Please note that comment letters submitted to the MPCA do become public documents and will be part of the official public record for this project.

Transcription

1 November 4, 2005 TO: INTERESTED PARTIES RE: Enclosed is the (EAW) for the proposed Elk River Landfill Internal Combustion Engine D, City of Elk River, Sherburne County. The EAW was prepared by the Minnesota Pollution Control Agency (MPCA) and is being distributed for a 32-day review and comment period pursuant to the Quality Board (EQB) rules. The comment period will begin the day the EAW availability notice is published in the EQB Monitor, which will likely occur in the November 7, 2005, issue. Comments will be accepted through December 9, In addition to the EAW, the MPCA s draft Air Emissions Permit will also be available for public comment concurrently. The contact person for the Air Emission Permit is John Chikkala at (651) Comments received on the EAW will be used by the MPCA in evaluating the potential for significant environmental effects from this project and deciding on the need for an Impact Statement (EIS). A final decision on the need for an EIS will be made by the MPCA Commissioner after the end of the comment period. If a request for an EIS is received during the comment period, or if the Commissioner recommends the preparation of an EIS, the MPCA Citizens Board (Board) will make the final decision. The final EIS need decision will also be made by the Board if so requested by the project proposer, other interested parties or MPCA staff and if this request is agreed to by one or more members of the Board or the MPCA Commissioner. The Board meets once a month, usually the fourth Tuesday of each month, at the MPCA office in St. Paul. Meetings are open to the public and interested persons may offer testimony on Board agenda items. A listing of Board members is available on request by calling (651) Please note that comment letters submitted to the MPCA do become public documents and will be part of the official public record for this project. If you have any questions on the EAW, please contact Debra Moynihan of my staff at (651) Sincerely, Richard Newquist Supervisor, Review Unit Review and Operations Section Regional Division RN:jgo Enclosure

2 ENVIRONMENTAL ASSESSMENT WORKSHEET Note to reviewers: The (EAW) provides information about a project that may have the potential for significant environmental effects. This EAW was prepared by the Minnesota Pollution Control Agency (MPCA), acting as the Responsible Governmental Unit (RGU), to determine whether an Impact Statement (EIS) should be prepared. The project proposer supplied reasonably accessible data for, but did not complete the final worksheet. Comments on the EAW must be submitted to the MPCA during the 30-day comment period, which begins with notice of the availability of the EAW in the Minnesota Quality Board (EQB) Monitor. Comments on the EAW should address the accuracy and completeness of information, potential impacts that are reasonably expected to occur that warrant further investigation, and the need for an EIS. A copy of the EAW may be obtained from the MPCA by calling (651) An electronic version of the completed EAW is available at the MPCA Web site 1. Project Title: 2. Proposer: Elk River Landfill, Inc./ Elk River Municipal Utilities 3. RGU: Minnesota Pollution Control Agency Contact Person Debra Walters Contact Person Debra Moynihan and Title Landfill Manager and Title Project Manager Address Highway 169 NW Address 520 Lafayette Road North St. Paul, Minnesota Phone (763) Phone (651) Fax (763) Fax (651) Reason for EAW Preparation: EIS Scoping Mandatory EAW X Citizen Petition RGU Discretion Proposer Volunteered If EAW or EIS is mandatory give EQB rule category subpart number and name: Minn. R subp. 15, Air pollution 5. Project Location: County Sherburne City/Twp City of Elk River 1/4 NW 1/4 Section 3 Township 33N Range 26W Figures Figure 1: Figure 2: Figure 3: Figure 4: Map of Sherburne County showing project location; US Geological Survey Map of the Elk River Landfill; Site Map with location of the LFG-to-Energy Plant; and Map showing residences in the vicinity of the project site. TDD (for hearing and speech impaired only): (651) Printed on recycled paper containing 30% fibers from paper recycled by consumers

