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HomeMy WebLinkAbout1988-09-27; City Council; 9662; 2020 Facilities Plan and Phase IV ExpansionAB#_ MTG Q-77-RR DEPT._§ML BILLCIPCOF CARLSBAD - AGEN —l««e TITLE: CONSIDER APPROVAL OF ENCINA WPCF YEAR 2020 FACILITIES PLAN AND PHASE IV EXPANSION O | O RECOMMENDED ACTION: Staff recommends that Council adopt resolutions approving the Year 2020 Encina WPCF Facilities Plan and the Phase IV Project and authorize the filing of Notice of Determination. ft^ §£•- 353 ITEM EXPLANATION: Facility Plan The Year 2020 Facility Plan reviews facilities needs and evaluates various treatment technologies available to meet those needs through the year 2020. The resulting analysis has defined a Phase IV Project designed to process 36.0 million gallons per day (MGD) of liquid wastes with solids content equivalent to 38.0 MGD. The sewer outfall system has been designed to accommodate the 38.0 MGD, providing a balance with the Encina solids treatment capacity. The plan anticipates treating 36.0 MGD of flow at the Encina WPCF, 0.75 MGD flow at Leucadia's Gafner Water Reclamation Plant, and 1.25 at the Shadowridge Water Reclamation Facility. Solids from the reclamation plants would be treated at Encina. The proposed Phase IV Expansion will provide Carlsbad an additional 3.52 MGD of treatment capacity, raising the existing total capacity from 5.72 to 9.24 MGD. Staff projects that the 3.52 MGD will provide up to 10 years of capacity. The proposed expansion represents a compromise between agency projected needs and those presented by the SANDAG Series 7 Population Projections. Total basin population and demand factors are summarized on the attached Tables II1-2 and V-6. Alternatives The Facilities Plan evaluated five alternatives, as described in the attached Summary and Recommendation. Three alternatives were designed for full secondary treatment and two were evaluated as advanced primary under the 301(h) Waiver Program. The selected alternative extends the existing treatment methods at full secondary treatment. Elements of the selected S-l alternative are delineated on the attached Figure X-8. Outfall Capacity It should be pointed out that at the completion of the Phase IV expansion, the capacity constraints will exist in the ocean outfall. Phase IV incorporates the addition of two outfall pumps and extension of the outfall surge tower which are designed to increase the existing outfall capacity from 40 MGD to 65 MGD. Assuming a peaking factor of 2.13, the existing outfall will only accommodate 30.5 MGD of flow. To match the 38 MGD projected, it was necessary to provide flow storage facilities to store peak flows until outfall capacity is available. This "Equalization" storage was provided by construction of future aeration basins and secondary clarifiers (see Figure X-8). PAGE TWO OF ABI The Phase V Project will deal with additional construction of flow equalization facilities or construction of a parallel outfall. Given Carlsbad's requirement to maintain 5 years of capacity, planning for Phase V should begin as soon as Phase IV is under construction. The Year 2020 Facilities Plan fully documents all design assumption and costs involved in the proposed $49,000,000 project. The plan is available in the City Manager's office and has been distributed to the libraries for public review. Environmental Impacts An Environmental Impact Report has been prepared for the proposed Phase IV expansion. Leucadia County Water District acting as lead agency held numerous public meetings and hearings on the document. On August 11, 1988, the Leucadia Board certified the report as complete. The City of Carlsbad and the other Encina Agencies as the primary financial backers of the project are considered as "responsible agencies" under State Law. A responsible agency, prior to approval of a project, must review and consider the "findings" and give notice of its approval to the County Clerk. The attached resolutions certify to Council's review of the E.I.R., its findings and directs submittal of the Notice of the Determination of the Council's action. A summary of the E.I.R. findings are attached as Exhibit A to the approval resolutions. The final E.I.R. has been submitted to the Council under separate cover. The E.I.R. has identified two significant impacts that cannot be mitigated: sludge disposal and growth inducement. The report recognizes that increased flows will produce increased sludge whose disposal has not been fully resolved and will likely entail future environmental impacts of an undisclosed nature. The E.I.R. also stipulates that the proposed project will accommodate growth beyond the Year 2020 Series 7 SANDAG Population Projections. All other impacts are insignificant or mitigated by the project design. In approving the E.I.R., Council will be recognizing the Statement of Overriding Considerations dealing with sludge disposal and growth inducement. FISCAL IMPACT: The City will be required to make available to the EAA by March 31, 1989, $11,278,000 to fund its share of Phase IV Expansion. As reported by the Finance Director to the Council at its September 6, 1988 meeting, insufficient funds exist in the Sewer Construction Fund to provide for this obligation. It has been proposed that the City join with other Encina Agencies to seek bond financing to raise these funds. In the absence of bond financing, the City would have to dedicate all available Sewer Construction Funds and borrow an additional $4 to $5 million from other funds. This action would delay other sewer projects currently budgeted and impact other unspecified projects. PAGE THREE OF AB» °l (& (Q £b Delaying the Phase IV expansion could result in failure to meet Growth Management Standards, which would stop development and further retard City revenues. Staff continues to support bond financing for the City's share of the Phase IV expansion. EXHIBITS: 1. Table III-2 Sewer Service Area Population Projections. 2. Table V-6, EWPCF Average Daily Flow Projections Using Year 2010 Allocations (MGD). 3. Figure IV-3 Flow Schematic. 4. Figure X-8, Alternative S-l Phasing. 5. Chapter 11, Summary and Recommendations. 6. Resolution No. &fe- 363 approving Phase IV Project and causing Notice to be filed with County Clerk. 7. Resolution No. 88- £5 Y approving the EWPCF Year 2020 Facility Plan. 6. Notice of Determination. TABLE III-2 EWPCF FACILITY PLAN SEWER SERVICE AREA POPULATION PROJECTIONS Service Vista (1) Carlsbad Buena Vista (2) San Marcos (3) Leucadia Encinitas Totals SANDAG Series 7 1980 35,300 24,400 5,500 0 20,800 25,000 7,000 118,000 189,440 1990 54,900 56,500 15,900 3,000 45,000 48,000 8,300 231,600 - (1986) (4) Year 1995 57,400 69,000 22,800 6,100 52,500 61,000 8,900 277,700 263,630 2000 60,600 81,500 24,100 6,100 61,500 74,000 16,600 324,400 293,007 2010 68,100 106,500 29,100 6,100 84,500 92,000 20,200 406,500 353,277 (1) Includes portion of Oceanside served by Vista. (2) Portion of City of Vista within the Buena Sanitation District service area. (3) Includes projected CSUSD populations. (4) Actual 1986 population. No projections available for 1990. TABLE V-6 EWPCF FACILITY PLAN EWPCF AVERAGE DAILY FLOW PROJECTIONS USING YEAR 2010 ALLOCATIONS (MGD) Service Area Vista Carlsbad Buena Vista (1) San Marcos Leucadia Encinitas Totals 1990 5.62 5.65 0.93 0.30 4.50 4.05 1.24 22.29 1995 5.85 6.79 1.38 0.37 5.40 5.08 1.41 26.28 Year 2000 6.05 7.81 1.78 0.44 6.21 6.01 1.56 29.86 2005 6.24 8.73 2.15 0.50 6.94 6.85 1.70 33.11 2010 7.50 9.24 2.26 0.55 7.54 7.11 1.80 36.00 (1) Portion of Vista within Buena service area. BUENA OUTFALL METER X—+)(CARLSBAD OUTFALL METER (FUTURE) SAN MARCOS OUTFALL METER A|R ..„ AIR , TO SECONDARY TREATMENT TO OCEAN OUTFALL LEGEND WA8TEWATER SLUDGE RECYCLE FLOW SCHEMATIC FIGURE IV-3 •ENCINA WPCF FACILITY PLAN- CHAPTER II SUMMARY AND RECOMMENDATIONS SUMMARY SERVICE AREA. The Encina service area is located in the northwest portion of San Diego County, and covers approximately 120 square miles. The Encina Water Pollution Control Facility (EWPCF) serves the Cities of Carlsbad and Vista, the Buena Sanitation District, the San Marcos County Water District, the Leucadia County Water District, and the Encinitas Sanitary District. The facility is owned and operated through a joint powers agreement. Each member agency has projected wastewater flows to the Encina WPCF through the year 2010. The year 2010 total wastewater flow was estimated at 41.40 M6D. This flow would serve a population greater than projected by SANDAG Series 7. For this reason, about 87 percent of the agency requested flow, 36.0 MGD, will be used as the basis of facility sizing to better coincide with SANDAG projections. This flow would serve an estimated 355,000 people. Using a decreasing rate of increase model, the year 2015 and 2020 flows would be 38.04 MGD and 39.61 MGD, respectively. These projections have been used as the basis for establishing future facility needs. EXISTING FACILITIES. The EWPCF incorporates preliminary, primary, and secondary treatment processes. Solids removed during treatment, solids disposed of by septage haulers, and solids discharged from up- II-l \ stream reclamation plants are stabilized and dewatered. Currently, the sludge is hauled to a San Diego County landfill. The treated wastewater is disposed of through an ocean outfall to the Pacific Ocean. A portion of the flow is reclaimed and reused throughout the plant. Wastewater Treatment. The treatment facilities are well operated and maintained. They are capable of meeting the existing waiver treat- ment requirements or secondary treatment requirements. The nominal capacity of the plant is 22.5 million gallons per day (MGD). Most of the unit processes are capable of treating loadings beyond this rate. The capacity of individual units has been taken in account in projecting future needs. The peak hydraulic capacity of interconnecting channels and piping has been sized for a flow of at least 90 MGD. Sludge Disposal. The stabilized sludge is dewatered by belt pres- ses before disposal. The presses concentrate the sludge to about 16 percent solids by weight. This level exceeds State requirements of 15 percent for landfill disposal. However, a higher cake solids of 18 to 20 percent may be desireable once the preferred solids residual program is implemented. This program would minimize landfill disposal. The sludge would be composted, and the compost could be recycled as a soil amendment. A solids content of 16 precent could increase composting costs. The EWPCF staff is continuing evaluations in an attempt to achieve a higher cake with the existing equipment. Ocean Outfall. The ocean outfall extends 7,800 feet into the Pacific Ocean. The outfall discharges at a mean depth of 150 feet. The II-2 ultimate hydraulic capacity of the outfall is 65.0 MGD. A new outfall or effluent flow equalization would be required within the planning period. At highest recorded tide, 32.7 MGD of effluent from the EWPCF can flow by gravity into the outfall. At higher flow rates, the effluent is pumped. There are two pumps, each rated at 40.5 MGD. Allowing one unit as standby, an additional pump would be required in the near future. Cogeneration Facilities. The EWPCF incorporates both electrical and mechanical cogeneration. There are 3 engine-generators rated at 475 kilowatts each. They are fueled by natural gas purchased from the San Diego Gas and Electric Company (SDG&E). As dictated by air pollution control permits, only two units can. be operated at a time. In 1986, an average of 436,850 kilowatt hours (KWHR) per month of electricity was produced for use within the plant versus only 1,920 KWHR per month purchased from SDG&E. The average cost of production is estimated at $0.098 per KWHR including an allowance for facility replacement and $0.087 without the allowance. A detailed cost breakdown is shown in Chapter IV. The unit cost would decrease as the plant's electrical demand increases. The generators are currently operating at about 55 percent of capacity. If all power were purchased from SDG&E, the 1986 cost would have averaged $0.10 per KWHR. There are two engine driven blowers that comprise the mechanical cogeneration facilities. Each blower is rated at 10,000 cubic feet per minute. The air is required for the activated sludge process, grit II-3 ! chamber agitation, and channel agitation. The engines are fueled by digester gas, a product of the anaerobic digestion stabilization pro- ; cess. Only one engine may be operated at a time due to APCD permit limitations. In 1986, 173,000 cubic feet of digester