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TC Council Packet 03-11-2008 PROPOSAL TO DESIGN AND CONSTRUCT A DEMONSTRATION FACILITY: WASTEWATER HEAT RECOVERY TO SNOW MELT SYSTEM A COOPERATIVE VENTURE AND JOINT APPLICATION BY: TOWN OF AVON COLORADO and EAGLE RIVER WATER AND SANITATION DISTRICT Page 1 of 15 3/4/2008 I. Summary Eagle River in Autumn Two local entities are working cooperatively to conduct urban renewal, replace aging and inefficient infrastructure, and to build a better community in Avon, Colorado. The Town of Avon (Town) is the local government authority who provides services including public works, transit, building permitting, public safety, recreational services engineering, and general government, and engineering services. Eagle River Water and Sanitation District (District) provides potable water and collection, treatment, and disposal of wastewater in Avon. The Town Council and the District Board have mutual goals of conserving energy and providing long-term operational sustainability as the local population grows. This proposal represents a joint application by the Town and the District to design and construct a heat recovery system which will extract waste heat from the wastewater treatment plant (WWTP) and deliver it to sidewalk areas within the urban renewal zone to melt snow and ice in order to improve pedestrian safety. Power for this system would be provided by wind-generated electricity purchased from Holy Cross Energy, resulting in a near-zero carbon footprint. The project will achieve a reduction in the wastewater effluent temperature which is discharged to the Eagle River during fish-sensitive periods. The Town and the District also expect to save tax and rate payers money as a result of this project as compared to other alternatives or the status quo because it results in a more sustainable long-term operation. This exciting project will be the first of its kind – to use plant waste heat for a snow melt system – in the United States. Preliminary engineering analysis was performed by Town engineering staff who determined that the proposed project is technically feasible and appears to be cost effective, primarily because the Avon WWTP and the targeted core pedestrian areas are in close proximity to one another. The District has agreed to locate the mechanical and electrical equipment on the WWTP site and to share in the construction and operations cost of the system. The Town has agreed to limit the surface area for snow melt in the urban renewal area to that which can be served by this heat recovery system, focusing on only the busiest pedestrian areas. Both agencies have made a commitment to share in the construction and operational costs of the project in proportion to the benefits achieved. This document provides a description of the proposed project which can be used to communicate with project stakeholders and the public. This document includes the necessary elements of a grant application, including introductory information, project benefits, technical details, financial considerations, and project management plan and schedule. This project shows how local agencies can work cooperatively for mutual benefit to provide infrastructure which accommodates growth and urban renewal and simultaneously demonstrate strong environmental leadership. Page 2 of 15 3/4/2008 II. Introduction Avon, Colorado, located in the heart of the Rocky Mountains, is a growing community which is strongly dependant on a quality environment and recreation-based economy. The town is located at 7420 feet MSL and has four distinct seasons, including snowy cold winters lasting from mid- November until mid-April. Currently, the population of Avon averages about 7,500 (swelling to about 12,000 during the winter months). This population is projected to grow to a year-round average of about 20,000 by 2020. Avon is undergoing urban renewal and revitalization in the downtown core to eliminate blight and improve economic conditions, provide local jobs and attainable housing, to offer transportation connections to the regional area. Eagle River Kayaker The Eagle River is a sparkling clear river supplied from several of Colorado’s highest peaks; this river runs from Tennessee Pass through Avon and discharges at an average daily rate of about 565 cfs into the Colorado River about 50 miles downstream in Glenwood Springs.1 Avon residents and visitors alike depend on the Eagle River in numerous ways. This river is a designated for Recreational Use with many active recreational uses including abundant trout fishing, white water rafting, and kayaking. This river is both the source of potable water and the recipient of treated wastewater. The Eagle River continues to receive pressure from a growing population. The State of Colorado Department of Public Health and Environment has expressed concerns about the River’s ability to receive warm wastewater discharges in the fall and early winter. The District operates the Avon Wastewater Treatment Plant (WWTP). This plant has an average flow of 2.2 mgd and discharges to the Eagle River in Avon at a point when the average daily river flow rate is about 316 cfs.2 During September and October, minimum river flows at this location have been recorded by U.S.G.S. at about 102 cfs.3 Avon WWTP staff