Over the last 30 years, the number of customers in the Alameda County Water District (ACWD) has more than doubled. To meet this rising demand and improve the quality and reliability of year-round water supply, CDM partnered with ACWD to build the first large-scale brackish water desalination facility in Northern California. Through innovative application of emerging water treatment technologies, CDM designed an energy-efficient plant that transformed a previously unusable water source into high-quality drinking water. Tapping into this local water source is also saving the district money by reducing reliance on importing water from a different region.
CDM pilot tested and designed a water treatment plant utilizing an innovative low-pressure reverse osmosis (RO) system that takes advantage of semi-permeable membranes that allow water molecules to pass through, while stopping dissolved minerals that contribute salt and hardness.
The treatment of this water also contributes to an aquifer reclamation program designed to correct saltwater intrusion into the groundwater basin as a result of earlier over-pumping associated with agricultural activities. The plant pumps high-saline water out of the ground so that freshwater can move in to take its place, without unbalancing system hydrology.