gas was used on an average daily basis. At residential gas rates, the value of this resource is estimated at $190,000 per year. Heat is recovered from the engine jacket water and exhaust sys- tems. The recovered heat is used for two purposes; one to heat influent sludge to the anaerobic digesters and two, to heat and cool buildings. The use of this heat further offsets the need to purchase electricity and natural gas for space conditioning. Using the engines as a heat source, the need for hot water boilers is eliminated. WASTEWATER FLOWS AND LOADINGS. Wastewater flows and characteristic records have been analyzed for the past 5 years of record. Per capita flows and loadings, in conjunction with the operation of upstream re- clamation plants and septage haulers, have been determined. These were used to project future conditions. Wastewater Flows. The 1986 average daily flow rate to the EWPCF was 16.4 MGD. This represents 73 percent of the nominal plant capa- city. Upstream reclamation flows, which are discharged to the ocean outfall through the fail safe line, averaged 1.4 MGD. Overall Encina per capita flows have averaged between 94 and 102 gallons per capita per day. This includes the contribution from commercial and industrial users. The relative contribution from these II-4 V___ _y users would not be expected to change in the future. A per capita flow of 100 gallons per capita per day (gpcd), which is typical for other agencies, has been used to project future flows for all the agencies except the Buena Sanitation District and the City of Vista. The Buena Sanitation District has requested a future per capita rate of 137 gpcd. The increase is a result of a projected large proportional contribution from commercial/industrial dischargers. Vista requested a future per capita flow of 115 gpcd, based on General Plan land use designations. Taking into account the future operation of the reclamation plants, projected average daily flows to the EWPCF are: Year Flow (MGD) 2000 29.86 2010 36.00 2020 39.61 Bar screen, grit chamber, and outfall capacity is based on peak wet weather flow. A peaking factor of 2.0 for the EWPCF is recommended as a basis of scheduling improvements. This factor should be continually evaluated as major storm events occur. Peak outfall flows are projected to be: Year Flow (MGD) 2000 61.72 2010 74.00 2020 81.22 The flow includes the discharge from the upstream reclamation plants to the failsafe line. The flows from the Shadowridge and Gafner satellite plants are assumed to be equalized, thereby eliminating any need of a peaking factor from these sources. II-5 Wastewater Loadings. Loadings have been evaluated for biochemical oxygen demand (BOD) and suspended solids (SS). Sources include the normal wastewater contribution, septage, and the sludge produced at the upstream reclamation plants. The sludges removed are discharged back to the sewer for stabilization at the EWPCF. Per capita loadings of 0.17 and 0.18 pounds per capita per day for BOD and suspended solids respectively have been determined from histori- cal records. These values are similar to those reported for other agencies. They do not include septage or satellite sludge loadings. In 1986, septage represented 2 percent of the total BOD load and 6 percent of the total suspended solids load. The liquid volume of 11,000 gallons per day is not significant. Seventy percent of the septage comes from outside the service area. The sludges removed from the upstream satellite plants are returned to the sewer for stabilization and dewatering at the EWPCF. The charac- teristics of the sludges are similar to those removed at the EWPCF. Sludge from the upstream plants made up about 9 percent of the 1986 suspended solids loadings and 6 percent of the BOD loading. Future influent concentrations are expected to decrease somewhat as the relative contribution of high strength septage and reclamation solids decreases. WATER QUALITY AND EFFLUENT LIMITATIONS. The existing National Pollutant Discharge Elimination System permit limits, established joint- ly by the Environmental Protection Agency and Regional Water Quality II-6 Control Board, San Diego Region are based on the 1982 California State Water Quality Control Plan for Ocean Waters referred to as the Ocean Plan. The Ocean Plan requires 75 percent suspended solids removal and maintenance of the receiving water quality at levels needed to protect designated beneficial uses. The current permit was issued under Section 301(h) of the Federal Clean Water Act which provides for a waiver from secondary treatment. Secondary treatment would require at least 85 percent removal of BOD and suspended solids and that concentrations of either constituent not exceed 30 milligrams per liter. Five of the member agencies have adopted a policy to treat to the secondary treatment level once reasonable and reliable sludge disposal is available. The EWPCF has met all discharge requirements under the present permit except for one suspended solids violation in February 1986 during a storm event. This would not be expected to reoccur. The EWPCF is capable of meeting probable future discharge require- ments, assuming that the source control program will continue to maintain the low level of heavy metals and toxic compounds discharged into the collection system. However, due to the dynamic behavior of regulations, prediction of future numerical discharge requirements is very difficult. Present concerns regarding future discharge include required disinfection of treated effluent, and treatment of discharged volatile organic compounds from the treatment process. These and other changes in regulations could result in additional cost and land II-7 D-*••£- requirements. Additional treatment facilities would be needed beyond 22.5 MGD of flow. ALTERNATIVE ANALYSIS. Five alternatives were identified that would be capable of meeting discharge requirements at future flows. Three would meet secondary treatment requirements. Two were evaluated for achieving the existing waiver conditions. The alternatives have been designated as: Secondary Treatment Description • S-l Activated Sludge S-2 Series Trickling Filter/Activated Sludge S-3 Parallel Trickling Filter/Activated Sludge California Ocean Plan (Waiver) Description W-l Primary Treatment/Activated Sludge W-2 Advanced Primary/Activated Sludge Alternative S-l would consist of expanding the existing activated sludge process with similar units. Alternative S-2 would utilize bio- towers to reduce the BOD loading prior to final treatment in the acti- vated sludge process. The blotowers would offset aeration require- ments. The third Alternative S-3 would use biotowers in parallel with the existing activated sludge process. The biotowers would be sized to produce an effluent with the same quality as the activated sludge. For the waiver condition, Alternative W-l would consider operating the EWPCF in the mode as currently used. Only the preliminary, primary, 11-8 and solids handling units would need expansion. The existing activated sludge processes would be of adequate capacity to provide enough eff- luent to blend with primary effluent to meet 75 percent suspended solids removal through the year 2020. Alternative W-2 would use the addition of ferric chloride and polymer to the primary clarifiers. The chemical addition would enhance primary clarifier performance to produce an effluent meeting the waiver requirements. The activated sludge process would be operated as needed for on-site reuse or potential off-site reclamation. Comparative costs for the alternatives are summarized in Table II-l for year 2010. Total capital costs as well as annual capital, operation, and maintenance costs are shown. From a total annual cost standpoint, Alternatives S-l and W-l appear the best alternatives for the two treatment scenarios. They have other advantages as to: 1) compatibility with existing facilities; 2) site master planning; 3) aesthetics, and 4) ability to reclaim effluent for future potential off- site use. Cogeneration Facilities. The cogeneration facilities have been evaluated to identify the most effective means of operation to minimize energy costs. The evaluation considered modifying air pollution con- trols to use more digester gas in the engines. Proposed changes in SDG&E rate structures were considered. Sale of electricity, digester gas, and waste heat were evaluated. Continued use of the cogeneration facilities appears to be cost-effective when compared to purchase of 11-9 \ TABLE II-l EWPCF FACILITY PLAN ALTERNATIVE COST COMPARISON YEAR 2010 Alternative Secondary S-l S-2 S-3 Waive r W-l W-2 Estimated Project Cost ($) 33,724,000 45,035,000 34,453,000 13,101,000 13,468,000 Estimated Annual Capital Cost ($/Yr) 3,786,000 5,056,000 3,868,000 1,471,000 1,512,000 Comparative O&M Cost ($/Yr) 3,053,500 3,360,400 3,020,500 2,523,500 2,689,000 Total Annual Cost ($/Yr) 6,839,500 8,416,400 6,888,600 3,994,500 4,201,000 Relative Ranking 1 3 2 1 2 (1) ENRLA 5500 11-10 •- v\ electricity from SDG&E. The continued favorable natural gas rates as required by PURPA for cogeneration facilities has a bearing on the economics. New air pollution controls should be considered that would allow full use of digester gas in all of the engines. The EWPCF is expected to produce excess heat, recovered as hot water, from the cogeneration facility. It appears that it would be beneficial to use the hot water for heating and air conditioning at a future, contiguous private development. The heat could be sold at a favorable rate while providing a net income to the EWPCF. RECLAMATION. Four of the member agencies own satellite reclamation plants. They are: Owner Facility Capacity San Marcos County Water Meadowlark Water 2.0 MGD District Reclamation Plant Buena Sanitation District Shadowridge Water 1.25 MGD (planned) Reclamation Plant 1.00 MGD (presently) Leucadia County Water Gafner Water 0.75 MGD District Reclamation Plant City of Carlsbad Lake Calavera Hills Water 1.2 MGD Reclamation Plant A portion of the total effluent is reclaimed, and the remainder is disposed of through the fail safe line to the ocean outfall. The Lake Calavera Hills Plant is not currently in operation. Secondary effluent is reused within the EWPCF for odor scrubbers, general washdown, engine cooling water, and landscape irrigation. 11-11 Current use is 3.5 MGD. This is expected to increase to 4.4 MGD as additional facilities are constructed. The cost for disinfection, pumping, and facility replacement for on-site reuse is estimated to be $231 per million gallons. If potable water were used for the above purposes, costs would be about four times higher since potable water costs $1,070 per million gallons at present. Until recently, the JAC policy was that reclaimed effluent for uses offsite would be provided by one of the four existing satellite plants. For comparative purposes, the cost has been developed for a 2.0 MGD, tertiary reclamation plant at the EWPCF. The effluent would be acceptable for unrestricted reuse as defined by Title 22 of the Califor- nia Administrative Code. The cost, including capital and operation and maintenance has been estimated at $1,460 per million gallons to produce Title 22 quality water for unrestricted use. This does not include the cost for treatment to secondary, pump stations, distribution pipelines, or irrigation systems nor does it reflect the offsetting revenue if reclaimed water were sold to users. Compared to present potable water costs, additional reclamation is not currently cost-effective. This condition could be affected by the availability of future water supply in Southern California. Water supply limitations could favor increased wastewater reclamation in the future. RECOMMENDED PLAN. Five of the six member agencies have passed resolutions to return to full secondary treatment once permanent sludge disposal facilities are in place. For comparison two recommended plans 11-12 \ have been described, one for the waiver and one for secondary treatment. Each would be capable of treating flows through the year 2020. The 2020 facility needs are summarized below. Preliminary Treatment. Preliminary treatment needs would be iden- tical for the two effluent quality scenarios. One additional bar screen would be installed in the existing channel, and two additional grit chambers would need to be constructed. Primary Treatment. Six additional primary clarifiers would be needed for both scenarios* These would be located west of the existing units and would provide sufficient treatment capacity to ultimate year. Common wall construction would be utilized. For the waiver mode, no additional liquid treatment processes would be built. The existing activated sludge processes would be of sufficient capacity to provide an overall blended effluent meeting the waiver requirements. For secondary treatment, all of the primary effluent would be treated further by an expanded activated sludge process. Activated Sludge. For the waiver, about half of the primary ef- fluent would receive secondary treatment. The remaining primary ef- fluent and activated sludge effluent would be blended prior to dis- charge. The blend would meet the requirements of the California Ocean Plan. No expansion of the existing activated sludge processes would be needed, however, one additional DAF thickener is required to handle the increase in solids loading. 