Viruses from human waste seen in supplies
By Lee Bergquist of the Journal Sentinel
Scores of Wisconsin communities that don’t disinfect their water
supplies would have to install systems to screen out bacteria and
viruses under rules proposed by the state Department of Natural
Resources.
The new regulations are being driven by Wisconsin’s new groundwater
protection law, and by a growing body of research showing viruses from
human waste seep into the ground and contaminate public water
systems.
The Natural Resources Board, meeting in Hayward this week, voted 7-0
to hold public hearings this fall on the new controls.
The Wisconsin Rural Water Association says it supports the changes but
said that members, especially in northwestern Wisconsin, may feel that
the prohibition is unnecessary and a new unfunded mandate on local
government.
In Kewaskum in Washington County, where 4,000 residents drink
municipal water, an official said he expects to hear complaints if
treatment is required.
“I have had members of the community express concern about the fact
that they don’t want to have to taste chlorine in their water,” said
Jerry Gilles, director of public works.
Heavy clay soils have helped Kewaskum filter water before it gets into
the water table, he said. The community tests its water five times a
month.
Milwaukee and the surrounding suburbs would not be affected by the
proposed regulations because they treat their water supplies.
$10,000 per well
The most common method of treatment in municipal systems has been
chlorination. The DNR has estimated that a community might need to
spend about $10,000 per well to install equipment. Communities often
have several wells.
The DNR estimated about 70 municipalities do not routinely disinfect
water.
State law says municipalities need to test water periodically – the
frequency depends on the size of the community and previous testing
results. Also, all communities are required to have backup systems to
treat water if pollutants are found to exceed state limits.
For these reasons, it wasn’t considered necessary to treat water in
communities with good water quality.
But researchers in Wisconsin in recent years have found numerous
instances of bacteria and viral contamination of the water supply.
In the most notable work, researchers led by Mark Borchardt from the
Marshfield Clinic Research Foundation tested water in 14 Wisconsin
communities between 2005 and 2007 and found that 34 of 36 wells tested
positive for viruses.
The viruses can cause gastrointestinal illnesses. Borchardt is not
disclosing how many people were sickened by polluted water until his
findings are published in a scientific journal next year.
In other work, he found the presence of viruses in municipal wells in
Madison in 2005, and then again in more wells in 2007 and 2008 in
conjunction with the Wisconsin Geological and Natural History Survey.
“We were stunned to find viruses in these wells,” Borchardt said.
Bacteria in water can come from various sources, including animal and
human waste that infiltrates groundwater.
In the case of viruses, “we are talking about viruses from human waste
materials,” said Lee Boushon, chief of public drinking water systems
for the DNR.
Viruses pose problem
Viruses present special peril, according to Boushon, because they live
longer in water supplies than bacteria. Also, communities don’t test
for them.
“The thinking was for a long time that if you could find bacteria and
you protected the system from bacteria, you could rely on that as an
indicator of water quality,” Boushon said.
“We are looking to provide additional protection,” he said.
Ken Blomberg, executive director of the rural water association, said
the continuous chlorination of water will become the standard.
He said he expected some pushback – from those who oppose government
mandates and others who are proud of their water quality.
“I do believe that some small communities that have been pumping water
out of the ground and it tastes great will say that it’s a matter of,
‘if it ain’t broke, don’t fix it,’ ” he said.