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Resolution 1990-68 ~, . . ',SL RESOLUTION NO. 90-68 RESOLUTION OF THE CITY COUNCIL OF GILROY MAKING CERTAIN FINDINGS REQUIRED BY THE CALIFORNIA ENVIRON- MENTAL QUALITY ACT IN CONNECTION WITH A PROJECT CONSISTING OF ADOPTING A LONG-TERM WASTEWATER MANAGEMENT PLAN FOR THE CITIES OF GILROY AND MORGAN HILL FOR WHICH AN ENVIRONMENTAL IMPACT REPORT HAS BEEN PREPARED. W~EREAS, the wastewater treatment plant servicing the cities of Gilroy and Morgan Hill has nearly reached capacity, virtually all residential, commercial and industrial growth for the past few years has been very limited, and future growth will be severely curtailed unless additional sewage capacity is provided; and WHEREAS, at the direction of the two cities, James M. Montgomery Engineers analyzed alternatives for sewage treatment expansion as described in their Wastewater. Management Alternative Analysis and Long Term Draft Project Report ("Montgomery Engineers Report") dated July 1984; and WHEREAS, for more than six years expansion of sewage treatment capacity has been studied by James M. Montgomery Engineers as consultants to the two cities, by the citizens Sewer Advisory Committee, by the Joint Powers committee of the two city Councils, and by the City Councils themselves; and WHEREAS, in 1986 the Council adopted a Long Term Wastewater Management Plan ("Plan"), described as alternative SL (Winter Surface Discharge to the pajaro River and Summer Land Treatment) as discussed in the Montgomery Engineers Report and the Final Environmental Impact Report for the Long Term Wastewater Management Plan of the cities of Gilroy and Morgan Hill dated March 1986, prepared by Earth Metrics Incorporated ("First Final EIR"), hereinafter referred to as the "Project"; and WHEREAS, prior to drafting an environmental impact report ("EIR") the lead agencies held two agency scoping meetings and three public scoping meetings both within and without the County of Santa Clara to provide an opportunity for interested persons to comment on topics they would like addressed in the EIR; and WHEREAS, such proj ect was the subj ect of a program EIR prepared for the cities of Gilroy and Morgan Hill as lead agencies, and the Council held a public hearing on the draft EIR on December 14, 1985 for public comment, and a public meeting on April 8, 1986 to consider the proposed First Final EIR; and WHEREAS, On July 29, 1986, by Resolution 86-45 the City Council of Gilroy, and on August 6, 1986 by Resolution 3075 the City Council of Morgan Hill, adopted the findings required by FINDSL1.DOC 01501-005 07/11/90 RESOLUTION NO. 90 - 68 -1- , ' , . . . CEQA in connection with their adoption of Alternative SL for the Long Term Wastewater Management Plan; and WHEREAS, two lawsuits were filed against the two Cities, each seeking to overturn the selection of the alternative selected for the Plan. The suits were coordinated as the "Gilroy/Morgan Hill Environmental Cases", Judicial Council Coordination Proceeding No. 2043 (the "Lawsuit"); and WHEREAS, On June 29, 1988, Judge Peter G. stone issued a Peremptory writ of Mandate (the "Writ") in the Lawsuit. The writ rej ected most of the challenges that had been brought in the Lawsui t and upheld the adequacy of the First Final EIR in most respects, but did order that a new EIR be prepared to treat the following issues: a) Cumulative impacts to the waters of the pajaro River and pajaro Estuary b) Cumulative impacts on groundwater c) Cumulative impacts on waters of Monterey Bay d) Cumulative air pollution impacts e) Analysis of al+ potential significant impacts for which analysis was deferred to later stages of the project f) Analysis of whether mitigation measures exist to avoid or substantially lesson significant effects for which monitoring was proposed as sole mitigation g) Analysis of whether the above mitigations are feasible h) Appropriate findings regarding infeasibility of mitigations, if necessary; and WHEREAS, The Cities have prepared a new Draft Eir dated January 1990. The Draft EIR was circulated for comment, and numerous comments were received in wiritten form, as well as orally at a public hearing held on February 26, 1990. As a result of this process, a Final EIR dated May 1990 (the "Final EIR") was prepared, incorporating the Draft EIR, all comments received, responses to the comments, the transcript of the public hearing, and additions, deletions and changes to the Draft EIR; and WHEREAS, The cities at a joint special meeting held on June 11, 1990 each certified that the Final EIR was complete and in accordance with CEQA; and WHEREAS, The cities at a joint special meeting on July 11, 1990, held a public hearing to obtain public input on the choice of a Long Term Plan Alternative; and WHEREAS, CEQA requires that, in the approval of a project for which an EIR has been prepared, the decision-making body shall review and consider the final EIR prior to approving the FINDSL1.DOC 01501-005 07/11/90 -2- , . . . project and make certain findings regarding the significant effects on the environment identified in said final EIR; and WHEREAS, CEQA also requires that in determining to carry out a project for which an EIR has been prepared, the lead agency must also adopt a mitigation monitoring plan, which each city will adopt by companion resolution of even date; NOW, THEREFORE, City of BE IT RESOLVED by the city council of the as follows: 1. CEOA CERTIFICATION: The Council as the decision-making body hereby certifies that the Final EIR of May 1990 is complete in accordance with CEQA, that said Final EIR was presented to it and that it has reviewed and considered the information contained in the Final EIR prior to approving the Project. 2. SIGNIFICANT ENVIRONMENTAL EFFECTS IDENTIFIED IN THE FINAL EIR FOR ALTERNATIVE SL Hydroloqv/Water Resources H1. SIGNIFICANT EFFECT: possible construction of percolation ponds (123 acres) within the 100 year flood plain reduces existing flood storage areas and creates a potential increase in flooding hazards to other uses in the area. EXPLANATION OF MITIGATION OR AVOIDANCE: Alternative SL requires 123 acres for percolation ponds in addition to those already existing at the wastewater treatment facility. The most suitable acreage is located in sites 12 (140 acres) and/or 19 (1,180 acres), those sites totaling 1,320 acres. The 123 acres for SL will be selected from the 1,320 acres available, and to the extent possible should be constructed outside the 100-year flood plain. Considerations of topography and final disposal pond design may prevent complete avoidance of the flood plain, but this alternative requires less acreage for ponds than Alternatives Land LD. Design and placement of ponds required within the 100 year floodplain shall be coordinated with the Santa Clara Valley Water District in order to minimize potential increased flooding hazards. FINDING: Implementation of this alternative with the above mitigation incorporated will avoid potential flooding hazards by location of ponds outside the 100 year floodplain or substantially lessen such hazards to an acceptable level by design and placement of the ponds. H2. SIGNIFICANT EFFECT: Additional percolation wastewater recharge to the upper semi-perched aquifer of the Llagas Subbasin would potentially result in oversaturation of the upper aquifer, resulting in elevated groundwater levels and potential FINDSL1.DOC 01501-005 07/11/90 -3- . . agricul tural impacts and spillage to the north to the deeper aquifer. EXPLANATION OF MITIGATION OR AVOIDANCE: There is a potential problem for land disposal sites where high groundwater occurs as a result of percolation pond recharge. One possible mitigation would be to construct dewatering wells or underdrains to lower the groundwater levels as necessary. Unfortunately, it might become necessary to discharge to the Pajaro River from such underdrains or dewatering wells occasionally during the summer months (for example, possibly after an exceptionally wet winter) . This summer discharge in turn would cause the following significant effects: (1) Potential turbidity impacts to downstream beneficial uses of the Pajaro River as a result of channel scouring if wastewater discharge is pumped into the river in late summer; (2) Possibility of channel erosion and scouring in the Pajaro River due to increased stream flows increasing sediment load and turbidity, altering the benthic invertebrate communities in the affected area, affecting filter feeding fish and burying nonmotile benthic organisms; (3) Potential impacts to available habitat and optimum growth and spawning water temperatures for steelhead trout caused by elevated temperatures of effluent discharge to the pajaro River during summer months. Instead of using underdrains or dewatering wells, the cities will mitigate this potential effect by drawing off sufficient treated effluent to use it as reclaimed water either on city lands for irrigation or for sale to commercial customers as necessary during the summer months. There is a discussion of the use of reclamation as a disposal method in the Montgomery Engineers Report (pp 3-8 to 3-12). That report concludes that reclamation cannot be the primary method of disposal, but that landscape and agricultural irrigation are feasible as auxiliary methods of disposal in the summer months, as would be the case here. Monitoring of groundwater levels will be a standard part of the operations of the plant, and will be required by the terms of its discharge permit. This monitoring will enable the cities to determine when they are approaching the holding capacity of the land disposal sites. Prior to approaching this holding capacity, the cities shall arrange for such reclamation use in sufficient quantities to completely mitigate this potential effect. If it becomes impossible to find users (including the cities themselves) for sufficient quantities of effluent, then the cities shall purchase sufficient acreage (e.g., at sites 11 and/or 14 or similar property) to allow sufficient additional land disposal to prevent saturation of the disposal sites, and thus fully mitigate this impact. FINDING: The project incorporates mitigation measures FINDSL1.DOC 01501-005 07/11/90 -4- '. . . which avoid or substantially lessen the significant environmental effect thereof. H3. SIGNIFICANT EFFECT: Increased pajaro River streamflows could result in significant bank erosion potential, to the extent that dispersive soils are present. EXPLANATION OF MITIGATION OR AVOIDANCE: A survey will be conducted to locate any significant areas of dispersive soils along the pajaro River, downstream of the San Benito River confluence. If dispersive soils are found, river banks in these areas will be stabilized with vegetation to prevent erosion. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. FINDSL1.DOC 01501-005 07/11/90 -5- . . WATER QUALITY WQ1. SIGNIFICANT EFFECT: Discharge of wastewater to the pajaro River could have a significant effect on domestic users downriver from the discharge point. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: There are at least 18 residences along the Paj aro River which obtain their water either directly from the river' or from wells directly adjacent to the river. Such use is not recommended, particularly for drinking water, even without the proposed discharge into the pajaro River due to the uncertainty of the existing water quality of the river. Accordingly, at present these domestic users should secure al ternati ve domestic water sources or use domestic water treatment. If the discharge of waste water to the pajaro degrades the quality of their domestic water further, that would make such provision of al ternati ve sources or treatment more important. The cities of Morgan Hill and Gilroy cannot enforce such a requirement, since these residences are located outside of their territorial limits. The County of San Benito Health Department is urged to work with each such domestic water user to ensure that an adequate water source is available. FINDING: The project identifies mitigation measures which substantially lessen or avoid the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public utilities to mitigate. In view of the cities' need for sewage capacity, the environmental risk will be tolerated as an acceptable level of impact. WQ2. SIGNIFICANT EFFECT: Percolation pond effluent would exceed Basin Plan groundwater quality objectives for inorganic salts, i.e., total dissolved solids, sodium, chloride and sulfate, potentially causing groundwater quality deterioration of the upper semi-perched aquifer of the Llagas Subbasin. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: Disposal into the shallow upper aquifer is less critical than disposal into the deeper aquifer potentially associated with alternative L (Land Disposal). The lower aquifer is considered to be important for water supply by the Santa Clara Valley Water District, whereas the upper is not. Groundwater monitoring as required by the Regional Water Quality Control Board shall be continued to identify potential impacts due to inorganic salts at the earliest possible stage. Current practice for groundwater recharge wastewater treatment processing does not include removal of inorganic salts. In addition to "objectives," which are more FINDSL1.DOC 01501-005 07/11/90 -6- , ' . . in the nature of goals, the Basin Plan contains standards for discharges, which are the actual recommendations that should be met. Disposal of the effluent to be produced from the expanded plant is consistent with Basin Plan standards and with normal restrictions put on effluent discharges in the basin. The Basin Plan requires It reasonable control" of water qual i ty factors, which does not include treatment to limit salts. Processes to remove salts are costly, require large amounts of energy and involve additional environmental and resource impacts associated wi th the disposal of the resultant salt brines. For other constituents, the effluent should be treated, to the extent possible, to meet Basin Plan objectives. The cities acknowledge the extensive discussion in the Final EIR concerning the possible use of reverse osmosis (R. 0.) to remove TDS from the treated effluent. In particular, the cities received detailed letters from the Attorneys representing the Committee for Progressive Gilroy and from Dr. Larry Russell, an expert hired by them, advocating the use of R.O. for this purpose. These letters are included in the Final EIR. Also included in the Final EIR are responses by the preparers of the EIR to the contents of these letters, as well as a report from Montgomery Engineers discussing the contents of the two letters and analyzing in further detail the feasibility of TDS mitigation (Final EIR, app. I). This is all in addition to the original, detailed discussion contained in the Draft EIR at pp. 3.3-35 to 3.3-39. Having carefully reviewed and analyzed this material regarding possible mitigation of TDS, the cities conclude that full mitigation by the use of R.O. or a similar post-treatment method is not feasible, and do not incorporate such mitigation into the project. On the other hand, it is feasible to partially mitigate the TDS impact through source controls, similarly to the way that source controls mitigate the intake of hazardous materials. The cities therefore will adopt the following partial mitigation for. TDS: Local pretreatment ordinances will be expanded to include limits for TDS levels released into the wastewater system. These will include pretreatment limitations for TDS and water monitoring for water softener companies, as well as educational programs to inform the public of the TDS effects of using water softening equipment. In addition, the discharge will have to comply at all times with limits set by the Regional Water Quality Control Board for TDS discharge in the discharge permit under which the plant will be operated. The primary reasons for the citiesl finding that R.O. is not a suitable or feasible mitigation for TDS impacts to groundwater are the following: (1) Reverse Osmosis is removing TDS from treated effluent. not a proven technique for There is one model plant, FINDSL1.DOC 01501-005 07/11/90 -7- , . . . " "Water Factory 21", which has been in operation in Fountain Valley, California for almost 20 years, without serious imitator in the United states. This plant treats only about 10% of the operating district's wastewater flow. Both operating and capital costs are high. Water Factory 21 also has the benefit of special circumstances, in that it is able to dispose of the resul ting brine through a preexisting ocean outfall. This is not true for Gilroy, where the cost and environmental impacts of an ocean outfall would be practically the same as for disposing of the effluent, without R.O., through the so alternative (direct discharge of 'treated effluent to Monterey Bay). The total capitol cost of an R.O. facility is estimated at $89 million, with present net worth operating costs of $56 million (as compared to a total cost of $117 for the treatment plant itself). (2) TDS removal processes are very energy intensive. The R.O. process analyzed in the Final EIR would require 2550 horsepower to operate. The utilization of this energy would result in significant air pollution emissions. If this energy were supplied by an oil-fueled power plant, estimated annual air pollution emissions would be approximately 15 tons of NOx, 51 tons of SOx, 2.5 tons of CO, and 2 tons of particulates. (3) Any TDS removal process generates a large quantity of brine (salt waste). As shown in Table 3.3.4 in the Final EIR, the TDS removal process can generate as much as 32 tons per day of salt waste. The amount of concentrated salt waste is generally equal to or greater than the salts present in the treated water. Dr. Russell suggests that solar evaporation be used to dispose of the brine. This is not practical in Gilroy. The climate is such that annual rainfall can exceed annual evaporation for several years in a row. As evaporation rates from brine are significantly lower than from freshwater, any brine ponds established in Gilroy would be permanently wet. Such a pond would pose the same type of threat to groundwater supplies as a hazardous waste pond, and consequently should be designed to similar rigorous standards for siting and construction. The apparent policy of the State at this time is to eliminate existing liquid hazardous waste impoundments, and prevent new 0nes. A waste that contained extremely high concentrations of salt as well as measurable concentrations of the heavy metals present in the Gilroy wastewater would probably have to be handled in a similar manner as a hazardous or designated waste. The remaining possibility is to dispose of the brine in a secure landfill. The concentration of salt may, in fact, be classified as a hazardous waste and require disposal as such. At present, the practical experience with TDS removal from municipal wastewater is extremely limited, and the State has not established standardized criteria that specifically address the acceptable disposal of salt brines produced by TDS removal. The FINDSL1.DOC 01501-005 07/11/90 -8- '. . . future availability of disposal sites is thus uncertain. The cities do not believe it would be a sensible decision to plan a major TDS removal facility when the ability to dispose of the substantial quantities of brine is not assured. FINDING: This impact will be partially mitigated by the imposition of source controls for TDS removal and the other procedures described above. Full mitigation through TDS removal from the treated wastewater is not practical or feasible for this plant. The removal of inorganic salts is not a standard sewage treatment process, and has serious environmental consequences associated with it, particularly involving the large amounts of energy required and the difficulty of disposing of the resulting brine. Such treatment of the effluent is not required by Basin Plan standards, nor is it expected to be required by the Regional Water Quality Control Board, which will set waste discharge requirements for the plant. The EIR does not specifically recommend treatment to meet Basin Plan groundwater objectives with respect to inorganic salts. Except for alternatives SO (surface discharge to the ocean) & SP (surface discharge to the pajaro River), which raise other environmental issues, all other alternatives including the No Project alternative have the same potential for groundwater quality deterioration. Therefore, in view of the cities' need for sewage capacity to support existing and planned urban uses, the environmental risk will be tolerated as an acceptable level of impact. WQ3. SIGNIFICANT EFFECT: Potential degradation to groundwater, Llagas Creek, and pajaro River water quality on an infrequent, temporary basis from accidental discharges of untreated or partially treated sewage due to plant shutdown or failure, industrial pretreatment failure and chemical spills, or a major seismic event. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: The treatment plant shall be designed to include prov1s1ons for emergency storage capacity and emergency standby power to provide immediate response to plant shutdown or failure. Influent and effluent monitoring shall be required to detect industrial pretreatment failure and chemical spills. The design of the facilities and structures shall comply with seismic requirements of the current Uniform Building Code. Some unavoidable discharges would occur as a result of a major earthquake, but the extent of spillage at the plant would be limited by probable breakdowns in the sewer collection pipelines and the water system. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect, and in view of the need for sewage capacity, the cities will tolerate any remaining environmental risk as acceptable. FINDSL1.DOC 01501-005 07/11/90 -9- . . Bioloqy B1. SIGNIFICANT EFFECT: Percolation pond disposal of treated effluent would potentially impact adjacent trees due to excessive water in the root zone. EXPLANATION OF MITIGATION OR AVOIDANCE: Effluent shall be applied at the rates recommended in the Montgomery Engineers Report and consistent with proper engineering practice to avoid oversaturation. The final engineering plans for the land disposal areas shall avoid the riparian vegetation areas. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B2. SIGNIFICANT EFFECT: Increased Paj aro River stream flows could potentially alter migration responses in Steelhead trout with resultant effects of fish stranding and increased susceptibility to poaching and disease. EXPLANATION OF MITIGATION OR AVOIDANCE: Large discharges to the river shall be timed with, to the extent possible, the commencement of winter rains and higher stream flows to minimize potential steelhead migratory responses. FINDING: The proj ect incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B3A. SIGNIFICANT EFFECT: Wet season discharge of wastewater to the pajaro River containing copper and ammonia without sufficient dilution could create an avoidance response in steelhead, resulting in potentially significant impact to steelhead populations. EXPLANATION OF MITIGATION OR AVOIDANCE: Steelhead trout migration patterns in the pajaro River shall be monitored prior to commencing to discharge treated wastewater into the paj aro River channel, and also after the treatment plant is operational and wet season discharges are being made to the pajaro River. If avoidance responses are found to be occurring downstream of the Uvas/Carnadero Creek confluence, then measures to reduce residual ammonia and copper in treated wastewater will be implemented. (Note that although pretreatment for mercury is mentioned erroneously as a mitigation measure in the Final EIR, the data do not support the necessity for such pretreatment, so the cities do not adopt it as a mitigation). Measures to remove residual ammonia consist of further denitrification. Measures to FINDSL1.DOC 01501-005 07/11/90 -10- .:,' , " . . reduce copper consist of more stringent pretreatment regulation and/or modifications of the treatment process to extract copper. If is is found that Steelhead avoidance does not occur downstream of the Uvas/Carnadero Creek confluence but does occur upstream of this confluence, then the outfall shall be relocated to a point below the Uvas/Carnadero Creek confluence. In any case, the cities believe that the impact will be fully mitigated. