Resolution No. 4793 - Laserfiche WebLink

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7. RECOMMENDED PLAN 7.2.7 Tertiary Filtration Tertiary filtration is reqm.'red for dry weather operations to provide performance reliab~ity and operational flex~l>il/ty to consistently meet the effluent TSS requirements. Filtration is also required for wet season flows to meet the monthly average 85 percent removal requirement for CBOD during peak wet weather flows. Filtration also provides the opporttmity to develop effluent reuse programs. It is recommended that 30 mgd of partial secondary effluent filtration be implemented over the planning period. The current recommended technology is deep bed granular media filters. Table 7.2.1-1 summarizes the proposed 2025 unit process, equipment, and design criteria for tertiary filtration. Expanded facilities include the following items: 8 modular 26 ftx 35 ft deep bed granular media filters Piping gallery Coagulation facilities and chemical room Filter backwash pump station Backwash equalization pumps (located in existing aeration basin) Other filtration technologies that are well suited for smaller filtration appl/cation will be considered to provide filtration for level IV reuse water. 7.3 Recommended Effluent Disposal and Biosolids Improvements 7.3.1 Effluent Disposal Recommendations for reuse ultimately include the development of a lCkmgd Level IV reuse program. The initial reuse demonstration project would include up to I mgd of effluent reuse to a site located near the WPCF. Subsequent reuse projects would be phased in to provide an additional 9.0 mgd of total Level IV reuse. New facilities for the demonstration project include the following: Movable effluent filtration system adequate for 1 mgd of secondary effluent in demonstration project In-line coagulation injection facilities for 1 mgd o Expandable UV system initially adequate for I mgd of Level IV reuse , Pipeline and distribution system adequate for I mgd Upon public acceptance of the reuse facilities, the reuse program can be expanded to 10 mgd of Level IV effluent reuse. Permanent filtration facilities required for dry season permit compliance are necessary prior to expansion of the reuse program. Recommended permanent reuse facilities indude the following: · Tertiary filtration facilit-ies for secondary effluent (required for dry weather permit compliance) · In-line coagulation injection facilities expanded for 10 mgd MWMC_7.0_REV4.DOC 7-7