Resolution No. 4793 - Laserfiche WebLink

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UV system expanded for 10 mgd of Level IV reuse - Pipelines to additional reuse sites up to 10 mgd Reuse pump station and distribution system expanded to 10 mgd Additional reuse projects include the application of 1.25 mgd of Level II reuse effluent to the SIWF and 1.5 mgd of Level II reuse effluent at the Biocycle Farm. The Biocycle Farm would require an irrigation pipeline and microspray distribution system. Table 7.3.1-1 (located at the end of this chapter) summarizes the existing and proposed 2025 unit process, equipment, and design criteria. 7.3.2 Biosolids Stabilization Temperature-phased anaerobic digestion is currently recommended to provide for future solids stabilization needs at the WPCF. Conversion to a two-phased digestion process will delay or eliminate the need to construct a fifth lagoon and would provide for Class A biosolids stabilization. Recommended new facilities include the following: Digester mixing improvements for existing three digesters Construct fourth conventional mesophilic digester - Construct thermophilic digesters to provide Class A biosolids Pre-pasteurization processes may also be considered for future solids stabilization to provide Class A biosolids. However, the current recommended plan is based on two-phase anaerobic digestion. Table 7.3.2-1 (located at the end of this chapter) sttmmarizes the existing and proposed 2025 unit processes, equipment, and design criteria. 7.3.3 Facuitative Sludge Lagoons At this time the need to construct a fi£th lagoon by a specific year is not recommended, nor is it expected that a fifth lagoon will be needed within the design period. Overall plant VSS reduction requirements are likely to be achieved even if VSS loading to the existing lagoons exceeds design criteria due to proposed digestion system modifications. It is recommended that lagoon VSS loading rates be closely monitored as upstream process improvements and additions are implemented. Digester mixing improvements will increase the active volume of the existing digesters, the addition of a fourth digester will provide additional digester volume, and the potential use of an advanced digestion process will all contribute to improved reduction in VSS loads to the lagoons. It is recommended that the existing lagoons be relined in accordance with previous planning activities that are not part of this facilities plan. Table 7.3.2-1 summarizes the existing and proposed 2025 unit processes, equipment, and design criteria. 7.3.4 Biocycle Farm Land Application The Biocycle Farm is a valuable asset to MWMC's biosolids application program. The current operation as a non-irrigated land application site provides enough capacity to reduce and maintain solids inventory in the FSLs throughout the design period. Therefore, it is recommended that the site continue to operate in its current mode. The majority of the costs associated with continued operation of the site have already been absorbed in the purchase of the land, installation of the distribution pipeline, construction of the Biocycle 7-8 MWMC_70_REV4 DOC