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Biosolids TreatmentTHE CITY OF DUBUQUE Masterpiece on the Mississippi Dubuque All-American City 2007 TO: The Honorable Mayor and City Council Members FROM: Michael C. Van Milligen, City Manager SUBJECT: WPCP Facility Planning Recommendation for Biosolids Treatment DATE: May 15, 2008 Water Pollution Control Plant Manager Jonathan Brown is recommending that the City replace the biosolids management component of the Water Pollution Control Plant. The existing process is incineration of the biosolids. The recommendation is to replace incineration with anaerobic digestion, complete the project in one phase, and to set a public hearing on the decision for July 7, 2008. The direction of the City of Dubuque's WPCP has been established as a high priority by the City Council. A process of facility planning and Request for Proposals for the Water Pollution Control Facility Plan were approved by the City Council on February 5, 2007. Consultant selection to prepare the Facility Plan was approved by City Council in May 2007 and Strand Associates of Madison WI was contracted to proceed with planning. Nine options were considered in this year-long study and planning process. Public input was encouraged, including a meeting with representatives of the business community on April 4, 2008, and three public information meetings with one on October 9, 2007, and two on December 12, 2007. A Work Session was held with the City Council on April 14, 2008, to review the options. The current residuals management system includes primary sludge storage, waste activated sludge storage, blended sludge mixing, centrifuge dewatering, dewatered cake conveying and pumping, fluid bed sludge incineration and ash ponds. The incineration facilities are nearly 40 years old and have undergone some upgrades. The dewatering facilities are approximately 15 years old. Of the two incinerators the one equipped with a heat recuperator is by far the most efficient with the ability to dispose of large amounts of biosolids with less input of auxiliary fuel. At the time of their construction a life span of twenty to thirty years was expected. Since then it has been shown that life cycles can exceed these estimates by a considerable amount. The incinerators in their current configuration are very near the end of their useful life and are becoming increasingly less reliable. No matter what method of biosolids management is selected the incinerators will be 45 years old or more by the time a new process is in place. The question is not whether the city should do something but rather what is it the city is going to do. The recommended option is anaerobic digestion. Anaerobic digestion has been used for decades to stabilize sludge prior to land application of the digested sludge. Implementation of anaerobic digestion would require the construction of four new anaerobic digesters and a central control building, likely adjacent to Julien Dubuque Drive on the west side of the existing Water Pollution Control Plant site. Each digester would be approximately 70-feet in diameter and 30 feet tall. A small structure would be constructed to temporarily store biosolids, and disposal would be by contract hauling to an off-site storage facility and ultimately to agricultural land application. The anaerobic digestion process produces biogas, which contains about 60 to 65 percent methane and can be collected and burned to provide heat for boilers or fuel for electricity and heat co-generation. The anaerobic digestion process requires heat to maintain temperatures in the digestion tanks, and this heat consumes a significant amount of the biogas produced in the process. Analysis of anticipated biogas production rates indicates that the biogas produced in the process will exceed the digester heating requirements even under the coldest weather conditions at current and future design loadings. Even though Jonathan Brown is recommending the use of biogas for electrical generation, I am recommending that how this biogas is used will be decided through the design process. Of the nine options studied three were chosen for further analysis based on initial capital costs, operating costs, and non-monitory issues including odor potential and other environmental issues. The following gives a breakdown representing the capital costs, operating costs and present worth analysis of these three biosolids management options: Operations Capital & Maintenance 30yr-Present Worth Anaerobic $26,788,000 $791,000 $44,769,000 Digestion Incineration $18,203,000 $933,000 $46,906,000 (Lime Backup) Incineration $15,717,000 $958,000 $56,564,000 (Inc back-up) You will see that anaerobic digestion has the highest initial capital costs at $26,788,000, but has the lowest annual operating and maintenance costs at $791,000. Most importantly, if you look over the 30 year life of the anaerobic digestion option, it proves to be the least expensive option at $44,769,000, compared to a range of costs of $47 million to $56.5 million to maintain incineration. The following points led to the selection of anaerobic digestion with land application as the preferred alternative: 1. Although the initial capital costs are higher for digestion over the incineration options, the twenty year present worth values are similar and the thirty year present worth analysis show that digestion is favored. 2. The digestion process will use considerably less energy, including electricity and auxiliary fuel, for operation. Energy costs are a main component of wastewater treatment operating costs, and lower energy use will lead to a more stable and predictable rate structure for future years. 3. The real possibility of not only lowering energy use but also utilizing excess biogas to produce energy will further reduce the City of Dubuque's energy use and, therefore, its carbon footprint. 4. The digestion option will provide a forty year solution for biosolids management, while proceeding with one of the incineration options will only provide a 15-year solution. The incineration options will require the process of selecting a biosolids management plan to begin again after 10 to 15 years. 5. The incineration process completely combusts the biosolids, producing an inert ash and carbon dioxide. With incineration there is no concern over perceived problems relating to land application of biosolids. However there will always be issues relating to the air emissions of compounds of nitrogen (NOX) and sulfur (SOX), along with the emission of whatever mercury may be present in the sludge. Incineration will also have a larger release of carbon dioxide due to the fact that a greater amount of energy is required to operate the process. 6. Land application of biosolids has a long and successful history in the State of Iowa and much of the Midwest. There have been reports of problems in some areas, but most of these can be traced to poor management of the process and in some cases fraudulent activities. 