RWSA makes case for adding chloramines to water supply
By Courtney Beale
Wednesday, April 4, 2012
The Rivanna Water & Sewer Authority clarified statistics, fielded questions and sought to calm concerns about the proposed use of chloramines as a water treatment chemical during Monday night’s Charlottesville City Council meeting.
Several area residents and city councilors said they still had questions about the safety of the practice for humans and wildlife.
Chloramines disinfection equipment in Los Angeles, CA
Photo used by permission of LEE & RO, Inc.
Download chloramine documentation
March 9, 2012 memo summarizing basis for chloramines project
July 2011 Executive Summary from consultant Hazen and Sawyer
EPA background information on chloramines
“Any time you’re talking about public health issues, there is a lot of information,” said Thomas L. Frederick Jr. executive director of the RWSA. “Unless you understand the context in which those statistics and data are collected and try to move them into an appropriate context for a local discussion, a lot of what looks like information can become misinformation.”
The RWSA has decided to use chloramines instead of traditional chlorine as a secondary water treatment chemical in order to meet regulations enforced under stage 2 of the Environmental Protection Agency’s disinfectant byproduct rule.
Frederick said that city staff participated in workshops with the RWSA to weigh the pros and cons of treatment options, including chloramines, granular activated carbon filtration, magnetic ion exchange and membrane filtration.
“We are committed to optimization, and optimization does not mean lowest cost,” said Frederick. “It means [which] chemical combination creates the highest quality water that is least reactive to form byproducts.”
City staff and the RWSA ultimately recommended chloramines because the benefits of other methods did not outweigh their costs.
“The capital costs associated with chloramination is $5 million,” Frederick said. He went on to say that granular activated carbon filtration was the next most-affordable option at $18.3 million, and magnetic ion exchange was the most costly with an almost 700 percent price increase over chloramines.
“Of course, none of that matters unless it is safe,” Frederick said.
He stated that both chlorine and chloramines can produce carcinogenic, genotoxic or mutagenic byproducts.
“Chlorine and chloramines produce the same disinfection byproducts across the board,” Stanford said. “But chloramines produce lower concentrations.”
The public remained concerned following the presentation.
Lorrie Delehanty, a Charlottesville resident who works in the medical research field, worried about the possibility of chloramines leaching lead out of pipes as a result of combining with fluoride and improper pH levels.
“Keeping that pH level at exactly 7.4 all the time is not technically feasible,” Delehanty said. “You’re going to get fluctuations.”
The potential of chloramines to leach lead from pipes has been a popular public concern because chloramines were widely publicized as increasing the lead content of the Washington D.C. water supply. Stanford said, however, that D.C.’s spike in lead content was a result of existing conditions in their water.
“D.C. water does not have a problem with chloramines, what they had a problem with was water chemistry,” Stanford said.
He added that Hazen and Sawyer and the RWSA are going to conduct experiments to simulate the water chemistry changes in order to ensure that lead and copper leaching will not be a problem.
Councilor Dede Smith said she was hesitant to use chloramines because of the possible effects they could have on fish populations.
“If I had to make a decision tonight I would say let’s go with carbon filtration,” Smith said. “I still do worry about the fact that it kills fish.”
Joanie Freeman, member of the Healthy Food Coalition, cited a water main break in McLean that resulted in a fish kill. She expressed concerns about the ability of chloramines to persist in water, allowing it to enter waterways.
“Even a minor spill in a local waterway can result in a serious fish kill,” Freeman said. “In Central Virginia trout fishing is a big sport, so if we start killing off our trout we are cutting off an economic factor to our community.”
Stanford countered this, saying only large amounts of water can cause fish kills of the magnitude seen in McLean.
“Chlorine can kill fish just as quickly as chloramines can kill fish,” Stanford said. “Chloramine has a long residual in the distribution system, in very clean water. As soon as it gets out in the environment it is no longer clean water, you have microorganisms, chemicals, particles, these react with [the chloramines] and they dissipate.”
Mayor Satyendra Huja was satisfied with the RWSA’s presentation and explanations.
“I came with the idea that I was going to oppose this proposal, but I am totally convinced by what I heard,” Huja said.
Councilor Kristin Szakos agreed.
“I’m really impressed with the process that you all went through,” said Szakos, “I don’t have any compulsion to change anything.”
Councilor Dave Norris was of a different opinion.
“I’m in the minority here,” said Norris. “My preference would be to hold off on moving forward.”
The council decided to schedule an educational meeting with the RWSA and Hazen and Sawyer in order for the public to be more informed about the chloramination process. The date for that meeting has not been set.