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B3B. SIGNIFICANT EFFECT: Elevated temperatures of effluent discharged to the Pajaro River may have significant adverse impacts on steel head smol t transformation necessary for ocean life and smolt survival on the way to the ocean from the pajaro River tributaries, as well as to the vigor and health of spawning adults. EXPLANATION OF MITIGATION OR AVOIDANCE: Final treatment plant design shall incorporate suitable cooling facilities (such as cooling ponds, spray ponds, or cooling towers) to ensure that discharge temperatures do not exceed ambient river temperatures. FINDING: The proj ect incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B4. SIGNIFICANT EFFECT: pajaro River fish could potentially be impacted to the extent that erosion and turbidity is increased between winter storms. Potentially significant impacts could result affecting Sacramento blackfish, Sacramento squawfish, Three spined stickleback, and a small Steelhead population downstream of the San Benito River confluence. EXPLANATION OF MITIGATION OR AVOIDANCE: A survey will be conducted to locate any significant areas of dispersive soils along the pajaro River, downstream of the San Benito River confluence. If dispersive soils are found, river banks in these areas will be stabilized with vegetation to prevent erosion. Establishment of vegetation on'barren or eroded streambanks would mitigate increased erosion and turbidity caused by the possible presence of dispersive soils along the pajaro River. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. Note that this is listed on page 7-1 of the Final EIR as an impact that cannot be fully mitigated for Alternatives LD, SL, and SP. For Alternative SL, however, since direct discharge to the River will not occur during the summer months, the cities find that in fact the impact is fully mitigated for the project as proposed with mitigation measures. FINDSL1.DOC 01501-005 07/11/90 -11- . . B5. SIGNIFICANT EFFECT: Daily variation in treatment plant discharges could result in abnormal variation of salinity and temperature and area submerged and exposed, resulting in potentially significant impacts to pajaro River and estuary habit. EXPLANATION OF MITIGATION OR AVOIDANCE: Impacts to fish and aquatic wildlife resulting from daily fluctuations of effluent discharges will be mitigated by treatment plant design and operation that moderate daily fluctuations and release effluent at a nearly constant rate. For example, flow equalization basins and/or sufficient retention ponds will be constructed to retain wastewater during peak production periods to be released at a more steady rate throughout the day and night. Shading will be encouraged around retention ponds to reduce some warming of the water by the sun. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B6. SIGNIFICANT EFFECT: Increased flows in the pajaro River could result in increased breaches of the sandbar at the mouth of the paj aro Estuary, which could result in potentially significant impact to fish habitat as well as the wildlife that eat the fish, including the Double-crested Cormorant. EXPLANATION OF MITIGATION OR AVOIDANCE: The frequency of sandbar breaching at the pajaro Lagoon shall be monitored prior to and after discharges from the wastewater treatment plant operation. If the frequency of sandbar breaching increases significantly from treatment plant discharges and adversely affects fish and wildlife habitat, then a culvert or pump will be installed. The installation of a culvert or pump will regulate water levels to prevent significant changes in salinity or temperature, which will reduce this impact to insignificance. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B7. SIGNIFICANT EFFECT: The Construction of the pipeline could potentially significantly impact breeding habitat of the Red-legged Frog and California Tiger Salamander. Loss of riparian habitat along the pajaro River from pipeline or outfall construction could have a potentially significant impact on the Yellow Warbler and Yellow-breasted Chat. EXPLANATION OF MITIGATION OR AVOIDANCE: The final engineering plans will avoid the riparian vegetation areas where feasible. Every attempt will be made to avoid impacts to FINDSLl.DOC 01501-005 07/11/90 -12- . . " sensitive and significant botanical resources (trees with trunk diameters greater than 18" in diameter). Potential impacts to Red-legged Frog and California Tiger Salamander will be avoided by surveying the actual locations where habitat would be disturbed by construction and avoiding any habitat that is actively in use by either of the species. Construction impacts to riparian habitat will be reduced to insignificance by the following mitigation measures: Construction operations (including grading) shall be restricted to the pipeline construction corridors to the extent possible to minimize vegetation loss. Construction activity shall occur out of the riparian corridor, except where designated and where replacement mitigation has been approved. A buffer zone of 251 in width, measured outward from the riparian corridor, shall be established. All construction activities, including storage of materials, discarding of spent material, and construction staging should occur outside of the buffer zone. The buffer zone shall be fenced with plastic mesh "snow fencing" or chain link fencing prior to construction, such that the integrity of the buffer is maintained. The loss of riparian habitat will be mitigated by compliance with the permit requirements of the Department of Fish and Game, calling for a one to one replacement (or greater) of impacted riparian habitat. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B8. SIGNIFICANT EFFECT: The discharge of freshwater into the pajaro River may cause significant impacts to salt marsh vegetation if there are significant changes in soil salinity. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: The only possible mitigations for the fact that the discharged effluent will lower the salinity in the lagoon would be to increase the salinity of the effluent. This would cause even greater impacts upon the fresh water habitat of the pajaro River for the entire length of the river from the discharge point to the salt marsh lagoon. Because these impacts on water quality and fresh water biologic habitat would likely be more severe than the relatively limited impact that may be caused by the fresh water discharge upon the salt marshes, the cities find that such mitigation is not appropriate and is therefore infeasible (however, this impact may be reduced if it is decided to install an outlet culvert or pump that would allow salt water intrusion back into the marsh). Thus, there is no practical and feasible full mitigation for impacts to salt marsh vegetation caused by changes in soil salinity. FINDING: The salt marsh vegetation and habitat is not unique; and the impact upon it from the discharge of the treated effluent is somewhat speculative. On the other hand, the impact from any poten~ial mitigation that would increase the salinity of FINDSLl. DOC 01501-005 07/11/90 -13- . . the effluent would be much more severe and definite upon the entire fresh water habitat of the pajaro River from the discharge point all the way downstream. In view of the speculative nature of the impact upon the salt marsh vegetation, and the clear environmental tradeoff that would ensue from lowering the salinity of the effluent, the cities regard full mitigation as infeasible. In view of the need for disposal capacity, the cities will tolerate any remaining environmental risk as acceptable. B9. SIGNIFICANT EFFECT: The uptake of trace amounts 9f heavy metals in the effluent could potentially impact riparian vegetation. The significance of this impact is not known. EXPLANATION OF MITIGATION OR AVOIDANCE: Vegetation along the pajaro River shall be monitored downstream of the discharge point to determine if any adverse impacts are resulting from uptake of heavy metals present in the effluent. If it is determined that heavy metals are adversely affecting riparian vegetation, more stringent pretreatment standards will be implemented to reduce these metals in the effluent to reduce this impact to insignificance. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. BID. SIGNIFICANT EFFECT: Nickel in the effluent could result in potentially significant toxic impacts to diatoms, invertebrates, and fish (including Steelhead embryo and larvae). EXPLANATION OF MITIGATION OR AVOIDANCE: Effluent discharged to the pajaro River will receive industrial pretreatment and comply with Basin Plan effluent limitations. In addi tion, nickel concentrations in treated wastewater will be reduced sufficiently through treatment and pretreatment to maintain existing concentrations of nickel in the Paj aro River during both wet season discharge and dry season land disposal. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. B11. SIGNIFICANT EFFECT: The loss of grassland, agricultural lands and ruderal habitat from land disposal sites could result in a potentially significant impact to Black- shouldered Kite, Northern Harrier, and Burrowing Owl. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: Some loss of habitat resulting from construction of the land disposal sites can not be mitigated, although Alternative SL has the benefit, as compared to alternatives Land LD, of requiring less acreage for land disposal sites, thereby lessening the loss of FINDSL1.DOC 01501-005 07/11/90 -14- . . agricultural land as well as the potential impact to the three species of birds mentioned above. Providing suitable replacement habitat would require alteration of other non-grassland habitat to adapt it for the three above species. This would diminish the habitat value of the replacement land and result in additional biological impacts. Replacement habitat could also be created by the conversion of existing urban land to grassland. However, due to the large amount of land required, the Cities find that this would be infeasible. FINDING: This impact cannot be mitigated, since by its very nature the provision of land disposal sites will result in some loss of terrestrial habitat. For the reasons given above, provision of suitable replacement habitat is infeasible.In view of the benefits of this project, as well as the fact that these species of birds are not rare, endangered or threatened, this impact is deemed acceptable. B12. SIGNIFICANT EFFECT: There may be potentially significant impacts on fishery resources due to secondary effects of the project, i.e., impacts caused not directly by the project, but rather by growth that will result in part from implementation of the Long-Term Plan. This growth is of course contemplated by the general plans of Giroy and Morgan Hill, and the implementation of the Long-Term Plan would have the effect of removing a present impediment (lack of disposal capacity) to allowing the contemplated and planned-for growth to occur. These impacts could include habitat degradation, increased stranding of Steelhead migrants, increased Steelhead poaching and increased risk of mortality due to illegally discharged toxic chemicals. EXPLANATION OF MITIGATION OR AVOIDANCE: This is a potential impact resulting from increased urban development. The magnitude or severity of these impacts would be dependent upon the location and nature of each urban development, as well as upon various societal factors. For example, it is really speculative to conclude that there would be increased fish poaching due to a greater urban population--it is also possible that a greater urban population would reduce opportunities for fish poachers to operate undetected, and in any event, law enforcement and the attitude of residents towards such matters may well prove to be more important than any simple extrapolation of an impact from an increase in population. with respect to modifications to the channels of the pajaro River or Uvas Creek, impacts shall be mitigated by complying with the requirements of a Stream Alteration Agreement from the California Department of Fish and Game; such permits would include provisions to mitigate any impacts to the riparian habitat. Protection of the riparian habitats is currently covered by several development policies of the City of Gilroy: for example, requiring that in natural drainage areas development FINDSL1.DOC 01501-005 07/11/90 -15- . . be restricted for a greater distance of 250 feet from the center of a stream, or within the lOO-year flood plain. Increased runoff is reduced by requiring that areas within the Llagas Creek storm drainage system be connected to that system, while developments outside that area require detention basins. Morgan Hill is also requiring detention basins where appropriate to reduce runoff into stream corridors. Dumping of toxic chemicals is expected to continue to be regulated by existing laws, including the pretreatment ordinances. In summary, while urban development can be expected to have potentially significant biological impacts, it is expected that continued application of existing practices and regulations, and continuing review of development applications for conformance with General Plan policies and procedures will mitigate these effects. Further analysis of these impacts and mitigations is beyond the reasonable scope of this EIR, and should be carried out in the context of the cities' general plans, as the same are updated from time to time, and in the review of specific development projects. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. FINDSL1.DOC 01501-005 07/11/90 -16- . . Air Quality/Odor AQ1. SIGNIFICANT EFFECT: Emissions of construction-related dust would create potentially significant short-term air quality effects on localized areas adacent to construction activity. EXPLANATION OF MITIGATION OR AVOIDANCE: standard dust- control construction measures required by the BAAQMD (as set out in detail in Table 3.5.6 in the Final EIR) to minimize potential particulate impacts resulting from construction activities will be implemented to reduce these impacts to an insignificant level. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. AQ2. SIGNIFICANT EFFECT: Odor resulting from various unit processes (primary clarifiers, headworks, influent Parshall flumes, oxidation ditch, anaerobic digesters, sludge thickeners) at the treatment plant would create potentially significant impacts to adjacent sensitive land uses. EXPLANATION OF MITIGATION OR AVOIDANCE: Odor impacts can be fully mitigated through the use of standard odor controls in the design of the facilities. The facility headworks will be covered and the recovered off-gases will be scrubbed. potential headworks odors may also require in-sewer chemical treatment to reduce hydrogen sulfide. Standard odor control engineering techniques shall be included in the design of the primary clarifiers. The influent flow measuring structures shall be covered with subsequent off-gas scrubbing if adverse odors occur at this process point. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. AQ3. SIGNIFICANT EFFECT: Incremental increases in regional emissions associated with growth in Morgan Hill and Gilroy would result in potentially significant secondary air quality impacts both locally and in downwind portions of the North Central Coast Air Basin. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: The secondary air quality impacts resulting from growth-related emissions will be partially mitigated by policies and mitigations set forth within the transportation, land use, and/or air quality elements of the General Plans of Gilroy and Morgan Hill. These mitigation measures fall into two groups: transportation control measures and land use measures. FINDSL1.DOC 01501-005 07/11/90 -17- . . Transportation control measures are strategies designed to reduce vehicle trips, shorten vehicle trips or shift trips to nonautomobile modes. Land use measures attempt to develop a land form or land use mix that makes the transportation control measures more feasible or effective. The city of Gilroy is in the process of adopting an updated Circulation Element to its General Plan, which contains the goal of developing and maintaining a balanced transportation system. Specific policies to accomplish that goal are detailed in the Final EIR at page 3.5-15. The City of Gilroy is currently developing an Air Quality Element to its General Plan. This will include and perhaps strengthen the transportation and land use measures elsewhere in the Plan, and examine additional measures to reduce air quality degradation. The Morgan Hill General Plan also includes goals, policies, or actions in the circulation and Land Use Elements that coincide with air quality planning goals. It is not possible to incorporate mitigation measures into this project to fully mitigate these secondary effects on air quality. In fact, the background emission levels are sufficiently high, even without contributions from Gilroy and Morgan Hill, that there would be exceedances of state and federal standards for air quality. The cities do urge other jurisdictions to adopt and enforce measures similar to those discussed above in order to attempt to mitigate these continuing air quality impacts. FINDING: The proj ect identifies mitigation measures which substantially lessen or avoid the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because much of the potential impact is caused by sources outside their jurisdiction and is within the control of other public entities to mitigate. In view of the cities' need for sewage capacity, the environmental risk will be tolerated as an acceptable level of impact. FINDSL1.DOC 01501-005 07/11/90 -18- . . Cultural Resources CR1. SIGNIFICANT EFFECT: Percolation pond preparation, treated effluent disposal and pond maintenance (discing and plowing) on site 19 could potentially impact cultural resources to one known prehistoric site, as well as other yet unrecorded sites. EXPLANATION OF MITIGATION OR AVOIDANCE: Prior to project construction, cultural resource testing of the selected disposal acreage shall be undertaken, including field mapping, sampling and excavation. Final design of land disposal areas will avoid, to the extent feasible, any significant cultural resources identified by the archaeological testing. If a significant cultural resource disturbance is unavoidable, a data recovery program will be implemented under the direction of a qualified archaeologist to preserve the cultural information at the disturbed site. Should archaeological resources (prehistoric or historic cultural materials) be encountered during subsurface construction, work in that area will be stopped and an archaeologist notified. provisions of current state law must then be followed. Should human remains be encountered, the County Coroner IS office shall be contacted. If the remains are of Native American origin, the procedures set forth in Section 7050.5 of the California Health and Safety Code shall be followed. As part of final site design the local Indian community should be consulted to insure mitigation of potential impacts to burial sites and other cultural resources of value to tribal customs. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. FINDSL1.DOC 01501-005 07/11/90 -19- . . Growth Inducinq Impacts GIl. SIGNIFICANT EFFECT: Implementation of the Long Term Plan would have a growth-inducing effect in Gilroy and Morgan Hill by eliminating the current constraint of lack of wastewater treatment and disposal capacity. EXPLANATION OF MITIGATION OR AVOIDANCE: The project is designed for the purpose of accommodating the planned growth of the cities. Development of the wastewater treatment plant will be phased to allow adjustments as necessary in the timing and amount of capacity to match the actual rate of growth for Gilroy and Morgan Hill, as governed by their General Plans and growth management programs. The complete implementation of any alternative will expand wastewater treatment plant capacity to 14.9 mgd. This capacity would be required based upon ABAG and Montgomery Engineers' growth projections for the year 2008. However, growth in Gilroy and Morgan Hill is managed under their General Plans, by Gilroy's Residential Development Ordinance and initiative Measure E in Morgan Hill, and may not reach the 2008 predictions. The phasing of capacity gives the cities the ability to limit the project to conform with actual growth. This phasing is not possible under alternative SO. FINDING: The project is designed to accommodate growth, but incorporates mitigation measures which substantially lessen the further growth-inducing impact of the project itself. GI2. SIGNIFICANT EFFECT: potential effect on the balance between employment and housing in Gilroy and Morgan Hill due to growth in commercial and industrial uses. EXPLANATION OF MITIGATION OR AVOIDANCE: Implementation of any alternative would not differentiate between growth relating to housing and growth relating to employment opportunities, and therefore will not cause imbalance of itself. Continuing implementation of the appropriate policies for balanced growth would reduce this impact to an insignificant level. Both Gilroy and Morgan Hill presently have policies for achieving a balance in jobs and housing, described in the Urban Growth and Development element of Gilroy's General Plan and through growth regulations, along with the General Plan, in Morgan Hill. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. GI3. SIGNIFICANT EFFECT: Employment growth would indirectly create potential pressures for residential development in San FINDSL1.DOC 01501-005 07/11/90 -20- '. . . Benito County, especially in San Juan Bautista and Hollister, if the demand generated for housing and the projected lack of housing supply in the Gilroy and Morgan Hill area by the year 2000 occur. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: continued implementation of City policies for a balance between jobs and housing in Gilroy and Morgan Hill as described in mitigation measure GI2 above will minimize this effect. San Benito County and the cities of San Juan Bautista and Hollister have jurisdiction and control over housing growth within their boundaries to limit development. These jurisdictions are urged to control housing growth within their boundaries in order to prevent or limit the adverse environmental affects resulting therefrom by use of their general plans and appropriate growth control ordinances as necessary. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. FINDSL1.DOC 01501-005 07/11/90 -21- . . Land Use LU1. SIGNIFICANT EFFECT: Acquisition of property for percolation land disposal area would potentially impact affected property owners on site 19 (31 residences). EXPLANATION OF MITIGATION OR AVOIDANCE: Final selection of suitable percolation pond land disposal areas within each candidate site shall avoid, to the extent possible, sites with residential uses. Owners of property rights which must be acquired will receive fair market value for such rights. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. LU2. SIGNIFICANT EFFECT: Conversion of agricultural land due to community growth accommodated by any al ternati ve would contribute to a continuing trend of a cumulative reduction of agricultural land in Santa Clara County. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: with the growth projected by ABAG, the cities, and their consultants for the South county area through the year 2008, this effect is unavoidable. Growth will result in loss of agricultural land for all project alternatives, including the No project alternative, which, as discussed in the Final EIR, predicts growth serviced by septic tanks or individual package treatment plants creating significant environmental concerns regarding groundwater quality. Phasing of the expansion of treatment plant capacity to match actual growth as governed by the cities' growth management programs rather than predicted growth reduces the impact of this effect. FINDING: All project alternatives identified in the Final EIR result in this unavoidable impact including the No Project alternative. Phasing of treatment plant expansion will reduce this impact-. Due to the cities' need for sewage capacity to support existing and planned urban uses, this environmental risk will be tolerated as an acceptable impact. FINDSL1.DOC 01501-005 07/11/90 -22- .,:0" . . Public services and utilities PS1. SIGNIFICANT EFFECT: Uncertainty of landfill availability and capacity, and cumulative solid wastes generated by other development both in and outside the service area, create a potentially significant impact regarding disposal of solid wastes. EXPLANATION OF MITIGATION OR AVOIDANCE: Neither direct wastes, the grit and sludge generated by this alternative, nor secondary wastes of themselves create significant solid waste disposal impacts. However, the cities should enter into agreements with landfill operators or make other arrangements to provide for such disposal. The cities of Morgan Hill and Gilroy and the San Martin area currently have a franchise agreement with the South Valley Refuse Disposal Company of Gilroy for secondary solid waste disposal service. Refuse is disposed of at the company's Pacheco Pass landfill, with current remaining capacity beyond the year 2010. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. PS2. SIGNIFICANT EFFECT: potential impacts on secondary public services and utilities due to increased demands for fire and police protection, water supplies, storm drainage, roadway maintenance, parks and recreation and school services within the Gilroy/Morgan Hill/San Martin service area caused by growth. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: New development occurring in the cities should be evaluated for effects on service providers and conditions of mitigation imposed as required on the development, including but not 1 imi ted to, formation of assessment districts and imposition of development impact fees to finance expansion of services. New development in the unincorporated area is controlled by the County of Santa Clara and it is within County jurisdiction and authority to similarly regulate such growth. The Morgan Hill Unified School District and Gilroy Unified School District should consider methods to increase school capacity, including year-round school terms and double sessions, in addition to financing provided by the state funds or new development impact fees. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. FINDSL1.DOC 01501-005 07/11/90 -23- " . . Traffic and Transportation T1. SIGNIFICANT EFFECT: Growth-induced traffic volumes within the service area would create a potentially significant effect on U. S. Highway 101 and State Route 152, east of U. S. Highway 101, on carrying capacities by the year 2008, and would require roadway improvements to accommodate the traffic. EXPLANATION OF MITIGATION OR AVOIDANCE: The cities of Gilroy and Morgan Hill will continue to plan and fund traffic improvements identified to accommodate growth pursuant to their General Plans. They will monitor traffic growth as new developments are approved, and impose traffic mitigation measures if required to increase capacity along major routes in the cities to accommodate expansion of Highway 101 and State Route 152. The State Department of Transportation, CalTrans, is currently planning the improvement of State Route 152 from two to four lanes between State Route 156 and Bell station. Construction is scheduled to be completed by 1992. CalTrans plans to widen State Route 152 between State Route 156 and U.S. Highway 101 by the year 2000. Long-range plans also call for the widening of u.S. Highway 101 to eight lanes between state Route 152 and Bernal Road, and to six lanes between Gilroy and the San Benito County line to the south. These projects will be completed before the year 2000, and the cities urge CalTrans to complete them expeditiously. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. FINDSL1.DOC 01501-005 07/11/90 -24- " . . Cumulative Impacts CUl. SIGNIFICANT EFFECT: Alternative SL, combined with other wastewater discharges, would increase TDS concentrations in the cumulative discharge to the upper semiperched aquifer, exceeding Basin Plan groundwater quality objectives for inorganic salts and potentially causing groundwater quality deterioration of the upper semi-perched ~quifer of the Llagas subb~sin. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: As shown in Table 5.7 in the Final EIR, the TDS discharged by the treatment plant under alternative SL is only about one-sixth of the total discharge of TDS to the upper semi-perched aquifer (the rest coming from other dischargers and, primarily, from the unsewered area). This cumulative impact can only be partially mitigated. See the discussion under finding WQ2, above, for an explanation as to the mitigation adopted and the infeasibility of further mitigation. The RWQCB is also urged to require similar mitigations on other dischargers. FINDING: This impact will be partially mitigated by the imposition of source controls for TDS removal and the other procedures described above. Full mitigation through TDS removal from the treated wastewater is not practical or feasible for this plant. The removal of inorganic salts is not a standard sewage treatment process, and has serious environmental consequences associated with it, particularly involving the large amounts of energy required and the difficulty of disposing of the resulting brine. Such treatment of the effluent is not required by Basin Plan standards, nor is it expected to be required by the Regional Water Quality Control Board, which will set waste discharge requirements for the plant. The EIR does not specifically recommend treatment to meet Basin Plan groundwater objectives with respect to inorganic salts. Except for alternatives SO (surface discharge to the ocean) & SP (surface discharge to the Pajaro River), which raise other environmental issues, all other alternatives including the No Project alternative have the same potential for groundwater quality deterioration. Therefore, in view of the ci~ies' need for sewage capacity to support existing and planned urban uses, the environmental risk will be tolerated as an acceptable level of impact. CU2. SIGNIFICANT EFFECT: Dry season seepage from project discharges, combined with other discharges, would increase copper concentrations in the pajaro River in the dry season, which is currently in excess of Basin Plan water quality objectives, thereby contributing to potentially significant cumulative water quality impacts upon the pajaro River. FINDSL1.DOC 01501-005 07/11/90 -25- " . . EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: The cities shall adopt more stringent standards for the pretreatment of copper in the influent and/or include additional treatment to maintain existing copper concentrations in the River during the dry season. The Regional Water Quality Control Board is also urged to adopt more stringent standards for other dischargers to reduce this potential impact to a level of insignificance. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect from the- project itself. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. CU3. SIGNIFICANT EFFECT: The cumulative removal of riparian habitat for construction of the discharge pipeline combined with the periodic removal of vegetation for flood control within the pajaro River would result in significant cumulative impacts to riparian vegetation, fisheries, and wildlife (including rare, threatened, endangered, and species of special concern) of the river. EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: Mitigation for the riparian impacts from construction of a line or outfall would be provided for by compliance with the California Department of Fish and Game permit requiring a minimum one to one (1: 1) replacement (or greater) of impacted riparian habitat. See also mitigation discussion under Finding B7 above. Mi tigation for riparian vegetation removal from flood control maintenance (by Santa Cruz County Public Works Department) would require sufficient channel enlargement or levee construction so that the channel could accommodate peak flood flows without removing channel vegetation. The Santa Cruz County Public Works Department is urged to undertake such mitigation. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. CU4. SIGNIFICANT EFFECT: The potential for more frequent natural or artificial sandbar opening at the mouth of the Pajaro River may increase under the cumulative discharge for Alternative SL. This could result in potentially significant impacts to wetland habitat, fisheries, and wildlife (including rare, threatened, endangered, or species of special concern) in the pajaro River and Estuary. FINDSL1.DOC 01501-005 07/11/90 -26- '.... . . EXPLANATION OF MITIGATION OR AVOIDANCE: The frequency of sandbar breaching at the pajaro Lagoon shall be monitored prior to and after discharges from the wastewater treatment plant operation. If the frequency of sandbar breaching increases significantly from treatment plant discharges and adversely affects fish and wildlife habitat, then a culvert or pump will be installed. The installation of a culvert or pump will regulate water levels to prevent significant changes in salinity or temperature, which will reduce this impact to insignificance. FINDING: The project incorporates mitigation measures which avoid or substantially lessen the significant environmental effect thereof. CU5. SIGNIFICANT EFFECT: The secondary impacts of future growth in San Benito County and southern Santa Cruz County could result in increased runoff into pajaro River drainages, resulting in potentially significant impacts upon riparian vegetation (from channel scour, erosion, flood control measures, and pollution) EXPLANATION OF PARTIAL MITIGATION OR AVOIDANCE: The quantity and quality of runoff into the pajaro River could be controlled by implementation of local storm drainage standards requiring the construction of stormwater retention systems and the installation and maintenance of grease and sediment traps. As discussed in finding B12 above, the Cities are undertaking these mitigation measures for their own part, but cannot completely mitigate this cumulative effect by themselves. other public entities in which this growth may occur are urged to undertake similar mitigation measures to reduce the cumulative effect of urban runoff. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. CU6. SIGNIFICANT EFFECT: The project alternatives, combined with other proposed projects, would result in potentially significant cumulative impacts to regional air quality. EXPLANA'l'ION OF PARTIAL MITIGATION OR AVOIDANCE: The cumulative secondary air quality impacts resulting from growth- related emissions will be partially mitigated by policies and mitigations set forth within the transportation, land use, and/or air quality elements of the General Plans of Gilroy and Morgan Hill. These mitigation measures fall into two groups: transportation control measures and land use measures. Transportation control measures are strategies designed to reduce vehicle trips, shorten vehicle trips or shift trips to FINDSL1.DOC 01501-005 07/11/90 -27- . . nonautomobile modes. Land use measures attempt to develop a land form or land use mix that makes the transportation control measures more feasible or effective. The City of Gilroy is in the process of adopting an updated Circulation Element to its General Plan, which contains the goals of developing and maintaining a balanced transportation system. Specific policies to accomplish that goal are detailed in the Final EIR at page 3.5-15. The City of Gilroy is currently developing an Air Quality Element to its General Plan. This will include and perhaps strengthen the transportation and land use measures elsewhere in the Plan, and examine additional measures to reduce air quality degradation. The Morgan Hill General Plan also includes goals, policies, or actions in the Circulation and Land Use Elements that coincide with air quality planning goals. It is not possible to incorporate mitigation measures into this project to fully mitigate these cumulative secondary effects on air quality. In fact, the background emission levels are sufficiently high, even without contributions from Gilroy and Morgan Hill, that there would be exceedances of state and federal standards for air quality. The cities do urge other jurisdictions to adopt and enforce measures similar to those discussed above in order to attempt to mitigate these continuing cumulative air quality impacts. FINDING: The project incorporates mitigation measures which substantially lessen the significant environmental effect thereof. Complete mitigation cannot be implemented unilaterally by the cities because the potential impact occurs outside their jurisdiction and is within the control of other public agencies to mitigate. FINDSL1.DOC 01501-005 07/11/90 -28- . . 