7. The method of digestion proposed would produce Class I biosolids (the highest quality) that has the greatest flexibility in terms of its ultimate use. The biosolids would also be usable in a compost operation or as a soil conditioner for parks and forests. In more heavily populated urban areas there is a concern with the long hauling distances required to find suitable agricultural land for application. That is not an issue for Dubuque. In addition to this concern, many if not most of the large older plants with anaerobic digestion are not producing a Class I product, but rather a Class II product. There is the perception of some people in areas where Class II biosolids are being land applied that this activity is dangerous and a detriment to the land and environment. In many respects these perceptions do not exist in Iowa or in states with an agricultural background. Farmers who have used biosolids for soil conditioning know that yields are increased, the tilth of the soil may be improved, and fertilizer costs can be lower. 8. Overall, anaerobic digestion selection is the more `Green' alternative. It promotes the basic concept of reduce, reuse and recycle as compared to incineration, which is only a disposal option. Digestion is the most sustainable option due to its use of less energy to operate, the production of energy, and a usable product in the form of biosolids for composting and/or land application. The next question that needs to be decided is whether the overall project should be completed in one or two phases. The only apparent advantage to a two-phase project is that the impact to the rate payers could be spread out over a longer period of time. This does not alter the fact that the overall costs, and therefore the ultimate total rate increase, will be higher using atwo-phase approach. It is estimated that using a two phase versus a single phase would increase the overall project costs between four and five million dollars. There are increased costs by having two design contracts, two construction bidding processes and the increased costs of materials due to inflation. Water Pollution Control Plant Manager Jonathan Brown is recommending that the project be completed in one phase. This project will be funded through a loan from the State of Iowa Revolving Loan Funds, which offers 0% interest on the design loan and a below market interest rate of 3.25% for the construction loan. Anaerobic digestion with land application completed in one phase would have the following impact on City sewer rates for the design and construction financing alone: FY10 FY11 FY12 FY13 FY14 8% 7% 12% 13% 11% The cumulative increase in rates over this five-year period is 51 % for the design and construction financing alone. In Fiscal year 2009, Dubuque maintained its position as the second lowest sewer rate of the ten cities in the State of Iowa with a population over 50,000. Sanitary Sewer Comparison Sanitary Sewer Rate Comparison for Average User City FY09 Iowa City $36.08 Sioux City $27.04 Des Moines $26.78 West Des Moines $24.50 Council Bluffs $20.64 Davenport $20.63 Ames $19.99 Waterloo $18.95 Dubuque $18.05 Cedar Rapids $16.80 Average Without Dubuque $23.49 The highest ranked city (Iowa City) is 100% higher than Dubuque's rate, and the average is 30.1 % higher than Dubuque. In addition, many of the larger cities in Iowa have planned Water Pollution Plant Upgrades that will require significant future rate increases. These cities include Davenport, Cedar Rapids, Sioux City, Council Bluffs, and Ames. In summary, the recommendation is anaerobic digestion with land application because: 1. Best long term economic solution -initial higher costs but lower over life of system 2. Lower energy costs which will lead to greater rate stability -less vulnerability to increasing costs of energy 3. Lower carbon footprint -will lessen Dubuque's impact on the global climate 4. Longer term solution for biosolids management -the decisions made now will impact Dubuque citizens for the next forty years 5. More closely fits in the City of Dubuque's commitment to being a Green and a Sustainable community. I respectfully recommend Mayor and City Council approval of the recommendation to choose the anaerobic digestion process for biosolids management at the Water Control Plant with the project to be completed in a single phase, with the use of biogas from the process to be decided at a later date through the design process. Michael C. Van Milligen MCVM/jh Attachment cc: Barry Lindahl, City Attorney Cindy Steinhauser, Assistant City Manager Jonathan Brown, Water Pollution Control Plant Manager THE CITY OF DUBUQUE Masterpiece on the Mississippi Dubuque All-American City 2007 TO: Michael C. Van Milligen, City Manager FROM: Jonathan R. Brown, WPCP Manager SUBJECT: WPCP Facility Planning Recommendation for Biosolids Treatment DATE: May 13, 2008 INTRODUCTION The purpose of this memo is to review the facility planning process to this date, analyze biosolids management options and provide a recommendation for biosolids management and phasing of the project. A proposed schedule for needed activities to move the project forward is also included with the recommendation. BACKGROUND The City of Dubuque operates a wastewater treatment plant providing secondary treatment for residential, commercial, and industrial wastewaters. The treatment facilities are complex, energy intensive and involve high replacement costs as units reach the end of their useful lives. The original facilities were designed and built over forty years ago and updated in 1994. The need to replace plant components and the desire to reduce plant operating costs prompted the City to prepare a Facility Plan to identify the best alternatives for sludge handling, biological wastewater treatment, alternative disinfection methods, and to review other plant needs. The direction of the City of Dubuque's WPCP has been established as a high priority by the City Council. A process of facility planning was approved and RFP's for the Water Pollution Control Facility Plan were submitted to council on February 5, 2007. Consultant selection to prepare the Facility Plan was approved by City Council in May 2007 and Strand Associates of Madison WI was contracted to proceed with planning. In order to complete the facility plan it is necessary at this time to provide a recommendation for biosolids management. The question of appropriate biosolids management was the key driving factor in the initiation of the facility planning process. To make that selection it is important to understand how we manage sludge now, what options were considered and how these alternatives compare in terms of costs, reliability, "green issues," and other measures. -1- DISCUSSION The current residuals management system includes primary sludge storage, waste activated sludge storage, blended sludge mixing, centrifuge dewatering, dewatered cake conveying and pumping, fluid bed sludge incineration (two units, one with a recuperator), and ash ponds. The incineration facilities are nearly 40 years old and have undergone some upgrades. The dewatering facilities are approximately 15 years old. Of the two incinerators the one equipped with the recuperator (north incinerator) is by far the most efficient with the ability to dispose of large amounts of biosolids with less input of auxiliary fuel. At the time of their construction a life span of twenty to thirty years was expected. Since then it has been shown that life cycles can exceed these estimates by a considerable amount. The incinerators in their current configuration are very near the end of their useful life and are becoming increasingly less reliable. No matter what method of biosolids management is selected the incinerators will be 45 years old or more by the time a new process is in place. The question is not whether the city should do something but