Notice of Availability of an Environmental Assessment Worksheet (EAW) The University of Minnesota, Twin Cities Combined Heat and Power (CHP) Project

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1 Notice of Availability of an Environmental Assessment Worksheet (EAW) The University of Minnesota, Twin Cities Combined Heat and Power (CHP) Project Doc Type: Public Notice Public Comment Information EAW Public comment period begins: October 27, 2014 EAW Public comment period ends: 4:30 p.m. on November 26, 2014 Notice published in the EQB Monitor: October 27, 2014 Permit public comment period begins sometime during the week of October 27 th or November 3 rd. Permit public comment period ends 30 days after comment period begins. Facility Specific Information Facility name and location: Old Main Steam Plant 1180 Main Street SE Minneapolis, MN SW ¼, SE ¼, Section 24, T29N, R24W Minneapolis Township Hennepin County, MN Facility contact: University of Minnesota, Twin Cities Roger Wegner Project Manager th Avenue SE Minneapolis, MN Phone: Fax: wegner002@umn.edu MPCA Contact Information MPCA EAW contact person: Kim Grosenheider Resource Management and Assistance Division Minnesota Pollution Control Agency 520 Lafayette Road North St. Paul, MN Phone: Fax: kim.grosenheider@state.mn.us Admin staff phone: MPCA Permit contact person: Bruce Braaten Industrial Division Minnesota Pollution Control Agency 18 Wood Lake Drive SE Rochester, MN Phone: Fax: bruce.braaten@state.mn.us General Information The Minnesota Pollution Control Agency (MPCA) is distributing this Environmental Assessment Worksheet (EAW) for a 30-day review and comment period pursuant to the Environmental Quality Board (EQB) rules. The MPCA uses the EAW and any comments received to evaluate the potential for significant environmental effects from the project and decide on the need for an Environmental Impact Statement (EIS). An electronic version of the EAW is available on the MPCA Environmental Review webpage at If you would like a copy of the EAW or air emissions permit or have any questions on the EAW or air emissions permit, contact the appropriate person(s) listed above. p-ear2-61a TTY or Available in alternative formats i-admin /2/14 Page 1 of 2

2 Description of Proposed Project The University of Minnesota intends to construct a new combined heat and power (CHP) facility at the existing Main Plant, located on the west side of the Minneapolis campus. The Main CHP Project will consist of a 22.8 megawatt (MW) combustion turbine generator and 270,000 lb/hr of steam capacity. Natural gas will be the primary fuel used to operate the system. Two existing coalfired boilers located at the nearby Southeast Plant will be retired upon commencement of commercial operation of the CHP system. An air emissions permit was prepared and will be posted for public notice during the week of October 27 th or November 3 rd. To Submit Written Comments on the EAW and Air Emissions Permit Written comments on the EAW must be received by the MPCA EAW contact person within the comment period listed above. For information on how to comment on the Air Emissions Permit, contact the MPCA Permit contact person listed above. NOTE: All comment letters are public documents and will be part of the official public record for this project. Need for an EIS (1) A final decision on the need for an EIS will be made after the end of the comment period. (2) If a request for an EIS is received during the comment period, or if the MPCA Commissioner (Commissioner) recommends the preparation of an EIS, the MPCA Citizens Board (Board) will make the final decision. (3) If a request for an EIS is not received, the final decision will be made by the 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. Information on the Board is available at: TTY or Available in alternative formats i-admin /2/14 Page 2 of 2

3 ENVIRONMENTAL ASSESSMENT WORKSHEET Note to reviewers: Comments must be submitted to the MPCA during the 30-day comment period following notice of the EAW in the EQB Monitor. Comments should address the accuracy and completeness of information, potential impacts that warrant further investigation and the need for an EIS. 1. Project Title: The University of Minnesota, Twin Cities Combined Heat and Power (CHP) Project 2. Proposer: Regents of the University of Minnesota 3. RGU: Minnesota Pollution Control Agency Contact person: Roger Wegner Contact person: Kim Grosenheider Title: Project Manager Title: EAW Project Manager Address: 300 Donhowe Building Address: 520 Lafayette Road North th Avenue SE City, State, ZIP: St. Paul, MN City, State, ZIP: Minneapolis, MN Phone: Phone: Fax: Fax: Reason for EAW Preparation: (check one) Required: o EIS Scoping X Mandatory EAW Discretionary: o Citizen Petition orgu Discretion o Proposer Initiated Minn. R subp. 15(B) Air Pollution (Greenhouse Gases) 5. Project Location: County: Hennepin City/Township: Minneapolis PLS Location (¼, ¼, Section, Township, Range): SW ¼, SE ¼, Section 24, Township 29N, Range 24W Watershed (81 major watershed scale): Twin Cities (#20) GPS Coordinates: N: , W: ; (NAD_1983_UTM_Zone_15N) Tax Parcel Number: Attached to the EAW: Figure 1. Hennepin County Map of the Project General Location Figure 2. U.S. Geological Survey Map Figure 3. Site Plan Figure year Flood Map Figure 5. Current and Proposed Site Images Figure 6. Draft Stormwater Plan Map Minneapolis, Minnesota 1 Worksheet

4 Appendix A. State Historic Preservation Officer (SHPO) Letter (1 of 2) Appendix B. State Historic Preservation Officer (SHPO) Letter (2 of 2) Appendix C. Natural Heritage Review Minnesota DNR Letter 6. Project Description: a. Provide the brief project summary to be published in the EQB Monitor, (approximately 50 words). The University of Minnesota intends to construct a new combined heat and power (CHP) facility at the existing Main Plant, located on the west side of the Minneapolis campus. The Main CHP Project will consist of a 22.8 megawatt (MW) combustion turbine generator and 270,000 lb/hr of steam capacity. Natural gas will be the primary fuel used to operate the system. Two existing coal-fired boilers located at the nearby Southeast Plant will be retired upon commencement of commercial operation of the CHP system. b. Give a complete description of the proposed project and related new construction, including infrastructure needs. If the project is an expansion include a description of the existing facility. Emphasize: 1) construction, operation methods and features that will cause physical manipulation of the environment or will produce wastes, 2) modifications to existing equipment or industrial processes, 3) significant demolition, removal or remodeling of existing structures, and 4) timing and duration of construction activities. Overview: The University of Minnesota intends to construct a new CHP facility. The emission units will be installed in the existing Main Plant Building located on the west side of the Minneapolis campus. Originally constructed in 1912, the Main Plant provided steam to the campus until completion of the Southeast Plant Renovation Project in The plant will now be rehabilitated as a modern, energy-efficient facility. The Main CHP Project source emission and air pollution control units will consist of the following equipment: A 22.8 MW combustion turbine generator (CTG, gross power output) A 210 MMbtu/hr duct burner system A 270,000 lb steam/hr heat recovery steam generator (HRSG) A selective catalytic reduction (SCR) system to control nitrogen oxides An oxidation catalyst to control carbon monoxide emissions Natural gas will be the primary fuel used to operate the CHP system. Ultra low-sulfur distillate fuel (ULSD) will be used during periods of natural gas curtailment. ULSD contains no more than 15 parts per million (ppm) sulfur, which will minimize both sulfur dioxide and particulate emissions from the units. In addition, Southeast Boilers 3 and 4 (EU004 and EU005) will be retired upon commencement of commercial operation of the CHP system. These coal-fired boilers are more than 60 years old and no longer meet the University s reliability requirements or sustainability goals. The University of Minnesota will continue operating the remaining three boilers at the Southeast Plant. Minneapolis, Minnesota 2 Worksheet

5 Construction Methods: The University will use the existing Main Building to house the CHP system. The building interior will be demolished and bracing will be used to maintain structural integrity while new superstructure and equipment is put in place. The building shell will be retained but a new roof will be installed. The new facility will therefore have the same footprint as currently exists at the site. Equipment and construction materials will be delivered to the site by truck, using access roads from the west and north. Construction specifications require a solid waste management plan for all waste materials, including demolition debris. University policy requires waste minimization/pollution prevention as well as the recycling of all materials that have an existing market. It is expected that some asbestos and/or mercury or lead-containing materials may be discovered during demolition. All identified special or hazardous materials will be removed and disposed according to University specifications and in compliance with applicable state and federal rules. Stormwater occurring during construction will be managed in accordance with the National Pollution Discharge Elimination System (NPDES)/ State Disposal System (SDS) General Construction Stormwater Permit. A Stormwater Pollution Prevention Plan (SWPPP) will also be prepared prior to construction. Stormwater sediment will be controlled by temporary silt fences, storm sewer inlet protection and other Best Management Practices and techniques. Construction is expected to begin once permits are approved and is expected to be completed by May Operation Methods: The Main CHP system will supply steam and electricity to the Minneapolis campus. Natural gas will be delivered to the facility via pipeline, compressed at the facility, and delivered to the combustion turbine generator and in-exhaust duct burner. Ultra-low sulfur distillate oil will be the auxiliary fuel. Trucks will deliver the fuel to existing storage tanks located northwest of the Main Plant. Natural gas curtailments typically occur 7-12 days per year. Worst-case ULSD consumption is 70,000 gallons per day. Available storage capacity is 730,000 gallons. The number of trucks delivering ULSD should not significantly increase over what is currently required to meet curtailment episodes at the Southeast Plant. Shaft power from the turbine will be used to generate electricity. Exhaust gases will pass by a heat recovery steam generator (boiler), producing steam for distribution to campus buildings. The duct burner will provide additional heat directly to the exhaust gas when steam demand exceeds the capacity of the gas turbine. Once on-line, the Main CHP system will become the primary, or base load, steam production unit for the Minneapolis campus. Existing Southeast Plant boilers will operate when the CHP system is not available, when steam demand exceeds Main Plant capacity, and/or when steam demand is very low. See Table 1 for the 2012 steam demand frequency. Minneapolis, Minnesota 3 Worksheet

