High-Purity Water from Wastewater…A “Rare” Opportunity

A cooperative water recycling effort between a major U.S. water/wastewater utility and a large oil refinery will provide significant benefits for both parties and will serve as a blueprint for future cooperative efforts between public agencies and industries.The East Bay Municipal Utility District (EBMUD), located in the eastern portion of the San Francisco Bay Area, is implementing the Richmond Advanced Recycled Expansion (RARE) Water Project, in cooperation with the West County Wastewater District (WCWD), to produce high-purity recycled water for use as boiler make-up water at a major oil refinery in EBMUD's service area. The RARE Water Project is an opportunity to address the high-purity water needs of the oil refinery using recycled water if the project can be operational by the end of 2008. The aggressive schedule is driven by other projects being implemented by the oil refinery that have a demand for high-purity water. The oil refinery will gain a redundant, drought-resistant water supply with improved water quality for its boiler make-up water systems. EBMUD will conserve water, reduce dependence on imported water supplies, and optimize a water resource otherwise discharged into the San Francisco Bay.This paper will present the results of a feasibility study which include establishing the demand and supply availability, selection of appropriate treatment processes to meet the high-purity requirements (including on-site pilot testing), development of a recommended project option, and evaluation of alternative construction delivery methods. The feasibility study demonstrates that secondary treated wastewater effluent can successfully be further treated through a microfiltration-reverse osmosis (MF-RO) treatment process to meet the stringent water quality the oil refinery requires for its boilers.