UC Davis Campus Wastewater Treatment Plant Expansion

Transcription

1 Final Focused Tiered Environmental Impact Report UC Davis Campus Wastewater Treatment Plant Expansion State Clearinghouse SCH No # Prepared by: EDAW 2022 J Street Sacramento, CA November 14, 2005

2 Final Focused Tiered Environmental Impact Report UC Davis Campus Wastewater Treatment Plant Expansion SCH # State Clearinghouse No Prepared for: Office of Resource Management and Planning 376 Mrak Hall University of California One Shields Avenue Davis, CA Contact: A. Sidney England Director of Environmental Planning 530/ Prepared by: EDAW 2022 J Street Sacramento, CA Contact: Gary Jakobs, AICP 916/ November 14, 2005 P 4T041.01

3 Chapter/Section Table of Contents Page 1 Introduction Purpose of the Final EIR Summary of the Proposed Project Summary of Comments on the Draft EIR Final EIR Organization Comments and Responses to Comments List of Agencies and Individuals Commenting on the DEIR Responses to Comments Text Changes to the EIR Mitigation Monitoring and Reporting Program Tables Page 4-1 Mitigation Monitoring and Reporting Program for the UC Davis Campus Wastewater Treatment Plant Expansion Project Appendices A Court Recorder Report of the University of California, Davis Public Hearing for the Draft Environmental Impact Report on the Campus Wastewater Treatment Plant Expansion Campus WWTP Expansion Final EIR EDAW University of California, Davis i Table of Contents

4 1.1 PURPOSE OF THE FINAL EIR 1 INTRODUCTION This Final Focused Tiered Environmental Impact Report (FEIR) for the Campus Wastewater Treatment Plant (WWTP) Expansion project was prepared in accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and the University of California Procedures for Implementation of CEQA. After completion of the Focused Tiered Draft Environmental Impact Report (DEIR), the University of California at Davis (UC Davis or campus) consulted with and obtained comments from public agencies that have legal jurisdiction with respect to the proposed project, and provided the general public with opportunities to comment on the DEIR. The DEIR was circulated for a 45-day public and agency review period from October 8, 2004 to November 22, A public hearing was held for the project on November 1, 2004 at 7:00 p.m. in the UC Davis Memorial Union s East Conference Room. This FEIR responds to significant environmental issues raised during the review and consultation process. In addition, this FEIR includes the proposed Mitigation Monitoring and Reporting Program. The Campus WWTP Expansion project EIR consists of this FEIR and the DEIR, which was published on October 8, The DEIR hereby is incorporated by reference. Copies of the DEIR and FEIR are available during normal operating hours at the UC Davis Office of Resource Management and Planning, 376 Mrak Hall on the UC Davis campus and online at The DEIR includes extensive references to the 2003 UC Davis Long Range Development Plan (2003 LRDP) and the 2003 LRDP EIR. The 2003 LRDP is designed to accommodate projected campus population growth and facilities development through the academic year, and the 2003 LRDP EIR evaluated the environmental impacts of that growth and development. As allowed under Section of the CEQA Guidelines and as stated in the DEIR, UC Davis is incorporating by reference portions of the 2003 LRDP EIR (State Clearinghouse Number ). Copies of the 2003 LRDP, 2003 LRDP EIR, and all documents that revise and amend these documents are available at the locations listed above. As the public agency principally responsible for approving or carrying out the proposed project, the University of California is the Lead Agency under CEQA and is responsible for reviewing and certifying the adequacy of this EIR and approving the proposed project. Approval for this project has been delegated to the campus by The Regents of the University of California and the UC Davis Chancellor will consider approval of the project in Fall SUMMARY OF THE PROPOSED PROJECT The Campus WWTP is located on approximately 16.5 acres in the south campus area of the UC Davis campus in Solano County, California. The WWTP is located approximately 0.5 miles north of Putah Creek and approximately 0.5 miles south of Interstate 80. The WWTP provides tertiary wastewater treatment for the campus, and discharges treated effluent to Campus WWTP Expansion Final EIR EDAW University of California, Davis 1-1 Introduction

5 Putah Creek. The WWTP was constructed and became operational in March 2000, and was designed to accommodate projected campus wastewater inflows through It was constructed to allow for modular expansion to meet the needs of the campus over time. The proposed project would expand specific modular components of the WWTP to meet campus demands for treatment capacity anticipated through The wastewater treatment capacity of the existing WWTP facilities is 2.7 million gallons per day (mgd) for average dry weather flows (ADWF) and 6.3 mgd for peak hourly wet weather capacity. The existing rate of campus wastewater inflow to the plant averages 1.8 mgd ADWF (it has increased since publication of the DEIR in 2004). During peak wastewater inflow periods, many of the plant s individual unit processes currently operate at capacity or will operate at capacity by approximately Inflows that exceed the peak hourly capacity must be diverted to temporary storage until the peak flows subside, after which they are routed back into the treatment plant for processing. Under the proposed project, specific WWTP processes would be expanded to provide capacity for 3.8 mgd ADWF and additional peak hourly inflows anticipated through The WWTP expansion for the proposed project would improve treatment process reliability and the plant s ability to meet current and anticipated future effluent regulatory requirements. Most construction activities associated with the proposed project would occur within the boundaries of the existing WWTP site; however, the project would also increase the capacity of the central campus influent pump station, which is located adjacent to the Old Campus WWTP, in the southerly area of the main campus. The project would allow for an increase in the volume of treated effluent discharged to Putah Creek. See Chapter 3, Project Description, of the DEIR for a complete description of the proposed project. 1.3 SUMMARY OF COMMENTS ON THE DRAFT EIR Comments on the DEIR requested clarifications to and amplifications of the analysis contained within the DEIR. None of the comments resulted in a change to the significant impacts of the project, to proposed mitigation measures or alternatives, or to any of the conclusions contained within the DEIR. However, some text changes have been made as an initiative of the Campus. 1.4 FINAL EIR ORGANIZATION This FEIR for the proposed Campus WWTP Expansion project is organized as follows: Chapter 1 Introduction: This chapter describes the purpose of the FEIR and summarizes the proposed project. Chapter 2 Comments and Responses to Comments: This chapter contains a list of all agencies and persons who submitted comments on the DEIR during the review period, the comment letters received during the review period, and responses to the comments. EDAW Campus WWTP Expansion Final EIR Introduction 1-2 University of California, Davis