3 6. Description: a. Provide a project summary of 50 words or less to be published in the EQB Monitor. Elk River Landfill, in conjunction with Elk River Municipal Utilities (ERMU), proposes to expand a Landfill Gas-to-Energy plant by adding a fourth internal combustion engine (ICE) generator set. The plant currently uses landfill gas to fuel three ICE generator sets and produce electricity that is distributed by ERMU. The new ICE generator set would be installed within the footprint of the LFG-to-Energy building, located on-site of the Landfill. The draft Air Emissions Permit will also be available for public comment concurrently. The contact person for the Air Emissions Permit is John Chikkala at (651) Comments will be accepted on the EAW and on the Air Emissions Permit until December 9, b. Give a complete description of the proposed project and related new construction. Attach additional sheets as necessary. Emphasize construction, operation methods and features that will cause physical manipulation of the environment or will produce wastes. Include modifications to existing equipment or industrial processes and significant demolition, removal or remodeling of existing structures. Indicate the timing and duration of construction activities. Elk River Landfill (ERL or Landfill), in conjunction with ERMU, proposes to expand an existing Landfill Gas-to-Energy plant by adding a fourth ICE generator set. The plant currently uses landfill gas to fuel three ICE generator sets and produce electricity that is distributed by ERMU. The new ICE generator set would be installed within the existing footprint of the building which is located on-site of the Landfill. The proposed increase in air emissions represents the most significant impact associated with this Project. This EAW will address the potential air quality impacts of all four ICE generator sets combined (Project). This Project is a joint venture between three entities: Elk River Municipal Utilities, the Elk River Landfill, and Sherburne County. ERMU is the municipal electric and water utility provider for parts of the City of Elk River and the surrounding area. ERMU owns the building, the ICE engines, all equipment associated with the engines, and will be purchasing the fourth ICE. The ERL supplies the landfill gas (LFG) to the plant, which is used to operate the engines. The ERL also operates the LFG-toenergy plant under an agreement with ERMU. The ERL owns the enclosed flare located adjacent to the LFG-to-energy plant, which will combust any excess gas not used by the engines. Sherburne County provides the financing of the project via landfill abatement funds collected by Sherburne County. ERL is a mixed municipal solid waste (MSW) disposal landfill permitted by the MPCA under Solid Waste Permit SW-74 and a Title V Air Permit ERL is also licensed and permitted by both Sherburne County and the City of Elk River. The Landfill is located 5 miles north of the City of along U.S. Highway 169 on 270 acres of land. Elk River Landfill, Inc. is a wholly owned subsidiary of Waste Management, Inc. ERL is permitted to accept MSW, demolition and construction debris, yard waste for composting, industrial waste in accordance with an MPCA-approved Industrial Solid Waste Management Plan, and processing facility rejects from the Elk River Refuse Derived Fuel (RDF) facility. The location of the Landfill is shown on Figures 1 and 2. 2

4 The ERL has an overall waste disposal capacity exceeding 2,500,000 cubic meters and is, therefore, subject to the New Source Performance Standards (NSPS) for MSW landfills. Under the NSPS and corresponding MPCA regulations, landfills with design capacities greater than 2.5 million megagrams (Mg) and the potential to emit greater than 50 Mg of non-methanogenic organic compounds (NMOCs) per year are required to obtain air permits and operate active gas collection and control systems. ERL s current active gas system consists of 40 extraction wells operating continuously to extract the landfill gas for destruction in three existing ICE generator sets (producing electricity for the community) or in the enclosed flare. The NSPS regulations require 98 percent control efficiency of collected NMOCs. The collected LFG is currently used to fuel three Caterpillar 3516 ICE generator sets for generation of electricity that is distributed to approximately 1,800 homes through the local electric provider, ERMU. Each 1,148 horse power (hp) engine is capable of combusting approximately cubic feet per minute (cfm) of gas, for a total capacity of 900-1,050 cfm. The three ICE generator sets are housed within an existing building (LFG-to-Energy Plant) at the Landfill site as shown in Figure 3. Any excess gas that cannot be managed by the engines is flared in an enclosed 2,000 cfm flare located adjacent to the LFG-to-Energy Plant. The enclosed flare can be modified to increase the capacity to 3,000 cfm. The volume of gas generated at the Landfill is such that there is sufficient gas generated to support the installation of a fourth identical ICE generator set. The new ICE generator set would be installed entirely within the existing LFG-to-Energy Plant building, where space was reserved for the future installation of the fourth engine. A new exhaust stack, reaching a height of 26 feet would be added to match the stacks of the existing three engines. Installation of the new engine would not result in any physical changes to the area around the LFG-to-Energy Plant. Very small quantities of waste material, such as packing material, and scrap pieces of pipe and electrical wiring, would result due to construction associated with the new engine. Installation of the new engine would be completed approximately in April/May of 2006, with the period of construction lasting approximately two months. The Title V Air Permit was issued on March 29, A permit modification is required to allow construction of the fourth ICE generator set and, as a result, increased air emissions from the engines. c. Explain the project purpose; if the project will be carried out by a governmental unit, explain the need for the project and identify its beneficiaries. The purpose of the Project is to provide additional capacity to convert landfill gas into energy. LFG is collected and used as a fuel in the engines to generate an additional kilowatts of electricity (for a total of 2.4 to 3.4 megawatts of electricity) that is in turn distributed by the local electrical utility (ERMU). It is estimated that approximately 2,500 homes will be supplied with electricity from the four engines combined. The Project is used to control landfill gas emissions, while providing a beneficial use in the form of electricity. d. Are future stages of this development including development on any outlots planned or likely to happen? Yes No If yes, briefly describe future stages, relationship to present project, timeline and plans for environmental review. In the future, the ERL may need to expand the current LFG facilities used at the Landfill to control LFG emissions as the Landfill expands into the SDA (see Section 6.e. below). However, if continued development into the SDA is not approved, the ERL does not anticipate that any additional development of the facility s LFG system will be necessary. 3