3. EVALUATION OF ALTERNATIVES: Because not all significant effects as discussed above can be eliminated or substantially lessened, this Council carefully evaluated several alternatives for an environmentally superior means of achieving the Project objective. Alternatives reviewed in addition to SL included L (land disposal), LD (land disposal with dewatering wells or underdrainage discharge to the Pajaro River) SO (surface discharge to the ocean), SP (surface discharge to the Paj aro River) and No Project. Based upon the Final EIR and other written and oral evidence in the record, the cities find that no alternative is environmentally superior. Each has significant unmitigatable effects. Alternatives L and SO have significant effects regarding geology; all alternatives but SO have significant effects with regard to water quality; all but the No Project alternative have significant effects with regard to biology and air quality; all but SP and No Project have significant effects on cultural resources; all alternatives have significant effects with regard to hydrology/water resources, odor, growth-induction impacts, public. services and utilities, and secondary effects from traffic and transportation. The evaluation of the alternatives was a long and complicated process that is difficult to summarize simply. However, the primary reasons for rejecting the other alternatives are as follows. Note that in the discussion below, all of the impacts due to the chosen alternative, SL, are not repeated either in the analysis of the SL alternative, nor in the analysis of the alternatives. Rather, the emphasis is on the relative differences among the alternatives. (A) SO Alternative (Surface Discharqe to the Ocean). Generally speaking the SO alternative had insignificant long-term environmental impacts, but had significant short-term environmental impacts primarily due to construction. These include: (1) Impacts on riparian vegetation and wildlife habit (all alignments), potentially significant loss of Watsonville Slough wetland vegetation (Alignments 1 and 2), significant disturbance of coastal beach and dune habitat (all alignments) and potentially significant displacement of coastal beach and dune habitat wildlife (all alignments). (2) Potential wildlife impacts on the Red-legged Frog, California Tiger Salamander, Yellow-bressted Chat, Yellow Warbler, smith's Blue Butterfly, rare and endangered plants, black legless lizard, Snowy Plover, Double-crested Cormorant, and Elegant Tern. (3) Disturbance of known cultural resource sites. FINDSL1.DOC 01501-005 07/11/90 -29- " . . Two long-term environmental impacts would be (1) potentially significant impact on fresh water riparian vegetation and wildlife and Steelhead migration as a result of eliminating seepage into Llagas Creek; and (2) the recharge into the upper semi-perched aquifer due to the transport of effluent to the Bay would be eliminated. One advantage of the SO alternative is the preservation of agricultural land, since additional land for percolation ponds is not necessary. Practical advantages of the SO alternative include (1) the lowest operating and maintenance costs; (2) the fact that regulations for ocean disposal are relatively well-defined; (3) the system would be relatively the most reliable of the alternatives. Practical difficulties with SO are: (1) it would be difficult to phase the system and to fund it because of the need to construct initially very extensive pipeline facilities; and (2) this alternative engendered the greatest political opposi tion; (3) uncertain impact of the federal Monterey Bay Sanctuary legislation; and (4) nonrestricted use of the effluent for reclamation would require further treatment. (B) SP Alternative (Surface discharqe to paiaro River) . The primary environmental advantage of the SP alternative is that it avoids the impacts on groundwater resulting from land disposal, and also avoids loss of agricultural land due to increased need for percolation ponds. It has generally similar impact as the SL alternative as regards impact on the pajaro River. However, a disadvantage of the SP alternative, as compared to SL, is its impact on the pajaro River during the low-flow summer months. Whereas the SL alternative would only discharge to the pajaro during the winter months, the SP alternative discharges year-round. The discharge during the summer would create potentially greater impacts due to elevated temperature of effluent (impact on Steelhead habitat and optimum growth and spawning), increased turbidity, and increased concentrations of copper. Alternative SL reduces these impacts considerably by using land disposal during the summer. Alternative SP also fails to diversify the disposal by not using any of the existing land disposal facilities. Like Alternative SO, it also removes significant recharge water from the upper semiperched aquifer. Practical advantage include: (1) a low capital cost; (2) the fact that future expansion would require minimal facilities; and (3) the effluent would be compatible with all reclamation uses. Practical disadvantages include (1) the highest operating and maintenance costs of any of the alternatives; (2) discharge to rivers is heavily regulated, and it is anticipated that the Regional Water Quality Control Board would be reluctant to grant FINDSL1.DOC 01501-005 07/11/90 -30- . . a permit for year-round discharge; and (3) because the SP discharge requires that the wastewater receive tertiary treatment, this plant would be the least reliable of the alternatives, though it is still deemed to be highly reliable. (C) L Alternative (Land disposal). environmental advantages of the L alternative are: The primary (1) The avoidance of impacts to the Pajaro River and Monterey Bay hydrology and water quality; (2) Avoidance of impacts to Steelhead and other native fish in the pajaro River and estuary, as well as fish-eating wildlife; (3) Recharge of treated effluent to the deeper confined aquifer of the Llagas Subbasin could create beneficial impacts to groundwater supplies of the Llagas Subbasin (as well as possibly the Bolsa Subbasin). The primary environmental disadvantages of the land disposal alternative are: (1) The unmitigable impact on potable groundwater. This impact is much worse for the L alternative than for LD or SL because the L alternative would put effluent into the deep aquifer, which is an important source of domestic water. (2) Removal of some 1300 acres from agricultural use due to need for percolation ponds. (3) Potentially significant impacts on habitat of San Joaquin Kit Fox, Black-shouldered Kite, Northern Harrier, burrowing Owl, Yellow Warbler, and Yellow-breasted Chat. (4) Impact on known sites of cultural resources. (5) Impact to adjacent trees due to root saturation. (6) Greater risk of failure due to extreme weather conditions, though the system is still deemed reliable. The L alternative has practical advantages that include: (1) presently land disposal is the least regulated of the various disposal methods; and (2) the L alternative would be the fastest to implement. It has the practical disadvantages of: (1) the highest capital cost (primarily land acquisition); (2) future expansion would be limited by land availability; and (3) use of the effluent for nonrestricted reclamation would require further treatment. (D) LD Alternative (Land disposal with dewaterinq wells or underdrains discharqinq to paiaro River. This alternative features a secondary treatment plant with denitrification, and would dispose of treated effluent on approximately 600 acres of land. Underdrains would remove effluent from beneath the land disposal sites, and the drained effluent would be then treated to remove iron and discharged into the pajaro River. Because this alternative has certain features in common with each of the other alternatives (except SO), its FINDSL1.DOC 01501-005 07/11/90 -31- . . advantages and disadvantages are closely related to various advantages and disadvantages of the other alternatives. Thus, as compared to the land disposal alternative, it has generally the same impacts, but has less "land-related" impact because it uses only 600, instead of 1300, acres for land disposal. Furthermore, while it would have an impact by raising TDS levels in the upper, semi-perched aquifer, it would not impact the more important lower aquifer as would the L alternative. As compared to Alternative SL, it would have greater impacts on the land, since it requires more acreage for land disposal than SL. It would have generally similar impacts related to the pajaro River due to river discharge, but these impacts would be worse due to the possibility of discharge to the river during the low-flow summer months. Alternative LD has the practical advantages of: (1) the lowest capital and present worth costs; (2) an even funding pattern (i.e., it does not require as heavy front-end costs as either the SO or L alternatives); and (3) it does not export all effluent from the groundwater basin. It has the following practical disadvantages: (1) discharge to the river is heavily regulated, and the trend is towards stricter requirements; (2) expansion may be limited by land availability; and (3) nonrestricted use of reclamation would require additional treatment. (E) No proiect Alternative. As discussed in detail in the EIR, the no project alternative would not result in a complete lack of growth. On the contrary, there would be growth, and the sewage effluent produced by that growth could not be accommodated by the community sewage system. It would most likely be accommodated through dispersed package treatment plants and other methods that would be much less under the control of the cities than the proposed plant expansion. This would lead to significant adverse impacts which would be much more difficult to moni tor, detect, and prevent than would a planned expansion of the sewage capacity centralized into one well-run central facility. These impacts include hydrology/water resources, water quality of Llagas Groundwater Subbasin and Bolsa Groundwater Subbasin, odor, and growth-inducement. (F) Conclusion. The impacts of the SL alternative are discussed in great detail in the bulk of these findings. Benefits of SL, not discussed in these findings include the increased pajaro River streamflows, with resulting dilution of concentrations of certain chemicals already present therein, increased groundwater recharge in the Pajaro Valley, preservation of open space for land disposal sites, and reduction in loss of agricultural lands due to not needing as much land for percolation ponds as alternatives L or LD. Since effluent would FINDSL1.DOC 01501-005 07/11/90 -32- . . not be discharged to the pajaro year-round, the adverse impacts of LD and SP due to summer discharge would be avoided. The SL alternative has the practical advantages of: (1) low initial capital costs; (2) the ability to phase in the plant expansion as growth occurs; and (3) the fact that the tertiary- treated water is comopatible with all reclamation uses without further treatment. Disadvantages include: (1) high operating costs; (2) the fact that discharge to the river is heavily regulated and the trend is towards stricter regulation; and (3) the fact that the tertiary plant is the most complicated among the alternatives, and hence may be expected to be less reliable than a simpler plant, though the cities find that in absolute terms the reliability of the plant is very high. As discussed above, all of the alternatives do have certain adverse environmental affects. The cities find based upon the extensive analysis presented in the Final EIR, as well as the record of written and oral testimony presented to them, that there is no environmentally best alternative. Balancing these environmental effects with the economic, technical, and feasibility considerations of the various alternatives, the Council has determined that Alternative SL best suits their needs and those of the residents in the service area. FINDSL1.DOC 01501-005 07/11/90 -33- . . 