6 Steam demand fluctuates by season because nearly all of the steam is used for space heat. The CTG will be able to run at full capacity for all but 500 to 600 hours per year. The duct burner will provide supplemental steam for a majority of the year. Additional steam production will be required by the Southeast Plant between 10 to 15% of annual operating hours (see Table 1). Table Annual Steam Demand Frequency 0-80, Steam Demand < 100% CTG Steam Demand (lb/hr) 80, , , ,000 1,900 Steam Demand near 100% CTG Load, Unfired Steam Demand > 100% CTG Load, Partial Duct Burner Firing 5, , Steam Demand > 100% CTG Load, Full Duct Burner - 1,000 2,000 3,000 4,000 5,000 6,000 Hours per year The Main Plant will emit air pollutants commonly associated with combustion. Air pollution control techniques will be used to limit their quantity and impact: 1) A SCR will be used to control nitrogen oxides. 2) A catalytic oxidation system will be used to control carbon monoxide, volatile organic compounds and organic hydrocarbon-based hazardous air pollutants. 3) Clean fuels (natural gas and ultra-low sulfur distillate oil) will be used to control sulfur dioxide and particulate matter. The SCR system utilizes ammonia in the presence of a catalyst to convert nitrogen oxides to atmospheric nitrogen and water vapor. A small amount of ammonia will remain in the exhaust gas when discharged through the 127-foot stack (less than 5 ppm). Nineteen percent aqueous ammonia will be stored in a 10,000 gallon tank, adjacent to the plant. Catalysts from both the SCR and the oxidation system need to be regenerated or replaced after approximately 50,000 operating hours. Spent catalyst will be properly disposed or recycled in accordance with applicable state rules, requirements, etc. Minneapolis, Minnesota 4 Worksheet

7 The Main Plant will not exceed Significant Emission Thresholds under federal New Source Review (NSR) rules for any pollutant. The University will implement inherently low-emitting design and operating practices to minimize greenhouse gas emissions. Regionally, greenhouse gases will be reduced due to process efficiency and reduced electricity purchases from the local utility. Southeast boilers 3 and 4 will be retired once the Main CHP Plant reaches commercial operation. Worst-case hourly emission rates will be reduced, since Boilers 3 and 4 burn coal without nitrogen oxide or carbon monoxide controls. Wastewater will be generated from continuous blow down from the heat recovery steam generator and reverse osmosis water treatment. In addition, combustion turbine wash water will be generated each week. Additional wastewater may be produced during upset conditions. An industrial discharge permit will be obtained from Metropolitan Council Environmental Services (MCES), allowing wastewater to be discharged to the municipal sewer system and treated at the St. Paul MCES plant (or POTW). Wastewater generated from the water treatment filter backwash process will be discharged into the storm sewer. Stormwater runoff will be discharged into the existing storm sewer infrastructure network. St. Anthony Falls Laboratory (SAFL) baffles will be installed within the two existing sump manholes to enhance sediment removal from storm water runoff prior to discharge into the Mississippi River. c. Project magnitude: Total Project Acreage 1 acre Linear project length 230 feet Number and type of residential units 0 Commercial building area (in square feet) 0 Industrial building area (in square feet) 39,608 square feet Institutional building area (in square feet) 0 Other uses specify (in square feet) 0 Structure heights Building Height - 58 feet Stack Height feet d. 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. Additional steam capacity is necessary to provide reliable service to the Minneapolis campus: The University is at risk for inadequate peak steam capacity beginning in 2014 (firm demand, largest boiler out of service). The University has been relying on aging boiler equipment to meet steam demand (Southeast Boilers 3 and 4 will be retired as part of this project). The University has been relying on a single heating plant with a single steam line that crosses underneath Interstate 35W and the 10th Avenue Bridge. The Main CHP system has been selected because the project: Minneapolis, Minnesota 5 Worksheet

8 Will reduce regional greenhouse gas emissions resulting from the production of steam and electricity consumed on campus. Will reduce the risk to the campus of a primary steam line failure from the Southeast Plant. Will effectively reuse an existing building in accordance with University policy. Conforms to the goals of continuous improvement, energy efficiency and emissions reductions as outlined in the Regents Policy on Sustainability and Energy Efficiency. e. Are future stages of this development including development on any other property planned or likely to happen? Yes x No If yes, briefly describe future stages, relationship to present project, timeline and plans for environmental review. The plant design allocates space for both the installation of a gas/oil fired boiler for steam production and chillers to provide cooling capacity to campus. Neither of these projects is in the active planning phase. Current projections indicate that these systems will likely not be installed before f. Is this project a subsequent stage of an earlier project? Yes x No 7. Cover types: Estimate the acreage of the site with each of the following cover types before and after development: Before After Before After Wetlands 0 0 Lawn/landscaping 0 0 Deep water/streams 0 0 Impervious surface 1 1 Wooded/forest 0 0 Stormwater Pond 0 0 Brush/Grassland 0 0 Other (describe) 0 0 Cropland 0 0 TOTAL Permits and approvals required: List all known local, state and federal permits, approvals, certifications 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. All of these final decisions are prohibited until all appropriate environmental review has been completed. See Minnesota Rules, Chapter Minneapolis, Minnesota 6 Worksheet

9 Unit of Government Type of Application Status FEDERAL: None STATE: Minnesota Pollution Control Agency (MPCA) National Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) Construction Stormwater General Permit To be applied for MPCA Air Permit Amendment Application submitted MPCA NPDES/SDS Industrial Stormwater Permit To be applied for MPCA MPCA Minnesota Department of Natural Resources (MINNDNR) State Historical Preservation Office LOCAL: Metropolitan Council Environmental Services NPDES/SDS Industrial Groundwater Pump Out Permit Municipal Separate Storm Sewer System (MS4) Construction Dewatering Water Appropriation Permit Final Determination of No Adverse Effects Industrial Waste Discharge Permit To be applied for if groundwater pump out is required and contaminant levels exceed permitting thresholds. The project will meet all requirements laid out in the existing University of Minnesota MS4 Program. To be applied for if groundwater pump out is required and the amount of discharge exceeds 10,000 gallons per day. Issued To be applied for University of Minnesota Building Permit To be applied for Other Non-Governmental Unit: None Public Financial Assistance State appropriation/state Bonds $10,000,000 Granted University Bonds $81,398,750 Granted Cumulative potential effects may be considered and addressed in response to individual EAW Item Nos. 9-18, or the RGU can address all cumulative potential effects in response to EAW Item No. 19. If addressing cumulative effect under individual items, make sure to include information requested in EAW Item No Land use: a. Describe: i. Existing land use of the site as well as areas adjacent to and near the site, including parks, trails, prime or unique farmlands. Minneapolis, Minnesota 7 Worksheet

10 The property was used as a heating plant from 1910 until it was replaced by the Southeast Steam Plant in During the interim, the heating plant building has been used as a workshop for the University s steam fitters and it contains access to the operating steam tunnel system. Adjacent land uses include an electrical substation, hydroelectric plant, the Southeast Steam plant and the University campus to the northwest. ii. Plans. Describe planned land use as identified in comprehensive plan (if available) and any other applicable plan for land use, water, or resources management by a local, regional, state, or federal agency. The proposed land use will continue to be classified as industrial for the purpose of producing energy and heat for the University of Minnesota. In addition to steam, the reconstructed Main Steam Plant will also provide electricity for the campus. iii. Zoning, including special districts or overlays such as shoreland, floodplain, wild and scenic rivers, critical area, agricultural preserves, etc. The property is part of the University of Minnesota Campus. In the 2009 Twin Cities Master Plan, the Old Main Steam Plant Building is classified as Adaptive Reuse. Since that time the Regents of the University of Minnesota have decided that the highest reuse of the building is for the CHP Project. b. Discuss the project s compatibility with nearby land uses, zoning, and plans listed in Item 9a above, concentrating on implications for environmental effects. The Mississippi National River and Recreation Area is contained within an urban region. Several industries operate along the shore of the Mississippi River as it flows through Minneapolis, including a metal recycler, hydroelectric power plant, a steam plant, barge terminal, and rail terminal. The proposed project and land use is therefore consistent and compatible with existing industry, land use and zoning. c. Identify measures incorporated into the proposed project to mitigate any potential incompatibility as discussed in Item 9b above. The exterior footprint of the Main Heating Plant, where the proposed CHP project emission and control units will be constructed and operated, will not change. The University will use landscaping and natural vegetation to reduce the plant s visual impact. 10. Geology, soils and topography/land forms: a. Geology - Describe the geology underlying the project area and identify and map any susceptible geologic features such as sinkholes, shallow limestone formations, unconfined/shallow aquifers, or karst conditions. Discuss any limitations of these features for the project and any effects the project could have on these features. Identify any project designs or mitigation measures to address effects to geologic features. The Main Heating Plant Building is located near the base of a bluff and about 60 feet from the bank of the Mississippi River. At this location the Platteville Formation outcrop is visible along the bluff face. The Main Heating Plant was constructed on the St. Peter Sandstone which is the Minneapolis, Minnesota 8 Worksheet