11-13 -W For secondary treatment, one aeration basin, a motor driven blower, four secondary clarifiers, and associated return and waste sludge pumps would be needed. Two dissolved air flotation thickeners would be con- structed in addition to the two existing tanks. The waste activated sludge would be thickened prior to digestion. Sludge Stabilization. Sludges removed from the primary clarifiers and dissolved air flotation thickener would be stabilized by anaerobic digesters. One additional digester would be needed for the waiver, and two new units would be needed for secondary treatment. The size should match existing Unit No. 4 built during Phase III. Sludge Dewatering. Digested sludge would be dewatered by belt filter presses then hauled to a landfill for disposal. Two additional belt presses would provide dewatering capacity for the nonwaiver condition, while one additional belt press would be needed for the waiver condition. The addition of the belt presses requires the expansion of the existing dewatering building. The expansion would provide room for a total of four future belt presses. Odor Control. Odor control facilities are provided for the screenings building, and dewatering building. With the addition of a future grit chamber and channels to the screenings building no additional odor control equipment is expected to be required. For the dewatering building expansion, additional odor scrubber facilities may be required. This would be verified pending planned improvements to the existing exhaust system. Odor control facilities would be master 11-14 '*"%, planned for the activated sludge process. They would be provided only if a definite need is demonstrated. Miscellaneous Facilities. In addition to the treatment facilities, the existing Operations Building would need to be expanded. The main- tenance storage building will need to be relocated or replaced when the second new digester is built under the secondary treatment scenario. Other improvements identified include programmable controller/computer improvements, air pollution control modifications to the existing co- generation engines. Ocean Outfall/Effluent Flow Equalization Storage. The ocean outfall capacity would be increased to 65.0 MGD by the addition of two effluent pumps and extension of the surge tower. Once peak flows approach the capacity of the existing outfall, effluent flow equalization or a second ocean outfall paralleling (at least in part) the first would be required. Additional effluent capacity is projected to be needed by the year 1994 at a peaking factor of 2.5. Using effluent equalization, a basin volume of 21 MGAL would be required for ultimate year, and would provide equalization for a peaking factor of 2.5. This peaking factor should be further refined through future storm monitoring and evaluations. During the interim period through to the year 2010, effluent equalization would be provided, assuming a 2.0 peaking factor, by the construction of an extra secondary clarifier and aeration basin beyond treatment needs. 11-15 Costs. Total project costs through the year 2020 are estimated to be: Unit I Treatment Unit J Ocean Outfall/ Equalization $41,975,000 $29,394,000 $22,295,000 $29,394,000 Total $71,369,000 $51,689,000 S-l, Secondary Treatment W-l, Waiver The costs are at today's level (ENRLA 5500) and include allowances for engineering and contingencies. For secondary treatment, the Unit I capital cost equates to $2.45 per gallon of capacity at the 2020 projec- ted flow. This is less than the Phase III/IIIA, Unit I cost of $2.75 per gallon. Phase III/IIIA costs were escalated to ENRLA 5500. Phase III/IIIA did include many facilities that would be large enough for the year 2020 flows. However, the value of 5 existing primary clarifiers and Digesters 1 through 3 was not included in the comparative figure. PHASING. The first phase of construction, Phase IV, would serve treatment needs through the year 2010 (36.0 MGD). At that time, the next phasing of unit processes, Phase V, would need to be constructed. Phase V would handle projected flows to at least the year 2020 (39.61 MGD). With the exception of the aeration basins and digesters sufficient treatment capacity would be provided during Phase V for the ultimate design flow (45 MGD). Phase IV would include the following major treatment units. 11-16 v> Needed Units in Each Alternative Phase IV Unit Process Waiver Secondary Bar Screen 1 1 Grit Chamber 1 1 Primary Clarifiers 4 4 Aeration Basins 0 1 Blower 0 1 Secondary Clarifiers 0 3 DAF Thickeners 0 1 Digester 1 2 Belt Presses 0 2 In addition, Phase IV would include two new effluent pumps extension of the surge tower, and provision for interim effluent flow equalization. Initially, flow equalization would be provided by construction of an additional fourth aeration basin and eighth secondary clarifier. These would serve as the needed equalization volume until needed for treatment after the year 2010. Dedicated equalization or a parallel outfall would then be needed. These additional interim equalization units are not included above. Estimated project costs for each scenario excluding permanent disposal facilities are: ; Phase IV I Waiver $24,035,000 Secondary $48,792,000 These include both Unit I and J and provide an allowance for engi- neering and contingencies. The costs have been escalated to the mid- point of construction. SCHEDULE. The Phase IV schedule would include separate design and construction contracts for the treatment plant and ocean outfall facility expansion, Units I and J, respectively. Key dates are: 11-17 jj. J Unit I Unit J Begin Design February 1988 September 1987 Advertise for Bids April 1989 June 1988 Begin Construction August 1989 September 1988 Complete Construction August 1991 August 1991 Planning for separate Phase V construction would not need to be started until 2007. Based on the schedule, a cash flow has been prepared for Phase IV. The projected costs, by fiscal year are given below: Combined Approx. Fiscal Year Phase IV % of Total 1987/88 904,000 2 1988/89 2,788,000 6 1989/90 20,858,000 43 1990/91 22,576,000 46 1991/92 1.666,000 3 Totals 48,792,000 100 Most of the capital would be required in fiscal years 1989/90 and 1990/91. The above cash flow is for secondary treatment, and the costs are escalated to midpoint of construction. COST ALLOCATION. Costs have been allocated among the member agencies. New ownership percentages have also been determined. The allocations have taken into account: 1) Existing ownership; 2) Year 2010 needs for both Units I and J; 3) Balancing of future needs to future ownership; 4) Reflection of projected solids loading from upstream reclamation plants; 11-18 \ and 5) Effective credits and buyins reflecting revised ownerships. The methodology establishes a system for future capacity and cost adjustments. Projected ownerships and costs are: Ownership Unit I Solids Unit I Liquid Agency Vista Carlsbad Leucadia San Marcos Buena Encinitas (%) 22.35 25.68 19.75 20.96 6.26 5.00 (MGD) 8.05 9.24 7.11 7.54 2.26 1.80 and Unit J (%) 21.05 24.19 20.78 19.74 9.53 4.71 (MGD) 8.05 9.24 7.86 7.54 3.51 .1.80 Cost ($1,000) ($) 5,020 11,278 12,898 11,902 6,147 1,547 (%) 10.29 23.11 26.44 24.39 12.60 3.17 Totals 100.00 36.0 100.00 38.0 48,792 100.00 It is anticipated that Encinitas' need will decrease once their General Plan is adopted. Actual cost by agency will be based on the final engineer's estimate following completion of Phase IV construction. RECOMMENDATIONS Existing Facilities 1) Further evaluate the effect of dewatered cake solids content on costs of the preferred solids disposal alternative. New belt presses capable of producing drier cake may be warranted. Replacement of existing presses may also be warranted. Flows and Loadings 2) Continue monitoring of the wet weather peaking factor to better define the timing of outfall facilities. A minimum peaking factor of 2.0 is recommended. 11-19 J o Water Quality and Effluent Limitations 3) Continue testing activated sludge effluent for both total and carbonaceous BOD. If secondary permit is issued, apply for a revision in the NPDES permit allowing nitrification inhibited BOD tests if nitrogenous oxygen demand results in total BOD values exceeding 30 mg/1. 4) Establish policy restricting the use of the EWPCF for disposal of wastewater as part of hazardous waste cleanups. Such disposal would be subject to the Resource Recovery and Conser- vation Act requirements if brought into the plant via truck or designated pipeline, and could impair the effluent and sludge quality for reclamation and resource recovery. 5) Maintain aggressive pretreatment program in service area. 6) Monitor regulations under review (Proposition 65, Ocean Plan, Air Quality) to identify early on additional facilities required. Energy Utilization 7) Modify the existing engine air pollution control devices to allow full digester gas utilization. This would probably be accomplished by demonstrating performance to the Air Pollution Control District initially on one engine. 8) Continue efforts with SDG&E and the Public Utilities Commission to assure that future utility rates are fair to the EWPCF. 9) Implement other energy utilization recommendations summarized in Chapter VII. Reclamation 10) Establish policy that would maintain the total dissolved solids of the EWPCF effluent at 1,000 mg/1 or less. This quality would allow for future offsite reclamation. 11) Continue existing on-site reclamation of secondary effluent. On-site reclamation is less costly as compared to purchased potable water. 12) Further review JAG policy as to the desireability and timing of providing reclamation treatment at the EWPCF for offsite uses in concert with the County Water Authority reclamation effort in the Encina service area. 11-20 Recommended Plan 13) Continue designing Phase IV, Unit J on an expedited schedule to assure that there is sufficient outfall pumping capacity in case there occurs at the same time a high tide and peak wet weather flow when one unit is down for maintenance. 14) Phase IV design, Unit I includes secondary treatment facilities. Actual construction would be dependent on the future discharge requirements (waiver versus secondary). 15) Undertake a comprehensive building program analysis to define the best use of the existing Operations Building and to ex- plore the need for a future Administration Building. This should be done as part of or prior to Phase IV design. Effluent Equalization 16) Continue evaluation of equalization as a cost-effective alternative to a new ocean outfall. 17) Work to limit future peaking factors to 2.0 by controlling sources of inflow. 18) Pursue the acquisition of off-site land in order to provide space for the master planned 21 MGAL total effluent equalization storage. 19) Construct the fourth aeration basin and the eighth secondary clarifier during the Phase IV expansion in order to utilize the excess treatment basins for equalization storage to postpone the requirement for a separate dedicated storage basin or second parallel outfall. 20) Construct fourth aeration basin and eighth secondary clarifier basins to operate on a gravity fill type mode. Septage 21) Evaluate fee structure to reflect solids management program costs. 