CHAPTER 3.0 PROJECT DESCRIPTION

Transcription

1 CHAPTER 3.0 PROJECT DESCRIPTION

2 CHAPTER 3 PROJECT DESCRIPTION 3.1 PROJECT ALTERNATIVES The LWRP 2020 Plan identifies four treatment and effluent management alternatives that meet the project objectives, accommodating the projected flow rate for Each alternative consists of treatment capacity expansion, enhanced agricultural and municipal reuse programs, effluent management capacity to eliminate overflows onto Rosamond Dry Lake, and continued maintenance of Piute Ponds and Apollo Park. The alternatives differ in the level of treatment provided and in the acreage needed for storage reservoirs and agricultural land. Table 3-1 summarizes the components of each alternative. Table 3-2 summarizes the existing and planned facilities needed to accommodate the projected flow rate for each alternative. The Draft EIR identified Alternative 1 as the recommended project. In response to comments received during the public review period, District No. 14 s Recommended Project is now Alternative 21. The facility upgrades and expansions will occur in two phases, Stage V and Stage VI, corresponding to the fifth and sixth upgrades since the LWRP was first put into service in Stage V will be fully implemented by 2008, and Stage VI will be fullyis anticipated to be implemented by 2014, provided the current wastewater flow projection holds. The components listed in Table 3-2 will be constructed during Stage V. Table 3-3 shows additional facilities planned for each stage and each alternative. Figure 3-1 identifies the proposed locations for new facilities identified in the LWRP 2020 Plan. The area shown in Figure 3-1 is referred to in this EIR as the overall assessment area encompassing the potential footprints for agriculture operations and storage reservoirs. Figures 3-2 and 3-3 provide the same project information superimposed on aerial photographs. 3.2 PROJECT COMPONENTS Treatment Facilities The proposed primary facilities for each alternative will include communitors, aerated grit channels, primary sedimentation tanks, anaerobic digesters, and sludge drying beds. The existing influent pump station will be abandoned in place and replaced. Most of the proposed facilities will be constructed within the existing LWRP footprint. However, up to 15 acres around the border of the property will have Final LWRP 2020 Plan EIR 3-1 May 2004

3 Table 3-1 Summary of Lancaster Water Reclamation Plant 2020 Plan Final Project Alternatives Alternative 1 Alternative 2 Alternative 3 Alternative 4 TREATMENT FACILITIES Primary Treatment Secondary Treatment Tertiary Treatment Existing 16 mgd 10 mgd Existing 16 mgd oxidation ponds 10 mgd CAS (note: requires 5 acres adjacent to the LWRP) 10 mgd (note: AVTTP decommissioned) EFFLUENT MANAGEMENT FACILITIES Agricultural Reuse/Land Application a City of Lancaster Municipal Reuse Storage Reservoirs Piute Ponds Apollo Park 4,170 acres agricultural reuse 1.5 mgd summer (0.45 mgd winter) Existing 160 acres 1,100 acres Maintain existing area Maintain existing flow Existing 16 mgd 10 mgd 26 mgd CAS (note: requires 15 acres adjacent to the LWRP) 26 mgd (note: AVTTP decommissioned) 4,650 acres agricultural reuse 1.5 mgd summer (0.45 mgd winter) Existing 160 acres 750 acres (note: existing 270 acres of oxidation ponds utilized for storage) Maintain existing area Maintain existing flow Existing 16 mgd 10 mgd Existing 16 mgd oxidation ponds 10 mgd CAS (note: requires 5 acres adjacent to the LWRP) 10 mgd (note: AVTTP decommissioned) 13,880 acres agricultural reuse and land application 1.5 mgd summer (0.45 mgd winter) None (note: existing 160 acres of reservoirs available as backup storage) Maintain existing area Maintain existing flow Existing 16 mgd 10 mgd 26 mgd CAS (note: requires 15 acres adjacent to the LWRP) 26 mgd (note: AVTTP decommissioned) 13,940 acres agricultural reuse and land application 1.5 mgd summer (0.45 mgd winter) None (note: 270 acres of oxidation ponds and 160 acres of reservoirs available as backup storage) Maintain existing area Maintain existing flow Maintains and/or Enhances Piute Ponds Yes Yes Yes Yes BIOSOLIDS HANDLING FACILITIES Anaerobic Sludge Digesters Sludge Drying Beds Existing 5 tanks 6 tanks Existing 12 beds 11 beds Existing 5 tanks 8 tanks Existing 12 beds 17 beds Existing 5 tanks 6 tanks Existing 12 beds 11 beds (a) Acquiring, or extending contract with, Nebeker Ranch would secure acres of the amount indicated. Existing 5 tanks 8 tanks Existing 12 beds 17 beds Final LWRP 2020 Plan EIR 3-2 May 2004

