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The Yucaipa Valley Water District (YVWD) is currently designing a 12 MGD Water TreatmentFacility. The Yucaipa Valley Regional Water Filtration Facility (YVRWFF) will treat StateProject Water (SPW) that can be augmented by water from the Santa Ana River and the MillCreek. The YVRWFF will provide an additional source of drinking water for the YVWD, whichcurrently relies on groundwater to meet the water demand. Microfiltration has been selected asthe filtration process because it provides a physical barrier that removes particulate matter andbacteria without chemical pretreatment. This paper details the efforts by the District to investigate low rejectionnanofiltration membranes for the removal of DBP precursor material.The Yucaipa Valley Water District currently has approximately 40 wells producing potablewater. The well water is low in total organic carbon (TOC) and YVWD uses free chlorine in the distribution system tomaintain a secondary disinfection residual. SPW contains moderate amounts (3 to 5 mg/L) ofTOC. This is a concern to YVWD, as they will soon be treating surface water with a moderate TOClevel that will form DBPs. Microfiltration is not very effective at reducing TOC and otherspecies that can contribute to DBPs. Therefore, YVWD examined ways to reduce the formation of DBPs of the treated surface water that included: using chloramines versus freechlorine in the distribution system to maintain a secondary disinfection residual; and, using nanofiltration (NF)membranes to treat a portion of the MF filtrate water. An NF system operating on MF treatedwater has the potential to produce water that is both low in hardness and low in DBP formationpotential. This study produced data on various types of commercially available NF membranes toobtain information on their removal properties and assess their applicability to treat State Project Water. Includes tables, figures.

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Edition: Vol. - No. Published: 03/01/2005 Number of Pages: 12File Size: 1 file , 510 KB