Water Additive Can Harm Dialysis Users

Officials have resumed adding a disinfectant to some Ventura County water that is considered dangerous to patients on dialysis machines and to tropical fish, a spokesman for the Metropolitan Water District of Southern California said Tuesday.

The district, which stopped using the anti-algae agent chloramine more than five months ago, began using it again Monday to stem the growth of harmful bacteria in water brought in from Northern California, said Edward Means, MWD’s director of water quality.

Chloramine, a mixture of chlorine and ammonia, was introduced to water supplies five years ago. Beginning in March, however, the district stopped including ammonia in the disinfectant mixture and used only chlorine because it temporarily purchased water from suppliers along the Colorado River. That water has a high mineral content that negates the need for a strong disinfectant, Means said.

But this week the district returned to treated state water, and it will begin to distribute it to districts throughout the Southland, Means said.

“We sent out letters warning all hospitals and those persons that may be affected by it,” Means said. The chloramine is added at a concentration of about 2 milligrams per liter.

In Ventura County, about 450,000 residents and 500 farmers from Camarillo to Simi Valley depend on MWD for all or part of their water.

Chloramine affects dialysis patients by preventing the flow of oxygen to the bloodstream when it comes in contact with blood being filtered through dialysis machines, which use water. It also impedes oxygen absorption in fish when it comes in contact with their gills. The ammonia, which can be filtered out with granulated carbon devices, poses no risk to humans, including dialysis patients, who drink it, officials said.

Saltwater and freshwater tropical fish would be at risk if tap water is added to tanks without a special ammonia-absorbing agent.

“It takes all the slime off their skin and the ammonia burns them,” Ventura pet store manager Judy Mart said. “Most of them end up dying.”