Unsavory algae gets into city water Unsavory algae gets into city water (September 10, 2004)

Bad taste, smell, but no risk to public health

By Jon Wiener

A musty taste and smell some Mountain View residents and employees noticed in their water last week was caused by an algae bloom and a leaky valve in the East Bay, according to water officials.

Responding to complaints from local water suppliers, including the city of Mountain View, the San Francisco Public Utilities Commission tracked the source of the complaints to a leaky 76-inch underground valve attached to the algae-filled Calaveras Reservoir, located near Sunol. Commission spokesperson Lillian Brown said the leak has been sealed off until a new valve using water from different sources can take care of the problem.

Algae blooms occur approximately twice a year in open bodies of water, according to Mountain View utility services manager Dave Serge. The algae typically can impact taste and odor but are safe for human health and industrial processes, he added.

Calaveras is particularly susceptible to algae because the SFPUC does not fill it to capacity, said Brown. Every fall, when the water level drops and algae takes over, the commission shuts off flow from the reservoir. She said that the valve might have been leaking earlier than last week, but the hot weather over the weekend of Aug. 28-29 helped drive algae growth and led to complaints from water users.

Some of Serge's co-workers came to work the following Monday complaining about the quality of the water. In addition, at least 15 residents called the city to complain about the water, an unusually high number of complaints from private water users, Serge said.

SFPUC "notified us that there might be some taste and odor but their alert didn't make it seem as drastic as it was," said Serge. An SFPUC memo to the city on Aug. 31 said there might be some taste and odor problems with its water, but that they should be gone within 24 hours.

Mountain View resident Fred Strong said he noticed a difference in water quality on Aug. 30 but did not see an improvement until Sept. 3, or two days after SFPUC had said the problem would be gone.

"I'm not a complainer," said Strong, who called the city on Aug. 29. "I thought it was not a fair way to treat the public, especially when we pay a good amount of bucks for the water and the service."

The Del Valle reservoir, in the Santa Clara Valley Water District (SCVWD), suffered an algae bloom last week as well. The water district used a carbon powder to kill the algae and mitigate the taste and odor problems. Approximately 10 percent of Mountain View users receive water from SCVWD, but not from the Del Valle reservoir.

E-mail Jon Wiener at jwiener@mv-voice.com

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