rather what is it the city is going to do. Description of Alternatives The following residuals management (RM) alternatives were included in the initial evaluation and are described below: • RM1 Two incinerators o RM1a Major rehabilitation of both existing incinerators. o RM1b Major rehabilitation of one incinerator; no rehabilitation of the second unit. ^ RM2 One Incinerator with Lime Stabilization Backup o RM2a Major rehabilitation of one incinerator with lime stabilization for backup. o RM2b One new incinerator with lime stabilization for backup. • RM3 Lime stabilization with agricultural land application. ^ RM4 Anaerobic digestion with agricultural land application. ^ RM5 Anaerobic digestion with composting. RM6 Anaerobic digestion with drying and agricultural land application. ^ RM7 Drying with agricultural land application. Of the nine options studied three were chosen for further analysis based on initial capital costs, operating costs, and non-monitory issues including odor potential and other environmental issues. The facility plan as completed by our consultants will give a detailed analysis of each issue. RM1b. Maior rehabilitation of one incinerator no rehabilitation of the second unit. This would include a major rebuild of the north incinerator with the south incinerator continuing as a standby without any upgrades. This option should be considered to have no more than a 10 to 15 year life and would require either significant incinerator -2- upgrades within that time frame or a change to a different solids management alternative, such as anaerobic digestion. RM2a. Maior rehabilitation of one incinerator decommissionina of the second unit with lime stabilization for backup. This alternative includes a major rehabilitation of the south incinerator and demolition of the north. Aback-up lime stabilization system would be installed to provide Class biosolids for times when the incinerator is off-line. It was assumed that the lime system will be utilized for one month each year to allow maintenance of the incinerator. It was also assumed that these biosolids would be contract hauled to agricultural sites or other third-party provided off-site storage on an as needed basis. A unit cost of $28/wet ton was assumed, which is significantly higher than comparable off-site storage and land application costs in the Dubuque area. The higher costs were used since the land application operations will be intermittent and could be at irregular intervals. Both of the incinerator options would require significant modifications to the manner of waste activated sludge (WAS) management. In order to operate the incinerators efficiently and keep needed throughput high some form of WAS reduction is required for this alternative. WAS reduction could be implemented by any of the following methods: • Operating the activated sludge systems at a longer sludge age to reduce the observed biological yield. This will require more oxygen for endogenous decay of the biological sludge. In addition, the plant has experienced filamentous problems when operating at longer sludge ages, so additional controls would be required to manage filamentous bulking events. • Constructing aerobic digestion facilities for WAS. The existing WAS holding tank only provides a detention time of 4.5 days at the future design loadings. An additional detention time of about 15 days would require a tank volume of 1.6 million gallons and significant blower horsepower to provide adequate aeration. Siting such a tank at this site will be difficult. • Installing a WAS minimization system that uses ozone to lyse cells and reduce WAS by as much as 80 percent. The additional oxygen required to oxidize the soluble BOD generated from cell rupture is met by the ozone reduction to oxygen. There are a few companies marketing this technology, though there are no known full- scale installations in the United States. This system would also utilize additional oxygen in the ozone generator. The construction of aerobic digestion facilities is not deemed to be feasible without sacrificing the remaining space on the site. Installing an ozone sludge minimization system may be feasible, but will require considerably more evaluation prior to making the decision to install such a system. Operating the activated sludge system at a longer sludge age is feasible, since the third activated sludge treatment train is available rather than operating with only two trains of aeration basins. This alternative is included for this evaluation. However, should one of the incinerator alternatives be selected, the potential to use the ozone WAS minimization technology may be further considered. -3- RM4. Anaerobic digestion with agricultural land application Anaerobic digestion has been used for decades to stabilize sludge prior to land application. Temperature phased anaerobic digestion (TPAD) is a high-rate digestion system that stabilizes biosolids in a two-step process where the sludge is first held for a minimum of five days under thermophilic conditions (131 °F) before being held for a minimum of 10 days under mesophilic conditions (95°F).. (Anaerobic digestion followed by composting has the same capital cost and nearly the same operating cost and should be considered equivalent to digestion with land application. However, there are more unknowns, permitting considerations, and additional capital and operating cost components that maybe required to implement composting operations. Development of composting operations in the future should be pursued to enhance the overall management flexibility.) Implementation of anaerobic digestion would require the construction of four new anaerobic digesters and a central control building, likely adjacent to Julien Dubuque Drive on the west side of the site. Two of the digesters would typically operate as thermophilic digesters with fixed covers, and the other two would operate as mesophilic digesters with gas holding covers. Each digester would be approximately 70-feet in diameter and 30 feet tall. The digestion system would normally operate in the TPAD mode, with sludge being delivered from the sludge blending tank to the thermophilic digesters first and then to the mesophilic digesters. From there, stabilized biosolids would be pumped to the centrifuges for dewatering. A small structure would be constructed to temporarily store biosolids, and disposal would be by contract hauling to an off-site storage facility and ultimately to agricultural land application. A unit cost of $20/wet ton for biosolids hauling, contract, and disposal was assumed based on discussions with two local contractors. In addition, a lease fee for athird-party owned storage facility would be added, with an option to purchase the facility after a 5 or 10 year period. The anaerobic digestion process produces biogas, which contains about 60 to 65 percent methane and can be collected and burned to provide heat for boilers or fuel for electricity and heat co-generation. The anaerobic digestion process requires heat to maintain temperatures in the digestion tanks, and this heat consumes a significant amount of the biogas produced in the process. Analysis of anticipated biogas production rates indicates that the biogas produced in the process will exceed the digester heating requirements even under the coldest weather conditions at current and future design loadings. Biogas reuse would include one of the following options: