Pleasanton residents may have noticed an earthy-musty taste and odor in their water starting in late July, according to Zone 7, but not to worry: It's a temporary condition caused by warm summer conditions, and does not affect drinking-water safety.
The same goes for water customers in Dublin, Livermore and the Dougherty Valley in San Ramon.
Zone 7 drinking water, which is imported from the State Water Project and conveyed through the Delta, can occasionally have an earthy-musty taste and odor by the time it reaches the tap, officials explained.
"Taste and odor problems during the warmer summer months are not uncommon for the numerous agencies that receive Delta-conveyed water," said Zone 7 General Manager Jill Duerig.
The harmless tastes and odors are caused by natural algal blooms that can occur when water is exposed to warmer temperatures and increased sunlight, she explained in a press release. Zone 7 removes the algae when it treats the water, but the taste and odor may linger.
On July 29, Zone 7 began to work on the taste by further treating its imported surface water supplies with Powdered Activated Carbon, which removes some of the taste- and odor-causing compounds. The water agency also is working with the state Department of Water Resources to blend this water with other sources to reduce the amount of algae.
But Zone 7 water meets all state and federal regulatory standards and, in almost every category, is of significantly better quality than required, according to the release.
"The taste and odor episodes do not affect the safety of drinking water," Duerig said. "Zone 7 is working hard to remove the taste- and odor-causing compounds and in the meantime wants to assure customers that the water meets all drinking water quality standards."
Zone 7 also has plans to add ozone treatment to better remove these seasonal tastes and odors.
The next Zone 7 Board of Directors meeting is scheduled for 7 p.m., Wednesday, Aug. 21, at the Zone 7 Water Agency, 100 North Canyons Parkway in Livermore.