Technical Memorandum CONTENTS

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1 6500 SW Macadam Avenue, Suite 200 Portland, Oregon Tel: Fax: Technical Memorandum Prepared for: City of Medford, Oregon Project Title: New Cogeneration and Gas Treatment Predesign and Design Project No.: Subject: Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Date: July 20, 2010 To: From: Copy to: Tom Suttle, WRD Construction Manager Dan Laffitte, Project Manager, Brown and Caldwell Christopher Muller, Ph.D., Project Engineer, Brown and Caldwell Prepared by: Christopher Muller, Ph.D. CONTENTS Executive Summary... 3 Introduction... 5 Substrates for Co-Digestion... 6 Survey-Based Estimation Limited Market Analysis FOG Receiving Facility Sizing Parameters FOG Delivery Methods Process Implications of Grease Acceptance Estimate of Co-Digestion Process Parameters FOG Receiving Facility FOG Program Net Present Value Analysis FOG Impacts to Engine Size FOG Capital Funding Opportunities Net Metering Agreement Peak Use Elimination Alternatives Conclusions and Recommendations References p:\ medford cogen design\fog analysis\tm\medford fog tm - final docx

2 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis LIST OF FIGURES Figure ES-1. Influence of tipping fees on the 20-year NPV and payback period of FOG receiving at the RWRF... 4 Figure ES-2. Payback periods for various FOG program scenarios... 5 Figure 1. Volumetric biogas production from anaerobic digesters receiving different substrates (European & U.S. facilities)... 6 Figure 2. Basic flow schematic of BTA process for the preparation of food scraps for digestion and the raw and final product... 8 Figure 3. Schematic of typical grease interceptor for generators (restaurants, etc.)... 9 Figure 4. Impact of FOG on different elements of wastewater collection Figure 5..Impact of poor mixing on the active volume of an anaerobic digester Figure 6. Influence of VSr and biogas yield on biogas production relative to report values for Medford Figure 7. Contaminants in brown grease from a pilot test using chopper pumps as the mixing pump Figure 8. Basic flow schematic of FOG receiving station with separate receiving and digester loading capabilities Figure 9. Influence of tipping fees on the 20-year NPV and payback period of FOG receiving at the RWRF Figure 10. Payback periods for various FOG program scenarios LIST OF TABLES Table ES-1. Summary of Estimated Grease Production from Footprint Recycling... 3 Table ES-2. Estimated Biogas Production from RWRF with and without FOG Addition... 4 Table 1. Summary of Medford RWRF Service Area Populations... 6 Table 2. Summary of Potential Food Waste in the Medford RWRF Service Area a... 7 Table 3. Summary of Characteristics of Different Liquid Wastes... 9 Table 4. Estimated Total Grease Available in the Medford RWRF Service Area Table 5. Summary of Grease Haulers Contacts Identified in the Limited Market Analysis Table 6. Summary of Estimated Grease Production from Footprint Recycling Table 7. Summary of FOG Flows from Various Sources or Estimating Options Table 8. Summary of Reported Tipping Fees for Various Disposal Routes Table 9. Cost Elements of Hauled Waste Program Operated by the City of Medford, Oregon Table 10. Estimated Ammonium-N Release from FOG and Wastewater Sludges from Tacoma, WA Table 11. Projected Loadings to RWRF Digestion Process Table 12. Summary of Digester Process Capacity Parameters for Medford RWRF Table 13. Hydraulic Impacts of FOG Addition to Medford Digesters Table 14. Impact of FOG Load Addition on Digester Organic Loading Rate Table 15. Estimated Biogas Production from RWRF with and without FOG Addition Table 16. Projected Gas Flows and Engine-Generator Output with and without FOG Table 17. Funding Potential

3 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Executive Summary This Technical Memorandum (TM) presents the feasibility analysis performed for a fats, oils, and grease (FOG) program that would increase energy production at the City of Medford Regional Water Reclamation Facility (RWRF). Results from an analysis of a net metering agreement and electrical peaking analysis are also documented herein. The analysis of the FOG system is summarized below and detailed in subsequent sections. There are two main categories of FOG brown grease or yellow grease. Brown grease is the material that is typically collected in grease interceptors and is considered a waste or nuisance material as it can clog sewers and foul equipment in the treatment process. Yellow grease includes fryer oils and other such materials that are typically collected and stored by restaurants. Yellow grease is highly valued by both the rendering and biodiesel industries, as it comprises the raw material for their respective processes. Two methods were used to estimate the quantity of FOG that could be available to the RWRF. Censusbased population information and national survey information from the National Renewable Energy Laboratories were used to estimate brown and yellow grease quantities of 777 and 516 tons per year, respectively. The second method used market survey information collected during execution of the FOG analysis phase of the project. The survey information suggested that the amount of FOG available would vary, based on inclusion or exclusion, of loads from the Rogue Valley Medical Center. Table ES-1 lists the potential variation. Table ES-1. Summary of Estimated Grease Production from Footprint Recycling Bulk grease (lb/quarter) Neat grease (lb/quarter) a Neat grease (lb-grease/day) b VS content (lb-vs/lb-grease) c VS load (lb-vs/day) Low range flow (gpd) d High range flow (gpd) e High range (with 300, ,000 2, , ,960 RVMC load) Low range (without 112,000 84, ,100 RVMC load) a. Assumes 91 days per quarter. b. Assumes 25 percent water content in bulk grease per Footprint Recycling interview. c. Assumed value based on literature-reported values. d. Assumes 75 percent solids content based on Footprint Recycling interview. e. Assumes 10 percent solids content based on literature-reported values. The three basic parameters that could be used to size a FOG-receiving facility for the RWRF were the limited phone survey, the population-based FOG estimate, and the process limits of the digestion system. A FOGreceiving station based on process limits would result in a station that greatly exceeds the amount of FOG available to the RWRF. For this analysis, a FOG-receiving station based on two tanks with a combined capacity of 12,000 gallons was assumed, which allows for process flexibility and growth through approximately The three methods of FOG delivery considered were private haulers, preferred private haulers, and Cityoperated haulers. There would be a significant capital investment required for creation of a City hauler program, along with increased staffing and maintenance costs. Additionally, a City hauler program would result in direct competition with private haulers already providing services in the area. Most local haulers expressed interest in participation in a FOG program. For these reasons, a City hauler program was not recommended. 3

4 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Impacts to the existing RWRF processes and current and future gas projections were considered as part of the analysis. While there is sufficient process capacity, a new mixing system should be installed to reduce foaming potential and to ensure that the FOG is well dispersed throughout the digesters. The gas projections associated with the FOG addition are summarized in Table ES-2. It should be noted that the amount of gas currently being generated by the RWRF was lower than expected by both Brown and Caldwell and RWRF staff. Table ES-2. Estimated Biogas Production from RWRF with and without FOG Addition Parameters Units Wastewater sludge biogas production Calculated biogas production 304, , ,630 ft 3 -biogas/day FOG associated biogas Calculated biogas production 37,311 45,795 54,381 ft 3 -biogas/day Total biogas calculated 342, , ,011 ft 3 -biogas/day Figure ES-1 illustrates the 20-year net present value (NPV) based on assumptions and data presented in subsequent sections of this TM. Figure ES-3 also illustrates the effect of tipping fees on the 20-year NPV. Not until the tipping fee approaches $0.17 per gallon does the receiving facility and mixing upgrade switch to a positive NPV. Figure ES-1. Influence of tipping fees on the 20-year NPV and payback period of FOG receiving at the RWRF (Note: positive NPV is a benefit to the City under this analysis and clear data point(s) represent greater than 20-year payback, assumes incremental capital cost of cogeneration is included along with sludge receiving station costs and mixing upgrade costs.) The discounted payback period is greater than 20 years, primarily due to the inclusion of the upgraded mixing system that has a capital cost of $1.9 million. 4

5 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis If a FOG program was initiated, the cogen engine size recommended in the energy planning project would likely increase to the next available engine size. However, the less than expected gas production should be further investigated before the engines size is finalized for design. Two external funding sources are established for the FOG project being considered. The State of Oregon s Business Energy Tax Credit (BETC) program funds 33.5 percent for municipal renewable energy projects and the Energy Trust of Oregon, through its Biopower Program, provides funding for above-market costs of energy. Figure ES-4 illustrates four project scenarios considered as part of the analysis. An initial capital cost is shown in the year 2011, and the net revenue from electricity is shown over the 20-year life of the project using the same assumptions defined in the present worth analysis. Figure ES-2. Payback periods for various FOG program scenarios Introduction The RWRF discharges effluent that meets standards defined by the Oregon Department of Environmental Quality. As part of that process the RWRF generates primary and secondary sludges which are anaerobically stabilized prior to storage in lagoons, air drying, and eventual land application. The existing mesophilic digestion process produces Class B biosolids. A by-product of the mesophilic digestion process is biogas, which is composed primarily of methane and carbon dioxide. Typically a mesophilic digester generates anywhere from 12 to 18 cubic feet (ft 3 ) of biogas per pound (lb) of volatile solids (VS) destroyed. Under these conditions there is typically sufficient gas to meet the heating needs for the plant and in some cases cogenerate additional heat and power using internal combustion engines or microturbines. 5

6 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Recent history suggests that power costs are becoming more volatile with increased demand and resource scarcity, which has led to a move toward more sustainable energy production efforts. Wastewater treatment plants (WWTPs) with anaerobic digestion are positioned to take advantage of this shift in the market through the use of spare capacity in the digestion process and the addition of co-digestion substrates such as fats, oils, and grease (FOG); pulped food scraps; and dissolved air flotation (DAF) floats from food processors. Codigestion substrates are an excellent means of effectively utilizing excess capacity as the substrates typically have a higher methane potential and greater degradability than the sludge generated during wastewater treatment. Figure 1 compares the typical gas generation profile of United States facilities digestion sewage sludge and those in Europe practicing co-digestion as measured by ft 3 -biogas/ft 3 -digester volume. The data show that co-digestion dramatically increases the biogas-generating capabilities of the process. Figure 1. Volumetric biogas production from anaerobic digesters receiving different substrates (European & U.S. facilities) While the benefits of co-digestion are not new, being reported by facilities such as East Bay Municipal Utility District (EBMUD) and Millbrae, California, it has been slow to gain acceptance. Therefore, utilities implementing early have a distinct advantage when it comes to attracting haulers and substrate sources in the region. This study is intended to provide a high-level analysis of the feasibility of implementing a hauled fats, oils, and grease program at the RWRF. Substrates for Co-Digestion The following section provides a discussion of substrate types most frequently used by WWTPs for biogas production. Food Wastes While this study focuses specifically on FOG, it is worth noting that food wastes or the organic fraction of municipal solid waste represents another large reservoir available to utilities wishing to increase biogas production. Population data, illustrated in Table 1, were used to estimate both FOG and food waste potential quantities. The populations included in the table represent incorporated areas served by the Medford RWRF. Unincorporated Jackson County was excluded. Table 1. Summary of Medford RWRF Service Area Populations 6

7 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis City Population City of Medford 73,212 Central Point 16,503 Jacksonville 2,181 Phoenix 4,402 Talent 6,215 Eagle Point 8,302 White City 5,466 Total 116,281 Source: 2008 U.S. Census data Using the data from Table 1, an estimate of total potential food waste in the service area can be made assuming a similar compositional and production rate to that observed for Metro Vancouver, British Columbia. Table 2 provides a summary of the results of the annual food waste generation estimate for the Medford RWRF service area. Table 2. Summary of Potential Food Waste in the Medford RWRF Service Area a Residential material Food waste type Value c Units Source Fruits and vegetables lb/person-yr TRI (2004) Meat, dairy, fats, and other lb/person-yr TRI (2004) Total residential annual estimate b 3,980 tons/yr Commercial material Fruits and vegetables lb/person-yr TRI (2004) Meat, dairy, fats, and other lb/person-yr TRI (2004) Total commercial annual estimate 6,530 tons/yr Total combined annual estimate 10,510 tons/yr a. Assumes per capita production rates similar to Metro Vancouver along with similar composition of municipal solid waste. b. Based on population estimate from Table 1 and assumed access to material from the service area. c. Aeration values from Technology Resources Inc., North Vancouver, B.C. Solid Wastes Composition Study for Greater Vancouver Regional District, January 14, It should be noted that the estimate in Table 2 is based on 100 percent capture of the materials available. Actual capture rates are expected to be much lower and commercial-based sources would be recommended as a starting point for any program due to their available quantity and higher quality. Figure 2 illustrates the BTA process, which is an example of a typical process to convert collected food wastes to a product that is suitable for anaerobic digestion. Before and after photographs of the food waste are included in the figure. 7