6 Chapter 3 Text Changes to the EIR: This chapter describes text changes made to the DEIR as an initiative of the Campus. The text changes discuss the feasibility of potential measures to reduce electric conductivity impacts related to water quality (DEIR impact and Mitigation Measure ), discuss modifications to an alternative considered and rejected as infeasible, in Chapter 6 of the DEIR, and also modify the analysis of Alternative 4, in Chapter 6 of the DEIR. None of these changes result in new or substantially increased environmental impacts compared with the analysis in the DEIR. Chapter 4 Mitigation Monitoring and Reporting Program: This chapter describes the actions that must take place to properly implement project-specific mitigation measures (which apply to the areas of hydrology and water quality, biology, and air quality), associated monitoring responsibilities, and the monitoring schedule. A Mitigation Monitoring Program is required for mitigation measures to be implemented as part of the proposed project. Campus WWTP Expansion Final EIR EDAW University of California, Davis 1-3 Introduction

7 2 COMMENTS AND RESPONSES TO COMMENTS The DEIR for the proposed project was circulated for a 45-day public and agency review from October 8, 2004 through November 22, A public hearing was held for the project on November 1, 2004 at 7:00 p.m. No agencies or members of the public attended and no comments were provided at the hearing. Four comment letters were received during the public and agency comment period on the Draft EIR. These letters and the transcript of the public hearing are included in this section. All agencies and individuals that commented on the Draft EIR are listed below. 2.1 LIST OF AGENCIES AND INDIVIDUALS COMMENTING ON THE DEIR Letter Date Agency/Individual A November 29, 2004 State of California Governor s Office of Planning and Research, State Clearinghouse and Planning Unit B November 24, 2004 U.S. Department of Commerce National Oceanic and Atmospheric Administration, National Marine Fisheries Service C November 1, 2004 California Regional Water Quality Control Board, Central Valley Region D November 22, 2004 Yolo County Environmental Health Division 2.3 RESPONSES TO COMMENTS Each comment letter is presented with brackets indicating how the letter has been divided into individual comments. Each comment is given a binomial, with the letter appearing first followed by the comment number. For example, comments in Letter C are numbered C-1, C-2, C-3, and so on. Immediately following the letter are responses, each with binomials that correspond to the bracketed comments. Some comments on the DEIR do not pertain to physical environmental issues. Responses to such comments, though not required under CEQA, are included to provide additional information. The phrase Comment Noted is used when the EIR authors wish to acknowledge a comment that does not directly pertain to the environmental issues analyzed in the EIR, does not ask a question about the EIR, or does not implicate an element of, or conclusions of, the EIR. The intent is to simply recognize the comment. Campus WWTP Expansion Final EIR EDAW University of California, Davis 2-1 Comments and Responses to Comments

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10 Response to Comment Letter A State of California Governor s Office of Planning and Research State Clearinghouse and Planning Unit A-1 Comment noted. This letter indicates that UC Davis has met the requirements with respect to the review of the Draft EIR for the Campus Wastewater Treatment Plant Expansion Project, UC Davis. EDAW Campus WWTP Expansion Final EIR Comments and Responses to Comments 2-4 University of California, Davis

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12 Response to Comment Letter B United Stated Department of Commerce National Oceanic and Atmospheric Administration, National Marine Fisheries Service B-1 Comment noted. This comment letter concurs with the analysis of potential environmental impact assessment and conclusions presented in the DEIR for the fisheries resources issues. EDAW Campus WWTP Expansion Final EIR Comments and Responses to Comments 2-6 University of California, Davis

