RWSA's decision to disinfect water with chloramine raises concern amongst city residents



(File photo) 

The Rivanna Water and Sewer Authority is more than halfway through introducing a new chemical disinfectant to the city’s water supply, but the planned change has sparked anger among some residents who say the new compound isn’t proven safe, and could cause dangerous lead leaching.

Last month, the RWSA announced its decision to replace chlorine with chloramine, a compound of chlorine and ammonia, in the second phase of water treatment in the city. According to RWSA Executive Director Thomas Frederick, the switch was prompted by stricter regulations from the Environmental Protection Agency. The RWSA currently uses chlorine for both the initial disinfectant process and stage-two “backup” water cleansing, meant to keep drinking water pathogen-free as it travels through pipes. But Frederick said chlorine produces too many toxic byproducts to be an acceptable backup disinfectant, and according to the EPA, chloramine is an acceptable substitute.

In a memo to the RWSA Board of Directors, Frederick reported the EPA has written that when proper chlorine to ammonia ratios and appropriate pH balance are maintained, chloramine can be a “practical and effective secondary disinfectant.”

The memo detailed costs of chloramine in comparison to other systems, with the chloramine process being the least costly at $3.3 million in initial costs.

The RWSA does, however, have other secondary disinfection options, including activated carbon filtration systems, currently in use in Scottsville and Crozet. Frederick said the carbon filtration system is more practical on a smaller scale, and would be prohibitively expensive for the city. Also, chloramine systems require constant supervision, which would add another layer of costs to the Scottsville and Crozet plants, because they’re not open 24 hours.

According to Frederick, some facilities under design are about 60 percent complete, and once contractors bid and begin construction, the city can expect the conversion of the secondary disinfection to take place by 2014.

Lorrie Delehanty, a local chemist with 35 years’ experience in scientific research, is concerned about the addition of chloramine to the city’s water for a number of reasons.

“This may be the cheapest way for the city to do it, but it puts a lot of back-end costs on the water customer,” she said.

Delehanty said chlorine is easy to get out of water, with the use of household faucet and shower filters. “That doesn’t work with chloramine,” she said, noting that to filter chloramine out of water is far more expensive and requires an extensive process with an activated charcoal filter.

Charlottesville resident Joanie Freeman said she is concerned about the environmental ramifications, particularly surrounding local gardens and farms. “It could destroy what they’re doing,” she said.

Both supporters and opponents of chloramine recognize the risk that chloramine can leach lead from pipes, potentially poisoning the water. High levels of lead in drinking water can cause severe delays of mental and physical development in children, and can increase blood pressure and lead to kidney failure in adults.

In 2000, the Washington, D.C. Water and Sewer Authority switched to chloramine, and in 2004, the Washington Post reported rising lead levels in drinking water.

The report said chloramines altered the chemistry of the water and “unexpectedly caused lead to leach from lead service pipes” and other plumbing materials like leaded brass solder, and the contamination affected the levels of lead found in water throughout the city. The study found blood lead levels to be particularly high among children who lived in older homes, as pipes from the 1950s and earlier traditionally contain lead.

According to a study conducted by the Virginia Department of Health in 2003, Charlottesville’s 22903 zip code is a “high-risk zip code” in regard to blood lead levels. Zip codes are considered high-risk if 27 percent of the houses within the area were built before 1950, or have a prevalence of children with high blood lead levels.

When questioned about the safety of chloramines with regard to lead, Frederick said there is a significant need for continued education in the community.

“Chloramines have been determined by health experts to be safe at levels that are regulated within drinking water,” he said.

According to Frederick, Washington D.C.’s water is still being disinfected with chloramines now that the city has added the use of corrosion inhibitors.

“When applied properly,” he said, “they help prevent the leaching of lead from metal pipes.” He said the RWSA has tested zinc phosphate as a corrosion inhibitor, and will be adding the chemical to the secondary treatment process.

Opponents fear that while corrosion inhibitors may be effective, failure to monitor and control the treatment process can cause increased corrosion or nitrification.

Several residents, including Delehanty, voiced their concers at the City Council meeting on Monday, April 2. After hearing arguments for and against the switch, Councilor Dave Norris suggested a public meeting be held in order to fully inform everybody of the facts.

“We need to make sure that our community and our councilmen know this side of it,” said Freeman.

A meeting has not yet been scheduled, and Councilor Dede Smith said the public process has “really been compromised.”

“It’s not just a matter of whether they can legally make this decision without public input,” she said. “But in this community, everybody should know better.”