H2O Woes: What's the Stink from the Sink?

If you have been noticing an odd smell lately coming from your tap, you are not alone. Zone 7 Water Agency says the odor has been noticed throughout Tri-Valley and Dougherty Valley and is normal for water during warm weather. Livermore residents have been reporting an odor and taste of mildew in the water around town since earlier this week.

Patch reader Liz Hansen posted on the Livermore Patch Facebook: "Is anyone else's water smell or taste like mildew? I thought it was just the house I was visiting but in and outs water tastes the same." Several other readers have noticed a smell and taste of mildew in the water in homes in Springtown area of Livermore.

City of Livermore officials say the water provided to Livermore is safe to drink and may have an odor or taste due to an annual water treatment.

Donna Pontau of the City of Livermore told Patch, via email:

"Zone 7 recently did its annual water treatment to remove algae blooms.  The water is safe to drink, but can temporarily present an odor or odd taste.  It generally lasts for a brief period of time. Both Cal Water and the City purchase their water from Zone 7."

According to the Zone 7 newsletter released a newsletter yesterday, although the water has been treated for the warm weather algae, the odor still lingers. Officials say the water is safe to drink.

The newsletter says Zone 7 Water officials will take steps to prevent the odor during future treatments.

Information provided from Zone 7:

Earthy-Musty Taste and Odor in Drinking Water Not a Safety Concern

Residents in Livermore, Pleasanton, Dublin and Dougherty Valley may have noticed an earthy-musty taste and odor to their water starting in late July. Not to worry. It's a temporary condition caused by warm summer conditions, and does not affect drinking-water safety.

Drinking water 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. The harmless tastes and odors are caused by natural algal blooms that can occur when water is exposed to warmer temperatures and increased sunlight. Zone 7 removes the algae when it treats the water, but the taste and odor may linger.

Zone 7 on July 29 began to further treat its imported surface water supplies with Powdered Activated Carbon, which removes some of the taste- and odor-causing compounds. In addition, Zone 7 is working with the state Department of Water Resources to blend this water with other sources to reduce the amount of algae present.

The taste- and odor-causing compounds do not impact the safety of Valley drinking water, which meets all state and federal regulatory standards and, in almost every category, is of significantly better quality than required.

"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 taste and odor episodes do not affect the safety of drinking water.  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 plans to add ozone treatment in the future to better remove these seasonal tastes and odors.