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16 Response to Comment Letter C California Regional Water Quality Control Board Central Valley Region C-1 UC Davis is aware that the NPDES permit renewal process for expanded wastewater flows may require information to support the Regional Water Quality Control Board (RWQCB) determination that the proposed project would be consistent with the state anti-degradation policy (State Water Resources Control Board s Resolution No ). The University will submit a complete permit renewal application, including any required additional analysis in support of an anti-degradation analysis, following completion of the CEQA process. As described on pp through of the DEIR, a full anti-degradation analysis was not conducted for the EIR as it involves social and economic considerations. Pursuant to Section of the State CEQA Guidelines, social and economic effects are not to be treated as significant effects on the environment, but may be used to determine if a physical change would occur and its significance. This type of information was not needed to conclude where water quality effects would be significant. UC Davis will provide the RWQCB with social and economic information needed for the antidegradation analysis in its permit application. Nevertheless, Section 4.1 (Hydrology and Water Quality) of the DEIR utilized a massbalance water quality analysis (described on p ) to evaluate the potential for the proposed increased effluent discharge rate to substantially degrade receiving water quality and, therefore, to potentially be inconsistent with the state s anti-degradation policy. The analysis considered the magnitude, geographic scope, and frequency of projected changes in receiving water quality for those constituents that currently have the potential to exceed a regulatory effluent quality permit limit included in the NPDES permit including aluminum (Impact 4.1-1), ammonia (Impact 4.1-2), arsenic (Impact 4.1-3), copper (Impact 4.1-4), cyanide (Impact 4.1-5), dichloromethane (Impact 4.1-6), dioxin (Impact 4.1-7), iron (Impact 4.1-8), lead (Impact 4.1-9), mercury (Impact ), nitrate and nitrite (Impact ), ph (Impact ), phosphorus (Impact ), electrical conductivity (Impact ), coliform bacteria (Impact ), residual chlorine (Impact ), and turbidity (Impact ). The results of the massbalance analysis were used to generally assess whether projected changes in receiving water quality would be inconsistent with the state anti-degradation policies. As described in the EIR and summarized below in Response to Comment C-2, the massbalance analysis indicated that for those constituents that would exhibit an increase in receiving water concentration, the increases would be minor and would not be expected to exceed applicable water quality criteria. Receiving water concentrations for aluminum and turbidity would decrease compared to existing conditions because the effluent has lower concentrations than Putah Creek. Mitigation measures are included to reduce any and all potentially significant water quality impacts to a less-thansignificant level. EDAW Campus WWTP Expansion Final EIR Comments and Responses to Comments 2-10 University of California, Davis

17 C-2 The DEIR adequately discusses receiving water assimilative capacity to determine the likely water quality impacts of the proposed project to Putah Creek resources and beneficial uses. The University does not receive dilution credits based on the flow of Putah Creek; therefore, the compliance of projected receiving water quality conditions resulting from implementation of the proposed project were evaluated for compliance with applicable water quality criteria assuming that measured data for undiluted WWTP effluent would be representative of worst-case receiving water quality conditions. No dilution or dilution credits are assumed. As a result, the mass balance analysis used in Section 4.1 of the DEIR (Hydrology and Water Quality) and described above in Response to Comment C-1 was used simply as an investigative tool to evaluate incremental project-related changes to receiving water quality with representative data collected in UC Davis is aware that evaluation of dilution allowances and mixing zones can be extremely complex, should they be warranted. The mass-balance analysis was used to evaluate potential changes to receiving water quality for each constituent identified in the NPDES permit that was determined to have a reasonable potential to exceed applicable water quality criteria. The mass balance analysis used an assimilative capacity approach in that receiving water quality was estimated with measured data collected in 2002 for WWTP effluent samples, Putah Creek (ambient water quality) samples, and flow rates for the effluent and streamflow. The effects of the proposed project were evaluated by performing the mass-balance analysis with increased WWTP effluent flow rate. The results of the mass-balance analysis indicated that the proposed project would not adversely affect Putah Creek water quality under representative 2002 conditions, or that any adverse effects could be mitigated. The analysis assumed undiluted effluent as representative of worst-case receiving water quality conditions, which would only occur during severe drought in the Putah Creek watershed. Undiluted effluent was compared with applicable water quality standards. This approach reflects the worst case (and rare condition) of zero flow in Putah Creek. As identified in the DEIR (p ), the passage of the Putah Creek Accord requires considerably higher minimum instream flows in Putah Creek than has occurred in the past since the Solano Project became operational. Therefore, the likelihood of zero flow in Putah Creek at the point of the Campus WWTP discharge is considerably lower than prior to adoption of the Accord. For the majority of the constituents that were analyzed in the EIR, the drought conditions analysis indicated that receiving water concentrations would be in compliance with applicable regulatory criteria. However, identified copper and cyanide concentrations have the potential to exceed applicable water quality criteria and, thus could cause receiving water quality to also exceed the criteria during droughts. Because the drought scenario was evaluated with undiluted effluent concentrations, and because mitigation measures were identified in the DEIR for these constituents, the analysis of the project s impact analysis of undiluted effluent is highly conservative and meets CEQA requirements for an environmental impact analysis. Campus WWTP Expansion Final EIR EDAW University of California, Davis 2-11 Comments and Responses to Comments

