AIR EMISSION PERMIT NO Major Amendment IS ISSUED TO. Mayo Foundation

AIR EMISSION PERMIT NO. 10900008-003 Major Amendment IS ISSUED TO Mayo Foundation SAINT MARYS HOSPITAL 1216 Second Street Southwest Rochester, Olmsted County, Minnesota 55902 The emission units, control equipment and emission stacks at the stationary source authorized in this permit amendment are described in the Permit Applications Table. This administrative amendment permit supersedes Air Emission Operating Permit No. 10900008-002, and authorizes the Permittee to operate and modify the stationary source at the address listed above unless otherwise noted in Table A. The Permittee must comply with all the conditions of the permit. Any changes or modifications to the stationary source must be performed in compliance with Minn. R. 7007.1150 to 7007.1500. Any additions or changes to conditions incorporated into Minnesota s State Implementation Plan (SIP) under 40 CFR 52.1220, designated Title I: SIP for SO 2 must go through the federal SIP approval process before becoming effective. Terms used in the permit are as defined in the state air pollution control rules unless the term is explicitly defined in the permit. Unless otherwise indicated, all the Minnesota rules cited as the origin of the permit terms are incorporated into the SIP under 40 CFR 52.1220 and as such as are enforceable by U.S. Environmental Protection Agency (EPA) Administrator or citizens under the Clean Air Act. Permit Type: Federal; Pt. 70/Major for New Source Review; Title I SIP Conditions for SO 2 Operating Permit Issue Date: July 23, 2003 Administrative Amendment Issue Date: March 1, 2010 Expiration Date: July 23, 2008* Title I Conditions do not expire. Each new or revised condition designated Title I Condition: SIP for SO 2 is not effective or enforceable until approved by EPA as a SIP revision under Title I of the Clean Air Act. * The Permittee may continue to operate this facility after the expiration date of the permit, per the provision under Minn. R. 7007.0450, subp. 3. (Title V Reissuance Application was received January 23, 2008.) Don Smith, P.E., Manager Air Quality Permits Section Industrial Division for Paul Eger Commissioner Minnesota Pollution Control Agency TDD (for hearing and speech impaired only): (651) 282-5332 Printed on recycled paper containing at least 10% fibers from paper recycled by consumers

Permit Applications Table Permit Type Application Date Permit Action Total Facility Operating Permit December 15, 1995, & December 9, 2002 001 Major Amendment March 27, 2009 002 Administrative Amendment Not Applicable MPCA Initiated 003

TABLE OF CONTENTS Notice to the Permittee Permit Shield Facility Description Amendment Description Table A: Limits and Other Requirements Table B: Submittals Table C: Compliance Schedule not used in this permit Appendices Appendix B Updated 2009 SO 2 Modeling Parameters Appendix C Insignificant Activities

NOTICE TO THE PERMITTEE: Your stationary source may be subject to the requirements of the Minnesota Pollution Control Agency s (MPCA) solid waste, hazardous waste, and water quality programs. If you wish to obtain information on these programs, including information on obtaining any required permits, please contact the MPCA general information number at: Metro Area 651-296-6300 Outside Metro Area 1-800-657-3864 TTY 651-282-5332 The rules governing these programs are contained in Minn. R. chs. 7000-7105. Written questions may be sent to: Minnesota Pollution Control Agency, 520 Lafayette Road North, St. Paul, Minnesota 55155-4194. Questions about this air emission permit or about air quality requirements can also be directed to the telephone numbers and address listed above. PERMIT SHIELD: Subject to the limitations in Minn. R. 7007.1800, compliance with the conditions of this permit shall be deemed compliance with the specific provision of the applicable requirement identified in the permit as the basis of each condition. Subject to the limitations of Minn. R. 7007.1800 and 7017.0100, subp. 2, notwithstanding the conditions of this permit specifying compliance practices for applicable requirements, any person (including the Permittee) may also use other credible evidence to establish compliance or noncompliance with applicable requirements.

FACILITY DESCRIPTION: St. Mary s is a tertiary care hospital which includes several buildings located on a 49 acre campus. The primary emission units at the facility are three identical boilers which exhaust through a common stack, one cogeneration turbine, and two emergency generators. Each boiler combusts natural gas with distillate fuel as backup. The cogeneration turbine burns only natural gas. One generator burns only distillate oil; the other can burn distillate oil or natural gas (with a small amount of distillate oil; dual fuel). While St. Mary s is owned and operated by the Mayo Foundation, it is not contiguous with the majority of the Mayo facilities in Rochester, and thus is a separate source under the New Source Review and Part 70 regulations. The facility is an existing major source under New Source Review and a minor HAP source. The facility is located in an area that was previously designated as non-attainment for SO 2. However, the area currently meets the ambient air quality standards, and was officially redesignated as attainment on May 8, 2001. The facility has been subject to a federally enforceable permit (No. 989-91-OT-2; part of Minnesota s state implementation plan, or SIP, for attaining ambient air quality standards) containing requirements contributing to the correction of the non-attainment problem and the ultimate redesignation. The requirements of that permit were incorporated into the title V operating permit No. 10900008-001, as non-expiring Title I conditions. Permit No. 10900008-002, replaces permit No. 109000008-001, and will ultimately replace permit No. 989-91-OT-2 and be incorporated into the SIP (sometime after issuance of permit No. 10900008-002). PER 002 AMENDMENT DESCRIPTION: This is a major amendment to an existing major source operating permit. This permit amendment authorizes the Permittee to install a 2500 KW reciprocating internal combustion engine (RICE) electric generator, and reduces the allowable diesel fuel sulfur content for two existing electric generators (EU 004 and EU 005). The new RICE is referred to as EU 012/Generator 7. The RICE is a compression ignition nonemergency 2007-2010 model year diesel engine with a displacement less than 10 liters per cylinder, and certified by the manufacturer to meet part 60, subpart IIII table 1 emission limits. PER 003 AMENDMENT DESCRIPTION: This administrative amendment corrects a typographical error in permit No. 10900008-002. The error was in the third requirement on page A-8 and pertained to the termination date for the 500 part per million by weight diesel fuel sulfur content limit. Permit No. 10900008-002, listed the date incorrectly as September 20, 2010. The date is corrected to September 30, 2010, by this administrative amendment.

