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Technical Support Document, Permit Number: 13700027- 010 of 16

Technical Support Document

For DRAFT Air Emission Permit No. 13700027- 010

This technical support document (TSD) is intended for all parties interested in the draft permit and to meet the requirements that have been set forth by the federal and state regulations (40 CFR § 70.7(a)(5) and Minn. R. 7007.0850, subp. 1). The purpose of this document is to provide the legal and factual justification for each applicable requirement or policy decision considered in the preliminary determination to issue the draft permit.

1. General information

1.1 Applicant and stationary source location:

Table 1. Applicant and Source Address

Applicant/Address Stationary Source/Address

(SIC Code: 4911, 4961)

Hibbing Public Utilities Commission 1902 6

th Avenue East

Hibbing, Minnesota 55746

Laurentian Energy Authority LLC 618 2

nd Street South

Virginia, Minnesota 55792

Hibbing Public Utilities Commission 1902 6

th Avenue East

St. Louis County Hibbing, Minnesota 55746

Contact: Pete Karakash Phone: 218-262-7723

Consultant: Ann Curnow Phone: 612-347-7112

1.2 Facility description

The Hibbing Public Utilities Commission (HPUC) operates a co-generation facility for the city of Hibbing. The facility generates electricity that is sold to the grid and steam for space heating of businesses, schools, and residences. The HPUC power plant is located in downtown Hibbing and was originally constructed in 1919. The emission units at the source consist of three coal boilers, a wood-fired boiler, an ash-handling system, as well as the two natural gas-fired boilers located at the nearby Hibbing High School. The high school boilers are connected to the HPUC steam distribution system. The six boilers are labeled Boiler No. 1A, Boiler No. 2A, Boiler No. 3A, High School Boiler No. 1, High School Boiler No. 2, and Wood-Fired Boiler. Other air emission sources at the facility include a railcar/truck coal unloading station and an ash transfer system.

1.3 Description of the activities allowed by this permit action

This permit action is a major permit amendment under Minn. R. 7007.1500, subp. 2(B) and authorizes a modification of Boiler 3A, (EQUI 3). Natural gas burners will be installed on Boiler 3A to stabilize combustion during startup and shutdown operations. The addition of the gas burners will reduce the amount of upsets which lead to frequent startups and shutdowns. A onetime test burn of wood pellets in Boiler 3A is also authorized by this permit modification. The test burn will determine if the pellets are a viable fuel for the existing fuel handling system and boiler combustion chambers. Performance tests conducted during the test burn may be used to support a major permit modification to permanently add wood pellets as a fuel for Boiler 3A. This permit also incorporates 40 CFR pt. 63, subp. DDDDD (Major Source Boiler MACT) compliance requirements for the facility’s six affected boilers.


1.4 Facility emissions:

Table 2. Title I emissions summary – actual to projected actual emissions test

Pollutant Projected actual emissions * (tpy)

Baseline actual emissions ** (tpy)

Projected emissions increase including excludables (tpy)

Projected Limited emissions increase including excludables (tpy)

NSR significant thresholds for major sources (tpy)

NSR review required? (Yes/No)

PM 9.16 62.93 -53.77 -3.63 25 No PM10 9.16 40.36 -31.19 -1.14 15 No

PM2.5 9.16 40.36 -31.19 -1.14 10 No

NOx 338.24 243.05 -2.25 -2.25 40 No

SO2 326.43 326.38 -2.45 -2.45 40 No

CO 192.23 138.09 -1.23 -1.23 100 No

Ozone (VOC) 1.94 1.38 0.00 0.00 40 No Lead 0.01 0.06 -0.05 0.00 0.6 No

CO2e**** 141,238 104,844 -722.50 -722.50 75,000 No

*Projected actual emissions as defined in 40 CFR § 52.21(b)(41). **Baseline actual emissions as defined in 40 CFR § 52.21(b)(48). This data is the sum of all CH-04a table 1 data for baseline actual emissions. ***Emissions that can be excluded as detailed in 40 CFR § 52.21(b)(41)(ii)(c). ****Carbon dioxide equivalents as defined in Minn. R. 7007.0100.

Table 3. Facility classification Classification Major Synthetic minor/area Minor/area

NSR X

Part 70 Permit Program X Part 63 NESHAP X

1.5 Changes to permit

The MPCA has a combined operating and construction permitting program under Minnesota Rules Chapter 7007, and under Minn. R. 7007.0800, the MPCA has authority to include additional requirements in a permit. Under that authority, the following changes to the permit are also made through this permit action:

Migrated permit conditions to Tempo (the MPCA’s new permitting database) from Delta (the previous database).

The permit has been updated to reflect current MPCA templates and standard citation formatting.

Completed requirements and the requirements for equipment that have been removed have been deleted.

The monitoring groups formerly known as GP 005 and GP 006 were removed, with the requirements being moved to the individual monitors. These requirements and submittals apply to monitors individually and compliance can be tracked more easily at this level.

Requirements for Continuous Emission/Opacity Monitoring Systems (CEMS/COMS) were updated to reflect the current MPCA templates and formatting.

Created new group, COMG 2, to hold general requirements and emissions averaging requirements from 40 CFR pt. 63, subps. A and DDDDD.

Fuel usage: used oil and oily rags fuel usage was restricted to startup times only for EQUIs 1, 2, and 3 (COMG 1).

Wood pellets were added as an allowable fuel for EQUI 3 to allow for a test burn of the fuel.

The high school boilers were classified as limited use under the Boiler MACT via a federally enforceable capacity factor of 10% each.


2. Regulatory and/or statutory basis 2.1 New source review (NSR)

The facility is an existing major source under New Source Review regulations. However, the potential emissions from the modification are not subject to NSR as shown in Table 2 because the limited emissions do not exceed the significant emission rate (SER) thresholds. Therefore, this permit action is not subject to the Prevention of Significant Deterioration (PSD) program requirements of NSR. The Permittee also accepted a limit on the amount of wood pellets that can be burned in Boiler 3A during the test burn. This limit will allow the Permittee to avoid a major modification under the NSR permitting rules.

2.2 Part 70 permit program

The facility is a major source under the Part 70 permit program. This permit action does not change this status. 2.3 New source performance standards (NSPS)

40 CFR pt. 60, subp. Db applies to steam generating units that have a heat input capacity greater than 100 MMBtu/hr that commence construction, modification, or reconstruction after June 19, 1984. Boiler 3A was constructed in 1974 and is an existing source under the subpart. The addition of the gas burners does not meet the definition of modification under 40 CFR § 60.2. Modification means any physical change in, or change in the method of operation of, an existing facility which increases the amount of any air pollutant (to which a standard applies) emitted into the atmosphere by that facility or which results in the emission of any air pollutant (to which a standard applies) into the atmosphere not previously emitted. 40 CFR pt. 60, subp. Db includes standards for SO2, PM, and NOX. The addition of the natural gas burners does not increase the emission rates of any of these pollutants and will not emit any new pollutants. 40 CFR pt. 60, subp. Db does not apply to Boiler 3A because the change does not qualify as a modification under the NSPS definition, and Boiler 3A will remain an existing source.

The Permittee has stated that no other New Source Performance Standards apply to the source.

2.4 National emission standards for hazardous air pollutants (NESHAP) 40 CFR pt. 63, subp. DDDDD applies to industrial, commercial, and institutional boilers and process heaters as defined in 40 CFR § 63.7575 that are located at, or are part of, a major source of HAPs. All boilers at the facility (EQUIs 1, 2, 3, 5, 6, 7) are subject to this subpart and are existing affected sources. Existing boilers are required to comply with this subpart no later than January 31, 2016. The previous permit (-009) contains a general requirement to comply with the subpart by the compliance date and all notifications required by the subpart by their respective due dates. This permit incorporates specific compliance options and requirements for each boiler.

40 CFR pt. 63, subp. UUUUU applies to coal or oil-fired electric utility steam generating units as defined in 40 CFR § 63.10042. A fossil fuel-fired unit that cogenerates steam and electricity and supplies more than one-third of its potential electric output capacity and more than 25 MWe output to any utility power distribution system for sale is considered an electric utility steam generating unit.

The boilers located at Hibbing Public Utilities Commission that are used to generate electricity are Boilers 1A, 2A, 3A, and the Wood-Fired Boiler (EQUIs 1, 2, 3, 5, 6, 7). The two high school boilers (EQUI 5 and EQUI 6) are used only for heating purposes. Boilers 1A, 2A, 3A, and the Wood-Fired Boiler are rated at approximately 17.8 MWe, 17.8 MWe, 21.4 MWe, and 19.4 MWe generating capacity respectively. These boilers generate steam that is fed to a single steam header that can then be routed to any of the three steam/turbine generators (rated at 9.4 MW, 18.4 MW, and 6.4 MW). Steam is extracted from a turbine stage to feed the district heating system, which takes precedence over the generation of electricity. The process of generating electricity and providing steam for heat or other industrial processes is accomplished via a topping cycle cogeneration process.


As no turbine/generator set is over 25 MWe output and no boiler is individually capable of producing the amount and quality of steam needed to produce 25 MWe for sale to a utility distribution system, under a cogeneration or non-cogeneration mode of operation, none of these boilers meet the definition of an electric utility steam generating unit. As each boiler does not meet the definition of an electric utility steam generating unit, 40 CFR pt. 63, subp. UUUUU does not apply to any of the boilers.

The Permittee has stated that no other national emission standards for hazardous air pollutants apply to the source.

2.7 Compliance assurance monitoring (CAM) While the boilers (EQUIs 1, 2, 3, and 7) are subject to CAM, this permit action only adds limitations for NOX under Section 112 (MACT standards) of the Clean Air Act. These standards contain compliance monitoring requirements equal to the monitoring requirements of 40 CFR § 64.4 (CAM). Therefore, CAM does not apply to this permit modification and the facility’s existing CAM plan was not updated.

2.8 Environmental review and air emissions risk analysis (AERA)

The facility does not trigger any of the requirements for the need to conduct environmental review, i.e. an Environmental Assessment Worksheet (EAW), and is not required to perform an AERA.

2.9 Minnesota state rules Portions of the facility are subject to the following Minnesota Standards of Performance:

Minn. R. 7011.0150 Preventing Particulate Matter from Becoming Airborne

Minn. R. 7011.0510 Standards of Performance for Existing Indirect Heating Equipment

Minn. R. 7011.0565 Standards of Performance for Industrial, Commercial, and Institutional Steam Generating Units

Minn. R. 7011.0710 Standards of Performance for Pre-1969 Industrial Process Equipment

Minn. R. 7011.0715 Standards of Performance for Post-1969 Industrial Process Equipment

Minn. R. 7011.1110 Standards of Performance for Existing Outstate Coal Handling Facilities

Table 4. Regulatory overview of units affected by the modification/permit amendment

Subject item* Applicable regulations Rationale

EQUI 1 (Boiler 1A)

40 CFR pt. 63, subp. DDDDDD

NESHAP for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters. Determination of applicable limits from rule:

Unit was constructed in 1952;

Heat input capacity is 216 MMBtu/hr;

Unit designed to burn coal/solid fossil fuel subcategory;

Stoker designed to burn solid fuel/coal is used;

Active oxygen trim system is used;

Dry electrostatic precipitator (ESP) is used on the unit.

Title I Condition: 40 CFR § 52.21(k)

Limits set for PM10 and time spent soot blowing to comply with national ambient air quality standards (NAAQS). Limits were derived from computer dispersion modeling required by the PSD program as a part of Permit 13700027-003.

Minn. R. 7009.0020 Limit set for SO2 to comply with NAAQS. Limit was derived from computer dispersion modeling done as part of Title V modeling to show compliance with the 1-hour SO2 standards as a part of Permit 13700027-009.

Minn. R. 7011.0510 Standards of Performance for Existing Indirect Heating Equipment. Limits set for PM, SO2, and opacity.

Minn. R. 7007.0800 Fuel use limited to bituminous and subbituminous coal, used oil, natural gas, and oily cellulose-based sorbents (including rags). Fuel usage is limited for used oil and oily cellulose-based sorbents (oily rags).


EQUI 2 (Boiler 2A)






Stoker designed to burn solid fuel is used;

Active oxygen trim system is not used;

Dry electrostatic precipitator is used on the unit.


Limits set for PM10 and time spent soot blowing to comply with the NAAQS. Limits were derived from computer dispersion modeling required by the PSD program in Permit 13700027-003.

Minn. R. 7009.0020 Limit set for SO2 to comply with the NAAQS. Limit was derived from computer dispersion modeling done as part of Title V modeling to show compliance with the 1-hour SO2 standards in Permit 13700027-009.


Minn. R. 7017.2025

Performance Test Operational Requirements and Limitations. Limit set on steam production based on performance test results. Limit is set based the most recent performance test that demonstrates compliance with applicable emission limitations.

Minn. R. 7007.0800 Fuel use limited to bituminous and subbituminous coal, used oil, natural gas, and oily rags. Fuel usage is limited for used oil and oily rags.

EQUI 3 (Boiler 3A)






Stoker designed to burn solid fuel/coal is used;


Dry electrostatic precipitator is used on the unit.


Limits set for PM10 and time spent soot blowing to comply with the NAAQS. Limits were derived from computer dispersion modeling required by the PSD program. This limit was established as part of Permit 13700027-003.

Minn. R. 7009.0020 Limit set for SO2 to comply with the NAAQS. Limit was derived from computer dispersion modeling done as part of Title V modeling to show compliance with the 1-hour SO2 standards in Permit 13700027-009.


Minn. R. 7017.2025

Performance Test Operational Requirements and Limitations. Limit set on steam production based on performance test results. Limit is set based the most recent performance test that demonstrates compliance with applicable emission limitations.

Minn. R. 7007.0800 Fuel use limited to bituminous and subbituminous coal, wood pellets, used oil, natural gas, and oily rags. Fuel usage is limited for wood pellets, used oil and oily rags.

EQUI 5 (High School Boiler 1)



Unit will be limited-use due to a federally enforceable capacity factor of 10%;

Unit was constructed in 1972


Unit designed to burn gas 1 fuel category


Minn. R. 7011.0510 Standards of Performance for Existing Indirect Heating Equipment. Limits set for PM and opacity.

Minn. R. 7007.0800 Fuel use limited to natural gas.


*Location of the requirement in the permit (e.g., EQUI 1, STRU 2,etc.).

The language 'This is a state-only requirement and is not enforceable by the U.S. Environmental Protection Agency (EPA) Administrator and citizens under the Clean Air Act' refers to permit requirements that are established only under state law and are not established under or required by the federal Clean Air Act. The language is to clarify the distinction between permit conditions that are required by federal law and those that are required only under state law. State law-only requirements are not enforceable by the EPA or by citizens under the federal Clean Air Act, but are fully enforceable by the MPCA and citizens under provisions of state law. The permit also includes Short Term Emergency and Testing (STET) operating hour limits for EQUIs 1, 2, 3, and 7. These limits are included to allow the boilers to operate up to 40 hours per year to demonstrate the Uniform Rating of Generating Equipment (URGE) capacity. These requirements are in place as part of an agreement the facility has with Midcontinent Independent System Operator, Inc. (MISO) which requires the facility to perform an URGE test of each generator for recording specific load and output data. The facility is required to maintain documentation of all STET operation to demonstrate compliance with the operating hours limit. Each boiler must still meet all applicable emission limits during STET operation.




Unit will be limited-use due to a federally enforceable capacity factor of 10%;

Unit was constructed in 1972


Unit designed to burn gas 1 fuel category


Minn. R. 7011.0510 Standards of Performance for Existing Indirect Heating Equipment. Limits set for PM and opacity.

Minn. R. 7007.0800 Fuel use limited to natural gas.

EQUI 7 (Wood Boiler)





Stoker unit designed to burn wet biomass/bio-based solid;

Active oxygen trim system is used;

Selective Non-catalytic Reduction (SNCR) system and dry ESP are used.

Title I Condition: 40 CFR § 52.21(j)

Limits were derived from a Best Available Control Technology (BACT) analysis required by the PSD program. These limits were established as part of Permit 13700027-003.

40 CFR pt. 60, subp. Db; Minn. R. 7011.0565

Standards of Performance for Industrial, Commercial, and Institutional Steam Generating Units. Limits set for PM, NOX, and opacity.

Limit to avoid mandatory EAW/AERA

Limit set on hours of operation when combusting wood to reduce annual emissions of CO to avoid environmental review per Minn. R. 4410.4300, subp. 15(A). This limit was established as part of Permit 13700027-007 to reduce the CO emissions increase from the modification to below 250 tpy. This is a state-only requirement and is not enforceable by the U.S. Environmental Protection Agency (EPA) Administrator and citizens under the Clean Air Act.

Minn. R. 7009.0020 Limit set for NO2 to comply with the NAAQS. Limit was derived from computer dispersion modeling done as part of Title V modeling to show compliance with the 1-hour NO2 standards.

Minn. R. 7007.0800 Limits set for allowable fuels and ammonia slip. Allowable fuel types that can be combusted are restricted to natural gas and untreated wood. Ammonia slip is limited to act as an indicator of effectiveness of the SNCR system.


3. Technical information

3.1 Calculations of potential to emit and emissions increase analysis

Boilers 3A (EQUI 3) is an existing emission unit and is the only unit affected by this permit modification. High school Boilers 1 and 2 (EQUIs 5 and 6) are not physically modified but this permit action establishes a federally enforceable capacity factor on each boiler to make them limited-use under the Boiler MACT standard.

A 90 MMBtu/hr natural gas auxiliary burner is being added to Boiler 3A (EQUI 3). The Permittee used the actual-to-projected-actual test for evaluating the natural gas emissions. For existing emission units, baseline actual emissions are defined in 40 CFR § 52.21(b)(48) with distinctions for existing units that are electric utility steam generating units (EGUs). For this purpose, EGUs are defined in 40 CFR § 52.21(b)(31) as any steam electric generating unit that is constructed for the purpose of supplying more than one-third of its potential electric output capacity and more than 25 MWe electrical output to any utility power distribution system for sale. As discussed in Section 2.4 of this TSD under NESHAP applicability, none of the boilers at the facility are above this numerical threshold.

In determining baseline actual emissions the Permittee followed procedures outlined in 40 CFR § 52.21(b)(48)(ii) and chose the following 24-month baseline periods:

January 1, 2005 through December 31, 2006 for PM10 and PM2.5 emissions;

January 1, 2007 through December 31, 2008 for PM and Lead emissions;

January 1, 2008 through December 31, 2009 for SO2 emissions; and

January 1, 2010 through December 31, 2011 for CO2e emissions.

January 1, 2013 through December 31, 2014 for NOX, CO, and VOC emissions. Different baseline periods are allowed for each pollutant per 40 CFR § 52.21(b)(48)(ii)(d). Baseline actual emissions are collected from emission inventory data. Particulate matter and lead baseline actual emissions are based on performance testing conducted for the boiler. SO2 baseline actual emissions were determined through emissions data collected by continuous monitors (EQUI 25, EQUI 27). All other baseline actual emission calculations are based on AP-42 emission factors. The facility keeps records of hours of operation and fuel use for each boiler. This historical operational data was used to establish the baseline actual emissions from Boiler 3A.

Emission factors for pollutants from the natural gas burner are taken from AP-42 for external combustion sources burning natural gas. Projected actual emission factors for the boiler when combusting coal are based on performance test data for particulates and lead, CEMS data for SO2, and AP-42 for CO, NOX and VOC. HPUC, which operates the boiler on behalf of Laurentian Energy Authority LLC, prepares an operating budget annually for the coming year. This budget contains the expected steam production for all boilers at the facility. Historical data was used to determine expected startup and shutdown events and to estimate the amount of natural gas combusted. The combination of the operating budget and historical data was used to calculate projected actual emissions for each pollutant from the boiler.

Attachment 1 to this TSD contains detailed spreadsheets describing the PTE of the Facility and the Title I emissions increase calculations for this modification. The calculations demonstrate that this modification is not a major modification for PSD.

3.2 Dispersion modeling The facility did not trigger the requirement to complete air dispersion modeling because no stack parameters listed in Appendix C of the permit were modified. As shown in Appendix B, PM10 emissions from EQUI 3 were modeled at 32 lb/hr. The potential emissions of the combined fuels (coal and natural gas) would be 20.89 lb PM10/hr, while natural gas only would be 0.67 lb/hr. It can therefore be reasonably assumed that the PM10 dispersion characteristics would be equivalent or better to that which was modeled and showed compliance with the NAAQS. Boiler 3A also modeled NOX emissions at 128.38 lb/hr, and the PTE of the combined fuels is 90.61 lb/hr.


Several operating restrictions were assumed when modeling was conducted in previous permit actions, so these have been incorporated as permit limits in the permit. Tables of the modeled parameters are included in the permit as appendices. The parameters listed in Appendices B and C of the permit describe the operation of the facility at maximum capacity. In other words, the flow rates and temperatures listed in the Appendices represent the minimum parameters at the maximum emission rates. The MPCA does not require any specific compliance demonstration with these parameters because they are worse-case conditions. The purpose of listing the parameters in the permit appendix is to provide a benchmark for determining if and when additional modeling is required.

3.3 Test burn of wood pellets in Boiler 3A

This permit action authorizes the Permittee to conduct a test burn of wood pellets in Boiler 3A, EQUI 3, to evaluate the use of wood pellets as a supplemental fuel. The wood pellets will be mixed with the coal to displace a certain percentage of the coal during the test. No modifications to the boiler or fuel handling systems in order to accommodate the wood pellets are authorized; the Permittee is evaluating whether the existing system is viable. If the test burn is successful, HPUC may apply for another permit amendment to authorize ongoing wood usage to reduce coal use in the future.

The Permittee must comply with all existing and new permit conditions during the test. A Title I Condition to restrict the test burn to 250 tons or less will ensure that the emissions from the test burn will be less than the SER under the NSR program. Wood pellet usage is also limited to 2.31 tons/hr, or 20% of the boiler’s total heat input capacity. This limit will reduce the risk of the wood pellets causing an upset in the boiler due to the difference in fuel properties of the coal and wood pellets. Performance tests for total PM, PM10, PM2.5, CO and VOC will be conducted during the test burn.

The test burn will not change the subcategory of the boiler under the Boiler MACT rule. A unit designed to burn biomass/bio-based solid subcategory includes any boiler or process heater that burns at least 10% biomass on an annual heat input basis. The 250 ton limit on wood pellets ensures that wood pellet usage would be far below 10% of the annual heat input. The lowest heat input to the boiler from the last 10 years is 618,165 MMBtu in 2012 and the 250 tons of wood pellets is equal to 5,370 MMBtu. However, the Permittee must meet all permit limits during the test burn, including new Boiler MACT conditions for the coal/solid fossil fuel subcategory and is required to perform a fuel analysis on all fuels used in the boiler for purposes other than startup and shutdown. If the Permittee is unable to show that the wood pellets do not increase the chlorine or mercury into the unit through the results of fuel analyses, then the performance tests for chlorine and/or mercury must be repeated while using wood pellets.

3.4 Mercury reduction plan The Permittee is subject to Minn. R. 7007.0502 and is an existing mercury source which does not qualify as an exemption under Minn. R. 7007.0502, subp. 3. A mercury reduction plan was submitted to the MPCA July 6, 2015. The plan includes reduction elements to ensure that each boiler will emit less than 5 pounds of mercury per year by the final compliance deadline of January 1, 2018. Based on prior performance tests, mercury emissions from Boiler 3A (EQUI 3) are of primary concern. The Permittee will conduct testing to determine feasibility, cost, and emission factors for the boiler when co-firing coal with wood pellets and/or natural gas. Based on these tests, the Permittee will be able to determine if fuel limits are needed to meet the mercury reduction targets.

