SOUTH FEATHER WATER AND POWER AGENCY OROVILLE, CALIFORNIA MINERS RANCH WATER TREATMENT PLANT EXPANSION PROJECT SUMMARY REPORT

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1 SOUTH FEATHER WATER AND POWER AGENCY OROVILLE, CALIFORNIA MINERS RANCH WATER TREATMENT PLANT EXPANSION PROJECT SUMMARY REPORT DRAFT June 2009 A SACRAMENTO, CA WALNUT CREEK, CA

2 Miners Ranch Water Treatment Plant Improvements Project Contents Executive Summary...1 Section 1 - Introduction 1.1 Purpose Project Objectives... 4 Section 2 Summary Scope of Modifications 2.1 Phase 1 Expansion to 21 MGD Direct Filtration and Conventional Treatment Trains Raw Water Pump Station Filters Clearwell, High Service Pump Station, and UV Disinfection Chemicals Residuals Handling Electrical Modifications General Raw Water Pump Station Flocculation, Filter, and Washwater Improvements High Service Pumps and UV Chemical Feed Facilities Instrumentation and Control Phase 2 Ultimate Build-out Other Factors Distribution System Improvements Greenhouse Gas Emission Considerations Section 3 Implementation 3.1 Next Stages Schedule Section 4 Cost Estimate...22 Appendix A Greenhouse Gas Analysis Background...23 A i

3 Executive Summary This Summary Report presents the findings and recommendations for process improvements and expansion of the South Feather Water & Power Agency s (Agency s) Miners Ranch Water Treatment Plant (MRWTP). To address regulatory, capacity and flexibility concerns, recommended improvements and expansion of MRWTP will be staged into in two phases: Phase 1 - Enhance mixing, clarification, filtration, disinfection and residuals handling facilities and practices. Expand the plant to 21 million gallons per day (mgd) treatment (design) capacity; this corresponds to 18 mgd firm capacity with one filter out of service. The 21 mgd design capacity will satisfy projected water demands for the next 30 years. Phase 2 Expand the plant to 29 mgd design capacity (25.4 mgd firm capacity with one filter out of service) should water demands in the systems approach the plant s design capacity of 21 mgd. Because the Phase 2 improvements are not anticipated for the next 30 years, this Report focuses on Phase 1. Phase 1 improvements will include: Provide 21 mgd of direct filtration pretreatment capacity including: Convert existing sedimentation basin to flocculation basin Construct two new flocculation basins Install variable speed vertical mixers for flocculation Install new 36-inch raw water pipeline Install pumped rapid mix system Expand Raw Water Pump Station by: Replacing existing variable speed 6 mgd pump with a variable speed 8.5 mgd pump. Relocating the pump station electrical to the existing Lime Building. A 1

4 Construct two new settling basins using plate settlers to provide 6 mgd of conventional pretreatment (clarification) capacity. Construct two new filters and extend the filter gallery building. Modify existing filters with new underdrains, air scour, and new media. Resurface concrete in filter boxes where aggregate is exposed. Construct new High Service Pump Station on clearwell outlet. Provide new chemical storage and feed equipment for coagulants, polymers, and chlorination. Provide secondary containment for coagulant system and scrubber for chlorine system. Construct new 21 mgd capacity UV disinfection system in conjunction with the new High Service Pump Station. Construct a second washwater basin and recycle decanted washwater to head of plant. Construct two additional sludge handling basins to increase sludge thickening capacity. Installing a single-speed 11.5 mgd raw water pump, bringing the firm capacity of the pump station to 18 mgd, is deferred at this point because the firm capacity increase (14.5 to 21 mgd) is not required for a projected 20 years, given current growth rates. This replacement is referred to as Phase 1A in the body of the report. Phase 2 will achieve ultimate build-out to 29 mgd plant capacity, and will include: Add fourth raw water pump sized at 8.5 mgd. Construct two additional filters. Expand UV disinfection system. Table ES-1 summarizes an updated cost estimate for the Phase 1 expansion to 21 mgd. The opinion of cost is conceptual and is provided as a cost for the Agency s use in planning. These costs are presented with an escalation factor to an assumed construction midpoint of 2012, and includes 30 percent prorate to account for unidentified items. A 2

5 Engineering services are assumed to be 25 percent of construction cost and include design, construction management, and engineering services during construction. Pilot- or plant-scale testing; CEQA, and California Department of Public Health (CDPH) permitting; special inspection; materials testing; water quality testing; and the Agency s administrative, legal and funding costs are not included in the estimates. Table ES-1 Conceptual Cost Estimate for Phase 1 Expansion to 21 mgd (18 mgd firm) Convert to Direct Filtration (21 mgd) and Expand Conventional Treatment (6 mgd) Raw Water Pipeline Flocculation Basins/Mixers Pumped Rapid Mix Two Settling Basins $5,200,000 Raw Water Pump Station Expand to 14.5 mgd firm (Phase 1) Expand to 21 mgd firm (Phase 1A) $480,000 $170,000 Filters $4,300,000 High Service Pump Station and UV Disinfection System $3,600,000 Chemical Systems $1,950,000 Residuals Handling $760,000 Construction Cost $16,400,000 Escalation to Construction Midpoint (24%) $3,900,000 Escalated Construction Cost $20,300,000 Engineering Cost (25%) $5,100,000 Total Phase 1 Project Cost $20,400,000 A 3

