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Chapter 9: Reliability Through Diversification
over-pumping. To overcome those challenges,
two groundwater desalination facilities operate
in San Diego County. Oceanside’s Mission
Basin Groundwater Purification Facility pro-
vides 15 percent of the city’s water supply
using reverse osmosis to treat brackish
groundwater by reducing salt concentrations.
The facility started in 1992 with a capacity of
2 million gallons per day and expanded to its
current capacity of 6.4 mgd in 2002.
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The Sweetwater Authority also has developed
local groundwater supplies. Its Richard A.
Reynolds Groundwater Demineralization
Facility opened in 1999, creating drinking
water from a source considered useless a
few decades earlier.
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Sweetwater – as its
name i
mplies – also draws from deep
freshwater wells.
Some local
water providers have tapped the
U.S. Geological
Survey to map groundwater
supplies in hopes that an integrated assess-
ment will lead to an uptick in pumping.
With
careful
management and the development of
additional capacity, water agencies in San
Diego County could withdraw close to 27,000
acre-feet annually from groundwater basins
by 2020.
DEVELOPING DESALINATI
ON PLANS
With roughly 70 miles of coastline in San Diego
County, removing salts from ocean water
seems like a natural
way to boost drinking water
supplies, especially since reverse osmosis
technology is used successfully to do that
around the world. The Water Authority officially
recognized that potential in 2003, when it
adopted a facilities master plan that identified
seawater desalination as a priority. At the ti
me,
i
mproving membrane technology made large-
scale desalination operations increasingly eco-
nomical, and a local project started to come
together – on paper, at least. By locating a pro-
posed desalination project next to the Encina
Power Station in Carlsbad, developers could
Desalting facility
Rendering of Carlsbad Seawater Desalination Project site
highlighted in white