No limits were added to the permit to comply with Minn. R. 7007.0502 in this permit action so the Permittee may establish emission factors for Boiler 3A (EQUI 3) while co-firing fuels. New requirements promulgated by 40 CFR pt. 63, subp. DDDDD will ensure that mercury emissions will be controlled to the maximum level possible for the units. Further permit requirements to comply with the Minnesota mercury reduction rule may be added to the permit at or before the reissuance of the Title V permit.


3.5 Monitoring In accordance with the Clean Air Act, it is the responsibility of the owner or operator of a facility to have sufficient knowledge of the facility to certify that the facility is in compliance with all applicable requirements.

In evaluating the monitoring included in the permit, the MPCA considered the following:

The likelihood of the facility violating the applicable requirements.

Whether add-on controls are necessary to meet the emission limits.

The variability of emissions over time.

The type of monitoring, process, maintenance, or control equipment data already available for the emission unit.

The technical and economic feasibility of possible periodic monitoring methods.

The kind of monitoring found on similar units elsewhere.

The table below summarizes the monitoring requirements associated with this amendment.

Table 5. Monitoring Subject item* Requirement (rule basis) Monitoring Discussion

Filterable PM ≤ 0.040 lbs/MMBtu heat input (NESHAP Limit)

Continuous opacity monitoring (COMS); Performance testing

EQUI 28 monitors the opacity of Boilers 1A and 2A. Continuous Monitoring Systems (CMS) must be operated at all times, including startup and shutdown. Operating load or steam generation data must be collected every 15 minutes. Initial performance testing is due 7/31/2016.

EQUI 1 (Boiler 1A)

Hydrochloric Acid ≤ 0.022 lbs/MMBtu heat input (NESHAP Limit)

Performance testing; Fuel analyses

Annual HCl performance tests are required following the initial test. The Permittee must establish the maximum chlorine fuel input during the initial fuel analysis.

Mercury ≤ 5.70×10-6

lbs/MMBtu heat input (NESHAP Limit)


Annual Mercury performance tests are required following the initial test. The Permittee must establish the maximum fuel input during the initial fuel analysis.

Carbon Monoxide ≤ 340 ppm at 3% O2 (NESHAP Limit)

CO Continuous Emission Monitoring System (CEMS); O2 CEMS

An initial performance evaluation of the CO CEMS, EQUI 48, is required. A site specific monitoring plan is also required. The use of CEMS for CO and O2 is sufficient to have a reasonable assurance of compliance.

Opacity ≤ 10% (NESHAP Limit)

COMS The opacity shall be measured during the Filterable PM test. The use of COMS is sufficient to have a reasonable assurance of compliance.

PM10 ≤ 0.074 lbs/MMBtu, inclusive of soot blowing (24-hour average) Soot Blowing ≤ 120 minutes/calendar day (Title I Modeling Limit)

Performance testing for PM10; Control equipment O&M; Recordkeeping of soot blowing events

The Permittee is required to operate and maintain particulate matter control equipment any time the emission unit is in operation. Additionally, the Permittee must keep records of the date, time, and duration of each soot blowing event. These requirements, in addition to the performance testing for PM10 required for this emission unit is sufficient to have a reasonable assurance of compliance.

SO2 ≤ 194.40 lbs/hr (Title V Modeling Limit)

SO2 CEMS The use of CEMS for SO2 is sufficient to have a reasonable assurance of compliance.


Subject item* Requirement (rule basis) Monitoring Discussion

EQUI 1 (Boiler 1A)

PM ≤ 0.60 lbs/MMBtu SO2 ≤ 4.0 lbs/MMBtu when burning coal SO2 ≤ 2.0 lbs/MMBtu when burning oil Opacity ≤ 20% with exceptions (Minn. R. 7011.0510)

Performance testing for PM; Control equipment O&M; SO2 CEMS; COMS

The Permittee is required to operate and maintain particulate matter control equipment any time the emission unit is in operation, use CEMS for SO2, and use COMS to measure opacity. These requirements, in addition to the performance testing for PM required for this emission unit is sufficient to have a reasonable assurance of compliance.

Steam Flow ≤ 114,318 lbs/hr (8-hour block average) (Minn. R. 7017.2025)

Flow rate monitoring and recordkeeping; Daily calculations

The Permittee is required to read and record steam flow rates every 15 minutes while the emission unit is operating. These readings can be taken from the SO2 CEMS data or may be taken independently. The Permittee is also required to calculate and record the three 8-hour block average steam flows for the previous day. These requirements are sufficient to have a reasonable assurance of compliance.

Fuels restricted to bituminous coal, subbituminous coal, used oil, natural gas and oily cellulose-based sorbents (including rags) Used Oil Usage ≤ 77.0 gal/hr Used Oil Usage ≤ 5% total heat input to boiler (Minn. R. 7007.0800)

Recordkeeping of daily fuel usage; Monthly calculations

The Permittee is required to record the quantity of used oil combusted in the boiler on an hourly basis. In addition, Boilers 1A, 2A, and 3A are subject to a combined usage limit as documented in COMG 1 and are required to calculate the total amount used for the previous 12 months. These requirements are sufficient to have a reasonable assurance of compliance.

EQUI 2 (Boiler 2A)

Filterable PM ≤ 0.040 lbs/MMBtu heat input (NESHAP Limit)

COMS; Performance testing

EQUI 28 monitors the opacity of Boilers 1A and 2A. CMS must be operated at all times, including startup and shutdown. Operating load or steam generation data must be collected every 15 minutes. Initial performance testing is due 7/31/2016.

Hydrochloric Acid ≤ 0.022 lbs/MMBtu heat input (NESHAP Limit)


Annual HCl performance tests are required following the initial test which is due 7/31/2016. The Permittee must establish the maximum chlorine fuel input during the initial fuel analysis.

Mercury ≤ 5.70×10-6

lbs/MMBtu heat input (NESHAP Limit)


Annual Mercury performance tests are required following the initial test which is due 7/31/2016. The Permittee must establish the maximum fuel input during the initial fuel analysis.


CO CEMS; O2 CEMS






EQUI 2 (Boiler 2A)












Fuels restricted to bituminous and subbituminous coal, used oil, natural gas and oily cellulose-based sorbents (including rags) Used Oil Usage ≤ 77.0 gal/hr Used Oil Usage ≤ 5% total heat input to boiler (Minn. R. 7007.0800)



EQUI 3 (Boiler 3A)

Filterable PM ≤ 0.040 lb/MMBtu heat input (NESHAP Limit)

COMS; Performance testing

EQUI 29 monitors the opacity of Boiler 3A. CMS must be operated at all times, including startup and shutdown. Operating load or steam generation data must be collected every 15 minutes. Initial performance testing is due 7/31/2016.

Hydrochloric Acid ≤ 0.022 lb/MMBtu heat input (NESHAP Limit)


Annual HCl performance tests are required following the initial test which is due 7/31/2016. The Permittee must establish the maximum chlorine fuel input during the initial fuel analysis.

Mercury ≤ 5.70×10-6

lb/MMBtu heat input (NESHAP Limit)


Annual Mercury performance tests are required following the initial test which is due 7/31/2016. The Permittee must establish the maximum fuel input during the initial fuel analysis.


CO CEMS; O2 CEMS




EQUI 3 (Boiler 3A)














Fuels restricted to bituminous coal, subbituminous coal, used oil, natural gas oily cellulose-based sorbents (including rags), and wood pellets Used Oil Usage ≤ 77.0 gal/hr Used Oil Usage ≤ 5% total heat input to boiler (Minn. R. 7007.0800)



Fuel usage ≤ 250 tons of wood pellets – test burn to be completed by 12/31/2016 (Title I Condition to avoid major modification) Wood Pellet Fuel usage ≤ 2.31 tons/hr (Minn. R. 7007.0800)

Performance testing: PM, PM10, PM2.5, CO and VOCs during test burn of wood pellets Recordkeeping: calculate and record wood pellet usage

There are no standards of performance or other emissions standards for conducting test burns of alternative fuels. The MPCA has determined that a limit on wood pellet usage coupled with performance testing and recordkeeping is sufficient to determine compliance with existing limits and fuel restriction limits. An hourly limit reduces the risk of the wood pellets causing an upset.




Heat Input ≤ 31,536 MMBtu/yr (Title I Condition NESHAP)


This capacity factor is needed to classify EQUI 5 as “limited use” under the Boiler MACT. The limit meets the requirements of being a federally enforceable capacity factor of 10% or less.

PM ≤ 0.60 lbs/MMBtu Opacity ≤ 20% with exceptions (Minn. R. 7011.0510)

None Compliance with these limits is expected due to the allowable fuels and boiler design. The PTE from this unit is 0.00745 lbs/MMBtu.

Fuel restricted to natural gas only (Minn. R. 7007.0800, subp. 2)

Daily fuel use records The boiler is designed to burn natural gas only. While the high school boilers are rarely used, fuel use must be recorded each day of operation.


Heat Input ≤ 31536 MMBtu/yr (Title I Condition NESHAP)


This capacity factor is needed to classify EQUI 6 as “limited use” under the Boiler MACT. The limit meets the requirements of being a federally enforceable capacity factor of 10% or less.

PM ≤ 0.60 lbs/MMBtu Opacity ≤ 20% with exceptions (Minn. R. 7011.0510)

None Compliance with these limits is expected due to the allowable fuels and boiler design. The PTE from this unit is 0.00745 lbs/MMBtu.

Fuel restricted to natural gas only (Minn. R. 7007.0800, subp. 2)

Daily fuel use records The boiler is designed to burn natural gas only. While the high school boilers are rarely used, fuel use must be recorded each day of operation.


Filterable PM ≤ 0.037 lb/MMBtu heat input (NESHAP Limit)

COMS, performance testing

EQUI 19 monitors the opacity of EQUI 7. CMS must be operated at all times, including startup and shutdown. Operating load or steam generation data must be collected every 15 minutes.

Hydrochloric Acid ≤ 0.022 lb/MMBtu heat input (NESHAP Limit)

Performance testing, fuel analyses

Annual HCl performance tests are required following the initial test. The Permittee must establish the maximum chlorine fuel input during the initial fuel analysis.

Mercury ≤ 5.70×10-6

lb/MMBtu heat input (NESHAP Limit)

Performance testing, fuel analyses

Annual Mercury performance tests are required following the initial test. The Permittee must establish the maximum fuel input during the initial fuel analysis.


CO CEMS, O2 CEMS




PM ≤ 0.025 lbs/MMBtu PM10 ≤ 0.025 lbs/MMBtu CO ≤ 0.58 lbs/MMBtu (8-hour block average) NOX ≤ 0.15 lbs/MMBtu (30-day rolling average) (Title I BACT Limits)

Performance testing for PM and PM10; CO CEMS; NOX CEMS Control equipment O&M

The Permittee is required to operate and maintain particulate matter and NOX control equipment any time the emission unit is in operation and use CEMS for CO and NOX. These requirements, in addition to the performance testing for PM and PM10 required for this emission unit is sufficient to have a reasonable assurance of compliance.




PM ≤ 0.03 lbs/MMBtu (3-hour average) NOX ≤ 0.20 lbs/MMBtu (30-day rolling average) Opacity ≤ 20% with exceptions (NSPS Limits)

Performance testing for PM; Control equipment O&M; NOX CEMS; COMS

The Permittee is required to operate and maintain particulate matter and NOX control equipment any time the emission unit is in operation, use CEMS for NOX, and use COMS to measure opacity. These requirements, in addition to the performance testing for PM required for this emission unit is sufficient to have a reasonable assurance of compliance.

Operating Hours ≤ 7,560 hours/year when combusting wood (12-month rolling sum) (Limit to avoid Environmental Review)

Recordkeeping: hours of operation; Fuel type/usage; Monthly calculations

The Permittee is required to keep records of hours of operation and fuel type/usage. Each month, this data must be used to calculate the hours of operation for the previous month and previous 12-month period. This includes both total operating hours and operating hours when combusting only wood or wood in combination with any other fuels. These requirements are sufficient to have a reasonable assurance of compliance.

NOX ≤ 69.00 lbs/hr (Title V Modeling Limit)

Control equipment O&M; NOX CEMS

The Permittee is required to operate and maintain NOX control equipment any time the emission unit is in operation and use Continuous Emissions Monitoring Systems (CEMS) for NOX. These requirements are sufficient to have a reasonable assurance of compliance.

Ammonia Slip ≤ 18.5 ppm (Minn. R. 7007.0800)

Performance testing for ammonia slip; Feed rate monitoring & recordkeeping

The Permittee is required to monitor and record the urea feed rate. These requirements, in addition to the performance testing for ammonia slip required for this emission unit is sufficient to have a reasonable assurance of compliance.

*Location of the requirement in the permit (e.g., EQUI, STRU, etc.).

3.6 Insignificant activities

Hibbing Public Utilities Commission has several operations which are classified as insignificant activities under the MPCA’s permitting rules. These are listed in Appendix A to the permit. No additional insignificant activities are included in this modification. The permit is required to include periodic monitoring for all emissions units, including insignificant activities, per EPA guidance. The insignificant activities at this Facility are only subject to general applicable requirements. Using the criteria outlined earlier in this TSD, the following table documents the justification why no additional periodic monitoring is necessary for the insignificant activities affected by this modification. See Attachment 1 of this TSD for PTE information for the insignificant activities.

Table 6. Insignificant activities

Insignificant activity General applicable emission limit Discussion

Open tumblers with a batch capacity of 1,000 pounds or less

PM, variable depending on airflow Opacity <= 20% (Minn. R. 7011.0710/0715)

HPUC operates a bead blasting operation.

For these units, based on EPA published emissions factors, it is highly unlikely that they could violate the applicable requirement. In addition, these units are vented inside a building, so testing for PM or opacity is not feasible.


Insignificant activity General applicable emission limit Discussion

Brazing, soldering or welding equipment


HPUC operates four welders.

For these units, based on EPA published emissions factors, it is highly unlikely that they could violate the applicable requirement. In addition, these units are typically operated and vented inside a building, so testing for PM or opacity is not feasible.

Individual units with potential emissions less than 2000 lb/year of certain pollutants

None: Prevent particulates from becoming airborne (Minn. R. 7011.0150 Minn. R. 7011.1110)

HPUC has coal handling operations including coal unloading (formerly identified as FS 001, uncontrolled PM = 0.0083 tpy) and coal pit dumping (formerly identified as FS 005, uncontrolled PM = 0.033 tpy).

For these activities, there is no applicable limit that needs to be met, just a general requirement to take reasonable precautions to prevent the discharge of visible fugitive dust emissions.

Infrequent use of spray paint equipment for routine housekeeping or plant upkeep activities not associated with primary production processes at the stationary source


HPUC uses aerosol paints for plant maintenance.

While spray equipment will have the potential to emit particulate matter, these particular activities are those not associated with production, so they would be infrequent and usually occur outdoors. Testing or monitoring for PM or opacity is not feasible.

Individual units with potential or actual emissions meeting the criteria in Minn. R. 7007.1300, subp. 4(A)-(D)

None: Prevent particulates from becoming airborne Minn. R. 7011.0150 Minn. R. 7011.1110 Minn. R. 7011.0710/0715

HPUC has a reserve coal pile (actual emissions based on highest throughput 2000 – 2009 = 0.013 tpy PM) and two cooling towers, the east cooling tower (formerly identified as EU014, potential PM = 2.05 lb/hr), and the west cooling tower (formerly identified as EU014, potential PM = 2.05 lb/hr).

For the reserve coal pile, there is no applicable limit that needs to be met, just a general requirement to take reasonable precautions to prevent the discharge of visible fugitive dust emissions. For the cooling towers, based on EPA published emissions factors, it is highly unlikely that they could violate the applicable requirement. In addition, testing for PM or opacity is not feasible.

Equipment venting PM/ PM10 inside a building, provided that emissions from the equipment are: a). filtered through an air cleaning system; and b). vented inside of the building 100% of the time


HPUC uses VOC-containing cleaning solvent facility wide.

For these units, based on EPA published emissions factors, it is highly unlikely that they could violate the applicable requirement. In addition, these activities are typically performed and vented inside a building, so testing for PM or opacity is not feasible.

3.7 Permit organization

In general, the permit meets the MPCA Guidance for ordering and grouping of requirements. One area where this permit deviates slightly from guidance is in the use of appendices. While appendices are fully enforceable parts of the permit, in general, any requirement that the MPCA thinks should be electronically tracked (e.g., limits, submittals, etc.), should be in Sections 5 and 6 of the permit. The main reason is that the appendices are word


processing sections and are not part of the electronic tracking system. Violation of the appendices can be enforced, but the computer system will not automatically generate the necessary enforcement notices or documents. Staff must generate these.

Appendix A is not used in this permit. Appendix B contains a listing of the facility’s insignificant activities and their applicable requirements. Appendix C contains the modeling input parameters used for Wood-Fired Boiler installation project. It also contains the predicted impacts and modeled concentrations for the standards in effect

at the time modeling was performed for NO2, CO, and PM10. Appendix C contains the modeling input parameters used for the 1-hour NO2 and SO2 national ambient air quality standards demonstration. It also contains the predicted impacts and modeled concentrations for NO2 and SO2 in comparison to these standards.

Another area that deviates from the guidance is in the use of groups where the requirements in the group apply to the members of the group individually. This was done in order to shorten the permit and where no testing or tracking specific to a unit is in the permit.

3.8 Comments received

Public Notice Period: [start date] – [end date] EPA Review Period: [start date] – [end date]

Comments were [not] received from the public during the public notice period. [The comments received did [not] include adverse comments on any applicable requirements of the permit. Changes to the permit were [not] made as a result of the comments.]

4 Permit fee assessment Attachment 3 to this TSD contains the MPCA’s assessment of Application and Additional Points used to

determine the permit application fee for this permit action as required by Minn. R. 7002.0019. The action

includes the incorporation of one NESHAP subp. DDDDD (10 pts.) and a limit to avoid an NSR major modification

(10 pts.). No other additional points apply to this permit action.

5 Conclusion

Based on the information provided by Hibbing Public Utilities Commission the MPCA has reasonable assurance that the proposed operation of the emission facility, as described in the Air Emission Permit No. 13700027-010 and this TSD, will not cause or contribute to a violation of applicable federal regulations and Minnesota Rules.

Staff Members on Permit Team: Eric Sulita (permit engineer)

Steve Palzkill (compliance) Amrill Okonkwo (peer reviewer) Beckie Olson (permit writing assistant) Laurie O’Brien (administrative support)

TEMPO360 Activities: Permit Change - Major Attachments: 1. PTE summary and emissions increase calculation spreadsheets 2. Points calculator

Attachment 1. PTE summary and emissions increase calculation spreadsheets

Project: Hibbing Public Utility Prepared: NEESubject: Potential to Emit Calculations Reviewed: ARDTask: Limited Emissions Totals For Entire Facility Date: July 2015

Emission Unit Boiler 1A Boiler 2A Boiler 3A Coal Ash Silo

HS Boiler 1

HS Boiler 2

Wood Boiler with Gas Burner

Enclosed Wood

Unloading Area

Wood Conveyor System

Wood Transfer/Metering

Bin

East and West Cooling Towers

Haul Roads

Coal Ash Loadout

Wood Ash

LoadoutCoal Unloading Coal Pit

DumpingReserve Coal Pile

Identification EU001 EU002 EU003 EU004 EU005 EU006 EU007 EU008 EU010 EU011

each tower is an IA source previously

identified collectively as EU014

FS002 FS003 FS004

IA source previously

identified as FS001

IA source previously

identified as FS005

IA Source

Pollutant TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPYNOX 489.74 489.74 562.29 --- 15.46 15.46 130.63 --- --- --- --- --- --- --- --- --- --- 1,703.30 1,703.30 0.00CO 278.26 278.26 319.48 --- 12.99 12.99 504.25 --- --- --- --- --- --- --- --- --- --- 1,406.22 1,406.22 0.00

VOC 5.10 5.10 4.16 --- 0.85 0.85 14.78 --- --- --- --- --- --- --- --- --- --- 30.84 29.88 0.97PM 567.65 567.65 651.74 30.11 1.17 1.17 21.74 2.63 0.26 0.14 17.98 0.36 0.01 0.0021 0.04 0.03 0.01 1,862.70 1,862.70 0.00

PM10 70.01 70.01 139.04 0.20 1.17 1.17 21.74 2.63 0.26 0.14 13.66 0.07 0.01 0.0010 0.02 0.02 0.00 320.15 320.15 0.00PM2.5 20.03 20.03 23.00 0.20 1.17 1.17 21.74 2.63 0.26 0.14 13.66 0.02 0.000 0.0002 0.003 0.002 0.001 104.07 104.07 0.00SO2 851.47 851.47 977.62 --- 0.09 0.09 21.74 --- --- --- --- --- --- --- --- --- --- 2,702.48 2,702.48 0.00Lead 0.02 0.02 0.03 --- 0.00 0.00 0.03 --- --- --- --- --- --- --- --- --- --- 0.10 0.10 0.00CO2e 204,183 204,183 234,432 --- 18,459 18,459 182,136 --- --- --- --- --- --- --- --- --- --- 861,851.01 861,851.01 0.00

TPY - Tons per YearIA - Insignificant ActivitySome of the emissions that are included in this table are the same as they are currently permitted. Changes in emissions are due to proposed process changes.