Option 1: Burn the biogas in a boiler to produce heat for the digestion process and for building heating needs. This option would utilize a portion of the biogas to generate heat, and the excess biogas would be flared. No supplemental natural gas would be required on a year-round basis to heat the digester or the new digester control building. -4- Option 2: Use the biogas to generate electricity and recover waste heat to provide some of the heating needs of the digestion process. Option 2 uses nearly all of the gas year-round to produce electricity. At the current average loadings, approximately 250 to 275 kW (335 to 370 hp) of electricity could be produced on a continuous basis. At future design loadings, approximately 400 kW (535 hp) could be generated. Option 3: Sell the biogas to local industry. The following gives a breakdown representing the capital costs, operating costs and present worth analysis of these three biosolids management options. Operations Capital &Maintenance 30yr-Present Worth Anaerobic $26,788,000 $791,000 $44,769,000 Digestion Incineration $18,203,000 $933,000 $46,906,000 (Lime Backup) Incineration $15,717,000 $958,000 $56,564,000 (Inc back-up) The carbon footprint of Incineration options versus digestion is a follows; Incineration Options Anaerobic Digestion Lbs CO2/year 2,619,000 968,000 PROCESS SELECTION Based on the review of the three biosolids management options considered, I recommend the Anaerobic Digestion process with contract land application as the choice for biosolids management. The following points were considered in this selection: 1. Although the initial capital costs are higher for digestion over the "bare minimum" incineration options, the twenty year present worth values are similar and the thirty year present worth analysis show that digestion is favored. 2. The digestion process will use considerably less energy, including electricity and auxiliary fuel, for operation. Energy costs are a main component of wastewater treatment operating costs, and lower energy use will lead to a more stable and predictable rate structure for future years. 3. The real possibility of not only lowering energy use but also utilizing excess biogas to produce energy will further reduce the City of Dubuque's energy use and, therefore, its carbon footprint. -5- 4. The digestion option will provide a forty year solution for biosolids management, while proceeding with one of the incineration options will only provide a +/- 15- year solution. The incineration options will require the process of selecting a biosolids management plan to begin again after 10 to 15 years. 5. From an environmental standpoint I believe both methods of biosolids management have merits and detractions. As in many situations, there is not a single solution that solves all problems perFectly without creating new issues to manage. It is important that the process selected is a good fit for the community while understanding that the same solution may not be the best for another community. The incineration process completely combusts the biosolids, producing an inert ash and carbon dioxide. With incineration there is no concern over perceived problems relating to land application of biosolids. However there will always be issues relating to the air emissions of compounds of nitrogen (NOX) and sulfur (SOX), along with the emission of whatever mercury may be present in the sludge. Incineration will also have a larger release of carbon dioxide due to the fact that a greater amount of energy is required to operate the process. 6. Land application of biosolids has a long and successful history in the State of Iowa and much of the Midwest. There have been reports of problems in some areas, but most of these can be traced to poor management of the process and in some cases fraudulent activities. 7. The method of digestion we are proposing would produce Class I biosolids (the highest quality) that has the greatest flexibility in terms of its ultimate use. The biosolids would also be usable in a compost operation or as a soil conditioner for parks and forests. In more heavily populated urban areas there is, I believe, a legitirriate concern with the long hauling distances required to find suitable agricultural land for application. In addition to this concern, many if not most of the large older plants with anaerobic digestion are not producing a Class I product, but rather a Class II product. There is the perception of some people in areas where Class II biosolids are being land applied that this activity is dangerous and a detriment to the land and environment. In many respects these perceptions do not exist in Iowa or in states with an agricultural background. Farmers who have used biosolids for soil conditioning know that yields are increased, the tilth of the soil may be improved, and fertilizer costs can be lower. 8. Overall I believe that the digestion selection is the more `Green' alternative. It promotes the basic concept of reduce, reuse and recycle as compared to incineration, which is only a disposal option. Digestion is the most sustainable option due to its use of less energy to operate, the production of energy, and a usable product in the form of biosolids for composting and/or land application. The City of Dubuque has made a commitment to become a Green City and the selection of the digestion process more closely fits this commitment and does so while being the most economical over the long term. -6- PHASING The next question that needs to be decided is whether the overall project should be completed in one or two phases. The only advantage that I see to a two-phase project is that the impact to the rate payers could be spread out over a longer period of time. This does not alter the fact that the overall costs, and therefore the ultimate total rate increase, will be higher using atwo-phase approach. It is estimated that using a two phase versus a single phase would increase the overall project costs between four and five million dollars. There are increased costs by having two design contracts, two construction bidding processes and the increased costs of materials due to inflation. There has been some concern expressed that a single large project might not attract the same number of qualified contractors in the bidding process. I do not believe that will be the case due to the fact that, even with the two-phase approach, each of the jobs would be in the 15 to 30 million dollar range. The same contractors interested in a 45 million dollar bid would also be interested in a 15 or 30 million dollar job. There are also an adequate number of electrical and mechanical subcontractors capable of completing a larger project such that there is significant secondary competition at that level to control costs. If there is a premium to the bidding process due to a potential lack of competition for a single large project, the amount saved by completing the project in one phase versus two phases would more than make up the difference. The additional costs to provide for gas clean up and electrical energy production from the biogas has not been included in the estimate of costs for the digestion process. It would be feasible to use part of the money saved by doing a single phase project to pay for electrical generating capabilities. By producing electrical energy in the process we can further lower the annual operating costs and further reduce the carbon