11-21 J NOTICE OF DETERMINATION TO: Office of Planning and Research 1400 Tenth Street, Room 121 Sacramento, GA 95814 XX Qounty -Clerk County of San Diego 1600 Pacific Highway San Diego, CA 92101 FROM: (Public Agency) ...City of Carlsbad on behalf of Encina Hater Pollution Control Facility 6200 Avenida Encinas Carlsbad, CA 92009-0171 SUBJECT: Filing of Notice of Determination in compliance with Section 21108 or 21152 of the Public Resources Code. Encina Water Pollution Control Facility Expansion Project Title 88041308 Betty Meyer (619) 438-3941 State Clearinghouse Number (If Submitted to Clearinghouse) 6200 Avenida Encinas, Carlsbad, CA Contact Person Area Code/Number/Extension Project Location Expansion of existing wastewater treatment plant to meet planned growth in the Project Description Encina service area. City of CarlsbadThis is to advise that the (B_$6iX#$&M#X&# Responsible Agency) has approved the above described project on 9-27-88 and has made the follow- (Date) ing determinations regarding the above described project: 1. The project X will, will not have a significant effect on the environment. 2. X An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA. A Negative Declaration was prepared for this project pursuant to the provisions of CEQA. 3. Mitigation measures X were, were not made a condition of the ap- proval of the project. 4. A statement of Overriding Considerations _X_was, was not adopted for this project. This is to certify that the final EIR with coranents and responses and record of project approval is available to the General Public at: Encina WPCF, 6200 Avenida Encinas, Carlsbad, CA 92009 Date Received for Filing and Posting at OPR Signature (Public Agency)Title Revised March 1986 RESOLUTION NO. 88"- 35.>**r RESOLUTION OF THE CITY COUNCIL OF THE CITY OF CARLSBAD APPROVING THE PHASE IV PROJECT AND CAUSING NOTICE TO BE FILED WITH THE COUNTY CLERK WHEREAS, the City of Carlsbad is a party to a Joint Powers Agreement, commonly Known as the Basic Agreement for the ownership, operation and maintenance of'the Encina Joint Sewer System; and WHEREAS, there exists a need to increase the capacity of said Joint Sewer System to serve the future needs of inhabitants of the City of Carlsbad as well as the future inhabitants of the areas served with sewer service by the Leucadia County Water District, the City of Vista, the San Marcos County Water District, the Encinitas Sanitary District and the Buena Sanitation District; and WHEREAS, pursuant to the California Environmental Quality Act, the Leucadia County Water District has been, and still is, acting as the Lead Agency on behalf of the Encina Joint Powers for said Phase IV Project; and WHEREAS; on August 11, 1988, the said Leucadia County Water District completed the Environmental Impact Report process and certified said Report as complete, and WHEREAS, in considering and evaluating the said Environmental Impact Report, the Leucadia County Water District made certain findings as required by law, copies of which are attached hereto and incorporated herein by reference; and WHEREAS, the City of Carlsbad is a "responsible agency" as defined in Section 21069 of the California Public Resources Code; and WHEREAS, V«*ihe City of Carlsbad has renewed and considered the "findings' of the Final Environmental Impact Report and desires to approve the Phase IV Project and give notice of such approval to the County Clerk of the County of San Diego; and WHEREAS; the Joint Advisory Committee to the Encina Joint Powers has heretofore unanimously approved the Phase IV Project after considering the "findings" of the Environmental Impact Report caused to be prepared and certified by the Leucadia County Water District; and WHEREAS, upon completion thereof the Phase IV Project will increase the treatment capacity of the Encina Water Pollution Control Facility from 22.5 million gallons per day to 36.0 MGD liquid and 38.0 MGD solids by the year 2010. NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF CARLSBAD AS FOLLOWS: Section 1. The City of Carlsbad hereby approves and adopts the findings contained in Exhibit "A" attached hereto and incorporated herein by reference. Section 2. The City of Carlsbad hereby approves the Phase IV Project. Section 3. The officers and employees of the City of Carlsbad are hereby authorized and instructed to prepare or cause to be prepared a Notice to the County Clerk of the County of San Diego within five days after adoption of this resolution that the City of Carlsbad approves the Phase IV Project, and intends to carry out the Project together with the other five (5) member agencies of the Encina Joint Powers, that the Project will have a significant impact on the environment and that an Environmental impact Report fw the Project has been cer1s*£ied as complete by the Leucadia County Water District; and that said Environmental Impact report is available to the general public. PASSED, APPROVED, AND ADOPTED at a regular meeting of the City Council on the 27th day of September , 1988, by the following votes, to wit: AYES: 5 NOES: None „ ABSENT: „ None JLAUDE A.TLEWIS,Mayor ATTEST: ALETHA L. RAUTENKRANZ, City Clerk ^CANDIDATE FINDINGS AND STATEMENT OF OVERRIDING CONSIDERATION Encina Water Pollution Control Facility Expansion SCH No. 2304130$ The California Environmental Quality Act (CEQA) 'requires that no public agency shall approve or carry out a project for which a Final Environmental Impact Report (EIR) identifies one or more significant effects thereof, unless such public agency makes one or more of the following findings: (1) Changes or alterations have been required in, or incorporated into, such project which rrudgate or avoid the significant environmental effects thereof as identified in the completed environmental impact report (2) Such changes or alterations are within the responsibility and jurisdiction of another public agency, and such changes have been adopted by such other agency or can and should be adopted by such other agency. (3) Specific economic, social, or other considera- tions make infeasible the mitigation measures or project alternatives identified in the environmental impact report (Section 21081 of the California Environmental Quality Act) CEQA further requires that, where the decision of the public agency allows the occurrence of significant effects which are identified in the Final EIR but are not at least substantially mitigated, the agency shall state in writing the specific reasons to support its action based on the Final BIR and/or other information in the record (Section 15093 of the CEQA Guidelines).. -19-EXHIBIT A FINDINGS The following findings are made relative to the conclusions and recommendations of the Final EIR for the Encina Water Pollution Control Facility (EWPCF) expansion (SCH No. 87042206). These findings have been prepared pursuant to Section 21081 of the California Public Resources Code and Sections 15091 and 15093 of the California Administrative Code. A. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion, find that the following changes or alterations are being required in, or have been incorporated into the project, which mitigate or avoid the significant environmental effects identified in the EIR. Specifically: Land Use Impacts: The project site is designated for public utilities use in the City of Carlsbad General Plan, with wastewater treatment identified as the primary onsite use by virtue of a General Plan Amendment Because of this designation and the fact that all proposed expansion facilities would be within the existing EWPCF site, no significant land use impacts are expected as a result of the proposed project A number of offsite facilities are generally discussed in relation to the proposed project, including a new ocean outfall or flow equalization structure, and a sludge reuse/disposal facility. All of these facilities could potentially impact offsite land uses through construction and operation activities. Findings: The EWPCF will obtain and comply'with all pertinent federal, state, and local discretionary and non-discretionary permits associated with the proposed expansion. This will allow implementation of the proposed project without t significantly affecting land use designations or character in the project site vicinity. No offsite structures are specifically proposed for the current EWPCF expansion. Construction of a new ocean outfall, flow equalization structure, or sludge reuse/disposal facility would require the preparation of a site-specific -20- environmental analysis to identify potential impacts related to land use and other appropriate resource values. Ocean Water Quality and Oceanography Impacts: Both the proposed project and waiver scenario alternative would result in the increased discharge of effluent. On the basis of current monitoring data, however, it is not expected that this increased discharge would have significant impacts to ocean water quality in the zone of initial dilution (ZID), the accumulation of organic material, or the direction of deposition in the area of discharge. Increased discharge could affect the rate of deposition, although the interaction between flow rates, mass load, and currents will ultimately determine the potential for deposition. Bacterial loads in the discharged effluent would likely be maintained at existing levels or reduced slightly under full secondary treatment, due to the combined effects of higher treatment levels and increased effluent quantities. Under the waiver scenario, total bacterial content in the discharged effluent would increase due to higher flows. It is possible that there will be a minor but increased risk of permit exceedence for bacterial content in the discharged effluent, particularly during the winter months. The potential for viruses will increase due to population growth; however, the potential risk from this increase cannot be identified at the present time and with the existing monitoring program. There would be an increased potential for aerosol dispersion of viruses in the surf zone and nearshore zone; however, this mode of transmission is still under study and no conclusions should be drawn at the present time. Findings; Adherence to appropriate regulations and requirements would reduce impacts related to effluent discharge below levels of significance. This would include restrictions on the quality of both effluent (NPDES permit) and influent (source control program) associated with the EWPCF. Viruses will be removed to a degree in the secondary process but will not be removed completely. Existing data has not identified significant adverse effects associated with viral loading in -21- effluent discharge, although no regulatory standards have yet been developed and methodology is not well established. Marine Bioloyv Impacts: No significant impacts to the wide diversity of marine organisms and habitats in the area of discharge would be anticipated from either the proposed project or waiver scenario. Findings: The proposed project would increase both the total quantity of effluent discharge and the associated level of treatment, resulting in no significant impacts to the marine environment. The waiver scenario would increase the total quantity of pollutants emitted due to increased discharge volumes. This would not be expected to result in significant impacts to marine biological resources because of existing discharge quality and monitoring requirements. Public Health Jmpacty Neither the proposed project or the waiver scenario would be expected to result in significant impacts related to public health concerns, assuming pertinent regulatory guidelines are met. Findings; The proposed project would likely maintain or slightly reduce the existing levels of bacteria in the discharged effluent, due to increases in both treatment levels and discharge volumes. Bacterial discharge levels for the waiver scenario would increase somewhat because of greater effluent volumes, and would increase the potential for permit exceedence, especially during the winter months. Viral loading would likely increase under both the proposed project and waiver scenarios due to increased flows. No known specific regulatory guidelines exist for the determination of public health risks associated with viral loading, although existing data has not yielded any statistically significant evidence for increased health risks associated with viral loading from effluent discharge. -22- Sludye Disposal Impacts: Sludge production for the EWPCF is projected to increase significantly with flow rates under either the proposed project or waiver scenario. This increase will represent a significant impact due to the increasing restrictions on current disposal methods. Findings: Both interim and long-term potential sludge reuse/disposal methods have been identified and are currently under investigation. Agreement has been reached regarding interim (up to 5-year) use of stabilized sludge as fertilizer/soil amendment for agricultural operations. Both interim and long-term sludge reuse/disposal systems will require implementation during the life of the proposed