TABLE A: LIMITS AND OTHER REQUIREMENTS A-1 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Table A contains limits and other requirements with which your facility must comply. The limits are located in the first column of the table (What To do). The limits can be emission limits or operational limits. This column also contains the actions that you must take and the records you must keep to show that you are complying with the limits. The second column of Table A (Why to do it) lists the regulatory basis for these limits. Appendices included as conditions of your permit are listed in Table A under total facility requirements. Subject Item: Total Facility What to do SITE-SPECIFIC REQUIREMENTS Why to do it Parameters Used in Modeling: The stack parameters used in the most recently approved modeling are listed in Appendix B of this permit. Before making any physical changes or changes in the method of operation which may affect parameters listed in Appendix B, the Permittee shall demonstrate to the MPCA that the SO2 plume dispersion characteristics following the physical change or change in method of operation will be equivalent to or better than the SO2 dispersion characteristics modeled using the parameters in Appendix B. The information submitted must include, at a minimum, the locations, heights, and diameters of the stacks, locations and dimensions of nearby buildings, the velocity and temperature of the gasses emitted, and the SO2 emission rates. If the information does not demonstrate equivalent or better dispersion characteristics, or if a conclusion cannot readily be made about the dispersion, the Permittee must remodel. ACTIVITIES NOT REQUIRING A MODIFICATION TO THE SIP: The Permittee is authorized to make changes to the facility in compliance with Minnesota Rules and without obtaining a modification to the SIP as long as the change does not increase from any emission point, the SO2 emission rates (in lb/hr) or overall SO2 emissions or alter equipment or parameters described in Appendix B, which forms the basis for the SO2 modeling, unless such alteration demonstrates equivalent or better dispersion characteristics. Deviations from requirements cited as "Title I Condition: SIP for SO2 NAAQS" shall be reported semiannually with the Semiannual Deviations Report required by this permit (See Table B). Reporting for these conditions shall occur even if there were no deviations for the reporting period. State Implementation Plan Recordkeeping: Retain all records at the stationary source for a period of five years from the date of the required monitoring, sample, measurement, or report that corresponds with a "Title I Condition: SIP for SO2 NAAQS" requirement. The facility currently uses ozone-depleting substances as defined in 40 CFR pt. 82. Sections 601-618 of the 1990 Clean Air Act Amendments and 40 CFR pt. 82 may apply to your facility. Read Sections 601-618 and 40 CFR pt. 82 to determine all the requirements that apply to your facility. DETERMINING IF A PROJECT/MODIFICATION IS SUBJECT TO NSR These requirements apply if a reasonable possibility (RP) as defined in 40 CFR Section 52.21(r)(6)(vi) exists that a proposed project, analyzed using the actual-to-projected-actual (ATPA) test (either by itself or as part of the hybrid test at Section 52.21(a)(2)(iv)(f)) and found to not be part of a major modification, may result in a significant emissions increase (SEI). If the ATPA test is not used for the project, or if there is no RP that the proposed project could result in a SEI, these requirements do not apply to that project. The Permittee is only subject to the Preconstruction Documentation requirement for a project where a RP occurs only within the meaning of Section 52.2(r)(6)(vi)(a). and MN State Implementation Plan and MN State Implementation Plan and MN State Implementation Plan and MN State Implementation Plan 40 CFR pt. 82 Title I Condition: 40 CFR Section 52.21(r)(6); Minn. R. 7007.3000; Minn. R. 7007.0800, subp. 2 Even though a particular modification is not subject to New Source Review (NSR), or where there isn't a RP that a proposed project could result in a SEI, a permit amendment, recordkeeping, or notification may still be required by Minn. R. 7007.1150-7007.1500.