has observed effluent temperatures during these months that are in the range of 14˚C to 16˚C. For this reason, the District is considering extracting and dissipate heat from plant effluent. The District is also looking at means to extract heat from it’s aerobically digested sludge process (ATAD) prior to centrifugation. If this sludge stream can be cooled down about 25˚C, the District would gain substantial efficiencies in biosolids processing, including reduced polymer usage, increased centrifuge throughput and an associated decrease in operation hours, plus a drier final biosolids product cake which results in lower hauling costs. Together these two heat sources represent about 5,800 KW- thermal available for beneficial use. The District has only a limited need to beneficially use waste heat at the Avon WWTP. A small amount of waste heat could be used to snow melt a paved driveway and receiving dock surface. This improvement would allow the plant areas currently set ERWSD Loading Dock and driveway Page 3 of 15 3/4/2008 aside for stockpiling large piles of snow to be made available for other uses, and the District would likely realize lower costs associated with plowing. Other than this use, the District does not have an immediate need to use the majority of the waste heat generated from the wastewater treatment process. The District has offered to make such excess heat available to the Town of Avon, a nearby neighbor. The Avon WWTP is located adjacent to the Town’s urban renewal area, separated from town-owned land by a Union Pacific Railroad right-of-way. Blighted area to be Improved by Project The Town of Avon is undergoing a major urban renewal effort to eliminate blight and stimulate the economy. One important objective of this effort is the creation of vibrant streetscapes and multi-modal transportation connections. Urban renewal is expected to increase the number of jobs and local live-work arrangements associated with recreational tourism. Winter tourism is especially strong, as visitors come to Avon’s affordable off-mountain lodges and restaurants while skiing and snow boarding at nearby areas including Vail and Beaver Creek. In the downtown core areas of Avon, pedestrian traffic is high. Many individuals are wearing ski boots and carrying sports equipment during the winter. Snowy and icy surfaces create slipping and falling hazards, increase the Town’s insurance claims, and work against the Town’s goals of creating a vibrant streetscape in this area. For this reason, a snow melt system for the streets, sidewalks, and paths was incorporated into the urban renewal project over a relatively large area (155,000 sf). The Town considered either natural gas fired boilers or ground loop pumping alternatives that would have consumed approximately 348,000 therms of natural gas or 3,620,000 KW-hrs of electricity, respectfully. The least cost option (natural gas boilers) was estimated to cost approximately $4.45 million to construct and about $650,000 per year to operate and would have emitted more than 2,100 tons of carbon dioxide into the atmosphere. After recently taking bold actions to reduce the Town’s carbon footprint via purchase of 100% of electrical power as wind power in January 2008, the Avon Town Council voted against pursuing the large snow melt streetscape and sought other options to fulfill urban renewal goals in a more sustainable manner.4 Current and Proposed Future look of Streetscape in Avon’s Urban Renewal Area (note snow melt system in use on right) Page 4 of 15 3/4/2008 District and Town staff met informally in January 2008 to discuss progress on urban renewal efforts. Staff identified this sustainability initiative as a win-win for the Town, the District, the Eagle River, and local residents. III. Project Statement and Benefits This project proposes to use waste heat from the wastewater plant as the prime energy source for a snow melt system in core pedestrian and high-risk areas in Avon, Colorado. The waste heat would be transferred using a heat-pump system, powered by renewable wind-generated electricity, to virtually eliminate the carbon footprint of the system. This project offers a demonstration of how common process technology and mechanical components can be applied in a unique way to solve several problems facing communities today. There are many facilities in the U.S. that shed waste heat without obtaining any benefit from it. Heat recovery systems such as the one proposed here have a wide application. This project will demonstrate the degree of energy efficiency available with current heat recovery technology. It would be the first of it’s kind in the United States with respect to the use of waste heat from a wastewater plant for the creation of a snow melt system. The project demonstrates the range of options available to local governments to tackle difficult issues (e.g., climate change, urban renewal, limited resources) if they can be resourceful and work together. At the local level, this project has very direct and exciting benefits, including: • The Town is able to improve the safety and vitality of core pedestrian areas without increasing the Town’s current total carbon footprint. • The Eagle River benefits when the effluent temperature is reduced prior to river discharge, improves river