4 Table 3-2 Lancaster Water Reclamation Plant Design Criteria for Each Alternative to be Implemented in Stage V ITEM EXISTING ALT 1 ALT 2 ALT 3 ALT 4 INFLUENT ODOR CONTROL STATION Number of Bio-trickling Filter Towers Number of Recirculation Pumps INFLUENT PUMP STATION Number of Pumps None None (will be abandoned) 5 (new) 5 (new) 5 (new) 5 (new) COMMINUTORS Number AERATED GRIT CHANNELS Number PROCESS AIR STATION Number of Blowers PRIMARY SEDIMENTATION TANKS Number PRIMARY SLUDGE PUMPS Number PRIMARY SLUDGE GRINDERS Number DIGESTION TANKS Total Number of Digesters DIGESTED SLUDGE TRANSFER PUMPS Number FERROUS CHLORIDE SYSTEM Number of Pumps SLUDGE DRYING BEDS Number OXIDATION PONDS Number TERTIARY TREATMENT Number of Filters 3 (new) 7 (new) 3 (new) 7 (new) Number of Chlorination Tanks 2 (new) 4 (new) 2 (new) 4 (new) CAS FACILITIES Aeration Tanks None Sedimentation tanks None Dissolved Air Flotation (DAF) Tanks None Source: LWRP 2020 Plan Final LWRP 2020 Plan EIR 3-3 May 2004

5 Table 3-3 Lancaster Water Reclamation Plant Staging Criteria for Selected Components EXISTING STAGE V STAGE VI TERTIARY TREATMENT Alternative 1 Filters Backwash pumps Chlorine Contact Chlorination Stations Alternative 2 Filters Backwash pumps Chlorine Contact Chlorination Stations Alternative 3 Filters Backwash pumps Chlorine Contact Chlorination Stations Alternative 4 Filters Backwash pumps Chlorine Contact Chlorination Stations STORAGE RESERVOIRS Alternative Alternative Alternative Alternative AG. LAND PIPELINE & PUMPSTATIONS Alternatives Pipelines (Alts 1 and 2) Pipelines (Alts 3 and 4) Pumps (Alts 1, 2, 3, and 4) Source: LWRP 2020 Plan to be acquired to accommodate all the new structures. Alternatives 1 and 3 would maintain the existing oxidation ponds (16 mgd) and construct an additional 10 mgd of conventional activated sludge (CAS) secondary treatment. The other two alternatives (2 and 4) would convert the existing oxidation ponds to storage reservoirs and construct a 26 mgd-capacity CAS secondary treatment system within the footprint of the existing plant Figure 3-4 shows the proposed location of new treatment facilities on the existing LWRP for Alternatives 1 and 3. Figure 3-5 shows the proposed location of new facilities for Alternatives 2 and 4. Final LWRP 2020 Plan EIR 3-4 May 2004

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7 Proposed Agricultural Area AVE A Nebeker Ranch Proposed Storage Reservoirs Existing Force Main Proposed Effluent Force Main Edwards Air Force Base Boundary AVE B Alternate Storage Reservoirs Nebeker Ranch ROSAMOND DRY LAKE AVE C Buffer Pond C-Dike PIUTE PONDS Discharge Ditch Western Agricultural Area LWRP Impoundment Areas AVE D EDWARDS AIR FORCE BASE Antelope Acres AVE E 14 SIERRA HWY Amargosa Creek 80 TH ST W 70 TH ST W 60 TH ST W 50 TH ST W 40 TH ST W 30 TH ST W DIVISION ST AVE F Apollo Park 0 1 Miles SOURCE: County Sanitation Districts of Los Angeles County AirPhoto, USA, 2000 LWRP 2020 Plan EIR / Figure 3-2 Project Site Locations Lancaster Water Reclamation Plant and Western Agricultural Area

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9 SOURCE: Los Angeles County Sanitation Districts LWRP 2020 Plan EIR / Figure 3-4 Alternative 1 and 3 Site Plan Showing Proposed Location of Treatment Facilities

10 XX Sludge Drying Beds Pump Station Sludge Drying Beds Stockpile Area Existing Property Line SOURCE: Environmental Science Associates Equalization Basin Flare Station Sludge Drying Beds Pump Station Sludge Drying Beds Pump Station Sludge Digester Tanks Primary Odor Control Station Sedimentation Tanks Conventional Activated Sludge Ferrous Chloride Station Area Reserved for Future Expansion Dissolved Air Flotation Units Compressor Building Chemical Station Influent Pump Station Comminutor Influent Odor Control Station Laboratory Te r tiary Treatment Disinfection Existing Facilities Proposed Facilities North LWRP 2020 Plan EIR / Figure 3-5 Alternative 2 and 4 Site Plan Showing Proposed Location of Treatment Facilities

