MCWD Seawater Desalination Facility

MCWD's desalination plant can produce 13% of the District's water when running at full capacity (about 300,000 gallons per day). "Because of the reverse osmosis process used, desalinated water is one of the purest forms of water you can find," states Katherine Oven, senior engineer for Schaaf and Wheeler, MCWD's consulting civil engineering firm for the past 20 years.

With the start-up of the desalination facility, additional water quality parameters have been added to the tests performed by Technical Services Manager Evelina Adlawan and her staff. "For desalination, we are required to conduct a one-year study to determine the influence of ocean water on the seawater intake well," Evelina states. "Samples are collected from the ocean, seawater intake well, and the final product - the drinking water."

Daily testing parameters include turbidity, temperature, total dissolved solids, and pH. Chlorine residual, alkalinity, calcium hardness, and Langlier saturation index (LSI) for the product only are also tested daily. Total and fecal coliform organisms are tested weekly at three sample locations.

In addition, the product water is tested weekly for sulfate, selenium, and chloride. "Since this is a new water source for us, we also have to comply with all the drinking water Title 22 requirements," Evelina adds. "That includes looking at general minerals, general physicals, inorganic/organic chemicals and radioactivity.