Department of Water Switches to New Disinfectant

Tastier, better-smelling water is on the way for the Sunland-Tujunga area.

Beginning this week, the Los Angeles Department of Water and Power will launch a $4 million program to use the disinfectant chloramine to kill potentially harmful bacteria in the city’s water supply.

Chloramine, a mixture of chlorine and ammonia, does not have the strong taste and smell of chlorine, which the DWP currently uses. Nor does it rapidly form same amount of disinfectant by-products that chlorine does, said Pankaj Parekh, director of water quality compliance for the DWP.

“Even though both of them protect it [the water], chlorine has the taste and odor problem that goes with it,” Parekh said.

Chlorine, more powerful than chloramine, reacts more quickly than chloramine with natural organics in the water, forming unwanted disinfection by-products such as trihalomethanes, a carcinogen. DWP imports water acquired from natural sources, which increases the likelihood of natural organic substances in the water, Parekh said.

“We want to reduce the by-products,” Parekh said.

The DWP has alerted residents to the change, especially those sensitive to chemicals in water. Dialysis patients and owners of fish-both freshwater and saltwater-should make sure they use a product that removes chloramine from water, Parekh said. Activated-carbon water filtration systems remove chloramine, but users are advised to check with the manufacturer for specifics.

Chloramine is an Environmental Protection Agency-approved drinking water disinfectant, and the Metropolitan Water District, the state’s largest water wholesaler, has been selling chloraminated water for years.

The Harbor and East Los Angeles areas were the first to receive chloraminated water from DWP. But the Sunland-Tujunga area and other parts of the city did not as modifications were made to DWP reservoirs. The DWP plans to convert the entire city to chloraminated water in the next five years, Parekh said.

“We are sort of behind because we have had these large open reservoirs that we needed to cover or bypass,” Parekh said.

In an open reservoir exposed to sunlight, chloramine can attract algae growth, the water quality compliance director said.

The Green Verdugo Reservoir serves the Sunland-Tujunga area is a covered reservoir, and the DWP will add a permanent ammonia system that will add that chemical to the chlorinated water, Parekh said.