A design/build approach to deep aquifer membrane treatment in Southern California

Abstract

Irvine Ranch Water District (IRWD) is located in the heart of Orange County in Southern California. IRWD provides water to and treats wastewater for more than 130,000 people. IRWD is now developing the Deep Aquifer Treatment System (DATS), which consists of an 8 mgd (30,000 cmd) membrane plant for removal of excessive groundwater color and disinfection by-product (DPB) precursors The water has color values over 300 color units, and total organic carbon (TOC) of 18 mg/l. A previous pilot testing program confirmed the treatability of this supply by low-pressure membranes. Because this new supply will be significantly more cost-effective than purchasing additional imported water, IRWD is using the design/build (D/B) delivery method to implement the project as soon as it is practical. The DATS is the first project in California utilizing membrane treatment of deep groundwater with excessive color and organics. The project budget is US $15 million, and the payback period is approximately 6 years, based on comparison with alternative water supply costs. The D/B design package will consist of design drawings and performance specifications in sufficient detail to define key design issues and support the procurement documents and procedures, yet foster opportunities for innovation and consideration of alternative concepts by D/B teams who will competently bid to complete the project.