11 upper most bedrock. The depth to the bedrock ranges from 5 feet near the north end of the building and 25 to 33 feet below ground surface on the south end of the building. Groundwater flows to the surface of the Platteville Formation where it outcrops along the bluff. When the Coal Storage Building was constructed, the water flowing from the bluff was directed to a channel and managed as stormwater. Exterior construction will be minimal since the Old Main Steam Plant physical structure will be used to house the CHP equipment. The ammonia tank will be constructed at floor level with secondary containment. The retaining wall on the north side of the building has deteriorated and will be rebuilt as part of the project. b. Soils and topography - Describe the soils on the site, giving NRCS (SCS) classifications and descriptions, including limitations of soils. Describe topography, any special site conditions relating to erosion potential, soil stability or other soils limitations, such as steep slopes, highly permeable soils. Provide estimated volume and acreage of soil excavation and/or grading. Discuss impacts from project activities (distinguish between construction and operational activities) related to soils and topography. Identify measures during and after project construction to address soil limitations including stabilization, soil corrections or other measures. Erosion/sedimentation control related to stormwater runoff should be addressed in response to Item 11.b.ii. On-site soils consist primarily of fill over bedrock. The fill is primarily silty sand with crushed limestone, sandstone, slag, and inert debris. On the north and west sides of the building, the fill depth ranges from 4 to 7 feet thick, and along the south side of the building, it is 29 to 33 feet thick. The upper most bedrock on the north side of the site is the Platteville Limestone, and beneath the building the bedrock is the St. Peter Sandstone. Excavation of soils will be minimal since most of the work will be performed on the interior of the building. A contingency plan will be adopted to manage contaminated soil and to mitigate any releases to the soil. Excavated soil that meets the requirements for unregulated fill will be tested for any contaminants of concern based on historical site uses. Soil will be compared to the appropriate MPCA Soil Reference Values (SRVs) based on the intended use. Soil passing the appropriate SRVs will be either used on site or disposed of as construction debris. Soil exceeding the appropriate SRVs will be disposed of at a Subtitle permitted landfill. 11. Water resources: a. Describe surface water and groundwater features on or near the site in a.i. and a.ii. below. i. Surface water - lakes, streams, wetlands, intermittent channels, and county/judicial ditches. Include any special designations such as public waters, trout stream/lake, wildlife lakes, migratory waterfowl feeding/resting lake, and outstanding resource value water. Include water quality impairments or special designations listed on the current MPCA 303d Impaired Waters List that are within 1 mile of the project. Include DNR Public Waters Inventory number(s), if any. The Mississippi River is 60 feet south of the Main Steam Plant Building. The river in this area is part of the Mississippi National River and Recreation Area and it is a flyway for migrating Minneapolis, Minnesota 9 Worksheet

12 birds. The Minnesota Department of Natural Resources (MDNR) Public Waters Inventory number is 27-3P. The MPCA has classified this reach of the Mississippi River as a Class 2Bd surface water that is protected as a source of drinking water. Class 2Bd waters support cool and warm water fish and associated aquatic life. The river may be used for fishing and water sports. The MPCA has also listed the Mississippi River as impaired water with a total maximum daily load plan for mercury in fish tissue and fecal coliform. ii. Groundwater aquifers, springs, seeps. Include: 1) depth to groundwater; 2) if project is within a MDH wellhead protection area; 3) identification of any onsite and/or nearby wells, including unique numbers and well logs if available. If there are no wells known on site or nearby, explain the methodology used to determine this. The County Well Index, the statewide well database, was searched to identify wells within the project area. No well records were identified on the property or on adjacent properties. There are no domestic wells in the area. Minneapolis and St. Paul have municipal water intakes in Fridley, Minnesota. The site is not in a source water protection area or a wellhead protection area. Groundwater seeps from the Platteville Limestone bluff at the Coal Storage Building. The water is channeled and flows through the lower level of the Main Steam Plant and out to the Mississippi River. Water in the Platteville Formation is at about Elevation 777 feet above mean sea level (MSL). The water table in the St Peter Formation ranges from about Elevation 721 to 731 ft. MSL (groundwater depth ranges from feet), and groundwater flow is to the southwest toward the Mississippi River. The current site is already connected to the city of Minneapolis water supply. It is not anticipated that dewatering will be required for this project, although limited perched water may be encountered. Dewatering during construction is expected to be limited if needed. b. Describe effects from project activities on water resources and measures to minimize or mitigate the effects in Item b.i. through Item b.iv. below. i. Wastewater - For each of the following, describe the sources, quantities and composition of all sanitary, municipal/domestic and industrial wastewater produced or treated at the site. 1) If the wastewater discharge is to a publicly owned treatment facility, identify any pretreatment measures and the ability of the facility to handle the added water and waste loadings, including any effects on, or required expansion of, municipal wastewater infrastructure. Domestic wastewater and industrial wastewaters will be generated at the facility, and discharged into the Metropolitan Disposal System owned and operated by the Metropolitan Council Environmental Services (MCES), the local public owned treatment facility. Industrial wastewater will include those items shown in Table 2. MCES operates a publicly owned system of interceptor sewers and treatment facilities, for the conveyance, treatment and disposal of domestic waste, industrial waste and other waste from residential, commercial, institutional, and industrial Minneapolis, Minnesota 10 Worksheet

13 users in the Metropolitan Area. Wastewater from the facility will be discharged into the Metropolitan Wastewater Treatment Plant. The facility will be required to obtain an Industrial Discharge Permit from MCES once operation starts, and to comply with any standards and requirements set forth in MCES Waste Discharge Rules. The facility s wastewater discharge may also be required to comply with any standards set forth in the Effluent Limitation Guidelines & Standards for the Steam Electric Power Generating Industry, promulgated by the U. S. Environmental Protection Agency (EPA). These proposed guidelines and standards are expected to be finalized by September 15, Description Type Frequency Duration Est. Peak Flow, gpm Continuous blow down tank drain HRSG-1 Intermittent blow down tank drain HRSG-1 Deaerator DA-1 Overflow Condensate tank CT-1 overflow Constituents Continuous N/A N/A 17 Boiler drum water, may contain phosphate and O2 scavenger chemicals Periodic Upset condition Upset condition Once per shift Rare Rare 3 to 4 minutes Until upset condition is resolved (<10 minutes) Until upset condition is resolved (<10 minutes) 100 Boiler drum water, may contain phosphate and O2 scavenger chemicals 380 Deaerated boiler feed water, O2 scavenger 500 Non-deaerated returning condensate Comments Boiler treatment chemicals may be added Not concurrent with future boiler Unlikely occurrence, would require a failure of DA level controls concurrent with a period of very low campus steam demand Unlikely occurrence, would require a failure of either the plant condensate pumps or the Southeast Plant condensate transfer Minneapolis, Minnesota 11 Worksheet

14 RO water treatment reject Process cooling tower blow down CTG-1 water wash drain CTG-1 misc. fuel oil and oily waste drains Periodic 4-6 times per day 1 hour 70 RO reject - basically city water with more highly concentrated hardness and other contaminants; likely some antiscaling chemical as well Continuous N/A N/A 5 Cooling tower water concentrated to 4 cycles (assumed), plus misc. cooling tower chemicals (corrosion inhibitor, scale inhibitor, etc.) Periodic Weekly min 15 RO-quality water mixed with detergent per GE standards Periodic and upset conditions Varies Varies 5 to 10 Lubrication oil, fuel oil, misc. impurities from CTG package pumps during a period of high condensate return Assumes batch runs by the RO system to keep the treated water tank filled Cooling water treatment such as scale inhibitor, algaecide may be added Assumes 4 to 5 wash cycles performed once each week Flow occurs during liquid fuel purge, leakage events, etc. - unpredictable as to volume, duration, and frequency 2) If the wastewater discharge is to a subsurface sewage treatment systems (SSTS), describe the system used, the design flow, and suitability of site conditions for such a system. Not Applicable 3) If the wastewater discharge is to surface water, identify the wastewater treatment methods and identify discharge points and proposed effluent limitations to mitigate impacts. Discuss any effects to surface or groundwater from wastewater discharges. Minneapolis, Minnesota 12 Worksheet

15 Not Applicable ii. Stormwater - Describe the quantity and quality of stormwater runoff at the site prior to and post construction. Include the routes and receiving water bodies for runoff from the site (major downstream water bodies as well as the immediate receiving waters). Discuss any environmental effects from stormwater discharges. Describe stormwater pollution prevention plans including temporary and permanent runoff controls and potential BMP site locations to manage or treat stormwater runoff. Identify specific erosion control, sedimentation control or stabilization measures to address soil limitations during and after project construction. Project construction area is 1.1 acres and will include the re-purpose of an existing building. Other renovations will improve drainage and reduce potential water infiltration into the building. Stormwater runoff from the project site is currently discharged to a storm sewer network prior to discharge to the Mississippi River. The University of Minnesota maintains a Municipal Separate Storm Sewer System (MS4) permit for its Twin Cities Campus. This permit requires the University to implement Best Management Practices (BMPs) as detailed in the campus-specific Stormwater Pollution Prevention Program in addressing stormwater runoff from campus, with the goal of reducing pollutants to the maximum extent practicable. The University will be required to comply with the NPDES/SDS General Permit to discharge stormwater associated with construction activity. An application for coverage under the Minnesota NPDES/SDS Construction Stormwater General Permit will be submitted to the MPCA and a SWPPP will be prepared prior to submittal of the permit application. The SWPPP will include a combination of narrative, plan sheets and standard detail sheets that address the foreseeable conditions, at any stage in the construction activities. It will include a description of the nature of the construction activity and address the potential discharge of sediment and other pollutants from the site. The SWPPP will address both temporary and permanent stormwater treatment and control at the project site. Temporary sediment controls may include silt fences or biorolls, storm sewer inlet protection for all on-site catch basins, and rock construction entrance. In accordance with the Minnesota NPDES/SDS Construction Stormwater General Permit conditions, regular inspection of the site will be made to ensure that erosion and sedimentation controls are working as designed. Permanent sediment control measures for the proposed project include turf establishment and the installation of sump manholes equipped with SAFL baffles to minimize release of solids from stormwater runoff into the Mississippi River. Permanent stormwater management may include rerouting and collecting runoff for reuse in cooling towers. (See Figure 6 for a draft stormwater plan map.) Minneapolis, Minnesota 13 Worksheet

