ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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Transportation and Circulation The Increased Land Disposal Alternative would result in construction of similar facilities at the WQCF and construction of additional pipelines to convey effluent to new land disposal areas. This alternative would result in slightly greater construction-related transportation impacts because a greater number of roadways would be disturbed and a greater number of construction personnel would be required to construct the pipelines. While it is likely that construction-related transportation impacts would be less than significant,nonetheless, overall impacts would be slightly greater than the project.[Greater] Cultural Resources The Increased Land Disposal Alternative would require the construction of wastewater treatment and effluent conveyance pipelines,potentially resulting in impacts related to the disturbance, destruction, and physical or visual alteration of any previously undiscovered/unrecorded cultural resource sites. Under the project, ground disturbance and development of new structures would occur,resulting in potentially significant impacts related to the potential disturbance of undiscovered/unrecorded subsurface archaeological sites and human remains. These impacts would be reduced to less-than-significant levels after mitigation. However,because the Increased Land Disposal Alternative would also include new development or ground disturbance, it could also result in the disturbance of previously undiscovered subsurface archaeological resources and/or human remains. Therefore, cultural resources impacts would be similar under this alternative.[Similar] Fisheries and Aquatic Resources The Increased Land Disposal Alternative would result in greater impacts to fisheries and aquatic resources compared to the project. The existing WQCF does not comply with one objective of the Thermal Plan. While the project would increase the effluent discharge rate to 27 mgd,which would result in the exceedance of all three thermal plan objectives(see Section 4.13, "Fisheries and Aquatic Resources"),mitigation is recommend that would require the construction of cooling towers at the WQCF. The cooling towers would bring the WQCF's effluent in compliance with all three objectives of the Thermal Plan and would eliminate the WQCF's existing exceedance of one Thermal Plan objective. This alternative would not eliminate this exceedance;therefore, thermal impacts would be greater under this alternative.[Greater] 7.3.3 ADVANCED WASTEWATER TREATMENT ALTERNATIVE Because the proposed project includes nitrification-denitrification,tertiary filtration and UV disinfection facilities, the remaining advanced wastewater treatment options available to the City are microfiltration and reverse osmosis (MF/RO). RO is a membrane separation process that is used for the removal of dissolved constituents from wastewater remaining after advanced treatment with tertiary filtration or microfiltration. RO treatment relies on applied pressure to force water through a semi-permeable membrane while restraining the passage of particulate and high molecular weight constituents. Membranes exclude ions,but require high pressures to produce the deionized water. Passage of water through the membrane produces a relatively ion free effluent stream and a concentrated brine stream. MF occurs prior to RO in order to remove larger organic and inorganic particles that foul the RO membrane and thus increase membrane resistance to water flow and reduce membrane service life. The Advanced Wastewater Treatment alternative would involve the implementation of advanced microfiltration and reverse osmosis (MF/RO)technology. In order to maintain existing water quality and TDS loadings in the San Joaquin River from the time the WQCF reaches its current permitted capacity of 9.87 mgd ADWF through the proposed buildout capacity of 27 mgd ADWF, it is estimated that a maximum MF/RO capacity of 21 mgd would be required(LWA 2007). This alternative assumes that the blending of effluent streams of different qualities is permitted and,therefore,only a portion of WQCF tertiary effluent would need to undergo MF/RO prior to blending with non-MF/RO tertiary effluent and discharge to the San Joaquin River. Manteca WQCF and Collection System Master Plans EIR EDAW City of Manteca 7-9 Alternatives to the Proposed Project