TABLE A: LIMITS AND OTHER REQUIREMENTS A-2 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Preconstruction Documentation -- Before beginning actual construction on a project, the Permittee shall document the following: 1. Project description 2. Identification of any emission unit (EU) whose emissions of an NSR pollutant could be affected 3. Pre-change potential emissions of any affected existing EU, and the projected post-change potential emissions of any affected existing or new EU. 4. A description of the applicability test used to determine that the project is not a major modification for any regulated NSR pollutant, including the baseline actual emissions, the projected actual emissions, the amount of emissions excluded due to increases not associated with the modification and that the EU could have accommodated during the baseline period, an explanation of why the amounts were excluded, and any creditable contemporaneous increases and decreases that were considered in the determination. Title I Condition: 40 CFR Section 52.21(r)(6); Minn. R. 7007.3000; Minn. R. 7007.1200, subp. 4; Minn. R. 7007.0800, subps. 4 & 5 The Permittee shall maintain records of this documentation. The Permittee shall monitor the actual emissions of any regulated NSR pollutant that could increase as a result of the project and that were analyzed using the ATPA test, and the potential emissions of any regulated NSR pollutant that could increase as a result of the project and that were analyzed using potential emissions in the hybrid test. The Permittee shall calculate and maintain a record of the sum of the actual and potential (if the hybrid test was used in the analysis) emissions of the regulated pollutant, in tons per year on a calendar year basis, for a period of 5 years following resumption of regular operations after the change, or for a period of 10 years following resumption of regular operations after the change if the project increases the design capacity of or potential to emit of any unit associated with the project. The Permittee must submit a report to the Agency if the annual summed (actual, plus potential if used in hybrid test) emissions differ from the preconstruction projection and exceed the baseline actual emissions by a significant amount as listed at 40 CFR Section 52.21(b)(23). Such report shall be submitted to the Agency within 60 days after the end of the year in which the exceedances occur. The report shall contain: Title I Condition: 40 CFR Section 52.21(r)(6); Minn. R. 7007.3000; Minn. R. 7007.0800, subps. 4 & 5 Title I Condition: 40 CFR Section 52.21(r)(6); Minn. R. 7007.3000; Minn. R. 7007.0800, subps. 4 & 5 a. The name and ID number of the facility, and the name and telephone number of the facility contact person b. The annual emissions (actual, plus potential if any part of the project was analyzed using the hybrid test) for each pollutant for which the preconstruction projection and significant emissions increase are exceeded. c. Any other information, such as an explanation as to why the summed emissions differ from the preconstruction projection. OPERATIONAL REQUIREMENTS Circumvention: Do not install or use a device or means that conceals or dilutes emissions, which would otherwise violate a federal or state air pollution control rule, without reducing the total amount of pollutant emitted. Operation Changes: In any shutdown, breakdown, or deviation the Permittee shall immediately take all practical steps to modify operations to reduce the emission of any regulated air pollutant. The Commissioner may require feasible and practical modifications in the operation to reduce emissions of air pollutants. No emissions units that have an unreasonable shutdown or breakdown frequency of process or control equipment shall be permitted to operate. Fugitive Emissions: Do not cause or permit the handling, use, transporting, or storage of any material in a manner which may allow avoidable amounts of particulate matter to become airborne. Comply with all other requirements listed in Minn. R. 7011.0150. Noise: The Permittee shall comply with the noise standards set forth in Minn. R. 7030.0010 to 7030.0080 at all times during the operation of any emission units. This is a state only requirement and is not enforceable by the EPA Administrator or citizens under the Clean Air Act. Inspections: The Permittee shall comply with the inspection procedures and requirements as found in Minn. R. 7007.0800, subp. 9(A). The Permittee shall comply with the General Conditions listed in Minn. R. 7007.0800, subp. 16. RECORDKEEPING Minn. R. 7011.0020 Minn. R. 7019.1000, subp. 4 Minn. R. 7011.0150 Minn. R. 7030.0010-7030.0080 Minn. R. 7007.0800, subp. 9(A) Minn. R. 7007.0800, subp. 16

TABLE A: LIMITS AND OTHER REQUIREMENTS A-3 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Recordkeeping: Retain all records at the stationary source for a period of five (5) years from the date of monitoring, sample, measurement, or report. Records which must be retained at this location include all calibration and maintenance records, all original recordings for continuous monitoring instrumentation, and copies of all reports required by the permit. Records must conform to the requirements listed in Minn. R. 7007.0800, subp. 5(A). Recordkeeping: Maintain records describing any insignificant modifications (as required by Minn. R. 7007.1250, subp. 3) or changes contravening permit terms (as required by Minn. R. 7007.1350, subp. 2), including records of the emissions resulting from those changes. Recordkeeping: If the Permittee determines that no permit amendment or notification is required prior to making a change, the Permittee must retain records of all calculations required under Minn. R. 7007.1200. These records shall be kept for a period of five years from the date the change was made or until permit reissuance, whichever is longer. The records shall be kept at the stationary source for the current calendar year of operation and may be kept at the stationary source or office of the stationary source for all other years. The records may be maintained in either electronic or paper format. REPORTING/SUBMITTALS Shutdown Notifications: Notify the Commissioner at least 24 hours in advance of a planned shutdown of any control equipment or process equipment if the shutdown would cause any increase in the emissions of any regulated air pollutant. If the owner or operator does not have advance knowledge of the shutdown, notification shall be made to the Commissioner as soon as possible after the shutdown. However, notification is not required in the circumstances outlined in Items A, B, and C of Minn. R. 7019.1000, subp. 3. At the time of notification, the owner or operator shall inform the Commissioner of the cause of the shutdown and the estimated duration. The owner or operator shall notify the Commissioner when the shutdown is over. Breakdown Notifications: Notify the Commissioner within 24 hours of a breakdown of more than one hour duration of any control equipment or process equipment if the breakdown causes any increase in the emissions of any regulated air pollutant. The 24-hour time period starts when the breakdown was discovered or reasonably should have been discovered by the owner or operator. However, notification is not required in the circumstances outlined in Items A, B, and C of Minn. R. 7019.1000, subp. 2. Minn. R. 7007.0800, subp. 5(C) Minn. R. 7007.0800, subp. 5(B) Minn. R. 7007.1200, subp. 4 Minn. R. 7019.1000, subp. 3 Minn. R. 7019.1000, subp. 2 At the time of notification or as soon as possible thereafter, the owner or operator shall inform the Commissioner of the cause of the breakdown and the estimated duration. The owner or operator shall notify the Commissioner when the breakdown is over. Notification of Deviations Endangering Human Health or the Environment: As soon Minn. R. 7019.1000, subp. 1 as possible after discovery, notify the Commissioner or the state duty officer, either orally or by facsimile, of any deviation from permit conditions which could endanger human health or the environment. Notification of Deviations Endangering Human Health or the Environment Report: Minn. R. 7019.1000, subp. 1 Within 2 working days of discovery, notify the Commissioner in writing of any deviation from permit conditions which could endanger human health or the environment. Include the following information in this written description: 1. the cause of the deviation; 2. the exact dates of the period of the deviation, if the deviation has been corrected; 3. whether or not the deviation has been corrected; 4. the anticipated time by which the deviation is expected to be corrected, if not yet corrected; and 5. steps taken or planned to reduce, eliminate, and prevent reoccurrence of the deviation. Application for Permit Amendment: If a permit amendment is needed, submit an Minn. R. 7007.1150 through Minn. R. 7007.1500 application in accordance with the requirements of Minn. R. 7007.1150 through Minn. R. 7007.1500. Submittal dates vary, depending on the type of amendment needed.