16 iii. Water appropriation - Describe if the project proposes to appropriate surface or groundwater (including dewatering). Describe the source, quantity, duration, use and purpose of the water use and if a DNR water appropriation permit is required. Describe any well abandonment. If connecting to an existing municipal water supply, identify the wells to be used as a water source and any effects on, or required expansion of, municipal water infrastructure. Discuss environmental effects from water appropriation, including an assessment of the water resources available for appropriation. Identify any measures to avoid, minimize, or mitigate environmental effects from the water appropriation. University of Minnesota well records and the County Well Index Statewide Well Database were searched to identify wells within the project area. No well records were identified in the well search. If a well is discovered during the project, the well will be sealed in accordance Minn. R The current site is already connected to the city of Minneapolis water supply. No change in the source of water supply is anticipated. It is not anticipated that dewatering will be required for this project, although limited perched water may be encountered on layers of clay within the fill material. Some seepage of water may also be encountered within the Platteville Limestone or perched water on top of shale. Groundwater will likely be encountered if drilled shafts are constructed for building support. If more than two inches of water are present, a sump pump will be used to lower the water level. The project will apply for a temporary dewatering permit from the MDNR and/or the MPCA for the groundwater discharge, if required. iv. Surface Waters a) Wetlands - Describe any anticipated physical effects or alterations to wetland features such as draining, filling, permanent inundation, dredging and vegetative removal. Discuss direct and indirect environmental effects from physical modification of wetlands, including the anticipated effects that any proposed wetland alterations may have to the host watershed. Identify measures to avoid (e.g., available alternatives that were considered), minimize, or mitigate environmental effects to wetlands. Discuss whether any required compensatory wetland mitigation for unavoidable wetland impacts will occur in the same minor or major watershed, and identify those probable locations. There are no wetlands on the property. b) Other surface waters- Describe any anticipated physical effects or alterations to surface water features (lakes, streams, ponds, intermittent channels, county/judicial ditches) such as draining, filling, permanent inundation, dredging, diking, stream diversion, impoundment, aquatic plant removal and riparian alteration. Discuss direct and indirect environmental effects from physical modification of water features. Identify measures to avoid, minimize, or mitigate environmental effects to surface water features, including in-water Best Management Practices that are proposed to avoid or minimize Minneapolis, Minnesota 14 Worksheet

17 turbidity/sedimentation while physically altering the water features. Discuss how the project will change the number or type of watercraft on any water body, including current and projected watercraft usage. There will be no physical effects or alterations to the Mississippi River, such as draining, filling, permanent inundation, dredging, diking, stream diversion, impoundment, aquatic plant removal, and riparian alteration. The project will not change the number or type of watercraft on the Mississippi River. Although the Mississippi River is about 60 feet from the building, there is expected to be no changes to the water quality or quantity. The University will comply with the Minnesota NPDES/SDS General Stormwater Construction Permit to discharge stormwater associated with construction. A SWPPP will be prepared prior to construction, and will address both temporary and permanent stormwater treatment and control at the project site. Temporary sediment controls will include silt fences or biorolls, storm sewer inlet protection for all on-site catch basins, and rock construction entrance. Regular inspection of the site will be made to ensure that erosion and sediment controls are working as designed. 12. Contamination/Hazardous Materials/Wastes: a. Pre-project site conditions - Describe existing contamination or potential environmental hazards on or in close proximity to the project site such as soil or ground water contamination, abandoned dumps, closed landfills, existing or abandoned storage tanks, and hazardous liquid or gas pipelines. Discuss any potential environmental effects from preproject site conditions that would be caused or exacerbated by project construction and operation. Identify measures to avoid, minimize or mitigate adverse effects from existing contamination or potential environmental hazards. Include development of a Contingency Plan or Response Action Plan. The following is a description of previous environmental releases and studies at or near the proposed site location: MPCA Leak Site ID: LEAK Fourteen 50,000 gallon underground fuel oil storage tanks were removed in 1996, and the petroleum impacted soil was removed and thermally treated off site. The MPCA file was closed on May 15, MPCA Spill and Leak Site IDs: SPILL and LEAK There was also a pipeline release in 1996 into a small courtyard. The fuel oil was excavated to the top of the bedrock, and the MPCA closed the site on January 20, In 1989, a fuel oil release (Leak Site 919) was discovered and the impacted soil was removed. The site was closed later that year. Three fuel oil releases have been investigated and remediated during and following transfer of steam plant operations to the Southeast Steam Plant. MPCA Leak Site ID: LEAK Additional petroleum contamination was discovered and remediated during construction of the Coal Storage Building in 1998 and The file was closed in A passive groundwater collection system was installed to collect Minneapolis, Minnesota 15 Worksheet

18 groundwater and discharge it to the sanitary sewer. After the impacted soil was removed, the groundwater no longer contained petroleum contaminants. The water is currently discharged to the Mississippi River through the stormwater system. b. Project related generation/storage of solid wastes - Describe solid wastes generated/stored during construction and/or operation of the project. Indicate method of disposal. Discuss potential environmental effects from solid waste handling, storage and disposal. Identify measures to avoid, minimize or mitigate adverse effects from the generation/storage of solid waste including source reduction and recycling. Any solid waste generated during construction, including collected sediment, floating debris, paper, plastic, construction and demolition debris, and other wastes, will be collected and properly disposed of in accordance with applicable solid waste rules. Assuming 8 to 10 employees using the site during work hours of operation, solid waste generated during operations is anticipated to range from 2.7 to 3.5 pounds per person or 25 to 35 pounds per day for the facility (source: Environmental Protection Agency). Any solid waste generated during operation will be collected by the University s Waste Management Unit. The University also has an extensive recycling program that includes collection and processing at the University Recycling Center. Recycled materials include paper, cardboard, glass, cans and bottles. c. Project related use/storage of hazardous materials - Describe chemicals/hazardous materials used/stored during construction and/or operation of the project including method of storage. Indicate the number, location and size of any above or below ground tanks to store petroleum or other materials. Discuss potential environmental effects from accidental spill or release of hazardous materials. Identify measures to avoid, minimize or mitigate adverse effects from the use/storage of chemicals/hazardous materials including source reduction and recycling. Include development of a spill prevention plan. Any hazardous materials used during construction including oil, gasoline, and paint will be properly stored, including secondary containment, to prevent spills and leaks. This site is not a major facility and therefore will not need a MPCA aboveground storage permit. Aqueous ammonia (19% solution) will be used as reagent for NOx emissions control. Ammonia will be stored in stainless steel aboveground storage tank equipped with secondary containment system. Aqueous ammonia was selected for both air pollution control effectiveness and relatively low hazard rating. This tank will be designed and operated to meet Minn. Rules 7151 including spill/overfill protection and release detection controls. Ultra-low sulfur distillate oil will be used as backup fuel for the CTG, and it will be stored in the two existing fuel oil aboveground storage tanks located nearby the facility. These tanks are equipped with secondary containment systems to prevent spills or leaks. A new pipeline will deliver ULSD from the existing tanks to the Main Plant CHP system. The pipeline will be subject to state and federal requirements for design, leak detection and operation. The pipeline is Minneapolis, Minnesota 16 Worksheet

19 appurtenant to a regulated AST and therefore will be designed and operated to meet Minn. Rules 7151 including release prevention and leak detection as applicable. d. Project related generation/storage of hazardous wastes - Describe hazardous wastes generated/stored during construction and/or operation of the project. Indicate method of disposal. Discuss potential environmental effects from hazardous waste handling, storage, and disposal. Identify measures to avoid, minimize or mitigate adverse effects from the generation/storage of hazardous waste including source reduction and recycling. No hazardous wastes will be generated or stored during construction and/or operation of the project. 13. Fish, wildlife, plant communities, and sensitive ecological resources (rare features): a. Describe fish and wildlife resources as well as habitats and vegetation on or in near the site. The project site is fully developed, including buildings, road, and parking lot. Existing trees on site include cottonwood, box elder, ash, and elm. Shrubs include buckthorn and honeysuckle. There will be no direct impact on the existing habitat as the result of this project. Indirect impacts to the Mississippi River will minimized through the implementation of the NPDES/SDS Construction Stormwater permit and NPDES/SDS Industrial Stormwater permit requirements. b. Describe rare features such as state-listed (endangered, threatened or special concern) species, native plant communities, Minnesota County Biological Survey Sites of Biodiversity Significance, and other sensitive ecological resources on or within close proximity to the site. Provide the license agreement number (LA- ) and/or correspondence number (ERDB ) from which the data were obtained and attach the Natural Heritage letter from the DNR. Indicate if any additional habitat or species survey work has been conducted within the site and describe the results. The MDNR Natural Heritage Information Program (NHIP) was contacted to identify potential state and federally listed threatened, endangered, special concern species, and sensitive resources in the project area (see Attachment C). The NHIP identified several occurrences within a one-mile radius of the project site (discussion follows). No occurrences are found within the project site boundary Vertebrate Animal: A nesting area for Falco Peregrinus (Peregrine Falcon - MN status, Special Concern) is located at the I-94 Bridge and Riverside Plaza Apartments. First nesting was at Riverside Plaza in During the period of adult falcons were observed on the I-94 Bridge, and a nest tray was installed on the bridge in In 2011, a single adult bird was in the area over the winter, but no nesting occurred. The nest box at Riverside Plaza was closed in 2010 due to construction. Another nesting area was on top of the Mayo Building located on the East Bank of the University of Minnesota. The nest box was first used in 2011, but the falcons were disturbed by contractor work and left for an apartment building a few blocks away. Minneapolis, Minnesota 17 Worksheet