6 Section 1 Introduction 1.1 Purpose This Summary Report presents the findings and recommendations for process improvements and expansion of the Agency s MRWTP. To address regulatory, capacity and flexibility concerns, recommended improvements and expansion of MRWTP will be staged into in two phases: Phase 1 - Enhance mixing, clarification, filtration, disinfection and residuals handling facilities and practices. Expand the plant to 21 mgd treatment (design) capacity; this corresponds to 18 mgd firm capacity with one filter out of service. The 21 mgd design capacity will satisfy projected water demands for the next thirty years. Phase 2 Expand the plant to 29 mgd design capacity (25.4 mgd firm capacity with one filter out of service) should water demands in the systems approach the plant s design capacity of 21 mgd. Technical Memorandum 1 (TM1; CDM, November 2008) defined the regulatory and operations requirements for the treatment plant expansion, and evaluated the current condition of the various process units at the MRWTP. A workshop was conducted in October 2008, following the Agency s review of Draft TM1, to discuss the findings and identify treatment and expansion alternatives. Technical Memorandum 2 (TM2; CDM April 2009) presented an analysis of improvements and expansion alternatives by process unit. A second workshop was held in March 2009, after the Agency s review of TM2, to select the recommended process and expansion improvements for the MRWTP. 1.2 Project Objectives An important objective for the MRWTP Improvement Project is to reliably meet current water demands and the projected increased water demands anticipated with population growth over the next thirty years. Redundancy, safety and operational flexibility are also important considerations for the project. The expanded plant must meet current and anticipated future drinking water regulations under changing water quality and flow conditions- challenges that limit the existing plant s capacity. The system s current maximum day demand (MDD) is 11 million gallons per day (MGD). In the direct filtration mode, the plant s current design capacity is 14.5 mgd; 10.8 mgd firm capacity (with one filter out of service). Based on an annual growth rate A 4

7 of 1.5 percent for water demand and a time frame of 30 years, TM2 recommended a design capacity of 21 mgd (18 mgd firm). Ultimate build-out capacity in this scenario is 29 mgd (25.4 mgd firm) to account for potential increases in demand such as opportunities to expand the Agency s service area or wholesale treated water to nearby water suppliers. Operation ease and flexibility concerns for the current plant include limited chlorine contact time/disinfection capabilities, limited conventional treatment capacity (3 mgd) and limited treated water storage (1.4 million gallons of effective storage). TM2 recommended expanding the conventional treatment capacity to 6 mgd, and installing ultraviolet (UV) disinfection to address disinfection concerns and allow the plant to use the entire clearwell volume for treated water storage. The existing MRWTP meets all existing federal and state regulations as discussed in detail in TM1. The expanded MRWTP is expected to meet the recently promulgated Long Term 2 Enhanced Surface Water Treatment Rule and the Stage 2 Disinfectants and Disinfection Byproducts Rule. A 5

8 Section 2 Summary Scope of Modifications To address regulatory, capacity and flexibility concerns, recommended improvements and expansion of MRWTP will be staged into in two phases: Phase 1 - Enhance mixing, clarification, filtration, disinfection and residuals handling facilities and practices. Expand the plant to 21 mgd treatment (design) capacity; this corresponds to 18 mgd firm capacity with one filter out of service. The 21 mgd design capacity will satisfy projected water demands for the next thirty years. Phase 2 Expand the plant to 29 mgd design capacity (25.4 mgd firm capacity with one filter out of service) should water demands in the systems approach the plant s design capacity of 21 mgd. Because the Phase 2 improvements are not anticipated for the next thirty years, this Report will focus primarily on Phase Phase 1 Expansion to 21 MGD The scope of the Phase 1 improvements will comprise: Provide 21 mgd of direct filtration pretreatment capacity including: Convert existing sedimentation basin to flocculation basin Construct two new flocculation basins Install variable speed vertical mixers for flocculation Install new 36-inch raw water pipeline Install pumped rapid mix system Expand Raw Water Pump Station by: Immediately replacing existing variable speed 6 mgd pump with a variable speed 8.5 mgd pump. Relocating the pump station electrical to the existing Lime Building. Construct two new settling basins using plate settlers to provide 6 mgd of conventional pretreatment (clarification) capacity. A 6