TABLE A: LIMITS AND OTHER REQUIREMENTS A-4 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Application for a major permit amendment: If any EU 012 NOx emission factor verification test measures the EU 012 NOx emission factor at 1.040 g/hp-hr or greater, the Permittee shall submit an application for a major amendment. The application shall propose a reduction of the 2045 hr/yr EU 012 operating limit to a level that will limit EU 012 NOx emissions to no greater than 38.0 tons per year. Title I Condition: To avoid major modification status under 40 CFR Section 52.21(b)(2)(i) The application shall be submitted no later than 30 days after the Permittee's receipt of the MPCA letter approving the performance test results (i.e. a Notice of Verification). This requirement is repeated under Subject Item EU 012. Extension Requests: The Permittee may apply for an Administrative Amendment Minn. R. 7007.1400, subp. 1(H) to extend a deadline in a permit by no more than 120 days, provided the proposed deadline extension meets the requirements of Minn. R. 7007.1400, subp. 1(H). Emission Inventory Report: due on or before April 1 of each calendar year following Minn. R. 7019.3000 through Minn. R. 7019.3100 permit issuance. The report shall be submitted on a form approved by the Commissioner. Emission Fees: due 60 days after receipt of an MPCA bill. Minn. R. 7002.0005 through Minn. R. 7002.0095

TABLE A: LIMITS AND OTHER REQUIREMENTS A-5 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Subject Item: GP 001 Boilers Associated Items: EU 001 Boiler 1 EU 002 Boiler 2 EU 003 Boiler 3 EMISSION AND OPERATING LIMITS What to do Why to do it Fuel Used: The Permittee shall burn only natural gas or very low sulfur oil, as defined in 40 CFR Section 60.41b. Sulfur Content of Fuel: less than or equal to 0.5 percent by weight (very low sulfur oil, as defined in 40 CFR Section 60.41b) Nitrogen Oxides: less than or equal to 0.10 lbs/million Btu heat input using 30-day Rolling Average. This standard applies at all times. Opacity: less than or equal to 20 percent opacity using 6-minute Average, except for one 6-minute period per hour of not more than 27 percent opacity. This standard applies at all times except during periods of startup, shutdown, or malfunction. MONITORING REQUIREMENTS Sulfur Content of Fuel Oil: The Permittee shall obtain and maintain a fuel supplier receipt from the fuel oil supplier for each shipment of oil received, certifying that the oil meets the definition of very low sulfur oil as defined in 40 CFR Section 60.41b. The Permittee shall ensure that the fuel supplier uses an approved American Society of Testing and Materials (ASTM) method to determine the sulfur content of liquid fuels. NOx Emissions: The Permittee shall calibrate, maintain, and operate a continuous emission monitoring system (CEMS), and record the output of the system, for measuring NOx emissions discharged to the atmosphere. As allowed by 40 CFR 60.13(g), the Permittee operates one CEMS in the common duct for the three boilers. and MN State Implementation Plan and MN State Implementation Plan; 40 CFR Section 60.42b(j); Minn. R. 7011.0565 40 CFR Section 60.44b(a); 40 CFR Section 60.46b(a); Minn. R. 7011.0565 40 CFR Section 60.43b(f) and (g); 40 CFR Section 60.46b(a); Minn. R. 7011.0565 and MN State Implementation Plan; 40 CFR Section 60.42b(j)(2); Minn. R. 7011.0565 40 CFR Section 60.48b(b)(1), (c), and (d); 40 CFR Section 60.13(g); Minn. R. 7011.0565 The CEMS shall be operated and data recorded during all periods of operation of the boilers, except for CEMS breakdowns and repairs. Data is recorded during calibration checks, and zero and span adjustments. The 1-hour average NOx emission rates measured by the CEMS shall be expressed in lb/million Btu heat input, and shall be used to calculate the average emission rates. At least 2 data points must be used to calculate each 1-hour average. [For additional monitoring requirements, see Subject Item MR001.] When NOx emissions data are not obtained because of CEMs breakdowns or repairs, data will be obtained by using standby monitoring systems, Method 7 or 7A, or other approved reference methods to provide data for a minimum of 75% of the operating hours in each steam generating unit operating day, in at least 22 out of 30 successive steam generating unit operating days. Opacity: The Permittee shall calibrate, maintain, and operate a continuous monitoring system for measuring the opacity of emissions discharged to the atmosphere, and record the output of the system. 40 CFR Section 60.48b(f); Minn. R. 7011.0565 40 CFR Section 60.48b(a); 40 CFR Section 60.13(g); Minn. R. 7011.0565 As allowed by 40 CFR 60.13(g), the Permittee operates one COMS in the common duct for the three boilers. [For additional monitoring requirements, see Subject Item MR003.] PERFORMANCE TESTING REQUIREMENTS Upon request, the Permittee shall use a 30-day performance test to determine compliance with the NOx standard. During periods when performance tests are not requested, NOx emission data collected via the CEM shall be used to calculate a 30-day rolling average emission rate on a daily basis and used to prepare excess emission reports, but will not be used to determine compliance with the NOx emission standard. A new 30-day rolling average emission rate is calculated each steam generating unit operating day as the average of all of the hourly NOx emission data for the preceding 30 steam generating unit operating days. RECORDKEEPING AND REPORTING REQUIREMENTS 40 CFR Section 60.46b(e)(4); Minn. R. 7011.0565