footprint of the plant. We are currently working with Strand Associates to investigate alternate energy sources for the operation of the treatment plant and the use of biogas for energy production is a leading candidate. FUNDING This project is recommended to be financed by State Revolving Loan funds, which offer 0% interest on the design loan and abelow-market interest rate of 3.25% for the construction loan. The impact on rates for construction of the Water Pollution Plant Upgrade is as follows (see attached graphs): Anaerobic Digestion with Land Application -Single Phase (Attachments I & II) FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 0% 8% 7% 12% 13% 11% -7- Anaerobic Digestion with Land Application -Two Phases (Attachments III & IV) FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 FY 2016 0% 5% 6% 8% 9% 14% 8% 6% The impact on rates for construction of the Water Pollution Plant Upgrade and the normal planned operating increases are as follows (see graphs attached): Anaerobic Digestion with Land Application -Single Phase (Attachment V) FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 0% 13% 14% 17% 18% 16% Anaerobic Digestion with Land Application -Two Phases (Attachment VI) FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 FY 2016 0% 10% 11% 13% 14% 19% 13% 11% In Fiscal Year 2009, Dubuque will still maintain the position of second lowest sewer rate of the ten cities in the State of Iowa with a population over 50,000 as shown in the following table: Sanitary Sewer Comparison Sanitary Sewer Rate Comparison for Average User City FY08 FY09 Iowa City $34.36 $36.08 Sioux City $22.45 $27.04 Des Moines $26.78 $26.78 West Des Moines $22.20 $24.50 Council Bluffs $17.20 $20.64 Davenport $19.19 $20.63 Ames $18.45 $19.99 Waterloo $18.95 $18.95 Cedar Rapids $14.91 $16.80 Average Without Dubuque $21.61 $23.49 The highest ranked city (Iowa City) is 100% higher than Dubuque's rate, and the average is 30.1 % higher than Dubuque. -8- In addition, many of the larger cities in Iowa have planned Water Pollution Plant Upgrades that will require significant future rate increases. These cities include Davenport, Cedar Rapids, Sioux City, Council Bluffs, and Ames. SCHEDULE The following schedule is proposed in order to meet a July 7th public hearing date. The timeline of events from May 26th to the June 6th advertising„of the public hearing date is tight and requires that formal approval of the facility plan by the City Council be made at the June 2nd council meeting. In all there will be three opportunities to reflect on the facility plan and either approve this recommendation or request an alternative. If an alternative course of action is requested, there would perhaps be as much as a seven to eight week timeframe to submit an alternate proposal. If council decides to table the selection process to allow for further discussion or public input, the timeline for activities would be changed to accommodate the public hearing requirements. In order for the process to work, the planning document needs to be completed, including the recommendation for the biosolids handling component, and available for public comment at least thirty days prior to the public hearing. Mav 19 Council Meeting: (1) Council selects one of the biosolids alternatives based on recommendation from City Staff (2) Council decides whether to use 1 or 2 construction phases (3) Council decides whether to use the State Revolving Loan Program or to fund the project elsewhere. (4) Council sets Public Hearing date By Mav 26: Strand completes facilities plan report, required forms, and supplemental information; submits all information to the City. A few of the forms will require authorized signatures from the City. June 2 Council Meeting: (1) Council formally approves facilities plan (2) Council authorizes Strand to submit the plan to IDNR (3) If anything has changed with the schedule, a new public hearing date may need to be selected. By June 6: City advertises public hearing and provides proof of publication to Strand for submittal to IDNR. During the month of June, IDNR will be conducting initial reviews of the plan and environmental issues. Prior to the hearing, they will develop an environmental information document for inclusion at the hearing. -9- July 7 Public Hearing: The purpose of the Public Hearing is to inform our citizens of the proposed action, discuss cost and user fees associated with the project, and to address citizen's concerns, if any, with the plan. At this point in the process we would also ask the council's approval to proceed with Request for Proposals (RFP) for the selection of design engineers. In projects of this type it is typical that the design firm also provides construction management services. In addition to construction services from the design firm Steve Brown, Project Manager in the City of Dubuque Engineering Department, will be assisting in the management of the process. Due to the size of this project an additional part-time employee will be requested for the engineering department to assist in project management details for this and other large projects the City will be working on during this time period. RECOMMENDATION I offer the following in summary of the recommendations given in the body of the memo; A. The selection of Anaerobic Digestion with Land Application as the choice for biosolids management. 1. Best long term economic solution -initial higher costs but lower over life of system 2. Lower energy costs which will lead to greater rate stability -less vulnerability to increasing costs of energy 3. Lower carbon footprint -will lessen Dubuque's impact on the global climate 4. Longer term solution for biosolids management -the decisions made now will impact Dubuque citizens for the next forty years 5. More closely fits in the City of Dubuque's commitment to being a Green and a Sustainable community. B. Single phase construction 1. Lower overall project costs - no true benefit from a two phase project 2. Quicker return on investment for the project 3. Allows flexibility to pursue alternate energy plans C. Include the option of electrical energy generation in the design of WPCP improvements As stated earlier I believe that the digestion selection is the more `Green' alternative. It promotes the basic concept of reduce, reuse and recycle as compared to incineration, which is only a disposal option. Digestion is the most sustainable option due to its use of less energy to operate, the production of energy, and a usable product in the form of biosolids for composting and/or land application. The City of Dubuque has made a commitment to become a Green City and the selection of the digestion process more -10- closely fits this commitment and does so while being the most economical over the long term. ACTION REQUESTED I respectfully request that the City Council approve the following items to complete the facility plan and move forward with the WPCP improvements; (1) The selection of Anaerobic Digestion with Land Application as the choice for biosolids management. (2) A single phase for design and construction. (3) Authorize the application for the use of the State Revolving Loan Program to fund the project (4) Set July 7th as the date for the Public Hearing Attachment cc: Cindy Steinhauser, Assistant City Manager Jenny Larson, Budget Director -11- Attachment I Anaerobic Digestion with Land Application -Single Phase Cumulative Impact on