AWWA ACE65437

Efficiency, whether defined in terms of capital or operational attributes, can be a critical successfactor to owners in capital project delivery. Alternate delivery methods are often determinant inestablishing the most efficient configuration for water treatment facilities. Such is the case withthe Twin Oaks Valley Water Treatment Plant where San Diego County Water Authority chose toimplement a Design-Build-Operate (DBO) delivery method for its new 100-mgd water treatmentplant. Because of the DBO process, decisions have been made on a true net present value basisdriving many decisions on the project to very high levels of sustainable, efficient, and leastimpact practices including:most cost-effective approach based on use of low-pressure membrane treatment technologycompared to conventional water treatment;zero liquids discharge from the site by neutralizing and recycling backwash streams;reducing consumables over the life of the project, not just during construction;minimized footprints to reduce impact to site and construction material requirements;substantially reduced chemical consumption and residuals handling requirements byeliminating coagulant;minimized environmental impacts with early site work packages to avoid impact towildlife habitat during nesting season;worked win-win agreement with neighboring water district to eliminate 10,000 truck tripsfor fill required onsite; and,designed facilities to maximize use of site topography with campus style facility.As a result, the facility requires less than 11 acres for all elements, including clearwells, of a 100-mgd plant employing state-of-the-art treatment technologies. The plant incorporates lowpressure ultrafiltration (UF) membrane filtration, ozonation/advanced oxidation processes, andbiological activated carbon contactors. The plant utilizes high-rate residuals treatment processesand a unique approach for neutralizing spent chemical cleaning solutions to completely recoverall waste streams generated in the main process stream. This effort, alone, saves over 5 mgd ofpotentially lost water resource and results in a process that is over 99.99 percent water efficient.All aspects of the delivery process - design, build, and operate - have been incorporated intoan integrated approach that has resulted in the highest levels of efficiency and sustainability forthe project with the least impact to the environment and community. Includes table, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2007

Number of Pages:

47

File Size:

1 file , 1.8 MB