11 The CAS facilities to be constructed will include aeration tanks, compressors, return activated sludge wetwells and pumps, final sedimentation pumps, dissolved air flotation (DAF) units and chemical stations. The CAS facilities would be constructed mostly within the existing LWRP property, but would require acquisition of approximately five to 15 acres adjacent to the LWRP. Under Alternative 2, the existing oxidation ponds would be converted into storage reservoirs, lessening the off-site acreage acquisition requirements for storage reservoirs by approximately 270 acres (See Table 3-1). Under all alternatives, the AVTTP would be decommissioned. Tertiary treatment facilities will be constructed following CAS secondary treatment to provide from 10 mgd to 26 mgd tertiary-treated effluent, depending on the alternative, for Apollo Park and emerging reuse applications, such as the City of Lancaster's municipal reuse project. Under Alternatives 1 and 3, up to 10 mgd of tertiary treatment capacity would be constructed, while up to 26 mgd of tertiary treatment would be constructed under Alternatives 2 and 4. The major facilities that will be constructed as part of the tertiary treatment include filters and, backwash recovery tanks. In addition the tertiary effluent will be disinfected via, chlorine contact tanks and dechlorination facilities. The tertiary treatment process would include filtration and disinfection. Disinfection would be accomplished using sodium hypochlorite. Under each Aalternatives 1 and 3, a 5 mgd dechlorination facility will ould also be constructed. following oxidation pond secondary treatment. In addition, up to 16 mgd of nitrogen removal facilities may also be constructed under each Aalternatives 1 and 3. The expanded tertiary facilities will be located on the existing LWRP site. Biosolids Processing Under each alternative, District No. 14 would construct additional solids processing facilities including pumps, anaerobic digesters, and drying beds. All residual solids generated during the wastewater treatment process will continue to be processed at the LWRP. Currently, biosolids generated at the plant are removed from the digesters and placed on concrete-lined drying beds located north of the treatment facilities. After sufficient drying time, the biosolids are stored temporarily and then placed in trucks and transported off site for disposal or beneficial reuse. The LWRP 2020 Plan will modify and expand the existing biosolids management system at the LWRP site. Biosolids will continue to be dried in drying beds and hauled off site for disposal and/or reuse. Table 3-4 summarizes 2002 and projected biosolids production and haul trips necessary for disposal. Final LWRP 2020 Plan EIR 3-10 May 2004

12 Table 3-4 Current and Projected Biosolids Production at Lancaster Water Reclamation Plant DRY TONS PER YEAR (tpy) TRUCK TRIPS PER YEAR Alternatives 1 and 3 (2020) 2, Alternatives 2 and 4 (2020) 3, Source: LWRP 2020 Plan Effluent Management The LWRP 2020 Plan will maintain existing effluent management facilities and increase reuse operations. Discharge to Piute Ponds will decrease from the current annual daily average of 6.2 mgd, which resulted in unauthorized effluent-induced overflows to Rosamond Dry Lake, to an annual average of approximately 2.6 mgd, which is sufficient to maintain Piute Ponds at its current size of 400 acres. Effluent delivery to the Impoundment Areas and Apollo Park will not change throughout the planning period. The increased effluent management capacity needed will be met primarily with increased agricultural reuse operations and storage reservoirs under Alternatives 1 and 2, and primarily with increased agricultural reuse operations and effluent land application under Alternatives 3 and 4. Figure 3-6 provides a flow chart of the existing and proposed effluent management systems. Agricultural Reuse Each alternative provides for agricultural reuse as the principal means of effluent management during the summer months. Two large agricultural areas have been identified near the LWRP from which District No. 14 would acquire the necessary acreage to implement the proposed large-scale agricultural reuse operations. The two areas are referred to in this report as the wwestern aagricultural aarea and the eeastern aagricultural aarea. Under Alternatives 1 (Recommended Project) and 2 (Recommended Project), the agricultural reuse operations would be sited within the eastern agricultural area, while under Alternatives 3 and 4 District No. 14 would acquire land within both of these areas. District No. 14 would acquire up to 4,170 acres under Alternative 1 and 4,650 acres under Alternative 2 for agricultural reuse operations, while under Alternatives 3 and 4, District No. 14 would acquire up to 13,880 acres and 13,940 acres, respectively for agriculturale reuse and effluent land application operations. The actual location of agricultural reuse operations may differ from the identified eastern and western areas, depending on the emergence of farming entities willing to use recycled water. A pump station and Final LWRP 2020 Plan EIR 3-11 May 2004