5 If additional LFG control equipment is necessary for emissions from the SDA, the Project will be evaluated by MPCA to determine if the size and plan for the proposed expansion triggers the need for environmental review (i.e. an EAW). Also, MPCA staff would evaluate the proposal to determine if an expansion of the LFG control equipment would require a major modification of the Landfill s air and solid waste permits. e. Is this project a subsequent stage of an earlier project? Yes No If yes, briefly describe the past development, timeline and any past environmental review. The existing ICE generator sets were permitted in 2001 and began operation in November By limiting the number of sets to three and by taking credit for emission reductions from removing the previously installed Waukesha engine, the potential emissions from the 2001 project were kept below the mandatory EAW threshold of 100 tons/year (Minn. R , subp. 15). However, because construction of the 2001 project commenced less than three years before submittal of the application for the proposed Project, the MPCA considers the two projects to be a phased action as defined in Minn. R , subp. 60. Therefore, the potential emissions increase from all four ICE generator sets exceeds the mandatory EAW threshold requiring the completion of an EAW. ERL is also proposing to expand operations at its existing MSW disposal facility by developing 73.7 acres currently used by an active gravel mining operation located immediately south, adjacent to and as a contiguous part, of the existing Landfill property (Figure 2). The proposed landfill expansion, known as the Southern Development Area (SDA) will provide approximately 15,000,000 cubic yards of additional MSW disposal capacity and extend the operational life of the Landfill years, depending on waste flow quantities. MPCA, the responsible governmental unit, is in the process of preparing an EIS on the proposed SDA. The EIS is being prepared as a mandatory EIS under the requirements of Minn. R , subp. 13 (E) for expansion by 25 percent or more of a previous capacity of a MSW disposal facility for 100,000 cubic yards or more of waste fill per year. The Scoping EAW and Scoping Decision Document for the SDA project were placed on public notice in November The final scope was approved by the MPCA Citizens Board on January 25, The Draft EIS was public noticed on October 24, Completion of the EIS is scheduled for January Project Magnitude Data Total Project Area (acres) NA or Length (miles) NA Number of Residential Units: Unattached 0 Attached 0 maximum units per building 0 Commercial/Industrial/Institutional Building Area (gross floor space): total square feet 0 (no increase in building footprint) Indicate area of specific uses (in square feet): Office NA Manufacturing NA Retail NA Other Industrial NA Warehouse NA Institutional NA Light Industrial NA Agricultural NA Other Commercial (scale house) Building height *20 ft. NA If over 2 stories, compare to heights of nearby buildings *The Project involves the installation of a fourth ICE generator set in the building that houses the existing three ICE generator sets. The existing building was constructed for the installation of the fourth ICE generator set, therefore, no increase in the building s footprint will be necessary. The fourth ICE generator set will consume approximately square feet of the existing floor space. The stack heights of the ICE generators are 26 feet each. A fourth stack of equal height will be constructed next to the existing three stacks. NA 4

