In order to meet EPA water safety guidelines, North Haven recently constructed an ultra-modern water treatment plant that cost the island’s ratepayers $2.2 million. But shortly afterwards, the EPA tightened regulations to lower the allowable level of disinfection byproducts in drinking water. North Haven’s water didn’t pass the new standards.

“It was kind of frustrating,” said Glen Marquis, North Haven’s water district superintendent.

Marquis had company. The new regulations sent water utilities and municipalities scrambling for ways cut chlorine use to lower byproduct levels. Disinfection byproducts are chemical compounds created when chlorine mixes with organic materials in water; scientists worry these byproducts are possible carcinogens.

Like many others, North Haven water officials elected to solve the problem by adding chloramine, a mixture of chlorine and ammonia, to their water. Not only did byproduct levels drop well below EPA’s safety limits because of the decreased chlorine use, Marquis said, but customers found the water tasted better.

“I’ve been passing it off as the golden treatment,” he said.

But that treatment might come with a price. A small but vocal group of activists throughout the country argue that chloramine-treated drinking water is responsible for a host of medical woes, including asthma, intestinal bleeding and rashes. Some water treatment experts have found that chloramine use has resulted in increased lead levels in some water systems and the creation of even more toxic disinfection byproducts.

Chloramine use is not new, but its use as a primary disinfectant has been on the rise. Water municipalities find it the cheapest and quickest way to lower their byproduct count and meet EPA requirements.

It’s estimated that one-third of all U.S municipal water systems use chloramine. Maine state health statistics show 13 Maine water districts currently use chloramine; officials say that number is expected to rise. On the coast, the list includes Bath, Boothbay Harbor, Kennebunk, Kennebunkport, North Haven, Portland and Wells. Damariscotta’s Great Salt Bay Sanitary District is expected to chloraminate soon.

While some municipalities, like Portland, have been using chloramine for decades, many others have just begun to treat with it. As more municipalities switch over, complaints nationwide about medical ailments from exposure to chloramine-treated water have increased.

But avoiding the water is difficult and expensive. Unlike chlorine, chloramine can’t be boiled off and doesn’t dissipate, and the only way to block it is to install a filtration system that may cost more than a hundred thousand dollars to install and several thousand dollars a year to maintain, according to Denise Johnson-Kula, president of a group calling itself Citizens Concerned Against Chloramine.

Medical studies on chloramine exposure won’t be undertaken until more chloramine-sensitivity reactions are reported by doctors, Johnson-Kula said, but many doctors won’t believe patients who complain of chloramine side-effects. To complicate matters, she said, most people suffering from chloramine reactions might not realize they are getting sick from the water.

Some scientists and water experts are beginning to question chloramine use. Dr. Mark Edwards, a civil engineering professor and expert on water piping at Virginia Tech, has found that complaints from water-system clients serve as a sort of canary in the coal mine, providing the first indication that something is wrong.

“You ignore these [complaints] at your own peril,” Edwards said.

In Washington, D.C., he and other researchers discovered that chlorine had an unknown benefit of keeping years of built-up lead particles on water pipes, even in supposedly “non-lead” piping like brass. Once the city switched to chloramine, however, lead flushed from the pipes and ended up in the water supply. The resulting lead levels were more than 3800 times higher than the legal U.S. safety limit.

So far, Edwards said, lead level problems from chloramine use have been rare.

Ironically, the EPA byproducts guidelines that started the push toward chloramination might be creating a new kind of byproduct problem.

Dr. Michael J. Plewa, a genetic toxicologist at the University of Illinois Urbana-Champagne, said there’s still so much unknown about chlorine, let alone chloramine.

“We really are ignorant of the toxicology,” Plewa said.

But when switching to chloramine, the percentage of identified byproducts shoots down to the teens. “You increase the level of ignorance,” Plewa said. “The federal agencies have dropped the ball on funding this kind of work,” Plewa said.

Both Edwards and Plewa emphasized that widespread water disinfectant is one of the greatest scientific and engineering feats in human history, resulting in a marked lifespan increase. But both worry the EPA has created more problems than it’s solved by regulating chlorine-created byproducts.

Repeated requests for an interview with EPA officials for this story went unanswered.

Carlton Gardner, compliance and enforcement team leader of the Maine State Drinking Water Program, said the state has no choice but to follow EPA rules. If the EPA allows chloramine as a water disinfectant, the state will continue to, as well.

“We look at it as one of the tools in the toolbox,” Gardner said.