The Hetch Hetchy water supply is being threatened by the Yosemite fire. Numerous communities in San Francisco depend on the reservoir for their water supply. Officials are concerned that ash from the fire will contaminate the water supply.
The water quality is being monitored closely. The reservoir is tested up to three times per day for contamination,
As reported by ABC News, the community’s water supply is drawn from bottom of the Hetch Hetchy Reservoir. The intakes are close to 300 feet below the water’s surface.
Ashes from the Yosemite fire have fallen into the reservoir. However, they are not expected to sink to the bottom. As long as the deepest water remains clean, the water supply is safe.
Michael Carlin, with the San Francisco Public Utilities Commission, is more concerned about the impact next spring:
“The more problem case… is the spring run off when the ash would come down from the water shed all at once when the snow melts.”
Officials have not reported any current contamination. However, the Hetch Hetchy water is being diverted to reservoirs in San Mateo and Alameda counties.
The alternate reservoirs are closer to the city, and less likely to become contaminated.
As reported by NBC News, the ash is not toxic. However, it would require the water to be filtered. Hetch Hetchy water is not currently filtered, as the reservoir is in a remote location.
If the reservoir becomes contaminated with ash, the water will be filtered at other sites. SFPUC officials say that their treatment plant in Alameda County could handle the extra filtration in an emergency.
SFPUC officials also have the option of purchasing water from other local sources.
Officials and residents in Palo Alto are concerned. Palo Alto gets 100 percent of their water from the reservoir. Debra Katz, with the City of Palo Alto Utilities, is concerned that filtration will “slow down the process of delivering” water to the community.
The SFPUC contends that they are monitoring the Hetch Hetchy water supply. They are in the process of planning for any possible contamination.
[Image via Flickr]