9 Construct two new filters and extend filter gallery building. Modify existing filters with new underdrains, air scour, and new media. Resurface concrete in filter boxes where aggregate is exposed. Construct new High Service Pump Station on clearwell outlet. Provide new chemical storage and feed equipment for coagulants, polymers, and chlorination. Provide secondary containment for coagulant system and scrubber for chlorine system. Construct new 21 mgd capacity UV disinfection system in conjunction with the new High Service Pump Station. Construct a second washwater basin and recycle decanted washwater to head of plant. Construct two additional sludge handling basins to increase sludge thickening capacity. Installing a single-speed 11.5 mgd raw water pump, bringing the firm capacity of the pump station to 18 mgd, is deferred at this point because the firm capacity increase (14.5 to 20 mgd) is not required for twenty years at current growth rates. This replacement is referred to as Phase 1A in the discussion. A plant process flow diagram for the recommended scope is shown in Figure 2-1. A corresponding site plan is shown in Figure Direct Filtration and Conventional Treatment Trains Conversion to direct filtration will provide mixing of coagulant chemicals and a flocculation train to produce floc suitable for either filtration or settling. Mixing of coagulants will be provided in a pumped rapid mix system located just upstream from the flocculation basins. The pumped rapid mix system will consist of dedicated mixing pumps that draw water from the main raw water pipeline and inject the pump discharge at the point of chemical addition. The pump discharge piping and infection nozzle will be designed to provide enough mixing energy to ensure efficient coagulation. The pumps (one duty and one standby) will be sized at approximately 700 gpm each. The existing sedimentation basin will be converted to a three stage flocculation basin with vertical variable speed mixers. Additionally, two more flocculation basins will be constructed to provide sufficient detention time at the anticipated range of flows. A 7

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12 Conceptual plan views of the flocculation and settling basins are shown in Figure 2-3. Figure 2-3 shows flocculated and settled water channels for conveyance of water directly to filters or to the settling basins. The slide gate arrangement will allow the operator to direct the water through the flocculated water channel to the settled water channel (direct filtration mode) or to the settling basins (conventional treatment mode). The existing overflow weir in the settled water channel will be kept, but raised from the current elevation to elevation 920 (the existing outflow weir has a board raising the elevation to approximately 920; the weir will be raised with a permanent concrete structure). Settling basins will be configured with plate settlers and mechanical sludge removal equipment, such as a cable driven sludge suction header. Settling capacity of each basin will be 3 mgd; thus, overall conventional treatment capacity will be 6 mgd for Phase 1. Mechanical sludge removal will provide continuous sludge removal. Sludge will flow by gravity to an extension of the existing 20-inch overflow piping down to the washwater basins Raw Water Pump Station The existing variable speed 6.5 mgd pump will be replaced with a variable speed 8.5 mgd pump. This new pump combined with existing pumps will provide a firm pumping capacity of 14.5 mgd, which will address plant capacity needs for almost twenty years, based upon 1.5 percent annual growth rate. Future replacement (defined as Phase 1A) of the second 6.5 mgd pump with another 11.5 mgd will increase the firm pumping capacity to 18 mgd. Total dynamic head of the new pump will be approximately 60 feet to provide lift from the reservoir low level of 870 to the maximum water surface elevation of the basin of and overcome friction and minor losses through the piping. The most extensive renovation for the expanded raw water pump station will involve the electrical infrastructure. These improvements are described in Section Filters Two new filters will be constructed, along with renovation of the existing four (4) filters with new underdrains and media. In addition, the filters will be provided with air scour, replacing the current surface-washing mechanisms. Pilot- and/or plantscale testing is recommended to optimize the filter media configuration, and a gravelless underdrain system that supports both air and water washing cycles will be installed. The filter gallery will be extended to house the piping for the new filters with provisions for expansion for the ultimate build-out of eight (8) filters. A 8

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14 Air scour is to be provided by positive displacement blowers (one duty, one standby) to be housed in an annex to the filter gallery. Air will be distributed to the filters by stainless steel piping. Further rehabilitation of the existing facilities will include replacing filter influent valves and pedestals, rehabilitation of the filter boxes where concrete aggregate is exposed, and seismic improvement to the existing filter gallery, if needed. The preliminary design of the plant improvement project should include a structural evaluation of the filter gallery in light of current structural codes. Backwash pumps will remain at the existing High Service Pump Station, which will be converted to a dedicated Backwash Pump Station. The Backwash Pump Station will draw water from the filter discharge prior to entry to the clearwell, as the existing 30-inch post clearwell piping will be taken out of service Clearwell, High Service Pump Station, and UV Disinfection The addition of UV disinfection eliminates the need to use the clearwell for calculating disinfection credits (Ct), and frees up the entire storage volume to be used as system demand requires. To meet future pumped demand needs and to provide for ultraviolet disinfection, a new High service Pump Station and UV disinfection building will be constructed on the south side of the clearwell, as shown in the site plan of Figure 2-2. Figure 2-4 shows a conceptual plan of the new facility. Three new vertical turbine pumps each with a flow rate of 2.4 mgd and total dynamic head of 365 feet will provide firm capacity of 4.8 mgd at the High Service Pump Station; this will meet the Phase 1 pumped demand projection of 4.7 mgd. Currently, the tie-in point for the new pump station discharge pipeline is a 14-inch pipeline. However, TM1 recommended this 14-inch pipeline be replaced with a 20- inch pipeline (see Section 2.3.1). The new discharge pipeline will be sized at 20-inches to reduce headlosses in this run of piping Chemicals Because the chemical feed equipment dates to the original plant construction, all of the feed and storage equipment will be replaced. The current scope for the Phase 1 Improvements assumes replacement of the following equipment: Chlorine cylinder scales Chlorine cylinder vacuum regulators Chlorine automatic cylinder switchover A 9