8 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis (a) Food waste processing flow schematic (b) Raw food scraps (c) Hydropulped food scraps Hauled Liquid Wastes Figure 2. Basic flow schematic of BTA process for the preparation of food scraps for digestion and the raw and final product Another future co-digestion substrate source that RWRF could consider is hauled liquid wastes, which can come in a range of volumes and compositions. Examples of liquid wastes can include spent wine, beer, and soda; DAF float from food manufacturing or rendering; and high-strength liquids such as tallow liquor. Table 3 provides a summary of different liquid biochemical characteristics of some of these liquid wastes. 8

9 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Table 3. Summary of Characteristics of Different Liquid Wastes Waste COD (mg/l) TKN (mg/l) COD/N Source Soda 135, ,350/1 Flippin et al. (2007) Diet soda /1 Flippin et al. (2007) Fluid milk waste 160,000 5,000 32/1 Flippin et al. (2007) Acid whey 82,000 1,400 59/1 Flippin et al. (2007) Egg wash water 1,500 (mg-bod/l) 384 4/1 Brown and Caldwell files Tallow tank liquid 239,000 12,900 19/1 Brown and Caldwell files DAF sludge, chili, soup, and salad dressing 285,000 36,300 8/1 Brown and Caldwell files Confectionary waste 1,830,000 25,700 71/1 Brown and Caldwell files Typical Untreated Wastewater /1 Metcalf & Eddy, 3 rd Edition FOG 2,960 (g-cod/kg) 5.1 (g-tkn/kg) 580/1 Kabouris et al. (2008) Fats, Oils, and Grease The main focus of this report FOG typically falls into one of two categories: brown grease or yellow grease. Brown grease is the material that is typically collected in a grease interceptor (Figure 3). Yellow grease is typically fryer oils and other such materials that are collected in containers behind restaurants. Yellow grease is a highly valued commodity to both the rendering and the biodiesel industry, as it is the raw material for their processes. In some cases restaurants are being paid for their yellow grease. Figure 3. Schematic of typical grease interceptor for generators (restaurants, etc.) Brown grease is typically considered a waste or nuisance material as it can clog sewers and foul equipment in the treatment process. Figure 4 shows the negative effects that grease accumulation can have on piping and other elements of the conveyance system. 9

10 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Figure 4. Impact of FOG on different elements of wastewater collection Yellow grease is typically collected by rendering companies and/or biodiesel companies. The increasing commodity values of this product due to increased utilization makes its capture difficult for WWTPs, as some services are willing to pay for the product rather than charge a fee. Some biodiesel manufacturers have reported theft of yellow grease from restaurants. Survey-Based Estimation The total amount of brown and yellow grease that can be accepted by a facility will be limited by either supply or demand from the utility. Supply-side estimates of availability can be made through market analysis, or through the use of national survey data. In 1998 the National Renewable Energy Laboratories (NREL) issued a report on a survey conducted in the U.S. on the total amount of brown and yellow grease generated in select cities. On average, each person generates approximately pounds of brown grease annually and 8.87 pounds of yellow grease, through normal activities. For a service area the size of Medford, assuming a population of 116,281 individuals, an estimate for brown and yellow grease can be made: 777 and 516 tons per year, respectively. Table 4 provides a summary of the calculated total grease potential of the Medford RWRF service area, using Table 1 data and the Wiltsee (NREL) projections. 10

11 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Table 4. Estimated Total Grease Available in the Medford RWRF Service Area Value Units Brown grease Production rate lb-grease/person-yr Total brown grease annual estimate 777 ton-grease/yr Yellow grease Production rate 8.87 lb-grease/person-yr Total yellow grease annual estimate 516 ton-grease/yr Total combined annual estimate 1,292 tons/yr As noted with food waste, the likely capture rate will be significantly lower than the total amount available. The NREL survey accounted for grease in the raw influent to the plant as well as hauled materials. Capture of grease from individual residences is highly unlikely, as is significant capture of yellow grease from restaurants. Some utilities with fairly extensive source control measures have reported capture rates of only 6 to 7 percent of the total theoretical quantity estimated for their service areas. However, using a large radius haulers may provide sufficient quantities of materials. Limited Market Analysis A limited market analysis was conducted as part of this feasibility study to understand the market and potential participants. The market analysis was limited to haulers and select restaurant and food processors in the region. Table 5 provides a summary of the entities contacted as part of this effort. Table 5. Summary of Grease Haulers Contacts Identified in the Limited Market Analysis Contact name Company Phone number address Company description Rick, Southwest Oregon lead North State Rendering (Oregon Region) n/a Rendering company which accepts brown grease Chris Ottone, President North State Rendering (headquarters: CA) n/a Rendering company which accepts brown grease Andrew Cooper, President Footprint Recycling info@footprintrecyling.com Biodiesel and grease hauler John Hayes, Owner A-Affordable Royal Flush n/a Septage and grease hauler North State Rendering North State Rendering collects brown and yellow grease in northern California and southern Oregon. Some material is processed through its rendering program while other materials are digested to generate biogas and energy. North State reported that it operates a digestion-to-biogas facility, does not require any further processing capability, and would not be interested in participating. Footprint Recycling Footprint Recycling is a biodiesel company operating in northern California and also providing services to the southern Oregon region. Footprint Recycling currently collects both brown and yellow grease as part of its suite of services. Yellow grease is processed as part of its biodiesel manufacturing program. The glycerol generated as part of Footprint s biodiesel program is converted to soaps and cleaning solutions for sale in the region. 11

12 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis The brown grease collected is brought to the Clear Water Technologies facility in Merlin, Oregon, for disposal, which currently consists of large drying beds and subsequent disposal in landfills. Footprint Recycling generates approximately 300,000 pounds of bulk grease every quarter when collecting from Rogue Valley Medical Center (RVMC). Without RVMC, Footprint Recycling collects approximately 112,000 pounds of bulk grease per quarter. Footprint Recycling estimated 25 percent water content in its bulk grease. Footprint is currently charged a fee of $0.12 to $0.15 per gallon of material discharged to Clear Water Technologies and approximately $0.10 per gallon for disposal at EBMUD. Table 6 provides a summary of the range of loads reported by Footprint Recycling along with calculated neat grease estimates based on the reported water content. High range (with RVMC load) Low range (without RVMC load) Table 6. Summary of Estimated Grease Production from Footprint Recycling Bulk grease (lb/quarter) Neat grease (lb/quarter) a Neat grease (lb-grease/day) b VS content (lb-vs/lb-grease) c VS load (lb-vs/day) Low range flow (gpd) d High range flow (gpd) e 300, ,000 2, , , ,000 84, ,100 a. Assumes 91 days per quarter. b. Assumes 25 percent water content in bulk grease per Footprint Recycling interview. c. Assumed value based on literature-reported values. d. Assumes 75 percent solids content based on Footprint Recycling interview. e. Assumes 10 percent solids content based on literature-reported values. Footprint Recycling President Andrew Cooper indicated that a centrally located disposal location, such as Medford, would be beneficial to his company and that it would be willing to participate in the program if it made sense for both Medford and Footprint Recycling. Footprint Recycling also noted the capability and willingness to collect additional substrates from sources other than grease interceptors as long as the material was in liquid form. A-Affordable Royal Flush A-Affordable Royal Flush was contacted on several occasions. The receptionist stated that the owner would call back to discuss specifics. The owner was unresponsive and after multiple failed attempts to make contact, the source was abandoned. The receptionist indicated that the company would be interested in a centrally located facility as it also hauls to Merlin, Oregon, for ultimate disposal. It is recommended that the City staff contact this hauler directly to determine the overall viability of its participation. The receptionist stated that the company has been contacted by several different companies requesting similar information. FOG Receiving Facility Sizing Parameters The three basic parameters that can be used to size a FOG receiving facility for the RWRF are the limited phone survey, the population-based FOG estimate, and the process limits of the digestion system. Table 7 presents a summary of the different sizing criteria data that could potentially be used including additional assumptions. 12

13 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Table 7. Summary of FOG Flows from Various Sources or Estimating Options Units Assumptions and notes 7-day per week receiving Footprint Recycling (with RVMC) c 2, gpd Based on information provided by source, assumes specific weight of water Footprint Recycling (without RVMC) c 1, gpd Based on information provided by source, assumes specific weight of water Population-based estimate 5,100 6,100 a 7,200 b gpd Approximately 4,300 lb-ts/day, 10 percent solids, specific weight equal to water Maximum process capacity 14,800 17,800 21,200 gpd 30 percent of VS load at average annual conditions, 10 percent solids, specific weight equal to water 5-day per week receiving Footprint Recycling (high range) c 4, gpd Based on information provided by source, assumes specific weight of water Footprint Recycling (low range) c 1, gpd Based on information provided by source, assumes specific weight of water Population-based estimate 7,100 8,500 10,100 gpd Approximately 4,300 lb-ts/day, 10 percent solids, specific weight equal to water Maximum process capacity 20,720 24,900 29,700 gpd 30 percent of VS load at average annual conditions, 10 percent solids, specific weight equal to water a. Assumes that FOG solids production increases in the same proportion as wastewater solids over the same period of time : 18.5%. b. Assumes that FOG solids production increases in the same proportion as wastewater solids over the same period of time : 18.8%. c. Long-term projections for private companies were not predicted in this case. Factors that also need to be considered include digester loading and receiving schedules, as they will impact the size of the facility and the gas production to the cogeneration facility. Additionally, prior to detailed design of a FOG program, non-economic factors should also be considered such as a reduced carbon footprint associated with a shorter haul distances. For this analysis it is assumed that the RWRF will not want to operate the receiving facility on the weekends but will want to maintain a FOG load to the digesters over the weekend, to provide more consistent gas production. Based on this assumption the receiving schedule will be 5 days per week with loading to the digesters 7 days per week, resulting in a differential flow rate for facility sizing. It is also assumed that the facility will be sized to meet 2020 flows and loads. This was assumed to reduce the risk of a stranded investment. Sizing for 2030 adds an inherent risk to the project, in that it is difficult to project with any certainty the market conditions at that time. Furthermore, a 2020-sized facility can be designed to be modular and allow for expansion sooner or later, depending on market conditions. The data in Table 7 indicate that using a portion of the population-based grease estimate that slightly exceeds the limited market survey performed will provide a reasonably sized facility. It should be noted that capture of all the grease estimated by the population-based factors is not expected. Basing the size of the receiving station on a fraction of the population-based projections provides some flexibility on nominal tank size as well as RWRF s ability to accept other material or operate in other modes. To illustrate the difficulty in capturing all the population-based grease projected, a recent article in the Seattle Post-Intelligencer (January 19, 2010) reported that of 2,600 food service establishments, which include bakeries, groceries and restaurants that seat more than 12 people, only 1,000 have pre-treatment devices, according to SPU (Seattle Public Utilities) estimates. Based on those numbers, only 38 percent of the total brown grease generated is available for capture by conventional measures such as pump trucks. Metro Vancouver, using the same population-based estimate used in Table 4 and reported annual grease hauler 13

