ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

Home Browse Search

are consistent with NPDES permit limitations. However,project treated effluent pollutant concentrations would be slightly higher than No Project Alternative treated effluent pollutant concentrations. The project will produce pollutant concentrations that are consistent with applicable regulatory criteria/objective and NPDES permit limitations,and consistent compliance with applicable water quality criteria/objectives and NPDES permit limitations would be considered protective of aquatic resources (and would therefore not adversely affect fisheries and aquatic resources). However,as previously discussed,project treated effluent pollutant concentrations would be slightly higher than No Project Alternative treated effluent pollutant concentrations. This slight increase in treated effluent pollutant concentration would have a small adverse affect (i.e., increased impact) on fisheries and aquatic resources compared to the No Project Alternative. Therefore,the No Project Alternative would result in slightly less water quality impacts compared to the project.[Less] Regarding thermal impacts,the No Project Alternative would result in slightly greater impacts to fisheries and aquatic resources compared to the project. The existing WQCF does not comply with one objective of the 1972 "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of California,"also referred to as the Thermal Plan. While the project would increase the effluent discharge rate 27 mgd,which would result in the exceedance of all three thermal plan objectives(see Section 4.13, "Fisheries and Aquatic Resources"),recommended mitigation would require the construction of cooling towers at the WQCF. The cooling towers would bring the WQCF's effluent into compliance with all three objectives of the Thermal Plan and would eliminate the WQCF's existing exceedance of one Thermal Plan objective. The No Project Alternative would not eliminate this exceedance. Overall,because the No Project Alternative would result in less water quality impacts, fisheries and aquatic resources impacts would be similar under this alternative.[Similar] 7.3.2 INCREASED LAND DISPOSAL ALTERNATIVE The Increased Land Disposal Alternative would maximize the discharge of treated effluent to nearby agricultural lands. In order to maintain existing water quality and constituent loadings to 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 effluent-to-land disposal capacity of 18 mgd would be required. Treated effluent from the WQCF is currently either land applied to approximately 190 acres of City-owned land or discharged to the San Joaquin River. The City has examined a number of effluent-to-land disposal strategies that would have sufficient capacity for disposal of 18 mgd of treated wastewater year-round. Because of the relatively high unit cost and other implementation constraints of urban water reuse,the increased land disposal alternative would apply undisinfected, denitrified, secondary effluent to existing City-owned land surrounding the WQCF and to future City-purchased land at some distance from the WQCF. While the City has examined the costs of purchasing land from one to 10 miles away for effluent disposal, economic considerations and land availability make the purchase of land farther away from the WQCF a more tenable proposition. To that end,the increased land disposal alternative includes high-rate irrigation(260 in/yr)of City-owned land at the WQCF property(4,600 ac-ft/year or 4.11 mgd) and agricultural irrigation on acreage within 10 miles of the WQCF that would be purchased by the City(15,560 ac-ft/year or 13.89 mgd)as a means of collectively applying 18 mgd of undisinfected, denitrified, secondary effluent to land year-round. This alternative would allow the reclamation of up to approximately two thirds of WQCF effluent at the proposed build-out capacity of 27 mgd ADWF. Additional pipelines would be required to convey treated effluent from the WQCF to the selected land disposal site.All facilities proposed at the WQCF to treat up to 27 mgd of wastewater and proposed collection system and recycled water distribution pipelines would be constructed under this alternative. EDAW Manteca WQCF and Collection System Master Plans EIR Alternatives to the Proposed Project 7-6 City of Manteca