Local Water Supplies ( continued )
GROUNDWATER PROGRAM
While San Francisco residents are not currently drinking groundwater , 80 % of Californians depend on it for all or part of their drinking water supply , and have been doing so for generations . The SFPUC plans to blend groundwater with surface water supplies to increase local and regional water supply reliability and to create a more resilient water system . For more information about the Groundwater Program , visit sfwater . org / groundwater .
SAN FRANCISCO GROUNDWATER SUPPLY PROJECT
The San Francisco Groundwater Supply Project is underway in San Francisco and will provide up to 4 mgd of drinking water . The local groundwater supply will supplement water supplies for San Francisco residents and can also be used in emergencies . The SFPUC is building six deep well pumping stations to extract water from the Westside Groundwater Basin , as well as over five miles of pipelines to distribute the groundwater to local reservoirs for blending . Two groundwater wells will also serve as emergency drinking water supplies following an earthquake or other natural disaster , and will include a distribution system to fill emergency water tankers . Construction of the first phase of the project pipelines began in August 2014 and was completed in December 2015 , while construction of the four groundwater wells began in March 2015 and is expected to be complete in April 2017 . Construction of the second phase of the project ( two wells and pipelines ) is expected to begin in early 2017 and coincide with the Westside Recycled Water Project .
The Lake Merced groundwater well under construction .
REGIONAL GROUNDWATER STORAGE AND RECOVERY PROJECT
The Regional Groundwater Storage and Recovery Project is a partnership between the SFPUC and three San Mateo County wholesale customers in San Mateo County : the California Water Service Company ( serving South San Francisco and Colma ), the City of Daly City , and the City of San Bruno . During years of normal or heavy rainfall , the project will provide additional surface water from the Regional Water System to the partner agencies in San Mateo County in order to reduce the amount of groundwater pumped from the South Westside Groundwater Basin . Over time , the reduced pumping will result in a lifetime water savings account of up to 20 billion gallons and will serve as an additional water supply during a drought . Construction started in April 2015 and will be completed in 2018 .
GROUNDWATER MONITORING PROGRAM
The Westside Basin Groundwater Monitoring Program supports groundwater management goals and new groundwater projects by providing information summarizing basin-wide groundwater pumping , groundwater levels and quality in different aquifer systems within the basin , and surface water conditions in Lake Merced . The program also monitors groundwater elevations and water quality to evaluate the potential for saltwater intrusion , determine water quality and groundwater conditions in areas of planned groundwater development , define lake-aquifer interaction , assess general conditions in the Westside Basin resulting from historical and ongoing pumping , and establish baseline groundwater conditions prior to and during implementation of new groundwater projects . Reports summarizing the monitoring results are developed annually . In general , groundwater quality has remained relatively stable for the past decade .
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