14 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis production from its pretreatment division, is capturing approximately 6.7 percent of the potentially available material, assuming brown grease hauling only. Because of the high potential load from Footprint Recycling during periods when it is servicing the RVMC, and considering capture rates of other treatment systems, we have assumed an aggressive 47 percent capture rate for the program as a basis for the initial facility. This percentage is a result of selection of a tank size of 6,000 gallons, which would accommodate the higher loading rates with RVMC included and allow for growth and additional volume for process and receiving flexibility. Based on this assumption the facility would require 12,000 gallons of tank volume to allow for accepting FOG at 5,600 gallons per day (gpd) 5 days per week and loading to the digesters at a maximum of 4,000 gpd. This is roughly based on year 2020 loading. Two 6,000-gallon tanks provide process protection as well as flexibility during startup. FOG Delivery Methods The delivery of FOG to the RWRF can come from one of the following three sources: private haulers preferred private haulers City-operated hauling. Private haulers are in the business of collecting and disposing of grease from grease traps. This material is sometimes co-collected with septage. In such cases it is recommended that the hauler discontinue cocollection, as septage is not desirable. The primary cost constraints associated with using private haulers are reliability and price competition. As previously reported, Footprint Recycling pays approximately $0.12 to $0.15 per gallon to dispose of material at the Clearwater Services, Merlin facility. Other facilities report a variety of different rates as summarized in Table 8. Wastewater utilities EBMUD Millbrae, California Oxnard, California Riverside, California a SBSA Watsonville, California Metro Vancouver Merlin, Oregon Hauled sludges/septage Renton, Washington Landfill rates charged or reported Rendering waste a. Riverside is anticipating raising its tipping fee. Table 8. Summary of Reported Tipping Fees for Various Disposal Routes Agency Brown grease tipping fee $0.11 per gallon non-concentrated $0.15 per gallon concentrated $0.14 per gallon + $25 per truckload $0.07 per gallon $0.01 per gallon $0.10 per gallon $0.04 per gallon $0.25 per gallon (converted to USD at 1.05 CAD/USD) $ per gallon $0.102 per gallon, $200 per truck per year fee, $50 per truck setup fee $28 per ton, (22% dewatered FOG) For the RWRF to be successful, it must charge a competitive rate that attracts haulers to the facility but that also is sufficiently high to cover operating costs and debt servicing, if required. If possible the RWRF should try and set contracts with haulers to provide stability in the supply of FOG or other hauled wastes. 14

15 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis A second alternative would be to use a commercial hauler with preferred hauler status. This hauler would dispose of materials exclusively at the RWRF at a discounted rate. Some preferred hauler contracts prohibit other haulers from using the facility, providing a competitive advantage to the exclusive hauler. Some companies will provide capital to construct the receiving station, which the City would own. The hauler providing the capital would receive deep discounts on the rate charged and might also ask for exclusive rights to the facility for a given period of time. This model has proven to work in some areas but it would likely involve an outside company not in the Medford region, which would establish a fourth hauler in the region. The final alternative would be for the City to start its own pumping and hauling program. The primary benefits would be that the City would have control of the program in its entirety, removing any risk associated with commercial hauler closing, moving, or no longer using the facility. The drawbacks are primarily associated with capital and operations and maintenance costs. As a minimum the RWRF would assume an investment in several new pumper trucks, drivers, clerical staff, and maintenance equipment and staff. The rate structuring would be based on the number of facilities from which the City would collect grease in order to cover the cost of the receiving station and the hauler program costs. In such a case the City would also become a direct competitor with the local private haulers. The cost of the program could be significant, depending on how much of the market the RWRF wants to capture and what range the trucks are intended to cover. A 2,200-gallon pump truck costs approximately $85,000. Minimal staffing estimates along with truck capital costs are provided in Table 9. Given the fact that there are commercial haulers in the region that have indicated a willingness to use a facility located at the RWRF, it is likely that a City-operated program would not be necessary. The City may want to further develop the concept as insurance against haulers leaving or going out of business or to further fill any perceived service gaps in the collection system. Table 9. Cost Elements of Hauled Waste Program Operated by the City of Medford, Oregon Capital investments Quantity Unit cost Total cost Notes Pumper truck (each) 2 $85,000 $165,000 Value Provided by Keevac Industries, Inc. Staffing costs Parameters Number Rate ($/hr) Total ($/year) Notes Full-time driver/operator 2 30 $125,800 Assumes 2 FTE, at $30 per hour, per Medford staff Clerical support 1 30 $31,200 Assumes 0.5 FTE, at $30 per hour, per Medford staff Program manager 1 30 $31,200 Assumes 0.5 FTE, at $30 per hour, per Medford staff Process Implications of Grease Acceptance The acceptance of grease at a WWTP is not particularly difficult to execute if appropriate material handling systems are put in place, but some care must be taken to ensure that the process continues to operate as expected. The following section presents a discussion of loading, toxicity, synergistic effects, and methane potential for FOG digestion. Loading Limitations The addition of grease to digesters is not limitless. FOG contains fats which, when hydrolyzed, form glycerol and long-chain fatty acids (LCFAs). LCFAs are the primary substrate for the microorganisms to convert to methane through β-oxidation and hydrogenotrophic methanogenesis. However, if hydrolysis exceeds methane formation the accumulation of LCFAs can lead to toxicity issues for the digester. LCFAs at high concentrations can inhibit the digestion process. Research by Suto et al. (2005) suggests a limit of FOG addition for anaerobic digesters of 30 percent by load on a volatile solids basis. 15

16 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Synergistic Effects The addition of FOG has been reported to improve not only gas production, due to its higher methane potential, but also sludge solids destruction. Full- and bench-scale studies have noted that when conducting a solids balance on digesters receiving high loads of FOG, the amount of biogas produced stoichiometically does not match what should be produced if the sludge and FOG were digested separately. It has been postulated that the addition of FOG improves digestion through an improvement in the carbon-to-nitrogen (C/N) ratio in the digesters, as FOG is relatively low in nitrogen content relative to the sludge, thus shifting the ratio in a more ideal direction. Other effects may have to do with the biochemical conditions in the digester. Typically these impacts are observed in digesters that receive higher loads of FOG. Secondary Treatment Impacts As previously discussed, FOG typically has a much higher C/N ratio than typical wastewater sludges, which can result in improved digester performance. However, the improved C/N ratio does not translate to a reduction in the nutrients recycled to the secondary system. The higher concentrations of solids associated with FOG, typically percent, are greater than those of sludge, thus increasing the mass of the overall nitrogen load. A recent analysis of FOG substrate from another collection system indicated that the total Kjeldahl nitrogen (TKN) was approximately 10,200 mg-n/kg-fog (22 percent solids) relative to the 1,750 mg-n/kg-sludge reported for the plant (average sludge concentration 3.7 percent solids). Given the approximately five-fold increase in TKN of FOG relative to sludge, one would expect a greater mass release of ammonium-n during degradation on an equivalent volume basis. Table 10 provides a summary of an example of the additional nitrogen load associated with a 1,000-gpd flow of the sludge and FOG material following anaerobic digestion, using data from the facility where it was collected. Table 10. Estimated Ammonium-N Release from FOG and Wastewater Sludges from Tacoma, WA Parameter FOG a Sludge Flow (gpd) Total solids (lb-ts/lb-material) TKN (lb-n/lb-material) Volatile solids (lb-vs/lb-ts) d Volatile solids reduction (VSr) b Total solids flow (lb-ts/day) Total volatile solids load Volatile solids destroyed TKN (lb-n/lb-vs) Nitrogen load from digester (lb-n/day) c a. The FOG material has been partially rendered and dewatered. b. FOG VSr based on work by Kabouris et al. (2008). c. Denotes mono-substrate system; true system FOG would be mixed with sludge. d. Lower volatile content of FOG due to partial rendering. Based on the data in Table 10 it is expected that the addition of FOG will increase the observed nitrogen load from the digesters due to the high concentration of solids. If FOG is received at lower concentrations (10 15 percent), then it would be expected that the ammonium-n release would be reduced as there is less material per unit volume. 16

17 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis The other macronutrient of concern is phosphorus (P), which for the same samples described above produced very similar mass-based concentrations (841 mg-p/kg-fog and 738 mg-p/kg-sludge). The increased concentration of FOG would result in a net increase in the release of P from the system, as was observed with the nitrogen species. However, phosphorus, especially in the form of phosphate, is highly reactive and can precipitate with several different cations (iron, calcium, and magnesium); thus a direct release model is difficult to use. If phosphorus is a concern, the City may want to further investigate the chemical composition of the substrates provided. It is also worth noting that conducting chemical analysis on new co-digestion substrates is beneficial. Not only do ammonium-n and phosphorous contribute to the nutrient load on the secondary system, but depending on the chemistry of the digestion system, specifically magnesium content, it could also exacerbate or create a struvite problem. It is recommended that the City conduct some basic analysis on substrates it plans to accept to ensure that the process is not negatively impacted. Acclimation Acclimation is critical to the initial and long-term success of a FOG acceptance program. The addition of high concentrations of FOG to a digester typically causes foaming and/or process upset when done on a periodic basis. These conditions are a result of not having the right population present in the digester to efficiently degrade the added substrate. However, if a FOG program is allowed to start at low loading rates and increase with time, the digester can acclimate to the new substrate and be able to accept much higher loads than initially possible. It should be noted that acclimation is not unique to FOG; other substrates have exhibited similar behavior in digesters. Adequate Mixing The addition of FOG to digesters is beneficial when the process is capable of converting the material to biogas. However, in addition to the loadings and the biology, the physical conditions must also be adequate. Poor or inadequate mixing could result in substandard performance or increased operations and maintenance costs for the system overall. FOG is hydrophobic in nature and thus readily separates from water, typically floating on the surface where it would likely be poorly accessible to the microorganisms in the bulk liquor. Under ideal mixing conditions these hydrophobic solids (FOG) are entrained into the bulk liquid through the downdraft created by the mixing system. If inadequate mixing occurs in a digester receiving FOG, formation of a floating scum layer could lead to other operational problems, especially foaming. The formation of a foaming scum layer can be difficult to combat in a closed system unless mixing is improved or surface withdrawal is practiced. Furthermore, gas mixing can exacerbate foaming in digesters and in the absence of surface withdrawal, uncontrolled foaming can enter the gas system. Figure 5 illustrates how inadequate mixing can impact the active volume of a digester. Hydrophobic materials, FOG, will increase the amount of loss in the area noted as the scum layer in Figure 5. Ensuring adequate mixing is critical to the long-term success of a FOG digestion program and maximum use of digester active volume. It should also be noted that loss of active volume can result in a reduction in actual hydraulic retention time (HRT) as well as increases in observed loading rates. 17

18 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Scum layer Active volume Grit Total volume Scum accumulation Grit accumulation Unmixed volume Debris Active volume Remaining Figure 5. Impact of poor mixing on the active volume of an anaerobic digester Estimate of Co-Digestion Process Parameters As discussed in previous sections, there are several limits to size and scope of a co-digestion program. This section reviews Medford s process data and makes a projection on the amount of FOG that can be accepted along with the additional biogas that could be generated. Anaerobic Digester Capacity The RWRF operates two mesophilic anaerobic digesters in parallel to stabilize raw primary and secondary solids from liquid treatment processes. These digesters produce a digested biosolids product, which is further stabilized in lagoons and the plant s sludge drying beds, meeting the requirements of 40 Code of Federal Regulations (CFR) 503 (503-Regulations). It is assumed that the City of Medford desires to continue to meet Class B biosolids requirements through these processes rather than using other alternatives. Table 11 provides a summary of the average annual, maximum month, and peak 14-day flow and loads to the anaerobic digesters at Medford based on data provided by the City for Data from the period December 2006 through January 2007 was excluded from the analysis as it appeared anomalously high. Plant staff could not explain the high loads during this period and it was agreed that it should not be used. Future loads were projected using the same rate of increase projected for the influent total suspended solids (TSS) as part of the RWRF Facilities Plan update project. The Facilities Plan describes the digestion process limits as all digesters in service with a minimum HRT of 14 days at maximum month flows and loads. Given the fact that sludge lagooning and drying occurs postdigestion, these limits are reasonable. It should be noted that as the digestion process approaches capacity and cleaning needs to occur it is likely that raw sludge will need to be bypassed directly to the lagoons as the HRT will become excessively low for mesophilic anaerobic digestion to continue to operate in a stable manner. If the drying beds are removed the capacity should be reevaluated at peak 14-day load as the digesters will need to meet Class B requirements, without the drying beds. Based on the data in Table 12 and assuming that the active volume of Medford s digesters is 1,451,000 gallons and they are capable of stable operation at a maximum load of 180 lb-vs/1,000-ft 3 -day, the digestion process will reach capacity around 2020, based on sludge production projections. It should be noted that the volume associated with the bottom cone of the digesters was excluded from the active volume calculation. No further active volume reductions that might occur due to poor mixing or grit accumulation were assumed. Assuming that a maximum month condition is the limit for loading, the facility is currently approaching the theoretical limit for mesophilic anaerobic digestion when one digester is taken out of service. Grady et al. 18

