Arsenic pollutes Iowa’s water supplies

Originally printed in the Des Moines Register

Hundreds of Iowans across the state are drinking tap water polluted with poisonous arsenic as health workers move to rein in the problem.

The problem is so widespread that health officials statewide gathered last week in Des Moines to discuss remedies. Large public water supplies routinely test for arsenic. But health officials are now stepping up efforts to encourage private well owners to pay for their own tests, which cost about $20.

The element occurs naturally in Iowa’s soil. It leaches into ground water, which is the source of tap water for 55 percent of Iowans.

Drinking large amounts of arsenic over decades could lead to cancer of the skin, bladder, lungs, liver and prostate, as well as cardiovascular and respiratory problems. Short-term exposure to very high levels can cause nausea, vomiting, diarrhea and skin problems, according to the U.S. Environmental Protection Agency.

Five public water systems currently violate arsenic standards, and 15 others have had violations over the past decade, Iowa Department of Natural Resources records show. The five now in violation are the towns of Lanesboro, Mallard and Scranton, and two rural subdivisions, Gallery Acres West near Solon and South Park near Iowa Falls.

“All of them have arsenic problems,” said Diane Moles of the DNR water-supply staff. “They need to either put in treatment or be able to blend them down” by mixing in clean water from other uncontaminated sources.

In addition, a recent University of Iowa study found that nearly half of the 475 private wells checked between 2006 and 2008 tested positive for arsenic, with 8 percent over the limit for drinking water.

Cerro Gordo County health officials have been tracking arsenic for more than a decade, and currently are testing rural wells as part of a federally funded program.

Arsenic accounted for about 3 percent of drinking-water standard violations last year among the state’s 1,900 public systems, the DNR reported. Total coliform bacteria topped the list, accounting for nearly 60 percent of the violations. Nitrates resulted in about 8 percent.

Water quality rules require 1,400 of Iowa’s systems to check for arsenic. In addition to municipal water supplies, some small systems serve rural subdivisions or businesses such as truck stops.

Moles said most water plants quickly fix the problem by using a handful of tested solutions. One method is to treat the water to remove iron, which also removes arsenic. Or the system can dilute tap water with clean supplies from another source. Some drill new wells, or hook up to another arsenic-free water system.

For one system near Solon, though, none of those solutions is available. So 41 customers of the Gallery Acres West system in Johnson County continue to drink water with too much arsenic. The water isn’t being treated, in part because there is no sewer to carry the wastes that would result from the process.

Gallery West has recorded 22 arsenic violations in the past decade. Officials there could not be reached for comment.

“We are already in the process of looking into new treatment options to rectify this situation as soon as possible,” city officials wrote in a letter to the more than 500 residents.

Some of the five systems in violation of arsenic standards learned only recently of the high readings, Moles said. All but the Solon-area system have found a way to treat the problem.

Scranton and Mallard recorded readings in recent months that were eight to nine times the limit.

Scranton’s violation in July marked the first time in a decade the town exceeded the standard.

Lanesboro is treating for iron, in turn reducing arsenic. The town has had only one violation in the past decade.

Mallard, population 280, had three violations in that period, all recent. The town is changing its water treatment, Moles said. “They are getting it under control, but it’s going to take a little while,” she said.

Mallard residents have complained more about the taste of the chlorine, which at first was added to the water at a higher rate, said City Clerk Becky Larson. When that didn’t work, the water plant cut back on chlorine, which seemed to help. Workers also changed filters, Larson said.

“We don’t know if we’ve come up with the absolute answer,” said Larson. “We are working closely with DNR.”

No one has complained about the health risk, said Larson. “After we cut back on the chlorine, I haven’t heard a thing from anyone for probably four months,” she said.

South Park had one violation in the past decade, and routinely has readings close to the limit, Moles said.

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