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14 pipeline will convey effluent to the Eeastern Aagricultural Aareas, while an additional pipeline would be required to convey effluent to the Wwestern Aagricultural Aarea under Alternatives 3 and 4. The preferred agricultural areas and pipeline routes are shown in Figures 3-2 and 3-3. Other pipeline routes following existing roadways could also be utilized within the assessment area evaluated in this LWRP 2020 PlanFinal EIR to ensure efficient conveyance of irrigation water. A steel storage tank will be constructed in the Eastern Agricultural Area to provide equalization for the recycled water pipeline and distribution system. The need for this tank was not recognized during preliminary designs, and was not included in the project description or impact analysis of the Draft EIR. As a result, District No. 14 will evaluate the need for this project component and the potential impacts to environmental resources in a separate process pursuant to CEQA requirements. The tank will not be constructed until separate CEQA evaluations are certified by the District No. 14 Board of Directors. District No. 14 may minimize the need to develop portions of the agricultural operations required within the agricultural areas by entering into contracts with existing farming entities and providing recycled water from the LWRP for irrigation purposes. In addition, if opportunities arise in the future to sell or provide water to farming entities outside of the identified agricultural areas, District No. 14 will consider the opportunities as a means of meeting the overall LWRP 2020 Plan reuse goals. District No. 14 currently conveys undisinfected, secondary-treated wastewater to Nebeker Ranch located northwest of the LWRP, where a private operator uses the water to cultivate alfalfa. District No. 14 is currently negotiating to purchase the acre ranch, or extend the existing recycled water contract with the operator. Acquisition, or extension of the contract with, Nebeker Ranch, would secure acres of the needed agricultural lands. If use of Nebeker Ranch is discontinued, then the entire acreage indicated in Table 3-1 would have to be acquired..additional land would be acquired within the identified agricultural areas to compensate for the loss. Agricultural operations would either be managed by District No. 14 or leased to qualified farming entities. The reuse operations would comply with DHS requirements for the use of recycled water included in CCR Title 22. District No. 14 will obtain WRRs from the RWQCB-LR authorizing irrigation methods and effluent quality. Initially, it is anticipated that the agricultural operations will cultivate alfalfa utilizing center-pivot sprinkler irrigation methods. Figure 3-7 shows typical sprinkler irrigation equipment to be used. The farming areas may include retention basins (to hold water before it is applied as irrigation) and tail water catch and pump basins (to collect runoff). During the summer months, District No. 14 will apply irrigation water at rates that Final LWRP 2020 Plan EIR 3-13 May 2004

15 SOURCE: Environmental Science Associates LWRP 2020 Plan EIR / Figure 3-7 Proposed Sprinkler Irrigation Pivot System

16 comply with the agronomic rates 1 for crops grown for each alternative. During the winter, Alternatives 1 and 2 would provide storage to prevent over-application beyond the crop agronomic rates. Alternatives 3 and 4 would include effluent land application during the winter months, which involves application of recycled water over a larger acreage than Alternatives 1 and 2, but above crop agronomic rates. Figure 3-8 depicts the average monthly evapotranspiration rate (ET) for alfalfa (ETalf). As indicated in the figure, the water demand for alfalfa is high in the summer but drops below average precipitation rates in the winter. As shown in the figure, the ETalf corresponds with local evaporation rates. Average rainfall is generally sufficient to meet alfalfa ETalf rates during the winter months. During rainy days, irrigation water is typically not applied. During exceptionally dry years, some irrigation during December and January may be necessary. During exceptionally wet years, irrigation may not be necessary in the early spring. However, the amount of land required to maintain evapotranspiration rates for a winter crop (ETc) is prohibitively large without storage reservoirs. Furthermore, during rainy days, recycled irrigation water is typically not applied. Under Alternatives 1 and 2, if operations are conducted during the winter months, the ETalfc during the winter will dictate the volume of water applied to the fields. The remaining effluent during the winter months (November through April) will be conveyed to storage reservoirs for use during the summer months when ETalfc rates are higher. Land Application Alternatives 3 and 4 would involve effluent land application during the winter months, which eliminates the need for any additional storage reservoirs. Land application would not be restricted to crop ETc rates. To accommodate 2020 flows in the winter months (November through April), agricultural operations under Alternatives 3 and 4 would require up to 13,880 acres and up to 13,940 acres, respectively, for land application. During the summer months (May through October), the farming operations would adhere to crop ETc rates. Since it is unlikely that storage reservoirs will be constructed prior to the August 25, 2005 overflow deadline, District No. 14 would have to operate the agricultural operations under Alternatives 1 and 2 as land application operations during the winter months for an interim period until the storage reservoirs are 1 Agronomic rates refer to optimal water and nutrient needs for specific crop types. ETc and nitrogen fertilizer requirements are examples of agronomic rates. These rates can vary seasonally and by location. Final LWRP 2020 Plan EIR 3-15 May 2004