18 C-3 Additive or synergistic toxicity is evaluated in Chapter 4.2, Impact , of the DEIR. The impact of the project is evaluated in two ways, a review of scientific literature and review of the WWTP whole effluent bioassay results. The literature review presented in the DEIR (refer to p ) indicates that EPA considers acute toxicity factors to be potentially additive, however, chronic toxicity is not considered additive. The literature findings indicate that interactive acute toxicity effects can occur when concentrations are significantly elevated; however, they are not expected to occur at the constituent concentrations that typically exist in the undiluted WWTP effluent and its receiving waters, downstream of the discharge. The toxicity bioassay test results for the Campus WWTP indicate that the toxicity in undiluted effluent has not been observed and rarely causes low-level effects such as reduced growth. Discharges from the WWTP under the project condition are not expected to cause receiving water toxicity, regardless of the available dilution from background Putah Creek streamflow. Any additive acute toxicity that may occur would occur at less-than-significant levels. C-4 Modifying the campus water supply to mitigate for potentially significant electrical conductivity (EC) impacts is addressed in the DEIR on pages and , under Mitigation Measure , Potential Mitigation Measures for Electrical Conductivity that were Considered but Rejected. As stated in the DEIR, existing UC Davis deep wells that provide municipal domestic water supply have EC concentrations that range from 500 to 700 µmhos/cm. In comparison, EC levels in wells in the intermediate and shallow aquifers (which provide landscape irrigation water) range from roughly 1,100 to 1,200 µmhos/cm. The existing domestic water wells draw from the aquifers in the area with the lowest available EC values; therefore, the development of new or different groundwater wells would not be expected to substantially reduce EC in the WWTP inflow wastewater. In addition, potential reductions in EC levels in the public water supply may be possible if alternative surface water supplies were developed; however, developing new surface water sources would cost over $100 million and would take 10 to 15 years to implement, contingent on numerous legal, financial, and environmental considerations (City of Davis 2002). Therefore, this mitigation measure would be infeasible. That stated, the University is actively pursuing programs that would reduce EC levels and is committed to meeting the applicable permit limitations. Please see Chapter 3. C-5 Trihalomethane formation potential in receiving water was not evaluated in the DEIR because the Campus WWTP employs ultra-violet (UV) light disinfection as a substitute for chlorination and dechlorination to minimize the use and release of chlorine (Impact of the DEIR). The monitoring data indicate that the total residual chlorine levels in the undiluted WWTP effluent are consistently less than the detection level of 0.02 mg/l. Chlorine is used only infrequently for equipment cleaning and disinfection operations. The existing WWTP management protocols minimize the use of chlorination and divert all cleaning rinsate back into the wastewater inflow so that it is routed through the full treatment processes before discharge. Consequently, the analysis presented in the DEIR indicates that because chlorine use is not a routine EDAW Campus WWTP Expansion Final EIR Comments and Responses to Comments 2-12 University of California, Davis

19 operation at the WWTP and procedures are in place to control its discharge to the environment, the project poses a low risk of chlorine discharge. Therefore, the lack of significant residual chlorine in the undiluted effluent, in combination with no detectable trihalomethanes in the effluent, is considered sufficiently protective against the formation of trihalomethanes. In addition, trihalomethanes have not been detected in the Campus WWTP effluent. Table of the DEIR presents constituents that are required to be monitored by the RWQCB, but that were undetected in the effluent in the years Dichlorobromomethane, as listed in Table 4.1-6, was not detected in the WWTP effluent, which confirms that the WWTP is not a direct source of trihalomethanes. The analysis in the DEIR is believed to be adequate. C-6 Comment noted. Please see the Mitigation Monitoring and Reporting Program contained in Section 3 of this FEIR, which sets forth the preferred method of implementation for mitigation measures that were identified in the DEIR to reduce the effects of significant impacts. This information will be submitted to the RWQCB for consideration in the NPDES permit renewal. Campus WWTP Expansion Final EIR EDAW University of California, Davis 2-13 Comments and Responses to Comments

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21 Response to Comment Letter D Yolo County Environmental Health Division D-1 Comment noted. As described on p. 81 of the UC Davis Campus WWTP Expansion Tiered Initial Study (May 2004) and the 2003 LRDP EIR (pp to of Volume 2), the Campus implements a pretreatment program to reduce pollutant concentrations and ensure compliance with the NPDES permit limits in the plant s Waste Discharge Requirements issued by the RWQCB. Aspects of the pretreatment program include monitoring, inspection, education, and enforcement. The campus pretreatment program is monitored and modified as necessary to respond to changes in permit limits and permit limit exceedances (2003 LRDP Mitigation Measures 4.8-4[a] and 4.8-4[b]). For example, as discussed in Mitigation Measure 4.1-5(b) in Section 4.1 Hydrology and Water Quality of the Focused Tiered Draft EIR, the campus may adjust the WWTP s pretreatment program and inspection of campus-wide facilities to help determine the source(s) of cyanide and to consistently comply with the California Toxics Rule (CTR) cyanide criterion. Campus WWTP Expansion Final EIR EDAW University of California, Davis 2-15 Comments and Responses to Comments

