Willow Glen Resident

News

Residents have not noticed a change in tap water taste

By Monica Heger

Purified by chlorine or purified by ozone--Willow Glen residents so far have not noticed a change in the taste of their water. Last month, the Santa Clara Valley Water District upgraded its water treatment plant to purify the water with ozone instead of chlorine, giving residents cleaner water with promises of a better taste.

"It tastes cleaner," said Mike Di Marco, spokesman for the water district. "I thought that was going to be a lot of hooey, but I really can taste a difference."

Construction of the new treatment plant took about three years and cost $60 million. The upgrade included the construction of an ozone storage area, an ozone generator building, a wash water clarification facility and other support facilities. This is the first major improvement to the drinking water in the area in 40 years. It affects 1.7 million residents in Santa Clara County.

The change in the purification system, however, isn't apparent to everyone.

"We drink tap water and we use a filter, but I haven't noticed any change," said Clark Williams, a North Willow Glen resident.

Williams' neighbors in the North Willow Glen and Palm Haven neighborhoods haven't noticed the difference, either, because they purchase bottled water or have installed filtration systems in their homes.

"It goes to show you this treatment is long overdue," said Ken Eklund.

The North Willow Glen resident said he and his neighbors have shied away from tap water because of its taste.

Ray Yep, the water operations division manager, said even if residents couldn't taste the difference, they could be assured their water is cleaner. He said not only is ozone better at removing material from water, but the new treatment will also reduce the amount of trihalomethane in the water, which has been linked to cancer in some studies and is regulated by the Environmental Protection Agency.

Trihalomethane is a byproduct of chlorine, which was previously used to purify the water. Using ozone reduces the amount of trihalomethane in the water, but the byproduct isn't completely eliminated because chlorine is still used at the end of the treatment, Yep said.

Another benefit of using ozone is that it is more efficient at removing material, such as algae, from the water. Yep said there are often algae bloom in the summer and fall in the San Joaquin Delta, where most of the city's drinking water comes from. He said the algae are difficult to treat with chlorine and often result in a musty smell or taste. Ozone is better at removing the algae.

Ozone, made from liquid oxygen, works to remove algae and other material from water by oxidizing the material.

The district is the largest wholesale water provider in San Jose. The Santa Teresa Plant can treat and deliver up to 100 million gallons per day.

Overall, Yep said treating water with ozone is slightly more expensive, but the result is cleaner, healthier water.