Yee Calls For Hearing On Program That Blends Hetch Hetchy, Local Groundwater

Yee Calls For Hearing On Program That Blends Hetch Hetchy, Local GroundwaterAreas in blue will receive blended water. | VIA SFPUC
Walter Thompson
Published on May 23, 2017

District 7 Supervisor Norman Yee wants the San Francisco Public Utilities Commission to report on the testing and safety standards it's using for a new project that blends local groundwater with water from the Hetch Hetchy reservoir in Yosemite.

For years, San Francisco has received 85 percent of its water from Hetch Hetchy, with the remainder coming from local reservoirs. The San Francisco Groundwater Supply Project launched by SFPUC last month pulls water from the Westside Groundwater Basin to diversify the city's supply.

Groundwater pumping station proposed for Sunset district. | Via SFPUC

According to the agency, the move makes San Francisco less “dependent on distant reservoirs” in the event of drought and emergencies, while providing environmental benefits. The project, which will add pumping stations and infrastructure, is estimated to cost $66 million and be completed in 2019.

By the following year, SFPUC hopes to extract up to 4 million gallons each day from six wells on the city’s west side. The agency estimates that the entire city uses about 60 million gallons of water each day.

Pumped from a depth of about 400 feet, SFPUC is treating groundwater with chlorine before transporting it to the Sutro and Sunset Reservoirs. The mix will be served to more than half the city but would account for no more than 15% of the total supply, which is tested daily.

Although SFPUC announced the groundwater supply project in 2007, “I have heard grave concerns from my constituents about the safety of the drinking water, the testing standards, and the need for the project,” said Yee in a statement.

Sunset at Hetch Hetchy reservoir. | Photo: Justin Gaerlan/Flickr

The new blend meets or exceeds quality and safety standards set by state and federal regulators and does not have a noticeable taste difference, SFPUC claims.

Last December, however, an agency spokesperson confirmed that many residents were drinking "murky, earthy-tasting water" after managers added water from a reservoir in Alameda with high levels of blue-green algae. Yee said some residents are also worried that groundwater has high nitrate levels that could pose a health risk.

Tomorrow's hearing, which is supported by Supervisors Mark Farrell, Ahsha Safai and Jeff Sheehy, will give SFPUC "another opportunity to address the public and hopefully resolve some of the outlying questions that have arisen since the proposal was made," said Yee.

Tomorrow's meeting of the Public & Neighborhood Services Committee will begin at 10:30 in Committee Room 263 in City Hall.