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16 Chlorinators Chlorine injectors for each feed point (flocculation basins, post filtration, post clearwell) Safety equipment including chlorine scrubber, leak detectors, and ventilation system for chlorine rooms. Coagulant bulk storage tanks. Coagulant metering pumps. Polymer feed batch mixers and metering pumps. The coagulant systems will be designed for continued use of aluminum sulfate, but provide expandability and flexibility for use of other coagulants (i.e., ferric sulfate, polyaluminum chloride solutions, etc.). Secondary containment will be provided in accordance with applicable fire codes and industry standards for liquid bulk storage. Criteria for the chemical systems are shown in Table 2-1. Table 2-1 Chemical System Criteria Coagulant (Alum 48.8% Solution) Average Dosage (as aluminum) mg/l 1 Maximum Dosage (as aluminum) mg/l 3 Bulk Storage Tanks 2 Storage Tank Capacity gallons 7,000 Feed pumps 3 Max. Capacity (each) gph 40 Chlorine Pre-chlorination Max Dosage mg/l 2 Post-chlorination Max Dosage mg/l 2 Chlorinators 3 Capacity (each) lbs/day 500 One-ton Cylinders Storage number 2 Polymer Average Dosage mg/l Feeder Pumps number 2 Filter Aid Capacity gph 25 Backwash Aid Capacity gph 10 A 10

17 2.1.6 Residuals Handling The expanded MRWTP will discontinue discharge of decanted washwater into Miners Ranch Reservoir, and instead recycle clarified washwater to the head of the plant. A second washwater basin will provide additional settling time before recycling. The second washwater basin will have the same dimensions as the existing basin, thus doubling the detention volume to 640,000 gallons. At average filter wash rates of one filter per day, the two basins will provide an average of nine days detention before recycling. The sludge from the washwater basins will be drained/washed into one of three sludge thickening basins (adding two to the existing number of basins). These two additional basins will provide at least two months of detention for sludge thickening, with anticipated sludge concentration of approximately 15 percent solids. The addition of these two basins along the edge of the Miners Ranch Reservoir will require some additional fill to build up the bank. Further refinement of the solids handling procedures will be addressed in the preliminary design. A recycled water pump station will collect the clarified washwater from the washwater basins and sludge thickening basins and pump the water back to the head of the plant. The pump station will be sized not to exceed ten percent of the plant flow. Thus, anticipated capacity for the pump station is 300 to 1,000 gpm, with static lift of approximately 30 feet Electrical Modifications General Preliminary recommendations for electrical modifications include both reuse of existing electrical equipment and addition of new electrical equipment. Description of the existing electrical system is included in TM1. In summary, an overhead electrical PG&E service enters the plant and connects to a 480 Volt AC (VAC) secondary pad mounted transformer located adjacent to the Lime Building. The Main Switchboard (MSB) is located on the outside wall of the Lime Building in a NEMA 3R weatherproof enclosure. The MSB includes PG&E revenue metering, plant service disconnect circuit breaker, automatic transfer switch for the 350 kw diesel powered standby generator, and feeder breakers to the various plant loads and panels. Electrical equipment ratings and components in general were taken from the record drawings and were not verified in the field. During the preliminary design phase, existing equipment will be field verified. Existing electrical equipment is located out of doors and will be approximately 30 years old when the Phase 1 expansion project is constructed. Although 30-year old electrical gear, if well maintained and located in a clean environment, often can be A 11

18 used for many more years, the condition of the existing equipment is not known. To determine if reuse of the equipment is feasible, it must be tested by a qualified electrical testing firm to ensure its condition is sufficient to serve the new equipment and operate until replaced in the Phase 2 expansion. It is anticipated that refurbishing of components (at the minimum), up to complete replacement of gear will be required for Phase 1 expansion. It is anticipated that all of the original era electrical equipment should be replaced as part of the Phase 2 expansion if not sooner. Main Switchboard MSB s maximum electrical capacity is 2000 Amps. The main breaker is presently provided with a trip element that can serve up to 1600 Amps. The added loads will require the breaker to be upgraded with a new 2000 Amp trip element to utilize the full capacity. Calculated loads for the Phase 1A expansion improvements discussed in this summary are approaching the 2000 Amp maximum capacity of the switchboard. Final design loads will need to be re-evaluated to verify that the maximum amp capacity is not exceeded. A table showing the assumed loads is included in Table 2-2. A 12