6 8. Permits and approvals required. List all known local, state and federal permits, approvals and financial assistance for the project. Include modifications of any existing permits, governmental review of plans, and all direct and indirect forms of public financial assistance including bond guarantees, Tax Increment Financing and infrastructure. Unit of Government Type of Application Status MPCA Title V Air Permit, amendment of permit Submitted City of Elk River Building Permit To be submitted 9. Land use. Describe current and recent past land use and development on the site and on adjacent lands. Discuss project compatibility with adjacent and nearby land uses. Indicate whether any potential conflicts involve environmental matters. Identify any potential environmental hazards due to past site uses, such as soil contamination or abandoned storage tanks, or proximity to nearby hazardous liquid or gas pipelines. The LFG-to-Energy Plant is located on the site of the existing Landfill and within the city limits of the City of Elk River. The proposed Project is compatible with surrounding land uses in the area, which are largely industrial (landfill and mining) in nature. Surrounding land use to the south consists of gravel mining and an asphalt plant. Immediately east of the property lies Trunk Highway 169 (TH 169) beyond which is primarily agricultural land and a portion of the Gravel Mining District. To the west are agricultural lands and the southern portion of the Rice Lake/Tibbits Brook wetland complex. Farmsteads and other single-family residences are scattered throughout the area, west, south and east of the Landfill and Project site. Based on the review of the most recent aerial photograph (2002) available and a site drive through in June 2004, there are approximately 148 residences located within a one-mile radius of the landfill property boundary. An aerial map showing the approximate location of the residences in the vicinity of the project site is presented as Figure 4. The current comprehensive plan for the City of Elk River identifies surrounding land zoning to consist of A1 (Agricultural Conservation) with a Solid Waste Overlay District at the location of the LFG-to-Energy Plant. 10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after development: Before After Before After Types 1-8 wetlands 0 0 Lawn/landscaping 0 0 Wooded/forest 0 0 Impervious Surfaces 0 0 Brush/grassland 0 0 Other 0 0 Cropland 0 0 TOTAL 0 0 There will be no change in cover types as a result of installation of the fourth ICE generator set. The existing building was originally constructed for four ICE generator sets and will not need to be expanded. 11. Fish, Wildlife, and Ecologically Sensitive Resources. a. Identify fish and wildlife resources and habitats on or near the site and describe how they would be affected by the project. Describe any measures to be taken to minimize or avoid impacts. Nearby fish and wildlife resources and habitats include the Rice Lake wetland complex, located approximately 1,200-feet west, and Tibbits Brook, which flows through Rice Lake. The proposed Project is not expected to cause adverse impacts to fish, wildlife, or ecologically sensitive resources. The potential mercury emissions for each ICE generator set is estimated to be 0.02 pounds per year. 5

7 b. Are any state (endangered or threatened) species, rare plant communities or other sensitive ecological resources such as native prairie habitat, colonial waterbird nesting colonies or regionally rare plant communities on or near the site? Yes No If yes, describe the resource and how it would be affected by the project. Indicate if a site survey of the resources has been conducted and describe the results. If the DNR Natural Heritage and Nongame Research program has been contacted give the correspondence reference number. ERBD Describe measures to minimize or avoid adverse impacts. In February 2002, the Natural Heritage and Non-Game Research Program of the Minnesota Department of Natural Resources (DNR) was contacted to determine if any rare plant or animal species or other significant natural features were known to occur near the area of the existing Landfill and proposed SDA expansion area. The Natural Heritage database search identified 5 known occurrences of rare plant communities in the area of the Landfill and proposed SDA (Reference # ERBD ). However, since the construction of the fourth ICE generator set would take place within an existing building located on-site of the existing Landfill, no impacts are anticipated to any sensitive, threatened or endangered species that might be located near the Project area (per telephone contact with Sarah Hoffmann, Endangered Species Review Coordinator on October 24, 2005.) 12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration (dredging, filling, stream diversion, outfall structure, diking, and impoundment) of any surface waters such as a lake, pond, wetland, stream or drainage ditch? Yes No If yes, identify water resource affected. Describe alternatives considered and proposed mitigation measures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the water resources affected are on the PWI. 13. Water Use. Will the project involve installation or abandonment of any water wells, connection to or changes in any public water supply or appropriation of any ground or surface water (including dewatering)? Yes No If yes, as applicable, give location and purpose of any new wells; public supply affected, changes to be made, and water quantities to be used; the source, duration, quantity and purpose of any appropriations; and unique well numbers and DNR appropriation permit numbers, if known. Identify any existing and new wells on the site map. If there are no wells known on site, explain methodology used to determine. 14. Water-related land use management districts. Does any part of the project involve a shoreland zoning district, a delineated 100-year flood plain, or a state or federally designated wild or scenic river land use district? Yes No If yes, identify the district and discuss project compatibility with district land use restrictions. 15. Water Surface Use. Will the project change the number or type of watercraft on any water body? Yes No If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding or conflicts with other uses. 16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: NA acres; NA cubic yards. Describe any steep slopes or highly erodible soils and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after project construction. All of the construction would take place within the existing LFG-to-Energy Plant building. 6