temperatures for fish spawning. • The District will increase the cost-effectiveness of solids treatment processing by reducing expensive polymer consumption and increasing biosolids cake dryness. Assuming a 50% reduction in polymer usage results, the District could realize an annual savings of about $20,000.5 • The District benefits by reducing their plant site area currently lost to snow storage and reducing the risk of back-up of the plant drain and sand-water separator systems. • The Town expects to save approximately $100,000 per year in operations cost, as compared to what was originally planned for the pedestrian snow melt system. As compared to other projects competitively seeking regional or national grant funds for support, this project includes: • Multi-agency cooperation • Environmental leadership • Zero carbon footprint operation • Improves river water temperatures for fish spawning • Reduces risk for liability claims (from trips and falls) • Results in first system of its type in the U.S. This project will result in economic benefits to both agencies. An after-project operational savings of about $20,000 per year has been estimated for the District and about $100,000 per yearfortheTown. Page 5 of 15 3/4/2008 • Assists with urban renewal of a blighted area • Wastewater plant contributes tangible neighborhood benefit IV. Technical Details ATAD process stream piping Figure 1 offers a draft sketch of the proposed heat recovery system process and information diagram (P&ID). Figure 2 shows the project site and physical locations. Three small parallel trains of mechanical equipment consisting of one plant effluent pump, one heat pump compressor, and one glycol pump is anticipated to capture waste heat from the plant and transfer it to a glycol supply piping. Only a portion of the plant’s final effluent (FE), a maximum of 1,040 gpm (1.5 mgd), would be pumped through the heat recovery system and none of this effluent would ever leave the plant property, eliminating concerns about water rights. That portion of the effluent which is cooled through the heat recovery system would be blended back with the remainder of the effluent in the final effluent discharge piping, and would flow on to the river outfall. Jacketed piping or a shell and tube heat exchanger would be also installed around the existing auto-thermophilic aerobic digestion (ATAD) circulation and discharge piping to extract heat. Either the glycol piping would be connected to this heat exchanger or jacketed piping arrangement, or a 2-stage evaporator could be used (as shown in Figure 1). New electrical service, switchgear, transformer, motors, and controls will also be required to be located at the plant. Due to severe winter weather and existing space limitations, this system must be housed indoors in a new building. The glycol supply (GLY-S) and return (GLY-R) piping operates in a closed-loop configuration. This piping would be located within the plant site to deliver heat to the District’s on-site snow melt system and would extend off site into Town-owned right-of-way and connected to the snow melt system in public pedestrian areas. A pair of 8-inch diameter pipes would be installed and located approximately as shown in Figure 2. The piping would be insulated and buried at least 4 feet deep to be below the frost zone and to minimize heat losses. The distance between the plant and the snow melt connection is approximately 1,700 LF; most of this distance is in the grassy area along the south side of Benchmark Road. The pipe alignment includes one crossing under a Union Pacific Railroad. The Town does not expect difficulty in obtaining a utility easement for this crossing. Once fully completed, the heat recovery system would reduce the effluent temperature for the processed effluent flow of 1,040 gpm by approximately 10˚C (e.g., from 15˚C to 5˚C). The ATAD stream would be a flow of about 300 gpm and reduce temperature from about 54ºC to about 20ºC. The closed glycol loop would have a flow of about 1,150 gpm and would operate at a temperature differential of approximately 25˚C between the GLY-S and GLY-R (e.g., from 25˚C to 50˚C). Pa g e 6 o f 1 5 3 / 4 / 2 0 0 8 Fi g u r e 1 . P r o c e s s a n d I n f o r m a t i o n D i a g r a m Page 7 of 15 3/4/2008 The system would be controlled analogous to common similar systems. Moisture and temperature sensors at the pavement surfaces would call for increased pumping rates when snow begins to accumulate. Temperature of the glycol loop in comparison to pre-selected temperature set points would be used to as a trimming signal. The thermostat on the heat pump would be connected to the glycol temperature measurement system. The District would add this system to its existing supervisory control and data acquisition system (SCADA), allowing for display on the operator’s terminal. Back-up power would not be necessary for this system. In the event of a power outage, the system could be manually re-set when grid power is restored to the plant. The system as described would deliver up to about 3000 KW-thermal from the effluent and about 2800 KW-thermal from the ATAD stream to the GLY loop. Note that the ATAD stream is not a constant flow stream; ATAD biosolids are normally processed through to the centrifuges as a batch operation about 