TABLE A: LIMITS AND OTHER REQUIREMENTS A-6 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 The Permittee shall record and maintain records of the amounts of each fuel 40 CFR Section 60.49b(d); Minn. R. 7011.0565 combusted each day and calculate the annual capacity factor individually for distillate oil and natural gas. The annual capacity factor is determined on a 12-month rolling average basis with a new annual capacity factor calculated at the end of each calendar month. The Permittee shall maintain records of opacity. 40 CFR Section 60.49b(f); Minn. R. 7011.0565 The Permittee shall maintain records of the following information for each steam generating unit operating day: (1) Calendar date. (2) The average hourly NOx emission rates (expressed as NO2), in lb/million Btu heat input. (3) The 30-day average NOx emission rates calculated at the end of each steam generating unit operating day. (4) Identification of the steam generating unit operating days when the calculated 30-day average NOx emission rates are in excess of the NOx emission standard, including the reasons for the excess emissions and a description of corrective actions taken. (5) Identification of the steam generating unit operation days for which data have not been obtained including reasons for not obtaining sufficient data and a description of corrective actions taken. (6) Identification of the times when emission data have been excluded from the calculation of average emission rates and the reasons for excluding data. (7) Identification of "F" factor used for calculations, method of determination, and type of fuel combusted. (8) Identification of the times when the pollutant concentration exceeded full span of the CEMS. (9) Description of any modifications to the CEMS that could affect the ability of the CEMS to comply with Performance Specification 2 or 3. 40 CFR Section 60.49b(g); Minn. R. 7011.0565 continued from above

TABLE A: LIMITS AND OTHER REQUIREMENTS A-7 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Subject Item: GP 002 Boilers and Generators Associated Items: EU 001 Boiler 1 EU 002 Boiler 2 EU 003 Boiler 3 EU 004 Generator 5 EU 005 Generator 6 EU 012 Generator 7 (Non-emergency CI; <10 liter/cyl; 2500 kw) EMISSION LIMITS What to do Why to do it Sulfur Dioxide: less than or equal to 65.56 tons/year using 12-month Rolling Sum calculated monthly, as described below. MONITORING AND RECORDKEEPING Daily recordkeeping: Each day, record the total quantity of each type of fuel burned, and the sulfur content by weight of fuel oil in the tank from which oil is drawn on that day. Monthly Recordkeeping: SO2 Emissions Title I Condition: To avoid major source classification under 40 CFR Section 52.21 and Minn. R. 7007.3000 (limit originally set 3/27/91) Title I Condition: To avoid major source classification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Minn. R. 7007.0800, subp. 4 and 5 By the 15th day of each month, calculate and record the following: a. The total quantity of natural gas used in the GP002 units during the previous month (G), in million cubic feet b. The total quantity of sulfur contained in distillate oil used in the GP002 units during the month (S), in pounds, calculated by multiplying the gallons of oil with sulfur content "x" by "x" and the density of the oil (pounds/gallon), plus the gallons of oil with sulfur content "y" by "y" and the density of the oil, etc. c. The SO2 emissions for the previous months (E), in tons, using the following equation: E = 0.001 S + 0.0003 G, where: 0.001 = [(2 pounds of SO2/pound of sulfur) x (1 ton/2000 pounds)] and 0.0003 = [(0.6 pounds of SO2/million cubic feet of natural gas) x (1 ton/2000 pounds)] The 12-month rolling sum is calculated by summing the values of "E" calculated for the previous 12 months.

TABLE A: LIMITS AND OTHER REQUIREMENTS A-8 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Subject Item: EU 004 Generator 5 Associated Items: GP 002 Boilers and Generators SV 002 No. 5 Generator Stack What to do Why to do it Fuel: The Permittee shall burn only diesel fuel oil in the generator. and MN State Implementation Plan Opacity: less than or equal to 20 percent opacity once operating temperatures have Minn. R. 7011.2300, subp. 1 been attained Sulfur Content of Fuel: less than or equal to 500 parts per million by weight as specified at 40 CFR Section 80.510(a)(1) for nonroad, locomotive, and marine (NRLM) diesel fuel. This requirement is effective from the date of issuance of permit No. 10900008-002 through September 30, 2010. Sulfur Content of Fuel: less than or equal to 15 parts per million by weight as specified at 40 CFR Section 80.510(b)(1) for nonroad diesel fuel. This requirement is effective October 1, 2010. Diesel Fuel Sulfur Content Certification: The Permittee shall obtain and retain a written guarantee from the fuel supplier indicating that each shipment of diesel fuel delivered to the Facility for use in EU 004 will not contain more than 0.05 percent by weight sulfur (500 ppmw) through May 31, 2010, and no more than 0.0015 percent by weight sulfur (15 ppmw) after May 31, 2010. and MN State Implementation Plan; meets requirements of Minn. R. 7011.2300, subp. 2 and MN State Implementation Plan; meets requirements of Minn. R. 7011.2300, subp. 2 and MN State Implementation Plan

TABLE A: LIMITS AND OTHER REQUIREMENTS A-9 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Subject Item: EU 005 Generator 6 Associated Items: GP 002 Boilers and Generators SV 003 No. 6 Generator Stack What to do Why to do it Fuel: The Permittee shall burn only natural gas or diesel fuel oil in the generator. and MN State Implementation Plan Sulfur Content of Fuel: less than or equal to 500 parts per million by weight as specified at 40 CFR Section 80.510(a)(1) for nonroad, locomotive, and marine (NRLM) diesel fuel. This requirement is effective from the date of issuance of permit No. 10900008-002 through September 30, 2010. Sulfur Content of Fuel: less than or equal to 15 parts per million by weight as specified at 40 CFR Section 80.510(b)(1) for nonroad diesel fuel. This requirement is effective October 1, 2010. Opacity: less than or equal to 20 percent opacity once operating temperatures have been attained Operating Hours: less than or equal to 1040 hours/year using 12-month Rolling Sum Recordkeeping - Hours of Operation: By the 15th day of each month, calculate and record the hours the generator was operated during the previous month, and the total hours operated during the previous 12 months. Diesel Fuel Sulfur Content Certification: The Permittee shall obtain and retain a written guarantee from the fuel supplier indicating that each shipment of diesel fuel delivered to the Facility for use in EU 005 will not contain more than 0.05 percent by weight sulfur (500 ppmw) through May 31, 2010, and no more than 0.0015 percent by weight sulfur (15 ppmw) after May 31, 2010. and MN State Implementation Plan; meets requirements of Minn. R. 7011.2300, subp. 2 and MN State Implementation Plan; meets requirements of Minn. R. 7011.2300, subp. 2 Minn. R. 7011.2300, subp. 1 Title I Condition: To avoid classification as a major modification under 40 CFR Section 52.21 and Minn. R. 7007.3000. Title I Condition: To avoid classification as a major modification under 40 CFR Section 52.21 and Minn. R. 7007.3000. and MN State Implementation Plan