19 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis (1999) reported that the theoretical minimum HRT of mesophilic digestion is 10 days. However, 15 days is typically set as the minimum HRT, given the inherent variability in flows and loads in full-scale systems. Table 11. Projected Loadings to RWRF Digestion Process Current Average annual Flow (gpd) 106, , ,000 Total solids load (lb-ts/day) 41,000 49,000 58,000 Total volatile solids load (lb-vs/day) 35,000 42,000 50,000 Maximum month Flow (gpd) 118, , ,000 Total solids load (lb-ts/day) 50,000 60,000 71,000 Total volatile solids load (lb-vs/day) 43,000 52,000 61,000 Peak-14 day Flow (gpd) 122, , ,000 Total solids load (lb-ts/day) 50,000 60,000 71,000 Total volatile solids load (lb-vs/day) 45,000 52,000 61,000 Table 12. Summary of Digester Process Capacity Parameters for Medford RWRF Parameters Current Units Facilities elements Digester diameter ft Operating depth ft Digester volume 3 1,451,628 1,451,628 1,451,628 gallons Digester volume 4 1,451,628 1,451,628 1,451,628 gallons Hydraulic retention time (each) 2 digesters in service Average annual days Maximum month days Peak 14-day load days 1 digester in service Average annual days Maximum month days Peak 14-day load days Organic loading rate Average annual lb-vs/1,000-ft 3 -d Maximum month lb-vs/1,000-ft 3 -d Peak 14-day load lb-vs/1,000-ft 3 -d Several approaches can be used to determine the amount of FOG that a facility will receive, including market surveys and population-based estimates. However, the maximum load is limited by the biology of the system. Without further testing, the volatile load of FOG applied to the digesters should not exceed 30 percent of the volatile sludge load applied from normal wastewater operations. The analysis presented in this memo considers the average annual sludge loading conditions to set the maximum FOG load. Based on the data provided by Medford, the maximum FOG load under current (2008) conditions is approximately 10,500 lb- VS/day as FOG. Assuming a volatile fraction of 95 percent, the total FOG load could be as high as 11,100 19

20 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis lb-ts/day or 14,800 gpd assuming 10 percent solids and a specific weight equivalent to water. This condition would represent the maximum average annual daily load of FOG that could be accepted by Medford, which would be approximately three large tank trucks per day (5,000 gallons each) or five to seven small pumper trucks (2,000 3,000 gallons each). This value is well above the estimated 3,000 gpd reported by Footprint Recycling or anticipated by the population-based estimate and the selected design condition of 4,000 gpd, 7 days per week. This suggests that Medford can actively market and accept additional material to increase biogas production and revenues. If this approach is taken, it is recommended that the substrates be evaluated for degradability, metals, and composition, in order to track capacity usage. The addition of FOG will impact the hydraulic and organic loading capacity of the digestion process. FOG is highly degradable approximately 85 percent according to Kabouris et al. (2008) which will result in fewer additional solids being generated from the system, relative to an equivalent load of wastewater sludge. However, FOG is about 85 to 90 percent water by weight, sometimes more and sometimes less, and thus will impact the overall hydraulic load to the system. Table 13 provides a summary of the impact of FOG addition on system HRT based on the design load condition. If Medford can achieve maximum loading of FOG to its digesters the consumption of capacity will be at a greater rate. Once capacity is reached, in order to maintain the FOG program and stable solids digestion, additional digester capacity will need to be added. Based on the assumptions and calculations, capacity in the digesters would be reached between 2023 and It should be noted that the skill of the pump truck operator can impact the concentration of solids resulting in an increase or decrease in the hydraulic load. Table 13. Hydraulic Impacts of FOG Addition to Medford Digesters Parameters Units Hydraulic load of FOG at design acceptance rate FOG concentration lb-vs/lb-ts FOG concentration lb-ts/lb-fog Average annual 3,259 4,000 4,750 gpd Maximum month 3,259 4,000 4,750 gpd Peak 14-day load 3,259 4,000 4,750 gpd FOG amended HRT at maximum load Average annual day Maximum month day Peak 14-day load day Along with hydraulic impacts, the process will be influenced by organic loading as well. To assess the influence of organic loading it is assumed the FOG load will not exceed the 30 percent of the average annual load. The maximum loading condition to the digester will therefore occur at the peak 14-day sludge flow and load, which most closely represents the minimum HRT desired for the process, and average annual FOG flow and load with two digesters in service. Table 14 provides a summary of the results. 20

21 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Table 14. Impact of FOG Load Addition on Digester Organic Loading Rate Parameters Units FOG-amended organic loading rate (OLR) FOG volatile solids load 2,582 3,169 3,763 lb-fog-vs/day Peak 14-day sludge volatile solids (VS) load 45,000 52,000 61,000 lb-vs/day FOG volatile solids reduction (VSr) lb-vsd/lb-vs Sludge VSr lb-vsd/lb-vs Equivalent FOG load as sludge 3,275 4,019 4,773 lb-vs/day Total volatile solids load 48,275 56,019 65,773 lb-vs/day Organic Loading Rate (OLR) lb-vs/1,000-ft 3 - d The data in Table 14 report the OLR for FOG-amended digesters at the projected peak 14-day sludge flows and loads, with FOG addition to the digester equivalent to the estimated average annual flow and load of FOG. It should be noted that the FOG-associated OLR was converted to a sludge-equivalent load, because most process limitations are reported for digesters on a sewage-sludge-only basis. Given the high volatile solids reduction (VSr) and degradability of FOG it is expected not to behave the same as adding an equivalent mass of sludge. Based on this assumption the OLR data show a lower capacity consumption rate than that observed for hydraulic loading, with capacity being reached beyond Based on this analysis the RWRF has sufficient capacity to accept the maximum FOG load until approximately Beyond 2020 the digestion process will exceed the limits set forth in the Facilities Plan. For Medford to continue long-term FOG acceptance and solids digestion under the Facilities Plan limits, an additional digester would need to be constructed around Biogas Generation The assessment of biogas generation from digesters at Medford was conducted under average annual conditions to estimate the total biogas generated daily. Several process parameters must be estimated or assumed in order to assess the total potential biogas production from a FOG co-digestion program at the RWRF. The following subsections present a discussion of the necessary process parameters, assumptions, and alternative approaches to gas production and a recommended value for biogas production. Evaluation of Biogas Yield from Medford RWRF Digesters Mesophilic anaerobic digesters typically generate 12 to 18 ft 3 -biogas/lb-vs destroyed. Evaluating the observed yield for a facility can provide some insight to the viability of data for assessment of design parameters. The average yield of biogas from the RWRF digesters is 8.8 ± 4.9 and 9.81 ± 6.67 ft 3 -biogas/lb-vs destroyed, based on plant data from and using the mass balance and Van Kleeck approaches to volatile solids destruction, respectively. These average observed yields are considerably below the typical biogas yields for mesophilic digesters. The data suggest that one of two scenarios is occurring at the RWRF: Either there is an overestimation of volatile solids destruction or an under-measurement of biogas production. It is possible that the underestimation of yield is due to both factors rather than a single factor. Gas meters historically have been unreliable in the accurate measurement of biogas, especially if maintenance and calibration of the unit are not up to date. It is recommended that calibration records be checked to eliminate this as a possibility. 21

22 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Further, RWRF staff have reported that the pressure relief valves (PRVs) on the digesters open on a regular basis to release biogas. This condition should not be considered normal as the PRVs are intended for emergency release of biogas only. Consistent opening could be a result of the gas lines not being able to convey the gas to downstream units due to either blockage or under-sizing. These releases could be exacerbated by slug feeding the digesters creating large diurnal gas peaks, which cannot be conveyed away from the digesters. The overestimation of volatile solids destruction can occur through a variety of means including sampling procedures and/or inadequate mixing in the digester. If mixing is inadequate, heavier materials, which include grit and organics, settle out of the digester column and into the cone. This loss of solids including organics can lead to the underestimation of the volatile solids destruction, especially if the mass balance method is used. Typically the deposition of organics with grit leads to an overestimation of VSr with the mass balance method while the Van Kleeck method results in an underestimation. Figure 6 shows the relative impact of biogas yield and volatile solids destruction on the predicted biogas production from a mesophilic anaerobic digester and how the RWRF data compares. Based on the fact that VSr calculations provide minimal opportunities for calculation errors, the controlling factor is likely biogas production or measurement. Biogas Production (ft 3 -biogas/day) Volatile Solids Destruction Observed Gas Production Calculated Gas Production Biogas Yield (ft3biogas/lb-vsd) Figure 6. Influence of VSr and biogas yield on biogas production relative to report values for Medford (Note: green shade represents range of typical biogas yields and yellow represents Medford reported yields; includes all data provided, except Nov through Feb when no data were collected.) 22

23 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Other less likely scenarios would be the presence of a marginally inhibitory compound in the sludge, which may result in a reduction in methanogenic activity. The reduced methanogenic activity could lead to elevated volatile acid content. Volatile acids are lost during the volatile solids testing, thus resulting in lower gas but high volatile solids destruction. The volatile acid data does not suggest any significant concentrations of volatile acids, which would be indicative of this condition. Given the uncertainty in the biogas yield data an assumed value will be used for this analysis as significant underestimation of the gas production data could result in wastage of biogas rather than conversion to electrical power. Therefore, biogas production will be based on a biogas yield of 13 ft 3 -biogas/lb-vs destroyed and FOG, which can exhibit a high biogas yield, will be evaluated at 17 ft 3 -biogas/lb-vsd, a conservative value. For the purposes of this study, synergistic solids destruction enhancement will be ignored. If the load approaches the limits for FOG loading then additional gas may be produced by this effect. The uncertainty in the biogas data has little influence on FOG acceptance but could impact the engine sizing for the cogeneration facility. It is recommended that the discrepancy between observed values and theoretical values be remedied prior to moving into design. Overestimation of biogas production can be as problematic as underestimation. Further exacerbating this concern is that the economic viability of the FOG program depends upon having sufficient cogeneration capacity to generate power from the biogas produced from FOG digestion, resulting in a revenue stream. Estimate of Biogas Production for Medford RWRF Biogas yield values used in this analysis are described in the previous section. The biogas production will be based on average annual conditions for sludge production at the RWRF and the facility receiving the full FOG load. While this will lead to an overestimation of the biogas production in the initial stages, if the program grows to its full potential, there will be sufficient capacity to utilize the gas generated. Table 15 provides a summary of the projected biogas production for the RWRF. Table 15. Estimated Biogas Production from RWRF with and without FOG Addition Parameters Units Wastewater sludge biogas production Average annual TS load 41,000 49,000 58,000 lb-ts/day Average annual VS load 35,000 42,000 50,000 lb-vs/day Average annual VSr lb-vsd/lb-vs Volatile solids destroyed 23,457 28,148 33,510 lb-vsd/day Biogas yield ft 3 -biogas/lb-vsd Calculated biogas production 304, , ,630 ft 3 -biogas/day FOG associated biogas Average annual FOG VS load 2,582 3,169 3,763 lb-vs/day Average annual VSr lb-vsd/lb-vs Volatile solids destroyed lb-vsd/day Biogas yield ft 3 -biogas/lb-vsd Calculated biogas production 37,311 45,795 54,381 ft 3 -biogas/day Total biogas production Biogas calculated 342, , ,011 ft 3 -biogas/day 23