17 Figure 3.8: Evapotranspiration Rate and Precipitation in the Project Vicinity 15 alfalfa ETalf Inches per Month 10 5 Lancaster average precipitation Lancaster Evapotranspiration (ETo) 0 jan feb mar apr may jun july aug sep oct nov dec Source: LWRP 2020 Plan Western Regional Climate Center. Monthly Climate Summary for Lancaster FSS constructed. This would ensure that unauthorized effluent induced overflows are eliminated by August 25, Storage Reservoirs Each alternative includes some peak flow storage capacity. Alternatives 1 and 2 include the construction of the maximum amount of storage reservoirs needed to prevent overflows onto Rosamond Dry Lake while minimizing the need for land application. Alternatives 3 and 4 would not involve construction of any new storage reservoirs. The existing storage reservoirs would be used as back-up to avoid runoff during storm events. The new storage reservoirs under Alternatives 1 and 2 would be constructed as rectangular or trapezoidal modules ranging in water surface area from 36 to 5860 acres. The reservoirs would have a maximum Final LWRP 2020 Plan EIR 3-16 May 2004

18 water depth of approximately 1120 feet and a freeboard of 3 feet. Under Alternative 1, a high density polyethylene geomembrane (i.e., synthetic liner) would be constructed on the floors of the storage reservoirs; while under Alternative 2, A liner with the floors of the storage reservoirs low hydraulic conductivity will be constructed from excavated and recompacted native soil, which has low permeability. Construction of storage facilities would require acquisition of 1,100 acres under Alternative 1 and 750 acres under Alternative 2. A total of 16 storage reservoirs would be constructed under Alternatives 1 and 2. The preferred location for the storage reservoirs would be north of the LWRP, as shown in Figure 3-1. Alternative locations for storage reservoirs considered in this Final EIR would be south of the LWRP, southeast of the LWRP, east of the LWRP on EAFB, or west of SR-14. as shown in Figure 3-2. Chapter 5.0 of this document describes the evaluation of alternate storage reservoir locations. Although all reasonable efforts are being made to have facilities in place to meet the RWQCB-LR deadline, all Stage V effluent management facilities will not be completed in time. The process of acquiring land for agricultural operations and storage reservoirs is anticipated to last through the summer of 2005 due to the significant number of parcels that will be involved and the necessary legal requirements that must be complied with for public acquisition of land. The pump station and pipeline to the proposed agricultural reuse sites east of the LWRP is scheduled for completion in the summer of 2006, while the Stage V storage reservoirs are scheduled for completion in early District No. 14 will manage effluent from the LWRP by delivering recycled water to the existing effluent management sites (Piute Ponds, Impoundment Areas, Apollo Park, Nebeker Ranch, and existing storage reservoirs), and applying recycled water at defined irrigation rates on the Stage V agricultural reuse sites as they are established. During the winter months, when evaporation rates and reuse demand are low, District No. 14 will continue its present practice of controlled effluent discharge to Piute Ponds in a manner that does not create a threatened nuisance condition for EAFB. Although the Stage V storage reservoirs are expected to be complete in early 2007, the CAS and tertiary treatment facilities are not scheduled for completion until the summer of Using the Stage V reservoirs for storing oxidation pond effluent from early 2007 to the summer of 2008 may not be acceptable to the RWQCB-LR. After the summer of 2008, tertiary effluent will be available for agricultural and municipal reuse operations and surplus effluent will be stored in the Stage V reservoirs during the winter months. As these facilities become operational, effluent-induced overflows onto Rosamond Dry Lake will be greatly reduced. All effluent overflows onto Rosamond Dry Lake will be eliminated after April District No. 14 is working with the RWQCB-LR and EAFB to ensure that continuation of controlled effluent overflows during this period does not create a threatened nuisance condition. Final LWRP 2020 Plan EIR 3-17 May 2004