Proposed Facility PTE

Existing Facility

Permitted PTE

Change in Facility PTE

Project: Hibbing Public Utility Prepared: NEESubject: Potential to Emit Calculations Reviewed: ARDTask: Proposed Total Emissions of Speciated Organic Compounds and Metals Date: June 2015

Boiler #1 (EU001)

Boiler #2 (EU002)

Boiler #3 (EU003)

HS Boiler 1 (EU005)

HS Boiler 2 (EU006)

Wood Boiler

(EU007)

Total Facility

Pollutants EPA Pollutant Type CAS # TPY TPY TPY TPY TPY TPY TPY

Total HAPs --- --- 7.75E+01 7.75E+01 8.77E+01 2.92E-01 2.92E-01 2.49E+01 2.68E+02Ammonia 6 not classified 7664417 2.97E+00 2.97E+00 1.26E+00 4.95E-01 4.95E-01 3.04E+01 3.86E+01Benzene HAP 71432 7.23E-02 7.23E-02 8.31E-02 3.25E-04 3.25E-04 6.17E-01 8.46E-01

Hydrogen Fluoride HAP 7664393 8.35E+00 8.35E+00 9.58E+00 --- --- 1.39E+00 2.77E+01Hydrogen Chloride7 HAP 7647010 6.68E+01 6.68E+01 7.67E+01 --- --- 1.65E+01 2.27E+02

Mercury HAP 7439976 4.62E-03 4.62E-03 5.30E-03 4.02E-05 4.02E-05 3.04E-03 1.77E-021,1,1-Trichloroethane HAP 71556 1.11E-03 1.11E-03 1.28E-03 --- --- 2.70E-02 3.05E-02

1,2-Dichloroethane (ethyldene dichloride) HAP 107062 --- --- --- --- --- 2.52E-02 2.52E-021,2-Dichloropropane (propylene dichloride) HAP 78875 --- --- --- --- --- 2.87E-02 2.87E-02

2,3,7,8-TCDD HAP (POM) 1746016 7.96E-10 7.96E-10 9.14E-10 --- --- 9.22E-09 1.17E-082,3,7,8-TCDF HAP (POM) 51207319 2.84E-09 2.84E-09 3.26E-09 --- --- 4.39E-08 5.28E-08

2,4,6-Trichlorophenol HAP 88062 --- --- --- --- --- 9.91E-06 9.91E-062,4-Dinitrophenol HAP 51285 --- --- --- --- --- 8.11E-05 8.11E-05

2,4-Dinitrotoluene HAP 121142 1.56E-05 1.56E-05 1.79E-05 --- --- --- 4.91E-052-Chloroacetophenone HAP 532274 3.90E-04 3.90E-04 4.47E-04 --- --- --- 1.23E-03

2-Methylnaphthalene HAP (POM) 91576 2.23E-05 2.23E-05 9.28E-06 3.71E-06 3.71E-06 1.39E-04 2.00E-043-Methylchloranthrene HAP (POM) 56495 1.67E-06 1.67E-06 6.96E-07 2.78E-07 2.78E-07 6.96E-07 5.29E-06

5-Methyl chrysene HAP (POM) 3697243 1.22E-06 1.22E-06 1.41E-06 --- --- --- 3.85E-067,12-Dimethylbenz(a)anthracene HAP (POM) 57976 1.48E-05 1.48E-05 6.18E-06 2.47E-06 2.47E-06 6.18E-06 4.70E-05

4-Nitrophenol HAP 100027 --- --- --- --- --- 1.49E-04 1.49E-04Acenaphthene HAP (POM) 83329 2.84E-05 2.84E-05 3.26E-05 2.78E-07 2.78E-07 5.47E-06 9.54E-05

Acenaphthylene HAP (POM) 208968 1.39E-05 1.39E-05 1.60E-05 2.78E-07 2.78E-07 1.11E-03 1.16E-03Acetaldehyde HAP 75070 3.17E-02 3.17E-02 3.64E-02 --- --- 2.03E-01 3.03E-01

Acetophenone HAP 98862 8.35E-04 8.35E-04 9.58E-04 --- --- 2.78E-06 2.63E-03Acrolein HAP 107028 1.61E-02 1.61E-02 1.85E-02 --- --- 3.79E-02 8.87E-02

Anthracene HAP (POM) 120127 1.17E-05 1.17E-05 1.34E-05 3.71E-07 3.71E-07 3.63E-05 7.38E-05Antimony HAP 7440360 1.00E-03 1.00E-03 1.15E-03 --- --- 1.02E-02 1.33E-02Arsenic HAP 7440382 2.28E-02 2.28E-02 2.62E-02 3.09E-05 3.09E-05 2.83E-02 1.00E-01Barium 8 not classified 7440393 4.08E-03 4.08E-03 1.70E-03 6.80E-04 6.80E-04 1.48E-01 1.59E-01

Benzo(a)anthracene HAP (POM) 56553 4.45E-06 4.45E-06 5.11E-06 2.78E-07 2.78E-07 5.65E-05 7.11E-05Benzo(a)pyrene HAP (POM) 50328 2.11E-06 2.11E-06 2.43E-06 1.86E-07 1.86E-07 2.26E-03 2.27E-03

Benzo(b)fluoranthene HAP (POM) 205992 1.67E-06 1.67E-06 6.96E-07 2.78E-07 2.78E-07 8.69E-05 9.15E-05Benzo(g,h,i)perylene HAP (POM) 191242 1.50E-06 1.50E-06 1.73E-06 1.86E-07 1.86E-07 8.09E-05 8.60E-05Benzo(k)fluoranthene HAP (POM) 207089 6.12E-06 6.12E-06 7.03E-06 2.78E-07 2.78E-07 3.13E-05 5.11E-05

Benzyl chloride HAP 100447 3.90E-02 3.90E-02 4.47E-02 --- --- --- 1.23E-01Beryllium HAP 7440417 1.17E-03 1.17E-03 1.34E-03 1.86E-06 1.86E-06 1.55E-03 5.23E-03Biphenyl HAP (POM) 92524 9.46E-05 9.46E-05 1.09E-04 --- --- --- 2.98E-04

Bis(2-ethylhexyl)phthalate (DEHP) HAP 117817 4.06E-03 4.06E-03 4.66E-03 --- --- 4.09E-05 1.28E-02Bromoform HAP 75252 2.17E-03 2.17E-03 2.49E-03 --- --- --- 6.83E-03

Bromomethane HAP 74839 --- --- --- --- --- 1.30E-02 1.30E-02Butane not classified 106978 1.95E+00 1.95E+00 8.12E-01 3.25E-01 3.25E-01 8.12E-01 6.17E+00

Cadmium HAP 7440439 2.84E-03 2.84E-03 3.26E-03 1.70E-04 1.70E-04 --- 9.28E-03Carbon disulfide HAP 75150 7.23E-03 7.23E-03 8.31E-03 --- --- --- 2.28E-02

Carbon Tetrachloride HAP 56235 --- --- --- --- --- 3.91E-02 3.91E-02Chlorine HAP 7782505 --- --- --- --- --- 6.87E-01 6.87E-01

Chlorobenzene HAP 108907 1.22E-03 1.22E-03 1.41E-03 --- --- 2.87E-02 3.25E-02Chloroform HAP 67663 3.28E-03 3.28E-03 3.77E-03 --- --- 2.43E-02 3.47E-02Chromium HAP 7440473 1.45E-02 1.45E-02 1.66E-02 2.16E-04 2.16E-04 1.44E-03 4.74E-02

Chromium (VI) HAP 18540292 4.40E-03 4.40E-03 5.05E-03 --- --- 1.42E-03 1.53E-02Chrysene HAP (POM) 218019 5.57E-06 5.57E-06 6.39E-06 2.78E-07 2.78E-07 2.31E-06 2.04E-05Cobalt HAP 7440484 5.57E-03 5.57E-03 6.39E-03 1.30E-05 1.30E-05 3.08E-04 1.79E-02Copper not classified 7440508 7.88E-04 7.88E-04 3.29E-04 1.31E-04 1.31E-04 4.26E-02 4.48E-02

Cumene HAP 98828 2.95E-04 2.95E-04 3.39E-04 --- --- --- 9.29E-04Cyanide HAP 57125 1.39E-01 1.39E-01 1.60E-01 --- --- --- 4.38E-01

Dibenzo(a,h)anthracene HAP (POM) 53703 1.11E-06 1.11E-06 4.64E-07 1.86E-07 1.86E-07 7.91E-06 1.10E-05Dichlorobenzene HAP 25321226 1.11E-03 1.11E-03 4.64E-04 1.86E-04 1.86E-04 4.64E-04 3.52E-03

Dichloromethane (methylene chloride) HAP 75092 --- --- --- --- --- 2.52E-01 2.52E-01Dimethyl sulfate HAP 77781 2.67E-03 2.67E-03 3.07E-03 --- --- --- 8.41E-03

Ethane not classified 74840 2.88E+00 2.88E+00 1.20E+00 4.79E-01 4.79E-01 1.20E+00 9.11E+00Ethyl benzene HAP 100414 5.23E-03 5.23E-03 6.01E-03 --- --- 2.70E-02 4.34E-02Ethyl chloride HAP 75003 2.34E-03 2.34E-03 2.68E-03 --- --- --- 7.36E-03

Ethylene dibromide HAP 106934 6.68E-05 6.68E-05 7.67E-05 --- --- --- 2.10E-04Ethylene dichloride HAP 107062 2.23E-03 2.23E-03 2.56E-03 --- --- --- 7.01E-03

Fluoranthene HAP (POM) 206440 3.95E-05 3.95E-05 4.54E-05 --- --- 1.39E-03 1.52E-03Fluorene HAP (POM) 86737 5.06E-05 5.06E-05 5.81E-05 4.33E-07 4.33E-07 2.96E-03 3.12E-03

Formaldehyde HAP 50000 6.96E-02 6.96E-02 3.88E-02 1.16E-02 1.16E-02 1.22E+00 1.42E+00

Emission Units

Boiler #1 (EU001)

Boiler #2 (EU002)

Boiler #3 (EU003)

HS Boiler 1 (EU005)

HS Boiler 2 (EU006)

Wood Boiler

(EU007)

Total Facility

Pollutants EPA Pollutant Type CAS # TPY TPY TPY TPY TPY TPY TPY

Emission Units

Hexane HAP 110543 1.67E+00 1.67E+00 6.98E-01 2.78E-01 2.78E-01 6.96E-01 5.29E+00Indeno(1,2,3-cd)pyrene HAP (POM) 193395 3.39E-06 3.39E-06 3.90E-06 2.78E-07 2.78E-07 7.56E-05 8.69E-05

Isophorone HAP 78591 3.23E-02 3.23E-02 3.71E-02 --- --- --- 1.02E-01Magnesium not classified 7439954 6.12E-01 6.12E-01 7.03E-01 --- --- --- 1.93E+00Manganese HAP 7439965 2.73E-02 2.73E-02 3.13E-02 5.87E-05 5.87E-05 1.13E+00 1.22E+00

Methyl bromide HAP 74839 8.90E-03 8.90E-03 1.02E-02 --- --- --- 2.80E-02Methyl chloride HAP 74873 2.95E-02 2.95E-02 3.39E-02 --- --- 2.00E-02 1.13E-01

Methyl ethyl ketone (MEK) not classified 78933 2.17E-02 2.17E-02 2.49E-02 --- --- --- 6.83E-02Methyl hydrazine HAP 60344 9.46E-03 9.46E-03 1.09E-02 --- --- --- 2.98E-02

Methyl methacrylate HAP 80626 1.11E-03 1.11E-03 1.28E-03 --- --- --- 3.50E-03Methyl tert butyl ether HAP 1634044 1.95E-03 1.95E-03 2.24E-03 --- --- --- 6.13E-03Methylene chloride HAP 75092 1.61E-02 1.61E-02 1.85E-02 --- --- --- 5.08E-02

Molybdenum not classified 7439987 1.02E-03 1.02E-03 4.25E-04 1.70E-04 1.70E-04 1.83E-03 4.63E-03Naphthalene HAP (POM) 91203 7.23E-04 7.23E-04 8.31E-04 9.43E-05 9.43E-05 5.93E-02 6.18E-02

Nickel HAP 7440020 1.56E-02 1.56E-02 1.79E-02 3.25E-04 3.25E-04 2.20E-03 5.19E-02Pentane not classified 109660 2.41E+00 2.41E+00 1.00E+00 4.02E-01 4.02E-01 1.00E+00 7.64E+00

Phenanthrene HAP (POM) 85018 1.50E-04 1.50E-04 1.73E-04 2.63E-06 2.63E-06 1.18E-03 1.66E-03Phenol HAP 108952 8.90E-04 8.90E-04 1.02E-03 --- --- 1.09E-02 1.37E-02

Phosphorus HAP 7723140 --- --- --- --- --- 1.68E-02 1.68E-02Propane not classified 74986 1.48E+00 1.48E+00 6.18E-01 2.47E-01 2.47E-01 6.18E-01 4.70E+00

Propionaldehyde HAP 123386 2.11E-02 2.11E-02 2.43E-02 --- --- 5.30E-02 1.20E-01Pyrene HAP (POM) 129000 1.84E-05 1.84E-05 2.11E-05 7.73E-07 7.73E-07 --- 5.94E-05

Selenium HAP 7782492 7.23E-02 7.23E-02 8.31E-02 3.71E-06 3.71E-06 2.12E-03 2.30E-01Styrene HAP 100425 1.39E-03 1.39E-03 1.60E-03 --- --- 1.65E+00 1.66E+00

Tetrachloroethylene HAP 127184 2.39E-03 2.39E-03 2.75E-03 --- --- --- 7.53E-03Toluene HAP 108883 1.34E-02 1.34E-02 1.53E-02 5.26E-04 5.26E-04 1.85E-02 6.16E-02

Total HpCDD HAP (POM) 37871004 4.64E-09 4.64E-09 5.33E-09 --- --- --- 1.46E-08Total HpCDF HAP (POM) 38998753 4.27E-09 4.27E-09 4.91E-09 --- --- --- 1.35E-08Total HxCDD HAP (POM) 34465468 1.60E-09 1.60E-09 1.83E-09 --- --- --- 5.03E-09Total HxCDF HAP (POM) 55684941 1.07E-08 1.07E-08 1.23E-08 --- --- --- 3.36E-08Total OCDD HAP (POM) 3268879 2.32E-08 2.32E-08 2.66E-08 --- --- --- 7.29E-08Total OCDF HAP (POM) 39001020 3.69E-09 3.69E-09 4.24E-09 --- --- --- 1.16E-08

Total PeCDD HAP (POM) 36088229 2.49E-09 2.49E-09 2.86E-09 --- --- --- 7.83E-09Total PeCDF HAP (POM) 30402154 1.96E-08 1.96E-08 2.26E-08 --- --- --- 6.18E-08Total TCDD HAP (POM) 41903575 5.16E-09 5.16E-09 5.93E-09 --- --- --- 1.63E-08Total TCDF HAP (POM) 30402143 2.25E-08 2.25E-08 2.58E-08 --- --- --- 7.08E-08Vanadium not classified 7440622 2.13E-03 2.13E-03 8.89E-04 3.56E-04 3.56E-04 --- 5.87E-03

Vinyl acetate HAP 108054 4.23E-04 4.23E-04 4.86E-04 --- --- --- 1.33E-03Vinyl Chloride HAP 75014 --- --- --- --- --- 1.56E-02 1.56E-02

Xylenes HAP 1330207 2.06E-03 2.06E-03 2.36E-03 --- --- 2.17E-02 2.82E-02Zinc not classified 7440666 2.69E-02 2.69E-02 1.12E-02 4.48E-03 4.48E-03 3.65E-01 4.39E-01

Project: Hibbing Public Utilities Prepared: NEESubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler #3A (EU003) Date: June 2015

Revised: July 2015

Boiler 3A

Assumptions:

Nat. GasAP-421

Nat. Gas 40 CFR Part 982,3

CoalAP-424

Coal 40 CFR Part 982,3

Permitted to combust sub-bituminous and bituminous coal, natural gas, and oily rags (initial firing) lb/MMBtu lb/MMscf lb/MMBtu lb/ton lb/MMBtu lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY

Rated Capacity, MMBtu/hr 248 Particulate Matter criteria NA 95% 0.60 7.60 --- 12 --- 148.80 651.74 94.80 415.22 0.67 2.94 95.47 418.16 148.80 651.74 Coal Only 148.80 651.74Heating Value of Coal (from Permit), MMBtu/ton 17 Particulate Matter <10 microns criteria NA 95% 0.128 7.60 --- 7.8 --- 31.74 139.04 20.22 88.58 0.67 2.94 20.89 91.52 31.74 139.04 Coal Only 31.74 139.04Natural Gas Burner Capacity, MMBtu/hr 90 Particulate Matter <2.5 microns criteria NA 90% --- 7.60 --- 0.36 --- 5.25 23.00 3.35 14.65 0.67 2.94 4.02 17.59 5.25 23.00 Coal Only 5.25 23.00Heating Value of Natural Gas (from permit), Btu/scf 1,020 Sulfur Dioxide criteria NA NA 0.90 0.60 --- 38 --- 223.20 977.62 142.20 622.84 0.05 0.23 142.25 623.07 223.20 977.62 Coal Only 223.20 977.62

Max Hourly Fuel Rate for Natural Gas, 106 scf/hr 0.09 Nitrogen Oxides criteria NA --- --- 100 --- 8.8 --- 128.38 562.29 81.79 358.23 8.82 38.65 90.61 396.88 128.38 562.29 Coal Only 128.38 562.29Maximum Coal Throughput, tons/yr 127,793 Carbon Monoxide criteria NA --- --- 84 --- 5 --- 72.94 319.48 46.47 203.54 7.41 32.46 53.88 236.00 72.94 319.48 Coal Only 72.94 319.48Annual Operating Hours 8,760 Volatile Organic Compounds criteria NA --- --- 5.50 --- 0.05 --- 0.73 3.19 0.46 2.04 0.49 2.13 0.95 4.16 0.95 4.16 Combined 0.95 4.16Coal Limit, tons/year NA Lead criteria 7439921 --- --- 5.00E-04 --- 4.20E-04 --- 6.13E-03 2.68E-02 0.00 0.02 4.41E-05 1.93E-04 0.00 0.02 0.01 0.03 Coal Only 0.01 0.03

CO2 GHG NA --- --- --- 116.94 --- 214.16 53,112.34 232,632.07 33,837.70 148,209.14 10,524.98 46,099.42 44,362.69 194,308.56 53,112.34 232,632.07 Coal Only 53,112.34 232,632.07Conversion Factors: CH4 GHG NA --- --- --- 0.002 --- 0.024 6.01 26.33 3.83 16.78 0.20 0.87 4.03 17.65 6.01 26.33 Coal Only 6.01 26.33

lb/ton 2,000 N2O GHG NA --- --- --- 0.0002 --- 0.0035 0.87 3.83 0.56 2.44 0.02 0.09 0.58 2.53 0.87 3.83 Coal Only 0.87 3.83lb/kg 2.204 CO2e

5 GHG NA --- --- --- 117.07 --- 215.82 53,523.27 234,431.93 34,099.50 149,355.83 10,535.85 46,147.03 44,635.36 195,502.86 53,523.27 234,431.93 Coal Only 53,523.27 234,431.93CO2 to CO2e 1 Ammonia 6 not classified 7664417 --- --- 3.20E+00 --- 5.65E-04 --- 8.24E-03 3.61E-02 0.01 0.02 2.82E-01 1.24E+00 0.29 1.26 0.29 1.26 Combined 0.29 1.26

CH4 to CO2e 25 Benzene HAP 71432 --- --- 2.10E-03 --- 1.30E-03 --- 1.90E-02 8.31E-02 0.01 0.05 1.85E-04 8.12E-04 0.01 0.05 0.02 0.08 Coal Only 0.02 0.08N2O to CO2e 298 Hydrogen Fluoride HAP 7664393 --- --- --- --- 0.15 --- 2.19 9.58E+00 1.39 6.11 --- --- 1.39 6.11 2.19 9.58 Coal Only 2.19 9.58Btu/MMBtu 1,000,000 Hydrogen Chloride7 HAP 7647010 --- --- --- --- 1.20 --- 17.51 76.68 11.15 48.85 --- --- 11.15 48.85 17.51 76.68 Coal Only 17.51 76.68hr/yr 8,760 Mercury HAP 7439976 --- --- 2.60E-04 --- 8.30E-05 --- 1.21E-03 5.30E-03 7.71E-04 3.38E-03 2.29E-05 1.00E-04 7.94E-04 3.48E-03 1.21E-03 5.30E-03 Coal Only 1.21E-03 5.30E-03min/hr 60 1,1,1-Trichloroethane HAP 71556 --- --- --- --- 2.00E-05 --- 2.92E-04 1.28E-03 1.86E-04 8.14E-04 --- --- 1.86E-04 8.14E-04 2.92E-04 1.28E-03 Coal Only 2.92E-04 1.28E-03

2,3,7,8-TCDD HAP (POM) 1746016 --- --- --- --- 1.43E-11 --- 2.09E-10 9.14E-10 1.33E-10 5.82E-10 --- --- 1.33E-10 5.82E-10 2.09E-10 9.14E-10 Coal Only 2.09E-10 9.14E-102,3,7,8-TCDF HAP (POM) 51207319 --- --- --- --- 5.10E-11 --- 7.44E-10 3.26E-09 4.74E-10 2.08E-09 --- --- 4.74E-10 2.08E-09 7.44E-10 3.26E-09 Coal Only 7.44E-10 3.26E-092,4-Dinitrotoluene HAP 121142 --- --- --- --- 2.80E-07 --- 4.08E-06 1.79E-05 2.60E-06 1.14E-05 --- --- 2.60E-06 1.14E-05 4.08E-06 1.79E-05 Coal Only 4.08E-06 1.79E-052-Chloroacetophenone HAP 532274 --- --- --- --- 7.00E-06 --- 1.02E-04 4.47E-04 6.51E-05 2.85E-04 --- --- 6.51E-05 2.85E-04 1.02E-04 4.47E-04 Coal Only 1.02E-04 4.47E-042-Methylnaphthalene HAP (POM) 91576 --- --- 2.40E-05 --- --- --- --- --- --- --- 2.12E-06 9.28E-06 2.12E-06 9.28E-06 2.12E-06 9.28E-06 Combined 2.12E-06 9.28E-063-Methylchloranthrene HAP (POM) 56495 --- --- 1.80E-06 --- --- --- --- --- --- --- 1.59E-07 6.96E-07 1.59E-07 6.96E-07 1.59E-07 6.96E-07 Combined 1.59E-07 6.96E-075-Methyl chrysene HAP (POM) 3697243 --- --- --- --- 2.20E-08 --- 3.21E-07 1.41E-06 2.04E-07 8.96E-07 --- --- 2.04E-07 8.96E-07 3.21E-07 1.41E-06 Coal Only 3.21E-07 1.41E-067,12-Dimethylbenz(a)anthracene HAP (POM) 57976 --- --- 1.60E-05 --- --- --- --- --- --- --- 1.41E-06 6.18E-06 1.41E-06 6.18E-06 1.41E-06 6.18E-06 Combined 1.41E-06 6.18E-06Acenaphthene HAP (POM) 83329 --- --- 1.80E-06 --- 5.10E-07 --- 7.44E-06 3.26E-05 4.74E-06 2.08E-05 1.59E-07 6.96E-07 4.90E-06 2.15E-05 7.44E-06 3.26E-05 Coal Only 7.44E-06 3.26E-05Acenaphthylene HAP (POM) 208968 --- --- 1.80E-06 --- 2.50E-07 --- 3.65E-06 1.60E-05 2.32E-06 1.02E-05 1.59E-07 6.96E-07 2.48E-06 1.09E-05 3.65E-06 1.60E-05 Coal Only 3.65E-06 1.60E-05Acetaldehyde HAP 75070 --- --- --- --- 5.70E-04 --- 8.32E-03 3.64E-02 5.30E-03 2.32E-02 --- --- 5.30E-03 2.32E-02 8.32E-03 3.64E-02 Coal Only 8.32E-03 3.64E-02Acetophenone HAP 98862 --- --- --- --- 1.50E-05 --- 2.19E-04 9.58E-04 1.39E-04 6.11E-04 --- --- 1.39E-04 6.11E-04 2.19E-04 9.58E-04 Coal Only 2.19E-04 9.58E-04Acrolein HAP 107028 --- --- --- --- 2.90E-04 --- 4.23E-03 1.85E-02 2.70E-03 1.18E-02 --- --- 2.70E-03 1.18E-02 4.23E-03 1.85E-02 Coal Only 4.23E-03 1.85E-02Anthracene HAP (POM) 120127 --- --- 2.40E-06 --- 2.10E-07 --- 3.06E-06 1.34E-05 1.95E-06 8.55E-06 2.12E-07 9.28E-07 2.16E-06 9.48E-06 3.06E-06 1.34E-05 Coal Only 3.06E-06 1.34E-05Antimony HAP 7440360 --- --- --- --- 1.80E-05 --- 2.63E-04 1.15E-03 1.67E-04 7.33E-04 --- --- 1.67E-04 7.33E-04 2.63E-04 1.15E-03 Coal Only 2.63E-04 1.15E-03Arsenic HAP 7440382 --- --- 2.00E-04 --- 4.10E-04 --- 5.98E-03 2.62E-02 3.81E-03 1.67E-02 1.76E-05 7.73E-05 3.83E-03 1.68E-02 5.98E-03 2.62E-02 Coal Only 5.98E-03 2.62E-02

Barium 8 not classified 7440393 --- --- 4.40E-03 --- --- --- --- --- --- --- 3.88E-04 1.70E-03 3.88E-04 1.70E-03 3.88E-04 1.70E-03 Combined 3.88E-04 1.70E-03