19 Equipment Location Raw Water Pump Station Flocculation/ sedimentation Filter Area Filter BW Pump Station WW Recycle Pump Station High Service Pumps Ultraviolet (UV) disinfection Admin / Op Bldg Table 2-2 Preliminary Electrical Load Table Existing motor Phase 1 motor Phase 1A motor loads loads loads 2 RW 1 RW 50 3 RW 50 HP ea, HP, 125 HP 125 HP ea 125 HP ea 1 2 HP 4 Filters with motor operated valves (MOVs) 9 2 HP, 2 rapid mix 5 HP 6 Filters including MOVs and 2 BW air scour 25 HP ea Phase 2 motor loads 4 RW 125 HP ea Same as Phase 1 Same as Phase 1 Same as Phase 1 8 Filters including MOVs and 2 BW air scour blowers from Phase 1 2 BW Same as Phase 1 Same as Phase 1 Same as Phase 1 60 HP ea None 2 5 HP Same as Phase 1 Same as Phase 1 1 HS 75 HP, 100 HP, 200 HP ea None Includes chemical feed and storage systems 3 HS 200 HP ea 2 25 KW ea No major additions anticipated Same as Phase 1 4 HS 200 HP ea Same as Phase KW ea Same as Phase 1 Same as Phase 1 Notes: 1. Loads in Horsepower (HP) unless noted. Table shows only major process equipment, not including loads for motor operated valves (MOVs), 120 volt equipment, etc. 2. New High Service Pumps and UV units are located in a new building. Building load includes an allowance for HVAC, not included in the table. Feeder breakers for the new MCC-L and MCC-HS (discussed below) will be added to MSB as shown on Figure 2-5. A new section is being provided for these breakers. The need for a new section and its location will be researched further in the preliminary design phase, and in reviewing the results of the electrical testing recommended above. Phase 2 expansion loads will require replacing the existing MSB with a larger capacity switchboard (not considering age) and getting a larger service from the utility. If electrical testing determines the MSB is of inadequate condition for the Phase 1 expansion, it is recommended that it be replaced with one that is expandable to serve up to Phase 2 loads. New electrical equipment should be located indoors in a central location and out of the elements, to prolong the life and reduce maintenance. For this reason, and A 13

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21 additional reasons noted below, most of the new process equipment will be fed from a new indoor motor control center (MCC) located in the existing Lime Building. This building is centrally located and convenient to both the existing MSB and generator, which are located just outside. Providing a new MCC (identified as MCC-L on the attached Figure 2-6) and other electrical gear will allow a shorter plant shutdown than trying to retrofit the new starters, etc., into the existing equipment. The Lime Building is no longer used for chemical feed equipment and appears to have sufficient space for the new electrical gear. This will be verified in the preliminary design phase. Standby power requirements, including which process units are to be connected to standby power, will be defined in the preliminary design phase. These standby requirements will determine the standby generator loading and capacity Raw Water Pump Station Existing electrical equipment is housed in a small electrical building, and includes a 400 Amp switchboard/mcc SWBD I with a constant speed starter for 50 hp RW Pump 1, a separately mounted variable frequency drive (VFD) for 50 hp pump 2, and a separately mounted VFD for 125 hp RW Pump 3. Planned expansion Phase 1 replaces Pump 2 with a 125 hp pump and new VFD. Interim expansion Phase 1A replaces Pump 1 with a 125 hp pump and new constant speed, reduced voltage solidstate starter. Phase 2 adds a 125 hp Pump 4 and VFD. 18-pulse VFDs will be used in the new construction to limit the effect of harmonics produced by the VFDs. Pump VFDs and reduced voltage starter will be fed from a breaker in MCC-L as shown on Figure 2-6. VFDs and starter will be located in the Lime Building. Although TM2 assumed that the RWPS electrical room and switchboard would be reused for the expansion, it is now recommended that the switchboard be replaced with new equipment located in the Lime Building for the following reasons: As built drawings indicate RWPS switchboard SWBD I cannot provide enough power to supply the loads in Phase 1 and Phase 1A expansions. Pump 3 Robicon VFD is outdated, inefficient and should be replaced in Phase 1. The RWPS electrical building is too small to include the new Phase 1 VFDs and the Phase 1A reduced voltage starter. Construction scheduling and plant shutdown constraints make it difficult and expensive to install new equipment in the same location as the existing. Locating the equipment in the Lime Building provides a central location for maintenance, indoor location for climate protection, and use of an existing building saves the expense of a new or expanded building or weatherproof enclosures that would be required if located near the RWPS. A 14

