The issue of whether to add chloramines to the Charlottesville-Albemarle urban water supply has garnered interest from several advocacy groups around the country.

Their lobbying has bolstered the arguments of local residents who oppose this method for disinfecting public drinking water. The end result has been a stream of feedback to local government that includes questions about public health, the promotion of alternatives, and an online petition signed by more than 1,000 people.

Chloramines are created by combining chlorine and ammonia and are intended to prevent pathogens from growing within the water distribution system. The Rivanna Water & Sewer Authority says a new treatment approach is necessary to meet standards set by the Environmental Protection Agency.

In response to public concern, Charlottesville City Councilor Kathy Galvin, Supervisors Kenneth C. Boyd and Duane E. Snow and the RWSA’s executive director, Thomas L. Frederick Jr., met with EPA officials last week to better understand the changing regulations and to hear the EPA’s stance on the two water treatment options being considered by the RWSA — chloramines and granular-activated carbon (GAC).

“EPA supported both chloramine and GAC,” Frederick said. “We asked if the EPA was backing away from chloramine and they firmly said no, they are not backing away and consider chloramines to be very safe.”

Hazen and Sawyer, the RWSA’s consultant for the project, estimated GAC would cost about $18.3 million. They gave chloramines a $5 million price tag. Despite its higher costs, many community members have called for carbon filtration to be installed instead of using chloramines.

Although the use of chloramines serves to reduce the amount of carcinogenic byproducts in drinking water, opponents say it creates its own variety of byproducts, some of which are also carcinogenic.

William Mitch, a professor at Yale University and a nitrosamine specialist, said carcinogens are most commonly formed in drinking water when the source water being treated contains polymers or wastewater contaminants from upstream, neither of which is expected to be an issue here.

“Unfortunately, recent research indicates that chloramines are associated with the production of nitrosamines,” Mitch said. “These byproducts are roughly 10,000 times more potent carcinogens than regulated [byproducts associated with chlorine], but also form at roughly 10,000 times lower concentrations during drinking water treatment.”

Mitch added that nitrosamines are present in much higher quantities in commonly consumed foods such as beer and sausages. He said one of the goals of EPA regulations is to “target maintaining lifetime cancer risks at 1 in 1 million to 1 in 100,000.”

“If your utility is maintaining a reasonable concentration, i.e. within regulations, they are targeting the lifetime cancer risks, and [thus] the rates associated with drinking water are low,” Mitch said. “You’re going to have a lot higher risk from eating various carcinogens in food.”

According to Frederick, EPA representatives said that they had recently conducted their own studies on the long-term carcinogenic effects of drinking chloraminated water and they were finding some interesting conclusions.

“They told us from their recent studies that even though cancer rates are very low with both free chlorine and chloramines, they are finding that chloramine risks are lower, not higher, compared to free chlorine,” Frederick said.

Mitch said disinfecting any drinking water is essentially a balancing act.

“It’s sort of an optimization game, balancing acute risk of getting sick from pathogens versus a chronic risk associated with cancer,” Mitch said. “I think, overall, the primary goal [of drinking water disinfection] is still pathogens and if you’re going to disinfect the water, you’re going to have some byproducts.”

Supporters point out that chloramines are used by 70 percent of Virginians. Blacksburg and Richmond, which both use chloramines, have had no major complaints concerning the chemical. Despite that, opponents claim the lack of research done on the health effects of chloramines is disconcerting.

Mitch explained that the lack of studies is due to a few factors. He said many byproducts were discovered fairly recently and the nature of studying drinking water makes research complicated. He said people are rarely only exposed to one drinking water source and it is hard to account for other exposures to carcinogens.

“It’s possible to do these epidemiological studies but it’s very difficult because it’s very hard to accurately quantify exposure over 70-year lifetimes,” Mitch said.

Peter de Fur, an environmental consultant and part-time professor in the Center for Environmental Studies at Virginia Commonwealth University, drinks chloraminated water at his office and said he was not concerned about its presence.

“There are going to be unknowns, but I don’t think it rises to the same level of concern like other issues that people have raised in the water supply such as fluoridation and arsenic,” de Fur said. “Because the scientists have been paying a lot of attention to this … what tends to happen, especially with drinking water, is that the regulatory agencies are more vigilant to ensure concentrations [of byproducts] don’t rise and that there is new toxicology information which is applied.”

De Fur said he understands why many consider carbon filtration to be a superior option.

“When we have an approach that doesn’t involve adding chemicals, like granular-activated carbon, there is not only a certain logic but also, I think, a non-chemical method that removes without addition has greater merit than adding chemicals,” de Fur said. “We do have experience in the U.S. of learning about chemicals that have not been the best choice and then we follow different approaches.”

A public hearing on water treatment options will be held Wednesday by the “four boards” responsible for the local water supply — the RWSA, the Albemarle County Service Authority, Charlottesville’s City Council and Albemarle’s Board of Supervisors. The meeting will be held in Lane Auditorium at the County Office Building-McIntire starting at 7 p.m.