First Person: OC’s First Desalination Plant
By William Hunt, OCWD Director of Special Projects
The Orange County Water District has a long traditionof innovation in its approach to water supply and groundwater management. Back in 1977, I joined OCWD as an operator of its brand new, state-of-the-art Water Factory 21 (WF21)—an advanced recycled water treatment plant. At the time of my arrival, a newly built (3 million gallon per day) seawater desalination plant was present on our site to provide a source of low salinity water needed to operate WF21.
The seawater plant was built and fully commissioned, but never placed into regular service. The reason it did not operate after commissioning was its bad timing relative to the 1970s energy crisis (1973-1979). Boiling millions of gallons of water per day with natural gas during a time of rising energy costs and constrained supply was both energy intensive and costly. Because of the energy supply constraints it was no longer feasible to operate the desalination plant for its intended use.
Without ultra-pure ocean desalinated water, we could not sustainably operate Water Factory 21 because the reclaimed wastewater was too salty to put in the ground without first diluting it. The initial response to the loss of the desalination water was the drilling and use of low salinity deep-wells as a temporary source of dilutent water. The long-term solution was building the world’s largest 5 million gallon per day reverse osmosis (RO) plant as an alternative source of fresh water. Water Factory 21 was the first plant to use RO on wastewater at that scale. The rest is history.
Willian Hunt worked for OCWD from 1977-1982 and returned 27 years later in 2009 as the Executive Director of Operations, before his current position as Director of Special Projects.