8 hours per day, seven days per week. For purposes of snow melting pavement, the agencies are assuming that a dedicated heat recovery of about 3,000 KW-thermal would be available from one plant heat source or the other. An area of approximately 75,000 sf could be consistently snow melted with this amount of heat. At present, the expected uses would include about 10,000 sf located at the District’s plant and about 65,000 sf located in the Town’s pedestrian areas. The total electrical demand connection for the equipment on this system (e.g., all trains housed at the new pump station at Avon WWTP) is estimated to be about 750 KW.6 Operation of the system during the winter will consume approximately 800,000 kw-hrs of wind- generated electricity and no natural gas; consequently, the carbon emissions from operation would be virtually zero. V. Financial Considerations Capital Costs The planning level estimate of probable cost for this system is approximately $2.45 million to plan, design, and construct (January 2008 dollars). This estimate does not include costs for the Town’s street revitalization projects on Lake Street and Main Street or the District’s cost to reconstruct their driveway and loading dock to install snow melt piping. These excluded costs would be born directly by the respective agencies. A breakdown of cost components is shown in Table 1. The Town and the District have agreed to split the design and project administration costs (i.e., “soft costs”) equally, with each agency paying 50% up to a maximum of $90,000. The agencies are applying for grant funds to be used for the construction phase. Assuming that a significant portion of the target grant funding is obtained, the two agencies have agreed to pro-rate the remaining costs (i.e., all non-grant funded costs) in proportion to the benefits achieved. An even project cost split for construction costs has been assumed in Table 1 for discussion purposes. Grant Eligibility The agencies are seeking grant funding up to 80% of the project, with 20% being provided as a local match. The following potential funding partners and grant sources have been identified thus far: This project allows the Town to meet both its sustainability goals and achieve urban renewal with a safer and more vibrant .streetscape. Page 8 of 15 3/4/2008 Table 1. Estimate of Probable Capital Cost Total Project Soft Costs A/E Fees (10%) $ 120,000 CM fees (2%) $ 45,400 Surveys and Tests (0.5%) $ 11,400 Permits and Fees (0%) $ - Subtotal Soft Costs $ 176,800 Construction Cost Pump Building $ 200,000 Glycol Pumps (3 @ 350 gpm) $ 120,000 Wastewater Effluent Pumps (3 @ 350 gpm) $ 90,000 Heat Pumps (3) $ 180,000 Heat Exchanger (1) $ 30,000 GLY Pipe (3400 LF 8" sch80 PVC, double-walled, buried 4' along r.o.w.) $ 408,000 Jackets, Insulation, pipe supports $ 61,200 Electrical (1 MW service, transformer, motors, switchgear) $ 150,000 Instrumentation and Controls $ 50,000 Equipment pads and misc. structural $ 40,000 Site Civil $ 50,000 Miscellaneous $ 20,000 Subtotal $ 1,399,200 Contingency (25%) $ 349,800 Subtotal Construction Cost $ 1,749,000 General Contractor's Overhead and General Conditions (18%) $ 314,820 General Contractor's Profit (11.8%) $ 206,000 Total Constuction Cost $ 2,270,000 Estimated Total Project Cost $ 2,450,000 Proposed Cost Sharing: Soft Costs Grant Request (0%) $ - Town of Avon (50%) $ 88,400 Eagle River Water and Sewer District (50%) $ 88,400 Check Total $ 176,800 Construction costs Grant Request (80%) $ 1,816,000 Town of Avon (10%) $ 227,000 Eagle River Water and Sewer District (10%) $ 227,000 Check Total $ 2,270,000 Page 9 of 15 3/4/2008 • Water Environment Research Federation • State of Colorado – Governor’s Energy Office • Federal Government o Department of Agriculture Renewable Energy Systems and Energy Efficiency Improvements o Department of Agriculture Conservation Innovation Grants o Department of Energy State Energy Program Special Projects • Holy Cross Energy • American Public Works Association • StEPP Foundation (Strategic Environmental Project Pipeline) • Turner Foundation • Trout Unlimited • Vail Resorts Operating and Maintenance Cost The cost estimate to operate the heat recovery system at the Avon WWTP is approximately $350,000 per year (January 2008 dollars). A cost-sharing agreement has been developed between the authorizing agencies as follows: • The Town pays for operation of the heat recovery system throughout the year; the electric meter would be assigned to the Town. This allows the agencies to use wind-generated electricity that the Town purchases from Holy Cross Energy to power the system. • The District contributes funding annually to the Town’s general fund to compensate for electric power to run the system during months when snow melting is not necessary but when the District elects to shed waste heat. (Snow melting is generally necessary only from November 15th through March 31st). • The District provides the land, indoor building space, utilities and control system connections (excluding electricity), and plant inter-ties for mechanical and electrical system components at the Avon Wastewater Treatment Plant. • Maintenance of the system is conducted by District staff and billed to the Town of Avon at cost. VI. Project Management Plan and Schedule This is a two-agency