Benzo(a)anthracene HAP (POM) 56553 --- --- 1.80E-06 --- 8.00E-08 --- 1.17E-06 5.11E-06 7.44E-07 3.26E-06 1.59E-07 6.96E-07 9.02E-07 3.95E-06 1.17E-06 5.11E-06 Coal Only 1.17E-06 5.11E-06Benzo(a)pyrene HAP (POM) 50328 --- --- 1.20E-06 --- 3.80E-08 --- 5.54E-07 2.43E-06 3.53E-07 1.55E-06 1.06E-07 4.64E-07 4.59E-07 2.01E-06 5.54E-07 2.43E-06 Coal Only 5.54E-07 2.43E-06Benzo(b)fluoranthene HAP (POM) 205992 --- --- 1.80E-06 --- --- --- --- --- 0.00E+00 0.00E+00 1.59E-07 6.96E-07 1.59E-07 6.96E-07 1.59E-07 6.96E-07 Combined 1.59E-07 6.96E-07Benzo(g,h,i)perylene HAP (POM) 191242 --- --- 1.20E-06 --- 2.70E-08 --- 3.94E-07 1.73E-06 2.51E-07 1.10E-06 1.06E-07 4.64E-07 3.57E-07 1.56E-06 3.94E-07 1.73E-06 Coal Only 3.94E-07 1.73E-06Benzo(k)fluoranthene HAP (POM) 207089 --- --- 1.80E-06 --- 1.10E-07 --- 1.60E-06 7.03E-06 1.02E-06 4.48E-06 1.59E-07 6.96E-07 1.18E-06 5.17E-06 1.60E-06 7.03E-06 Coal Only 1.60E-06 7.03E-06Benzyl chloride HAP 100447 --- --- --- --- 7.00E-04 --- 1.02E-02 4.47E-02 6.51E-03 2.85E-02 --- --- 6.51E-03 2.85E-02 1.02E-02 4.47E-02 Coal Only 1.02E-02 4.47E-02Beryllium HAP 7440417 --- --- 1.20E-05 --- 2.10E-05 --- 3.06E-04 1.34E-03 1.95E-04 8.55E-04 1.06E-06 4.64E-06 1.96E-04 8.60E-04 3.06E-04 1.34E-03 Coal Only 3.06E-04 1.34E-03Biphenyl HAP (POM) 92524 --- --- --- --- 1.70E-06 --- 2.48E-05 1.09E-04 1.58E-05 6.92E-05 --- --- 1.58E-05 6.92E-05 2.48E-05 1.09E-04 Coal Only 2.48E-05 1.09E-04Bis(2-ethylhexyl)phthalate (DEHP) HAP 117817 --- --- --- --- 7.30E-05 --- 1.06E-03 4.66E-03 6.78E-04 2.97E-03 --- --- 6.78E-04 2.97E-03 1.06E-03 4.66E-03 Coal Only 1.06E-03 4.66E-03Bromoform HAP 75252 --- --- --- --- 3.90E-05 --- 5.69E-04 2.49E-03 3.62E-04 1.59E-03 --- --- 3.62E-04 1.59E-03 5.69E-04 2.49E-03 Coal Only 5.69E-04 2.49E-03Butane not classified 106978 --- --- 2.10E+00 --- --- --- --- --- --- --- 1.85E-01 8.12E-01 1.85E-01 8.12E-01 1.85E-01 8.12E-01 Combined 1.85E-01 8.12E-01

Cadmium HAP 7440439 --- --- 1.10E-03 --- 5.10E-05 --- 7.44E-04 3.26E-03 4.74E-04 2.08E-03 9.71E-05 4.25E-04 5.71E-04 2.50E-03 7.44E-04 3.26E-03 Coal Only 7.44E-04 3.26E-03Carbon disulfide HAP 75150 --- --- --- --- 1.30E-04 --- 1.90E-03 8.31E-03 1.21E-03 5.29E-03 --- --- 1.21E-03 5.29E-03 1.90E-03 8.31E-03 Coal Only 1.90E-03 8.31E-03Chlorobenzene HAP 108907 --- --- --- --- 2.20E-05 --- 3.21E-04 1.41E-03 2.04E-04 8.96E-04 --- --- 2.04E-04 8.96E-04 3.21E-04 1.41E-03 Coal Only 3.21E-04 1.41E-03Chloroform HAP 67663 --- --- --- --- 5.90E-05 --- 8.61E-04 3.77E-03 5.48E-04 2.40E-03 --- --- 5.48E-04 2.40E-03 8.61E-04 3.77E-03 Coal Only 8.61E-04 3.77E-03Chromium HAP 7440473 --- --- 1.40E-03 --- 2.60E-04 --- 3.79E-03 1.66E-02 2.42E-03 1.06E-02 1.24E-04 5.41E-04 2.54E-03 1.11E-02 3.79E-03 1.66E-02 Coal Only 3.79E-03 1.66E-02Chromium (VI) HAP 18540292 --- --- --- --- 7.90E-05 --- 1.15E-03 5.05E-03 7.34E-04 3.22E-03 --- --- 7.34E-04 3.22E-03 1.15E-03 5.05E-03 Coal Only 1.15E-03 5.05E-03Chrysene HAP (POM) 218019 --- --- 1.80E-06 --- 1.00E-07 --- 1.46E-06 6.39E-06 9.29E-07 4.07E-06 1.59E-07 6.96E-07 1.09E-06 4.77E-06 1.46E-06 6.39E-06 Coal Only 1.46E-06 6.39E-06Cobalt HAP 7440484 --- --- 8.40E-05 --- 1.00E-04 --- 1.46E-03 6.39E-03 9.29E-04 4.07E-03 7.41E-06 3.25E-05 9.37E-04 4.10E-03 1.46E-03 6.39E-03 Coal Only 1.46E-03 6.39E-03Copper not classified 7440508 --- --- 8.50E-04 --- --- --- --- --- --- --- 7.50E-05 3.29E-04 7.50E-05 3.29E-04 7.50E-05 3.29E-04 Combined 7.50E-05 3.29E-04

Cumene HAP 98828 --- --- --- --- 5.30E-06 --- 7.73E-05 3.39E-04 4.93E-05 2.16E-04 --- --- 4.93E-05 2.16E-04 7.73E-05 3.39E-04 Coal Only 7.73E-05 3.39E-04Cyanide HAP 57125 --- --- --- --- 2.50E-03 --- 3.65E-02 1.60E-01 2.32E-02 1.02E-01 --- --- 2.32E-02 1.02E-01 3.65E-02 1.60E-01 Coal Only 3.65E-02 1.60E-01Dibenzo(a,h)anthracene HAP (POM) 53703 --- --- 1.20E-06 --- --- --- --- --- --- --- 1.06E-07 4.64E-07 1.06E-07 4.64E-07 1.06E-07 4.64E-07 Combined 1.06E-07 4.64E-07Dichlorobenzene HAP 25321226 --- --- 1.20E-03 --- --- --- --- --- --- --- 1.06E-04 4.64E-04 1.06E-04 4.64E-04 1.06E-04 4.64E-04 Combined 1.06E-04 4.64E-04Dimethyl sulfate HAP 77781 --- --- --- --- 4.80E-05 --- 7.00E-04 3.07E-03 4.46E-04 1.95E-03 --- --- 4.46E-04 1.95E-03 7.00E-04 3.07E-03 Coal Only 7.00E-04 3.07E-03

PTE with Natual Gas Burner and Coal Combustion

Coal @ 100% Capacity (248 MMBtu/Hr) Coal @ 158 MMBtu/Hr Nat. Gas @ 90 MMBtu/Hr

Coal at 158 MMBtu and Nat. Gas at 90 MMBtu10

Emission Factors Potential Emissions as Permitted Potential Emissions of Combined Fuels

Annual Worst-Case Fuel

TypeWorst-Case Operating

Scenario Fuel Pollutant EPA Pollutant

TypeCAS

NumberControl

Efficiency

Permit Limits

Nat. GasAP-421


CoalAP-424


lb/MMBtu lb/MMscf lb/MMBtu lb/ton lb/MMBtu lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY

Ethane not classified 74840 --- --- 3.10E+00 --- --- --- --- --- --- --- 2.74E-01 1.20E+00 2.74E-01 1.20E+00 2.74E-01 1.20E+00 Combined 2.74E-01 1.20E+00

Ethyl benzene HAP 100414 --- --- --- --- 9.40E-05 --- 1.37E-03 6.01E-03 8.74E-04 3.83E-03 --- --- 8.74E-04 3.83E-03 1.37E-03 6.01E-03 Coal Only 1.37E-03 6.01E-03Ethyl chloride HAP 75003 --- --- --- --- 4.20E-05 --- 6.13E-04 2.68E-03 3.90E-04 1.71E-03 --- --- 3.90E-04 1.71E-03 6.13E-04 2.68E-03 Coal Only 6.13E-04 2.68E-03Ethylene dibromide HAP 106934 --- --- --- --- 1.20E-06 --- 1.75E-05 7.67E-05 1.12E-05 4.88E-05 --- --- 1.12E-05 4.88E-05 1.75E-05 7.67E-05 Coal Only 1.75E-05 7.67E-05Ethylene dichloride HAP 107062 --- --- --- --- 4.00E-05 --- 5.84E-04 2.56E-03 3.72E-04 1.63E-03 --- --- 3.72E-04 1.63E-03 5.84E-04 2.56E-03 Coal Only 5.84E-04 2.56E-03Fluoranthene HAP (POM) 206440 --- --- 3.00E-06 --- 7.10E-07 --- 1.04E-05 4.54E-05 6.60E-06 2.89E-05 2.65E-07 1.16E-06 6.86E-06 3.01E-05 1.04E-05 4.54E-05 Coal Only 1.04E-05 4.54E-05Fluorene HAP (POM) 86737 --- --- 2.80E-06 --- 9.10E-07 --- 1.33E-05 5.81E-05 8.46E-06 3.70E-05 2.47E-07 1.08E-06 8.70E-06 3.81E-05 1.33E-05 5.81E-05 Coal Only 1.33E-05 5.81E-05Formaldehyde HAP 50000 --- --- 7.50E-02 --- 2.40E-04 --- 3.50E-03 1.53E-02 2.23E-03 9.77E-03 6.62E-03 2.90E-02 8.85E-03 3.88E-02 8.85E-03 3.88E-02 Combined 8.85E-03 3.88E-02Hexane HAP 110543 --- --- 1.80E+00 --- 6.70E-05 --- 9.77E-04 4.28E-03 6.23E-04 2.73E-03 1.59E-01 6.96E-01 1.59E-01 6.98E-01 1.59E-01 6.98E-01 Combined 1.59E-01 6.98E-01Indeno(1,2,3-cd)pyrene HAP (POM) 193395 --- --- 1.80E-06 --- 6.10E-08 --- 8.90E-07 3.90E-06 5.67E-07 2.48E-06 1.59E-07 6.96E-07 7.26E-07 3.18E-06 8.90E-07 3.90E-06 Coal Only 8.90E-07 3.90E-06Isophorone HAP 78591 --- --- --- --- 5.80E-04 --- 8.46E-03 3.71E-02 5.39E-03 2.36E-02 --- --- 5.39E-03 2.36E-02 8.46E-03 3.71E-02 Coal Only 8.46E-03 3.71E-02Magnesium not classified 7439954 --- --- --- --- 1.10E-02 --- 1.60E-01 7.03E-01 1.02E-01 4.48E-01 --- --- 1.02E-01 4.48E-01 1.60E-01 7.03E-01 Coal Only 1.60E-01 7.03E-01

Manganese HAP 7439965 --- --- 3.80E-04 --- 4.90E-04 --- 7.15E-03 3.13E-02 4.55E-03 1.99E-02 3.35E-05 1.47E-04 4.59E-03 2.01E-02 7.15E-03 3.13E-02 Coal Only 7.15E-03 3.13E-02Methyl bromide HAP 74839 --- --- --- --- 1.60E-04 --- 2.33E-03 1.02E-02 1.49E-03 6.51E-03 --- --- 1.49E-03 6.51E-03 2.33E-03 1.02E-02 Coal Only 2.33E-03 1.02E-02Methyl chloride HAP 74873 --- --- --- --- 5.30E-04 --- 7.73E-03 3.39E-02 4.93E-03 2.16E-02 --- --- 4.93E-03 2.16E-02 7.73E-03 3.39E-02 Coal Only 7.73E-03 3.39E-02Methyl ethyl ketone (MEK) not classified 78933 --- --- --- --- 3.90E-04 --- 5.69E-03 2.49E-02 3.62E-03 1.59E-02 --- --- 3.62E-03 1.59E-02 5.69E-03 2.49E-02 Coal Only 5.69E-03 2.49E-02

Methyl hydrazine HAP 60344 --- --- --- --- 1.70E-04 --- 2.48E-03 1.09E-02 1.58E-03 6.92E-03 --- --- 1.58E-03 6.92E-03 2.48E-03 1.09E-02 Coal Only 2.48E-03 1.09E-02Methyl methacrylate HAP 80626 --- --- --- --- 2.00E-05 --- 2.92E-04 1.28E-03 1.86E-04 8.14E-04 --- --- 1.86E-04 8.14E-04 2.92E-04 1.28E-03 Coal Only 2.92E-04 1.28E-03Methyl tert butyl ether HAP 1634044 --- --- --- --- 3.50E-05 --- 5.11E-04 2.24E-03 3.25E-04 1.42E-03 --- --- 3.25E-04 1.42E-03 5.11E-04 2.24E-03 Coal Only 5.11E-04 2.24E-03Methylene chloride HAP 75092 --- --- --- --- 2.90E-04 --- 4.23E-03 1.85E-02 2.70E-03 1.18E-02 --- --- 2.70E-03 1.18E-02 4.23E-03 1.85E-02 Coal Only 4.23E-03 1.85E-02Molybdenum not classified 7439987 --- --- 1.10E-03 --- --- --- --- --- --- --- 9.71E-05 4.25E-04 9.71E-05 4.25E-04 9.71E-05 4.25E-04 Combined 9.71E-05 4.25E-04

Naphthalene HAP (POM) 91203 --- --- 6.10E-04 --- 1.30E-05 --- 1.90E-04 8.31E-04 1.21E-04 5.29E-04 5.38E-05 2.36E-04 1.75E-04 7.65E-04 1.90E-04 8.31E-04 Coal Only 1.90E-04 8.31E-04Nickel HAP 7440020 --- --- 2.10E-03 --- 2.80E-04 --- 4.08E-03 1.79E-02 2.60E-03 1.14E-02 1.85E-04 8.12E-04 2.79E-03 1.22E-02 4.08E-03 1.79E-02 Coal Only 4.08E-03 1.79E-02Pentane not classified 109660 --- --- 2.60E+00 --- --- --- --- --- --- --- 2.29E-01 1.00E+00 2.29E-01 1.00E+00 2.29E-01 1.00E+00 Combined 2.29E-01 1.00E+00

Phenanthrene HAP (POM) 85018 --- --- 1.70E-05 --- 2.70E-06 --- 3.94E-05 1.73E-04 2.51E-05 1.10E-04 1.50E-06 6.57E-06 2.66E-05 1.16E-04 3.94E-05 1.73E-04 Coal Only 3.94E-05 1.73E-04Phenol HAP 108952 --- --- --- --- 1.60E-05 --- 2.33E-04 1.02E-03 1.49E-04 6.51E-04 --- --- 1.49E-04 6.51E-04 2.33E-04 1.02E-03 Coal Only 2.33E-04 1.02E-03Propane not classified 74986 --- --- 1.60E+00 --- --- --- --- --- --- --- 1.41E-01 6.18E-01 1.41E-01 6.18E-01 1.41E-01 6.18E-01 Combined 1.41E-01 6.18E-01

Propionaldehyde HAP 123386 --- --- --- --- 3.80E-04 --- 5.54E-03 2.43E-02 3.53E-03 1.55E-02 --- --- 3.53E-03 1.55E-02 5.54E-03 2.43E-02 Coal Only 5.54E-03 2.43E-02Pyrene HAP (POM) 129000 --- --- 5.00E-06 --- 3.30E-07 --- 4.81E-06 2.11E-05 3.07E-06 1.34E-05 4.41E-07 1.93E-06 3.51E-06 1.54E-05 4.81E-06 2.11E-05 Coal Only 4.81E-06 2.11E-05Selenium HAP 7782492 --- --- 2.40E-05 --- 1.30E-03 --- 1.90E-02 8.31E-02 1.21E-02 5.29E-02 2.12E-06 9.28E-06 1.21E-02 5.29E-02 1.90E-02 8.31E-02 Coal Only 1.90E-02 8.31E-02Styrene HAP 100425 --- --- --- --- 2.50E-05 --- 3.65E-04 1.60E-03 2.32E-04 1.02E-03 --- --- 2.32E-04 1.02E-03 3.65E-04 1.60E-03 Coal Only 3.65E-04 1.60E-03Tetrachloroethylene HAP 127184 --- --- --- --- 4.30E-05 --- 6.27E-04 2.75E-03 4.00E-04 1.75E-03 --- --- 4.00E-04 1.75E-03 6.27E-04 2.75E-03 Coal Only 6.27E-04 2.75E-03Toluene HAP 108883 --- --- 3.40E-03 --- 2.40E-04 --- 3.50E-03 1.53E-02 2.23E-03 9.77E-03 3.00E-04 1.31E-03 2.53E-03 1.11E-02 3.50E-03 1.53E-02 Coal Only 3.50E-03 1.53E-02Total HpCDD HAP (POM) 37871004 --- --- --- --- 8.34E-11 --- 1.22E-09 5.33E-09 7.75E-10 3.40E-09 --- --- 7.75E-10 3.40E-09 1.22E-09 5.33E-09 Coal Only 1.22E-09 5.33E-09Total HpCDF HAP (POM) 38998753 --- --- --- --- 7.68E-11 --- 1.12E-09 4.91E-09 7.14E-10 3.13E-09 --- --- 7.14E-10 3.13E-09 1.12E-09 4.91E-09 Coal Only 1.12E-09 4.91E-09Total HxCDD HAP (POM) 34465468 --- --- --- --- 2.87E-11 --- 4.19E-10 1.83E-09 2.67E-10 1.17E-09 --- --- 2.67E-10 1.17E-09 4.19E-10 1.83E-09 Coal Only 4.19E-10 1.83E-09Total HxCDF HAP (POM) 55684941 --- --- --- --- 1.92E-10 --- 2.80E-09 1.23E-08 1.78E-09 7.82E-09 --- --- 1.78E-09 7.82E-09 2.80E-09 1.23E-08 Coal Only 2.80E-09 1.23E-08Total OCDD HAP (POM) 3268879 --- --- --- --- 4.16E-10 --- 6.07E-09 2.66E-08 3.87E-09 1.69E-08 --- --- 3.87E-09 1.69E-08 6.07E-09 2.66E-08 Coal Only 6.07E-09 2.66E-08Total OCDF HAP (POM) 39001020 --- --- --- --- 6.63E-11 --- 9.67E-10 4.24E-09 6.16E-10 2.70E-09 --- --- 6.16E-10 2.70E-09 9.67E-10 4.24E-09 Coal Only 9.67E-10 4.24E-09Total PeCDD HAP (POM) 36088229 --- --- --- --- 4.47E-11 --- 6.52E-10 2.86E-09 4.15E-10 1.82E-09 --- --- 4.15E-10 1.82E-09 6.52E-10 2.86E-09 Coal Only 6.52E-10 2.86E-09Total PeCDF HAP (POM) 30402154 --- --- --- --- 3.53E-10 --- 5.15E-09 2.26E-08 3.28E-09 1.44E-08 --- --- 3.28E-09 1.44E-08 5.15E-09 2.26E-08 Coal Only 5.15E-09 2.26E-08Total TCDD HAP (POM) 41903575 --- --- --- --- 9.28E-11 --- 1.35E-09 5.93E-09 8.62E-10 3.78E-09 --- --- 8.62E-10 3.78E-09 1.35E-09 5.93E-09 Coal Only 1.35E-09 5.93E-09Total TCDF HAP (POM) 30402143 --- --- --- --- 4.04E-10 --- 5.89E-09 2.58E-08 3.75E-09 1.64E-08 --- --- 3.75E-09 1.64E-08 5.89E-09 2.58E-08 Coal Only 5.89E-09 2.58E-08Vanadium not classified 7440622 --- --- 2.30E-03 --- --- --- --- --- --- --- 2.03E-04 8.89E-04 2.03E-04 8.89E-04 2.03E-04 8.89E-04 Combined 2.03E-04 8.89E-04

Vinyl acetate HAP 108054 --- --- --- --- 7.60E-06 --- 1.11E-04 4.86E-04 7.06E-05 3.09E-04 --- --- 7.06E-05 3.09E-04 1.11E-04 4.86E-04 Coal Only 1.11E-04 4.86E-04Xylenes HAP 1330207 --- --- --- --- 3.70E-05 --- 5.40E-04 2.36E-03 3.44E-04 1.51E-03 --- --- 3.44E-04 1.51E-03 5.40E-04 2.36E-03 Coal Only 5.40E-04 2.36E-03Zinc not classified 7440666 --- --- 2.90E-02 --- --- --- --- --- --- --- 2.56E-03 1.12E-02 2.56E-03 1.12E-02 2.56E-03 1.12E-02 Combined 2.56E-03 1.12E-02

Total POMs9 HAP NA --- --- --- --- --- --- 3.03E-04 1.33E-03 1.93E-04 8.45E-04 6.16E-05 2.70E-04 2.55E-04 1.11E-03 3.03E-04 1.33E-03 Coal Only 3.03E-04 1.33E-03

Largest Single HAP 1.75E+01 7.67E+01Total HAPs 2.00E+01 8.77E+01

NOTES:1 Emission factors for the boiler when fired with natural gas are based on USEPA AP-42, Chapter 1.4 Natural Gas Combustion, Tables 1.4-1 (Large Wall Fired Boilers Uncontrolled except for NOX which is based on the emission factor from the permit issued January 18, 2012), 1.4-2, 1.4-3, & 1.4-4, July 1998.2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (subbituminous coal 97.17 kg CO2/MMBtu and natural gas 53.06 kg CO2/MMBtu), November 29, 2013.3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (coal CH4=0.011 kg CH4/MMBtu and N2O = 0.0016 kg N2O/MMBtu and natural gas CH4 0.001 kg CH4/MMBtu and N2O 0.0001 kg N2O/MMBtu), November 29, 2013.

5 CO2e emissions are based on global warming potentials from 40 CFR 98 Subpart A, Table A-1 (CO2 = 1, CH4 = 25 and N2O = 298), November 29, 2013.6 Ammonia emission factors are based on EPA FIRE factors for uncontrolled natural gas combustion and uncontrolled bituminous/subbituminous coal combustion.7 The largest single facility-wide HAP is shown in bold.8 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as defined in Section 112(b) of the Clean Air Act and are not included in the Total HAPs.9 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.10 The boiler is not capable of operating at full capacity for both the coal burner and the natural gas burners together. Emissions are based on the natural gas burners at full capacity and the coal burner at maximum boiler capacity minus the capacity of the natural gas burners.

Federally Enforceable Permit Limits Permit No. 13700027-009 issued on January 18, 2012, and expiring January 18, 2017.Boilers 1A, 2A, and 3A total particulate potential emissions are based on a permit limit for total PM of 0.60 lb/MMBtu.Boilers 1A, 2A, and 3A particulate less than 10 microns potential emissions are based on a permit limit for PM10 of 0.074 lb/MMBtu.Boilers 1A, 2A, and 3A sulfur dioxide potential emissions (when combusting coal) are based on a permit limit for SO2 of 0.90 lb/MMBtu.

Boilers 1A and 2A have a fuel usage limit for used oil of 77 gallons per hour each and an annual not to exceed limit on used oil of 500 gallons from Boilers 1A, 2A, and 3A combined.Boiler 3A has a fuel usage limit for used oil of 86 gallons per hour and an annual not to exceed limit on used oil of 500 gallons from Boilers 1A, 2A, and 3A combined.

Pollutant EPA Pollutant Type

CAS Number

Control Efficiency

Permit Limits

Worst-Case Operating Scenario Fuel

4 Emission factors for spreader stoker firing boilers are based on USEPA AP-42, Chapter 1.1 Bituminous And Subbituminous Coal Combustion, Tables 1.1-3, 9, 12, 13, 14, 15, 18 & 19, September 1998, unless otherwise noted. The SO2 emission factor is based on the spreader stoker firing bituminous factor of 38S, where S is the sulfur content by weight (assumes a sulfur content of 1%), however, the permit limit, not the AP-42 emission factor is used for determining the PTE for SO2. The PM2.5 emission factor is taken from the permit calculations which does not contain a reference for this emission factor. The PTE for PM and PM10 are based on permit limits.