22 3 TEXT CHANGES TO THE EIR This chapter presents revisions made to the DEIR as an initiative of the Campus. These revisions consist of updates and new considerations as to feasibility related to mitigation measures for water quality impacts (specifically, related to electrical conductivity, EC) as discussed in Section 4.1 of the DEIR, a technical modification to mitigation measure to conform it to the NPDES permit conditions, and a minor modification to the discussion of Alternative 4 (Divert Additional WWTP Effluent to Evaporation Ponds) in Chapter 6, Alternatives. These revisions do not result in a change to the conclusions presented in the DEIR. No new significant information has been added and no new impacts have been identified. Changes to the text of the DEIR are shown either by a line through text that has been deleted or double-underlined text where new text has been inserted. The specific revisions to the DEIR are presented below. Page of the DEIR, beginning at the second paragraph, has been revised to conform the mitigation measure for cyanide to the NPDES permit, which requires compliance in both the permit and in downstream water quality. The measure has also been modified to correct how sampling will be conducted. The measure has also been modified to move the monitoring location from the R1 to the R2 station, which is downstream of the WWTP, so that cyanide in the effluent can be measured if it is present (sampling at the R1, upstream location, would not detect cyanide in the effluent, if present, once it is discharged to Putah Creek). Implement a phased evaluation/source control measure to address effluent cyanide levels. (a) Part A: Pursuant to When conducting monitoring per the NPDES permit requirements, if a sample exceeds the 4-day average limit, UC Davis will collect effluent grab samples on four consecutive days of effluent composite samples, rather than one grab sample, so that a true 4-day average cyanide concentration can be determined. Also UC Davis will collect grab samples on each day at the R2 (downstream) R1 (upstream) monitoring station and analyze for cyanide. Finally, the R2 R1 and effluent flows will be recorded for the same days. If this monitoring demonstrates that the chronic (4-day average) cyanide CTR objective is not exceeded within Putah Creek downstream of the WWTP more often than once in 3 years, no further efforts need be expended. Conversely, if If this monitoring indicates that the CTR chronic cyanide criterion is or has reasonable potential to be exceeded in the receiving water more often than once in 3 years, Part B of this mitigation shall be implemented. (b) Part B involves conducting an evaluation to determine the source(s) of the cyanide, and developing and implementing modifications to WWTP operations and facilities to consistently comply with the CTR cyanide criterion in the receiving water, where it applies. Measures may be required that could include adjusting the WWTP s industrial pretreatment program and inspection of Campus-wide facilities to reduce discharges. Campus WWTP Expansion Final EIR EDAW University of California, Davis 3-1 Text Changes to the EIR

23 Page of the DEIR, beginning at the forth paragraph, has been revised as follows to add new information regarding the effectiveness of a measure to help mitigate EC concentrations in treated effluent. < Source Control for Campus Cooling Towers and Other Discharges: UC Davis is currently evaluating potential modifications that could be implemented for cooling tower operations that would reduce concentrations and loading of high-ec blowdown water (Brown and Caldwell 2003). In addition, tthe investigation involves identifying the type and number of water softeners and other on-site water treatment devices, and the potential for providing on-site treatment for these potentially high-ec waste streams. A modification that is in advanced consideration for the expansion of the central heating and cooling plant is the installation of reverse osmosis (RO) units to replace existing water softeners and dealkalizers. Water softeners and dealkalizers are currently used across the campus for treatment of water used for heating, cooling, and other purposes (e.g., cage washers, and other industrial equipment). These devices require the addition of salt. In some instances, these devices can be replaced by RO units that do not require added salt. These conversion projects will decrease the net salt loading to the WWTP. Optimization of these salt load sources could reduce EC levels in the WWTP effluent, however, the anticipated EC reductions would not be sufficient to meet the current NPDES permit limits if the mitigation measure were implemented alone. Previous investigations of cooling tower blowdown discharges indicated that the complete elimination of these discharges would potentially reduce EC in WWTP effluent discharges by approximately 50 An analysis by UC Davis shows that eliminating existing water softeners and dealkalizers at the central heating and cooling plant, and replacing them with RO units, would reduce the salts flowing to the wastewater treatment plant to the degree that EC levels in treated effluent would be reduced by 133 µmhos/cm. After installation of these RO units, treated effluent would contain a calculated 981 µmhos/cm (Phillips, correspondence dated June 24, 2005), which still exceeds the permit limit of 900 µmhos/cm, but brings the effluent closer to the compliance level. Additional Ppotential EC reductions from changes in other water softening operations have not been investigated completely, but the volume of these discharges is estimated to be a small fraction of the existing salt load from other sources (i.e., primarily drinking water) and would only provide minor incremental reductions. While optimization of these salt load sources would reduce EC in the WWTP inflow wastewater, such source control would not be expected to sufficiently reduce EC (a reduction of 200 µmhos/cm would be needed) to levels that would comply with the permit limit. Page of the DEIR, beginning at the first full paragraph, has been revised as follows to reconsider the feasibility of RO treatment at the wastewater treatment plant, and to add an additional potential mitigation measure to reduce EC concentrations. EDAW Campus WWTP Expansion Final EIR Text Changes to the EIR 3-2 University of California, Davis