24 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Based on the data in Table15, the addition of FOG to the digesters will increase biogas production by approximately 9 percent, while increasing flow to the digesters by only 2.2 percent. The discrepancy between volumetric usage and gas production indicates that the addition of FOG is an effective use of digester capacity. FOG Receiving Facility A receiving facility designed to receive FOG is typically capable of receiving any other hauled liquid waste, and thus is flexible and robust. The minimum elements required in a FOG receiving station are a rock trap, screening, pumping (typically chopper, positive displacement, or progressing cavity) and process heating. Brown grease, unlike yellow grease, is often contaminated with foreign materials such as rocks and debris. The material shown in Figure 7 depicts materials common to FOG, following many passes through a chopper pump. The flexibility of the plastics make them difficult to break apart and thus to maintain the quality of the biosolids product. Figure 7. Contaminants in brown grease from a pilot test using chopper pumps as the mixing pump The other major element of FOG receiving is process heating of the receiving tank and hot water wash down. FOG at ambient temperatures hardens and coats material, building layers until tanks are filled, pipes are plugged, or screens are blinded. Process heat can be provided by boilers, combined heat and power systems, or heat extractors. It is recommended that any FOG system at Medford be equipped with process heating equipment, including hot water for spray cleaning. A detailed design for a FOG receiving station would need to consider and include adequate safety precautions and equipment for handling hot liquids. Figure 8 provides a basic process flow schematic of a co-digestion substrate receiving facility that has all of the basic elements of a FOG receiving facility. Additional detail would be provided as part of a detailed design or predesign effort. The receiving station is designed to provide both redundancy and decouple FOG receiving from process loading, by providing two aboveground tanks. The equal volume tanks would be plumbed for normal operation with the screened product being loaded to either tank, and the capacity for maintenance or emergency operation when a single tank is out of service. The intent of the two-tank facility is to prevent or reduce the chance of process overloading that could come from a large number of trucks arriving at the facility over a short period of time and not having sufficient storage capacity. Under such a situation the plant would either turn away trucks, which could be detrimental given the limited number of haulers in the region, or would rapidly increase the loading of the digesters, which could create an upset or foaming condition. 24

25 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Figure 8. Basic flow schematic of FOG receiving station with separate receiving and digester loading capabilities The process tanks would both have heating capacity, to ensure that the tanks remain heated and the FOG does not congeal during storage. Mixing pumps are assumed to be a chopper style to further break down particulate material to homogenize and potentially improve the degradability of the materials, by increasing surface area for microbial attack. A rock trap and screen are provided to reduce the introduction of material that could potentially damage or plug equipment or reduce the quality of the biosolids generated by the plant. Based on these criteria and others to be presented, a basic sizing of equipment can be made. It will be assumed that the RWRF facility will have one truck hookup. Assuming that all trucks are 3,000 gallons in size and are able to unload in 20 minutes, including wash down, the maximum receiving rate is three trucks per hour. It is further assumed that the facility will be sized for the year 2020 and that the facilities will be located on a slab outside and the tankage would be located above grade to reduce overall costs. The facility would be located near the existing cogeneration building to minimize pipe conveyance. Using this described facility as a basis of design, the construction cost is estimated at $1.12 million using concrete tanks and $1.07 million using fiberglass reinforced plastic (FRP) tanks. Cost estimate information is included in Appendix A. It should be noted that further cost reductions could be achieved by moving to a single-tank design. This would eliminate a tank and reduce the project footprint and necessary heating and mixing equipment. However, converting to this mode of operation potentially could reduce process flexibility. 25

26 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis FOG Program Net Present Value Analysis A 20-year net present value (NPV) analysis was conducted to evaluate the economic viability of the codigestion of FOG at the Medford RWRF. The preliminary receiving facility described in the previous section was the basis of this analysis. The particular assumptions of this analysis are presented below: Economic parameters and assumptions: Inflation rate for non-power elements is 3 percent per year. Inflation rate for power-based elements is 2.5 percent per year. The discount rate is 5.25 percent per year. Engineering costs are 20 percent of the construction costs. Miscellaneous, administrative cost is 5 percent of construction costs. Project life is 20 years. Operations and maintenance costs: Receiving station power use is based on a constant acceptance of 4,000 gpd of FOG. Tipping fee is $0.10/gal. The retail cost of electricity used at the plant is $0.061 per kilowatt-hour (kw-hr), including all capacity fees. This includes the peak charges associated with electricity costs that at this time cannot be avoided. Power generated by RWRF is sold to the grid at a rate of $0.053/kW-hr, which reflects the rate when peaking charges are excluded. Power generated from FOG biogas will be used to offset plant power use. Biogas cleanup costs for the cogeneration system are $0.08/1,000-ft 3 -biogas treated. The operations, maintenance, and replacement costs for cogeneration engines are $0.016/KW-hr total capacity, assessed at the incremental capacity increase associated with FOG acceptance. All power generated from FOG based biogas will be sold back to the grid rather than offset of plant power needs. This is based on the assumption that the new cogen will meet all normal RWRF power demands and the FOG generated power will not be needed at the plant. The efficiency of the cogeneration engine is 36 percent, based on a Waukesha engine. Mixing upgrade will not consume any more power than the current system. The full daily FOG collection estimate for 2020 would be 4,000 gpd, 7 days per week. FOG production in the region will increase proportionately to the influent VSS load, assuming that it is population-driven. Screening provided by an IPEC TLT screen, cost, and footprint based on a 350-gpm model due to uncertainty in the exact screen to be selected in design. Screening needs are estimated to be 150 gpm for Medford. Heat exchangers are based on DDI (5x5,1.5x5) with the capability to heat to thermophilic temperatures; larger units were used in this analysis to provide excess footprint and cost, due to uncertainty in the units to be selected in design. Odor control is based on a biofilter configuration. It will require the equivalent of one half-time employee to operate and maintain the receiving facility and conduct all needed clerical work. Repair and replacement costs are 5 percent of the capital equipment costs annually. 26

27 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Construction costs and assumptions: The receiving station will be constructed and in full operation in The capital investment in the receiving station will be made as a lump sum in The FOG receiving facility will cost $1.12 million to construct. The mixing on the digesters will be upgraded at a cost of $1.9 million. The acceptance of FOG will incur an additional capital investment in additional engine capacity of 100 kilowatts (kw) at a rate of $2,000 per kw. Using these assumptions and the process data presented in previous sections the NPV of the project was calculated. Working on the model that positive values represent revenue and negative values represent costs the 20-year NPV was estimated to be approximately -$1.57 million, indicating a cost to the City of Medford. Increasing the tipping fees to 0.12 $/gal, the same rate charged by the Merlin WWTP, the NPV improves to -$1,080,000 million dollars. Not until the tipping fee approaches $0.17 per gallon does the receiving facility and mixing upgrade switch to a positive NPV. Figure 9 shows the impact of tipping fees on the NPV and payback period for the proposed facility. Figure 9. Influence of tipping fees on the 20-year NPV and payback period of FOG receiving at the RWRF (Note: positive NPV is a benefit to the City under this analysis and clear data point(s) represent greater than 20-year payback, assumes incremental capital cost of cogeneration is included along with sludge receiving station costs and mixing upgrade costs.) The discounted payback period is greater than 20 years, primarily due to the inclusion of the upgraded mixing system with a capital cost of $1.9 million, per West Yost Associates (TM-Mixing: July 31, 2008). Removal of the mixing upgrade results in a 20-year NPV of $1.17 million at $0.12 per gallon, with a discounted payback of approximately 12 years. However, it should be noted that adequate mixing is required to ensure successful operation of the digestion process with FOG. The payback and overall viability of the program is tied not only to the tipping fee but also to the quantity of material collected by the haulers. Given that FOG is the key revenue source, it is recommended that the City conduct an in-depth analysis of FOG hauling in the region, including direct talks with the haulers prior to initiating design of the facility. 27

28 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Based on the assumptions for costs and revenues and FOG collection conditions, it appears that initiating a FOG program to increase biogas production could be beneficial to the City. Prior to initiating a detailed design for a FOG facility, the City should quantify the amount of FOG truly available through more thorough discussion with local haulers. The success of a FOG receiving program depends on both receiving the FOG and having a beneficial use for the biogas. Accepting FOG and flaring the biogas does provide an environmental benefit relative to lagooning or placing in a landfill as the methane is converted to carbon dioxide, limiting the greenhouse gas (GHG) impacts. However, under the current regulatory structure, reductions in GHG emissions are not monetized as they would be in a cap-and-trade system; thus a beneficial use for the gas must be available to generate the revenue needed to support the program. FOG Impacts to Engine Size As previously summarized, FOG is projected to increase digester gas production by about 37,000 ft 3 /day in It is projected to increase production by as much as 54,000 ft 3 in For engine-generator sizing the midpoint gas production numbers are used to begin the selection process and the available engine-generator sizes are used to further refine the selection. In this case the 2020 gas production increase is estimated at 46,000 ft 3 of gas per day. This equates to approximately 110 kw of increased power production. For sizing a new engine, two potential gas projections were considered for existing conditions. Additional gas generated because of added FOG would be added to each existing condition to project total gas quantities. Based on RWRF data, and using calculations summarized in Table 15, the projected gas quantities are higher than those experienced at the RWRF. These current calculated gas numbers are illustrated in Table 16. Based on Brown and Caldwell s experience, a more conservative projection is presented as an alternative estimate of gas, also illustrated in Table 16. Digester gas energy values of 550 Btu/ft 3 and efficiency values of 34.5 percent for the available digester gas engine-generators are used to convert the available gas to calculated output in Table 16. Table 16. Projected Gas Flows and Engine-Generator Output with and without FOG Gas estimate case Year 2020 gas, ft 3 /day Calculated power output, kw Current calculated gas production 366, Alternative estimated gas production 303, Current calculated gas with FOG 412, Alternative estimated gas with FOG 349, The selection of an engine-generator based on the data in Table 16 depends heavily on the available engine sizes and may be impacted by net metering, a power revenue pricing rule which limits revenue. The revenue is limited because the plant power bill cannot be offset by more power production than the plant uses. Any power beyond the plant s annual consumption would be priced by the utility as an avoided cost. The avoided cost might be half of the power rate paid by the plant or less. Using Waukesha engine-generators as an example, without the FOG increase, especially using the lower alternative estimate above, a Waukesha VFG48GLD engine-generator rated at 650 to 830 kw is recommended. If FOG is added or the higher current estimate is used, a Waukesha APG1000 engine generator is recommended for a number of reasons. This engine is a product of a special Advanced Reciprocating Engine System program that was backed by the U.S. government and had the goal of improving engine-generator efficiency. By using the APG1000 engine about 10 percent more power can be generated with the same amount of fuel. In addition, this selection would produce more power because the smaller engine cannot handle peak gas production as well. 28

29 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis FOG Capital Funding Opportunities Significant grant funding is available for cogeneration projects including the FOG addition portion. The purpose of codigesting FOG is to increase power generation of the existing digesters. Two funding sources are established for this type of project. The State of Oregon s Business Energy Tax Credit (BETC) program funds 33.5 percent for municipal renewable energy projects. The Energy Trust of Oregon (ETO), through its Biopower program, provides funding for above-market costs of energy. Brown and Caldwell and the City plan to meet with ETO representatives on April 28, 2010, to discuss specific incentive amounts for the FOG portion of the project. The cost analysis presented below includes an estimate of ETO incentive. Table 17 lists the total capital project costs, energy incentives, and payback period. The capital costs are divided into two categories FOG and mixing. Mixing improvements would be required if FOG is added to the digestion process. However, mixing has other merits and the City may decide to implement a mixing project regardless of FOG addition. FOG project with mixing Table 17. Funding Potential FOG project with mixing including funding FOG project without mixing FOG project without mixing including funding FOG system capital cost $1,649,311 $1,649,311 $1,649,311 $1,649,311 Mixing capital cost $2,375,000 $2,375,000 $0 $0 BETC tax incentive $0 -$1,348,144 $0 -$552,519 ETO incentive ~ -$500,000 ~ $0 Total $4,024,311 $2,176,167 $1,649,311 $1,096,792 Payback period, years > ETO incentives for renewable energy projects are negotiated specifically for each individual project. The intent of the incentive is to reduce the additional investment required by the City, resulting in an attractive payback period. A payback period of 10 and 15 years is considered typical for this project. Without incentives, a FOG project with mixing does not payback over the life of the project. Receiving BETC incentives results in an approximately 19-year payback. An additional $500,000 is required to return a 15-year payback period. Municipalities often require a payback period more favorable than 15 years. An additional $750,000 in incentives is required to return a 10-year payback period. For this analysis, ETO funding is based on a 15-year payback period. Paying the above-market cost of energy is intended to provide an acceptable return on investment in renewable power. Figure 10 shows the four project scenarios presented in Table 17. An initial capital cost is shown in the year 2011 and the net revenue from electricity is shown over the 20-year life of the project using the same assumptions defined in the present worth analysis. 29