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23 Flocculation, Filter and Washwater Improvements While removal of several existing loads will provide additional space and capacity for new process equipment, the existing high service pump station outdoor MCC SWBD III does not appear to be in good condition from a cursory observation. Rather than using this for any new equipment, the new MCC-L in the Lime Building will be used to serve the new filter, washwater and flocculator equipment as shown on Figure 2-6. Flocculators and washwater recycle pumps will have standard 6-pulse VFDs mounted in the MCC structure High Service Pumps and UV The new High Service Pump Station (HSPS) building will house both the high service pumps and the UV units. An electrical room is included to house a new MCC (shown as MCC-HS on Figure 2-6), the drives for the high service pumps, the power supply units for the UV units, and other necessary electrical and instrumentation panels. MCC-HS will provide power for the high service pumps and the UV units, plus other miscellaneous loads at the High Service Pump Station, such as motorized valve actuators and HVAC equipment. The proposed single line is shown on Figure 2-6. UV power supply units will be provided with standby power from the generator during outages, but will not be functional for the several seconds before the generator comes on line. This is acceptable based on the relatively small amount of untreated water that would be released. No UPS (uninterruptable power supply) will be provided to keep the UV system constantly powered. Continuous chlorination will provide redundant disinfection, although UV will be the preferred primary disinfection technique. High Service Pumps 1 and 2 and future Pump 4 will be provided with 18 pulse VFDs to limit the effect of harmonics produced by the VFDs. High Service Pump 3 will be provided with a constant speed, reduced voltage solid state starter. The VFDs and reduced voltage starter will be provided with separate floor mounted enclosures and located in the High Service Pump Station electrical room Chemical Feed Facilities Details of the electrical and control needs for the revised chemical systems will be researched during the preliminary design phase. Assumptions for this Summary Report are that the existing equipment will be replaced with similar updated equipment with similar power needs, and any new equipment will have relatively minor power needs Instrumentation and Control Description of the existing control system is included in TM1. In summary, the plant control system (PCS) is based on Allen Bradley (AB) programmable logic controllers (PLCs) and Personal Computers (PC), with Input /Output (I/O) modules located in A 15

24 the Administration Building Control Room and a remote I/O rack located in the Filter Building. During the preliminary design phase the Design Engineer and Agency staff will develop detailed recommendations for new field instruments and additions/upgrades to the control system. The following are some initial recommendations and further options to be addressed during the preliminary design: The control hierarchy for new equipment will be similar to existing: all equipment will have local and remote control. Safety shutdowns will be hardwired and active in both local and remote. When in local, no remote control is available. The same basic PCS equipment and communication and configuration philosophy will be maintained and expanded to include the new facilities. Agency staff has performed work on the existing plant control system in the past. If any upgrades to the existing PLC-5s, PCs, software, etc. are desired or necessary, this work could either be self performed by the Agency or as part of the scope of the Improvements Project s Contractor. Similarly, the programming and configuration of the PLC and HMI screens could be included as part of the Contractor s scope in the Improvements Project, or the Agency could do this work themselves. There may be cost savings if the Agency self-performs the programming and configures the PLC and HMI screens. Spare PLC components are recommended, including one remote I/O adapter module and one each of the different I/O cards. Providing the spare components could be included in the scope of the Improvements Project contract or purchased directly by the Agency. Identify any field instruments that should be sole-sourced to maintain compatibility with the existing, and if there are particular instruments that can t be sole-sourced but are the preferred options. Typically, construction contracts are structured so that a single Instrumentation System Supplier (ISS) has the responsibility for the entire instrumentation system (optionally including the PCS configuration). It will be investigated whether this would be the preferred approach. An alternative is to have the plant staff to take on some of this responsibility. The resolution will likely be dependent on the number and type of instruments in the final design. A remote I/O drop with small UPS, similar to that in the existing filter gallery, will be used at the HSPS. A 16

25 Recommendations for new I/O drops or additions to existing ones will be researched in the preliminary design phase. New HSPS will be tied into the existing fire and security system using door switches on exterior and smoke detectors in electrical and UV rooms. 2.2 Phase 2 - Ultimate Build-out Phase 2 of the MRWTP expansion project involves expanding the plant to ultimate build-out. Because this scenario is anticipated to be thirty years in the future, this Report will not present additional details in addition to those presented in TMs 1 and 2. To achieve ultimate build-out to 29 mgd plant design capacity, Phase 2 will include: Add fourth raw water pump sized at 8.5 mgd. Construct two additional filters. Expand UV disinfection system. 2.3 Other Factors Other considerations for a comprehensive MRWTP Improvement Project will include improvements to the pumped distribution system, and consideration of greenhouse gases the expanded plant will emit Distribution System Improvements In conjunction with improvements at the MRWTP, TM1 noted that several improvements should be considered in the pumped distribution system. These improvements include upsizing the plant discharge pipeline and the mains along Kelly Ridge Road. Additional modeling and a transient analysis are recommended to determine additional details of these pipeline improvements., The gravity feed portion of the distribution system appears to have sufficient gateway capacity from the MRWTP into the distribution system and in the gravity distribution system itself Greenhouse Gas Emissions Considerations Appendix A documents CDM s preliminary analysis of greenhouse gas (GHG) emissions resulting from the MRWTP Phase 1 and 2 expansions. The analysis found that GHG emissions would be well below action levels defined by the California Air Resources Board (CARB) for compliance with the new California Environmental Quality Act (CEQA) GHG regulations. A 17

26 The conservative estimate of the additional power demands for the MRWTP improvements is 1,200,000 kwh per year and corresponds to an estimate of 400 metric tons of carbon dioxide (CO 2 ) equivalents emitted per year to the atmosphere. The GHG estimate for the MRWTP project is well below the interim significance threshold of 7,000 metric tons/year of CO 2 set by CARB for compliance with CEQA. Power demands are estimated to be 60 to 90 percent of the total source of GHG emissions for the project. Therefore a full accounting of cumulative GHG emissions for the entire MRWTP improvements project, which would take into account emissions from other sources such as construction equipment, is also expected to be well below the threshold. A 18