20 Perimyotis Subflavus (Tricolored Bat MN status, Special Concern, also known as the Eastern Pipistrelle) was observed in 1988 at the Heinrich Brewery Cave, which is located downstream from Washington Avenue bridge, on the west side of the Mississippi River, at the foot of 4th Street South. An extensive system of caves used as cooling cellars for beer was excavated around 1890 by the Heinrich Brewery (also known as the Minneapolis Brewery). Eight to 10 Eastern Pipistrelles were found utilizing this cave as a hibernaculum and possibly as a dwelling. In 2000, 69 Eastern Pipistrelles were recorded hibernating in Chute s Cave, a limestone and sandstone cave with associated man-made tunnels located near Main Avenue and 5th Street SE. This is the largest number of this species found in any hibernacula in Minnesota. Chute s Cave is the most important hibernaculum for this species in Minnesota. No other bat species were observed. Invertebrate Animal: Several rare mussels, including Elliptio Dilatata (Spike) and Quadrula Nodulata (Wartyback), both Minnesota-listed threatened species, have been documented in the Mississippi River in the vicinity of the project site. Ligumia Recta (Black Sandshell MN status, Special Concern) was also observed in 2000 on the bank of the river. Mussels are particularly vulnerable to deterioration in water quality, especially increased siltation. c. Discuss how the identified fish, wildlife, plant communities, rare features and ecosystems may be affected by the project. Include a discussion on introduction and spread of invasive species from the project construction and operation. Separately discuss effects to known threatened and endangered species. Little impact is expected on fish, wildlife, plant communities, rare features, and ecosystem as the result of this project. d. Identify measures that will be taken to avoid, minimize, or mitigate adverse effects to fish, wildlife, plant communities, and sensitive ecological resources. The project site is currently a fully developed site, including buildings, roads and parking lot. Indirect impacts to the Mississippi River and surrounding area will be minimized through the implementation of various BMPs installed during construction for erosion prevention and sediment control and through various BMPs during operations. 14. Historic properties: Describe any historic structures, archeological sites, and/or traditional cultural properties on or in close proximity to the site. Include: 1) historic designations, 2) known artifact areas, and 3) architectural features. Attach letter received from the State Historic Preservation Office (SHPO). Discuss any anticipated effects to historic properties during project construction and operation. Identify measures that will be taken to avoid, minimize, or mitigate adverse effects to historic properties. The Main Plant Building is not listed on the National Register of Historic Places and therefore is not included in the Minnesota National Register Property Data (administered by Minnesota s State Minneapolis, Minnesota 18 Worksheet

21 Historic Preservation Office - SHPO). The Main Plant Building is also not listed on the Minneapolis Heritage Preservation Commission s list of historic sites. There are no recorded archaeological sites or any known traditional cultural properties in the project area or in close proximity. The SHPO has determined that the project area has a low probability of previously unrecorded archaeological sites (see Attachment A). The Main Plant Building is within the area of potential effect for two adjacent National Register properties, University of Minnesota Old Campus Historic District and the Cedar Avenue Bridge (at 10th Street). The SHPO has determined that the project as designed, will not adversely affect these historic districts (see Attachment B). 15. Visual: Describe any scenic views or vistas on or near the project site. Describe any project related visual effects such as vapor plumes or glare from intense lights. Discuss the potential visual effects from the project. Identify any measures to avoid, minimize, or mitigate visual effects. The only significant external change associated with the project is construction of an exhaust stack. Figure 5 shows a comparison of the project area before and after construction from various perspectives. The stack has been designed to balance visual impact and proper air dispersion. The stack will have a height of 127 feet above grade. The stack height addresses any issues related to plume downwash of stack emissions due to the proximity of the coal enclosure and other University buildings. The proposed stack height is 100 feet shorter than what currently is used at the Southeast Steam Plant. Exterior lighting will be low impact lighting designed to illuminate only the area of concern. 16. Air: a. Stationary source emissions - Describe the type, sources, quantities and compositions of any emissions from stationary sources such as boilers or exhaust stacks. Include any hazardous air pollutants, criteria pollutants, and any greenhouse gases. Discuss effects to air quality including any sensitive receptors, human health or applicable regulatory criteria. Include a discussion of any methods used assess the project s effect on air quality and the results of that assessment. Identify pollution control equipment and other measures that will be taken to avoid, minimize, or mitigate adverse effects from stationary source emissions. Emission Sources: The Main CHP Project will consist of the following emission units and air pollution control equipment: A 22.8 MW combustion turbine generator (CTG, gross power output) A 210 MMbtu/hr duct burner system A 270,000 lb steam/hr HRSG A selective catalytic reduction (SCR) system to control nitrogen oxides An oxidation catalyst to control carbon monoxide emissions Minneapolis, Minnesota 19 Worksheet

22 Natural gas will be the primary fuel combusted, with ULSD oil used during curtailment periods or physical interruption. In addition, Southeast Boilers 3 and 4 will be retired upon commencement of commercial operation of the CHP system. These coal-fired boilers are more than 60 years old and no longer meet the University s reliability requirements or sustainability goals. The University of Minnesota will continue operating the remaining three boilers at the Southeast Plant. The purpose of the Main CHP Plant is to: 1) Provide additional peak steam production capacity during the coldest days of winter. 2) Act as the base load steam plant for the Minneapolis campus. 3) Produce electricity in an economic and reliable manner. Maintaining adequate boiler capacity during peak demand periods is critical to the University. During peak demand, steam production will occur at both the Southeast Plant and the new Main Plant. Steam demand will exceed Main Plant capacity approximately 1,000 hours per year in During the rest of the year, the Main Plant will act as the baseload plant, assuming approximately 80% of annual steam production currently provided by Southeast. Actual emissions from Southeast will decrease in proportion to the reduction in steam production. The Main CHP system will be permitted as an amendment to an existing MPCA Air Emission Permit as described below. Existing Facility Air Emission Permit: The University of Minnesota Twin Cities is an existing air emission facility and is considered a major source under both Title I (New Source Review pre-construction permitting program) and Title V (operating permit program) of the Clean Air Act. The MPCA Air Emission Permit encompasses both the Minneapolis and St. Paul campuses. Each campus has a steam plant, which provides heat (and a small amount of process steam) to campus buildings: The Southeast Steam plant, located immediately east of the Stone Arch Bridge, was most recently renovated in the late 1990s. Total steam production capacity of the Southeast Plant is 722,000 lb steam/hr. Two units produce high pressure steam that can be sent to a steam turbine to cogenerate up to 15,000 kilowatt electricity before sending the steam to campus. The St. Paul plant serves a much smaller campus than the Southeast Plant. Steam is provided primarily from the two newest natural gas-fired boilers. Coal-fired capacity has been used infrequently during the past several years. This plant is unaffected by the current project. Other emission sources on campus include: 102 permitted emergency generators, 42 of which are listed as significant emission units More than 1,000 laboratory fume hoods, which are listed as insignificant activities Approximately 60 small boilers and art kilns, 12 of which are listed as significant emission units Minneapolis, Minnesota 20 Worksheet

23 Existing Facility Unlimited, Allowable and Actual Annual Emissions: Air pollution emissions are presented in three general regulatory categories: Unlimited Potential-to-Emit (PTE), defined as the maximum emissions that can be generated from an emission unit in one year. Unlimited PTE is calculated as if the unit operated 24 hours per day, 365 days per year. Allowable PTE, defined as the annual emissions allowed in the Air Emission Permit, considering pollution control equipment and operating restrictions. Actual Emissions, defined as what is actually emitted for the 12-month MPCA emission inventory period (January through December). Emissions are further separated into the following classes: Criteria Pollutants, which include: Carbon Monoxide (CO) Nitrogen Oxides (NO x ) Particulate Matter (PM) Particulate Matter Less than 10 microns in diameter (PM 10 ) Particulate Matter Less than 2.5 microns in diameter (PM 2.5 ) Sulfuric Acid Mist (SO 3 ) Volatile Organic Compounds (VOC) Greenhouse Gas Pollutants (GHG) Greenhouse Gas Pollutants (GHG), which are the newest criteria pollutant and are regulated somewhat differently from the other listed criteria pollutants. Six regulated pollutants are defined as GHG: Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O) Sulphur hexafluoride (SF 6 ) Hydrofluorcarbons (HFCs) Perfluorocarbons (PFCs) GHG emissions are calculated by multiplying the expected emission rate by the Global Warming Potential of each pollutant. The resulting values, called CO 2 equivalents, are summed to determine GHG emissions. Hazardous Air Pollutants (HAP), which include more than 100 organic and inorganic compounds. The most prominent HAPs created from combustion sources include: Hydrochloric Acid (HCl), which is created from fuel chlorine. HCl is of most concern from coal combustion. Hexane, which is a product of incomplete combustion formed when using natural gas. Formaldehyde, which is a product of incomplete combustion formed when burning ULSD. Minneapolis, Minnesota 21 Worksheet