Emission Factors Potential Emissions as Permitted Potential Emissions of Combined Fuels

Annual Worst-Case Fuel

Type

PTE with Natual Gas Burner and Coal Combustion

Coal @ 100% Capacity (248 MMBtu/Hr) Coal @ 158 MMBtu/Hr Nat. Gas @ 90 MMBtu/Hr

Coal at 158 MMBtu and Nat. Gas at 90 MMBtu10

Project: Hibbing Public Utilities Prepared: NEESubject: Projected Actual Calculations Reviewed: AMCTask: Boiler #3A (EU003) Date: July 2015

Boiler 3A

Assumptions:

Nat. GasAP-421


Nat. Gas Manufacture

r4

CoalAP-425


Permitted to combust sub-bituminous and bituminous coal, natural gas, and oily rags (initial firing) lb/MMBtu lb/MMscf lb/MMBtu lb/MMBtu lb/ton lb/MMBtu Value Units lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY

Rated Capacity, MMBtu/hr 248 Particulate Matter criteria NA 95% 0.60 7.60 --- --- 12 --- 0.014 lb/MMBtu 2.15 9.21 0.67 0.02 2.15 9.14 2.82 9.16Heating Value of Coal (from Permit), MMBtu/ton 17 Particulate Matter <10 microns criteria NA 95% 0.128 7.60 --- --- 7.8 --- 0.014 lb/MMBtu 2.15 9.21 0.67 0.02 2.15 9.14 2.82 9.16Natural Gas Burner Capacity, MMBtu/hr 90 Particulate Matter <2.5 microns criteria NA 90% --- 7.60 --- --- 0.36 --- 0.014 lb/MMBtu 2.15 9.21 0.67 0.02 2.15 9.14 2.82 9.16Heating Value of Natural Gas (from permit), Btu/scf 1,020 Sulfur Dioxide criteria NA NA 0.90 0.60 --- --- 38 --- 0.5 lb/MMBtu 76.72 328.89 0.05 0.00 76.72 326.43 76.77 326.43

Max Hourly Fuel Rate for Natural Gas, 106 scf/hr 0.09 Nitrogen Oxides criteria NA --- --- 100 --- 0.1 8.8 --- 8.8 lb/ton 79.42 340.49 9.00 0.29 79.42 337.95 88.42 338.24Maximum Coal Throughput, tons/yr 125,080 Carbon Monoxide criteria NA --- --- 84 --- 0.074 5 --- 5 lb/ton 45.13 193.46 6.66 0.21 45.13 192.02 51.79 192.23Projected Actual Operating Hours9 8,574 Volatile Organic Compounds criteria NA --- --- 5.50 --- --- 0.05 --- 0.05 lb/ton 0.45 1.93 0.49 0.02 0.45 1.92 0.94 1.94

Projected Actual Operation of Gas Burner10, hr/yr 64 Lead criteria 7439921 --- --- 5.00E-04 --- --- 4.20E-04 --- 1.20E-05 lb/MMBtu 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.01

Projected Actual Operation of Coal Burner10, hr/yr 8,510 CO2 GHG NA --- --- --- 116.94 --- --- 214.16 214.16 lb/MMBtu 32,859.85 140,870.17 10,524.98 336.80 32,859.85 139,818.65 43,384.83 140,155.45

Coal Limit, tons/year NA CH4 GHG NA --- --- --- 0.002 --- --- 0.024 0.02 lb/MMBtu 3.72 15.95 0.20 0.01 3.72 15.83 3.92 15.83 N2O GHG NA --- --- --- 0.0002 --- --- 0.0035 0.00 lb/MMBtu 0.54 2.32 0.02 0.00 0.54 2.30 0.56 2.30

Conversion Factors: CO2e8 GHG NA --- --- --- 117.07 --- --- 215.82 33,114.08 141,960.07 10,535.85 337.15 33,114.08 140,900.42 43,649.93 141,237.57

lb/ton 2,000

lb/kg 2.204CO2 to CO2e 1CH4 to CO2e 25N2O to CO2e 298Btu/MMBtu 1,000,000hr/yr 8,760min/hr 60

NOTES:

1 Emission factors for the boiler when fired with natural gas are based on USEPA AP-42, Chapter 1.4 Natural Gas Combustion, Tables 1.4-1 (Large Wall Fired Boilers Uncontrolled except for NOX which is based on the emission factor from the permit issued January 18, 2012), 1.4-2, 1.4-3, & 1.4-4, July 1998.

2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (subbituminous coal 97.17 kg CO2/MMBtu and natural gas 53.06 kg CO2/MMBtu), November 29, 2013.3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (coal CH4=0.011 kg CH4/MMBtu and N2O = 0.0016 kg N2O/MMBtu and natural gas CH4 0.001 kg CH4/MMBtu and N2O 0.0001 kg N2O/MMBtu), November 29, 2013.4 CO and NOx emission factors are from manufacturer guarantees of the proposed natural gas burners.

6 Emission factors for criteria pollutants taken from 2014 Emission Inventory. These are the current emission factors used in determining annual emissions and are used here for the projected actual emissions. Sources include stack tests for particulates and lead, AP-42 for CO, NOx, and VOC, and CEMS calculations for SO2.7 A Utilization Factor was calculated to determine projected actual emissions from the modification. The Utilization Factor was calculated as 62% of maximum capacity and was based on projected boiler use estimated from 2014 usage. The utilization of Boiler #3 in 2014 is expected to be at a similar capacity in to the future.8 CO2e emissions are based on global warming potentials from 40 CFR 98 Subpart A, Table A-1 (CO2 = 1, CH4 = 25 and N2O = 298), November 29, 2013.9 Projected hours of operation for the boiler anticipated to closely follow 2014 operational data.10 Project hours for the gas burner are determined from anticipated number of startups and shutdowns per year. The boiler will fire coal for the remainder of the year. Number of start ups and shutdowns estimated to be 4 per year and approximately 8 hours per event.




Projected Actual Operation of Coal Firing

(pre-project)

Projected Actual Operation of Natural Gas Firing

Projected Actual Operation of Coal Firing

Projected Actual Operation of Boiler 3A

Coal Emission Inventory6 Coal @ 248 MMBtu/Hr with Utilization Factor7

Natural Gas @ 90 MMBtu/Hr for Projected Actual Hours

Coal @ 248 MMBtu/Hr with Utilization Factor7 Combined Fuel UsagePollutant EPA Pollutant

TypeCAS

NumberControl

Efficiency

Permit Limits

Emission Factors

Project: Hibbing Public Utilities Prepared: NEESubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler 3A EU003, Past Actual to Future Potential and Projected Actual Summary Date: June 2015

Past Actual to Future Potential Summary

Past ActualDifference From Past

ActualSER Above SER

TPY lb/hr TPY TPY TPY Y/NParticulate Matter 62.93 2007-2008 148.80 651.74 589 25 Y

Particulate Matter < 10 Microns 40.36 2005-2006 31.74 139.04 99 15 YParticulate Matter < 2.5 Microns 40.36 2005-2006 5.25 23.00 -18 10 N

Sulfur Dioxide 326.38 2008-2009 223.20 977.62 652 40 YNitrogen Oxide 243.05 2013-2014 128.38 562.29 320 40 Y

Carbon Monoxide 138.09 2013-2014 72.94 319.48 182 100 YVolatile Organic Compounds 1.38 2013-2014 0.95 4.16 3 40 N

Lead 0.06 2007-2008 0.01 0.03 -0.1 0.6 NCO2e 104,843.59 2010-2011 53,112.34 234,431.93 129,589 75,000 Y

Hours to Achieve Startup: 8Hours to Ramp Down: 8

Planned Startups: 4Planned Shutdowns: 4

Hours Starting Up and Shutting Down: 64Maximum Hourly Steam Production for Boiler 3A: 150,000

Annual Steam Production for Boiler 3A 2014: 812,953,000Annual Steam Production for Boiler 3A 2013: 474,155,000Annual Steam Production for Boiler 3A 2012: 429,035,000Annual Steam Production for Boiler 3A 2011: 705,613,000Annual Steam Production for Boiler 3A 2010: 506,249,000

Five Year Average Steam Production: 585,601,000Maximum Annual Steam Flow Rate: 1,314,000,000

Percent of Average Steam Production to Maximum Steam Production: 44.57%

Projected Actual Annual Steam Rate Based on Anticipated Operation1:

61.87%

1 Based on July 6, 2015 memo for HPU plant operations

Future Potential Emissions

Past Actual to Projected Actual Information

Pollutant Year

Past Actual to Projected Actual Summary

Baseline Actual

Projected Actual Emissions Based On

Anticpated Use of Natural Gas Burner and Utilization of Boiler 3A

Excluded Emissions

Difference from

BaselineSER Above SER

TPY TPY TPY TPY TPY Y/NParticulate Mater 62.93 2007-2008 9.16 0.00 -53.77 25 N

Particulate Matter < 10 Microns 40.36 2005-2006 9.16 0.00 -31.19 15 NParticulate Matter < 2.5 Microns 40.36 2005-2006 9.16 0.00 -31.19 10 N

Sulfur Dioxide 326.38 2008-2009 326.43 0.00 0.06 40 NNitrogen Oxide 243.05 2013-2014 338.24 0.00 95.19 40 Y

Carbon Monoxide 138.09 2013-2014 192.23 0.00 54.15 100 NVolatile Organic Compounds 1.38 2013-2014 1.94 0.00 0.55 40 N

Lead 0.06 2007-2008 0.01 0.00 -0.05 0.6 NCO2e 104,843.59 2010-2011 141,237.57 0.00 36,393.98 75,000 N

Pre-project Emissions Increase Due to Increased Demand (Excluded Emissions)

Baseline Actual

PRE-PROJECT Projected Actual

Emissions Based on Utilization of Coal Boiler

3A

Difference from Baseline (due

to demand growth)

TPY TPY TPYParticulate Mater 62.93 2007-2008 9.21 0

Particulate Matter < 10 Microns 40.36 2005-2006 9.21 0Particulate Matter < 2.5 Microns 40.36 2005-2006 9.21 0

Sulfur Dioxide 326.38 2008-2009 328.89 2.51Nitrogen Oxide 243.05 2013-2014 340.49 97.44

Carbon Monoxide 138.09 2013-2014 193.46 55.38Volatile Organic Compounds 1.38 2013-2014 1.93 0.55

Lead 0.06 2007-2008 0.01 0CO2e 104,843.59 2010-2011 141,960.07 37116.49

Past Actual to Projected Actual with Excluded Emissions

Baseline Actual

Projected Actual Emissions Based On

Anticpated Use of Natural Gas Burner and Utilization of Boiler 3A

Initial Difference from

Baseline

Excluded Emissions

(due to demand growth)

Difference from

BaselineSER Above

SER

TPY TPY TPY TPY TPY TPY Y/NParticulate Mater 62.93 2007-2008 9.16 -53.77 0.00 -53.77 25 N

Particulate Matter < 10 Microns 40.36 2005-2006 9.16 -31.19 0.00 -31.19 15 NParticulate Matter < 2.5 Microns 40.36 2005-2006 9.16 -31.19 0.00 -31.19 10 N

Sulfur Dioxide 326.38 2008-2009 326.43 0.06 2.51 -2.45 40 NNitrogen Oxide 243.05 2013-2014 338.24 95.19 97.44 -2.25 40 N

Carbon Monoxide 138.09 2013-2014 192.23 54.15 55.38 -1.23 100 NVolatile Organic Compounds 1.38 2013-2014 1.94 0.55 0.55 0.00 40 N

Lead 0.06 2007-2008 0.01 -0.05 0.00 -0.05 0.6 NCO2e 104,843.59 2010-2011 141,237.57 36,393.98 37,116.49 -722.50 75,000 N

Pollutant Years

Pollutant Years

Pollutant Years

Project: Hibbing Public Utilities Prepared: NEESubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler 3A EU003, Summary of Actual Emissions and 24-Month Average Actual Emissions Date: June 2015

Year 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2005-2006 2006-2007 2007-2008 2008-2009 2009-2010 2010-2011 2011-2012 2012-2013 2013-2014 MAX MAXPollutant TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY TPY YEAR

Particulate Matter 57.12 42.67 62.42 63.44 4.99 7.57 14.41 11.18 12.58 8.58 49.90 52.55 62.93 34.22 6.28 10.99 12.80 11.88 10.58 62.93 2007-2008Particulate Matter < 10 microns 76.16 4.55 6.66 6.77 6.66 10.59 10.01 7.76 8.74 6.19 40.36 5.61 6.72 6.72 8.63 10.30 8.89 8.25 7.46 40.36 2005-2006Particulate Matter < 2.5 microns 76.16 4.55 6.66 6.77 6.66 10.59 10.01 7.76 3.05 2.16 40.36 5.61 6.72 6.72 8.63 10.30 8.89 5.40 2.60 40.36 2005-2006

Sulfur Dioxide 128.69 164.74 330.54 278.90 373.85 187.30 209.80 158.40 192.20 306.40 146.72 247.64 304.72 326.38 280.58 198.55 184.10 175.30 249.30 326.38 2008-2009Nitrogen Oxides 139.41 136.65 207.84 210.97 209.62 178.34 272.40 154.90 174.40 311.70 138.03 172.25 209.41 210.30 193.98 225.37 213.65 164.65 243.05 243.05 2013-2014

Carbon Monoxide 79.21 77.64 118.09 119.87 119.10 101.33 154.80 88.01 99.07 177.10 78.43 97.87 118.98 119.49 110.22 128.07 121.41 93.54 138.09 138.09 2013-2014Volatile Organic Compounds 0.79 0.78 1.18 1.20 1.19 1.01 1.55 0.88 0.99 1.77 0.79 0.98 1.19 1.20 1.10 1.28 1.21 0.94 1.38 1.38 2013-2014

Lead 0.04 0.04 0.06 0.06 0.01 0.00 0.00 0.00 0.00 0.01 0.04 0.05 0.06 0.04 0.01 0.00 0.00 0.00 0.01 0.06 2007-2008CO2e 0 0 0 0 89,185 86,822 122,865 66,706 75,390 132,251 0.00 0.00 0.00 44,592.44 88,003.32 104,843.59 94,785.74 71,048.17 103,820.49 104,843.59 2010-2011

Highlighted cell indicates highest actual emission rate based on a two calendar year average.

CO2 CH4 N2O CO2eCoal Usage By Year TPY Btu/lb MMBtu/ton MMBtu/yr TPY TPY TPY TPY

2005 31,684.00 0.00 0 0 0.00 0.00 02006 31,056.00 0.00 0 0 0.00 0.00 02007 47,237.00 0.00 0 0 0.00 0.00 02008 47,948.00 0.00 0 0 0.00 0.00 02009 47,641.00 8,674.00 17.35 826,476 88,500 10.02 1.46 89,1852010 43,215.00 9,309.00 18.62 804,577 86,155 9.75 1.42 86,8222011 61,907.00 9,196.00 18.39 1,138,594 121,922 13.80 2.01 122,8652012 35,203.00 8,780.00 17.56 618,165 66,194 7.49 1.09 66,7062013 39,628.00 8,815.00 17.63 698,642 74,811 8.47 1.23 75,3902014 70,842.00 8,650.00 17.30 1,225,567 131,235 14.86 2.16 132,251

Emission Factors GHG2 kg/MMBtu lb/MMBtuCO2 from sub-bituminous 97.17 214.16CH4 from sub-bituminous 0.011 0.02N2O from sub-bituminous 0.0016 0.00

1 Actual emissions for criteria pollutants taken from actual emission reports submitted to the MPCA. 2 Potential emissions of CO2, CH4, and N2O are based on greenhouse gas emission factors from 40 CFR Part 98 Table C-1 and C-2, November 29, 2013. CO2e emissions are based on global warming potentials of CO2 = 1, CH4 = 25 and N2O = 298.Conversion kg to lb 2.204 lb/kg

Actual Emissions By Year1 Average Emissions 24-month (Based on Calendar Year)

Project: Hibbing Public Utilities Prepared: AMCSubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler #3A (EU003) Wood Pellets Test Burn Date: June 2014

Boiler 3A

Assumptions:

Nat. GasAP-421


CoalAP-424


Permitted to combust sub-bituminous and bituminous coal, natural gas, and oily rags (initial firing) lb/MMBtu lb/MMscf lb/MMBtu lb/ton lb/MMBtu lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY

Rated Capacity, MMBtu/hr 248 Particulate Matter criteria NA 95% 0.60 7.60 --- 12 --- 148.80 651.74 1.85 8.09 148.80 651.74 Coal 148.80 651.74Heating Value of Coal (from Permit), MMBtu/ton 17 Particulate Matter <10 microns criteria NA 95% 0.128 7.60 --- 7.8 --- 31.74 139.04 1.85 8.09 31.74 139.04 Coal 31.74 139.04Natural Gas Burner Capacity, MMBtu/hr 248 Particulate Matter <2.5 microns criteria NA 90% --- 7.60 --- 0.36 --- 5.25 23.00 1.85 8.09 5.25 23.00 Coal 5.25 23.00Heating Value of Natural Gas (from permit), Btu/scf 1,020 Sulfur Dioxide criteria NA NA 1.58 0.60 --- 38 --- 391.84 1716.26 0.15 0.64 391.84 1716.26 Coal 223.20 977.62

Hourly Fuel Rate for Natural Gas, 106 scf/hr 0.24 Nitrogen Oxides criteria NA --- --- 100 --- 8.8 --- 128.38 562.29 24.31 106.49 128.38 562.29 Coal 128.38 562.29Maximum Coal Throughput, tons/yr 127,793 Carbon Monoxide criteria NA --- --- 84 --- 5 --- 72.94 319.48 20.42 89.46 72.94 319.48 Coal 72.94 319.48Annual Operating Hours 8,760 Volatile Organic Compounds criteria NA --- --- 5.50 --- 0.05 --- 0.73 3.19 1.34 5.86 1.34 5.86 Natural Gas 1.34 5.86Proposed Permit Limit SO2, lb/MMBtu 0.90 Lead criteria 7439921 --- --- 5.00E-04 --- 4.20E-04 --- 6.13E-03 2.68E-02 1.22E-04 5.32E-04 0.01 0.03 Coal 0.01 0.03

Coal Limit, tons/year NA CO2 GHG NA --- --- --- 116.94 --- 214.16 53,112.34 232,632.07 29,002.17 127,029.51 53,112.34 232,632.07 Coal 53,112.34 232,632.07CH4 GHG NA --- --- --- 0.002 --- 0.024 6.01 26.33 0.55 2.39 6.01 26.33 Coal 6.01 26.33

Conversion Factors: N2O GHG NA --- --- --- 0.0002 --- 0.0035 0.87 3.83 0.05 0.24 0.87 3.83 Coal 0.87 3.83

lb/ton 2,000 CO2e5 GHG NA --- --- --- 117.07 --- 215.82 53,523.27 234,431.93 29,032.12 127,160.71 53,523.27 234,431.93 Coal 53,523.27 234,431.93

lb/kg 2.204 Ammonia 6 not classified 7664417 --- --- 3.20E+00 --- 5.65E-04 --- 8.24E-03 3.61E-02 7.78E-01 3.41E+00 0.78 3.41 Natural Gas 0.78 3.41

CO2 to CO2e 1 Benzene HAP 71432 --- --- 2.10E-03 --- 1.30E-03 --- 1.90E-02 8.31E-02 5.11E-04 2.24E-03 0.02 0.08 Coal 0.02 0.08CH4 to CO2e 25 Hydrogen Fluoride HAP 7664393 --- --- --- --- 0.15 --- 2.19 9.58E+00 --- --- 2.19 9.58 Coal 2.19 9.58N2O to CO2e 298 Hydrogen Chloride7 HAP 7647010 --- --- --- --- 1.20 --- 17.51 76.68 --- --- 17.51 76.68 Coal 17.51 76.68Btu/MMBtu 1,000,000 Mercury HAP 7439976 --- --- 2.60E-04 --- 8.30E-05 --- 1.21E-03 5.30E-03 6.32E-05 2.77E-04 0.00 0.01 Coal 1.21E-03 5.30E-03hr/yr 8,760 1,1,1-Trichloroethane HAP 71556 --- --- --- --- 2.00E-05 --- 2.92E-04 1.28E-03 --- --- 2.92E-04 1.28E-03 Coal 2.92E-04 1.28E-03min/hr 60 2,3,7,8-TCDD HAP (POM) 1746016 --- --- --- --- 1.43E-11 --- 2.09E-10 9.14E-10 --- --- 2.09E-10 9.14E-10 Coal 2.09E-10 9.14E-10

2,3,7,8-TCDF HAP (POM) 51207319 --- --- --- --- 5.10E-11 --- 7.44E-10 3.26E-09 --- --- 7.44E-10 3.26E-09 Coal 7.44E-10 3.26E-092,4-Dinitrotoluene HAP 121142 --- --- --- --- 2.80E-07 --- 4.08E-06 1.79E-05 --- --- 4.08E-06 1.79E-05 Coal 4.08E-06 1.79E-052-Chloroacetophenone HAP 532274 --- --- --- --- 7.00E-06 --- 1.02E-04 4.47E-04 --- --- 1.02E-04 4.47E-04 Coal 1.02E-04 4.47E-042-Methylnaphthalene HAP (POM) 91576 --- --- 2.40E-05 --- --- --- --- --- 5.84E-06 2.56E-05 5.84E-06 2.56E-05 Natural Gas 5.84E-06 2.56E-053-Methylchloranthrene HAP (POM) 56495 --- --- 1.80E-06 --- --- --- --- --- 4.38E-07 1.92E-06 4.38E-07 1.92E-06 Natural Gas 4.38E-07 1.92E-065-Methyl chrysene HAP (POM) 3697243 --- --- --- --- 2.20E-08 --- 3.21E-07 1.41E-06 --- --- 3.21E-07 1.41E-06 Coal 3.21E-07 1.41E-067,12-Dimethylbenz(a)anthracene HAP (POM) 57976 --- --- 1.60E-05 --- --- --- --- --- 3.89E-06 1.70E-05 3.89E-06 1.70E-05 Natural Gas 3.89E-06 1.70E-05Acenaphthene HAP (POM) 83329 --- --- 1.80E-06 --- 5.10E-07 --- 7.44E-06 3.26E-05 4.38E-07 1.92E-06 7.44E-06 3.26E-05 Coal 7.44E-06 3.26E-05Acenaphthylene HAP (POM) 208968 --- --- 1.80E-06 --- 2.50E-07 --- 3.65E-06 1.60E-05 4.38E-07 1.92E-06 3.65E-06 1.60E-05 Coal 3.65E-06 1.60E-05Acetaldehyde HAP 75070 --- --- --- --- 5.70E-04 --- 8.32E-03 3.64E-02 --- --- 8.32E-03 3.64E-02 Coal 8.32E-03 3.64E-02Acetophenone HAP 98862 --- --- --- --- 1.50E-05 --- 2.19E-04 9.58E-04 --- --- 2.19E-04 9.58E-04 Coal 2.19E-04 9.58E-04Acrolein HAP 107028 --- --- --- --- 2.90E-04 --- 4.23E-03 1.85E-02 --- --- 4.23E-03 1.85E-02 Coal 4.23E-03 1.85E-02Anthracene HAP (POM) 120127 --- --- 2.40E-06 --- 2.10E-07 --- 3.06E-06 1.34E-05 5.84E-07 2.56E-06 3.06E-06 1.34E-05 Coal 3.06E-06 1.34E-05Antimony HAP 7440360 --- --- --- --- 1.80E-05 --- 2.63E-04 1.15E-03 --- --- 2.63E-04 1.15E-03 Coal 2.63E-04 1.15E-03Arsenic HAP 7440382 --- --- 2.00E-04 --- 4.10E-04 --- 5.98E-03 2.62E-02 4.86E-05 2.13E-04 5.98E-03 2.62E-02 Coal 5.98E-03 2.62E-02