24 Potential Mitigation Measures for Electrical Conductivity that were Considered but Rejected Two measures that could potentially be used to reduce effluent EC levels, reverse osmosis technology and development of an alternative source water supply for the campus, were considered but rejected as not practicable for the University and not suitable for current conditions at the WWTP. < Reverse Osmosis Technology: The use of reverse osmosis technology is a potential alternative to the proposed project identified at length in Chapter 6, Alternatives, and rejected for further analyses as infeasible. However, when combined with other source control actions that reduce influent loading, the feasibility of using reverse osmosis to provide final treatment might become feasible.reverse osmosis could potentially be implemented to reduce EC in a portion of the effluent and blended with the remainder of the effluent to meet the 900 µmhos/cm permit limit. When combined with the reverse osmosis project being considered at the central heating and cooling plant, a relatively small amount of effluent (approximately 10 percent) would be required to be treated with reverse osmosis in order to meet the 900µmhos/cm permit limit. Reverse osmosis systems require additional pretreatment filtration to reduce suspended solids. The reverse osmosis process also creates concentrated saline brine. The quantity of brine typically constitutes from 10 to 20% of the original wastewater volume and would require disposal. Disposal of the high-salt content and large volume of brine produced by reverse osmosis is difficult because of potential environmental effects of the brine and high operating costs. However, because the amount of wastewater being treated would be limited, it may be feasible to construct and operate the system, as well as dispose of the brine off site (i.e., at a landfill after dewatering or at the publicly owned treatment works that that accepts high salt discharges). Reverse osmosis technology would also be substantially more costly to construct than the proposed project and, because of higher energy use with these systems and maintenance issues, would be substantially more costly to operate. In addition, all of the other treatment process improvements to influent headworks, oxidation ditch, clarifiers, and biosolids handling that are part of the proposed project still would be required. Therefore, this mitigation measure would be infeasible. < Dilution with Solano Project Water: UC Davis could use a portion of its existing water from the Solano Project (Lake Berryessa), which would allow for the blending of some amount of this higher quality water with treated effluent, in order to produce a combined load of less than 900 µmhos/cm. This could be accomplished either through providing a minimum flow in Putah Creek and establishment of a mixing zone, which would also require RWQCB agreement, or by adding a small amount of Solano Project water to the treatment process at the WWTP be extending the campus water system. It is estimated that 1,000 acre-feet per year of Solano Project water would be needed. This measure would require consideration of water rights; its feasibility is currently unknown. Campus WWTP Expansion Final EIR EDAW University of California, Davis 3-3 Text Changes to the EIR

25 Potential Mitigation Measures for Electrical Conductivity that was Considered but Rejected Alternative Source Water Supply: Changing or modifying the EC content of the wastewater inflow could reduce the resulting EC levels in WWTP effluent. UC Davis would reduce the amount of water use from groundwater wells with elevated EC levels, or work with the City of Davis to develop an alternative low-ec water supply. The City of Davis and UC Davis have conducted joint investigations into the potential overall improvements to water supply quality (West Yost and Associates [2002], Luhdorff & Scalmanini [2003]). As noted above, the UC Davis deep wells that provide municipal domestic water supply have existing EC concentrations that range from 500 to 700 µmhos/cm. In comparison, EC levels in wells in the intermediate and shallow aquifers (which provide landscape irrigation water) range from roughly 1,100 to 1,200 µmhos/cm. The existing domestic water wells draw from the aquifers in the area with the lowest available EC values. Therefore, optimization of these salt load sources through the development and use of different or new groundwater wells would not be expected to substantially reduce EC in the WWTP inflow wastewater. Potential reductions in EC levels in the public water supply may be possible if surface water supplies were developed; however, developing new surface water sources would cost over $100 million and would take 10 to 15 years to implement, contingent on numerous legal, financial, and environmental challenges (City of Davis 2002). Therefore, this mitigation measure would be infeasible. The fourth paragraph on page 6-3 through the first full paragraph on page 6-4 of the DEIR have been revised as follows to reflect the information described above with respect to reverse osmosis technology and feasibility. This technology is now considered potentially feasible, due in large part to the expected reduction in salts from the central heating and cooling plant. This results in the need to treat less effluent with reverse osmosis, and makes this technology more affordable and feasible ALTERNATIVE TREATMENT This alternative would involve upgrades to the existing WWTP facilities to provide additional wastewater treatment improvements and further reduce the concentrations of wastes in WWTP effluent. Because the existing WWTP produces high quality tertiary-treated effluent, alternatives for treatment were limited to those specific measures that would substantially reduce treated wastewater pollutants that are associated with potential adverse environmental impacts. Reverse osmosis (RO) treatment technology can reduce total dissolved solids (TDS) (sometimes measured as electrical conductivity or EC) and other contaminants in municipal wastewater and could be used to further reduce the concentrations of wastes in WWTP effluent. Thus, use of RO would substantially lessen EC concentrations and loading. Because UC Davis NPDES permit includes a Cease and Desist Order aimed at reducing EC, compliance with the NPDES permit would eliminate a significant impact of the project pertaining to compliance with waste discharge permit requirements. As noted in EDAW Campus WWTP Expansion Final EIR Text Changes to the EIR 3-4 University of California, Davis