24 Annual unlimited (PTE) and allowable PTE for the existing facility are presented in Table 2. Allowable emissions are much lower than unlimited PTE because the current permit contains several regulatory limits that apply to the existing steam plants: Annual emissions of criteria pollutants from the Southeast Steam Plant and St. Paul Boiler #8 were restricted to attain Synthetic Minor NSR Modification status for the Southeast Renovation Project, which was permitted in Annual hexane and HCl emissions were restricted to maintain HAP Area Source Status (less than 10 tons per year of an individual HAP). Hexane is formed during natural gas combustion, while HCl is produced from chlorine contained in coal. Annual total HAP emissions from the steam plants were restricted to maintain HAP Area Source Status (less than 25 tons per year total HAPs). The restriction is set at 15 tons per year to accommodate allowable emissions from campus laboratories and emergency generators. In 1997, annual use of coal and ULSD was voluntarily limited to no more than 30% of all fuel combusted at the steam plants. Allowable campus source emissions are much lower due to operating hour restrictions on peakshaving generators. Table 2. Title V Permitted Unlimited and Allowable Emissions Pollutant Unlimited Campus Sources PTE (tons/yr) Unlimited Steam Plants PTE (tons/yr) Unlimited Total PTE (tons/yr) Allowable Campus Sources PTE (tons/yr) Allowable Steam Plants PTE (tons/yr) Allowable Total PTE (tons/yr) Carbon Monoxide 1, , Nitrogen Oxides 4, , , Particulate Matter , , PM , , PM Sulfur Dioxide , , Volatile Organics CO2e 230,212 1,466,701 1,696,913 12, , ,469 Hydrochloric Acid * - Hexane * - TOTAL HAPS * - Table 3 presents actual campus emissions for The Southeast and St. Paul Steam Plants are responsible for more than 90% of actual emissions. Emissions were relatively constant between 2009 and Emissions decreased in 2012, due to the following factors: Minneapolis, Minnesota 22 Worksheet

25 The winter of 2012 was the warmest on record. The temperature reached 5 degrees or lower only 14 days, or half of the 10-year average. The number of heating degree days was 75% of the 100 year-average. There were no natural gas curtailment days in 2012, so ULSD use was not required and coal consumption was historically low. Actual emissions are much lower than allowable emissions for campus sources because emergency generators, which are permitted to operate up to 500 hours per year, are rarely used, except for monthly safety checks and infrequent power outages. Table 3. Historical Annual Air Emissions for the University of Minnesota Twin Cities Pollutant Steam Plants Campus Sources Total Steam Plants Campus Sources Total Steam Plants Campus Sources Total CO Lead NOx PM PM SO VOC CO2e 1 172,629 9, , ,777 9, , ,938 8, ,079 1 Greenhouse gas emissions expressed as carbon dioxide equivalents. Data from EPA Annual GHG Inventory. Main CHP Project Permitting Requirements: Projects that cause an emission increase are required to determine federal NSR Program applicability. The NSR Program contains two subcategories: 1) The Prevention of Significant Deterioration (PSD) Program, which regulates facilities located in areas that are in attainment of national ambient air quality standards (NAAQS); and 2) The Non-Attainment Area Program, which regulates facilities that have not attained one or more of the NAAQS. The Twin Cities Region is in attainment for all criteria pollutants, so the Main CHP Project is regulated under PSD. (For the remainder of this discussion, NSR will generally be used, except when the regulatory element is specifically found under PSD rules.) Under NSR, a permittee must determine if the proposed project will be defined as a Major NSR Modification, subject to further review and regulation. The annual PTE is calculated for the project and compared to NSR Significant Emission Thresholds. The permittee may propose emission limits and/or operating restrictions to reduce maximum annual emissions. These allowable limits must be federally enforceable and contained in the permit amendment. Minneapolis, Minnesota 23 Worksheet

26 Table 4 presents an annual emission summary of the Main CHP Project as included in the MPCA Permit Amendment Application. The project is defined as a Minor NSR Modification for all criteria pollutants. The University has proposed to accept the following operating restrictions that cause the allowable PTE to be less than the respective thresholds: Pollution control equipment will be installed to reduce NOx and CO emissions. Ultra-low sulfur distillate oil (ULSD) will be used, which contains far less sulfur than otherwise allowed (15 ppm versus current limit of 0.3%). ULSD annual consumption will be limited to 2,720,247 gallons, or 10% of maximum annual throughput capacity. The NO x control system operates by selective catalytic reduction. Ammonia is injected into the exhaust gas in the presence of a fixed catalyst. The ammonia reacts with NOx to produce atmospheric (diatomic) nitrogen and water vapor. A small amount of unreacted ammonia is exhausted to the atmosphere as a result of the process (less than 5 ppm). The CO pollution control system is a fixed catalyst that oxidizes CO to CO 2. The system will also convert some VOC to CO 2 and water vapor. Organic HAPs are also controlled, including formaldehyde. Table 4. Main Plant CHP Allowable Emissions and NSR Major Modification Thresholds Pollutant Allowable Annual Emissions (tons per year) Major Modification Thresholds (tons per year) Carbon Monoxide (CO) Nitrogen Oxides (NO 2 ) Particulate Matter (PM) Particulate Matter < 10 microns (PM 10 ) Particulate Matter < 2.5 microns (PM 2.5 ) Sulfur Dioxide (SO 2 ) Sulfuric Acid Mist (H s SO 4 ) Volatile Organic Compounds (VOC) Carbon Dioxide Equivalents (CO 2 e, Greenhouse Gases) 235,092 (a) (a) See GHG discussion in following section. ULSD contains no more than 15 ppm sulfur by weight, which is 400 times less sulfur than allowed under federal rules. ULSD usage will reduce not only SO2 emissions but also particulate matter and sulfuric acid mist: Unreacted ammonia from the SCR system can react with SO2 in the exhaust gas to produce ammonium sulfate, which is a fine particulate. Sulfur can also react with water vapor in the presence of the CO control system to produce sulfuric acid mist. By using ULSD, less sulfur will be available to create either of these pollutants. Minneapolis, Minnesota 24 Worksheet

27 As indicated in Table 4, the project is a Major NSR Modification for GHG, subject to PSD review requirements as discussed below. Main CHP Project PSD Review for GHG: Under federal rules promulgated on May 13,2010, any modification of an existing source with the potential to emit greater than 75,000 tons of GHG is considered to be a Major Modification subject to PSD Review. As indicated in Table 4, the Main CHP Project exceeds the threshold. However, on June 23, 2014 the Supreme Court of the United States decided that the rule does not apply to changes at existing sources that are Minor NSR Modifications for all other criteria pollutants. EPA issued a policy memo on July 24, 2014 confirming that the projects that meet these criteria are not subject to PSD for greenhouse gases. Consequently, the Main CHP Project is not subject to PSD Review for GHG. In any case, the Main CHP project is highly efficient system that will reduce regional GHG emissions (see Question 19). Combined heat and power systems have been recognized by the EPA as an inherently lower-emitting design for GHG pollutants and are considered Best Available Control Technology. The Main CHP project system design uses shaft power from the combustion turbine to generate electricity. Exhaust gas heat passes by a boiler to generate steam for campus use. Total system efficiency will be approximately 80%. In comparison, a utility boiler will use no more than 38% of available energy to produce electricity. Federal New Source Performance Standards (NSPS): The CHP system is subject to the federal NSPS for Stationary Combustion Turbines (40 CFR 60, Subpart KKKK). The NSPS regulates turbine and duct burner emission performance for NOx and SO2. As indicated in Table 5, emission limits proposed by the University to maintain Minor NSR Modification status for criteria pollutants will be more stringent than required by the NSPS. Table 5. Main CHP Voluntary Emission Limits vs. Federal NSPS Control Technique Affected Pollutant s Worst-Case Uncontrolled Emission Rate Proposed Limit / Operating Restriction NSPS Limit 1 Selective Catalytic Reduction (SCR) NO x CTG Only Natural Gas: 25 ppm ULSD: 105 ppm CTG Only Natural Gas: ULSD: CHP System Natural Gas: ULSD: 4 ppm 9 ppm 4 ppm 6 ppm CTG Only Natural Gas: 25 ppm ULSD: 74 ppm HRSG Only All Fuels: 54 ppm Catalytic Oxidation CO CTG Only Natural Gas: 60 ppm ULSD: 25 ppm CHP System 2 Natural Gas: 20 ppm ULSD: 20 ppm NONE Minneapolis, Minnesota 25 Worksheet

28 Fuel Selection (ULSD instead of Distillate Oil) SO 2 CHP System CHP System lb SO 2 /MMBtu lb SO 2 /MMBtu (15 ppm Sulfur) lb SO 2 /MMBtu 1 New Source Performance Standards for Combustion Turbines (40CFR60, Subpart KKKK) 2 Vendor Guarantee. 3 NSPS Limit Hazardous Air Pollutants (HAPs): HAPs emissions are a function of fuel type and combustion method. Table 6 presents HAPS with the highest emission rate for each fuel and total HAP emissions for the facility. Hexane is the primary HAP from natural gas combustion, while formaldehyde is the primary ULSD HAP. The Main CHP Plant will become the base load steam source for the University. Consequently, the Main CHP Plant emissions will take the place of past actual emissions for at least 80% of Southeast Plant operations in a typical year. Table 6. Limited Hourly and Annual HAP Emissions Natural Gas ULSD Limited Hourly Annual Worst-Case Annual Annual EMISSION UNIT POLLUTANT (lb/hr) (tons/yr) (lb/hr) (tons/yr) (tons/yr) Combustion Hexane Turbine (CTG) Formaldehyde TOTAL HAPS Duct Burner Hexane (DB / HRSG) Formaldehyde TOTAL HAPS CHP SYSTEM Hexane Formaldehyde TOTAL HAPS Limited emissions based on a 90/10 natural gas to ULSD annual consumption ratio. All emissions at "Low Ambient" operating conditions, full load operation. Because the CHP system will become the baseload operating system, the University will be able to maintain the current steam plant emission caps for individual and total allowable HAPs listed in Table 1. Minneapolis, Minnesota 26 Worksheet