Rates -Construction Only 60% 51% 50 40% 40 27% 30 20% 15% 8% 10% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 Attachment II Anaerobic Digestion with land Application -Single Phase Impact on Rates -Construction Only - 51% Increase Over 5 Years 14% 13% 12% 12 % 11% 10% 8% 8 % 79, 6% 4% 2% 0% 0% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 Attachment III Anaerobic Digestion with Land Application -Two Phase Cumulative Impact on Rates -Construction Only 60 56% 50% 50 42% 40% 0 30 19% 20 11% 10 % 5% 0% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 FY 2016 FY 2017 Attachment IV Anaerobic Digestion with Land Application -Two Phase Impact on Rates -Construction Only - 56% Increase Over 7 Years 14% 12% 10% 8% 6% 4% 2% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 FY 2016 FY 2017 Attachment V Anaerobic Digestion with Land Application -Single Phase Impact on Rates -Construction + Operating 18 % 17% 1690 16% 14% 1390 14% 12% 10% 990 8% 6 % 590 4% 2% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 Attachment VI Anaerobic Digestion with Land Application -Two Phase Impact on Rates -Construction + Operating 20% 18% 16% 14% 12% 10% 8% 6% 4% 2% 0% FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 FY 2016 FY 2017 Page 1 of 1 Mike Van Milligen -Sludge Handling From: Mike Van Milligen To: GVanDrie@aol.com Date: 5/13/2008 3:45 PM Subject: Sludge Handling CC: Brown, Jonathan Attachments: 08_05_13 City Council Referrals_Gerhardt Van Drie.pdf Dear Mr. VanDrie, Thank you for your April 21, 2008 e-mail on sludge disposal. The attached information, along with your letter, will appear on the May 19, 2008 City Council Agenda. The meeting is held in the City Council Chambers on the second floor of the Historic Federal Building, 350 West 6th Street, Dubuque, Iowa. Sincerely, Michael C. Van Milligen Dubuque City Manager City of Dubuque 50 West 13th Street Dubuque, Iowa 52001 Telephone: 563-589-4110 Fax: 563-589-4149 buque: Masterpiece on the Mississippi Before printing this e-mail, please determine if it is truly necessary file://C:\Documents and Settings\jhilkin\Local Settings\Temp\XPgrpwise\4829B7A8DBQ_DODB... 5/15/2008 THE CITY OF DUBUQUE Masterpiece on the Mississippi Dubuque All-American City 2007 TO: Michael C. Van Milligen, City Manager FROM: Jonathan R. Brown, WPCP Manager SUBJECT: City Council Referrals DATE: May 13, 2008 INTRODUCTION The purpose of this memo is to respond to the City Council referral regarding comments provided by Gerhardt Van Drie concerning sludge disposal methods. DISCUSSION There are many methods being current{y used and developed for sludge disposal in the United States, one of those is our current method of incineration. Mr. Van Drie infers with his comments that he believes that the incineration of sludge is a serious component of air pollution and presents a danger to the citizens of Dubuque and the surrounding area. I do not agree with his analysis and contend that fluid bed incineration is a very safe way to dispose of biosolids. The parameters under which the process is operated and the air pollution control devices installed ensure that pollution from the process is minimized. This does not mean there is no pollution but that the impacts are minimal. The idea that chemicals in the sewer system are automatically going to end up in the exhaust gases of the incinerator is not correct. The sludge is combusted at a final temperature of over 1600 degrees Fahrenheit followed by wet scrubbing of the exhaust. The organics are destroyed and the metals, except mercury, are tied up in the ash and are inert. Mr. Van Drie's proposal for sludge disposal requires the trenching of raw sludge into land somewhere in the surrounding area. Many cities have used landfills and some times dedicated landfills for sludge disposal. I have some concerns with Mr. Van Drie's approach for sludge disposal in our area. The operation of such a plan would more than likely require raw sludge storage for those periods when the land is frozen or unable to be used, it would require that over 70,000 pounds per day of raw unstable and odorous sludge be hauled out of the valley where the plant is located and trenched into land that the city has purchased solely for its ultimate disposal. Dedicated landfill sites for sludge disposal are required to meet the entire site and construction requirements of solid waste landfills so I believe his costs estimates for disposal may be low. Mr. Van Drie's plan is for disposal only and does not include taking advantage of the energy, nutrients, and soil conditioning opportunities of the use of properly treated biosolids. Some people are opposed to the incineration of sludge, some to land application, some to ocean- dumping, some to landfills and there would be opposition to trenching raw sludge into land in our community. It is not practical to include all potential sludge treatment options in a study and the decision was made to include only those methods that have a proven track record in the industry. Mr. Van Drie may be correct that innovation takes twenty years but I believe it is in the best interest of the City of Dubuque to go forward at this time with proven technologies. Page 1 of 1 Mike Van Milligen - Re: Sludge Handling From: <GVanDrie@aol.com> To: <CtyMgr@cityofdubuque.org> Date: 5/13/2008 7:19 PM Subject: Re: Sludge Handling CC: <GVanDrie@aol.com>, <rdbuol@cityofdubuque.org>, <TEGEA@aol.com>, <bcooper@wcinet.com> Mr. Michael C. Van Milligan, City Manager: I want to briefly reply at the outset to some of Mr. Brown's comments since they are so inappropriate. No. 1: The daily production of 70,000 Ibs of sludge amounts to 35 tons which amount is only about two 20-ton truck loads. No. 2: The proposed trenches can be dug by the excavating equipment, when the ground starts to freeze, in sufficient length to last for the winter. No. 3: If the sludge weighs 100 Ibs per cubic foot then the volume of the daily production of sludge would be 700 cubic feet. A 3-foot wide trench 10 feet deep would accomadate 30 cubic feet of sludge per lineal foot of trench. So about 25 lineal feet of trench is required to be dug per day for the city of Dubuque. This length can be dug in 30 minutes. The excavated soil can cover the sludge in the trenches immediately after it is discharged from the truck. No. 4: He makes no reference to my costs as compared to the options presented in the recent report. Don't costs matter? Three options proposed by the report includes surface land applications for final disposal of sludge. Won't Dubuque County farm neighbors love this!! No. 5: I am receiving information on a site that is large enough for the city of Dubuque to last for 40 years at a cost of $4500 per acre. I have a cost estimate for a new crawler treaded excavator for $52,000. I will receive an estimate shortly on an appropriate truck with sludge handling and hauling equipment. All of the equipment technology proposed to be used has been thoroughly used for many years; so what is new? What is different is that we are making a real attempt to keep the disposal of sewage sludge from polluting the land, water and air. This effort benefits the health and welfare of people and industries and is very cost effective at the same time. Gerhardt Van Drie, R.C.E. Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. file://C:\Documents and Settings\jhilkin\Local Settings\Temp\XPgrpwise\4829E9D7DBQ_DODB... 5/15/2008 Page 1 of 1 Mike Van Milligen -City of Dubuque Sludge Disposal From: <GVanDrie@aol.com> To: <mike.connolly@legis.state.ia.us>, <Pam.jochum@legis.state.ia.us>, <Pat.Murphy@legis.state.ia.us>, <Steven. Lu kin@legis.state. ia. us> Date: 5/14/2008 3:04 PM Subject: City of Dubuque Sludge Disposal CC: <CtyMgr@cityofdubuque.org>, <rdbuol@cityofdubuque.org>, <TEGEA@aol.com>, <GVanDrie@aol.com> Ladies and Gentlemen of the Iowa State Legislature: First all a bit of info about me. I have a B.S. from the U. of Dubuque and a B.S. in civil engineering from Iowa State U. Many years ago, I was the public works director and city engineer of Spencer, IA. My brother Rudy Van Drie, in the "70 was a state representative and state senator in the Iowa State legislature from Ames. I have developed the Van Drie Trenching Process which has the goal of prevention of sludge disposal methods polluting the air, water and land surfaces. The city of Dubuque will need to obtain a permit from the Iowa Department of Natural Resources (DNR) for authority for use of this technology. The Iowa State Legislature will have to include his technology into the current statutes pertaining to disposal of sewage sludge. I am informed that on the staff level at the DNR, Chuck Correl, Bureau Chief for the Water Bureau and Wayne Gieselman, Division Administrator for Environmental Services are people involved with coordinating legislative matters. will keep you posted with the ongoing matters pertaining to the city of Dubuque and this technology. The city council of Dubuque has an item on their agenda pertaining to this matter at their meeting of Monday May 19. Gerhardt Van Drie, R.C.E. EI Segundo, CA 90245 310-322-3258 Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. file://C:\Documents and Settings\jhilkin\Local Settings\Temp\XPgrpwise\482AFF80DBQ_DODB... 5/15/2008 THE CITY OF DUBUQUE Masterpiece on the Mississippi Dubuque All-American City 2007 TO: The Honorable Mayor and City Council Members FROM: Michael C. Van Milligen, City Manager SUBJECT: City Council Referrals DATE: May 15, 2008 Water Pollution Control Plant Manager Jonathan Brown has provided additional information related to the request of Mr. Van Drie. Michael C. Van Milligen MCVM/jh Attachment cc: Barry Lindahl, City Attorney Cindy Steinhauser, Assistant City Manager Jonathan Brown, Water Pollution Control Plant Manager THE CITY OF DUBUQUE Masterpieceon the Mississippi Dubuque All-American City 2007 TO: Michael C. Van Milligen, City Manager FROM: Jonathan R. Brown, WPCP Manager SUBJECT: City Council Referrals DATE: May 15, 2008 INTRODUCTION The purpose of this memo is to provide additional comments in response to Mr. Van Dries communication with council regarding City of Dubuque Sludge Disposal. DISCUSSION In Mr. Van Drie's communication with local legislatures he mentioned a key fact in the selection of sludge disposal methods, that being the method that he is proposing is not approved as a disposal method in the State of Iowa. The method approval process would be quite complex requiring engineering studies, rules modification and then final approval from the legislature and would be a lengthy process. It is important that the City of Dubuque move forward with the planning process using proven technologies that are widely accepted in the State of Iowa. Another point of concern which was not included in my memo to you dated May 13, 2008 is the production of uncontrolled methane by burying untreated sludge. The release of methane from landfills is a major source of greenhouse gases and the methane released from the trenching of raw sludge would be a very large contributor of greenhouse gases to the environment. Questions from Water Pollution Control Work Session April 14, 2008 1. How much KWH does the WPCP use each day? The average demand is 775 KW per day with an average usage of 12,614 KWH per day with approximately 30% of that for incineration. This means per year an electrical usage for incineration of 1,614,598 KWH and for digestion 686,131 KWH per year. Using the EPA model for pounds of CO2 emitted per KWH equals 2,212,000 pounds for incineration and 940,000 for digestion based on electrical use only. The electrical component of carbon dioxide emissions for the treatment of biosolids can be reduced by more than 50% using the digestion process. This could further be reduced if it is feasible to produce electricity from the methane generated in the digestion process. 2. Is there a way to measure particulates in air using either Incineration or Anaerobic Digestion? Where do these particulates go? Particulates are a mixture of solid and liquid particles which can be a byproduct of the combustion process, whether that combustion is the burning of biosolids in an incinerator or the burning of biogas from digestion. The control of particulates is based on the efficiency of the combustion process. If a proper mixture of fuel, heat and oxygen is maintained the occurrence of soot or smoke is very minimal. The operating permit for the incinerators requires that we measure the carbon monoxide (CO) content of the stack gas and that we maintain a low level of carbon monoxide in the process. By keeping a low level of CO we are ensured that there will be minimal production of any particulates of combustion. In the industry these are called particles of incomplete combustion or PICs. The ultimate fate of the PICs will be determined by the size of the particulates; heavy soot will fall to the ground in short order while the lighter smoke will persist in the environment and become a component of local air pollution and perhaps even on a regional basis. We monitor on a continual basis the oxygen, CO, temperature and feed rates of biosolids to the incinerator. By keeping these parameters within the limits of our Clean Air Permit we are assured that we have minimized the production of any PICs. Although not measured directly on a continual basis the parameters we do monitor and control assure us that we are not producing particles of incomplete production. A similar approach is used for the other parameters of concern. In order to receive a Clean Air Permit it is required that extensive stack testing is completed under actual operating conditions. This testing procedure also includes monitoring for metals and organics released during operation. Control parameters are then developed and limits are issued in the operating permit. By maintaining these parameters we are assured that we are minimizing any potential for harmful emissions. The operating Clean Air Permit for the Water Pollution Control Plant was recently reissued and will remain in effect until February 19, 2013. At that point there more than likely will be additional requirements placed on the operation of incinerators but it is difficult to say exactly what these requirements may be. 3. Explain how Green House Gas emissions are the same using Incineration or Anaerobic Digestion? - They are the same from the standpoint that the biosolids are renewable and that each process ultimately converts the carbon in the biosolids to carbon dioxide. The overall emission of C02 however is higher in the incineration process because of the need to use auxiliary fuel in the process and a larger amount of electrical power. Assuming the additional energy comes from fossil fuels then incineration as a process will have a larger emission of carbon dioxide, the main component of greenhouse gases. 