30 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Figure 10. Payback periods for various FOG program scenarios As the project generates power, Renewable Energy Credits (RECs), which represent one mega-watt hour of renewable energy, will accrue. The market value of the RECs is recognized by the ETO, which may choose to negotiate purchase of the RECs as part of their capital funding package. A market is becoming established for RECs and is currently valued at about $7 per REC. FOG addition increases generation by approximately 100kW, and results in approximately $6,000 in RECs per year or approximately $120,000 over the life of the project. RECs are created based on actual power generation, not built capacity. ETO funding is not limited to the value of the RECs (green tags). As the project develops, pursuit of project funding should continue to improve definition of funding. Net Metering Agreement In July 2007, the Oregon Public Utilities Commission (PUC) adopted new rules for net metering for Portland General Electric (PGE) and Pacific Power customers that increased limits from 25 kw to 2000 kw for nonresidential customers. The anticipated size of the gas cogeneration unit is approximately 650 kilowatts and would not exceed the size limit set by the PUC. Net metering is primarily intended to partially offset a customer s requirement for electricity. If at the end of a billing month the customer has delivered net excess generation to the utility, then the excess amount is carried forward to the customer s next bill as a kilowatt-hour credit. Any excess amount remaining at the end of a 12-month period is credited to Oregon s low-income assistance program at the utility s avoided cost rate. Net metering applications for capacity of 2,000 kw or less are subject to either a Level 2 or Level 3 review by Pacific Power. Level 2 applications are deemed by Pacific Power to have only a minor impact on its system and therefore require less scrutiny than Level 3 applications that may require detailed studies to be performed by Pacific Power. Level 2 application fees are $50 base plus $1.00 per kw of net metering facility s capacity plus costs of minor modifications or additional review per Oregon Administrative Rule (OAR)

31 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis Level 3 application fees are $100 base plus $2.00 per kw of the net metering facility s capacity and costs of studies or additional facilities installed by Pacific Power to accommodate the net metering per OAR The proposed cogeneration installation at the Medford plant was discussed with Mr. Travis Tanner of Pacific Power. Mr. Tanner indicated that a Level 2 application would likely suffice. Documentation that would be required to be submitted before approval for interconnection is described in the application and includes a site plan and cut sheets for the cogeneration system specifying the size and type of generator, protective relaying, and utility disconnect switch. In accordance with the terms of a net metering agreement with Pacific Power, this equipment would be customer-furnished and -installed. At this time, details and costs of the proposed cogeneration equipment have not been determined, but it is likely that the specified package will include most of the gear necessary to meet the interconnection requirements of Pacific Power. The net meter capable of recording energy flow in both directions would be furnished by Pacific Power. Peak Use Elimination Alternatives Power generation saves power costs for the plant but it does not usually reduce the size of the transmission system that the power utility must provide for the plant. Utilities recover the costs associated with the equipment and power lines they must provide and maintain by assessing a demand charge. This demand charge is based on the highest 15-minute demand recorded in each month. The demand charge for a month can be reduced by preventing peaks in power use. With an engine-generator a plant is likely to establish its monthly demand peak when the engine-generator is turned off for any reason. The charge that results from shutdown of the engine-generator can be considered a demand penalty. This can be partially avoided by turning off other electrical loads in the plant. For instance, if an oil change takes 2 hours, the plant may be able to turn off a blower and some pumping load during the oil change. Conversely, in months when the engine will be down for an extended period of time, there is no need to take drastic measures to limit demand because nothing can be turned off for as long as the time the enginegenerator will be down. On longer outages during certain times of the year, the plant staff may be able to take some steps to partially reduce demand and save utility costs. Planned long outages of the enginegenerator should be scheduled for times when demand is historically low or when some equipment can be shut down. Many utilities have time-of-day metering, in which demand and energy costs are higher during certain times during the day. Pacific Power reports that it does not have variable rates in the Medford area at different times of the day. This means that no adjustments in time-of-day generation can be made to maximize revenue or avoid costs. Conclusions and Recommendations Initiating a FOG program to increase biogas production could be beneficial to the City. The payback period is longer than expected because of the inclusion of a mixing upgrade project necessary for accepting FOG. However, the FOG receiving station could be designed with less redundancy than was assumed for this study to reduce capital costs and the payback period. If the FOG, mixing, and cogen projects are considered as a single energy project, the amount of incentive funding available could increase significantly. The amount of funding potentially available will be further defined through future meetings with ETO staff. The following critical decisions are necessary for execution of the cogen design project: How to package the final project cogen only or cogen with FOG and mixing. The amount of funding available will vary depending on the final project selected. How to address gas projections that exceed actual operating conditions. This could impact the final engine size selected for the cogeneration design project. 31

32 Technical Memorandum Fats, Oil, and Grease, Net Metering and Electrical Peaking Analysis If the City decides to proceed with further evaluations of a FOG receiving station, there are community teaming partners that should be explored. These include the Jackson County Soil and Water Conversation District, Rouge Valley Sanitary Sewer and Rouge Disposal. References Kabouris, J.C., U.Tezel, S.G. Pavlostathis, M. Engelmann, J. Dulaney, R.A. Gillette, A.C. Todd, (2008). The Mesophilic and Thermophilic Anaerobic Digestion of Municipal Sludge and FOG. Proceedings of the 81st Annual Water Environment Federation Technical Exposition and Conference, Chicago, Ill., October Suto, P., D.M.D. Gray, E. Larsen and J. Hake, Innovated Anaerobic Digestion Investigation of Fats, Oils, and Grease. Proceedings of the Water Environment Federation Residuals and Biosolids Management Conference Cincinnati, Ohio, March Wiltsee, G. Appel Consultants, Inc., Valencia, Calif., Urban Waste Grease Resource Assessment for the National Renewable Energy Laboratory, November 1998, NREL/SR

33 Detailed Cost Information APPENDIX A

34

35 SUMMARY ESTIMATE REPORT WITH MARK-UPS ALLOCATED FOG RECEIVING FACILITY MEDFORD WWTP Project Number: BC Project Manager: D. LAFFITTE BC Office: PORTLAND Estimate Issue Number: 01 Estimate Original Issue Date: JANUARY 26, 2010 Estimate Revision Number: 01 Estimate Revision Date: February 01, 2010 Lead Estimator: J. MATTHEWS Estimate QA/QC Reviewer: B. MATTHEWS/C. MULLER Estimate QA/QC Date: JANUARY 27, 2010 PROCESS LOCATION/AREA INDEX DEMOLITION CIVIL/SITE WORK/YARD PIPING STRUCTURAL EQUIPMENT MECHANICAL ELECTRICAL AND INSTRUMENTATION 2/1/2010-2:41PM

36 Description FOG RECEIVING FACILITY Total w/ Markups Allocated --- Base Estimate --- 1,119, DEMOLITION Site Preparation 6, DEMOLITION Total 6, CIVIL/SITE WORK/YARD PIPING Site Preparation 3, Earthwork 18, Concrete Forms & Accessories 23, Concrete Reinforcement 14, Cast-In-Place Concrete 10, Building Services Piping Process Piping 33, CIVIL/SITE WORK/YARD PIPING Total 104, STRUCTURAL Site Preparation 7, Earthwork 10, Concrete Forms & Accessories 38, Concrete Reinforcement 77, Cast-In-Place Concrete 53, Basic Metal Materials & Methods 16, Structural Metal Framing 3, Metal Fabrications 10, Paints & Coatings STRUCTURAL Total 216, EQUIPMENT Metal Fabrications 56, Equipment 460, EQUIPMENT Total 517, MECHANICAL Metal Fabrications 6, Basic Materials & Methods 23, Building Services Piping 46, Process Piping 73, Heating/Ventilating/Air Conditioning Equipment 5, MECHANICAL Total 156, ELECTRICAL AND INSTRUMENTATION 2/1/2010-2:41PM Page 1 of 2

37 Description FOG RECEIVING FACILITY Total w/ Markups Allocated Electrical and Instrumentation 118, ELECTRICAL AND INSTRUMENTATION Total 118,381 Grand Total 1,119,499 2/1/2010-2:41PM Page 2 of 2

38 DETAILED ESTIMATE REPORT FOG RECEIVING FACILITY MEDFORD WWTP Project Number: BC Project Manager: D. LAFFITTE BC Office: PORTLAND Estimate Issue Number: 01 Estimate Original Issue Date: JANUARY 26, 2010 Estimate Revision Number: 01 Estimate Revision Date: February 01, 2010 Lead Estimator: J. MATTHEWS Estimate QA/QC Reviewer: B. MATTHEWS/C. MULLER Estimate QA/QC Date: JANUARY 27, 2010 PROCESS LOCATION/AREA INDEX DEMOLITION CIVIL/SITE WORK/YARD PIPING STRUCTURAL EQUIPMENT MECHANICAL ELECTRICAL AND INSTRUMENTATION 2/1/2010-2:42PM

39 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ --- Base Estimate DEMOLITION 4, Site Preparation Selective Demolition, Saw Cutting 9000 Selective demolition, Curb and pavement. rework and repair pavement, allowance 1.0 Job 4, , ,500 Site Preparation Total 4,500 2/1/2010-2:42PM Page 1 of 22

40 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ CIVIL/SITE WORK/YARD PIPING 70, Site Preparation Core Drilling 0700 Concrete core drilling, core, reinforced concrete slab, 6" diameter, up to 6" thick slab, 2.0 EA includes bit, layout and set up Selective Demolition, Dump Charges 9999 Dump Charge, typical urban city, fees only, bldg constr mat'ls 77.9 ton ,571 Site Preparation Total 2, Earthwork Backfill, Structural 4420 Backfill, structural, common earth, 200 H.P. dozer, 300' haul L.C.Y Compaction, General 7000 Compaction, around structures and trenches, 2 passes, 18" wide, 6" lifts, walk behind, 13.6 E.C.Y vibrating plate 7000 Compaction, around structures and trenches, 2 passes, 18" wide, 6" lifts, walk behind, 31.3 E.C.Y vibrating plate 7000 Compaction, around structures and trenches, 2 passes, 18" wide, 6" lifts, walk behind, E.C.Y vibrating plate 7040 Compaction, around structures and trenches, 4 passes, 18" wide, 6" lifts, walk behind, E.C.Y vibrating plate Excavating, Bulk Bank Measure 1550 Excavating, bulk bank measure, 1-1/2 C.Y. capacity = 80 C.Y./hour, wheel mounted, B.C.Y excluding truck loading Hauling 2/1/2010-2:42PM Page 2 of 22

41 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0009 Loading Trucks, F.E. Loader, 3 C.Y cuyd Cycle hauling(wait, load,travel, unload or dump & return) time per cycle, excavated or L.C.Y ,105 borrow, loose cubic yards, 15 min load/wait/unload, 12 CY truck, cycle 20 miles, 35 MPH, no loading equipment 4498 Cycle hauling(wait, load,travel, unload or dump & return) time per cycle, excavated or 77.9 L.C.Y borrow, loose cubic yards, 25 min load/wait/unload, 20 CY truck, cycle 20 miles, 45 MPH, no loading equipment Excavating, Trench 0300 Excavating, trench or continuous footing, common earth, 1/2 C.Y. excavator, truck B.C.Y ,834 mounted, 4' to 6' deep, excludes sheeting or dewatering Utility Bedding 0100 Fill by borrow and utility bedding, for pipe and conduit, crushed stone, 3/4" to 1/2", excludes 36.3 L.C.Y ,951 compaction Concrete Forms & Accessories Forms In Place, Walls Earthwork Total 12, C.I.P. concrete forms, wall, job built, plywood, 8 to 16' high, 4 use, includes erecting, 1,144.0 sfca ,212 bracing, stripping and cleaning 2550 C.I.P. concrete forms, wall, job built, plywood, 8 to 16' high, 4 use, includes erecting, sfca ,157 bracing, stripping and cleaning 2550 C.I.P. concrete forms, wall, job built, plywood, 8 to 16' high, 4 use, includes erecting, sfca ,062 bracing, stripping and cleaning Waterstop 0600 Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 71.5 LF Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 24.5 LF Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 16.0 LF /1/2010-2:42PM Page 3 of 22