19 Municipal Reuse Under each alternative, a portion of the LWRP's effluent management needs will be satisfied by municipal recycled water reuse operations, such as that of the City of Lancaster's municipal reuse project. The city has requested up to 1.5 mgd of tertiary-treated recycled water for municipal landscape irrigation projects. The reuse project will satisfy a small portion of the additional effluent management needs for the LWRP during the summer months when demand for water is high, as well as reduce the city s demand for imported water and groundwater. The LWRP 2020 Plan includes construction of tertiary treatment facilities required to provide recycled water suitable for the city's proposed project, but will not include construction of the distribution system or development of the municipal irrigation projects. When the city is ready to receive recycled water, no additional CEQA review will be required by the District No. 14. The city will prepare the necessary environmental analysis to comply with CEQA for implementation of its municipal reuse project. Management of Piute Ponds Each alternative would maintain the existing footprint of Piute Ponds. Secondary treated effluent is currently discharged to an approximately 15.0-mgd capacity ditch on the east end of the existing storage reservoirs (see Figure 3-2). The ditch empties into Amargosa Creek which feeds Piute Ponds. The LWRP discharge is the only consistent supply of water to the ponds. Piute Ponds will be supplied with a yearly average of approximately 955 MG (2.6 mgd) of effluent. This is a reduction from the average of 6.9 mgd discharged to Piute Ponds and the adjacent Impoundment Areas in The exact daily volume to Piute Ponds and the Impoundment Areas will vary with the seasonal evaporation rates and any flushing requirements. The LWRP 2020 Plan provides sufficient quantities of recycled effluent from the LWRP to maintain the wildlife and recreational uses of Piute Ponds and Impoundment Areas without causing unauthorized effluent-induced overflows to Rosamond Dry Lake. No other changes to the configuration or management of Piute Ponds are proposed under the LWRP 2020 Plan. Of the effluent discharged to Piute Ponds and the Impoundment Areas, approximately 95 MG annually will be delivered to the Impoundment Areas. Most of this effluent, 55 MG, will be supplied in November to fill the impoundments after they dry out over the summer months. This amount is similar to the existing conditions. No effluent is allowed into the Impoundment Areas from April 15 through October 31 unless approved by EAFB. Final LWRP 2020 Plan EIR 3-18 May 2004

20 District No. 14 staff will continue to collect water samples as part of the monitoring program required by the WDRs. Water sample analytical results will be submitted to the RWQCB-LR per the WDR requirements. Apollo Park Approximately 56 MG per year of tertiary treated effluent will continue to be conveyed to Apollo Park. The recycled water is used to maintain a series of recreational lakes that are open to the public. Peak Flow Management The LWRP experiences peak flows during winter storm events due to infiltration and inflow into the collection system. These peak flow periods also correspond to periods of reduced discharge capacity due to reduced irrigation needs. A peaking factor of 2.6 was used to generate the peak storm flow design capacity, based on historic inflow metered at the LWRP facility. However, the effluent management system would be sized for an average sanitary flow of 26 mgd, since the existing influent equalization basin, along with the existing oxidation ponds, and the storage reservoirs would equalize peak storm flows, which typically are of short duration. To accommodate peak storm flows, Alternatives 1 and 2 will provide for additional storage reservoirs designed to accommodate a peak storm flow rate of 67.6 mgd. The 24-hour rainfall intensity during thea two-year storm event is approximately one inch in the Antelope Valley. 2 During infrequent storm events (approximately once every two to four years), rain can fall with enough intensity in the Amargosa Creek watershed to induce overflows from Piute Ponds to Rosamond Dry Lake. Storm-induced overflows onto the dry lake are permitted by the RWQCB-LR. During these periods, the LWRP will discharge to Amargosa Creek an amount equal to the evaporation rate from Piute Ponds. Property Acquisition District No. 14 will have to acquire a substantial amount of land for wastewater treatment, biosolids handling facilities, and effluent management facilities, (storage reservoirs, and agricultural operations) under each alternative. Figure 3-1 shows the approximate location of property under consideration for acquisition. Table 3-5 summarizes the acreage requirements for each alternative for both Stage V and VI. 2 National Oceanic and Atmosphere Administration, Atlas 2, 1973 Final LWRP 2020 Plan EIR 3-19 May 2004

21 Alternative 1 Chapter 3 Project Description Table 3-5 Land Acquisition Requirements for Each Alternative for Stages V and VI STAGE V (21 mgd) STAGE VI (26 mgd) TOTAL (Stages V & VI) Ag Reuse 3,040 acres* 1,130 acres 4,170 acres* Storage Reservoirs 825 acres 275 acres 1,100 acres Alternative 2 Ag Reuse 3,180 acres* 1,470 acres 4,650 acres* Storage Reservoirs 6470 acres** 280 acres 750 acres*** Alternative 3 Ag Reuse / Land Application Alternative 4 Ag Reuse / Land Application 11,040 acres* 2,840 acres 13,880 acres* 11,040 acres* 2,900 acres 13,940 acres* * Acquiring, or extending contract with, Nebeker Ranch would secure acres of the amount indicated. **Includes adjustment (down) due to utilization of 60 of the approximately 270 acres of available oxidation ponds for storage. ***Includes adjustment (down) due to utilization of allapproximately 270 acres of available oxidation ponds for storage. Note: all acreages indicated above are the total required (i.e., include buffer, roads, berms, etc.) It is the intent of District No. 14 to purchase these properties from the current owners. However, the use of eminent domain may be required in some cases. In these cases, District No. 14 will compensate all the land owners at a the fair market value price and will provide legally mandated relocation assistance to for displaced individuals, if necessary. District No. 14 will likely acquire all the land necessary for the projected 26.0 mgd flow rate for the year 2020 prior to the implementation of construction,.in order to secure all necessary land for the phased construction of the project. At this time, the exact parcels to be acquired have not been identified. Figure 3-2 and Figure 3-3 show the areas in which property will most likely be acquired. Other alternative land areas are described in Chapter 5.0 of this report. The two main areas being assessed by District No. 14 for agricultural operations are the wwestern aagricultural aarea, which encompasses the general area west of 45 th Street West to 70 th Street West and south of Avenue A-8 to Avenue E, and the eeastern aagricultural aarea, which is bounded by Avenue D to the north, Avenue G to the south, 100 th Street East to the east and 50 th Street East to the west. District No. 14 may have to pursue acquisition of property beyond the footprints described herein to meet the project objectives. The proposed locations for the storage reservoirs for Alternatives 1 and 2 as shown on Figure 3-1 would not require displacement of current residents, since no homes exist within the proposed facility footprint. However, acquisition of the agricultural property could involve the displacement of up to 25 single-family Final LWRP 2020 Plan EIR 3-20 May 2004