8 17. Water Quality - Surface Water Runoff. a. Compare the quantity and quality of site runoff before and after the project. Describe permanent controls to manage or treat runoff. Describe any storm water pollution prevention plans. This Project will have no impact on surface water runoff quantity or quality. b. Identify routes and receiving water bodies for runoff from the site; include major downstream water bodies as well as the immediate receiving waters. Estimate impact runoff on the quality of receiving waters. There would be no change in runoff from the site as a result of the proposed Project. 18. Water Quality Wastewater. a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewater produced or treated at the site. Not applicable to the proposed Project. b. Describe waste treatment methods or pollution prevention efforts and give estimates of composition after treatment. Identify receiving waters, including major downstream water bodies, and estimate the discharge impact on the quality of receiving waters. If the project involves on-site sewage systems, discuss the suitability of site conditions for such systems. Not applicable. c. If wastes will be discharged into a publicly owned treatment facility, identify the facility, describe any pretreatment provisions and discuss the facility s ability to handle the volume and composition of wastes, identifying any improvements necessary. Not applicable. d. If the project requires disposal of liquid animal manure, describe disposal technique and location and discuss capacity to handle the volume and composition of manure. Identify any improvements necessary. Describe any required setbacks for land disposal systems. Not applicable. 19. Geologic hazards and soil conditions. a. Approximate depth (in feet) to Ground water: 5 minimum; ~ 50 average. Bedrock: 135 minimum; ~ 200 average. Describe any of the following geologic site hazards to ground water and also identify them on the site map: sinkholes, shallow limestone formations or karst conditions. Describe measures to avoid or minimize environmental problems due to any of these hazards. There are no sinkholes, shallow limestone features, or karst conditions known to exist in the area of the proposed Project. There is no potential for ground water contamination at the site from the proposed Project since construction of the fourth ICE Generator would be contained entirely within the existing LFG-to-Energy building. 7

9 b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity and potential for groundwater contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. All construction work would take place within the existing LFG-to-Energy building. Therefore, no soils would be impacted. 20. Solid Wastes, Hazardous Wastes, Storage Tanks. a. Describe types, amounts and compositions of solid or hazardous wastes, including solid animal manure, sludge and ash, produced during construction and operation. Identify method and location of disposal. For projects generating municipal solid waste, indicate if there is a source separation plan; describe how the project will be modified for recycling. If hazardous waste is generated, indicate if there is a hazardous waste minimization plan and routine hazardous waste reduction assessments. Very small quantities of waste material, such as packing material, and miscellaneous scrap piping and electrical wiring would result due to construction associated with the new ICE generator set. The few wastes that will be generated by the continued operation of the ICE generator sets will include that from the small number of on-site workers, and from maintenance and repair of on-site equipment. Equipment maintenance will generate small quantities of used oil, lubricants, and cleaning fluids. Used oils, cleaning fluids, and other such wastes generated at the Landfill site are managed by licensed waste haulers. b. Identify any toxic or hazardous materials to be used or present at the site and identify measures to be used to prevent them from contaminating groundwater. If the use of toxic or hazardous materials will lead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize or eliminate the waste, discharge or emission. Several petroleum based products are used by and in the maintenance of the ICE generator sets. Such materials include, but are not limited to oil, used oil, waste oil, petroleum based lubricants, and minor amounts of cleaning solvents. All materials used by the engines and in maintenance of the engines are located within the building and properly contained, therefore eliminating the chances of these materials reaching ground or surface waters. As required by state and federal regulations, the ERL implements a Spill Control and Countermeasure (SPCC) Plan and a Stormwater Pollution Prevention Plan (SWPPP). These plans help the facility manage on-site, toxic or hazardous materials, greatly reducing the potential for waters of the State to be adversely affected. These plans are required to be regularly reviewed and evaluated to ensure proper implementation of the plans. c. Indicate the number, location, size and use of any above or below ground tanks to store petroleum products or other materials, except water. Describe any emergency response containment plans. No new underground tanks will be installed as a result of this Project. No tanks are located in the LFG-to-energy plant. Several 55-gallon drums of oil, and pint-to-five-gallon-sized containers of oils and other petroleum based lubricants are located within the plant. The ERL has an Emergency Response Plan and a Contingency Action Plan in addition to the SPCC Plan and SWPPP discussed in Section 20.b. above. These plans include actions to be taken in response to a spill at the facility. 8