Barium 8 not classified 7440393 --- --- 4.40E-03 --- --- --- --- --- 1.07E-03 4.69E-03 1.07E-03 4.69E-03 Natural Gas 1.07E-03 4.69E-03

Benzo(a)anthracene HAP (POM) 56553 --- --- 1.80E-06 --- 8.00E-08 --- 1.17E-06 5.11E-06 4.38E-07 1.92E-06 1.17E-06 5.11E-06 Coal 1.17E-06 5.11E-06Benzo(a)pyrene HAP (POM) 50328 --- --- 1.20E-06 --- 3.80E-08 --- 5.54E-07 2.43E-06 2.92E-07 1.28E-06 5.54E-07 2.43E-06 Coal 5.54E-07 2.43E-06Benzo(b)fluoranthene HAP (POM) 205992 --- --- 1.80E-06 --- --- --- --- --- 4.38E-07 1.92E-06 4.38E-07 1.92E-06 Natural Gas 4.38E-07 1.92E-06Benzo(g,h,i)perylene HAP (POM) 191242 --- --- 1.20E-06 --- 2.70E-08 --- 3.94E-07 1.73E-06 2.92E-07 1.28E-06 3.94E-07 1.73E-06 Coal 3.94E-07 1.73E-06Benzo(k)fluoranthene HAP (POM) 207089 --- --- 1.80E-06 --- 1.10E-07 --- 1.60E-06 7.03E-06 4.38E-07 1.92E-06 1.60E-06 7.03E-06 Coal 1.60E-06 7.03E-06Benzyl chloride HAP 100447 --- --- --- --- 7.00E-04 --- 1.02E-02 4.47E-02 --- --- 1.02E-02 4.47E-02 Coal 1.02E-02 4.47E-02Beryllium HAP 7440417 --- --- 1.20E-05 --- 2.10E-05 --- 3.06E-04 1.34E-03 2.92E-06 1.28E-05 3.06E-04 1.34E-03 Coal 3.06E-04 1.34E-03Biphenyl HAP (POM) 92524 --- --- --- --- 1.70E-06 --- 2.48E-05 1.09E-04 --- --- 2.48E-05 1.09E-04 Coal 2.48E-05 1.09E-04Bis(2-ethylhexyl)phthalate (DEHP) HAP 117817 --- --- --- --- 7.30E-05 --- 1.06E-03 4.66E-03 --- --- 1.06E-03 4.66E-03 Coal 1.06E-03 4.66E-03Bromoform HAP 75252 --- --- --- --- 3.90E-05 --- 5.69E-04 2.49E-03 --- --- 5.69E-04 2.49E-03 Coal 5.69E-04 2.49E-03Butane not classified 106978 --- --- 2.10E+00 --- --- --- --- --- 5.11E-01 2.24E+00 5.11E-01 2.24E+00 Natural Gas 5.11E-01 2.24E+00

Cadmium HAP 7440439 --- --- 1.10E-03 --- 5.10E-05 --- 7.44E-04 3.26E-03 2.67E-04 1.17E-03 7.44E-04 3.26E-03 Coal 7.44E-04 3.26E-03Carbon disulfide HAP 75150 --- --- --- --- 1.30E-04 --- 1.90E-03 8.31E-03 --- --- 1.90E-03 8.31E-03 Coal 1.90E-03 8.31E-03Chlorobenzene HAP 108907 --- --- --- --- 2.20E-05 --- 3.21E-04 1.41E-03 --- --- 3.21E-04 1.41E-03 Coal 3.21E-04 1.41E-03Chloroform HAP 67663 --- --- --- --- 5.90E-05 --- 8.61E-04 3.77E-03 --- --- 8.61E-04 3.77E-03 Coal 8.61E-04 3.77E-03Chromium HAP 7440473 --- --- 1.40E-03 --- 2.60E-04 --- 3.79E-03 1.66E-02 3.40E-04 1.49E-03 3.79E-03 1.66E-02 Coal 3.79E-03 1.66E-02Chromium (VI) HAP 18540292 --- --- --- --- 7.90E-05 --- 1.15E-03 5.05E-03 --- --- 1.15E-03 5.05E-03 Coal 1.15E-03 5.05E-03Chrysene HAP (POM) 218019 --- --- 1.80E-06 --- 1.00E-07 --- 1.46E-06 6.39E-06 4.38E-07 1.92E-06 1.46E-06 6.39E-06 Coal 1.46E-06 6.39E-06Cobalt HAP 7440484 --- --- 8.40E-05 --- 1.00E-04 --- 1.46E-03 6.39E-03 2.04E-05 8.95E-05 1.46E-03 6.39E-03 Coal 1.46E-03 6.39E-03Copper not classified 7440508 --- --- 8.50E-04 --- --- --- --- --- 2.07E-04 9.05E-04 2.07E-04 9.05E-04 Natural Gas 2.07E-04 9.05E-04

Cumene HAP 98828 --- --- --- --- 5.30E-06 --- 7.73E-05 3.39E-04 --- --- 7.73E-05 3.39E-04 Coal 7.73E-05 3.39E-04Cyanide HAP 57125 --- --- --- --- 2.50E-03 --- 3.65E-02 1.60E-01 --- --- 3.65E-02 1.60E-01 Coal 3.65E-02 1.60E-01Dibenzo(a,h)anthracene HAP (POM) 53703 --- --- 1.20E-06 --- --- --- --- --- 2.92E-07 1.28E-06 2.92E-07 1.28E-06 Natural Gas 2.92E-07 1.28E-06Dichlorobenzene HAP 25321226 --- --- 1.20E-03 --- --- --- --- --- 2.92E-04 1.28E-03 2.92E-04 1.28E-03 Natural Gas 2.92E-04 1.28E-03Dimethyl sulfate HAP 77781 --- --- --- --- 4.80E-05 --- 7.00E-04 3.07E-03 --- --- 7.00E-04 3.07E-03 Coal 7.00E-04 3.07E-03


CAS Number

Control Efficiency

Permit Limits

Emission Factors Potential Emissions as Permitted

Worst-Case Fuel Type

Proposed

Coal Nat. Gas Worst-Case Fuel Limited Emission Rate

Nat. GasAP-421


CoalAP-424


lb/MMBtu lb/MMscf lb/MMBtu lb/ton lb/MMBtu lb/hour TPY lb/hour TPY lb/hour TPY lb/hour TPY

Ethane not classified 74840 --- --- 3.10E+00 --- --- --- --- --- 7.54E-01 3.30E+00 7.54E-01 3.30E+00 Natural Gas 7.54E-01 3.30E+00

Ethyl benzene HAP 100414 --- --- --- --- 9.40E-05 --- 1.37E-03 6.01E-03 --- --- 1.37E-03 6.01E-03 Coal 1.37E-03 6.01E-03Ethyl chloride HAP 75003 --- --- --- --- 4.20E-05 --- 6.13E-04 2.68E-03 --- --- 6.13E-04 2.68E-03 Coal 6.13E-04 2.68E-03Ethylene dibromide HAP 106934 --- --- --- --- 1.20E-06 --- 1.75E-05 7.67E-05 --- --- 1.75E-05 7.67E-05 Coal 1.75E-05 7.67E-05Ethylene dichloride HAP 107062 --- --- --- --- 4.00E-05 --- 5.84E-04 2.56E-03 --- --- 5.84E-04 2.56E-03 Coal 5.84E-04 2.56E-03Fluoranthene HAP (POM) 206440 --- --- 3.00E-06 --- 7.10E-07 --- 1.04E-05 4.54E-05 7.29E-07 3.19E-06 1.04E-05 4.54E-05 Coal 1.04E-05 4.54E-05Fluorene HAP (POM) 86737 --- --- 2.80E-06 --- 9.10E-07 --- 1.33E-05 5.81E-05 6.81E-07 2.98E-06 1.33E-05 5.81E-05 Coal 1.33E-05 5.81E-05Formaldehyde HAP 50000 --- --- 7.50E-02 --- 2.40E-04 --- 3.50E-03 1.53E-02 1.82E-02 7.99E-02 1.82E-02 7.99E-02 Natural Gas 1.82E-02 7.99E-02Hexane HAP 110543 --- --- 1.80E+00 --- 6.70E-05 --- 9.77E-04 4.28E-03 4.38E-01 1.92E+00 4.38E-01 1.92E+00 Natural Gas 4.38E-01 1.92E+00Indeno(1,2,3-cd)pyrene HAP (POM) 193395 --- --- 1.80E-06 --- 6.10E-08 --- 8.90E-07 3.90E-06 4.38E-07 1.92E-06 8.90E-07 3.90E-06 Coal 8.90E-07 3.90E-06Isophorone HAP 78591 --- --- --- --- 5.80E-04 --- 8.46E-03 3.71E-02 --- --- 8.46E-03 3.71E-02 Coal 8.46E-03 3.71E-02Magnesium not classified 7439954 --- --- --- --- 1.10E-02 --- 1.60E-01 7.03E-01 --- --- 1.60E-01 7.03E-01 Coal 1.60E-01 7.03E-01

Manganese HAP 7439965 --- --- 3.80E-04 --- 4.90E-04 --- 7.15E-03 3.13E-02 9.24E-05 4.05E-04 7.15E-03 3.13E-02 Coal 7.15E-03 3.13E-02Methyl bromide HAP 74839 --- --- --- --- 1.60E-04 --- 2.33E-03 1.02E-02 --- --- 2.33E-03 1.02E-02 Coal 2.33E-03 1.02E-02Methyl chloride HAP 74873 --- --- --- --- 5.30E-04 --- 7.73E-03 3.39E-02 --- --- 7.73E-03 3.39E-02 Coal 7.73E-03 3.39E-02Methyl ethyl ketone (MEK) not classified 78933 --- --- --- --- 3.90E-04 --- 5.69E-03 2.49E-02 --- --- 5.69E-03 2.49E-02 Coal 5.69E-03 2.49E-02

Methyl hydrazine HAP 60344 --- --- --- --- 1.70E-04 --- 2.48E-03 1.09E-02 --- --- 2.48E-03 1.09E-02 Coal 2.48E-03 1.09E-02Methyl methacrylate HAP 80626 --- --- --- --- 2.00E-05 --- 2.92E-04 1.28E-03 --- --- 2.92E-04 1.28E-03 Coal 2.92E-04 1.28E-03Methyl tert butyl ether HAP 1634044 --- --- --- --- 3.50E-05 --- 5.11E-04 2.24E-03 --- --- 5.11E-04 2.24E-03 Coal 5.11E-04 2.24E-03Methylene chloride HAP 75092 --- --- --- --- 2.90E-04 --- 4.23E-03 1.85E-02 --- --- 4.23E-03 1.85E-02 Coal 4.23E-03 1.85E-02Molybdenum not classified 7439987 --- --- 1.10E-03 --- --- --- --- --- 2.67E-04 1.17E-03 2.67E-04 1.17E-03 Natural Gas 2.67E-04 1.17E-03

Naphthalene HAP (POM) 91203 --- --- 6.10E-04 --- 1.30E-05 --- 1.90E-04 8.31E-04 1.48E-04 6.50E-04 1.90E-04 8.31E-04 Coal 1.90E-04 8.31E-04Nickel HAP 7440020 --- --- 2.10E-03 --- 2.80E-04 --- 4.08E-03 1.79E-02 5.11E-04 2.24E-03 4.08E-03 1.79E-02 Coal 4.08E-03 1.79E-02Pentane not classified 109660 --- --- 2.60E+00 --- --- --- --- --- 6.32E-01 2.77E+00 6.32E-01 2.77E+00 Natural Gas 6.32E-01 2.77E+00

Phenanthrene HAP (POM) 85018 --- --- 1.70E-05 --- 2.70E-06 --- 3.94E-05 1.73E-04 4.13E-06 1.81E-05 3.94E-05 1.73E-04 Coal 3.94E-05 1.73E-04Phenol HAP 108952 --- --- --- --- 1.60E-05 --- 2.33E-04 1.02E-03 --- --- 2.33E-04 1.02E-03 Coal 2.33E-04 1.02E-03Propane not classified 74986 --- --- 1.60E+00 --- --- --- --- --- 3.89E-01 1.70E+00 3.89E-01 1.70E+00 Natural Gas 3.89E-01 1.70E+00

Propionaldehyde HAP 123386 --- --- --- --- 3.80E-04 --- 5.54E-03 2.43E-02 --- --- 5.54E-03 2.43E-02 Coal 5.54E-03 2.43E-02Pyrene HAP (POM) 129000 --- --- 5.00E-06 --- 3.30E-07 --- 4.81E-06 2.11E-05 1.22E-06 5.32E-06 4.81E-06 2.11E-05 Coal 4.81E-06 2.11E-05Selenium HAP 7782492 --- --- 2.40E-05 --- 1.30E-03 --- 1.90E-02 8.31E-02 5.84E-06 2.56E-05 1.90E-02 8.31E-02 Coal 1.90E-02 8.31E-02Styrene HAP 100425 --- --- --- --- 2.50E-05 --- 3.65E-04 1.60E-03 --- --- 3.65E-04 1.60E-03 Coal 3.65E-04 1.60E-03Tetrachloroethylene HAP 127184 --- --- --- --- 4.30E-05 --- 6.27E-04 2.75E-03 --- --- 6.27E-04 2.75E-03 Coal 6.27E-04 2.75E-03Toluene HAP 108883 --- --- 3.40E-03 --- 2.40E-04 --- 3.50E-03 1.53E-02 8.27E-04 3.62E-03 3.50E-03 1.53E-02 Coal 3.50E-03 1.53E-02Total HpCDD HAP (POM) 37871004 --- --- --- --- 8.34E-11 --- 1.22E-09 5.33E-09 --- --- 1.22E-09 5.33E-09 Coal 1.22E-09 5.33E-09Total HpCDF HAP (POM) 38998753 --- --- --- --- 7.68E-11 --- 1.12E-09 4.91E-09 --- --- 1.12E-09 4.91E-09 Coal 1.12E-09 4.91E-09Total HxCDD HAP (POM) 34465468 --- --- --- --- 2.87E-11 --- 4.19E-10 1.83E-09 --- --- 4.19E-10 1.83E-09 Coal 4.19E-10 1.83E-09Total HxCDF HAP (POM) 55684941 --- --- --- --- 1.92E-10 --- 2.80E-09 1.23E-08 --- --- 2.80E-09 1.23E-08 Coal 2.80E-09 1.23E-08Total OCDD HAP (POM) 3268879 --- --- --- --- 4.16E-10 --- 6.07E-09 2.66E-08 --- --- 6.07E-09 2.66E-08 Coal 6.07E-09 2.66E-08Total OCDF HAP (POM) 39001020 --- --- --- --- 6.63E-11 --- 9.67E-10 4.24E-09 --- --- 9.67E-10 4.24E-09 Coal 9.67E-10 4.24E-09Total PeCDD HAP (POM) 36088229 --- --- --- --- 4.47E-11 --- 6.52E-10 2.86E-09 --- --- 6.52E-10 2.86E-09 Coal 6.52E-10 2.86E-09Total PeCDF HAP (POM) 30402154 --- --- --- --- 3.53E-10 --- 5.15E-09 2.26E-08 --- --- 5.15E-09 2.26E-08 Coal 5.15E-09 2.26E-08Total TCDD HAP (POM) 41903575 --- --- --- --- 9.28E-11 --- 1.35E-09 5.93E-09 --- --- 1.35E-09 5.93E-09 Coal 1.35E-09 5.93E-09Total TCDF HAP (POM) 30402143 --- --- --- --- 4.04E-10 --- 5.89E-09 2.58E-08 --- --- 5.89E-09 2.58E-08 Coal 5.89E-09 2.58E-08Vanadium not classified 7440622 --- --- 2.30E-03 --- --- --- --- --- 5.59E-04 2.45E-03 5.59E-04 2.45E-03 Natural Gas 5.59E-04 2.45E-03

Vinyl acetate HAP 108054 --- --- --- --- 7.60E-06 --- 1.11E-04 4.86E-04 --- --- 1.11E-04 4.86E-04 Coal 1.11E-04 4.86E-04Xylenes HAP 1330207 --- --- --- --- 3.70E-05 --- 5.40E-04 2.36E-03 --- --- 5.40E-04 2.36E-03 Coal 5.40E-04 2.36E-03Zinc not classified 7440666 --- --- 2.90E-02 --- --- --- --- --- 7.05E-03 3.09E-02 7.05E-03 3.09E-02 Natural Gas 7.05E-03 3.09E-02

Total POMs9 HAP NA --- --- --- --- --- --- 3.03E-04 1.33E-03 1.70E-04 7.44E-04 3.03E-04 1.33E-03 Coal 3.03E-04 1.33E-03Largest Single HAP 17.51 76.68Total HAPs 20.32 89.00

NOTES:


2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (subbituminous coal 97.17 kg CO2/MMBtu and natural gas 53.06 kg CO2/MMBtu), November 29, 2013.

3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (coal CH4=0.011 kg CH4/MMBtu and N2O = 0.0016 kg N2O/MMBtu and natural gas CH4 0.001 kg CH4/MMBtu and N2O 0.0001 kg N2O/MMBtu), November 29, 2013.

5 CO2e emissions are based on global warming potentials from 40 CFR 98 Subpart A, Table A-1 (CO2 = 1, CH4 = 25 and N2O = 298), November 29, 2013.6 Ammonia emission factors are based on EPA FIRE factors for uncontrolled natural gas combustion and uncontrolled bituminous/subbituminous coal combustion.7 The largest single facility-wide HAP is shown in bold.8 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as defined in Section 112(b) of the Clean Air Act and are not included in the Total HAPs.9 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.




CAS Number

Control Efficiency

Permit LimitsEmission Factors Potential Emissions as Permitted



Proposed


Project: Hibbing Public Utilities Prepared: NEESubject: Potential to Emit Calculations Reviewed: AMCTask: Boiler #3A (EU003) Wood Pellets Test Burn Date: July 2015

Assumptions:

Rated Capacity of Boiler #3, MMBtu/hr 248

Heating Value of Pellet (provided from supplier), Btu/lb 10,739 lb/MMBtu lb/MMBtu lb/hr TPY lb/hr TPY lb/hr TPY

Heating Value of Pellet, MMBtu/ton 21.48 Particulate Matter criteria NA 0.417 --- 2.59 1.12 148.80 1.61 -146.21 -0.49Amount of Fuel for Test Burn, tons 250 Particulate Matter < 10 Microns criteria NA 0.377 --- 2.34 1.01 31.74 0.34 -29.41 0.67Total MMBtu Combusted in Test, MMBtu/test 5,369.50 Particulate Matter < 2.5 Microns criteria NA 0.327 --- 4.05 0.88 5.25 0.06 -1.20 0.82Time of Test based on Rated Capacity of Boiler #3, hr/test 21.65 Sulfur Dioxide criteria NA 0.025 --- 6.20 0.07 223.20 2.42 -217.00 -2.35Ash %, (provided from supplier) 0.74 Nitrogen Oxides criteria NA 0.49 --- 121.52 1.32 128.38 1.39 -6.86 -0.07Ash% chipped wood 2 Carbon Monoxide criteria NA 0.600 --- 148.80 1.61 72.94 0.79 75.86 0.82

Volatile Organic Compounds criteria NA 0.017 --- 4.22 0.05 0.73 0.01 3.49 0.04Conversion Factors: Lead criteria 4739921 0.00003 --- 0.01 0.00 0.01 0.00 0.00 0.00

lb/ton 2,000 CO2e5 GHG NA --- 209.50 51,955 562.45 53,523 579.42 -1,568 -17

Btu/MMBtu 1,000,000 CO2 GHG NA --- 206.74 51,270 555.03 53,112 574.97 -1,842 -20hr/yr 8,760 CH4 GHG NA --- 0.016 3.94 0.0426 6.01 0.07 -2.08 -0.02

N2O GHG NA --- 0.0079 1.97 0.0213 0.87 0.0095 1.09 0.01

Ammonia 6,7 not classified 7664417 0.31 --- 3.58 0.04 0.01 0.0001 3.57 0.04

Hydrogen Fluoride8 HAP 7664393 1.60E-03 --- 3.97E-01 4.30E-03 2.19E+00 0.02 -1.79E+00 -1.94E-021,1,1-Trichloroethane (methyl chloroform) HAP 71556 3.10E-05 --- 7.69E-03 8.32E-05 2.92E-04 3.16E-06 7.40E-03 8.01E-051,2-Dichloroethane (ethylene dichloride) HAP 107062 2.90E-05 --- 7.19E-03 7.79E-05 5.84E-04 6.32E-06 6.61E-03 7.15E-05

1,2-Dichloropropane (propylene dichloride) HAP 78875 3.30E-05 --- 8.18E-03 8.86E-05 0.00E+00 0.00E+00 8.18E-03 8.86E-052,3,7,8-TCDD HAP (POM) 1746016 1.06E-11 --- 2.63E-09 2.85E-11 2.09E-10 2.26E-12 2.42E-09 2.62E-112,3,7,8-TCDF HAP (POM) 51207319 5.05E-11 --- 1.25E-08 1.36E-10 7.44E-10 8.05E-12 1.18E-08 1.28E-10

2,4,6-Trichlorophenol HAP 88062 1.14E-08 --- 2.83E-06 3.06E-08 0.00E+00 0.00E+00 2.83E-06 3.06E-082,4-Dinitrophenol HAP 51285 9.33E-08 --- 2.31E-05 2.50E-07 0.00E+00 0.00E+00 2.31E-05 2.50E-072,4-Dinitrotoluene HAP 121142 --- --- 0.00E+00 0.00E+00 4.08E-06 4.42E-08 -4.08E-06 -4.42E-08

2-Chloroacetophenone HAP 532274 --- --- 0.00E+00 0.00E+00 1.02E-04 1.11E-06 -1.02E-04 -1.11E-062-Methylnaphthalene HAP (POM) 91576 1.60E-07 --- 3.97E-05 4.30E-07 0.00E+00 0.00E+00 3.97E-05 4.30E-07

4-Nitrophenol HAP 100027 1.71E-07 --- 4.24E-05 4.59E-07 0.00E+00 0.00E+00 4.24E-05 4.59E-075-Methyl chrysene HAP (POM) 3697243 --- --- 0.00E+00 0.00E+00 3.21E-07 3.47E-09 -3.21E-07 -3.47E-09

Acenaphthene HAP (POM) 83329 6.29E-09 --- 1.56E-06 1.69E-08 7.44E-06 8.05E-08 -5.88E-06 -6.37E-08Acenaphthylene HAP (POM) 208968 1.28E-06 --- 3.17E-04 3.44E-06 3.65E-06 3.95E-08 3.14E-04 3.40E-06

Acetaldehyde HAP 75070 2.34E-04 --- 5.80E-02 6.28E-04 8.32E-03 9.00E-05 4.97E-02 5.38E-04Acetophenone HAP 98862 3.20E-09 --- 7.94E-07 8.59E-09 2.19E-04 2.37E-06 -2.18E-04 -2.36E-06

Acrolein9 HAP 107028 4.36E-05 --- 1.08E-02 1.17E-04 4.23E-03 4.58E-05 6.58E-03 7.13E-05Anthracene HAP (POM) 120127 4.17E-08 --- 1.03E-05 1.12E-07 3.06E-06 3.32E-08 7.28E-06 7.88E-08Antimony HAP 7440360 1.17E-05 --- 2.90E-03 3.14E-05 2.63E-04 2.84E-06 2.64E-03 2.86E-05Arsenic HAP 7440382 3.25E-05 --- 8.06E-03 8.73E-05 5.98E-03 6.47E-05 2.08E-03 2.25E-05Barium not classified 7440393 1.70E-04 --- 4.22E-02 4.56E-04 0.00E+00 0.00E+00 4.22E-02 4.56E-04