4. STATEMENT OF OVERRIDING CONSIDERATIONS: Notwithstanding the existence of significant effects which cannot be mitigated to a less than significant level, the council hereby finds that the benefits of the proposed project outweigh the unavoidable adverse environmental effects, and therefore finds the adverse environmental effects to be acceptable. The council finds that each significant effect identified in the Final EIR as described in section 2 above is acceptable because mitigation measures have been required to reduce these effects whenever such mitigation methods were feasible, and, on balancing the benefits to be realized by approval of alternative SL as the Plan against the remaining environmental risks, the following economic, social and other considerations outweigh the effects of any impacts that cannot be fully mitigated or avoided and support approval of the project: The sewage treatment plant servicing the cities of Gilroy and Morgan Hill has nearly reached capacity. virtually all residential, commercial and industrial growth for the past few years has been very limited, and future growth will be severely curtailed unless additional sewage capacity is provided. The Regional Water Quality control Board, the permitting authority for the current sewage treatment plant, required the cities to submit a long term wastewater management report. Further expansion of the treatment plant must be consistent with said report. The alternatives discussed in the proposed Long Term Wastewater Management Plan satisfy that requirement. Santa Clara County has recognized the needs of the South County region to provide adequate wastewater treatment for the area by expansion of sewage capacity, and has so informed the cities. (See letter from supervisor Susanne wilson dated April 29, 1986). The State Department of Housing and Community Development also urged Gilroy by letter of February 3, 1986 to increase its sewage capacity in the near future so that residential construction can resume at a rate at least equal to regional share determinations. These concerns have only grown more pressing since 1986 while this matter has been tied up in litigation. The city of Gilroy's General Plan identifies a pattern of planned growth and provision of urban services which necessitate additional long term wastewater treatment capacity. In particular, the reasons which necessitate this additional capacity are detailed in the "Planning policies Regarding Wastewater Treatment Facilities" memo to the City Administrator from the Planning Department dated April 25, 1986. FINDSL1.DOC 01501-005 07/11/90 -34- . . The city of Morgan Hill is not only guided by the growth policies in its General Plan, but restricted by initiative Measure E controlling growth within the city until the year 2000. Yet the current sewage treatment capacity, virtually all of which has been allocated for the controlled growth in the two cities, does not meet the urban service requirements of the General Plan. Expansion of sewage treatment capacity, as directed by the Regional Water Quality Control Board, has been studied by Montgomery Eng ineers as consultants to the two cities, by the citizens Sewer Advisory Committee, by the Joint Powers Committee of the two City Councils, and by the city councils themselves. written and oral testimony documenting the need for expansion was introduced by numerous residents and community groups at the public hearings held to review the Plan alternatives in connection with the original proceedings in 1986. A long term wastewater management plan for expanded sewage capacity is needed to implement the planning policies of the two cities. The economic viability of the two communities is uncertain without the planned growth allocated by the General Plans. In certain of the preceding findings, the statement is made that the environmental risk or impact will be tolerated in view of the importance of planning for expansion of sewage capacity as outlined above. Briefly stated, the reasons for making this statement with respect to the specific findings is as follows: A. IMPACTS WHICH CANNOT BE FULLY MITIGATED BECAUSE THE APPROPRIATE MITIGATIONS ARE WITHIN THE CONTROL OF OTHER AGENCIES The first category of impacts that can not be fully mitigated by the cities are those where the appropriate mitigation measures are not within the jurisdiction of the cities to implement. This includes, for example, five of the six impacts identified above as cumulative impacts, because the cumulative impact arises from actions that are not under the control of the cities. The cities believe that most of these impacts can be fully mitigated by appropriate actions undertaken by the proper public entities; they are listed here in the interest of providing maximum public information. As to each of these impacts, the cities urge the appropriate jurisdictions to carry out feasible mitigation measures that are deemed appropriate to atttempt to fully mitigate these impacts. (a) Findinq W01 (Impact on Users of paiaro River Water For Domestic Purposes). Jurisdiction to mitigate this impact lies with' the County of San Benito Health Department. This impact can be tolerated also because it affects very few persons, and because the present usage of the pajaro River for drinking water purposes is not recommended, even though the tertiarily treated effluent from Alternative SL comes very close to actually meeting drinking water standards, and, in many respects, actually FINDSL1.DOC 01501-005 07/11/90 -35- . . improves the water quality of the water flowing now in the pajaro River. (b) Findinq AQ3 (Secondary impacts on air quality). The secondary air quality impacts resulting from growth-related emissions should be mitigated by policies and mitigations set forth within the transportation, land use, and/or air quality elements of the General Plans of Gilroy and Morgan Hill. These mitigation measures are discussed in greater detail in the discussion of impact AQ3 above. It is not possible to incorporate mitigation measures into this project to fully mitigate these secondary effects on air quality. In fact, the background emission levels are sufficiently high, even without contributions from Gilroy and Morgan Hill, that there would be exceedances of state and federal standards for air quality. The cities do urge other jurisdictions to adopt and enforce measures similar to those discussed above in order to attempt to mitigate these continuing air quality impacts. In view of the specific benefi ts of the proj ect, the remaining unmitigated impact is deemed acceptable. (c) Findinq GI3 (Housinq pressure on San Benito County). continued implementation of City policies for a balance between jobs and housing in Gilroy and Morgan Hill as described in mitigation measure GI2 above will minimize this effect. San Benito County and the cities of San Juan Bautista and Hollister have jurisdiction and control over housing growth within their boundaries to limit development. These jurisdictions are urged to control housing growth within their boundaries in order to prevent or limit the adverse environmental affects resulting therefrom by use of their general plans and appropriate growth control ordinances as necessary. (d) Findinq PS2 (Secondary demand for increased public services). To the extent that services are to be provided by the cities themselves, this impact will be mitigated by following existing development and General Plan policies. For example, new development occurring in the cities will be evaluated for effects on service providers and conditions of mitigation imposed as required on the development, including but not limited to, formation of assessment districts and imposition of development impact fees to finance expansion of services. New development in the unincorporated area is controlled by the County of Santa Clara and it is wi thin County jurisdiction and authority to similarly regulate such growth. Morgan Hill Unified School District and Gilroy Unified School District should consider methods to increase school capacity, including year- round school terms and double sessions, in addition to financing provided by the state funds or new development impact fees. (e) Findinq T1 (Traffic impacts due to qrowth). The cities can undertake certain steps to try to mitigate traffic impacts FINDSL1.DOC 01501-005 07/11/90 -36- . . due to growth, but the major projects are within the jurisdiction of CalTrans. The cities of Gilroy and Morgan Hill shall continue to plan and fund traffic improvements identified to accommodate growth pursuant to their General Plans. They shall monitor traffic growth as new developments are approved, and impose traffic mitigation measures if required to increase capacity along major routes in the cities to accommodate expansion of Highway 101 and state Route 152. CalTrans is currently planning the improvement of state Route 152 from two to four lanes between state Route 156 and Bell Station. Construction is scheduled to be completed by 1992. Caltrans plans to widen state Route 152 between state Route 156 and u. s. Highway 101 by the year 2000. Long-range plans also call for the widening of u.s. Highway 101 to eight lanes between state Route 152 and Bernal Road, and to six lanes between Gilroy and the San Benito County line to the south. These projects will be completed before the year 2000. (f) Findinq CU1 (Inorqanic salts (TDS) in upper aquifer due to cumulative discharges from all sources). As shown in Table 5.7 in the Final EIR, the TDS discharged by the treatment plant under Alternative SL is only about one-sixth of the total discharge of TDS to the upper semi-perched aquifer (the rest coming from other dischargers and, primarily, from the unsewered area). This cumulative impact can only be partially mitigated by actions undertaken by the cities. Further mitigation must come from permitting and enforcement actions by the Regional Water Control Board and the County Health Department regarding other dischargers contributing to the cumulative impact. This impact will be partially mitigated by the imposition of source controls for TDS removal and the other procedures described above. Full mitigation through TDS removal from the treated wastewater is not practical or feasible for this plant. See the extensive discussion under impact WQ2, above, for an explanation of the infeasibility of full mitigation through some form of desalinization. The removal of inorganic salts is not a standard sewage treatment process, and has serious environmental consequences associated with it, particularly involving the large amounts of energy required and the difficulty of disposing of the resulting brine. Such treatment of the effluent is not required by Basin Plan standards, nor is it expected to be required by the Regional Water Quality Control Board, which will set waste discharge requirements for the plant. The EIR does not speci- fically recommend treatment to meet Basin Plan groundwater objectives with respect to inorganic salts. Except for alterna- tives so (surface discharge