10 21. Traffic. Parking spaces added: 0 Existing spaces (if project involves expansion): 0 Estimated total average daily traffic generated: (same as existing) Estimated maximum peak hour traffic generated (if known) and its timing: NA Provide an estimate of the impact on traffic congestion affected roads and describe any traffic improvements necessary. If the project is within the Twin Cities metropolitan area, discuss its impact on the regional transportation system. No additional traffic is anticipated to be associated with the Project. Sufficient parking is currently available at the existing Landfill for employees and visitors. 22. Vehicle-related Air Emissions. Estimate the effect of the project s traffic generation on air quality, including carbon monoxide levels. Discuss the effect of traffic improvements or other mitigation measures on air quality impacts. Note: If the project involves 500 or more parking spaces, consult EAW Guidelines about whether a detailed air quality analysis is needed. Upon completion of construction, the Project is not anticipated to have any effect on vehicle-related air emissions. Vehicle traffic during construction would consist of equipment deliveries and contractors traveling to and from the work site. 23. Stationary Source Air Emissions. Describe the type, sources, quantities and compositions of any emissions from stationary sources of air emissions such as boilers, exhaust stacks or fugitive dust sources. Include any hazardous air pollutants (consult EAW Guidelines for a listing), any greenhouse gases (such as carbon dioxide, methane, and nitrous oxides), and ozone-depleting chemicals (chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons or sulfur hexafluoride). Also describe any proposed pollution prevention techniques and proposed air pollution control devices. Describe the impacts on air quality. As stated in Section 6.b., the increase in air emissions represents the most significant impact associated with this Project. The Project consists of four Caterpillar Model 3516 engine generator sets that use landfill gas as fuel to generate electricity. Air Emissions from the Existing Facility Combined emission sources for the ERL include fugitive landfill gas emissions, secondary combustion emissions from the ICEs and flare, and fugitive dust. Landfill gas is produced as refuse decomposes in a landfill. Typical landfill gas is composed of approximately 50 percent methane and 50 percent carbon dioxide along with trace compounds known as non-methane organic compounds (NMOCs). Methane and carbon dioxide are colorless and odorless, and are considered greenhouse gases. NMOCs are organic compounds (i.e. compounds that contain carbon) that may occur naturally or be formed by synthetic chemical processes. Examples of NMOCs are trichloroethylene, benzene, and vinyl chloride. The facility s air emissions are regulated under ERL's current Title V Air Permit that was issued on March 29, Under the U.S. Protection Agency s (USEPA) New Source Performance Standards (NSPS), ERL is required to operate an active gas collection and control system (see Section 6.b.). Fugitive landfill gas emissions are controlled at ERL through the installation of a landfill gas collection and control system. The landfill gas control system consists of the use of the ICE generator sets and an enclosed flare. The landfill gas that is used as fuel for the ICE generator sets has been treated as defined for the purposes of the NSPS. The maximum landfill gas generation rate for the existing Landfill is projected at 4,045 cubic feet per 9

11 minute (cfm). This generation rate is expected to occur shortly after closure of the landfill. With the addition of the proposed SDA, which is the subject of a separate and ongoing EIS, the maximum landfill gas generation rate may exceed 5,225 cfm, shortly after closure. The gas generation rates are taken into consideration in designing the gas management system for the Landfill. The current active gas extraction system consists of 40 extraction wells operating continuously to extract the landfill gas for destruction using the ICE generators, or through the enclosed flare. The NSPS regulations require monitoring of surface emissions to ensure the proper operation of the collection system equipment. Federal rules require operation of the gas collection system such that the methane concentration of the surface is less than 500 parts per million above background levels. USEPA s AP-42 compendium of emission factors estimates overall collection efficiency ranges from 60% to 85%. Monitoring of potential landfill gas migration off-site of the Landfill is currently being completed using a network of fifteen gas-monitoring probes. These probes have consistently shown a methane concentration of zero percent. Currently, the three ICEs at the LFG-to-energy plant operate at approximately cfm each, for a total of cfm. The actual cfm the engines are able to combust varies with the quality of gas delivered to the plant. The existing enclosed flare at the facility has the capacity to combust 2,000 cfm of landfill gas but the current Title V Air Permit pre-authorizes a modification to increase the flare s capacity to 3,000 cfm. Air Emissions from the ICE Generator Sets The fourth ICE generator set (which is the only one of the four ICE generator sets to be installed after 12/19/02) is also subject to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Reciprocating Internal Combustion Engines. Secondary combustion emissions are generated when landfill gas is combusted in the engines and flare. Carbon monoxide and organic compounds can be emitted as a result of incomplete combustion. Nitrogen oxides are formed during any combustion process when nitrogen from both the landfill gas and excess air needed for landfill gas control reacts with the oxygen at high temperatures. Sulfur dioxides are formed when sulfur contained in landfill gas reacts with oxygen at high temperatures. The flare destruction efficiency of landfill gas is 98% and the ICEs destruction efficiency various significantly depending on the chemical species. Typically, the ICE generator sets are operating at maximum capacity and the flare is used alone when the engines are shut down for maintenance. The following table provides an estimate of the potential air emissions from the four ICE generator sets: Potential to Emit (PTE) in Tons Per Year Pollutant PM PM10 SO2 NOx VOC CO HAPs PTE four ICE generator sets PM = Particulate Matter SO2 = Sulfur Dioxide VOCs = Volatile Organic Compounds HAPs = Hazardous Air Pollutants PM10 = PM smaller than 10 microns NOx = Nitrogen Oxides CO = Carbon Monoxide Air Dispersion Modeling and Air Risk Analysis 10

