Chemical in water poses risk of cancer

9/14/2015

Customers of the South County Water System, which distributes Toledo tap water to 30,000 Monroe County residents, were notified by that utility earlier this month that their water earlier this year had an elevated level of cancer-causing trihalomethanes, a symptom of heavy reliance on chlorine and other disinfectants.

But authorities did not then, and still do not see, need for a drinking-water advisory.

According to the U.S. Environmental Protection Agency, trihalomethanes are disinfection by-products that can pose a cancer risk and liver, kidney, and central nervous system problems from long-term exposure.

That’s the key, said Andy McClure, who manages Toledo’s Collins Park Water Treatment Plant. The Collins plant produces the water used by the South County Water System and metro Toledo’s nearly 500,000 customers: There has to be long-term exposure.

Shane Howard, South County’s water superintendent, was not available for comment Friday night but referred to the violation cited by the Michigan Department of Environmental Quality in an Aug. 31 letter to the utility’s customers as well as a notice distributed Sept. 4.

The accompanying notice stated that the average level of trihalomethanes for the past 12 months was 93 parts per billion, higher than the 80 ppb threshold.

The standard was exceeded between May 1 and July 31, according to the notice Mr. Howard signed.

Toledo and other water-treatment plants throughout the country occasionally have issues with trihalomethanes when organic matter and other particles get kicked up into the water column, making water treatment tougher. 

Increasing chlorine and other disinfectants until the problem subsides is a remedy with few alternatives, Mr. McClure said.

Toledo’s plant has no recent Ohio EPA citations for excessive trihalomethanes, nor are they a current problem, Mr. McClure said.

It is not known how much of the problem is attributed to the chronic western Lake Erie algae problem. But Mr. Howard’s letter to South County customers stated the Toledo water’s chlorine levels “have been more elevated than in previous years” because of algae and other problems.

“These higher levels directly affect the formation of disinfection by-products at points in our system,” he wrote.

Most customers need to take no action, according to the notice, but elderly people, parents of infants, and people with severely compromised immune systems should consult with their doctors.

“You do not need to boil your water or take other corrective actions. If a situation arises where the water is no longer safe to drink, you will be notified within 24 hours,” the notice stated.

Greg Stewart, Bedford Township’s supervisor, called the notice “a procedural thing.”

“The bottom line is we get water from Toledo and double-check it,” Mr. Stewart said, stating a problem would occur only through long-term exposure to trihalomethanes. “You don’t want this to keep showing up.”

Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.