Benzene HAP 71432 7.10E-04 --- 1.76E-01 1.91E-03 1.90E-02 2.05E-04 1.57E-01 1.70E-03Benzo(a)anthracene HAP (POM) 56553 6.50E-08 --- 1.61E-05 1.75E-07 1.17E-06 1.26E-08 1.50E-05 1.62E-07

Benzo(a)pyrene HAP (POM) 50328 2.60E-06 --- 6.45E-04 6.98E-06 5.54E-07 6.00E-09 6.44E-04 6.97E-06Benzo(b)fluoranthene HAP (POM) 205992 1.00E-07 --- 2.48E-05 2.68E-07 0.00E+00 0.00E+00 2.48E-05 2.68E-07Benzo(g,h,i)perylene HAP (POM) 191242 9.30E-08 --- 2.31E-05 2.50E-07 3.94E-07 4.26E-09 2.27E-05 2.45E-07Benzo(k)fluoranthene HAP (POM) 207089 3.60E-08 --- 8.93E-06 9.67E-08 1.60E-06 1.74E-08 7.32E-06 7.93E-08

Benzyl chloride HAP 100447 --- --- 0.00E+00 0.00E+00 1.02E-02 1.11E-04 -1.02E-02 -1.11E-04Beryllium HAP 7440417 1.78E-06 --- 4.41E-04 4.78E-06 3.06E-04 3.32E-06 1.35E-04 1.46E-06Biphenyl HAP (POM) 92524 --- --- 0.00E+00 0.00E+00 2.48E-05 2.68E-07 -2.48E-05 -2.68E-07

bis(2-Ehtylhexyl)phthalate (DEHP) HAP 117817 4.70E-08 --- 1.17E-05 1.26E-07 1.06E-03 1.15E-05 -1.05E-03 -1.14E-05Bromoform HAP 75252 --- --- 0.00E+00 0.00E+00 5.69E-04 6.16E-06 -5.69E-04 -6.16E-06

Bromomethane (Methyl bromide) HAP 74839 1.50E-05 --- 3.72E-03 4.03E-05 2.33E-03 2.53E-05 1.39E-03 1.50E-05Cadmium HAP 7440439 1.80E-06 --- 4.46E-04 4.83E-06 7.44E-04 8.05E-06 -2.98E-04 -3.22E-06

Carbon disulfide HAP 75150 --- --- 0.00E+00 0.00E+00 1.90E-03 2.05E-05 -1.90E-03 -2.05E-05Carbon Tetrachloride HAP 56235 4.50E-05 --- 1.12E-02 1.21E-04 0.00E+00 0.00E+00 1.12E-02 1.21E-04

Chlorine HAP 7782505 7.90E-04 --- 1.96E-01 2.12E-03 0.00E+00 0.00E+00 1.96E-01 2.12E-03Chlorobenzene HAP 108907 3.30E-05 --- 8.18E-03 8.86E-05 3.21E-04 3.47E-06 7.86E-03 8.51E-05

Chloroform HAP 67663 2.80E-05 --- 6.94E-03 7.52E-05 8.61E-04 9.32E-06 6.08E-03 6.59E-05Methyl Chloride (Chloromethane) HAP 74873 2.30E-05 --- 5.70E-03 6.17E-05 7.73E-03 8.37E-05 -2.03E-03 -2.20E-05

Chromium HAP 7440473 1.46E-06 --- 3.62E-04 3.92E-06 3.79E-03 4.11E-05 -3.43E-03 -3.71E-05Chromium (VI) HAP 18540292 1.63E-06 --- 4.04E-04 4.38E-06 1.15E-03 1.25E-05 -7.48E-04 -8.10E-06

CAS Number

WoodAP-421,2

Wood 40 CFR Part 983,4

Emissions From Test Burn Emission Offset From

Replacing Coal with Wood Pellets During Test Burn

Change in PTE Emissions Due to Test

Burn of Wood Pellets in Boiler #3AWood

Test Burn Boiler #3A


WoodAP-421,2


lb/MMBtu lb/MMBtu lb/hr TPY lb/hr TPY lb/hr TPYChrysene HAP (POM) 218019 2.64E-09 --- 6.55E-07 2.87E-06 1.46E-06 6.39E-06 -8.04E-07 -3.52E-06Cobalt HAP 7440484 3.54E-07 --- 8.78E-05 3.85E-04 1.46E-03 6.39E-03 -1.37E-03 -6.01E-03Copper not classified 7440508 4.90E-05 --- 1.22E-02 5.32E-02 0.00E+00 0.00E+00 1.22E-02 5.32E-02

Cumene HAP 98828 --- --- 0.00E+00 0.00E+00 7.73E-05 3.39E-04 -7.73E-05 -3.39E-04Cyanide HAP 57125 --- --- 0.00E+00 0.00E+00 3.65E-02 1.60E-01 -3.65E-02 -1.60E-01

Dibenzo(a,h)anthracene HAP (POM) 53703 9.10E-09 --- 2.26E-06 9.88E-06 0.00E+00 0.00E+00 2.26E-06 9.88E-06Dichloromethane (methylene chloride) HAP 75092 2.90E-04 --- 7.19E-02 3.15E-01 4.23E-03 1.85E-02 6.77E-02 2.96E-01

Dimethyl sulfate HAP 77781 --- --- 0.00E+00 0.00E+00 7.00E-04 3.07E-03 -7.00E-04 -3.07E-03Ethyl benzene HAP 100414 3.10E-05 --- 7.69E-03 3.37E-02 1.37E-03 6.01E-03 6.32E-03 2.77E-02Ethyl chloride HAP 75003 --- --- 0.00E+00 0.00E+00 6.13E-04 2.68E-03 -6.13E-04 -2.68E-03

Ethylene dibromide HAP 106934 --- --- 0.00E+00 0.00E+00 1.75E-05 7.67E-05 -1.75E-05 -7.67E-05Fluoranthene HAP (POM) 206440 1.60E-06 --- 3.97E-04 1.74E-03 1.04E-05 4.54E-05 3.86E-04 1.69E-03

Fluorene HAP (POM) 86737 3.40E-06 --- 8.43E-04 3.69E-03 1.33E-05 5.81E-05 8.30E-04 3.64E-03Formaldehyde HAP 50000 1.40E-03 --- 3.47E-01 1.52E+00 3.50E-03 1.53E-02 3.44E-01 1.51E+00

Hexane HAP 110543 --- --- 0.00E+00 0.00E+00 9.77E-04 4.28E-03 -9.77E-04 -4.28E-03

Hydrogen Chloride10 HAP 7647010 1.90E-02 --- 4.71E+00 2.06E+01 1.75E+01 7.67E+01 -1.28E+01 -5.60E+01Indeno(1,2,3-cd)pyrene HAP (POM) 193395 8.70E-08 --- 2.16E-05 9.45E-05 8.90E-07 3.90E-06 2.07E-05 9.06E-05

Isophorone HAP 78591 --- --- 0.00E+00 0.00E+00 8.46E-03 3.71E-02 -8.46E-03 -3.71E-02Magnesium not classified 7439954 --- --- 0.00E+00 0.00E+00 1.60E-01 7.03E-01 -1.60E-01 -7.03E-01

Manganese HAP 7439965 1.30E-03 --- 3.22E-01 1.41E+00 7.15E-03 3.13E-02 3.15E-01 1.38E+00Mercury HAP 7439976 3.50E-06 --- 8.68E-04 3.80E-03 1.21E-03 5.30E-03 -3.43E-04 -1.50E-03

Methyl ethyl ketone (MEK) not classified 78933 --- --- 0.00E+00 0.00E+00 5.69E-03 2.49E-02 -5.69E-03 -2.49E-02

Methyl hydrazine HAP 60344 --- --- 0.00E+00 0.00E+00 2.48E-03 1.09E-02 -2.48E-03 -1.09E-02Methyl methacrylate HAP 80626 --- --- 0.00E+00 0.00E+00 2.92E-04 1.28E-03 -2.92E-04 -1.28E-03

Methyl tert butyl ether HAP 1634044 --- --- 0.00E+00 0.00E+00 5.11E-04 2.24E-03 -5.11E-04 -2.24E-03Molybdenum not classified 7439987 2.10E-06 --- 5.21E-04 2.28E-03 0.00E+00 0.00E+00 5.21E-04 2.28E-03

Naphthalene HAP (POM) 91203 6.82E-05 --- 1.69E-02 7.41E-02 1.90E-04 8.31E-04 1.67E-02 7.33E-02Nickel HAP 7440020 2.27E-06 --- 5.63E-04 2.47E-03 4.08E-03 1.79E-02 -3.52E-03 -1.54E-02

Phenanthrene HAP (POM) 85018 1.36E-06 --- 3.37E-04 1.48E-03 3.94E-05 1.73E-04 2.98E-04 1.30E-03Phenol HAP 108952 1.25E-05 --- 3.10E-03 1.36E-02 2.33E-04 1.02E-03 2.87E-03 1.26E-02

Phosphorus HAP 7723140 1.93E-05 --- 4.79E-03 2.10E-02 0.00E+00 0.00E+00 4.79E-03 2.10E-02Propionaldehyde HAP 123386 6.10E-05 --- 1.51E-02 6.63E-02 5.54E-03 2.43E-02 9.58E-03 4.20E-02

Pyrene HAP (POM) 129000 --- --- 0.00E+00 0.00E+00 4.81E-06 2.11E-05 -4.81E-06 -2.11E-05Selenium HAP 7782492 2.44E-06 --- 6.05E-04 2.65E-03 1.90E-02 8.31E-02 -1.84E-02 -8.04E-02Styrene HAP 100425 1.90E-03 --- 4.71E-01 2.06E+00 3.65E-04 1.60E-03 4.71E-01 2.06E+00

Tetrachloroethylene HAP 127184 --- --- 0.00E+00 0.00E+00 6.27E-04 2.75E-03 -6.27E-04 -2.75E-03Toluene HAP 108883 2.13E-05 --- 5.28E-03 2.31E-02 3.50E-03 1.53E-02 1.78E-03 7.80E-03

Total HpCDD HAP (POM) 37871004 --- --- 0.00E+00 0.00E+00 1.22E-09 5.33E-09 -1.22E-09 -5.33E-09Total HpCDF HAP (POM) 38998753 --- --- 0.00E+00 0.00E+00 1.12E-09 4.91E-09 -1.12E-09 -4.91E-09Total HxCDD HAP (POM) 34465468 --- --- 0.00E+00 0.00E+00 4.19E-10 1.83E-09 -4.19E-10 -1.83E-09Total HXCDF HAP (POM) 55684941 --- --- 0.00E+00 0.00E+00 2.80E-09 1.23E-08 -2.80E-09 -1.23E-08Total OCDD HAP (POM) 3268879 --- --- 0.00E+00 0.00E+00 6.07E-09 2.66E-08 -6.07E-09 -2.66E-08Total OCDF HAP (POM) 39001020 --- --- 0.00E+00 0.00E+00 9.67E-10 4.24E-09 -9.67E-10 -4.24E-09

Total PeCDD HAP (POM) 36088229 --- --- 0.00E+00 0.00E+00 6.52E-10 2.86E-09 -6.52E-10 -2.86E-09Total PeCDF HAP (POM) 30402154 --- --- 0.00E+00 0.00E+00 5.15E-09 2.26E-08 -5.15E-09 -2.26E-08Total TCDD HAP (POM) 41903575 --- --- 0.00E+00 0.00E+00 1.35E-09 5.93E-09 -1.35E-09 -5.93E-09Total TCDF HAP (POM) 30402143 --- --- 0.00E+00 0.00E+00 5.89E-09 2.58E-08 -5.89E-09 -2.58E-08Vinyl acetate HAP 108054 --- --- 0.00E+00 0.00E+00 1.11E-04 4.86E-04 -1.11E-04 -4.86E-04Vinyl Chloride HAP 75014 1.80E-05 --- 4.46E-03 1.96E-02 0.00E+00 0.00E+00 4.46E-03 1.96E-02

Xylenes HAP 1330207 2.50E-05 --- 6.20E-03 2.72E-02 5.40E-04 2.36E-03 5.66E-03 2.48E-02Zinc not classified 7440666 4.20E-04 --- 1.04E-01 4.56E-01 0.00E+00 0.00E+00 1.04E-01 4.56E-01

Total POMs11 HAP NA --- --- 1.96E-02 8.59E-02 3.03E-04 1.33E-03 1.93E-02 8.45E-02Largest Single HAP --- --- --- --- 4.71E+00 2.06E+01 1.75E+01 7.67E+01 -1.28E+01 -5.60E+01

Total HAPs --- --- --- --- 6.90E+00 3.02E+01 1.99E+01 8.70E+01 -1.30E+01 -5.68E+01

3 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (wood 93.80 kg CO2/MMBtu), November 29, 2013.4 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (natural gas CH4 = 0.001 kg CH4/MMBtu and N2O = 0.0001 kg N2O/MMBtu and wood CH4 = 0.0072 kg CH4/MMBtu and N2O 0.0036 kg N2O/MMBtu), November 29, 2013.

5 CO2e emissions are based on global warming potential of CO2=1, CH4=25, and N2O=298.6 Ammonia emission factors are based on EPA FIRE factors for uncontrolled natural gas combustion with units in lb/MMscf and controlled by SCR wood combustion with units in lb/ton.7 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as define Section 112(b) of the Clean Air Act and are not included in the Total HAPs.8 The hydrogen flouride emissions from wood combustion are based on stack testing results conducted in September 2013 on wood boiler EU007. USEPA AP-42 did not list an emission factor for hydrogen flouride from wood combustion.9 The emission factor for acrolein is based on actual test data from District Energy Center in St. Paul, MN.10 The largest single facility-wide HAP is shown in bold.11 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.

Change in PTE Emissions Due to Test

Burn of Wood Pellets in Boiler #3A

1 Emission factors are based on bark/bark and wet wood fuel, USEPA AP-42, Chapter 1.6 Wood Residue Combustion in Boilers, Tables 1.6-1, 1.6-2, 1.6-3, & 1.6-4, September 2003 unless otherwise noted. Particulate emission rates were divided by two because the amount of ash in the pellet is less than half of what is found in unpelletized wood.

2 The emission factors for some of the speciated organic compounds and trace metals came from background information for USEPA AP-42 Chapter 1.6. Wood residue combustion test data for all pollutants was averaged for all sources that have high efficiency particulate control, as it was assumed that those factors would be most accurately predictive. The emission factors that are based on the background data have shaded cells.

Pollutant EPA Pollutant Type CAS Number

Emission Factors

Emissions From Test Burn

Emission Offset From Replacing Coal with Wood Pellets During Test Burn

Project: Hibbing Public Utilities Prepared: NEESubject: Potential to Emit Calculations Reviewed: Task: Coal Ash to Silo (EU004) Date: July 2015

MPCA Permit Calculation Emission

Factors1Permit Limits

Pollutant gr/dscf gr/dscf lb/hr TPYAssumptions: NOX --- --- --- --- Hours of Operation 8,760 CO --- --- --- --- Exhaust Flow, ft3/min 2,673 VOC --- --- --- --- Exhaust Flow, ft3/hr 160,380 PM 0.002 0.30 6.873 30.11Transfer Rate, TPH 95 PM10 0.002 0.002 0.046 0.20Control Efficiency, % 99% PM2.5 0.002 --- 0.046 0.20

SO2 --- --- --- --- Conversion Factors: Lead --- --- --- --- lb/ton 2,000 CO2e --- --- --- --- gr/dscf to lb/hr 0.00857 CO2 --- --- --- --- hr/yr 8,760 CH4 --- --- --- --- gr/lb 7,000 N2O --- --- --- --- min/hr 60

Potential Emissions as Permitted

Coal Ash to Silo

1 Potential emissions of PM and PM10 based on federally enforceable permit condition contained in Permit No. 13700027-008 issued on January 18, 2012, and expiring January 18, 2017. The permit stipulates an emission limit for PM of 0.30 gr/dscf and PM10 of 0.002 gr/dscf, however the MPCA PTE calculations attached to the permit used 0.002 gr/dscf for the basis of PM, PM10, and PM2.5.

Project: Hibbing Public Utilities Prepared: AMCSubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler #1A (EU001) Date: June 2014

Boiler 1A

Assumptions:

Nat. GasAP-421


CoalAP-424
















CAS Number

Control Efficiency

Permit Limit Boiler 1A and 2A



Proposed


Nat. GasAP-421


CoalAP-424












NOTES:








CAS Number

Control Efficiency





Proposed


Project: Hibbing Public Utilities Prepared: AMCSubject: Potential to Emit Calculations Reviewed: ARDTask: Boiler #2A (EU002) Date: June 2014

Boiler 2A

Assumptions:

Nat. GasAP-421


CoalAP-424
















CAS Number

Control Efficiency




Proposed


Nat. GasAP-421


CoalAP-424












NOTES:








CAS Number

Control Efficiency





Proposed


Project: Hibbing Public Utilities Prepared: CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: High School Boiler #1 (EU005) Date: June 2014

Permit LimitsAP-42

Emission Factors1

Nat. Gas 40 CFR

Part 982,3

lb/MMBtu lb/MMscf lb/MMBtu lb/hr TPYAssumptions: NOX criteria NA --- 100 --- 3.53 15.46

Natural Gas Fired CO criteria NA --- 84.00 --- 2.96 12.99Hours of Operation, Normal Ops 8,760 VOC criteria NA --- 5.50 --- 0.19 0.85Rated Capacity, MMBtu/hr 36 PM4 criteria NA 0.6 7.60 --- 0.27 1.17

PM104 criteria NA --- 7.60 --- 0.27 1.17

Conversion Factors: PM2.54 criteria NA --- 7.60 --- 0.27 1.17

lb/ton 2,000 SO2 criteria NA --- 0.60 --- 0.02 0.09lb/kg 2.204 Lead criteria 7439921 --- 5.00E-04 --- 1.76E-05 7.73E-05CO2 to CO2e 1 CO2e

5 GHG NA --- --- 117.1 4,214 18,459CH4 to CO2e 25 CO2 GHG NA --- --- 116.9 4,210 18,440N2O to CO2e 298 CH4 GHG NA --- --- 0.002 0.08 0.35hr/yr 8,760 N2O GHG NA --- --- 0.0002 0.01 0.03Btu/scf 1,020 Ammonia 6 not classified 7664417 --- 3.2 --- 0.11 0.49min/hr 60 2-Methylnaphthalene HAP (POM) 91576 --- 2.40E-05 --- 8.47E-07 3.71E-06

3-Methylchloranthrene HAP (POM) 56495 --- 1.80E-06 --- 6.35E-08 2.78E-077,12-Dimethylbenz(a)anthracene HAP (POM) 57976 --- 1.60E-05 --- 5.65E-07 2.47E-06

Acenaphthene HAP (POM) 83329 --- 1.80E-06 --- 6.35E-08 2.78E-07Acenaphthylene HAP (POM) 208968 --- 1.80E-06 --- 6.35E-08 2.78E-07

Anthracene HAP (POM) 120127 --- 2.40E-06 --- 8.47E-08 3.71E-07Benz(a)anthracene HAP (POM) 56553 --- 1.80E-06 --- 6.35E-08 2.78E-07

Benzene HAP 71432 --- 2.10E-03 --- 7.41E-05 3.25E-04Benzo(a)pyrene HAP (POM) 50328 --- 1.20E-06 --- 4.24E-08 1.86E-07

Benzo(b)fluoranthene HAP (POM) 205992 --- 1.80E-06 --- 6.35E-08 2.78E-07Benzo(g,h,i)perylene HAP (POM) 191242 --- 1.20E-06 --- 4.24E-08 1.86E-07Benzo(k)fluoranthene HAP (POM) 207089 --- 1.80E-06 --- 6.35E-08 2.78E-07

Butane 7 not classified 106978 --- 2.10E+00 --- 7.41E-02 3.25E-01Chrysene HAP (POM) 218019 --- 1.80E-06 --- 6.35E-08 2.78E-07

Dibenzo(a,h)anthracene HAP (POM) 53703 --- 1.20E-06 --- 4.24E-08 1.86E-07Dichlorobenzene HAP 25321226 --- 1.20E-03 --- 4.24E-05 1.86E-04

Ethane not classified 74840 --- 3.10E+00 --- 1.09E-01 4.79E-01Fluoranthene HAP (POM) 206440 --- 3.00E-06 --- 1.06E-07 4.64E-07

Fluorene HAP (POM) 86737 --- 2.80E-06 --- 9.88E-08 4.33E-07


CAS Number


High School Boiler #1

Permit LimitsAP-42

Emission Factors1

Nat. Gas 40 CFR

Part 982,3

lb/MMBtu lb/MMscf lb/MMBtu lb/hr TPYFormaldehyde HAP 50000 --- 7.50E-02 --- 2.65E-03 1.16E-02

Hexane HAP 110543 --- 1.80E+00 --- 6.35E-02 2.78E-01Indeno(1,2,3-cd)pyrene HAP (POM) 193395 --- 1.80E-06 --- 6.35E-08 2.78E-07

Naphthalene HAP (POM) 91203 --- 6.10E-04 --- 2.15E-05 9.43E-05Pentane not classified 109660 --- 2.60E+00 --- 9.18E-02 4.02E-01

Phenanathrene HAP (POM) 85018 --- 1.70E-05 --- 6.00E-07 2.63E-06Propane not classified 74986 --- 1.60E+00 --- 5.65E-02 2.47E-01Pyrene HAP (POM) 129000 --- 5.00E-06 --- 1.76E-07 7.73E-07Toluene HAP 108883 --- 3.40E-03 --- 1.20E-04 5.26E-04Arsenic HAP 7440382 --- 2.00E-04 --- 7.06E-06 3.09E-05Barium not classified 7440393 --- 4.40E-03 --- 1.55E-04 6.80E-04

Beryllium HAP 7440417 --- 1.20E-05 --- 4.24E-07 1.86E-06Cadmium HAP 7440439 --- 1.10E-03 --- 3.88E-05 1.70E-04Chromium HAP 7440473 --- 1.40E-03 --- 4.94E-05 2.16E-04

Cobalt HAP 7440484 --- 8.40E-05 --- 2.96E-06 1.30E-05Copper not classified 7440508 --- 8.50E-04 --- 3.00E-05 1.31E-04

Manganese HAP 7439965 --- 3.80E-04 --- 1.34E-05 5.87E-05Mercury HAP 7439976 --- 2.60E-04 --- 9.18E-06 4.02E-05

Molybdenum not classified 7439987 --- 1.10E-03 --- 3.88E-05 1.70E-04Nickel HAP 7440020 --- 2.10E-03 --- 7.41E-05 3.25E-04

Selenium HAP 7782492 --- 2.40E-05 --- 8.47E-07 3.71E-06Vanadium not classified 7440622 --- 2.30E-03 --- 8.12E-05 3.56E-04

Zinc not classified 7440666 --- 2.90E-02 --- 1.02E-03 4.48E-03

Total POMs8 HAP NA --- --- --- 2.46E-05 1.08E-04Largest Single HAP (Hexane)9 6.35E-02 2.78E-01

Total HAPs 6.66E-02 2.92E-01

1 Emission factors are based on uncontrolled small boilers (<100 MMBtu/hr), USEPA AP-42, Chapter 1.4 Natural Gas Combustion, Tables 1.4-1, 1.4-2, 1.4-3, & 1.4-4, July 1998.2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (natural gas 53.06 kg CO2/MMBtu), November 29, 2013.3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (CH4 = 0.001 kg CH4/MMBtu and N2O = 0.0001 kg N2O/MMBtu), November 29, 2013.4 PM10 = PM10(filterable) + PM(condensable) = 5.7 + 1.9 = 7.6 lb/MMscf per Table 1.4-2 of AP-42. PM = PM10 = PM2.5 assumed.5 CO2e emissions are based on global warming potential of CO2=1, CH4=25, and N2O=298.6 Ammonia emission factor is based on EPA FIRE factors for uncontrolled natural gas combustion.7 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as define Section 112(b) of the Clean Air Act and are not included in the Total HAPs.8 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.9 Largest single facility-wide HAP is hydrogen chloride (HCl), but natural gas combustion does not emit HCl. The largest single HAP from natural gas combustion is hexane.

