With the growing imbalance between water supply and demand and an estimate that residents in San Mateo County will need an additional 5 million gallons of water a day by 2018, more cities are looking toward using recycled water to reduce the need for fresh Hetch Hetchy water.
In March, the San Mateo County Civil Grand Jury released a report “Water Recycling — An Important Component of Wise Water Management” that encouraged the two cities in the county that currently recycle water, Daly City and Redwood City, to expand their programs while encouraging other cities, such as San Mateo and Foster City, to continue their efforts in establishing such programs. Most cities in the county, however, do not have any efforts in place to take up water recycling, according to the civil grand jury.
Some cities are starting to respond to the civil grand jury on its water report as mandated by state law and this past Monday night, the San Mateo City Council gave staff direction to continue pursuing its recycled water efforts.
Currently, San Mateo and the Estero Municipal Improvement District, which serves Foster City, are creating a Wastewater Treatment Plant Master Plan that explores the feasibility of producing recycled water.
The county and its cities must diversify their water supply sources and reduce their residents’ dependence on water from the Hetch Hetchy regional water system, according to the civil grand jury report.
Recycled water is sewage treated to remove solids and certain other impurities, such as metals and ammonia, so the water can be used in landscape irrigation and industrial processes, or to recharge groundwater aquifers, according to the civil grand jury report.
In 2007, the city of San Mateo adopted its Sustainable Initiatives Plan which called for a market survey on developing a recycled water system since the supply is expected to decrease and the cost is expected to triple, according to a Public Works Department report.
The market survey indicated the potential recycled water user types within the city are primarily landscape irrigation at parks, golf courses, high-density residential buildings, highway medians, schools and industrial or commercial cooling systems with a cooling tower.
Potential users in San Mateo would have a demand for 6.2 million gallons of recycled water a day and the city’s Wastewater Treatment Plant treats a daily flow of 12 million gallons a day, according to the market survey.
“If properly treated, there would be an ample recycled water supply to meet the potential recycled water user’s needs,” according to the market survey.
Constructing the pipelines and pump stations in San Mateo, however, would cost at least $25.4 million in capital costs and about $340,000 a year after to maintain the system.
City staff have reached out to the California Water Service Company, which provides water for San Mateo residents, to see if it would be interested in a potential partnership to develop a recycled water program and may assist in the construction, operation and maintenance of the distribution system, according to the market survey.
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