Phase IV project to accommodate projected sludge quantities. The long-term project may generate a number of potential environmental impacts depending on the alternative method and site selected. It will be necessary, therefore, to conduct appropriate environmental and technical studies prior to implementation, and to generate site-specific mitigation measures as required. The long-term disposal of sludge generated at Encina remains a potentially significant effect Energy Consumption and Conservation Impacts: No significant impacts are expected in regard to energy consumption and conservation for either the proposed project or waiver scenario. Findings: Expansion of the EWPCF would likely produce an operating energy deficit under either the proposed or waiver scenario. Increases in energy consumption would likely include additional requirements for electricity, natural gasi and diesel fuel (for hauling increased quantities of sludge). Onsite energy needs would be met by purchasing electricity and natural gas from San Diego Gas and Electric at variable rates, depending on periods of use, etc. The project design incorporates a number of measures to maximize cogcneration and the potential sale of excess digester gas and waste heat to offsite users. Additional diesel fuel consumption related to sludge hauling is not considered significant due to the relatively low number of truck trips involved. -23- Construction-Related Impacts Impacts: Construction-related activities would be expected to produce adverse effects related to noise, air quality, and traffic under both the proposed project and the waiver scenario. These would be related to the operation of heavy equipment and associated vehicles, excavation and grading activities, and the generation of traffic due to importation of equipment, employee ingress-egress, etc. These potential impacts are not expected to be significant, however, due to existing regulatory requirements and guidelines, and the traffic capacities of local circulation systems. Findings: Although no significant construction-related impacts are anticipated, a number of adverse noise, air quality, and traffic effects are likely. Appropriate mitigation measures related to hours of operation, dust abatement, equipment maintenance and traffic control have been recommended to minimize adverse construction-related effects. Noise Impacts: No significant impacts are anticipated in relation to long-term operational noise levels for either the proposed project or waiver scenario. pndings: The nature of the proposed facilities and the ambient noise levels in the EWPCP vicinity are such that no significant increase in noise levels is anticipated This conclusion is based in field measurements of existing noise levels and estimation of noise generation for proposed facilities. LBC&CJ&: The proposed project would require the use of one additional engine blower and engine generator, which would result in exceedence of existing regulatory emission limits. Another potential concern is the release of volatile organic compounds through the aeration process. The potential for greater overall release of such compounds would occur with implementation of the proposed project, due to the increased volume of aeration. The issue of volatile organic compound release is currently being investigated by the State Water Resources -24- Control Board (SWRCB), although to date no regulatory requirements or recommendations have been issued. No significant impacts would result from implementation of the waiver scenario. Findings: A new Air Pollution Control District (APCD) permit (including additional air pollution emission controls) would be obtained during implementation of the proposed project. This would mitigate potential air quality impacts below levels of significance for the proposed project, with no mitigation measures required for the waiver scenario. The results of the SWRCB investigation on volatile organic compound release will be incorporated into the project design (as appropriate) when available. Odors Impacts: No significant impacts related to the generation of offrite odors would be anticipated from implementation of either the proposed project or waiver scenario. Findings; The proposed project design incorporates a number of measures to mitigate potential odor-related impacts, such as the expanded use of odor control covers, ducting, and scrubbing towers. Additionally, the EWPCF maintains an odor control program whereby public odor complaints are logged and investigated, with additional system modifications incorporated as appropriate. Traffic Impacts: No significant impacts related to traffic are expected from either the proposed project or waiver scenario. Findings: Expansion of the EWPCF under either the proposed or waiver scenario would not significantly increase long-term traffic generation within the project site and vicinity. Such traffic would be limited to ingress and egress associated with a small number of additional employees and a relatively few additional truck trips related to sludge removal. The existing local circulation system is adequate to accommodate this traffic without significant effects. -25- Geofechnical Impacts; Based on previous geotcchnical investigations of the site, no significant adverse impacts are anticipated, A number of offsite improvements have been discussed in relation to expanding the existing plant, including a sludge reuse/disposal site and a new ocean outfall or flow equalization structure. These facilities could involve significant geotechnical constraints and would require site-specific environmental analyses prior to implementation. Findings: The standards established for excavation, grading, and construction in the previous geotechnical investigations of the site will reduce potential impacts below levels of significance. If construction activities result in unexpected subsurface conditions or unmitigated geologic impacts, further geotechnical investigation would be conducted as required. All potential offsite development will be subject to site-specific geotechnical analysis prior to implementation. Such evaluations will be conducted by a qualified geotechnical consultant, with all identified mitigation measures included in the subsequent facilities design. HydrologyAyater Quality Impacts: The proposed expansion of the EWPCF would not be expected to produce any significant impacts to surface or groundwater hydrology under either the secondary treatment or waiver scenarios. Findings; Potential water quality impacts include the contamination of surface runoff into the flood control channel and the influx of reclaimed effluent into local groundwater tables. Regulatory requirements and protective measures contained in the project design (e,g., containment berms) are expected to reduce these potential impacts below levels of significance. -26- Biological Resources Impacts: Implementation of either the proposed or waiver scenario expansion would not be expected to result in significant impacts to terrestrial biological resources. Selection of future offsite facility locations, however, may require additional biological investigation. Findings: Previous investigation of the EWPCF site did not identify any sensitive biological resource values. The current filled and graded nature of the site likely precludes the occurrence of any significant terrestrial biological resources there. Cultural Resources Impacts: No significant impacts to cultural resources are expected from implementation of either the proposed project or waiver scenario. Offsite improvements, however, would require site-specific archaeological investigations to determine potential impacts. Findings: Previous cultural resource investigations and the disturbed nature of the site likely precludes the occurrence of any significant cultural resources there. Visual Resources Impacts: No significant impacts to visual resources are anticipated from either the proposed project or waiver scenario. This is due to the fact that all proposed structures would be similar to existing facilities, and would be contained within the existing site. Findings: Although no significant visual impacts are anticipated from the proposed or expansion scenarios, a number of mitigation measures have been recommended to minimize adverse visual effects. These include the use of additional landscaping and the submission of detailed landscape and grading plans with the City of Carlsbad Precise Development Plan application. -27- Growth Inducemen| Impacts; The proposed project would provide treatment capacity in excess (approximately 2 percent for Phase IV and 5 percent for Phase V) of demands associated with populations and flows projected from SANDAG Series 7 forecasts (although less than those projected as necessary by individual member agencies). Consequently, it is considered growth-inducing under strict interpretation of the definitions contained in CEQA and S ANDAG guidelines. findings: Much of the excess capacity associated with the proposed expansion is attributable to the modular design of the plant, in which individual facilities have inherent, fixed capacities. This makes it virtually impossible to match projected populations and flows exactly. The project design incorporates phasing schedules to coordinate facility use with demand as fully as possible. In addition, treatment capacity needs incorporate septage flows from outside the service areas and daytime flows from the proposed California State University at San Diego North County Campus (CSUSD), which are not reflected in SANDAG Series 7 figures. B. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion, find that no changes or alterations contained therein which mitigate on avoid significant environmental effects are within the responsibility and jurisdiction of another public agency. C. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final BIR and record for the EWPCF expansion, find that specific economic, social, or other considerations make infeasible the project alternatives identified in the Final EIR as outlined below: 1. No Project Under the no project alternative the EWPCF would remain in its present condition with no expansion of treatment capabilities. The capacity of the existing facilities would not change, and the overall plant capacity would remain at 22.5 millions gallons per day (MOD). Based on projected wastewater flow rates, this capacity would be exceeded prior to 1995. -28- While the no project alternative would eliminate the potential environmental impacts associated with the proposed plant expansion, it would not meet the stated objectives. The EWPCF sendee area would be faced with inadequate wastewater treatment capacity within five years, and a moratorium of new sew hookups would likely be imposed by the member agencies of the Encina Joint Powers. 2. Engineering Alternatives Five potential expansion alternatives were identified in the EWPCF facility plan, including three for secondary treatment and two for the waiver scenario. Of these, one alternative was selected as the proposed project for each treatment scenario, with the remaining three designated as engineering alternatives as described below. a. Full Biofilter Treatment The first engineering alternative would allow for secondary treatment by utilizing biofilters to treat all effluent before it enters the aeration basins. This would reduce loading rates to the basins and increase their capacity, although the resultant hydraulic retention times would still require construction of an additional aeration basin. The potential environmental impacts for this alternative would be similar to the proposed project with the exception of the 20-foot biotowers being more visible, producing 18 cubic yards per day less sludge, and requiring 3.4 percent less energy that the proposed facilities. These latter two reductions are not considered significant in relation to overall sludge production and energy use. Total annual expenditures for this alternative would exceed the proposed project by approximately $ 1,500,000 due to the distribution of capital costs over time. Therefore, while this alternative is capable of meeting the stated project objectives, it offers no significant reduction in environmental impacts and would result in a substantial increase in capital costs. b. Partial Biofilter Treatment This alternative would provide secondary treatment by utilizing biofilters in parallel with aeration basins. Existing aeration basins would treat effluent up to their nominal capacity, with a two-stage biofUter treating the remaining flow. Potential environmental impacts for this alternative would be similar to the proposed project with the exception of the biotowers being more visible, producing 22 cubic yards per day less sludge, and requiring 3.4 percent less energy than the proposed facilities. These -29- "^f^ ^w^reductions are not considered significant with respect to overall sludge production and energy use. Total annual expenditures for the alternative exceed those for the proposed project by approximately $50,000. Therefore, while this alternative is capable of meeting the project objectives, it offers no significant reduction in environmental impacts and would result in a slight increase in capital costs. C. Waiver Alternative Usinp Chemical Addition This alternative utilizes chemical additives to increase treatment levels such that all primary effluent (except that used for reclamation purposes) could be diverted directly to the ocean outfall. Potential environmental impacts associated with this alternative would be similar to the preferred waiver scenario, with the exception of requiring 12 percent less energy and producing approximately 4 cubic yards per day of additional sludge. Total annual costs for this alternative would exceed those for the proposed project by approximately $200,000. This alternative would be capable of meeting the project objectives with a significant reduction in energy demand, although it would increase sludge production and raise annual expenditures by approximately 5200,000. 