TABLE A: LIMITS AND OTHER REQUIREMENTS A-10 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Subject Item: EU 006 Turbine Engine Associated Items: SV 004 Cogeneration Turbine Stack What to do EMISSION LIMITS AND OPERATING REQUIREMENTS Why to do it Nitrogen Oxides: less than or equal to 190 parts per million at 15% O2, on a dry 40 CFR Section 60.332(a)(2); Minn. R. 7011.2350 basis Sulfur Content of Fuel: less than or equal to 0.8 percent by weight 40 CFR Section 60.333(b); Minn. R. 7011.2350 MONITORING REQUIREMENTS Custom Sulfur Monitoring Schedule: (A) Sulfur monitoring shall be conducted twice monthly (bi-weekly) for six (6) months. If the monitoring shows little variability in the fuel sulfur content, and indicates consistent compliance with 40 CFR Section 60.333(b), then sulfur monitoring shall be conducted once per calendar quarter. 40 CFR Section 60.334(b)(2); Minn. R. 7011.2350; EPA guidance memo dated August 14, 1987; EPA approval memo dated May 2, 2003 (B) Conduct fuel sulfur content monitoring once per quarer for six (6) quarters. If quarterly monitoring shows little variability in the fuel sulfur content, and indicates consistent compliance with the 40 CFR Section 60.333(b), the fuel sulfur content monitoring frequency may be reduced to a semi-annual basis (first and third quarters of the calendar year). Determination of Sulfur Content: ASTM D 1072-80 or 90 (Reapproved 1994), D 3031-81, D 4084-82 or 94, or D 3246-81, 92, or 96 shall be used to determine the sulfur content of gaseous fuels. 40 CFR Section 60.335(d); Minn. R. 7011.2350 Upon written approval of U.S. EPA, the following alternative method may be used to determine the sulfur content of pipeline natural gas: Gas Processors Association (GPA) Standard Method 2377-86, "Test for Hydrogen Sulfide and Carbon Dioxide in Natural Gas Using Length of Stain Tubes." The Permittee will use two length of stain tubes for each sample: one to detect hydrogen sulfide and one to detect mercaptans. Custom Nitrogen Monitoring Schedule: The requirement to monitor the nitrogen content of the fuel is waived, provided only pipeline quality natural gas is combusted in the turbine. The Permittee shall comply with the above monitoring requirements until such time as EPA promulgates revisions to the monitoring requirements in 40 CFR Part 60 Subpart GG. At that time, the Permittee may choose to comply with the monitoring requirements of the revised rule, provided the revised rule allows that choice. REPORTING REQUIREMENTS Notification of Noncompliance: Should any sulfur analysis indicate noncompliance with 40 CFR Section 60.333(b), as described in 40 CFR Section 60.334(c)(2), the Permittee shall notify the MPCA of such excess emissions and the custom fuel monitoring schedule shall be re-examined by the Administrator. Sulfur monitoring shall be conducted weekly during the interim period when the custom fuel monitoring schedule is being re-examined. Reporting: If there is a change in fuel supply, the Permittee shall notify the MPCA of such change for re-examination of the custom fuel monitoring schedule. A substantial change in fuel quality shall be considered as a change in fuel supply. Sulfur monitoring shall be conducted weekly during the interim period when the custom fuel monitoring schedule is being re-examined. 40 CFR Section 60.334(b)(2); Minn. R. 7011.2350; EPA guidance memo dated August 14, 1987; EPA approval letter dated May 2, 2003 40 CFR Sectio 60, Subpart GG; Minn. R. 7011.2350; Minn. R. 7007.0800, subp. 4 40 CFR Section 60.334(b)(2); Minn. R. 7011.2350; EPA guidance memo dated August 14, 1987; EPA approval letter dated May 2, 2003 40 CFR Section 60.334(b)(2); Minn. R. 7011.2350; EPA guidance memo dated August 14, 1987; EPA approval letter dated May 2, 2003