27 Section 3 Implementation 3.1 Next Stages The expansion of the Miners Ranch WTP will proceed through these next stages: preliminary and detailed design, bid phase, construction phase, and startup phase. Preliminary design of the plant expansion including the following tasks: Survey and geotechnical evaluation of the plant site. Detailed evaluation of electrical loads and determination of required electrical infrastructure improvements. Detailed evaluation of instrumentation needs and delivery methods, including Instrument System Supplier and Agency staff coordination of responsibilities. Detailed evaluation and sizing of washwater and sludge handling options. Detailed evaluation of filter gallery structure for compliance with current seismic codes, and recommendations for bringing structure in compliance in conjunction with gallery expansion. Final plant hydraulic profile and sizing of hydraulic components (channels, piping, pumping). Detailed process and instrumentation diagrams for plant processes including conventional treatment, filters, backwashing, ultraviolet disinfection, chemical systems, washwater and sludge handling, and high service pumping. Detailed evaluation of construction scope and determination of how much work the Agency will self-perform. The evaluation will examine such issues as: Agency staff responsibility to General Contractor oversight. Agency responsibility for performance to General Contractor s schedule. Warranty issues that may arise when Agency performed work interfaces with General Contractor s work. Preliminary engineering level opinion of probable construction cost. Optional services for the preliminary design could include: A 19

28 Distribution system hydraulic analysis and transient analysis to determine extent of improvement required to meet Phase 1 expansion flow rates. Subsequent engineering services will include, but may not be limited to: Detailed design production of bidding documents. Permitting of Phase 1 Improvements California Department of Public Heath and California Environmental Quality Act evaluations. Bidding period services production of addenda, answering of bidders questions, and evaluating low bidder s qualifications. Construction period services answering requests for information, construction submittal review, evaluation and preparation of change orders. Startup period services operator training on new facilities, development of an updated O&M Manual, assistance preparing amendment to CDPH operating permit, and optimization of the facility. 3.2 Schedule Because critical project objectives are to reliably meet existing and anticipated regulations under changing water quality conditions and increasing system demands, design and construction should commence as soon as feasible for the Agency. Estimates of durations for the engineering and plant construction activities described above, using a traditional design/bid/build delivery method are shown in Figure 3-1, and include: Preliminary engineering 3 months (not including pilot- or plant-scale coagulant or filter media optimization testing) Detailed design 9 months Permitting 6 months (to run concurrent with detailed design) Bid phase and construction contract award 3 months Construction 18 months Startup 3 months One regulatory milestone that the expansion should endeavor to meet is the October 2013 deadline for compliance with the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) for Schedule 3 systems (serving a population of 10,000 to A 20

29 49,999). Thus, counting back from this milestone requires that preliminary engineering start no later than the beginning of 2011 to meet the LT2 deadline Task Dur. Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Preliminary Engineering Detailed Design/Permitting Bid Phase and Contract Award 3 mo 9 mo 3 mo Construction Phase 18 mo Startup Phase 3 mo Figure 3-1. Miners Ranch WTP Expansion Project Phase 1 Schedule A 21

30 Section 4 Cost Estimate Table 4-1 summarizes an updated cost estimate for the Phase 1 expansion to 21 mgd. The opinion of cost is conceptual and is provided as a cost for the Agency s use in planning. These costs are presented with an escalation factor to an assumed construction midpoint of 2012, and includes 30 percent prorate to account for unidentified items. Engineering services are assumed to be 25 percent of construction cost and include design, construction management, and engineering services during construction. Pilot- or plant-scale testing; CEQA, and California Department of Public Health (CDPH) permitting; special inspection; materials testing; water quality testing; and the Agency s administrative, legal and funding costs are not included in the estimates. Table 4-1 Conceptual Cost Estimate for Phase 1 Expansion to 21 mgd (18 mgd firm) Convert to Direct Filtration (21 mgd) and Expand Conventional Treatment (6 mgd) Raw Water Pipeline Flocculation Basins/Mixers (21 mgd) Pumped Rapid Mix Two Settling Basins (6 mgd) $5,200,000 Raw Water Pump Station Expand to 14.5 mgd firm (Phase 1) Expand to 20 mgd firm (Phase 1A) $480,000 $170,000 Filters $4,300,000 High Service Pump Station and UV Disinfection System $3,600,000 Chemical Systems $1,950,000 Residuals Handling $760,000 Construction Cost $16,400,000 Escalation to Construction Midpoint (24%) $3,900,000 Escalated Construction Cost $20,300,000 Engineering Cost (25%) $5,100,000 Total Phase 1 Project Cost $20,400,000 A 22