26 Section 4.1, the impact pertaining to EC is primarily related to permit compliance, not to maintenance of the beneficial uses of Putah Creek. To comply with the permit, either the RWQCB would need to alter the permit conditions to allow for the current level of EC generation, or UC Davis would need to implement substantial changes to its treatment plant processes (see measures to mitigate Impact ). RO is one of the potential mitigation measures addressed in Impact , and it is also addressed here. RO technology consists of high-pressure pumps that force wastewater through permeable membranes that effectively filter out the majority of contaminants such as TDS, pathogens, organic matter, and dissolved ions. RO systems operate most effectively on wastewater that has passed through microfiltration to remove the majority of filterable solid material. Waste brine that cannot pass through the RO membranes must be further treated or disposed. The generation of brine in a RO systems typically ranges in volume from 10 to 20 percent of the original wastewater inflow volume. Therefore, RO systems require alternative disposal means for the relatively large volume of brine. The opportunities for brine disposal could include evaporation ponds, solar ponds coupled with power generation facilities, deep well injection, or pipeline/hauling of brine to an acceptable surface water disposal site such as an ocean disposal outfall. This alternative would meet project objectives. It would also reduce, to a less than significant level, the impacts of EC (i.e. meeting the terms to the current permit) on Putah Creek. However, the development of RO technology for the campus WWTP is considered infeasible because of the much higher costs than conventional treatment and indirect environmental impacts associated with brine waste disposal (because of additional land conversion to evaporation ponds and the construction of power generation facilities). Additional costs associated with the construction of an RO system that produces effluent that meets the NPDES permit limit are estimated at roughly $5.3 million dollars. The long-term operation and maintenance needs, such as periodic membrane replacement, also result in substantially higher operational costs, estimated to be $380,000 annually (Phillips pers. comm.), for RO systems compared to conventional systems. In addition, the high-capacity and hi-pressure pumping systems require much larger quantities of energy than conventional wastewater treatment methods. The third paragraph on page 6-15 of the DEIR has been revised as follows to correct an inaccurate description regarding the ability of this alternative to meet project objectives following implementation. Ability to Accomplish Project Objectives This alternative would attain three of the four identified all of the project objectives. It would provide sufficient treatment capacity to meet anticipated demands through 2013, would increase treatment plant reliability, would improve the plant s ability to meet current and anticipated regulatory requirements, and would allow for modular Campus WWTP Expansion Final EIR EDAW University of California, Davis 3-5 Text Changes to the EIR

27 expansion of the treatment plant. However, it would place the burden of meeting water quality regulatory requirements on the City of Davis. The City is currently evaluating its operations so it can meet its current regulatory requirements. Because of this, it is not known if this objective would be met. However, it would result in significant environmental impacts that would not occur with the project, while not substantially reducing environmental impacts to water quality. EDAW Campus WWTP Expansion Final EIR Text Changes to the EIR 3-6 University of California, Davis

28 4 MITIGATION MONITORING AND REPORTING PROGRAM CEQA requires that a Lead Agency establish a program to report on and monitor measures adopted as part of the environmental review process to mitigate or avoid significant effects on the environment. This Mitigation Monitoring and Reporting Program (MMRP) is designed to ensure that, if the proposed project is approved, the mitigation measures identified in the EIR will be implemented. Along with this project-specific MMRP, this project incorporates, as part of the proposed project, relevant mitigation measures from the 2003 LRDP EIR, which are modified pursuant to the previous MMRP adopted by the Regents as part of the 2003 LRDP on November 20, The MMRP for the Campus WWTP Expansion project, as set forth in Table 3-1, describes monitoring and reporting procedures, monitoring responsibilities, and monitoring schedules for the project-specific mitigation measures identified in the EIR. All monitoring actions, once completed, will be reported in writing to the UC Davis Office of Resource Management and Planning (ORMP), which will maintain mitigation monitoring records for the proposed project. The MMRP will be considered by the Chancellor of ORMP in conjunction with project review, and will be included as a condition of project approval. The components of the MMRP are addressed briefly below: < Project Specific Mitigation Measures: The project-specific mitigation measures provide mitigation for the project beyond the measures that will be implemented pursuant to the 2003 LRDP EIR. As indicated in Table 2-1 in Chapter 2 of the DEIR, these measures were identified to address potential effects in the resource areas of Hydrology and Water Quality, Biological Resources, and Air Quality. < Monitoring and Reporting Procedure: Identifies the action(s) that must be completed for the mitigation measure to be considered implemented. < Mitigation Timing: Identifies the timing for implementation of each action associated with the mitigation measure in order to effectively accomplish the intended outcome. < Monitoring Responsibilities: Identifies the UC Davis entity responsible for undertaking the required action and monitoring the mitigation measure. Campus WWTP Expansion Final EIR EDAW University of California, Davis 4-1 Mitigation Monitoring and Reporting Program

29 Table 4-1 Mitigation Monitoring and Reporting Program for the UC Davis Campus Wastewater Treatment Plant Expansion Project 4.1 Hydrology and Water Quality Project-Specific Mitigation Measures Monitoring and Reporting Procedure Mitigation Timing Monitoring Responsibility Implement a phased evaluation/source control measure to address effluent copper levels. UC Davis will continue to monitor effluent copper concentrations and evaluate whether the frequency and measured concentration (i.e., assuming it continues to be detected in the future) warrant further measures to control its discharge to Putah Creek. Should future monitoring indicate a continued reasonable potential to exceed regulatory thresholds, the likely feasible operational change would be to modify the frequency of influent and effluent monitoring to implement earlier detection and treatment process modifications Implement a phased evaluation/source control measure to address effluent cyanide levels. (a) Part A: Pursuant to the NPDES permit requirements, if a sample exceeds the 4-day average limit, UC Davis will collect effluent grab samples on four consecutive days so that a true 4-day average cyanide concentration can be determined. Also UC Davis will collect grab samples on each day at the R2 (downstream) monitoring station and analyze for cyanide. Finally, the R2 and effluent flows will be recorded for the same days. If this monitoring indicates that the CTR chronic cyanide criterion is or has reasonable potential to be exceeded in the receiving water more often than once in 3 years, Part B of this mitigation shall be implemented. (b) Part B involves conducting an evaluation to determine the source(s) of the cyanide, and developing and implementing modifications to WWTP operations and facilities to consistently comply with the CTR cyanide criterion in the receiving water, Monitor effluent discharge copper concentrations. Document monitoring and compliance record. If there is a reasonable potential for NPDES permit limits or local limits of the pretreatment program to be exceeded (or if they are exceeded), implement modifications to pretreatment program and treatment operations. Monitor effluent discharge cyanide concentrations by collecting four consecutive days of effluent composite samples and upstream grab samples on each of the four days. Document monitoring and compliance record. If there is a reasonable potential for NPDES permit limits local limits of the pretreatment program to be exceeded (or if they are exceeded), implement modifications to pretreatment program and treatment operations. Operation on a continual basis per the NPDES permit Operation on a continual basis per the NPDES permit Operations & Maintenance Operations & Maintenance EDAW Campus WWTP Expansion Final EIR Mitigation Monitoring and Reporting Program 4-2 University of California, Davis