project to be conducted by the Town and the District. Jennifer Strehler, Director of Public Works for the Town, and Chris Maines, Wastewater Operations Manger for the District, will execute this project cooperatively. Jennifer and Chris are working together to develop the final project plans, communicate with internal engineering staff and consultants, report to the District board and local Avon leaders on progress, and manage the project’s overall scope, schedule, budget and quality. _________(consultant name here) is under contract by the _______(Town/District?) to provide engineering predesign and design services for this project. Contact information for the agencies and the engineering consultant is as follows: Page 10 of 15 3/4/2008 Table 2. Contact Information Town of Avon Eagle River Water and Sanitation District Consultant Jennifer Strehler, P.E. Director of Public Works 500 Swift Gulch Road P.O. Box 975 Avon CO 81620 Tel: (970) 748-4100 FAX: (970) 748-1958 jstrehler@avon.org Chris Maines Wastewater Division Manager 846 Forest Road Vail, CO 81657 Tel: (970) 477-5494 FAX: (970) 477-5434 cmaines@erwsd.org Fill in after engineer is retained The construction phases will be competitively bid, with award to the responsive and responsible general contractor who offers the lowest monetary bid. The Town would take the lead on awarding the contracts for construction and managing project financing and payments to contractors, with the District acting in a repayment capacity for shared-cost items and providing on-site inspection of the mechanical and electrical work conducted within Avon WWTP property. A project schedule is attached in Figure 3. The system would be fully designed and then constructed in two phases. The physical layout of the construction phasing is shown in Figure 4. The first phase would involve installation of the building, electrical upgrades and one complete mechanical train (effluent pump, heat pump, glycol pump). Phase I would also include construction of the glycol loop piping between the WWTP and Avon Station. Avon Station is a multi-modal hub which connects car, transit, pedestrian, bicycle, gondola and a future light-rail link. A snow melt system (about 25,000 sf in area) is already in place under brick pavers at Avon Station. Additional pavers will be added down Lettuce Shed Lane by the Town in the near future. Phase II would include expansion of the snow melt piping from Lettuce Shed Lane to the east and west to plaza areas and sidewalks located along the Avon’s new Main Street (planned for construction in 2009). Phase II would also include addition of the remaining two trains of mechanical equipment at the WWTP in the Pump Station Building previously constructed. The project schedule proposes the project milestones listed in Table 3. Page 11 of 15 3/4/2008 Table 3. Proposed Project Schedule Milestones Milestone Proposed Date Submit Grant Application Initiate Engineering Design Complete Predesign Report Complete Design Finalize Local Funding Plan Issue Invitation to Bid for Construction Award Construction Contract, Phase I Notice to Proceed for Construction Phase I Substantially Complete Complete System Performance Report Commence Construction of Phase II Phase II Substantially Complete March 17, 2008 April 7, 2008 June 13, 2008 August 8, 2008 August 22, 2008 November 14, 2008 December 26, 2008 March 20, 2009 August 7, 2008 December 18, 2009 March 15, 2010 June 4, 2010 VII. Employment and Contracting Compliance Policy Statements Both the Town and the District have employment and human relations policies which are consistent with state and federal requirements. These include the following policies: • Equal Opportunity and Minority Contractor • Drug free workplace • Employment of Illegal Aliens Both agencies require that the policy be received, read, and understood by all employees, as evidenced by their signature on a copy of the policy which is maintained in personnel records. A copy of each agency’s policies on these important items is available upon request. Pa g e 1 2 o f 1 5 3 / 4 / 2 0 0 8 Fi g u r e 2 . P r o p o s e d P r o j e c t S c h e d u l e Pa g e 1 3 o f 1 5 3 / 4 / 2 0 0 8 Fi g u r e 3 . S i t e P l a n Pa g e 1 4 o f 1 5 3 / 4 / 2 0 0 8 F i g u r e 4 . C o n s t r u c t i o n P h a s i n g P l a n Page 15 of 15 3/4/2008 END OF DOCUMENT END NOTES: 1 U.S. Geological Survey records for past 61 years. Obtained online on February 29, 2008 at http://waterdata.usgs.gov/nwis/uv?09070000 2 U.S. Geological Survey records for past 8 years. Obtained online on February 29, 2008 at http://waterdata.usgs.gov/nwis/uv?09067020 3 U.S. Geological Survey records for months of September and October over past 8 years; minimum here is listed at 10th percentile values of daily flow rate data. Obtained online on February 29, 2008 at http://waterdata.usgs.gov/nwis/uv?09067020 4 The Town of Avon began purchasing wind-generated electricity (not credits) directly from Holy Cross Energy in January 2008, reducing their carbon footprint to less than 50% of 2007 levels. Managing carbon footprint and energy consumption is a key goal of the Town of Avon. See Avon’s Climate Action Plan, SGM, 2007. 5 This assumption will be tested during the engineering design phase. 6 Assumes a coefficient of power of approximately 3.0.