TABLE A: LIMITS AND OTHER REQUIREMENTS A-11 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Subject Item: EU 012 Generator 7 (Non-emergency CI; <10 liter/cyl; 2500 kw) Associated Items: GP 002 Boilers and Generators SV 005 No. 7 Generator Stack What to do LIMITS AND OPERATING RESTRICTIONS Why to do it Fuel: The Permittee shall burn only diesel fuel oil in the generator. and MN State Implementation Plan Fuel Requirements - Beginning October 1, 2007, the Permittee must use diesel fuel in EU 012 that meets the following requirements of 40 CFR Section 80.510(a): (1) Sulfur content maximum 500 ppm; and, (2) Cetane index minimum of 40 or aromatic content maximum of 35% by volume. Fuel Requirements - Beginning October 1, 2010, the Permittee must use diesel fuel in EU 012 that meets the following requirements of 40 CFR Section 80.510(b) for nonroad diesel fuel: and MN State Implementation Plan; 40 CFR Sections 60.4207(a) and 80.510(a); Minn. R. 7011.3520 and MN State Implementation Plan; 40 CFR Sections 60.4207(b) and 80.510(b); Minn. R. 7011.3520 (1) Sulfur content maximum 15 ppm (for nonroad diesel); and, (2) Cetane index minimum of 40 or aromatic content maximum of 35% by volume. The provisions of pt. 60, subp. IIII apply to the Permittee for operation of EU 012 because EU 012 was manufactured after April 1, 2006, and the Permittee commenced construction of EU 012 after July 11, 2005. For the purposes of pt. 60, subp. IIII, the date that construction commences is the date EU 012 is ordered by the Permittee. The Permittee must install an EU 012 engine that meets the requirements for 2007 model year engines. Opacity: less than or equal to 20 percent opacity once operating temperatures have been attained Operating Hours: less than or equal to 2045 hours/year using 12-month Rolling Sum calculated monthly by the last day of each month. This limit may be revised based on results from emission factor testing required by this permit. 40 CFR Section 60.4200(a)(2)(i); Minn. R. 7011.3520 40 CFR Section 60.4208(a); Minn. R. 7011.3520 Minn. R. 7011.2300, subp. 1 Title I Condition: To avoid major modification status under 40 CFR Section 52.21(b)(2)(i) During the initial 12 months of operation, the applicable operating hours limit as of month 'n' shall be the following: month 1 = 400 hrs month 2 = 650 hrs month 3 = 870 hrs month 4 = 1080 hrs month 5 = 1260 hrs month 6 = 1420 hrs month 7 = 1560 hrs month 8 = 1690 hrs month 9 = 1810 hrs month 10 = 1920 hrs month 11 = 2000 hrs month 12 = 2045 hrs MONITORING AND RECORDKEEPING REQUIREMENTS Recordkeeping - Operating Hours: by the last day of each calendar month, the Permittee shall: 1. record the EU 012 operating hours during the provious calendar month; and 2. calculate and record EU 012 operating hours during the previous 12-month period by summing the monthly operating hours records for the previous 12 months. Diesel Fuel Sulfur Content Certification: The Permittee shall obtain and retain a written guarantee from the fuel supplier indicating that each shipment of diesel fuel delivered to the Facility for use in EU 012 will not contain more than 0.05 percent by weight sulfur (500 ppmw) through May 31, 2010, and no more than 0.0015 percent by weight sulfur (15 ppmw) after May 31, 2010. PART 60 SUBPART IIII REQUIREMENTS Title I Condition: To avoid major modification status under 40 CFR Section 52.21(b)(2)(i); Minn. R. 7007.0800, subp. 4 and 5 and MN State Implementation Plan The Permittee must comply with the emission standards in Section 60.4201(b) and table 1 of subp. IIII when operating EU 012. 40 CFR Sections 60.4204(b) and 60.4201(b); pt. 60, subp. IIII table 1; Minn. R. 7011.3520 Hyrocarbons: less than or equal to 1.3 grams/kilowatt-hour 40 CFR Sections 60.4204(b) and 60.4201(b); pt. 60, subp. IIII table 1; Minn. R. 7011.3520

TABLE A: LIMITS AND OTHER REQUIREMENTS A-12 03/01/10 Facility Name: Permit Number: St Marys 10900008-003 Nitrogen Oxides: less than or equal to 9.2 grams/kilowatt-hour 40 CFR Sections 60.4204(b) and 60.4201(b); pt. 60, subp. IIII table 1; Minn. R. 7011.3520 Carbon Monoxide: less than or equal to 11.4 grams/kilowatt-hour 40 CFR Sections 60.4204(b) and 60.4201(b); pt. 60, subp. IIII table 1; Minn. R. 7011.3520 Total Particulate Matter: less than or equal to 0.54 grams/kilowatt-hour 40 CFR Sections 60.4204(b) and 60.4201(b); pt. 60, subp. IIII table 1; Minn. R. 7011.3520 The Permittee shall operate and maintain EU 012 so that it achieves the emission 40 CFR Section 60.4206; Minn. R. 7011.3520 standards as required in Section 60.4204 over the entire life of EU 012. The operation and maintenance shall be conducted according to the manufacturer's written instructions or procedures developed by the Permittee that are approved by the engine manufacturer. Pt. 60, Subp. IIII Compliance Requirements 40 CFR Section 60.4211(a) and (c); Minn. R. 7011.3520 The Permittee shall: 1. comply with the emission standards specified in subpart III; 2. operate and maintain EU 012 according to the manufacturer's written instructions or procedures developed by the Permittee that are approved by the engine manufacturer; 3. only change those settings that are permitted by the manufacturer; 4. meet the requirements of 40 CFR parts 89, 94 and/or 1068, as applicable. The Permittee shall purchase an engine certified to the emission standards in Section 60.4204(b) as applicable, for the same model year and maximum engine power. The engine must be installed and configured according to the manufacturer's specifications. Recordkeeping: Keep records of the following: (i) All notifications submitted to comply with part 60, subpart IIII and all documentation supporting any notification; (ii) Maintenance conducted on EU 012; (iii) Documentation from the manufacturer that EU 012 is certified to meet applicable emission standards in table 1 of part 60, subp. IIII. PART 63 SUBPART ZZZZ REQUIREMENTS EU 012 is a new affected source as defined under 40 CFR pt. 63, subp. ZZZZ, and the facility is an area source as defined at 40 CFR Section 63.2. The Permittee shall meet the requirements of subp. ZZZZ by meeting the requirements of pt. 60, subp. IIII. No further requirements of subp. ZZZZ apply to EU 012. PERFORMANCE TEST REQUIREMENTS Initial Performance Test: due 365 days after Initial Startup of EU 012 to verify the NOx emission factor (this is not a test for compliance determination). The NOx emission factor is 1.012E-02 grams per horsepower-hr (g/hp-hr). Application for a major permit amendment: If any EU 012 NOx emission factor verification test measures the EU 012 NOx emission factor at 1.040 g/hp-hr or greater, the Permittee shall submit an application for a major amendment. The application shall propose a reduction of the 2045 hr/yr EU 012 operating limit to a level that will limit EU 012 NOx emissions to no greater than 38.0 tons per year. 40 CFR Section 60.4214(a)(2); Minn. R. 7011.3520 40 CFR Section 63.6590 Minn. R. 7017.2020, subp. 1 Title I Condition: To avoid major modification status under 40 CFR Section 52.21(b)(2)(i) The application shall be submitted no later than 30 days after the Permittee's receipt of the MPCA letter approving the performance test results (i.e. a Notice of Verification). This requirement is repeated under Subject Item Total Facility.