42 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ Concrete Reinforcement Reinforcing In Place Concrete Forms & Accessories Total 15, Reinforcing steel, in place, walls, #3 to #7, A615, grade 60, incl labor for accessories, excl 5,718.4 lb ,559 material for accessories 0702 Reinforcing steel, in place, walls, #3 to #7, A615, grade 60, incl labor for accessories, excl 1,971.8 lb ,572 material for accessories 0702 Reinforcing steel, in place, walls, #3 to #7, A615, grade 60, incl labor for accessories, excl 1,287.9 lb ,027 material for accessories 2000 Reinforcing steel, unload and sort, add to base 3.2 ton Reinforcing steel, unload and sort, add to base 1.1 ton Reinforcing steel, unload and sort, add to base 0.7 ton Reinforcing steel, crane cost for handling, average, add 3.2 ton Reinforcing steel, crane cost for handling, average, add 1.1 ton Reinforcing steel, crane cost for handling, average, add 0.7 ton Reinforcing steel, in place, dowels, deformed, A615, grade 60, longer and heavier, add lb , Reinforcing steel, in place, dowels, deformed, A615, grade 60, longer and heavier, add lb Reinforcing steel, in place, dowels, deformed, A615, grade 60, longer and heavier, add lb Concrete Reinforcement Total 9, Cast-In-Place Concrete 2/1/2010-2:42PM Page 4 of 22

43 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ Concrete, Ready Mix Normal Weight 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 21.2 CY ,246 Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 7.3 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 4.7 CY Portland cement and water, delivered, excludes all additives and treatments Placing Concrete 5350 Structural concrete, placing, walls, pumped, 15" thick, includes vibrating, excludes material 21.2 CY Structural concrete, placing, walls, pumped, 15" thick, includes vibrating, excludes material 7.3 CY Structural concrete, placing, walls, pumped, 15" thick, includes vibrating, excludes material 4.7 CY Finishing Walls 0150 Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids SF , Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids SF Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids SF Cast-In-Place Concrete Total 7, Building Services Piping Sleeves And Escutcheons 0200 Sleeve, pipe, steel with water stop, 12" long, 6" diam. for 4" carrier pipe, includes link seal 2.0 EA Process Piping Building Services Piping Total 352 2/1/2010-2:42PM Page 5 of 22

44 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ Pipe, Glass Lined Ductile Iron 0020 Piping, DI, glass lined, CL 50, 4'' dia lnft , Piping, DI, glass lined, CL 50, 4'' dia 80.0 lnft , Fittings, Glass Lined Ductile Iron 0070 Fitting, DI, glass lined, 90 deg ell,4'' dia 7.0 each , Fitting, DI, glass lined, tee, 4'' dia 1.0 each Process Piping Total 22,637 2/1/2010-2:42PM Page 6 of 22

45 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ STRUCTURAL 145, Site Preparation Selective Demolition, Dump Charges 9999 Dump Charge, typical urban city, fees only, bldg constr mat'ls ton ,423 Site Preparation Total 5, Earthwork Backfill, Structural 4420 Backfill, structural, common earth, 200 H.P. dozer, 300' haul 18.1 L.C.Y Compaction, General 7500 Compaction, 2 passes, 24" wide, 6" lifts, walk behind, vibrating roller 16.3 E.C.Y Compaction, 3 passes, 24" wide, 6" lifts, walk behind, vibrating roller 64.9 E.C.Y Compaction, 4 passes, 24" wide, 6" lifts, walk behind, vibrating roller 64.9 E.C.Y Hauling 0009 Loading Trucks, F.E. Loader, 3 C.Y cuyd Cycle hauling(wait, load,travel, unload or dump & return) time per cycle, excavated or L.C.Y borrow, loose cubic yards, 25 min load/wait/unload, 20 CY truck, cycle 20 miles, 45 MPH, no loading equipment Excavating, Trench 0060 Excavating, trench or continuous footing, common earth, 1/2 C.Y. excavator, 1' to 4' deep, B.C.Y excludes sheeting or dewatering 0060 Excavating, trench or continuous footing, common earth, 1/2 C.Y. excavator, 1' to 4' deep, 4.0 B.C.Y excludes sheeting or dewatering Utility Bedding 0100 Fill by borrow and utility bedding, for pipe and conduit, crushed stone, 3/4" to 1/2", excludes 75.4 L.C.Y ,055 compaction Concrete Forms & Accessories Earthwork Total 6,751 2/1/2010-2:42PM Page 7 of 22

46 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ Forms In Place, Equipment Foundations 0050 C.I.P. concrete forms, equipment foundations, 2 use, includes erecting, bracing, stripping 26.0 sfca and cleaning 0050 C.I.P. concrete forms, equipment foundations, 2 use, includes erecting, bracing, stripping 44.0 sfca and cleaning 0050 C.I.P. concrete forms, equipment foundations, 2 use, includes erecting, bracing, stripping 76.0 sfca ,296 and cleaning 0050 C.I.P. concrete forms, equipment foundations, 2 use, includes erecting, bracing, stripping 36.0 sfca and cleaning Forms In Place, Slab On Grade 3050 C.I.P. concrete forms, slab on grade, edge, wood, 7" to 12" high, 4 use, includes erecting, sfca ,610 bracing, stripping and cleaning 3550 C.I.P. concrete forms, slab on grade, depressed, edge, wood, 12" to 24" high, 4 use, 16.0 LF includes erecting, bracing, stripping and cleaning 3550 C.I.P. concrete forms, slab on grade, depressed, edge, wood, 12" to 24" high, 4 use, LF ,418 includes erecting, bracing, stripping and cleaning Forms In Place, Walls 2550 C.I.P. concrete forms, wall, job built, plywood, 8 to 16' high, 4 use, includes erecting, sfca ,933 bracing, stripping and cleaning 2550 C.I.P. concrete forms, wall, job built, plywood, 8 to 16' high, 4 use, includes erecting, 1,935.2 sfca ,584 bracing, stripping and cleaning Waterstop 0600 Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 24.0 LF Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 24.0 LF Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 93.9 LF Waterstop, PVC, ribbed, with center bulb, 3/8" thick x 9" wide 69.1 LF Concrete Reinforcement Reinforcing In Place Concrete Forms & Accessories Total 25, Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for 16,488.3 lb ,461 accessories, excl material for accessories 2/1/2010-2:42PM Page 8 of 22

47 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for 2,863.0 lb ,685 accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0602 Reinforcing steel, in place, slab on grade, #3 to #7, A615, grade 60, incl labor for lb accessories, excl material for accessories 0702 Reinforcing steel, in place, walls, #3 to #7, A615, grade 60, incl labor for accessories, excl 1,284.8 lb ,024 material for accessories 0702 Reinforcing steel, in place, walls, #3 to #7, A615, grade 60, incl labor for accessories, excl 9,325.4 lb ,434 material for accessories 2000 Reinforcing steel, unload and sort, add to base 8.5 ton Reinforcing steel, unload and sort, add to base 0.3 ton Reinforcing steel, unload and sort, add to base 0.9 ton Reinforcing steel, unload and sort, add to base 3.2 ton Reinforcing steel, unload and sort, add to base 4.7 ton Reinforcing steel, unload and sort, add to base 0.1 ton Reinforcing steel, unload and sort, add to base 0.1 ton Reinforcing steel, unload and sort, add to base 0.4 ton Reinforcing steel, unload and sort, add to base 0.1 ton Reinforcing steel, crane cost for handling, average, add 8.5 ton /1/2010-2:42PM Page 9 of 22

48 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 2210 Reinforcing steel, crane cost for handling, average, add 0.3 ton Reinforcing steel, crane cost for handling, average, add 0.9 ton Reinforcing steel, crane cost for handling, average, add 3.2 ton Reinforcing steel, crane cost for handling, average, add 4.7 ton Reinforcing steel, crane cost for handling, average, add 0.1 ton Reinforcing steel, crane cost for handling, average, add 0.1 ton Reinforcing steel, crane cost for handling, average, add 0.4 ton Reinforcing steel, crane cost for handling, average, add 0.1 ton Reinforcing steel, in place, dowels, deformed, 2' long, #5, A615, grade EA Reinforcing steel, in place, dowels, deformed, 2' long, #5, A615, grade EA Reinforcing steel, in place, dowels, deformed, 2' long, #5, A615, grade EA Reinforcing steel, in place, dowels, deformed, 2' long, #5, A615, grade EA Reinforcing steel, in place, dowels, deformed, 2' long, #6, A615, grade EA , Reinforcing steel, in place, dowels, deformed, 2' long, #6, A615, grade 60 3,451.2 EA , Reinforcing steel, in place, dowels, deformed, A615, grade 60, longer and heavier, add lb , Cast-In-Place Concrete Concrete, Ready Mix Normal Weight Concrete Reinforcement Total 51, Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, CY ,754 Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 2.0 CY Portland cement and water, delivered, excludes all additives and treatments 2/1/2010-2:42PM Page 10 of 22

49 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 0.4 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 3.0 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 15.1 CY ,598 Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 35.8 CY ,799 Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 1.4 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 1.8 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 5.2 CY Portland cement and water, delivered, excludes all additives and treatments 0300 Structural concrete, ready mix, normal weight, 4000 PSI, includes local aggregate, sand, 1.3 CY Portland cement and water, delivered, excludes all additives and treatments Placing Concrete 1500 Structural concrete, placing, elevated slab, pumped, 6" to 10" thick, includes vibrating, 15.1 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, CY ,956 excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 2.0 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 0.4 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 1.4 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 1.8 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 5.2 CY excludes material 4650 Structural concrete, placing, slab on grade, pumped, over 6" thick, includes vibrating, 1.3 CY excludes material 5350 Structural concrete, placing, walls, pumped, 15" thick, includes vibrating, excludes material 3.0 CY Structural concrete, placing, walls, pumped, 15" thick, includes vibrating, excludes material 35.8 CY , Finishing Floors 2/1/2010-2:42PM Page 11 of 22

50 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0150 Concrete finishing, floors, manual screed, bull float, manual float, broom finish 3,624.0 SF , Concrete finishing, floors, manual screed, bull float, manual float, broom finish 18.0 SF Concrete finishing, floors, manual screed, bull float, manual float, broom finish SF Finishing Walls 0150 Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids SF Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids 1,935.2 SF , Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids 26.0 SF Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids 44.0 SF Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids 76.0 SF Concrete finishing, walls, carborundum rub, wet, includes breaking ties and patching voids 36.0 SF Concrete finishing, walls, sandblast, heavy penetration 38.3 SF Concrete finishing, walls, sandblast, heavy penetration 48.0 SF Concrete finishing, walls, sandblast, heavy penetration SF Concrete finishing, walls, sandblast, heavy penetration 36.0 SF Basic Metal Materials & Methods Drilling Cast-In-Place Concrete Total 36, Concrete impact drilling, for anchors, up to 4" D, 1/2" dia, in concrete or brick walls and 72.0 EA floors, incl bit & layout, excl anchor 0400 Concrete impact drilling, for anchors, up to 4" D, 5/8" dia, in concrete or brick walls and 25.0 EA floors, incl bit & layout, excl anchor 0400 Concrete impact drilling, for anchors, up to 4" D, 5/8" dia, in concrete or brick walls and 42.0 EA floors, incl bit & layout, excl anchor 2/1/2010-2:42PM Page 12 of 22