22 homes residences in the wwestern aagricultural aarea and/or up to 56 homes residences in the eeastern aagricultural aarea. Once the project has been approved by the Board of Directors for District No. 14, the acquisition areas will be finalized. Once the project has been approved by the Board of Directors for District No. 14, the parcels to be acquired will be determined and negotiations for purchase will begin. 3.3 CONSTRUCTION METHODS Construction of the facilities required for Stage V of the LWRP upgrade and expansion will occur once the permitting and land acquisition process is completed. The following facilities will be constructed as part of Stages V and VI of the recommended project: 10 mgd of preliminary treatment, Pprimary treatment, and odor control facilities; 26 mgd of CAS treatment facilities; Dechlorination facilities; Up to 526 mgd of tertiary-treatment facilities; 10 mgd of Bbiosolids handling facilities; 4,650 acres of agricultural operations; Storage reservoirs with a storage volume of approximately 2,300 MG; and. A recycled water distribution system (pipeline, storage tank, and pump station). Construction of the preliminary treatment, primary treatment, CAS, and odor control facilities will take place within the existing footprint of the LWRP. The tertiary treatment facilities and biosolids handling facilities will require acquisition of additional acreage adjacent to the LWRP. Table 3-1 lists the facilities to be constructed during both construction stages for each alternative. Table 3-6 lists the construction equipment necessary to construct the new treatment facilities. Final LWRP 2020 Plan EIR 3-21 May 2004

23 Table 3-6 Potential Equipment List for Stage V Construction Activities STORAGE RESERVOIR PIPELINE CONSTRUCTION INSTALLATION Chapter 3 Project Description TREATMENT FACILITIES Off-Road Graders 3 None 1 Dozers 1 None 1 Trenchers/Loaders Jack and Bore Drill Rig None 1 None On-Road Pick Up trucks Delivery Trucks (daily) Number of workers per shift Number of hafts Construction duration 14 months 8 months 17 months Source: District No. 14 Construction of the storage reservoirs will involve grading the affected area and constructing the berms that form the levees around these impoundments. It is anticipated that on site soils will be of adequate quality for berm use minimizing the need to import soil to the site for berm construction. It is anticipated that compacted native soil will be excavated and recompacted to construct the floor of the storage reservoirs liners with a low hydraulic conductivity. Completion of the reservoirs will entail installing supply pipelines and pump stations. Access roads will be constructed around the edge of each reservoir, as will drainage structures. Under Alternatives 2 and 4, the existing oxidation ponds would be emptied and cleaned and converted into storage reservoirs. by building up the existing berms. Table 3-6 lists the anticipated equipment to be used during the construction of the reservoirs. Pipelines for conveying recycled water to the agricultural operations will be installed within County road easements. The force-mainpressurized pipelines will be up to 42 inches in diameter, installed at a depth of at least 30 inches below the ground surface. A minimum of 100 feet of pipeline will be installed per day using open trench construction methods. The conveyance system will require pump stations and terminal hook ups located near the new storage reservoirs. An approximately 2-million-gallon-capacity storage tank will be constructed in the southeast corner of the Eastern Agricultural Area to provide equalization for the recycled water pipeline and distribution system. The need for this tank was not recognized during preliminary designs, and was not included in the project description or impact analysis of the Draft EIR. As a result, District No. 14 will evaluate the need for this project component and the potential impacts to environmental resources in a separate process pursuant to CEQA requirements. The tank will not be constructed until separate CEQA evaluations are certified by District No. 14 Board of Directors. Table 3-6 summarizes the equipment requirements for the pipeline installation. Final LWRP 2020 Plan EIR 3-22 May 2004

