AWWA MTC69730

AWWA MTC69730 Operation at Yucaipa Valley Regional Water Filtration Facility
Conference Proceeding by American Water Works Association, 11/01/2009

Chlebeck, Jill; Wall, Bob; Cutshall, Wayne; Slater, Harley

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The Yucaipa Valley Regional Water Filtration Facility (YVRWFF), which is a 12 MGD potablewater filtration facility, has been treating surface water since the June 29, 2007. The primaryfeed water source is State Project Water with alternative sources from Mill Creek and the SantaAna River. Water flows from the Crafton Hills Reservoir into the Free Surface Structure.The raw feed water is first fed through two 400 micron automatic back-washable strainers beforereaching the free surface structure. From the free surface structure the feed water flows bygravity through manual basket strainers to the microfiltration system. The basket strainers aresized to remove anything greater than 400 micron that may have accumulated in the free surfacestructure. The strained water is fed directly to the five microfiltration (MF) units to producefiltered water. The microfiltration units operate automatically and adjust to incoming feed flowrates based on the level of the free surface structure and incoming water flow. The filtrationperformance is measured by the turbidity of the filtered water (filtrate). Each unit is equippedwith an individual turbidity analyzer to monitor the filter performance.Seventy-five percent of the MF treated water is further filtered with nanofiltration (NF)membranes to remove organic constituents that can form disinfection byproducts whencombined with chlorine. The NF water is blended with the remaining MF water to make up theplant filtrate water. The plant filtrate is dosed with 3.5 mg/L sodium hypochlorite for primaryand secondary disinfection and 1 ppm corrosion inhibitor to prevent corrosion of the distributionpiping. The facility also has the ability to dose 25% sodium hydroxide for final pH adjustment;however, this has been limited since the plant filtrate pH has ranged from 7.7-8.3 since start-up.Before being delivered to the District, the plant filtrate enters a 6 MG finished reservoir forprimary disinfection contact time. The District has installed 6 MGD of NF based upon thecurrent demand of 8 MGD. The finished product water consists of a blend of approximately 6MGD of NF permeate and 2 MGD of MF filtrate. At this time, the production level of thefacility is such that 8 mgd is the targeted capacity with the 75:25 blending ratio. Includes tables, figures.