to the ocean) & SP (surface discharge to the pajaro River), which raise other environmental issues, all other alternatives including the No project alternative have the same potential for groundwater quality deterioration. Therefore, in view of the cities' need for sewage capacity to support FINDSL1.DOC 01501-005 07/11/90 -37- . . existing and planned urban uses, the environmental risk will be tolerated as an acceptable level of impact. (g) Findinq CU2 (Cumulative water quality impact of seepaqe and discharqes of Copper into the paiaro River in the dry season) . As shown in the Final EIR, less than half of the expected cumulative quantity of copper seeping and/or being discharged into the pajaro River in the dry season will originate from the treatment plant. In order to reduce its contribution, pretreatment for copper and/or treatment of wastewater shall be undertaken to maintain concentrations in the river at or below current levels in the dry season. The Regional Water Quality control Board is also urged to adopt more stringent standards for other dischargers to reduce this cumulative potential impact to a level of insignificance. (h) Findinq CU3 (Cumulative impact to veqetation, fisheries and wildlife from pipeline construction and ongoinq flood control) . This cumulative impact arises not from the proj ect itself or from any secondary effects of the project, but primarily from ongoing flood control measures that may be undertaken by other public agencies (such as Santa Cruz County Public Works Department). Mitigation for the riparian impacts from construction of a pipeline to the pajaro River itself in connection with this project would be provided for by compliance with the California Department of Fish and Game permit requiring a minimum one to one (1:1) replacement (or greater) of impacted riparian habitat. Mitigation for riparian vegetation removal from flood control maintenance (by Santa Cruz County Public Works Department) would require sufficient channel enlargement or levee construction so that the channel could accommodate peak flood flows without removing channel vegetation. The cities urge other pUblic entities having jurisdiction to undertake flood control measures as appropriate in ways that result in minimum disruption to riparian habitat. If they do so, then the cumulative impact can be fully mitigated. Because the implementation of such mitigation measures is not under the control of the Cities, the Cities hereby find that the specific benefits of the project outweigh any remaining impact that may be caused by ongoing flood control efforts of other agencies. (i) Findinq CU5 (Impact on paiaro River from urban runoff from San Benito County and Santa Cruz County). Control of urban runoff in these areas is obviously not within the control of the cities. The quantity and quality of runoff into the Pajaro River could be controlled by implementation of local storm drainage standards requiring the construction of stormwater retention systems and the installation and maintenance of grease and sediment traps. As discussed in finding B12 above, the cities are undertaking these mitigation measures for their own part, but cannot completely mitigate this cumulative effect by themselves. other public entities in which this growth may occur are urged to FINDSL1.DOC 01501-005 07/11/90 -38- . . undertake similar mitigation measures to reduce the cumulative effect of urban runoff. (j) Findinq CU6 (Cumulative impacts on reqional air quality) . Cumulative secondary air quality impacts result, of course, not just from the secondary effects of the project, but also from the effects of all other sources in the air basin, of which Gilroy and Morgan Hill form only a relatively small part. As discussed above, the effects arising from Gilroy and Morgan Hill will be mitigated by policies and mitigations set forth within the transportation, land use, and/or air quality elements of the General Plans of Gilroy and Morgan Hill. These mitigation measures fall into two groups: transportation control measures and land use measures. Transportation control measures are strategies designed to reduce vehicle trips, shorten vehicle trips or shift trips to nonautomobile modes. Land use measures attempt to develop a land form or land use mix that makes the transportation control measures more feasible or effective. " The City of Gilroy is in the process of adopting an updated Circulation Element to its General Plan, which contains the goals of developing and maintaining a balanced transportation system. Specific policies to accomplish that goal are detailed in the Final EIR at page 3.5-15. The city of Gilroy is currently developing an Air Quality Element to its General Plan. This will include and perhaps strengthen the transportation and land use measures elsewhere in the Plan, and examine additional measures to reduce air quality degradation. The Morgan Hill General Plan also includes goals, policies, or actions in the Circulation and Land Use Elements that coincide with air quality planning goals. Because the major component of the cumulative air quality impact arises from sources external to Gilroy and Morgan Hill, it is not possible to incorporate mitigation measures into this project to fully mitigate these cumulative secondary effects on air quality. In fact, the background emission levels are SUfficiently high, even without contributions from Gilroy and Morgan Hill, that there would be exceedances of state and federal standards for air quality. The cities do urge other jurisdictions to adopt and enforce measures similar to those discussed above in order to attempt to mitigate these continuing cumulative air quality impacts. In light of the specific benefits of the project and the fact that primary responsibility for the mitigation for this effect really lies elsewhere, the Cities deem the impact to be acceptable. B. IMPACTS FOR WHICH COMPLETE MITIGATION OR AVOIDANCE IS INFEASIBLE. (k) Findinqs W02 (Inorqanic Salts (TDS) in upper aquifer). Although listed as a potentially significant environmental impact, the analysis as presented in the Final EIR and summarized FINDSL1.DOC 01501-005 07/11/90 -39- . . in these findings shows that the proposed alternative would in fact be consistent with discharge standards set by the Basin Plan. since the upper semi-perched aquifer of the Llagas Subbasin is not an important source of domestic water supply, the environmental risk is felt to be very small. Partial mitigation will be provided as follows: Local pretreatment ordinances will be expanded to include limits for TDS levels released into the wastewater system. These will include pretreatment limitations for TDS and water monitoring for water softener companies, as well as educational programs to inform the public of the TDS effects of using water softening equipment. For the reasons given in detail in the discussion of finding AQ2 above, the cities find that full mitigation through desalinization is not feasible. Balancing the small risk to the environment, the provision of partial mitigation, and the infeasibility of full mitigation, the cities believe that this impact is acceptable. (l) Finding W03 (Pollution Due to Accidental Discharqe or Seismic Event). The treatment plant will be designed and operated so that the risk of such an accidental discharge would be extremely low. Some risk is unavoidable, since it is impossible to design a perfect plant that will function under all conceivable circumstances, but this risk exists with any of the proposed alternatives, including the no project alternative. In view of the low risk and impossibility of prevention for any sewage treatment system, the cities find that the remaining environmental impact is acceptable. (m) Findinq LU2 (Conversion of Agricultural Land Due to Growth). This impact exists as a result of any development, and is consistent with the growth plans of the cities contained in their general plans and growth control ordinances. (n) Findinq B8 (Impact upon salt marsh of discharqe of fresh water effluent into the paiaro River). The only possible full mitigation for the fact that the discharged effluent will lower the salinity in the lagoon would be to increase the salinity of the effluent. This would cause even greater impacts upon the fresh water habitat of the pajaro River for the entire length of the river from the discharge point to the salt marsh lagoon. Because these impacts on water quality and fresh water biologic habitat would likely be more severe than the relatively limited impact that may be caused by the fresh water discharge upon the salt marshes, the cities find that such mitigation is not appropriate and is therefore infeasible. Thus, there is no practical and feasible full mitigation for impacts to salt marsh vegetation caused by changes in soil salinity (Although this impact may be reduced if it is decided to install an outlet culvert or pump that would allow salt water intrusion back into the marsh) . FINDSL1.DOC 01501-005 07/11/90 -40- . . The salt marsh vegetation and habitat is not unique, and the impact upon it from the discharge of the treated effluent is somewhat speculative. On the other hand, the impact from any potential mitigation that would increase the salinity of the effluent would be much more severe and definite upon the entire fresh water habitat of the pajaro River from the discharge point all the way downstream. In view of the speculative nature of the impact upon the salt marsh vegetation, and the clear environmental tradeoff that would ensue from lowering the salinity of the effluent, the cities regard this impact as acceptable, in light of the specific benefits of the project as detailed above. (0) Finding B11 (Loss of habitat for Black-shouldered Ki te, Northern Harrier, and Burrowing Owl from construction of land disposal sites). Some loss of habitat resulting from construction of the land disposal sites can not be mitigated, although Alternative SL has the benefit, as compared to alternatives Land LD, of requiring less acreage for land disposal sites, thereby lessening the loss of agricultural land as well as the potential impact to the three species of birds mentioned above. By its very nature, the construction of land disposal sites causes a change in some terrestrial habitats. Providing suitable replacement habitat would require alteration of other non-grassland habitat to adapt it for the three above species. This would diminish the habitat value of the replacement land and result in additional biological impacts. Replacement habitat could also be created by the conversion of existing urban land to grassland. However, due to the large amount of land required, the Cities find that this would be infeasible. In this instance, there is no reason to believe that the loss of this habitat will be critical to the survival of any of these bird species. In view of the economic, social and other benefits of this project, as well as the fact that these species of birds are not rare, endangered or threatened, this impact is deemed acceptable. In summary, the Council finds that alternative SL represents a viable, economically and environmentally feasible expansion program for sewage treatment which can be phased to accommodate the planned growth of the two cities. FINDSL1.DOC 01501-005 07/11/90 -41- . . '. PASSED AND ADOPTED this special meeting of the Gilroy called vote: 24th day of September , 1990, at a City Council by the following AYES: COUNCILMEMBERS: GAGE, HALE, KLOECKER, ~mSSALLEM, NELSON, VALDEZ and HUGHAN NOES: COUNCILMEMBERS: None ABSTAINING: COUNCILMEMBERS: None ABSENT: COUNCILMEMBERS: None FINDSL1.DOC 01501-005 07/11/90 -42- . . I, SUSANNE E. STEINMETZ, City Clerk of the City of Gilroy, do hereby certify that the attached Resolution No. 90-68 is an original resolution, duly adopted by the Council of the City of Gilroy at a special meeting of said Council held on the 24th day of September , 19~, at which meeting a quorum was present. IN WITNESS WHEREOF, I have hereunto set my hand and affixed the Official Seal of the City of Gilroy this 26th day of September (Seal)