30 Table 4-1 Mitigation Monitoring and Reporting Program for the UC Davis Campus Wastewater Treatment Plant Expansion Project Project-Specific Mitigation Measures Monitoring and Reporting Procedure Mitigation Timing Monitoring Responsibility where it applies. Measures may be required that could include adjusting the WWTP s industrial pretreatment program and inspection of Campus-wide facilities to reduce discharges Implement a phased evaluation/source control measure to address effluent dioxin levels. UC Davis will continue to monitor effluent concentrations of dioxin and evaluate whether the frequency and measured concentration (i.e., assuming they continue to be detected in the future) warrant further measures to control their discharge to Putah Creek. Should future monitoring indicate a reasonable potential for dioxins to exceed regulatory thresholds, the likely feasible operational change would be to include dioxins into the existing industrial pretreatment program for the WWTP The following mitigation measures have been identified to minimize and avoid the potential continued exceedances of the NPDES permit limit, should the change in the permit not be granted by the SWRCB. One, or a combination of more than one, of there measures may be implemented, as necessary. Divert All Effluent to the City of Davis: Diverting all of the campus WWTP effluent to the City of Davis (City) wastewater treatment facilities would cease all discharges to Putah Creek. By ceasing all discharges, the WWTP would no longer be governed by the NPDES permit and the associated effluent limitations. In turn, the UC Davis effluent would become part of the City s effluent and would therefore be subject to the permit limitations contained in the City s NPDES permit. Monitor effluent discharge dioxin concentrations. Document monitoring and compliance record. If there is a reasonable potential for NPDES permit limits to be exceeded (or if they are exceeded), implement modifications to pretreatment program and treatment operations. Design and implement a diversion plan to divert all of the campus WWTP effluent to the City of Davis. Obtain permits, construct, and monitor construction. Compliance with NPDES permit limitations by City of Davis is outside of UC Davis jurisdiction. Operation on a continual basis per the NPDES permit Following receipt of SWRCB decision on NPDES permit limits. Prior to construction, during construction, and operation. Operations & Maintenance Operations & Maintenance, Grounds Division, Architects & Engineers, Office of Resource Management and Planning, City of Davis Campus WWTP Expansion Final EIR EDAW University of California, Davis 4-3 Mitigation Monitoring and Reporting Program

31 Table 4-1 Mitigation Monitoring and Reporting Program for the UC Davis Campus Wastewater Treatment Plant Expansion Project Project-Specific Mitigation Measures Monitoring and Reporting Procedure Mitigation Timing Monitoring Responsibility Change in Surface Water Discharge Location: Moving the WWTP effluent discharge location from Putah Creek to the Sacramento River may allow for a modified effluent limit by obtaining a dilution credit for the discharge of its wastewater. Other dischargers on the Sacramento River receive dilution credits. For instance, the Sacramento Regional Wastewater Treatment Plant, which treats 155 mgd, has a 14:1 dilution credit. Because the WWTP effluent exceeds the permit limit by only 100 µmhos/cm on average, the dilution credit necessary would be fairly small and would be achievable given the size of the discharge in comparison to the flow of the Sacramento River. Discharge All Effluent to Evaporation Ponds: Instead of discharging the WWTP effluent to Putah Creek, large evaporation ponds could be constructed with sufficient storage capacity to provide complete evaporation of WWTP effluent during the dry season. Agricultural Reuse with Winter Storage in Lined Ponds: This scenario would be a variation of the evaporation ponds and would include substantial reuse of recycled water during the summer for irrigation of useable agricultural lands or urban landscape. The goal would be to beneficially recycle as much water as possible during the summer to reduce the overall area of ponds required for storage and evaporation. Design and implement a diversion plan to divert all of the campus WWTP effluent to discharge to the Sacramento River. Obtain permits, construct, monitor construction, and monitor discharge. Design, obtain permits, construct, and monitor construction of evaporation ponds. Discharge all effluent to evaporation ponds and monitor and document results. Design, obtain permits, construct, and monitor construction of evaporation ponds. Discharge all effluent to evaporation ponds and monitor and document results. Prior to construction, during construction, and operation. Prior to construction, during construction, and operation. Prior to construction, during construction, and operation. Reuse treated wastewater during the summer. Operations & Maintenance, Grounds Division, Architects & Engineers, Office of Resource Management and Planning Operations & Maintenance, Grounds Division, Architects & Engineers, Office of Resource Management and Planning Operations & Maintenance, Grounds Division, Architects & Engineers, Office of Resource Management and Planning EDAW Campus WWTP Expansion Final EIR Mitigation Monitoring and Reporting Program 4-4 University of California, Davis