12 USEPA and the State of Minnesota have established National and Minnesota Ambient Air Quality Standards (NAAQS and MAAQS, respectively) that are designed to be protective of public health and the environment and are not to be exceeded. As part of the air quality permit application, an air dispersion modeling assessment has been completed to determine compliance with NAAQS and MAAQS. Air dispersion modeling is the primary predictive tool used by regulatory agencies for evaluating air impacts. Air dispersion modeling uses comprehensive facility information (emission rates, stack height, stack diameter, and stack gas temperature and velocity) coupled with representative meteorological data (such as temperature, wind direction, and wind speed) to predict ambient air concentrations at and beyond the facility boundary. MPCA has developed the Air Emissions Risk Analysis (AERA) process to evaluate air emissions from facilities that emit more than 100 tons per year of a criteria pollutant for the potential to pose unacceptable risks to the public. The criteria pollutant that triggered the AERA process for this Project was carbon monoxide (CO). The MPCA generally uses the term risk to refer to estimated cancer risks and potential noncancer health effects. The air dispersion modeling showed that no criteria pollutant ambient air quality standards would be violated at the Landfill from the Project. Fully refined air dispersion modeling was needed to demonstrate that the particulate matter less than 10 micrometers in diameter (PM10) emissions would meet the 24-hour ambient standards. PM10 comes from the fugitive dust emissions (dozers and truck traffic), the ICE generators, and the flare. A screening method was used to determine the air emissions of the air pollutants of concern using emission factors from EPA, the internal combustion engine manufacturer, and the California Air Toxic Emission Factor database. Refined dispersion modeling was then performed to estimate the maximum air concentrations of these pollutants. The results of the analysis showed cancer and noncancer risks to be slightly above thresholds, however, due to the conservative nature of the analysis, the Project is not expected to pose unacceptable health risks to the public. 24. Odors, noise and dust. Will the project generate odors, noise or dust during construction or during operation? Yes No If yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures to mitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts on them. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated by operations may be discussed at item 23 instead of here.) The ICE generator sets are contained within a closed building thus mitigating odors, noise, and dust during construction and operation. In response to odors noted in the area of the LFG-to-energy plant, the ERL and ERMU did a series of odor testing of major point sources in the vicinity of the gas plant. The odor sampling conducted included both odor panel testing (subjective) and analytical laboratory testing (objective). Results from the testing indicated elevated odor levels from the engine exhaust and the engine s crank case breather vent. Since a large portion of the odors in the area were coming from the crank case breather vent, the ERL and ERMU have committed to purchasing a control device, nicknamed the Smog Hog, which will be installed on the crank case breather vent. This control device is expected to significantly reduce the emissions and odors from this source. Installation of the fourth ICE generator set will include emissions similar to the existing three engines. The emissions from the fourth engine s crank case breather vent will also be routed through the Smog Hog. Therefore, no notable increase in odors from this emissions source is expected due to the installation of the fourth engine. 25. Nearby resources. Are any of the following resources on or in proximity to the site? 11

13 a. Archaeological, historical, or architectural resources? Yes No b. Prime or unique farmlands or land within an agricultural preserve? Yes No c. Designated parks, recreation areas, or trails? Yes No d. Scenic views and vistas? Yes No e. Other unique resources? Yes No If yes, describe the resource and identify any project-related impacts on the resources. Describe any measures to minimize or avoid adverse impacts. No impacts to archeological, historical, or architectural resources would occur as a result of this Project. Installation of the fourth ICE generator set would take place within the footprint of the LFG-to-Energy plant located on-site of the existing Landfill. There is a designated trail located along the abandoned Burlington Northern Railroad Bed, along the western edge of the Landfill property. The southern end of the Rice Lake wetland complex is located to the west of the walking trail. The existing trees along the western edge of the Landfill provide a natural visual buffer. End uses for the closed Landfill site will be coordinated with Sherburne County and the City of Elk River. The plan for end use of the Landfill site includes recreational trails that complement the existing trail and wildlife viewing areas that overlook the Rice Lake wetland complex. The LFG-to-energy plant will continue operating upon closure of the Landfill until landfill gas generation rates are such that continued operation of the plant is no longer feasible. During the post-closure period, it is likely that the gas-to-energy plant will operate until gas generation rates fall below 1,000 cfm. Since the LFG-to-Energy plant is located on the east side of the Landfill property, the Project is not expected to adversely impact the designated trail, the Rice Lake/Tibbits Brook wetland complex, or potential recreational end uses of the Landfill property. 26. Visual impacts. Will the project create adverse visual impacts during construction or operation? Such as glare from intense lights, lights visible in wilderness areas and large visible plumes from cooling towers or exhaust stacks? Yes No If yes, explain. After construction there would be an addition of a 26-foot stack to the three 26-foot stacks already present for the existing ICE generator sets and the stack of the existing flare which is 36 feet in height. Due to the presence of the existing three engine stacks and the existing flare, the addition of the fourth stack is not anticipated to create an adverse visual impact. 27. Compatibility with plans and land use regulations. Is the project subject to an adopted local comprehensive plan, land use plan or regulation, or other applicable land use, water, or resource management plan of a local, regional, state or federal agency? Yes No If yes, describe the plan, discuss its compatibility with the project and explain how any conflicts will be resolved. If no, explain. The proposed Project is within the existing LFG-to-Energy Plant building which is located on-site of the existing Landfill and within the city limits of Elk River. The proposed Project is not expected to be incompatible with the local land use plan, City and Sherburne County ordinances, and the City comprehensive plan. 28. Impact on infrastructure and public services. Will new or expanded utilities, roads, other infrastructure 12

