precaution. Those results should be available by the fall.
- Amy Barrilleaux, (608) 266-9129