51 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0400 Concrete impact drilling, for anchors, up to 4" D, 5/8" dia, in concrete or brick walls and 74.0 EA floors, incl bit & layout, excl anchor 0400 Concrete impact drilling, for anchors, up to 4" D, 5/8" dia, in concrete or brick walls and 34.0 EA floors, incl bit & layout, excl anchor Expansion Anchors 8250 Wedge anchor, carbon steel, 1/2" dia x 2-3/4" L, in concrete, brick or stone, excl layout & 72.0 EA drilling Machinery Anchors 0800 Machinery anchor, heavy duty, 1" dia stud & bolt, incl sleeve, floating base nut, lower stud & 6.0 EA coupling nut, fiber plug, connecting stud, washer & nut 0800 Machinery anchor, heavy duty, 1" dia stud & bolt, incl sleeve, floating base nut, lower stud & 12.0 EA ,881 coupling nut, fiber plug, connecting stud, washer & nut 0800 Machinery anchor, heavy duty, 1" dia stud & bolt, incl sleeve, floating base nut, lower stud & 24.0 EA ,762 coupling nut, fiber plug, connecting stud, washer & nut 0800 Machinery anchor, heavy duty, 1" dia stud & bolt, incl sleeve, floating base nut, lower stud & 8.0 EA ,254 coupling nut, fiber plug, connecting stud, washer & nut Welding Structural 1800 Welding structural steel in field, 3 passes, 0.5 Lb/LF, 3/8" thick, continuous fillet, type LF Basic Metal Materials & Methods Total 10, Structural Metal Framing Lightweight Framing 0476 Angle framing, structural steel, 3"x3"x3/8", field fabricated, incl cutting & welding 18.0 LF Plates 0300 Steel plate, structural, for connections & stiffeners, 3/8" T, shop fabricated, incl shop 18.0 SF primer Structural Steel Members 0102 Structural steel member, 100-ton project, 1 to 2 story building, W6x9, A992 steel, shop 48.0 LF ,133 fabricated, incl shop primer, bolted connections Metal Fabrications Ladder Structural Metal Framing Total 2,193 2/1/2010-2:42PM Page 13 of 22

52 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 0020 Ladder, shop fabricated, steel, 20" W, bolted to concrete, incl cage 14.0 vlft , Ladder, shop fabricated, steel, 20" W, bolted to concrete, incl cage 14.0 vlft , Railing, Pipe 0210 Railing, pipe, aluminum, clear finish, 3 rails, 3'-6" high, 5' O.C., 1-1/2" dia, shop 24.0 LF ,087 fabricated Floor Grating, Aluminum 0132 Floor grating, aluminum, 1-1/2" x 3/16" bearing 1-3/16" O.C., cross 4" 32.0 SF ,428 O.C., up to 300 S.F., field fabricated from panels Grating Frame 0020 Grating frame, aluminum, 1" to 1-1/2" D, field fabricated 32.0 LF Metal Fabrications Total 7, Paints & Coatings B & C coating specification 0090bc Coatings & paints, B & C coating system EP sqft Paints & Coatings Total 35 2/1/2010-2:42PM Page 14 of 22

53 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ EQUIPMENT 338, Metal Fabrications Miscellaneous Fabrication 0100bc Trash rack, 1'x1'x2', carbon steel, compl incl frame 1.0 each bc Odor control, sump covers, alum., removable,with support steel 9.0 sqft , bc Odor control, sump covers, alum., removable,with support steel 9.0 sqft , bc Odor control, tank covers, alum., removable,with support steel 96.0 sqft , bc Odor control, tank covers, alum., removable,with support steel 96.0 sqft ,990 Metal Fabrications Total 37, Equipment Process Equipment 0120 Odor control, bio-filter, complete with fan 1.0 each 1, , , , Mechanical screen, 350 gpm, IPEC TLT 350, complete 1.0 each 2, , , , Heat Exchanger, 500 gpm, complete 2.0 each 1, , , , Pumps, general utility 0220 Pump, chopper, centrifugal,200gpm,10hp,4''d 2.0 each , , , Pumps miscellaneous 0131DSProgressive cavity pump, CI, 2-4 GPM, Seepex, complete 2.0 each , , , Pumps submersible 0010 Wastewater, submersible chopper,150 gpm,guide rails, base elbow 2.0 each , , , Wastewater, submersible chopper,150 gpm,guide rails, base elbow 2.0 each , , , Pumps, circulating 0210 Pumps, crcltg, htd or CHW appl, CI, flange conn, 3'' size, 1 HP 1.0 each , , ,891 Equipment Total 300,677 2/1/2010-2:42PM Page 15 of 22

54 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ MECHANICAL 103, Metal Fabrications Miscellaneous Fabrication 0020bc Pump mounting base plate, complete w/ anchor bolts, 8 sf 2.0 each , , ,715 Metal Fabrications Total 4, Basic Materials & Methods Miscellaneous Mechanical 0040 Kam-lok, quick disconnect, w/cap, 6'', stainless steel 1.0 each Utility stations, complete w/ valve, hose, rack,signage 2.0 each , Hot sludge flush connection on conveyance line, allowance 1.0 each , , Pipe Hangers And Supports 9070 Pipe supports, allowance 1.0 EA 2, , , , Piping System Identification Labels 0124 Piping system identification labels, pipe markers, indicate contents and flow direction, 12.0 EA plastic snap around, 4" pipe 0126 Piping system identification labels, pipe markers, indicate contents and flow direction, 10.0 EA plastic snap around, 6" pipe Piping Insulation 6940 Insulation, pipe covering (price copper tube one size less than I.P.S.), fiberglass with all LF ,163 service jacket, 1" wall, 4" iron pipe size 6960 Insulation, pipe covering (price copper tube one size less than I.P.S.), fiberglass with all LF ,679 service jacket, 1" wall, 6" iron pipe size Building Services Piping Valves, Iron Body Basic Materials & Methods Total 15, Valves, iron body, swing check, threaded, 125 lb., 4" 16.0 EA , , , Valves, Semi-Steel 2/1/2010-2:42PM Page 16 of 22

55 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ 7030 Valves, semi-steel, lubricated plug valve, flanged, 200 lb., 4" 16.0 EA ,244 Building Services Piping Total 31, Process Piping Fittings, Ductile Iron 0150 Piping, fittings, wye or tee, 6'' diameter 1.0 each Piping, fittings, wye or tee, 6'' diameter 1.0 each Flanges, Ductile Iron 0080 Stl ftg, gskt & bolt set, 150#, 6'' pipe 6.0 each Blind flg, CI, black, 125 lb, per flg, 6'' pipe 2.0 each Pipe, Fiberglass Reinforced (FRP) B84Y Odor control, piping allowance 1.0 ea 2, , , , Pipe, Glass Lined Ductile Iron 0020 Piping, DI, glass lined, CL 50, 4'' dia lnft , Piping, DI, glass lined, CL 50, 6'' dia lnft , Fittings, Glass Lined Ductile Iron 0070 Fitting, DI, glass lined, 90 deg ell,4'' dia 6.0 each , Fitting, DI, glass lined, 90 deg ell,6'' dia 6.0 each , Fitting, DI, glass lined, tee, 4'' dia 4.0 each , Fitting, DI, glass lined, tee, 6'' dia 4.0 each , Fitting, DI, glass lined, reducer, 6'' dia 4.0 each , Fitting, DI, glass lined, reducer, 4'' dia 4.0 each ,196 2/1/2010-2:42PM Page 17 of 22

56 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ Pipe, 316 Stainless Steel 0140 Pipe, SS, A778, weld, Sched. 10S, type 316L, 1.5" dia lnft , Pipe, SS, A778, weld, Sched. 10S, type 316L, 6" dia lnft , Flexible Connectors 301 Connectors, flex, dismantling Joint, 4" 16.0 each ,991 Process Piping Total 48, Heating/Ventilating/Air Conditioning Equipment Electric Heating 4050 Electric heating, heat trace system, 400 degree, 115 V, 10 watts per L.F LF ,811 Heating/Ventilating/Air Conditioning Equipment Total 3,811 2/1/2010-2:42PM Page 18 of 22

57 FOG RECEIVING FACILITY Total Labor Materials Subs Equip Other Total Net Item Item Description Qty Unit $/Unit $/Unit $/Unit $/Unit $/Unit $/Unit Cost $ ELECTRICAL AND INSTRUMENTATION 82, Electrical and Instrumentation Electrical and Instrumentation 0001 Electrical and Instrumentation Subcontract 1.0 lsum 82, , ,500 Electrical and Instrumentation Total 82,500 2/1/2010-2:42PM Page 19 of 22

58 2/1/2010-2:42PM Page of 22

59 FOG RECEIVING FACILITY Category Percent Amount --- Base Estimate --- Totals Labor % 176,311 Material % 461,637 Subcontractor % 87,000 Equipment 1.68 % 12,530 Other 1.07 % 7,995 User Net Costs 745,473 Labor Mark-up % 17,631 Material Mark-up 8.00 % 36,931 Subcontractor Mark-up 5.00 % 4,350 Equipment Mark-up 8.00 % 1,002 Material Shipping & Handling 2.00 % 7,493 Contractor General Conditions % 81,288 Subtotal 894,168 Start-up, training, O & M 2.00 % 6,938 Subtotal 901,106 2/1/2010-2:42PM Page 21 of 22

60 FOG RECEIVING FACILITY Category Percent Amount Construction Contingency % 180,221 Subtotal 1,081,328 Bldg Risk, Liability Auto Ins % 21,627 Subtotal 1,102,954 Bonds 1.50 % 16,544 Subtotal 1,119,499 Total Estimate 1,119,499 2/1/2010-2:42PM Page 22 of 22

61 SUMMARY ESTIMATE REPORT WITH MARK-UPS ALLOCATED FOG RECEIVING FACILITY - XLHDPE TANK OPTION MEDFORD WWTP Project Number: BC Project Manager: D. LAFFITTE BC Office: PORTLAND Estimate Issue Number: 01 Estimate Original Issue Date: JANUARY 26, 2010 Estimate Revision Number: 01 Estimate Revision Date: FEBRUARY 1, 2010 Lead Estimator: J. MATTHEWS Estimate QA/QC Reviewer: B. MATTHEWS/C. MULLER Estimate QA/QC Date: JANUARY 27, 2010 PROCESS LOCATION/AREA INDEX DEMOLITION CIVIL/SITE WORK/YARD PIPING STRUCTURAL EQUIPMENT MECHANICAL ELECTRICAL AND INSTRUMENTATION 2/1/2010-2:35PM

62 Description FOG RECEIVING FACILITY - XLHDPE TANK OPTION Total w/ Markups Allocated --- Base Estimate --- 1,072, DEMOLITION Site Preparation 6, DEMOLITION Total 6, CIVIL/SITE WORK/YARD PIPING Site Preparation 3, Earthwork 18, Concrete Forms & Accessories 23, Concrete Reinforcement 14, Cast-In-Place Concrete 10, Building Services Piping Process Piping 33, CIVIL/SITE WORK/YARD PIPING Total 104, STRUCTURAL Site Preparation 7, Earthwork 10, Concrete Forms & Accessories 37, Concrete Reinforcement 65, Cast-In-Place Concrete 38, Basic Metal Materials & Methods 16, Structural Metal Framing 3, Metal Fabrications 10, Paints & Coatings STRUCTURAL Total 188, EQUIPMENT Metal Fabrications 5, Equipment 492, EQUIPMENT Total 497, MECHANICAL Metal Fabrications 6, Basic Materials & Methods 23, Building Services Piping 46, Process Piping 73, Heating/Ventilating/Air Conditioning Equipment 5, MECHANICAL Total 156,114 2/1/2010-2:35PM Page 1 of 2

63 Description FOG RECEIVING FACILITY - XLHDPE TANK OPTION Total w/ Markups Allocated ELECTRICAL AND INSTRUMENTATION Electrical and Instrumentation 118, ELECTRICAL AND INSTRUMENTATION Total 118,381 Grand Total 1,072,414 2/1/2010-2:35PM Page 2 of 2

64 DETAILED ESTIMATE REPORT FOG RECEIVING FACILITY - XLHDPE TANK OPTION MEDFORD WWTP Project Number: BC Project Manager: D. LAFFITTE BC Office: PORTLAND Estimate Issue Number: 01 Estimate Original Issue Date: JANUARY 26, 2010 Estimate Revision Number: 01 Estimate Revision Date: FEBRUARY 1, 2010 Lead Estimator: J. MATTHEWS Estimate QA/QC Reviewer: B. MATTHEWS/C. MULLER Estimate QA/QC Date: JANUARY 27, 2010 PROCESS LOCATION/AREA INDEX DEMOLITION CIVIL/SITE WORK/YARD PIPING STRUCTURAL EQUIPMENT MECHANICAL ELECTRICAL AND INSTRUMENTATION 2/1/2010-2:36PM