Plant to Mine Water Under Oxnard Plain
A coalition of Ventura County water agencies plans to spend
$50 million during the next five years to build a plant to pump water from beneath the Oxnard Plain, remove its salts and make it safe to drink.
Groundwater Recovery Enhancement and Treatment, which supporters call the GREAT program, recently received $1.6 million in state and federal grants to help cover the $4.5 million needed to design a 20,000-square-foot purification facility.
Along with creating a new source of tap water for 170,000 Oxnard residents, the project would clean up millions of gallons of waste water, which would be used for agricultural irrigation.
“It’s the epitome of reuse or recycling,” said Ken Ortega, Oxnard’s water superintendent. “The benefits outweigh the costs.”
Planned for completion by 2007, the program would help local water agencies reduce their dependence on expensive water carried by aqueduct from Northern California. Imported water that Oxnard buys from the Calleguas Municipal Water District in Thousand Oaks costs about five times as much as the water it pumps locally, Ortega said.
Oxnard spends about $600,000 a year to collect water from its own wells, and buys $1.6 million worth of water from the Santa Paula-based United Water Conservation District, which mostly serves agricultural customers. The city spends an additional $9 million annually to purchase water from the Calleguas district.
“Obviously we’re interested in saving money, but we’re also interested in stabilizing our rates,” Ortega said.
The west county’s four water agencies--Oxnard, Calleguas, United Water and the Port Hueneme Water Agency--support the Groundwater Recovery Enhancement and Treatment project.
Since 1996, the Port Hueneme Water Agency has operated a test facility to treat salty water. After studying three methods of removing salts and other impurities, project officials opted to employ a process known as reverse osmosis in the new filtration plant that would pump ground water and squeeze it through plastic membranes with microscopic holes. Those openings are just large enough to allow water molecules to pass through, but small enough to block salts and other particulates.
“All of the nasties are on the other side of the membrane, and are backwashed out of the system,” Ortega said.
The remaining briny water, which is still less salty than ocean water, would be discharged into the Pacific or used to restore coastal wetlands in the Ormond Beach area.
Oxnard now discharges about 25 million gallons of treated, salty waste water into the ocean daily. Under the new project, the city’s waste water treatment plant would give this discharged water an additional filtering before sending it on to the Port Hueneme facility for desalination. Once free of salt, the water would then be used on crops.
During rainy months, when farmers rely more on the weather for irrigation, the treated waste water would be pumped into the ground on the Oxnard Plain to create an underground barrier to prevent sea water from leaching into the system.
The Port Hueneme Water Agency, with 50,000 customers, supports the project in concept but has not yet committed to the full plan, said Douglas Breeze, the city’s public works director.
Breeze also said the program could benefit the 220,000 water customers in Oxnard and Port Hueneme by potentially lowering their water bills.
Water agencies are always looking to enhance water quality and increase local reserves, said Donald Kendall, general manager of Calleguas, which provides water from the Sierra Nevada range in Northern California to more than 500,000 customers from Oxnard to Simi Valley.
Kendall said there is a reason why Calleguas in the east county would support an expensive project in Oxnard: When local water agencies buy less water from Northern California, the overall costs go down.
Once Oxnard produces more of its own drinking water, that would free up water for customers elsewhere. Although Calleguas would lose some of Oxnard’s business, it would have additional water available to sell to other customers.
For more information about the Groundwater Recovery Enhancement and Treatment project and other Oxnard water programs, log on to https://https://www.oxnardwater.org