3. Use of Satellite Treatment Facilities There are currently three operating satellite treatment plants in the EWPCF service area, with a fourth scheduled to come in line in the early 1990s. The combined ultimate capacity of all four plants is 5.2 MOD, with the ability to utilize this total dependent on market and environmental factors. Even with full satellite treatment capacity, however, the combined EWPCF/satellite capacity of 27.7 MOD would be exceeded prior to 1995. The use of satellite treatment plants therefore does not meet the project objectives of providing adequate treatment capacity through the year 2020 and is not considered a viable project alternative in and of itself. 4. Water Reclamation Effluent suitable for various reclamation uses is currently produced at the operating satellite treatments plants and the EWPCF. By treating more wastewater at the satellite plants, the capacity requirements for the EWPCF plant could be reduced. However, solids treatment capacity requirements would remain unchanged since all wastewater solids are treated at the EWPCF. Any use of reclaimed (and hence treated) -30- water from the satellite plants would reduce flows to the outfall. However, the capacity for failsafe disposal through the outfall would still be required pursuant to Regional Water Quality Control Board (RWQCB) requirements. Assuming full use and reclamation of satellite treatment capacity (5.2 MOD) and 2.0 MOD of offsite reclamation use from the EWPCF, available effluent reclamation in the EWPCF service area would total 7.2 MOD. Based on flow projections listed in the Final EIR, the existing EWPCF capacity would still be exceeded prior to the year 1995, even with maximum available reclamation use. Utilizing maximum reclamation would reduce total flow to the ocean outfall by 7.2 MOD, although outfall capacity needs would remain the same due to fail-safe discharge requirements. Thus, water reclamation in itself does not meet the project objectives and is not considered a viable stand-alone alternative to the proposed project. 5. Phasing Alternative, This alternative involves providing capacity to the year 2000 under the designation of Phase IV, with subsequent development to the year 2010 designated as Phase V. Potential environmental impacts associated with the phasing alternative would be similar to those for the proposed phasing scheme, as the ultimate level of development would be the same. By combining construction activities to the year 2010 into a single Phase IV project, the overall impact period associated with construction activities would be reduced. Short-term (Phase IV) capital costs are lower for the alternative phasing scheme as it involves less Phase IV construction. Overall costs for this alternative, however, would be approximately 3 percent higher due to the economics of conducting separate construction operations (i.e., Phase IV and V). Also, based on member agency growth forecasts, the Phase IV project capacity would be exceeded well before the year 2000. Thus, this alternative would provide the same overall capacity as the recommended project, although no technical, environmental, or economic benefits would result, a longer construction period would ensue, and the Phase V project could be required shortly after Phase IV is brought into service. -31- STATEMENT OF OVERRIDING CONSIDERATIONS The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion make the following statements of overriding considerations: Although the project would result in sludge disposal and growth-inducement impacts which are not fully mitigated, to the extent that these impacts would occur, specific beneficial economic and social effects associated with the project would override these impacts. Population within the service area is projected to increase from the current figure of 200,000 to at least 380,000 by the year 2020. With this assumption, the current capacity of the EWPCF will be exceeded around the year 1991. The proposed phased expansion is designed to provide full secondary treatment capacity for projected population in the EWPCF service area through the year 2020 (Phase IV would provide capacity through the year 2010; Phase V would provide capacity to the year 2020). This is seen as a public benefit. In lieu of expanding the EWPCF facility, the service area member agencies would be compelled to provide adequate treatment capacity by some additional means and/or limit service area growth to reflect existing capacity. The proposed expansion would also provide additional local employment during the construction period, incrementally increasing regional income and employment in the San Diego region. Therefore, the member agencies of the Encina Joint Powers find that the need to provide wastewater treatment capacity to meet projected population growth in the EWPCF service area overrides the impacts which would result from this project -32- RESOLUTION NO. RESOLUTION OF THE CITY COUNCIL OF THE CITY OF CARLSBAD APPROVING THE ENCINA WATER POLLUTION CONTROL FACILITY YEAR 2020 FACILITY PLAN WHEREAS, the City of Carlsbad is a party to a Joint Powers Agreement, commonly known as the Basic Agreement for the ownership, operation and maintenance of the Encina Joint Sewer System; and WHEREAS, prudent planning requires that the member agencies of the Encina Joint Powers establish, approve and adopt a plan for providing sewer service to and for certain areas within Northern San Diego County; and WHEREAS, such a plan has been developed up to the year 2020 based on SANDAG Series 7 projections; and WHEREAS, the Leucadia County Water District has acted as the Lead Agency in causing to be prepared and certified as complete the Environmental Impact Report for said Plan which is commonly known as the Encina Water Pollution Control Facility Year 2020 Facility Plan; and WHEREAS, said Plan includes expansion of the Encina Water Pollution Control Facility in two phases, namely Phase IV and Phase V, both of which Phases are included in the aforesaid Environmental Impact Report; and WHEREAS, pursuant to the California Environmental Quality Act, the Leucadia County Water District has been, and still is, acting as the Lead Agency on behalf of the Encina Joint Powers for said Year 2020 Facility Plan; and WHEREAS; on August 11, 1988, the said Leucadia County Water District completed the Environmental Impact Report process and certified said Report as complete, which Report is designated by the State of California as SCH NO. 88-041308, and WHEREAS, in considering and evaluating the said Environmental Impact Report, the Leucadia county Water District made certain findings as required by law, copies of which are attached hereto and incorporated herein by reference, and are hereby adopted and approved by the City of Carlsbad; WHEREAS, the City of Carlsbad is a "responsible agency" as defined in Section 21069 of the California Public Resources Code; and WHEREAS, the City of Carlsbad hereby desires to approves and adopt the Year 2020 Facility Plan and desires to give notice of such approval to the County Clerk of the County of San Diego; and WHEREAS, the City of Carlsbad has heretofore approved the Phase IV Project as included in the above mentioned Environmental Impact Report, and the Notice of Determination of the Encina Water Pollution Control Facility Expansion to be filed with the County Clerk of San Diego County may include include notice of approval of the Phase IV Project; WHEREAS; the Joint Advisory Committee to the Encina Joint Powers has heretofore unanimously approved the Year 2020 Facility Plan and the Phase IV Project ; and WHEREAS, upon completion of the Encina Water Pollution Control Facility Expansion, the treatment capacity will increase to 39.61 HGD liquid/ 41.61 MGD solids. NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OP THE CITY OF CARLSBAD AS FOLLOWS: Section ,1. The city of Carlsbad hereby approves and adopts the findings contained in Exhibit "A" attached hereto and incorporated herein by reference. Sectionn2« The City of Carlsbad hereby approves and adoptts the Encina Water Pollution Control Facility Year 2020 Facility Plan; and Section 3. The officers and employees the City of Carlsbad are hereby authorized and instructed to prepare or cause to be prepared a Notice to the County Clerk of the County of San Diego within five days after adoption of this resolution that the City of Carlsbad approves the Encina Water Pollution Control Facility Year 2020 Facility Plan which notice may be included with the notice that the City of Carlsbad has also approved the Phase IV Project and intends to carry out said Project together with the other five (5) member agencies of the Encina Joint Powers, that the Project will have a significant impact on the environment and that an Environmental Impact Report for the Project has been certified as complete by the Leucadia County Water District, and that said Environmental Impact report is available to the general public. PASSED, APPROVED, AND ADOPTED at a regular meeting of the City Council on the 27th day of September , 1988, by the following votes, to wit: AYES:5 NOES: None ABSENT: None ATTEST: ALETHA L. RAUTENKRANZ, City Mayor IDATE FINDINGS AND STATEMENT OF OVERRIDING CONSIDERATION Encina Water Pollution Control Facility Expansion SCHNo. 39041302 The California Environmental Quality Act (CEQA) 'requires that no public agency shall approve or carry out a project for which a Final Environmental Impact Report (EIR) identifies one or more significant effects thereof, unless such public agency makes one or more of the following findings: (1) Changes or alterations have been required in, or incorporated into, such project which mitigate or avoid the significant environmental effects thereof asidentified in the completed environmental impact report (2) Such changes or alterations are within the responsibility and jurisdiction of another public agency, and such changes have been adopted by such other agency or can and should be adopted by such other agency. (3) Specific economic, social, or other considera- tions make infeasible the mitigation measures or project alternatives identified in the environmental impact report (Section 21081 of the California Environmental Quality Act) CEQA further requires that, where the decision of the public agency allows the occurrence of significant effects which are identified in the Final EIR but are not at least substantially mitigated, the agency shall state in writing the specific reasons to support its action based on the Final BIR and/or other information in the record (Section 15093 of the CEQA Guidelines).. -19-EXHIBIT A FINDINGS The following findings are made relative to the conclusions and recommendations of the Final EIR for the Encina Water Pollution Control Facility (EWPCF) expansion (SCH No. 87042206). These findings have been prepared pursuant to Section 21081 of the California Public Resources Code and Sections 15091 and 15093 of the California Administrative Code, A. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion, find that the following changes or alterations are being required in, or have been incorporated into the project, which mitigate or avoid the significant environmental effects identified in the EIR. Specifically: Land Use Impacts; The project site is designated for public utilities use in the City of Carlsbad General Plan, with wastewater treatment identified as the primary onsite use by virtue of a General Plan Amendment Because of this designation and the fact that all proposed expansion facilities would be within the existing EWPCF site, no significant land use impacts are expected as a result of the proposed project A number of offsite facilities are generally discussed in relation to the proposed project, including a new ocean outfall or flow equalization structure, and a sludge reuse/disposal facility. All of these facilities could potentially impact offsite land uses through construction and operation activities. Findings: The EWPCF will obtain and comply'with all pertinent federal, state, and local discretionary and non-discretionary permits associated with the proposed expansion. This will allow implementation of the proposed project without significantly affecting land use designations or character in the project site vicinity. No offsite structures are specifically proposed for the current EWPCF expansion. Construction of a new ocean outfall, flow equalization structure, or sludge reuse/disposal facility would require the preparation of a site-specific -20- <•»*». environmental analysis to identify potential impacts related to land use and other appropriate resource values. Ocean Water Oyalitv and Oceanography Impacts: Both the proposed project and waiver scenario alternative would result in the increased discharge of effluent. On the basis of current monitoring data, however, it is not expected that this increased discharge would have significant impacts to ocean water quality in the zone of initial dilution (ZID), the accumulation of organic material, or the direction of deposition in the area of discharge. Increased discharge could affect the rate of deposition, although the interaction between flow rates, mass load, and currents will ultimately determine the potential for deposition. Bacterial loads in the discharged effluent would likely be maintained at existing levels or reduced slightly under full secondary treatment, due to the combined effects of higher treatment levels and increased effluent quantities. Under the waiver scenario, total bacterial content in the discharged effluent would increase due to higher flows. It is possible that there will be a minor but increased risk of permit exceedence for bacterial content in the discharged effluent, particularly during the winter months. The potential for viruses will increase due to population growth; however, the potential risk from this increase cannot be identified at the present time and with the existing monitoring program. There would be an increased potential for aerosol dispersion of viruses in the surf zone and nearshore zone; however, this mode of transmission is still under study and no conclusions should be drawn at the present time. Findings: Adherence to appropriate regulations and requirements would reduce impacts related to effluent discharge below levels of significance. This would include restrictions on the quality of both effluent (NPDES permit) and influent (source control program) associated with the EWPCF. Viruses will be removed to a degree in the secondary process but will not be removed completely. Existing data has not identified significant adverse effects associated with viral loading in -21- effluent discharge, although no regulatory standards have yet been developed and methodology is not well established. Marine Biology Impacts: No significant impacts to the wide diversity of marine organisms and habitats in the area of discharge would be anticipated from either the proposed project or waiver scenario. Findings: The proposed project would increase both the total quantity of effluent discharge and the associated level of treatment, resulting in no significant impacts to the marine environment. The waiver scenario would increase the total quantity of pollutants emitted due to increased discharge volumes. This would not be expected to result in significant impacts to marine biological resources because of existing discharge quality and monitoring requirements. Public Health Impacts; Neither the proposed project or the waiver scenario would be expected to result in significant impacts related to public health concerns, assuming pertinent regulatory guidelines are met. Findings: The proposed project would likely maintain or slightly reduce the existing levels of bacteria in the discharged effluent, due to increases in both treatment levels and discharge volumes. Bacterial discharge levels for the waiver scenario would increase somewhat because of greater effluent volumes, and would increase the potential for permit exceedence, especially during the winter months. Viral loading would likely increase under both the proposed project and waiver scenarios due to increased flows. No known specific regulatory guidelines exist for the determination of public health risks associated with viral loading, although existing data has not yielded any statistically significant evidence for increased health risks associated with viral loading from effluent discharge. -22- Sludge Disposal Impacts: Sludge production for the EWPCF is projected to increase significantly with flow rates under either the proposed project or waiver scenario. This increase will represent a significant impact duo to the increasing restrictions on current disposal methods. Findings: Both interim and long-term potential sludge reuse/disposal methods have been identified and are currently under investigation. Agreement has been reached regarding interim (up to 5-year) use of stabilized sludge as fertilizer/soil amendment for agricultural operations. Both interim and long-term sludge reuse/disposal systems will require implementation during the life of the proposed Phase IV project to accommodate projected sludge quantities. The long-term project may generate a number of potential environmental impacts depending on the alternative method and site selected. It will be necessary, therefore, to conduct appropriate environmental and technical studies prior to implementation, and to generate site-specific mitigation measures as required. The long-term disposal of sludge generated at Encina remains a potentially significant effect Enerpv Consumption and Conservation Impacts: No significant Impacts are expected in regard to energy consumption and conservation for either the proposed project or waiver scenario. Findings: Expansion of the EWPCF would likely produce an operating energy deficit under either the proposed or waiver scenario. Increases in energy consumption would likely include additional requirements for electricity, natural gas*, and diesel fuel (for hauling increased quantities of sludge). Onsite energy needs would be met by purchasing electricity and natural gas from San Diego Gas and Electric at variable rates, depending on periods of use, etc. The project design incorporates a number of measures to maximize cogeneration and the potential sale of excess digester gas and waste heat to offsite users. Additional diesel fuel consumption related to sludge hauling is not considered significant due to the relatively low number of truck trips involved. -23- Construction-Related Impacts Impacts: Construction-related activities would be expected to produce adverse effects related to noise, air quality, and traffic under both the proposed project and the waiver scenario. These would be related to the operation of heavy equipment and associated vehicles, excavation and grading activities, and the generation of traffic due to importation of equipment, employee ingress-egress, etc. These potential impacts are not expected to be significant, however, due to existing regulatory requirements and guidelines, and the traffic capacities of local circulation systems. Findings: Although no significant construction-related impacts are anticipated, a number of adverse noise, air quality, and traffic effects are likely. Appropriate mitigation measures related to hours of operation, dust abatement, equipment maintenance and traffic control have been recommended to minimize adverse construction-related effects. Noise Impacts: No significant impacts are anticipated in relation to long-term operational noise levels for either the proposed project or waiver scenario. findings: The nature of the proposed facilities and the ambient noise levels in the EWPCP vicinity are such that no significant increase in noise levels is anticipated. This conclusion is based in field measurements of existing noise levels and estimation of noise generation for proposed facilities. AirOuaHtv The proposed project would require the use of one additional engine blower and engine generator, which would result in exceedence of existing regulatory emission limits. Another potential concern is the release of volatile organic compounds through the aeration process. The potential for greater overall release of such compounds would occur with implementation of the proposed project, due to the increased volume of aeration. The issue of volatile organic compound release is currently being investigated by the State Water Resources -24- Control Board (SWRCB), although to date no regulatory requirements or recommendations have been issued. No significant impacts would result from implementation of the waiver scenario. Findings; A new Air Pollution Control District (APCD) permit (including additional air pollution emission controls) would be obtained during implementation of the proposed project. This would mitigate potential air quality impacts below levels of significance for the proposed project, with no mitigation measures required for the waiver scenario. The results of the SWRCB investigation on volatile organic compound release will be incorporated into the project design (as appropriate) when available. Odors Impacts: No significant impacts related to the generation of offsite odors would be anticipated from implementation of either the proposed project or waiver scenario. Findings; The proposed project design incorporates a number of measures to mitigate potential odor-related impacts, such as the expanded use of odor control covers, ducting, and scrubbing towers. Additionally, the EWPCF maintains an odor control program whereby public odor complaints are logged and investigated, with additional system modifications incorporated as appropriate. Traffic Impacts; No significant impacts related to traffic are expected from either the proposed project or waiver scenario. Findings: Expansion of the EWPCF under either the proposed or waiver scenario would not significantly increase long-term traffic generation within the project site and vicinity. Such traffic would be limited to ingress and egress associated with a small number of additional employees and a relatively few additional truck trips related to sludge removal. The existing local circulation system is adequate to accommodate this traffic without significant effects. -25- Geotechnical Impacts: Based on previous geotechnical investigations of the site, no significant adverse impacts are anticipated A number of offsite improvements have been discussed in relation to expanding the existing plant, including a sludge reuse/disposal site and a new ocean outfall or flow equalization structure. These facilities could involve significant geotechnical constraints and would require site-specific environmental analyses prior to implementation. Findings: The standards established for excavation, grading, and construction in the previous geotechnical investigations of the site will reduce potential impacts below levels of significance. If construction activities result in unexpected subsurface conditions or unmitigated geologic impacts, further geotechnical investigation would be conducted as required. All potential offsite development will be subject to site-specific geotechnical analysis prior to implementation. Such evaluations will be conducted by a qualified geotechnical consultant, with all identified mitigation measures included in the subsequent facilities design. Hydrolofv/Water Quality Impacts: The proposed expansion of the EWPCF would not be expected to produce any significant impacts to surface or groundwater hydrology under either the secondary treatment or