State might insist all municipalities treat drinking water

All municipalities in Wisconsin would have to disinfect the drinking water under rules being written by the state Department of Natural Resources.

The new groundwater rules are driven by changes in federal regulations and a recent research that shows numerous public wells in the state contaminated by viruses.

While the majority of the state’s municipalities already treat drinking water, the new rules will affect more than 70 communities throughout the state that currently pump untreated water. Among those communities in southern Wisconsin, according to the DNR, are Spring Green, Mineral Point, Hollandale and Dane. Nearly all large cities such as Madison treat drinking water with chlorine or through some other process.

The rules will be presented to the Natural Resources Board sometime this summer, according to Lee Boushon, who heads the DNR’s public drinking water section. Public hearings would be held before the rules are returned to the board for a final vote, Boushon added.

While the rules would affect mostly those communities that would have to install treatment systems, the science behind the change -- the presence of viruses in deep municipal wells and recent studies that show related human health impacts -- has created a new awareness that even drinking water taken from deep underground aquifers is a fragile resource and surprisingly susceptible to contamination.

“We’re finding things we didn’t expect,” Boushon said.

New EPA rules

The findings and resulting emphasis on disinfection are important even to those communities that already treat drinking water, such as Madison where breakdowns in the past have resulted in failures of the chlorination system at some wells.

The groundwater rules are being rewritten to comply with changes in federal groundwater rules from the Environmental Protection Agency, Boushon said. Those federal rules will require stricter monitoring of contaminants such as viruses and bacteria. They would not require disinfection at all water systems.

But Boushon said recent research has shown that even when testing turns up no indicators of possible viral contamination, such as the presence of E. coli bacteria, further tests have still revealed viruses. That uncertainty, he said, has prompted the DNR to propose going beyond the EPA rules and require treatment by all municipal drinking water systems.

“That’s why we’re taking this path,” Boushon said.

Pat O’Flahrity, superintendent of water and sewer for Mineral Point, said the city, about 50 miles southwest of Madison, has considered treatment unnecessary because regular testing has rarely turned up contaminants.

“Why add something to the water when it’s not necessary?” O’Flahrity asked.

Flahrity also said expense is going to be an issue for some of the communities that don’t disinfect drinking water. Most of them are small villages and cities that pay for their water systems by charging customers. Paying for such improvements is difficult in small towns where there are fewer customers to bear the increase.

“It’s going to be expensive when times are tight like this,” said O’Flahrity.

Tom Heikkinen, general manager of the Madison Water Utility, said a smaller water utility should be able to install chlorination equipment for between $5,000 and $10,000. He added that the chemicals cost $400 to $500 a ton. Other costs would include staff time for maintaining and monitoring the equipment.

Treatment recommended

Drinking water experts as well as researchers who have extensively studied viruses in our water supplies say requiring the treatment of municipal drinking water is prudent considering recent findings.

One of the nation’s leading researchers on viruses in drinking water is Mark Borchardt, an infectious disease specialist at Marshfield Clinic in northern Wisconsin. In research conducted in 2005, Borchardt discovered viruses in two of three Madison wells he tested. Then, in a more extensive study conducted by Borchardt and the Wisconsin Geological and Natural History Survey, researchers tested six of the city’s wells every month between September 2007 and September 2008. Viruses, including gastrointestinal and respiratory viruses, were found at least twice in every well, though no well tested positive in every sampling round. Samples were taken from the wells prior to treatment with chlorine, which kills the viruses.

Those findings were a shock even to groundwater experts who had long considered water stored in deep aquifers and shielded by protective layers of shale to be mostly protected from contaminants such as viruses. Until the recent rewrite of federal groundwater laws, communities weren’t even required to test for viruses.

‘Unexpected’ viruses

But Borchardt’s most recent studies were even more revealing of the potential threat. In a study titled “Water and Health Trial for Enteric Risks,” Borchardt conducted studies of the relationship between public health and the presence of viruses in drinking water.

Fourteen Wisconsin communities, not including Madison, participated in the two-year study. Over the two-year period, Borchardt and his team worked with 1,700 participants who completed weekly health diaries. The researchers also analyzed more than 2,000 well water and tap water samples for viruses that cause gastrointestinal illnesses.

Borchardt said the level of virus contamination turned up in the study was “unexpected.” Of 36 wells sampled, 34 were virus-positive on numerous occasions. A few of the wells studied exceeded virus levels found in earlier studies on lakes and rivers.

“Some of the communities,” Borchardt said, “are drinking raw groundwater equivalent in sanitary quality to surface water and utilities that use surface water for their drinking water source are required by federal regulation to disinfect.”

Further, Borchardt said, the studies showed a definite link between the presence of viruses and gastrointestinal diseases in the study populations.

Randy Hunt, a research hydrologist with the U.S. Geological Survey’s Wisconsin Water Science Center, said the threat of viruses is made worse by the sorry state of water and sewer infrastructure in many systems. He said research has shown that a likely source of viruses in the deep wells is broken and leaking sewer pipes.

“What’s the downside?” Hunt said of requiring all communities to disinfect. “Many communities have old infrastructure. So the more barriers you have against viruses the better.”

Tom Stunkard, who regulates drinking water systems in the DNR’s South Central Region, said most of the systems he works with, including Madison, already treat drinking water. For those that don’t, recent research should be an eye-opener.

“I think with what we’re learning about viruses, it’s something that makes sense,” Stunkard said.

Copyright © 2009, The Wisconsin State Journal/Distributed by McClatchy-Tribune Information Services

Tags: natural resources, drinking water, news, state