29 Local Ambient Air Quality Impacts: EPA has established ambient air quality standards for criteria pollutants other than GHG (NAAQS). The standards protect public health and the environment. Compliance is determined through a monitoring network operated by the MPCA. Changes at existing facilities must undertake air dispersion modeling if they are defined as Major NSR Modification for any criteria pollutant other than GHG. Model results are compared to PSD Significant Impact Levels (SILs) for each criteria pollutant. Each SIL is set by EPA at a small fraction of the NAAQS (typically less than five percent of the standard). As a Minor NSR Modification, the University is not required to conduct air dispersion modeling as part of the permitting process. However, the University has conducted screening modeling to ensure that the project will not significantly affect human health or the environment in the community surrounding the facility. Modeling was conducted following an MPCA-approved protocol. The AERSCREEN dispersion model was used. Worst-case hourly emissions (ULSD as fuel, cold-weather operation) and stack temperature (226F) were input to the model, along with actual local geography. Neighboring building dimensions were also input to the model. The modeling run was performed assuming a generic emission rate of one pound per hour. The resulting maximum one-hour ambient air quality concentration was then used as a Unit Impact Multiplier ( ug/m3 air pollution / 1 lb/hr pollutant). The Unit Impact Multiplier was multiplied by each pollutant s worst-case one-hour emission rate to determine each pollutant s maximum ambient air quality impact. MPCA-approved Conversion Factors were also used to convert the one-hour results to estimate longer-term ambient air quality impacts. Results indicate that the proposed plant will not significantly affect local ambient air quality (Table 7). The maximum one-hour ambient air pollutant concentration was located 100 degrees from north and 128 meters from the stack, or at East River Road. Worst-case one hour concentrations are significantly lower at other distances from the facility. Figure 5 presents maximum one-hour Unit Impact Multipliers versus distance from the stack location. Modeling results can be considered environmentally conservative because they do not take into account: 1. The retirement of two coal-fired boilers at the neighboring Southeast Plant. 2. Reduced operation of the remaining Southeast boilers due to baseload operation of the Main CHP Plant. Minneapolis, Minnesota 27 Worksheet

30 Table 7. Air Dispersion Screening Model Summary Results (Worst-Case Operating Conditions) Pollutant Tier 2 Nitrogen Dioxide Modeling Results Averaging Time NO 2 /N O x Ratio Emission Rate (lb/hr) Conversion Factor Unit Impact Multiplier (µg/m 3 ) Max Concentrati on (µg/m 3 ) SIL (µg/m 3 ) Air Quality Standard( µg/m 3 ) NO 2 1-hr Annual *1 ppm NO 2 = 1,880 µg/m 3 Pollutant Averaging Time Emission Rate (lb/hr) Conversion Factor Unit Impact Multiplier (µg/m 3 ) Max Concentrat ion (µg/m 3 ) SIL (µg/m 3 ) Air Quality Standard (µg/m 3 ) CO 1-hr ,000 8-hr ,000 PM hr Annual PM hr Annual SO 2 1-hr hr hr Annual Minneapolis, Minnesota 28 Worksheet

31 AERSCREEN Predicted Worst-Case One-Hour Ambient Air Quality Impacts (Unit Impact Multipliers) Each concentric ring = 200 meters from the Main CHP stack location. Farthest ring is 1,000 meters from the stack location. Each worst-case value below is a discrete point representing the highest one-hour modeled value within the defined radius. All other points within the entirety of each ring at all other hours of the year will have a lower concentration. Distance from Stack (meters) Maximum One-Hour Concentration (ug/m 3 per 1 lb/hr emissions) Distance from Stack (meters) Maximum One-Hour Concentration (ug/m 3 per 1 lb/hr emissions) 100 meters meters meters meters meters meters meters meters meters ,000 meters Minneapolis, Minnesota 29 Worksheet

32 Air Emissions Risk Analysis: The University has utilized air dispersion modeling and allowable emissions to estimate potential individual health risks at the modeled point of worst-case ambient air quality impacts. The Air Emissions Risk Analysis has been developed using the MPCA Risk Assessment Screening Spreadsheet (RASS), a model that quantifies acute and chronic (non-cancer) toxicity and cancer risk for a particular project. RASS is intended as an environmentally conservative screening technique to determine if a more in-depth review of project risk is required. RASS computes risks for each pollutant through multiple pathways, including inhalation and ingestion. Both criteria and HAP emissions are utilized by RASS to calculate the maximum ambient one-hour concentration of each pollutant. These results are combined with benchmark toxicity and cancer risk factors to determine relative health risks for each pollutant. Results are further condensed to develop a cumulative Total Hazard Index and an aggregate cancer risk for the proposed project. The Total Hazard Index is compared against a factor of 1, while cancer risk is compared against a benchmark of 1x10-5, or an increased chance of 1 in 100,000 residents. Table 8 presents the results of the AERA determined by the RASS spreadsheet. As indicated, predicted health impacts from the Main CHP facility are well below MPCA guidelines. Consequently, the new facility will not significantly impact the health of nearby residents. Table 8. Estimated RASS Toxicity Index and Cancer Risk Parameter Urban Gardener Noncancer Risk Urban Gardener Cancer Risk Resident Noncancer Risk Resident Cancer Risk Project Hazard Index 2.E-02 8.E-07 2.E-02 8.E-07 MPCA Guidance Level 1.E+00 1.E-05 1.E+00 1.E-05 Project as % of Guidance 2% 8% 2% 8% Below Guidelines? OK OK OK OK The results as presented are environmentally conservative because the following factors are not considered in the analysis: Results are for the single, worst-case one-hour impact during the year, at one discrete location. Net environmental benefits from reduced operation of the fluidized bed combustor and two natural gas / distillate oil-fired boilers at Southeast. Net environmental benefits from the retirement of Southeast 3 and 4. Minneapolis, Minnesota 30 Worksheet

33 Net Project Emissions: The boilers to be retired, Southeast 3 and 4, have a much higher allowable hourly emissions than the proposed plant (Table 9). While the Southeast boilers are operated infrequently, they are available to provide steam if other boilers are out of service or during times of peak demand. Table 9. Main CHP vs. Southeast 3 & 4 Allowable Hourly Emission Rates COAL COAL COAL CHP NET SE #3 SE #4 SE TOTAL WORST CASE CHANGE POLLUTANT (lb/hr) (lb/hr) (lb/hr) (lb/hr) (lb/hr) CO NOx PM PM PM SO SO VOC As the new baseload plant, the Main CHP system will displace operations at the Southeast plant during most of the year. The remaining three Southeast boilers will be operated primarily when Main is out of service, when peak demand exceeds Main s capacity, and when demand is very low. Consequently, annual emission increases due to operation of the Main Plant will be largely mitigated by the reduction in Southeast operations. b. Vehicle emissions - Describe the effect of the project s traffic generation on air emissions. Discuss the project s vehicle-related emissions effect on air quality. Identify measures (e.g. traffic operational improvements, diesel idling minimization plan) that will be taken to minimize or mitigate vehicle-related emissions. The Main CHP project will not significantly increase vehicle traffic in the area. During construction, there will be an average of 40 to 50 workers on site but most of them will park off site due to a limited number of parking spaces on site. It is estimated that there will be 4 to 5 delivery trucks on site daily during construction. During operation, large trucks will occasionally access the site to fill tanks or drop off consumables such as filters, water treatment chemicals or supplies for steam crew. Automobile traffic will be similar to what is currently seen at the site. Minneapolis, Minnesota 31 Worksheet

34 c. Dust and odors - Describe sources, characteristics, duration, quantities, and intensity of dust and odors generated during project construction and operation. (Fugitive dust may be discussed under item 16a). Discuss the effect of dust and odors in the vicinity of the project including nearby sensitive receptors and quality of life. Identify measures that will be taken to minimize or mitigate the effects of dust and odors. Odors: The proposed facility will not generate odors during construction or operation. Dust: Some dust will be generated during typical hours of construction (6:00 am-4:00 pm). Dust control during construction phase will be in form of water or as specified by the construction engineer. 17. Noise Describe sources, characteristics, duration, quantities, and intensity of noise generated during project construction and operation. Discuss the effect of noise in the vicinity of the project including 1) existing noise levels/sources in the area, 2) nearby sensitive receptors, 3) conformance to state noise standards, and 4) quality of life. Identify measures that will be taken to minimize or mitigate the effects of noise. Noise will occur during construction and ongoing plant operations. Minnesota Noise Standards ( ) are established based on area classification and time of day. For residential areas, noise may not exceed 60 decibels 50% of the time (L50) or 65 decibels 10% of the time (L10). During nighttime hours (10:00 pm to 7:00 am), the L50 standard is 50 dba and the L10 standard is 55 dba. Nearby noise sources include vehicle traffic from Interstate 35W, 10th Avenue, and University Avenue. Additional noise is generated by railroad and river traffic. During construction, noise will be generated from vehicles delivering materials to the site and from vehicles working at the plant during site preparation, interior reconstruction, and equipment erection. Vehicles greater than 10,000 pounds will be required to meet Minnesota Noise Standards for sound levels. The contractor is required to work with University management if certain construction activities may generate disruptive noise or vibration. During operation, two noise generating elements will be located outside of the Main Plant Building: the electric natural gas compressor and emergency steam vents. The compressor will operate any time that the combustion turbine generator combusts natural gas. The steam vents will operate very infrequently. Both systems are required to meet a noise standard of 85 decibels at a distance of 3 feet. The nearest occupied building is Education Sciences, which is located approximately 250 feet east of the planned compressor location. The nearest residence is Sanford Hall, which is approximately 500 feet north of the compressor location. Each building is situated 60 to 80 feet above Main Plant ground level. Minneapolis, Minnesota 32 Worksheet

