Use of a Water Disinfectant Is Challenged

After an unusual petition drive, city officials in Hannibal, Mo., decided last week to put the question of how the city disinfects its drinking water in the hands of voters.

Best-known as the boyhood home of Mark Twain, the Mississippi River city of 17,000 people has become the latest battleground over chloramine. The disinfectant, a combination of chlorine and ammonia, has been widely adopted by water utilities in recent years after the federal government tightened regulations on some hazardous byproducts that result from using chlorine alone.

Residents in Stockton, Calif., and Tulsa, Okla., have opposed the use of chloramine, partly because they say it causes rashes and respiratory problems in sensitive individuals.

“It smells like you’re drinking bleach,” said Melissa Cogdal, a 45-year-old customer-service representative for a jewelry company who helped lead a campaign to get Hannibal to ban chloramine, which the city began using in September. “It’s a concern for a lot of us that live here.”

But Bob Stevenson, general manager of the Hannibal Board of Public Works, opposes the move, because chloramine has helped the city comply with federal and state regulations for byproducts in drinking water. “In our view, chloramines are like a miracle cure,” he said. “They got us out of a tough problem pretty cheap.”

Last week, rather than adopt a proposed ordinance, the Hannibal City Council chose to let voters decide in coming months through a referendum.

Chloramine has been used to treat drinking water for decades. Its use skyrocketed after the federal Environmental Protection Agency placed stricter limits in 1998 and 2006 on 11 disinfection byproducts. Most, such as chloroform, are created when chlorine interacts with naturally occurring organic material in rivers and other water sources, and some are considered probable human carcinogens.

But many experts now say chloramine is creating problems of its own. Researchers have identified hundreds of disinfection byproducts in drinking water, including some that increase in the presence of chloramine and can be more toxic than those regulated by the EPA. Based on data from 11 cities, a 240-page study published in April by the Water Research Foundation, a Denver nonprofit that gets funding from the utility industry, concluded that utilities looking to reduce levels of such disinfection byproducts should avoid chloramine, among other options.

“We’re questioning the wisdom of using chloramines as much as we do in this country,” said David Reckhow, a University of Massachusetts professor of civil and environmental engineering and lead author of the study. At the same time, he said research into the link between chloramine in drinking water and symptoms such as rashes is inconclusive.

The latest research raises questions about the effectiveness of the EPA’s regulations. An agency spokeswoman said the EPA plans to publish a decision by year-end on whether it will revise the rules.

The issue highlights the tricky balancing act carried out by public utilities that can lead to problems like the crisis in Flint, Mich. The city switched its drinking-water supply to the Flint River in 2014 and failed to add phosphate to make the water less corrosive, causing lead to leach from pipes into people’s homes. Flint didn’t added chloramine to its water system before its lead problems, and it hasn’t since, according to water experts.

For many utilities, using chloramine has been the most affordable way to cut the presence of regulated disinfection byproducts. But chloramine can make water more corrosive. Its use was blamed for lead contamination in Washington, D.C., in the early 2000s.

Poughkeepsie, N.Y., stopped using chloramine in 2010 after its water routinely ate through rubber gaskets in homes, turned water the color of tea and led some people to complain of rashes and breathing problems, said Randy Alstadt, the city’s water plant administrator. The utility, which serves 80,000 people, expects to have online in September a $12 million system that uses ozone and activated carbon to remove organic material from the water, which comes from the Hudson River. It will then reduce the amount of chlorine it uses.

By comparison, using chloramine had cost Poughkeepsie about $25,000 a year for the chemical and a storage tank, among other things, according to Mr. Alstadt. “It’s a low-cost alternative, but I don’t think it’s the right thing,” he said.

In Hannibal, which gets its drinking water from the Mississippi River, the Board of Public Works started using chloramine last fall after consistently exceeding EPA limits on regulated disinfectant byproducts between December 2011 and August 2015. One problem, according to Mr. Stevenson, is that water sits longer in less used parts of the system, allowing more byproducts to form.

Mr. Stevenson, the board’s head, said adopting an alternative to chloramine will cost the city millions of dollars it doesn’t have and likely take years for the permitting and construction of new facilities and filtration systems. If the city reverts to chlorine in the meantime, it will face fines for high levels of disinfection byproducts again. “This is our quandary,” he said.

Steve Via, director of federal relations at the American Water Works Association, which represents 4,500 water utilities, said chloramine should remain “a tool in the toolbox” for utilities.

He said recent research has raised concerns about unregulated chemicals created by chloramine, but the industry has a good track record of reducing regulated disinfection byproducts. “As a sector, we’re still trying to find out what’s the best solution,” he said.