14 or public services be required to serve the project? Yes No If yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is a connected action with respect to the project must be assessed in the EAW; see EAW Guidelines for details.) 29. Cumulative impacts. Minn. R , subp. 7, item B requires that the RGU consider the cumulative potential effects of related or anticipated future projects when determining the need for an environmental impact statement. Identify any past, present or reasonably foreseeable future projects that may interact with the project described in this EAW in such a way as to cause cumulative impacts. Describe the nature of the cumulative impacts and summarize any other available information relevant to determining whether there is potential for significant environmental effects due to cumulative impacts (or discuss each cumulative impact under appropriate item(s) elsewhere on this form). Currently, the three ICE generator sets operate at approximately cfm each to a total of 900-1,050 cfm. The existing enclosed flare has the capacity to combust 2,000 cfm of landfill gas but the current Title V Air Permit pre-authorizes a modification to increase the flare s capacity to 3,000 cfm. With the addition of the fourth engine, the combined capacity of the combustion equipment can reach approximately 4,400 cfm. ERL does not anticipate a need to increase the capacity of the flare for at least two years and most likely, not for another five years. It should be noted, however, that the air dispersion modeling and AERA performed for this project assumed the flare operating at its maximum future design capacity of 3,000 cfm. The air dispersion modeling and AERA also conservatively included potential emissions projected for the SDA expansion. If the Landfill expands into the SDA area, ERL may need to expand the current gas control facilities at some point before the Landfill closes. Other possible reasons for an increase in landfill gas generation include higher than expected MSW acceptance rates and the recirculation of leachate (conducted as a pilot study at ERL). The air dispersion modeling indicated that: (1) the facility came closest to exceeding the 24-hour PM10 AAQS, (2) the maximum 24-hour PM10 concentration occurred on the eastern side of the property line approximately 450 meters south of the LFG-to-energy plant, and (3) the most culpable sources for this concentration were unpaved roads and bulldozer operations. This analysis implies that the installation of additional ICE generator sets and/or a second flare will not significantly change the maximum modeled 24-hour PM10 concentration because the existing ICE generator sets and flare are not the sources driving the maximum modeled concentration. With the inclusion of potential emissions projected for the SDA in the modeling conducted, including unpaved roads or bulldozer operations associated with the SDA expansion, the ERL has no planned changes in operations of the facility that would impact PM10 concentrations. 30. Other Potential Impacts. If the project may cause any adverse environmental impacts not addressed by items 1 to 28, identify and discuss them here, along with any proposed mitigation. None identified. 31. Summary of issues. List any impacts and issues identified above that may require further investigation before the project is begun. Discuss any alternatives or mitigative measures that have been or may be considered for these impacts and issues, including those that have been or may be ordered as permit conditions. None identified. 13

15 RGU CERTIFICATION. I hereby certify that: The information contained in this document is accurate and complete to the best of my knowledge. The EAW describes the complete project; there are no other projects, stages or components other than those described in this document, which are related to the project as connected actions or phased actions, as defined at Minn. R , subps. 9b and 60, respectively. Copies of this EAW are being sent to the entire EQB distribution list. Name and Title of Signer: Richard Newquist, Supervisor Planning, Review and Operations Unit Date: The format of the was prepared by the staff of the Quality Board at Minnesota Planning. For additional information, worksheets or for EAW Guidelines, contact: Quality Board, 658 Cedar St., St. Paul, MN 55155, , or at their Web site 14