35 As a general rule, noise perception dissipates six decibels each time distance to the listener doubles. It is estimated that noise levels will be less than 50 decibels at distances between 200 and 500 feet from the compressor (36 dba reduction at a distance of 192 feet from the source). 18. Transportation a. Describe traffic-related aspects of project construction and operation. Include: 1) existing and proposed additional parking spaces, 2) estimated total average daily traffic generated, 3) estimated maximum peak hour traffic generated and time of occurrence, 4) indicate source of trip generation rates used in the estimates, and 5) availability of transit and/or other alternative transportation modes. 1. There will be no new parking spaces. There are currently eight existing parking spaces. 2. It is estimated that there will be 15 trips per day during construction, and trips per day during operation. 3. Estimated maximum peak hour traffic generated and time of occurrence: 6:00 am 4:00 pm during construction; 7:00 am 3:00 pm during operation. 4. Trip generation rates are based on number of workers during construction, and number of employee during operation. 5. There is availability of transit and/or transportation modes. b. Discuss the effect on traffic congestion on affected roads and describe any traffic improvements necessary. The analysis must discuss the project s impact on the regional transportation system. No traffic congestion is anticipated based on the number of vehicles traveling to and from the project site. c. Identify measures that will be taken to minimize or mitigate project related transportation effects. There will be little change in number of vehicles traveling to and from the project site, therefore no measures are needed to minimize or mitigate project related transportation effects. 19. Cumulative potential effects: (Preparers can leave this item blank if cumulative potential effects are addressed under the applicable EAW Items) a. Describe the geographic scales and timeframes of the project related environmental effects that could combine with other environmental effects resulting in cumulative potential effects. The proposed project will operate for at least 20 years. Steam is distributed to the Minneapolis campus, thereby eliminating the need for individual boilers in each of the buildings. Efficient electricity production will reduce purchases by approximately 70% during the first year of operation, thereby reducing regional air pollution. Minneapolis, Minnesota 33 Worksheet

36 Stormwater and wastewater production will not have any significant effect in the local area or region. Wastewater will be managed by the regional sewer system. Stormwater quantities and quality will not significantly change over current practices (likely an improvement) and production. Air pollution will be emitted into the surrounding area, with impacts dissipating to 20% of maximum impacts within one mile of the facility. Air dispersion modeling has predicted that the facility will not significantly impact ambient air quality at the point of maximum impact. The facility is intended to operate as base-load, so little change in output is expected during its operating life. b. Describe any reasonably foreseeable future projects (for which a basis of expectation has been laid) that may interact with environmental effects of the proposed project within the geographic scales and timeframes identified above. Retirement of Southeast Boilers 3 and 4 will reduce the overall impact of air pollution in the geographic scale and timeframe indicated above. No other projects have been identified within one kilometer of the project. c. Discuss the nature of the cumulative potential effects and summarize any other available information relevant to determining whether there is potential for significant environmental effects due to these cumulative effects. Water Quality: Water will be supplied to the plant by the city of Minneapolis. Demand created by the project will represent a small percentage of overall demand on the utility. Wastewater from the Main CHP Plant will be discharged into the sanitary sewer and will be treated at the Publicly-Owned Treatment Works (POTW). Wastewater quantities will represent a small percentage of total deliveries to the wastewater treatment plant. Stormwater runoff is currently discharged directly into the storm sewer. SAFL baffles will be installed into catch basins to provide pretreatment to runoff prior to entering the stormwater sewer system and ultimately the Mississippi River. The new system will improve existing stormwater quality entering the sewer. Air Quality: The Twin Cities Metropolitan Area is currently in attainment with national and Minnesota Ambient Air Quality Standards. The proposed facility will contribute less than significant increases to ambient air pollutant concentrations in the surrounding area and will not affect current attainment status. The Main Plant will replace the Southeast Steam Plant as the primary base load steam source for the Minneapolis campus. Worst-case allowable hourly emissions will be reduced because two coal-fired boilers at the existing Southeast Plant will be retired once the Main Plant begins operation. Actual emissions from the Southeast Plant will be dramatically reduced when the Main Plant is in operation. Minneapolis, Minnesota 34 Worksheet

37 Main CHP Plant allowable criteria pollutant air emissions are below Significant Emission Thresholds, as defined by the EPA as part of the pre-construction NSR Program. Screening model results indicate that ambient air quality impacts will be less than Significant Increase Levels as defined by NSR. Regional greenhouse gas emissions will be reduced due to a combination of the inherently lowemitting design of the system and reduced electricity purchases from the local utility. Traffic: It is not expected that the plant will have a measurable impact on traffic in the area. Wildlife: It is not expected that the plant will have a measurable impact on wildlife in the area. Solid and Hazardous Waste: It is not expected that the plant will have a measurable impact on waste management in the Twin Cities. Air pollution control catalysts may need to be replaced every 40,000 operating hours. The catalyst material will be recycled if appropriate, or managed as required by state and federal rules. 20. Other potential environmental effects: If the project may cause any additional environmental effects not addressed by items 1 to 19, describe the effects here, discuss the how the environment will be affected, and identify measures that will be taken to minimize and mitigate these effects. The University recognizes that the facility will operate in the middle of an urban area. Surrounding communities include low-income residences, minority populations (including those that do not speak English as their native language of birth) and other people who may be underrepresented or have limited access to project information. In addition, other interested parties surround the facility, including property owners, developers and businesses. The University has recognized the importance of reaching these diverse and high-density populations. An outreach plan has been developed and three public meetings have been held to date. The University also intendeds to contact neighborhood organizations and other recognized interested parties regarding the public comments period available for this document. Minneapolis, Minnesota 35 Worksheet

38

39 Main Plant - Combined Heat and Power Ê. 0 10,000 20,000 40,000 Feet Figure 1 Main Plant - Combined Heat and Power Project University of Minnesota Hennepin County, Minnesota

40 ² 2,000 1, ,000 Feet Figure 2 University of Minnesota Combined Heat and Power Plant 1180 Main Street SE Minneapolis, Minnesota

41

42 Map is from the Panel 0376F provided by FEMA as part of their Flood Insurance Map series. CHPP Building Location Figure 4 FEMA Flood Insurance Rate Map Panel 0376F Hennepin County, MN

43 Old Main Heating Plant Proposed Main Combined Heat and Power Plant Figure 5 Current and Proposed Site Images

44 FIGURE 6. Main CHP Draft Stormwater Plan

45 Appendix A

46 Appendix B

47 Minnesota Department of Natural Resources Division of Ecological and Water Resources, Box Lafayette Road Appendix C St. Paul, Minnesota Phone: (651) lisa.joyal@state.mn.us September 4, 2013 Correspondence # ERDB Ms. Van-Anh Thai University of Minnesota rd Avenue SE Minneapolis, MN RE: Natural Heritage Review of the proposed U of M Heat & Power Plant, T29N R24W Section 24; Hennepin County Dear Ms. Thai, As requested, the Minnesota Natural Heritage Information System has been queried to determine if any rare species or other significant natural features are known to occur within an approximate one-mile radius of the proposed project. Based on this query, rare features have been documented within the search area (for details, see the enclosed database reports; please visit the Rare Species Guide at for more information on the biology, habitat use, and conservation measures of these rare species). Please note that the following rare features may be adversely affected by the proposed project: Several rare mussels, including the Spike (Elliptio dilatata) and the Wartyback (Quadrula nodulata), both state-listed threatened species, have been documented in the Mississippi River in the vicinity of the proposed project. As mussels are particularly vulnerable to deterioration in water quality, especially increased siltation, it is important that effective erosion prevention and sediment control practices be implemented and maintained near the river. The Environmental Assessment Worksheet should address whether the proposed project has the potential to adversely affect the above rare features and, if so, any avoidance or mitigation measures that will be implemented. The Natural Heritage Information System (NHIS), a collection of databases that contains information about Minnesota s rare natural features, is maintained by the Division of Ecological and Water Resources, Department of Natural Resources. The NHIS is continually updated as new information becomes available, and is the most complete source of data on Minnesota's rare or otherwise significant species, native plant communities, and other natural features. However, the NHIS is not an exhaustive inventory and thus does not represent all of the occurrences of rare features within the state. Therefore, ecologically significant features for which we have no records may exist within the project area. If additional information becomes available regarding rare features in the vicinity of the project, further review may be necessary. The enclosed results include an Index Report and a Detailed Report of records in the Rare Features Database, the main database of the NHIS. To control the release of specific location information, which might result in the destruction of a rare feature, both reports are copyrighted. The Index Report provides rare feature locations only to the nearest section, and may be reprinted, unaltered, in an environmental review document (e.g., EAW or EIS), municipal natural resource plan, or report compiled by your company for the project listed above. If you wish to reproduce AN EQUAL OPPORTUNITY EMPLOYER