TABLE A: LIMITS AND OTHER REQUIREMENTS A-13 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 Subject Item: MR 001 NOx Monitor Associated Items: CM 001 EU 001 Boiler 1 EU 002 Boiler 2 EU 003 Boiler 3 What to do Continuous Operation: CEMS must be operated and data recorded during all periods of emission unit operation including periods of emission unit start-up, shutdown, or malfunction except for periods of acceptable monitor downtime. This requirement applies whether or not a numerical emission limit applies during these periods. A CEMS must not be bypassed except in emergencies where failure to bypass would endanger human health, safety, or plant equipment. Acceptable monitor downtime includes reasonable periods as listed in Items A, B, C and D of Minn. R. 7017.1090, subp. 2. All CEMS shall complete a minimum of one cycle of operation (sampling, analyzing, and data recording) for each successive 15-minute period. The Permittee shall reduce all CEMS data to 1-hour averages. One hour averages shall be computed from four or more data points equally spaced over each 1-hour period. Data recorded during periods of CEMS breakdown, repair, calibration checks, and zero and span adjustments shall not be included in the data average. QA Plan: Develop and implement a written quality assurance plan that covers each CEMS. The plan shall be on site and available for inspection within 30 days after monitor certification. The plan shall contain all of the information required by 40CFR 60, App. F, section 3. CEMS Relative Accuracy Test Audit (RATA): due before end of each calendar year following CEM Certification Test, except as noted in Minn. R. 7017.1170, subp. 5. Follow the procedures in 40 CFR Section 60, Appendix F. Relative Accuracy Test Audit (RATA) Notification: due 30 days before CEMS Relative Accuracy Test Audit (RATA)). Notification may be made by fax, mail, electronic mail, or hand delivered. This is state-only requirement and is not enforceable by EPA or citizens under the Clean Air Act. Relative Accuracy Test Audit (RATA) Results Summary: due 30 days after end of each calender quarter in which the annual CEMS RATA was conducted. This is state-only requirement and is not enforceable by EPA or citizens under the Clean Air Act. CEMS Daily Calibration Drift (CD) Test: The Permittee shall automatically check the zero (or low level value between 0 and 20 percent of span value) and span (50 to 100 percent of span value) calibration drifts at least once daily in accordance with a written procedure. The zero and span must, as a minimum, be adjusted whenever either the 24-hour zero drift or the 24-hour span drift exceeds two times the limit from Appendix B of 40 CFR 60. CEMS Cylinder Gas Audit (CGA): due before end of each calendar half-year following CEM Certification Test, using a form approved by the commissioner, except that a CGA is not required during any half-year in which a RATA is performed. Cylinder Gas Audit (CGA) Results Summary: due 30 days after end of each calendar quarter following Cylinder Gas Audit (CGA). This is state-only requirement and is not enforceable by EPA or citizens under the Clean Air Act. Recordkeeping: The owner or operator must retain records of all CEMS monitoring data and support information for a period of five years from the date of the monitoring sample, measurement or report. Records shall be kept at the source. Records of Startup, Shutdown, or Malfunction: Any owner or operator subject to the provisions of this part shall maintain records of the occurrence and duration of any startup, shutdown, or malfunction in the operation of an affected facility; any malfunction of the air pollution control equipment; or any periods during which a continuous monitoring system or monitoring device is inoperative. Why to do it 40 CFR Section 60.13(e), Minn. R. 7017.1090, subp. 1; Minn. R. 7007.0800, subp. 4 40 CFR Section 60.13(e)(2); 40 CFR Section 60.13(h); Minn. R. 7017.1140; Minn. R. 7017.1160; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1170, subp. 2; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1170, subp. 5; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1180, subp. 2 Minn. R. 7017.1180, subp. 3 40 CFR Section 60.13(d)(1); Minn. R. 7017.1170, subp. 3; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1170, subp. 4; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1180, subp.1 40 CFR Section 60.7(f); Minn. R. 7017.1130; Minn. R. 7007.0800, subp. 4 40 CFR Section 60.7(b)

TABLE A: LIMITS AND OTHER REQUIREMENTS A-14 03/01/10 Facility Name: St Marys Permit Number: 10900008-003 CEMS Recertification Test: Recertification of a previously certified CEMS is required if the monitor undergoes a change invalidating its certification. Any of the following changes to a certified CEMS invalidates the certification status of the monitoring system: A. replacement of the analyzer; B. change in location or orientation of the sampling probe or site; C. modification to the flue gas handling system which changes its flow characteristics; or D. a change that in the commissioner's judgement siginficantly affects the ability of the stem to measure or record the pollutant concentration, or volumetric gas flow. CEMS Recertification Test Pretest Meeting: due 7 days before CEMS Recertification Test. This is a state-only requirement and is not enforceable by EPA or citizens under the Clean Air Act. CEMS Recertification Test Plan: due 30 days before CEMS Recertification Test. CEMS Recertification Test Report: due 45 days after CEMS Recertification Test CEMS Recertification Test Report - Microfiche Copy: due 105 days after CEMS Recertification Test. This is a state-only requirement and is not enforceable by EPA or citizens under the Clean Air Act. 40 CFR Section 60.13(b); Minn. R. 7017.1050, subp. 1; Minn. R. 7007.0800, subp. 4 Minn. R. 7017.1060, subp. 3 40 CFR Section 60.7(a)(5); Minn. R. 7017.1060, subp. 1 & 2 Minn. R. 7017.1080, subp. 1, 2, & 4; 40CFR 60.13(c)(2) Minn. R. 7017.1080, subp. 3