31 Appendix A Greenhouse Gas Analysis Background A 23

32 Greenhouse Gas Analysis CDM prepared a preliminary estimate of greenhouse gas (GHG) impacts from the proposed improvements. The purpose of preparing a preliminary estimate of GHG impacts for the Improvements Project is to quantify GHG production and determine if the GHG emissions approach or exceed 7,000 metric tons of carbon dioxide (CO 2) /year, the significance threshold set by the California Air Resources Board (CARB) for compliance with CEQA. GHG emissions above this threshold will be considered a significant environmental effect and will need to be mitigated. This threshold is explained more at the web link below: On April 30, 2009 CDM spoke with Gail Williams, an Air Quality Planner at the Butte County Air Quality Management District who reported that they anticipate receiving guidance on a GHG significance threshold for CEQA by the end of Methodology To estimate the CO 2 emissions for the MRWTP Improvements Project, CDM first estimated the electrical demands of the recommended improvements described in the report. The total estimated electrical demands and assumptions for the project are shown in Table A-1. A 24

33 Table A-1 MRWTP Electrical Load Calculations From 2008 PG&E Bill, taking into account 566 kw solar array WTP Power Use June May ,000 kw Notes 566 kw Array PV production data ,000 kwh/yr ,000 kwh/yr ,000 kwh/yr ,000 kwh/yr Average of ,000 kwh/yr Total current WTP power consumption 1,300,000 kwh/yr Current capacity Phase 1 1,600,000 kwh/yr 18 mgd firm Difference 300,000 kwh/yr Phase 1 additional power Phase 2 2,300,000 kwh/yr 25.4 mgd firm Difference 670,000 kwh/yr Phase 2 additional power Additional Unit Power Usage for UV 1 kw/mgd Assumed UV power use Total Annual Unit Power 8,800 kwh/mgd/yr Phase 1 UV 160,000 kwh/yr 18 mgd firm Phase 2 UV 65,000 kwh/yr add 7.4 mgd Phase 1 Total 470,000 kwh/yr 18 mgd plus UV Phase 2 total 730,000 kwh/yr 25.4 mgd plus UV Total 1,200,000 kwh/yr For both phases The estimate of electrical demands starts with the current electrical demand for the plant at a current capacity of about 14.5 mgd. To estimate the overall additional electrical demands at 18 and 25.4 mgd, the current power use is simply scaled up from the current kwh/year/mgd. In addition, the power demand of adding UV treatment is conservatively estimated to be 1 kw/mgd at 18 and 25.4 mgd. UV vendors Trojan and Calgon were contacted for an estimated power demand for equipment conceptually designed to treat the plant effluent at these two rates and power demands were slightly less than 1 kw/mgd for all the alternatives considered A 25

34 (both low and medium pressure systems). This estimate of electrical demand should not be used for sizing electrical equipment since it is overly conservative. Next, an estimate of GHG emissions was calculated. The emissions of the three primary GHGs- CO 2, CH 4 (methane) and N 2 O (nitrous oxide), averaged for all California utility power sources are documented and reported in pounds emitted per kwh of power generated by the utility. These values, along with factors for how CH 4 and N 2 O behave in the atmosphere as compared to CO 2 (known as Global Warming Potentials), allow the total CO 2 equivalent emissions to be calculated for the power demand of the MRWTP improvements project, as shown in Table A-2. A 26

35 Table A-2 CO2 Emissions Calculations for MRWTP Power Use of MRWTP Improvements 1,200,000 kwh/year 1,200 MWh/year California Electric Power Emissions (Note 1) CO lb/mwh CH lb/mwh N2O 0.01 lb/mwh Emissions for MRWTP Improvements CO2 870,000 lb/year CH lb/year N2O 9.71 lb/year Global Warming Potentials (GWP) To get CO2 Equivalents CO lb CO2 CH lb CO2 N2O lb CO2 Emissions for MRWTP Improvements CO2 870,000 lb CO2/yr CH lb CO2/yr N2O 3, lb CO2/yr Total 871, lb CO2/yr Convert to metric tons 1.00 metric ton 2205 pounds Total CO2 emissions from MRWTP Improvements 395 metric tons CO2/year CARB Interim CEQA Threshold for Industrial Projects 7,000 metric tons CO2/year Note 1: CA electric power emissions are from egrid2007, Version 1.1, December 2008 (Year 2005 Data) The increased power demands for the project are well below the CARB threshold. A very conservative (high) power use is assumed for this calculation. The values used for GHG emissions from California utilities are conservative. Values from egrid2007 (Emissions and Generation Resource Integrated Database) are used A 27

36 because this is a convention for GHG emissions calculations, and egrid uses 2005 data averaged for the entire state. If more recent data were available, and only PG&E was taken into consideration, CO 2 emission levels would be lower. Results The conservative estimate of the additional power demands for the MRWTP improvements is 1,200,000 kwh/year and corresponds to an estimate of 395 metric tons of CO 2 equivalents emitted per year to the atmosphere. The GHG estimate for the MRWTP project is well below the interim significance threshold of 7,000 metric tons/year of CO 2 set by CARB for compliance with CEQA. Power demands are estimated to be 60 to 90 percent of the total source of GHG emissions for the project. Therefore a full accounting of cumulative GHG emissions for the entire MRWTP improvements project, which would take into account emissions from other sources such as construction equipment, is also expected to be well below the threshold. A 28