24 Jack and bore construction methods will be used to install the recycled water pipeline across the Antelope Valley Freeway (SR-14) and the Sierra Highway. under Alternatives 3 and 4. Jack and bore methods require that work areas be established on either side of the roadway. The drilling rig would excavate a horizontal tunnel under the highway and the pipeline would be installed without impacting the flow of traffic on the highway. No road closures on SR-14 or the Sierra Highway would be necessary. However,; lane closures may be necessary on Sierra Highway. The pipeline would be installed with trenching methods at all other roads and intersections. Therefore, some temporary road closures to local access roads may be necessary during trenching activities. Land Conversion to Agricultural Operations As part of the implementation of Stage V, newly acquired property will be prepared for agricultural use. Conversion to agricultural operations will include clearing the land of any existing structures, including homes and appurtenant facilities. Once the structures have been removed, abandoned wells will be capped, and the areas will be cleared, disced, plowed, and prepared for planting. The equipment required to do this work includes dozers, graders, and tractors. 3.4 ENVIRONMENTALLY SUPERIOR ALTERNATIVE CEQA requires that an EIR identify the environmentally superior alternative. The No Project alternative is environmentally superior with respect to biological resources and construction impacts, but unacceptable with respect to the project objectives. The four project alternatives evaluated in the LWRP 2020 PlanFinal EIR have environmental tradeoffs. Alternatives 3 and 4 could eventually result in degraded groundwater quality as a result of effluent land application activities. Therefore, Alternatives 1 and 2 are the environmentally superior action alternatives. Since Alternative 2 would provide additional treatment, the potential for groundwater degradation will be less than Alternative 1. Therefore, Alternative 2 is the environmentally superior alternative. Each alternative has lower impacts in some areas, but higher impacts in other areas. Table 3-7 summarizes the tradeoffs. Alternatives 3 and 4 would require acquisition of more than twice the land required under Alternatives 1 and 2. Land application activities under Alternatives 3 and 4 would result in infiltration rates that could impact groundwater quality. Conversely, the construction of the storage reservoirs for under Alternatives 1 and 2 would impact the flood plain and local aesthetics as well as identified mariposa lily populations not affected in the agricultural areas. Final LWRP 2020 Plan EIR 3-23 May 2004

25 Table 3-7 Comparison of Alternatives Potential Impact Alternative 1 Alternative 2 Alternative 3 Alternative 4 Land Acquisition (acres) Agricultural Operations 4,170 4,650 13,880 13,940 Storage Reservoirs Wastewater Treatment 1, Total Acreage 5,275 5,415 13,885 13,955 Displacement Residences potentially Less Less More More displaced Effluent Quality Disinfection Yes Yes Yes Yes Nitrate levels More Less More Less TDS levels (mg/l) ~ 588 ~ 588 ~ 588 ~ 588 Biosolids Biosolids disposal (tons/yr) 2,250 3,260 2,250 3,260 Air Emissions Sludge ddigester gas Less More Less More Biosolids disposal truck Less More Less More trips Chemical Storage NaOCl and ammonia More Less More Less Biology Elimination of mudflat habitat Maintenance of Piute Ponds Alkali mariposa lily habitat loss Elimination of dry land habitat potentially used by sensitive species such as Mohave ground squirrel Same Same Same Same Same Same Same Same 1, acres acres None None Same* Same* Same* Same* Hydrology Flood plain encroachment More More Less Less Piute Ponds water quality Same Same Same Same Groundwater quality impact Less Less More More Construction (noise, traffic, air) More More Less Less * Although Alternatives 23 and 4 would grade more total acreage, much of the agricultural land in the eastern agricultural area is pre-disturbed or otherwise of low habitat value for sensitive species. As a result, the reduction of quality habitat for each alternative is considered generally equivalent SCHEDULE Stage V will be constructed as various sub-projects. Construction on certain sub-projects is scheduled to begin as early as September All of the Stage V facilities are scheduled for completion by MayJune Construction of the Stage VI facilities is scheduled to begin in November 2012 and is scheduled for completion by late The property acquisition phase for Stage V is anticipated to require approximately 1624 months, and will overlap final design, and bid and award of the first Stage V Final LWRP 2020 Plan EIR 3-24 May 2004

26 sub-project. The property needed for both stages will be acquired during to the commencement of the Stage V expansion. 3.6 APPROVALS REQUIRED Implementation of the LWRP 2020 Plan will require approval from numerous agencies including the following: RWQCB-LR, WDRs; RWQCB-LR, WRRs; DHS, recycled water reuse system approvals; DFG, California Endangered Species Act (Cal-ESA) consultation; California State Office of Historical Preservation, SRF required consultation; Antelope Valley Air Quality Management District (AVAQMD), air emissions permits; Los Angeles County Department of Public Works, construction easement; California Department of Transportation (Caltrans), construction easement; and. Los Angeles County Department of Regional Planning, Conditional Use Permit (CUP). Final LWRP 2020 Plan EIR 3-25 May 2004