4. What is the number of employees needed to operate an Incineration process versus an Anaerobic Digestion process? The current process requires eight operators at the present loading, more if loading would increase significantly. The digestion process would require six to seven operators with no increase if loading increases. This is assuming that the transportation of the biosolids is contracted out. Laboratory, maintenance and administrative levels would remain the same. 5. What is the cost to store bio-gas versus the cost to put this into an electrical grid or put as natural gas? The question of storing biogas for an extended period of time is not feasible. In the past, when compressed digester gas storage was more common, a large gas sphere typically only provided about two days of storage, and anything larger typically wasn't cost effective. In more recent times, gas storage in a dedicated sphere is less common. The capital cost to generate electricity at the plant would include the cost of the generation equipment, gas cleaning equipment, heat recovery systems, and accessories, and would be in the $1.0 to $2.0 million range; a lot will depend on how much the gas will need to be cleaned prior to burning in an engine or microturbine. Since the plant doesn't produce gas now, we can't test it for siloxanes, H2S, etc, and we would need to assume that significant gas cleaning would be required before it could be burned. The capital cost to convert the biogas to near natural gas quality would require similar gas cleaning equipment as producing electricity with the addition of the removal of the carbon dioxide in the gas, and would also be in the $1.0 to $2.0 million range and possibly higher. 6. What are the comparative operating cost of the three options presented (Incineration, Incineration with Lime back-up and Anaerobic Digestion)? Incineration (Refurbish One) $958,000 Incineration with Lime -back up $933,000 Anaerobic Digestion with $791,000 Agricultural Land application 7. What happens in fiscal year 2014 that causes the Anaerobic Digestion method to go up? The debt service for the construction of the anaerobic process kicks in at this time which then requires this amount of rate increase to begin repaying this debt. 8. Of the ten largest cities in Iowa, which ones use Incineration and which ones use Anaerobic Digestion? Cedar Rapids and Dubuque use incineration, Des Moines uses lime stabilization and land application. The other cities use forms of anaerobic digestion and land application. 9. Explain the difference in fuel costs for Incineration versus fuel costs for hauling material from the Anaerobic Digestion process? What is the anticipated cost difference for each method? Both the incineration process and biosolids hauling use diesel fuel in operation. The incineration process assumes 18,260 gallons of diesel per year and diesel fuel for biosolids hauling is estimated at 1256 gallons per year. The incineration process is estimated to use as much as 1486% more diesel fuel as the digestion process. The following table gives an idea of the impact of diesel fuel cost increases on each of the processes. Diesel Costs per gallon Incineration Digestion $3.50 $63910 $4396 $4.00 $73040 $5024 $4.50 .$82170 $5652 $5.00 $91300 $6280 10. The following charts provide information relating to the various biosolids management options reviewed; A. WPCP Upgrade Cost - 30 Year Present Value B. WPCP Upgrade Cost -Current Capital Cost C. WPCP Upgrade Cost -Annual Operating Costs Page 1 of 2 Jeanne Schneider -email for mayor and city council From: <GVanDrie@aol.com> To: <jschneid@cityof dubuque.org> Date: 04/21 /2008 11:49 AM Subject: email for mayor and city council CC: <GVanDrie@aol.com> City Clerk J. Schneider: I sent this email to the city of Dubuque mayor and city council, but it did not go through. Please forward this document to your mayor and city council for me. Many thanks for your courtesies. Gerhardt Van Drie Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos. Forwarded Message: Subj: Sludge handling Date: 4/19/2008 8:59:30 PM Pacific Daylight Time From: GVanDrie To: rdbuol cityofdubuque org~dresnick~a cityofdubuJc ue ora~kbraig~a cityofdubuyue orq;rjones citvofdubuaue CC: GVanDrie, Gvandrie1Ccr~cs.com, vandrie _uci.edu BCC: TEGEA The Honorable Mayor and City Council City of Dubuque Iowa; Greetings. The present methods for disposal of sludge from sewage treatments plants contaminates land, water and the air. You are well aware of the pollution of the Mississippi River from land and water disposal methods. Your city has polluted the air with use of incineration which polluted air can travel for 100's of miles. Chemicals presently dumped in sewer lines endue in the air that people breathe from incineration. Air pollution from China travels to parts of the US. It is possible to avoid contamination of land, water, and air by use of the high volume Van Drie Trenching Process. Trenches can be dug in appropriately chosen ground and immediately covered by the excavated soil. This process will not be workable when sand dunes, or solid rock exists or where the water table is within 15 feet of the ground surface. I made Jonathan Brown, the manager of your sewage treatment plant aware of this technology over a year ago, but as I see now, he has not included this sludge disposal alternative in his recommendations to you. It is very easy to load the dewatered sludge, presently fed to your incinerators, directly to trucks and hauled to appropriate land nearby. In the real world of wastewater treatment in which we live and operate, you will find that consulting engineers and contractors make more money pouring as much concrete as possible. Inefficient technology keeps being used. Others have commented that it may take as long as 20 years to get excellent innovation to be installed. file://C:\Documents and Settings\jschneid\Local SettingslTemplXPgrpwise\480C7F34DB... 04/21/2008 Page 2 of 2 Many years ago when I started as public works director and city engineer for the city of Spencer, Iowa, I found that in the wintertime when the sludge drying beds were filled up and frozen, that the crew would open the valves of the full digesters and discharged liquid sludge to the Little Sioux River. I knew this was wrong to do, so bought a tank truck for hauling liquid digested sludge to frozen corn stalk land. I carried on research work at the Spencer plant that was used at a national conference by an engineer from the Iowa Department of Public Health. I earned a B.S. in natural sciences from the U. of D. in 3 years including teaching engineering drawing and descriptive geometry to returning servicemen of WII during the 3rd year. I also have a civil engineering degree from Iowa State U. and have also earned a masters from the graduate school of political science at Arizona State U. while being chief inspector for the city of Phoenix. What are you going to decided to do for the next 40 years for sewage treatment punt sludge disposal and how much money are you going to blow? 100 acres of land at $40,000 per acre amounts to $ 4 million dollars. After using all of the land, it can be used for some uses such as growing Christmas trees. THE GOAL SHOULD BE NOT TO POLLUTE THE LAND, WATER AND AIR WITH HARMFUL ELEMENTS Gerhardt Van Drie, R.C.E. Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos. file://C:\Documents and Settings\jschneid\Local Settings\Temp\XPgrpwise\480C7F34DB... 04/21/2008