waiver scenarios. Findings; Potential water quality impacts include the contamination of surface runoff into the flood control channel and the influx of reclaimed effluent into local groundwater tables. Regulatory requirements and protective measures contained in the project design (e.g., containment berms) are expected to reduce these potential impacts below levels of significance. -26- Biological Resources Impacts; Implementation of either the proposed or waiver scenario expansion would not be expected to result in significant impacts to terrestrial biological resources. Selection of future offsite facility locations, however, may require additional biological investigation. Findings: Previous investigation of the EWPCF site did not identify any sensitive biological resource values. The current rilled and graded nature of the site likely precludes the occurrence of any significant terrestrial biological resources there. Cultural Resources Impacts: No significant impacts to cultural resources are expected from implementation of either the proposed project or waiver scenario. Offsite improvements, however, would require site-specific archaeological investigations to determine potential impacts. Findings: Previous cultural resource investigations and the disturbed nature of the site likely precludes the occurrence of any significant cultural resources there, Visual Resources Impacts: No significant impacts to visual resources are anticipated from either the proposed project or waiver scenario. This is due to the fact that all proposed structures would be similar to existing facilities, and would be contained within the existing site. Findings: Although no significant visual impacts are anticipated from the proposed or expansion scenarios, a number of mitigation measures have been recommended to minimize adverse visual effects. These include the use of additional landscaping and the submission of detailed landscape and grading plans with the City of Carlsbad Precise Development Plan application. -27- Growth Inducement Impacts; The proposed project would provide treatment capacity in excess (approximately 2 percent for Phase IV and 5 percent for Phase V) of demands associated with populations and flows projected from SANDAG Series 7 forecasts (although less than those projected as necessary by individual member agencies). Consequently, it is considered growth-inducing under strict interpretation of the definitions contained in CEQA and SANDAG guidelines. Fjndings: Much of the excess capacity associated with the proposed expansion is attributable to the modular design of the plant, in which individual facilities have inherent, fixed capacities. This makes it virtually impossible to match projected populations and flows exactly. The project design incorporates phasing schedules to coordinate facility use with demand as fully as possible. In addition, treatment capacity needs incorporate septage flows from outside the service areas and daytime flows from the proposed California State University at San Diego North County Campus (CSUSD), which are not reflected in SANDAG Series 7 figures. B. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion, find that no changes or alterations contained therein which mitigate on avoid significant environmental effects are within the responsibility and jurisdiction of another public agency. C. The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion, find that specific economic, social, or other considerations make infeasible the project alternatives identified in die Final EIR as outlined below: 1. No Project Under the no project alternative the EWPCF would remain in its present condition with no expansion of treatment capabilities. The capacity of the existing facilities would not change, and the overall plant capacity would remain at 22.5 millions gallons per day (MOD). Based on projected wastewater flow rates, this capacity would be exceeded prior to 1995. -28- While the no project alternative would eliminate the potential environmental impacts associated with the proposed plant expansion, it would not meet the stated objectives. The EWPCF service area would be faced with inadequate wastewater treatment capacity within five years, and a moratorium of new sew hookups would likely be imposed by the member agencies of the Encina Joint Powers. 2. Engineering Alternatives Five potential expansion alternatives were identified in the EWPCF facility plan, including three for secondary treatment and two for the waiver scenario. Of these, one alternative was selected as the proposed project for each treatment scenario, with the remaining three designated as engineering alternatives as described below. a. Full Biofilter Treatment The first engineering alternative would allow for secondary treatment by utilizing biofilters to treat all effluent before it enters the aeration basins. This would reduce loading rates to the basins and increase their capacity, although the resultant hydraulic retention times would still require construction of an additional aeration basin. The potential environmental impacts for this alternative would be similar to the proposed project with the exception of the 20-foot biotowers being more visible, producing 18 cubic yards per day less sludge, and requiring 3.4 percent less energy that the proposed facilities. These latter two reductions are not considered significant in relation to overall sludge production and energy use. Total annual expenditures for this alternative would exceed the proposed project by approximately $1,500,000 due to the distribution of capital costs over time. Therefore, while this alternative is capable of meeting the stated project objectives, it offers no significant reduction in environmental impacts and would result in a substantial increase in capital costs. b. Partial Biofilter Treatment This alternative would provide secondary treatment by utilizing biofilters in parallel with aeration basins. Existing aeration basins would treat effluent up to their nominal capacity, with a two-stage biofilter treating the remaining flow. Potential environmental impacts for this alternative would be similar to the proposed project with the exception of the biotowers being more visible, producing 22 cubic yards per day less sludge, and requiring 3.4 percent less energy than the proposed facilities. These -29- reductions are not considered significant with respect to overall sludge production and energy use. Total annual expenditures for the alternative exceed those for the proposed project by approximately $50,000. Therefore, while this alternative is capable of meeting the project objectives, it offers no significant reduction in environmental impacts and would result in a slight increase in capital costs. c. Waiver Alternative Using Chemical Addition This alternative utilizes chemical additives to increase treatment levels such that all primary effluent (except that used for reclamation purposes) could be diverted directly to the ocean outfall. Potential environmental impacts associated with this alternative would be similar to the preferred waiver scenario, with the exception of requiring 12 percent less energy and producing approximately 4 cubic yards per day of additional sludge. Total annual costs for this alternative would exceed those for the proposed project by approximately $200,000. This alternative would be capable of meeting the project objectives with a significant reduction in energy demand, although it would increase sludge production and raise annual expenditures by approximately 5200,000. 3. Use of Satellite Treatment Facilities There are currently three operating satellite treatment plants in the EWPCF service area, with a fourth scheduled to come in line in the early 1990s. The combined ultimate capacity of all four plants is 5.2 MOD, with the ability to utilize this total dependent on market and environmental factors. Even with full satellite treatment capacity, however, the combined EWPCF/satellite capacity of 27.7 MOD would be exceeded prior to 1995, The use of satellite treatment plants therefore does not meet the project objectives of providing adequate treatment capacity through the year 2020 and is not considered a viable project alternative in and of itself. 4. Water Reclamatiqn Effluent suitable for various reclamation uses is currently produced at the operating satellite treatments plants and the EWPCF. By treating more wastewater at the satellite plants, the capacity requirements for the EWPCF plant could be reduced. However, solids treatment capacity requirements would remain unchanged since all wastewater solids are treated at the EWPCF. Any use of reclaimed (and hence treated) -30- water from the satellite plants would reduce flows to the outfall. However, the capacity for failsafe disposal through the outfall would still be required pursuant to Regional Water Quality Control Board (RWQCB) requirements. Assuming full use and reclamation of satellite treatment capacity (5.2 MOD) and 2.0 MOD of offsite reclamation use from the EWPCF, available effluent reclamation in the EWPCF service area would total 7.2 MOD. Based on flow projections listed in the Final EIR, the existing EWPCF capacity would still be exceeded prior to the year 1995, even with maximum available reclamation use. Utilizing maximum reclamation would reduce total flow to the ocean outfall by 7.2 MOD, although outfall capacity needs would remain the same due to fail-safe discharge requirements. Thus, water reclamation in itself does not meet the project objectives and is not considered a viable stand-alone alternative to the proposed project. 5. Phasing Alternative This alternative involves providing capacity to the year 2000 under the designation of Phase IV, with subsequent development to the year 2010 designated as Phase V. Potential environmental impacts associated with the phasing alternative would be similar to those for the proposed phasing scheme, as the ultimate level of development would be the same. By combining construction activities to the year 2010 into a single Phase IV project, the overall impact period associated with construction activities would be reduced. Short-term (Phase IV) capital costs are lower for the alternative phasing scheme as it involves less Phase IV construction. Overall costs for this alternative, however, would be approximately 3 percent higher due to the economics of conducting separate construction operations (i.e., Phase IV and V). Also, based on member agency growth forecasts, the Phase IV project capacity would be exceeded well before the year 2000. Thus, this alternative would provide the same overall capacity as the recommended project, although no technical, environmental, or economic benefits would result, a longer construction period would ensue, and the Phase V project could be required shortly after Phase IV is brought into service. -31- STATEMENT OF OVERRIDING CONSIDERATIONS The member agencies of the Encina Joint Powers, having reviewed and considered the information contained in the Final EIR and record for the EWPCF expansion make the following statements of overriding considerations: Although the project would result in sludge disposal and growth-inducement Impacts which are not fully mitigated, to the extent that these impacts would occur, specific beneficial economic and social effects associated with the project would override these impacts. Population within the service area is projected to increase from the current figure of 200,000 to at least 380,000 by the year 2020. With this assumption, the current capacity of the EWPCF will be exceeded around the year 1991. The proposed phased expansion is designed to provide full secondary treatment capacity for projected population in the EWPCF sendee area through the year 2020 (Phase IV would provide capacity through the year 2010; Phase V would provide capacity to the year 2020). This is seen as a public benefit. In lieu of expanding the EWPCF facility, the service area member agencies would be compelled to provide adequate treatment capacity by some additional means and/or limit service area growth to reflect existing capacity. The proposed expansion would also provide additional local employment during the construction period, incrementally increasing regional income and employment in the San Diego region. Therefore, the member agencies of the Encina Joint Powers find that the need to provide wastewater treatment capacity to meet projected population growth in the EWPCF service area overrides the impacts which would result from this project -32-