East Bay residents to get steady diet of foul water

Lyle Hernandez replaces conductivity probes in a filtration tank at Orinda Water Treatment Plant in Orinda, Calif., on Thursday, May 7, 2015. Lyle Hernandez replaces conductivity probes in a filtration tank at Orinda Water Treatment Plant in Orinda, Calif., on Thursday, May 7, 2015. Photo: Scott Strazzante, The Chronicle Photo: Scott Strazzante, The Chronicle Image 1 of / 23 Caption Close East Bay residents to get steady diet of foul water 1 / 23 Back to Gallery

The acrid tap water that flowed for several days last month into thousands of East Bay homes, prompting a flurry of complaints about its bad taste and smell, will be making an extended comeback starting next week — perhaps through the year, or longer.

California’s drought combined with legal obligations to protect threatened fish species will require the East Bay Municipal Utility District to switch to its unsavory reservoir of water for most of its 1.4 million customers beginning on Sunday. And the water district expects to rely on this supply until at least next winter, when they hope substantial rain and snow will replenish the reservoir.

EBMUD employees call the sour water “the taste of drought.”

Residents in Oakland, Berkeley, Walnut Creek and other East Bay cities can expect the sour taste to return Tuesday, because it takes time for the new water to travel the 90 miles from its Pardee Reservoir source.

Some EBMUD customers first experienced the pungent water in March, after the utility decided to draw from upper valves in the Pardee Reservoir, taking water closer to the surface where it’s warmer and algae tend to bloom. Although the algae are filtered out during treatment, they leave behind compounds that taste sharp but are nonetheless safe to drink.

Usually, EBMUD draws from lower valves deeper in the reservoir where the water is colder and not affected by sunlight and algae. But that colder water must be released into the Mokelumne River so that salmon can spawn, per a 1998 settlement among EBMUD, the U.S. Fish and Wildlife Service and the California Department of Fish and Wildlife. The fish need about 70,000 acre-feet — or 22.8 billion gallons — between now and September, and another 70,000 acre-feet in the next 6 months. (One acre-foot is equivalent to covering a football field in about a foot of water).

With little snowmelt dripping in, EBMUD said humans are stuck with the warmer water that leaves a distinctly bitter aftertaste. The water district is also filling its San Pablo and Upper San Leandro reservoirs with a two-month supply of Sacramento River water, obtained via a federal contract. It’s negotiating with various sellers for an additional two-month reserve from the same river. Because that water comes from a different source and has a different chemistry, it could also have a different taste, EBMUD officials said.

Dissatisfied customers took to social media in March with colorful adjectives to describe the water as “dirty and soapy,” and having the smell of “old/not-quite-rancid bacon grease.”

“Last time we changed the valve on a Thursday, got complaints over the weekend, and reversed the decision Monday morning, wanting to look into other options,” said EBMUD spokeswoman Abby Figueroa. “What I’m saying today is: There are no other options.”

And, she added, the current taste and smell issues could be a lot more widespread than they were in March. Last time, the algae left a sour tang only in areas served by the Walnut Creek, Lafayette, and Orinda water treatment plants, which include Oakland, Piedmont, Alameda, Berkeley, Emeryville, El Cerrito, Albany, Kensington, Lafayette, Walnut Creek, Moraga, Alamo, Danville, Diablo, Blackhawk, San Ramon and Orinda. Those plants, like the others, filter out algae but aren’t equipped to treat the taste left behind from the algae, Figueroa explained.

But this time, areas served by the Sobrante plant (Hercules, Pinole, Richmond San Pablo) and Upper San Leandro plant (Alameda, San Leandro, Hayward and parts of Oakland), might notice a change in their water taste too. Those plants do remove foul tastes, but their equipment is 25 years old and ill-suited to handle larger volumes of water, Figueroa said. She believes that aging infrastructure will be overtaxed by the end of the summer, after treating runoff from two local reservoirs, along with the extra supply being pumped in from the Sacramento River to help the drought-stricken East Bay.

An order by Gov. Jerry Brown last month compounded the problem, Figueroa said, because now EBMUD can’t store any runoff for later in the year. Per the governor’s order, any water coming downstream has to be released so it can help sustain the Mokelumne’s fragile ecosystem.

Currently, EBMUD is expediting design and construction of new treatment systems at its Sobrante and Upper San Leandro plants, projected to cost $20 million. The water district also plans to install an oxygenation system in its San Pablo Reservoir to prevent algae from growing prior to the treatment process. Upper San Leandro reservoir has a similar system already in place.

Such renovations take time, though, and Figueroa said the district can’t do anything fast enough to treat all the algae-tainted water this year.

And according to drought experts, the problem could easily persist into next year as well.

“The last three winters were the driest on record ... and that’s led some people to freak out,” said Michael Hanemann, a professor of environmental economics at UC Berkeley.

He added that while the state enjoyed an unusually wet climate throughout the 20th century, geological records suggest that California has experienced hundred-year droughts in the past.

Moreover, Hanemann added, global warming could mean an even drier future.

“This is different,” he said. “It’s unprecedented that the state is mandating 25 percent reductions.”

EBMUD Director Andy Katz admitted that the district never anticipated water levels going this low, and had to figure out a way to triage when the current drought turned out to be worse than the one California witnessed in the mid-1970s.

He and Figueroa said that sour water could be just one in a slew of problems the state will face as the dry season goes on.

“Dry conditions in the Sierra are a concern for wildfire risks,” Katz said, adding that wildfire in the watershed would have major impacts on water quality.

Figueroa said costs could also rise as water becomes even more scarce.

She predicts other consequences as well, but said we won’t know what they are until they happen.

“It’s never been this bad before,” she said.

Rachel Swan is a San Francisco Chronicle staff writer. E-mail: rswan@sfchronicle.com

Twitter: @rachelswan

Ways to make your water taste better

Chill it.

Install a filter in your refrigerator or sink.

Use a filter pitcher, like a Brita.

Source: EBMUD