Federally Enforceable Permit Limits Permit No. 13700027-008 issued on January 18, 2012, and expiring January 18, 2017.High school boilers (HS1 and HS2) particulate potential emissions are based the AP-42 emission factor for natural gas as opposed to the permit limit for total PM of 0.60 lb/MMBtu.


CAS Number


Project: Hibbing Public Utilities Prepared: CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: High School Boiler #2 (EU006) Date: June 2014

Permit LimitsAP-42

Emission Factors1

Nat. Gas 40 CFR

Part 982,3

lb/MMBtu lb/MMscf lb/MMBtu lb/hr TPYAssumptions: NOX criteria NA --- 100 --- 3.53 15.46

Natural Gas Fired CO criteria NA --- 84.00 --- 2.96 12.99Hours of Operation, Normal Ops 8,760 VOC criteria NA --- 5.50 --- 0.19 0.85Rated Capacity, MMBtu/hr 36 PM4 criteria NA 0.6 7.60 --- 0.27 1.17

PM104 criteria NA --- 7.60 --- 0.27 1.17

Conversion Factors: PM2.54 criteria NA --- 7.60 --- 0.27 1.17

lb/ton 2,000 SO2 criteria NA --- 0.60 --- 0.02 0.09lb/kg 2.204 Lead criteria 7439921 --- 5.00E-04 --- 1.76E-05 7.73E-05CO2 to CO2e 1 CO2e

5 GHG NA --- --- 117.1 4,214 18,459CH4 to CO2e 25 CO2 GHG NA --- --- 116.9 4,210 18,440N2O to CO2e 298 CH4 GHG NA --- --- 0.002 0.08 0.35hr/yr 8,760 N2O GHG NA --- --- 0.0002 0.01 0.03Btu/scf 1,020 Ammonia 6 not classified 7664417 --- 3.2 --- 0.11 0.49min/hr 60 2-Methylnaphthalene HAP (POM) 91576 --- 2.40E-05 --- 8.47E-07 3.71E-06

3-Methylchloranthrene HAP (POM) 56495 --- 1.80E-06 --- 6.35E-08 2.78E-077,12-Dimethylbenz(a)anthracene HAP (POM) 57976 --- 1.60E-05 --- 5.65E-07 2.47E-06

Acenaphthene HAP (POM) 83329 --- 1.80E-06 --- 6.35E-08 2.78E-07Acenaphthylene HAP (POM) 208968 --- 1.80E-06 --- 6.35E-08 2.78E-07

Anthracene HAP (POM) 120127 --- 2.40E-06 --- 8.47E-08 3.71E-07Benz(a)anthracene HAP (POM) 56553 --- 1.80E-06 --- 6.35E-08 2.78E-07

Benzene HAP 71432 --- 2.10E-03 --- 7.41E-05 3.25E-04Benzo(a)pyrene HAP (POM) 50328 --- 1.20E-06 --- 4.24E-08 1.86E-07

Benzo(b)fluoranthene HAP (POM) 205992 --- 1.80E-06 --- 6.35E-08 2.78E-07Benzo(g,h,i)perylene HAP (POM) 191242 --- 1.20E-06 --- 4.24E-08 1.86E-07Benzo(k)fluoranthene HAP (POM) 207089 --- 1.80E-06 --- 6.35E-08 2.78E-07

Butane 7 not classified 106978 --- 2.10E+00 --- 7.41E-02 3.25E-01Chrysene HAP (POM) 218019 --- 1.80E-06 --- 6.35E-08 2.78E-07

Dibenzo(a,h)anthracene HAP (POM) 53703 --- 1.20E-06 --- 4.24E-08 1.86E-07Dichlorobenzene HAP 25321226 --- 1.20E-03 --- 4.24E-05 1.86E-04

Ethane not classified 74840 --- 3.10E+00 --- 1.09E-01 4.79E-01Fluoranthene HAP (POM) 206440 --- 3.00E-06 --- 1.06E-07 4.64E-07

Fluorene HAP (POM) 86737 --- 2.80E-06 --- 9.88E-08 4.33E-07


CAS Number


High School Boiler #2

Permit LimitsAP-42

Emission Factors1

Nat. Gas 40 CFR

Part 982,3

lb/MMBtu lb/MMscf lb/MMBtu lb/hr TPYFormaldehyde HAP 50000 --- 7.50E-02 --- 2.65E-03 1.16E-02

Hexane HAP 110543 --- 1.80E+00 --- 6.35E-02 2.78E-01Indeno(1,2,3-cd)pyrene HAP (POM) 193395 --- 1.80E-06 --- 6.35E-08 2.78E-07

Naphthalene HAP (POM) 91203 --- 6.10E-04 --- 2.15E-05 9.43E-05Pentane not classified 109660 --- 2.60E+00 --- 9.18E-02 4.02E-01

Phenanathrene HAP (POM) 85018 --- 1.70E-05 --- 6.00E-07 2.63E-06Propane not classified 74986 --- 1.60E+00 --- 5.65E-02 2.47E-01Pyrene HAP (POM) 129000 --- 5.00E-06 --- 1.76E-07 7.73E-07Toluene HAP 108883 --- 3.40E-03 --- 1.20E-04 5.26E-04Arsenic HAP 7440382 --- 2.00E-04 --- 7.06E-06 3.09E-05Barium not classified 7440393 --- 4.40E-03 --- 1.55E-04 6.80E-04

Beryllium HAP 7440417 --- 1.20E-05 --- 4.24E-07 1.86E-06Cadmium HAP 7440439 --- 1.10E-03 --- 3.88E-05 1.70E-04Chromium HAP 7440473 --- 1.40E-03 --- 4.94E-05 2.16E-04

Cobalt HAP 7440484 --- 8.40E-05 --- 2.96E-06 1.30E-05Copper not classified 7440508 --- 8.50E-04 --- 3.00E-05 1.31E-04

Manganese HAP 7439965 --- 3.80E-04 --- 1.34E-05 5.87E-05Mercury HAP 7439976 --- 2.60E-04 --- 9.18E-06 4.02E-05

Molybdenum not classified 7439987 --- 1.10E-03 --- 3.88E-05 1.70E-04Nickel HAP 7440020 --- 2.10E-03 --- 7.41E-05 3.25E-04

Selenium HAP 7782492 --- 2.40E-05 --- 8.47E-07 3.71E-06Vanadium not classified 7440622 --- 2.30E-03 --- 8.12E-05 3.56E-04

Zinc not classified 7440666 --- 2.90E-02 --- 1.02E-03 4.48E-03

Total POMs8 HAP NA --- --- --- 2.46E-05 1.08E-04Largest Single HAP (Hexane)9 6.35E-02 2.78E-01

Total HAPs 6.66E-02 2.92E-01

1 Emission factors are based on uncontrolled small boilers (<100 MMBtu/hr), USEPA AP-42, Chapter 1.4 Natural Gas Combustion, Tables 1.4-1, 1.4-2, 1.4-3, & 1.4-4, July 1998.2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (natural gas 53.06 kg CO2/MMBtu), November 29, 2013.3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (CH4 = 0.001 kg CH4/MMBtu and N2O = 0.0001 kg N2O/MMBtu), November 29, 2013.4 PM10 = PM10(filterable) + PM(condensable) = 5.7 + 1.9 = 7.6 lb/MMscf per Table 1.4-2 of AP-42. PM = PM10 = PM2.5 assumed.5 CO2e emissions are based on global warming potential of CO2=1, CH4=25, and N2O=298.6 Ammonia emission factor is based on EPA FIRE factors for uncontrolled natural gas combustion.7 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as define Section 112(b) of the Clean Air Act and are not included in the Total HAPs.8 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.9 Largest single facility-wide HAP is hydrogen chloride (HCl), but natural gas combustion does not emit HCl. The largest single HAP from natural gas combustion is hexane.

Federally Enforceable Permit Limits Permit No. 13700027-008 issued on January 18, 2012, and expiring January 18, 2017.High school boilers (HS1 and HS2) particulate potential emissions are based the AP-42 emission factor for natural gas as opposed to the permit limit for total PM of 0.60 lb/MMBtu.


CAS Number


Project: Hibbing Public Utilities Prepared: AMC/CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: Wood Boiler EU007 Date: June 2014

Assumptions:

Nat. Gas AP-421


WoodAP-424,5


Wood Fired lb/MMBtu lb/MMscf lb/MMBtu lb/MMBtu lb/MMBtu lb/hr TPY lb/hr TPY lb/hr TPY lb/hr TPY lb/hr TPY

Proposed Natural Gas Fired Burner for startup and shut down and for combustion stabilization as necessary. Particulate Matter criteria NA 0.025 7.60 --- 0.577 --- 5.75 21.74 0.67 2.94 4.17 18.27 5.75 21.74 Wood 5.75 21.74

Rated Capacity, MMBtu/hr 230 Particulate Matter < 10 Microns criteria NA 0.025 7.60 --- 0.517 --- 5.75 21.74 0.67 2.94 4.17 18.27 5.75 21.74 Wood 5.75 21.74

Rated Capacity of NG Burner, MMBtu/hr 90 Particulate Matter < 2.5 Microns criteria NA 0.025 7.60 --- 0.447 --- 5.75 21.74 0.67 2.94 4.17 18.27 5.75 21.74 Wood 5.75 21.74

Wood Fuel HHV, Btu/lb 4,430 Sulfur Dioxide criteria NA --- 0.60 --- 0.025 --- 5.75 21.74 0.05 0.23 3.55 15.56 5.75 21.74 Wood 5.75 21.74Wood Fuel HHV, MMBtu/ton 8.86 Nitrogen Oxide criteria NA 0.15 100.00 --- 0.220 --- 34.50 130.41 8.82 38.65 29.82 130.63 34.50 130.63 Combined 34.50 130.63Heating Value of Natural Gas, Btu/scf 1,020 Carbon Monoxide criteria NA 0.58 84.00 --- 0.600 --- 133.40 504.25 7.41 32.46 88.61 388.12 133.40 504.25 Wood 133.40 504.25

Hourly Fuel Rate for Natural Gas, 106 scf/hr 0.09 Volatile Organic Compounds criteria NA --- 5.50 --- 0.017 --- 3.91 14.78 0.49 2.13 2.87 12.55 3.91 14.78 Wood 3.91 14.78

Potential Annual Operating Hours, hr/yr 8,760 Lead criteria 4739921 --- 0.0005 --- 0.00003 --- 0.01 0.03 0.00 0.00 0.00 0.02 0.01 0.03 Wood 0.01 0.03Projected Actual Operation of Gas Burner, hr/yr #REF! CO2e

7 GHG NA --- --- 117.1 --- 209.50 48,184 182,136 10,536 46,147 39,865 174,610 48,184 182,136 Wood 48,184 182,136

Permit Limited Operation for Wood, hr/yr 7,560 CO2 GHG NA --- --- 116.9 --- 206.74 47,549 179,736 10,525 46,099 39,468 172,869 47,549 179,736 Wood 47,549 179,736

Proposed Limited Operation for Wood, hr/yr NA CH4 GHG NA --- --- 0.002 --- 0.0159 3.65 13.80 0.20 0.87 2.42 10.60 3.65 13.80 Wood 3.65 13.80

Maximum Wood Usage, TPH 25.96 N2O GHG NA --- --- 0.0002 --- 0.0079 1.82 6.90 0.02 0.09 1.13 4.95 1.82 6.90 Wood 1.82 6.90

Maximum Wood Usage, TPY 227,404 Ammonia 8,9 not classified 7664417 --- 3.2 --- 0.31 --- 8.05 30.42 0.28 1.24 5.18 22.69 8.05 30.42 Wood 8.05 30.42

Hydrogen Fluoride10 HAP 7664393 --- --- --- 1.60E-03 --- 3.68E-01 1.39 --- --- 2.24E-01 0.98 0.37 1.39 Wood 0.37 1.39

Conversion Factors: 1,1,1-Trichloroethane (methyl chloroform) HAP 71556 --- --- --- 3.10E-05 --- 7.13E-03 0.03 --- --- 4.34E-03 0.02 7.13E-03 2.70E-02 Wood 0.01 0.03lb/ton 2,000 1,2-Dichloroethane (ethyldene dichloride) HAP 107062 --- --- --- 2.90E-05 --- 6.67E-03 0.03 --- --- 4.06E-03 0.02 6.67E-03 2.52E-02 Wood 0.01 0.03lb/kg 2.204 1,2-Dichloropropane (propylene dichloride) HAP 78875 --- --- --- 3.30E-05 --- 7.59E-03 0.03 --- --- 4.62E-03 0.02 7.59E-03 2.87E-02 Wood 0.01 0.03CO2 to CO2e 1 2,3,7,8-TCDD HAP (POM) 1746016 --- --- --- 1.06E-11 --- 2.44E-09 0.00 --- --- 1.48E-09 0.00 2.44E-09 9.22E-09 Wood 2.44E-09 9.22E-09CH4 to CO2e 25 2,3,7,8-TCDF HAP (POM) 51207319 --- --- --- 5.05E-11 --- 1.16E-08 0.00 --- --- 7.07E-09 0.00 1.16E-08 4.39E-08 Wood 1.16E-08 4.39E-08N2O to CO2e 298 2,4,6-Trichlorophenol HAP 88062 --- --- --- 1.14E-08 --- 2.62E-06 0.00 --- --- 1.60E-06 0.00 2.62E-06 9.91E-06 Wood 2.62E-06 9.91E-06Boiler HP to Btu/hr 33,446 2,4-Dinitrophenol HAP 51285 --- --- --- 9.33E-08 --- 2.15E-05 0.00 --- --- 1.31E-05 0.00 2.15E-05 8.11E-05 Wood 2.15E-05 8.11E-05Btu/MMBtu 1,000,000 2-Methylnaphthalene HAP (POM) 91576 --- 2.40E-05 --- 1.60E-07 --- 3.68E-05 0.00 2.12E-06 9.28E-06 2.45E-05 0.00 3.68E-05 1.39E-04 Wood 3.68E-05 1.39E-04hr/yr 8,760 3-Methylchloranthrene HAP (POM) 56495 --- 1.80E-06 --- --- --- --- --- 1.59E-07 6.96E-07 1.59E-07 0.00 1.59E-07 6.96E-07 Natural Gas 1.59E-07 6.96E-07

Btu/scf (natural gas) 1,020 7,12-Dimethylbenz(a)anthracene HAP (POM) 57976 --- 1.60E-05 --- --- --- --- --- 1.41E-06 6.18E-06 1.41E-06 0.00 1.41E-06 6.18E-06 Natural Gas 1.41E-06 6.18E-06min/hr 60 4-Nitrophenol HAP 100027 --- --- --- 1.71E-07 --- 3.93E-05 0.00 --- --- 2.39E-05 0.00 3.93E-05 1.49E-04 Wood 3.93E-05 1.49E-04

Acenaphthene HAP (POM) 83329 --- 1.80E-06 --- 6.29E-09 --- 1.45E-06 0.00 1.59E-07 6.96E-07 1.04E-06 0.00 1.45E-06 5.47E-06 Wood 1.45E-06 5.47E-06Acenaphthylene HAP (POM) 208968 --- 1.80E-06 --- 1.28E-06 --- 2.94E-04 0.00 1.59E-07 6.96E-07 1.79E-04 0.00 2.94E-04 1.11E-03 Wood 2.94E-04 1.11E-03

Acetaldehyde HAP 75070 --- --- --- 2.34E-04 --- 5.38E-02 0.20 --- --- 3.28E-02 0.14 5.38E-02 2.03E-01 Wood 5.38E-02 2.03E-01Acetophenone HAP 98862 --- --- --- 3.20E-09 --- 7.36E-07 0.00 --- --- 4.48E-07 0.00 7.36E-07 2.78E-06 Wood 7.36E-07 2.78E-06

Acrolein11 HAP 107028 --- --- --- 4.36E-05 --- 1.00E-02 0.04 --- --- 6.10E-03 0.03 1.00E-02 3.79E-02 Wood 1.00E-02 3.79E-02Anthracene HAP (POM) 120127 --- 2.40E-06 --- 4.17E-08 --- 9.59E-06 0.00 2.12E-07 9.28E-07 6.05E-06 0.00 9.59E-06 3.63E-05 Wood 9.59E-06 3.63E-05Antimony HAP 7440360 --- --- --- 1.17E-05 --- 2.69E-03 0.01 --- --- 1.64E-03 0.01 2.69E-03 1.02E-02 Wood 2.69E-03 1.02E-02Arsenic HAP 7440382 --- 2.00E-04 --- 3.25E-05 --- 7.48E-03 0.03 1.76E-05 7.73E-05 4.57E-03 0.02 7.48E-03 2.83E-02 Wood 7.48E-03 2.83E-02Barium not classified 7440393 --- 4.40E-03 --- 1.70E-04 --- 3.91E-02 0.15 3.88E-04 1.70E-03 2.42E-02 0.11 0.04 0.15 Wood 3.91E-02 1.48E-01

Benzene HAP 71432 --- 2.10E-03 --- 7.10E-04 --- 1.63E-01 0.62 1.85E-04 8.12E-04 9.96E-02 0.44 0.16 0.62 Wood 1.63E-01 6.17E-01Benzo(a)anthracene HAP (POM) 56553 --- 1.80E-06 --- 6.50E-08 --- 1.50E-05 0.00 1.59E-07 6.96E-07 9.26E-06 4.06E-05 1.50E-05 5.65E-05 Wood 1.50E-05 5.65E-05

Benzo(a)pyrene HAP (POM) 50328 --- 1.20E-06 --- 2.60E-06 --- 5.98E-04 0.00 1.06E-07 4.64E-07 3.64E-04 1.59E-03 5.98E-04 2.26E-03 Wood 5.98E-04 2.26E-03Benzo(b)fluoranthene HAP (POM) 205992 --- 1.80E-06 --- 1.00E-07 --- 2.30E-05 0.00 1.59E-07 6.96E-07 1.42E-05 6.20E-05 2.30E-05 8.69E-05 Wood 2.30E-05 8.69E-05Benzo(g,h,i)perylene HAP (POM) 191242 --- 1.20E-06 --- 9.30E-08 --- 2.14E-05 0.00 1.06E-07 4.64E-07 1.31E-05 5.75E-05 2.14E-05 8.09E-05 Wood 2.14E-05 8.09E-05Benzo(k)fluoranthene HAP (POM) 207089 --- 1.80E-06 --- 3.60E-08 --- 8.28E-06 0.00 1.59E-07 6.96E-07 5.20E-06 2.28E-05 8.28E-06 3.13E-05 Wood 8.28E-06 3.13E-05

Beryllium HAP 7440417 --- 1.20E-05 --- 1.78E-06 --- 4.09E-04 0.00 1.06E-06 4.64E-06 2.50E-04 1.10E-03 4.09E-04 1.55E-03 Wood 4.09E-04 1.55E-03bis(2-Ehtylhexyl)phthalate (DEHP) HAP 117817 --- --- --- 4.70E-08 --- 1.08E-05 0.00 --- --- 6.58E-06 2.88E-05 1.08E-05 4.09E-05 Wood 1.08E-05 4.09E-05

Bromomethane HAP 74839 --- --- --- 1.50E-05 --- 3.45E-03 0.01 --- --- 2.10E-03 9.20E-03 3.45E-03 1.30E-02 Wood 3.45E-03 1.30E-02Butane not classified 106978 --- 2.10E+00 --- --- --- --- --- 1.85E-01 0.81 1.85E-01 0.81 0.19 0.81 Natural Gas 1.85E-01 8.12E-01

Cadmium HAP 7440439 --- 1.10E-03 --- 1.80E-06 --- 4.14E-04 0.00 9.71E-05 4.25E-04 3.49E-04 1.53E-03 4.14E-04 1.56E-03 Wood 4.14E-04 1.56E-03Carbon Tetrachloride HAP 56235 --- --- --- 4.50E-05 --- 1.04E-02 0.04 --- --- 6.30E-03 0.03 0.01 0.04 Wood 0.01 0.04

Chlorine HAP 7782505 --- --- --- 7.90E-04 --- 1.82E-01 0.69 --- --- 1.11E-01 0.48 0.18 0.69 Wood 0.18 0.69Chlorobenzene HAP 108907 --- --- --- 3.30E-05 --- 7.59E-03 0.03 --- --- 4.62E-03 0.02 0.01 0.03 Wood 0.01 0.03

Chloroform HAP 67663 --- --- --- 2.80E-05 --- 6.44E-03 0.02 --- --- 3.92E-03 0.02 0.01 0.02 Wood 0.01 0.02Methyl Chloride (Chloromethane) HAP 74873 --- --- --- 2.30E-05 --- 5.29E-03 0.02 --- --- 3.22E-03 0.01 0.01 0.02 Wood 0.01 0.02

Chromium HAP 7440473 --- 1.40E-03 --- 1.46E-06 --- 3.36E-04 0.00 1.24E-04 0.00 3.28E-04 1.44E-03 3.36E-04 1.44E-03 Combined 3.36E-04 1.44E-03Chromium (VI) HAP 18540292 --- --- --- 1.63E-06 --- 3.75E-04 0.00 --- --- 2.28E-04 1.00E-03 3.75E-04 1.42E-03 Wood 3.75E-04 1.42E-03

Chrysene HAP (POM) 218019 --- 1.80E-06 --- 2.64E-09 --- 6.07E-07 0.00 1.59E-07 0.00 5.28E-07 2.31E-06 6.07E-07 2.31E-06 Combined 6.07E-07 2.31E-06Cobalt HAP 7440484 --- 8.40E-05 --- 3.54E-07 --- 8.14E-05 0.00 7.41E-06 0.00 5.70E-05 2.50E-04 8.14E-05 3.08E-04 Wood 8.14E-05 3.08E-04Copper not classified 7440508 --- 8.50E-04 --- 4.90E-05 --- 1.13E-02 0.04 7.50E-05 0.00 6.94E-03 3.04E-02 1.13E-02 4.26E-02 Wood 0.01 0.04

Dibenzo(a,h)anthracene HAP (POM) 53703 --- 1.20E-06 --- 9.10E-09 --- 2.09E-06 0.00 1.06E-07 0.00 1.38E-06 6.04E-06 2.09E-06 7.91E-06 Wood 2.09E-06 7.91E-06Dichlorobenzene HAP 25321226 --- 1.20E-03 --- --- --- --- --- 1.06E-04 0.00 1.06E-04 4.64E-04 1.06E-04 4.64E-04 Natural Gas 1.06E-04 4.64E-04

Dichloromethane (methylene chloride) HAP 75092 --- --- --- 2.90E-04 --- 6.67E-02 0.25 --- --- 4.06E-02 0.18 0.07 0.25 Wood 0.07 0.25

Permit Limits

Wood Boiler


CAS Number

Worst-Case Fuel Type For TPY

Emissions

PTE with Nat. Gas Burner (8,760 hours) and Wood

Combustion (7,560 hours)Wood Nat. Gas

Wood at 150 MMBtu and Nat. Gas at 90 MMBtu6

Emission Factors Potential Emissions as Permitted (7,560 hours)

Potential Emissions from Burner (8,760

hours)

Combined Emission Rate

Worst-Case Fuel

Nat. Gas AP-421


WoodAP-424,5


lb/MMBtu lb/MMscf lb/MMBtu lb/MMBtu lb/MMBtu lb/hr TPY lb/hr TPY lb/hr TPY lb/hr TPY lb/hr TPY

Ethane not classified 74840 --- 3.10E+00 --- --- --- --- --- 2.74E-01 1.20 2.74E-01 1.20 0.27 1.20 Natural Gas 0.27 1.20

Ethyl benzene HAP 100414 --- --- --- 3.10E-05 --- 7.13E-03 0.03 --- --- 4.34E-03 0.02 0.01 0.03 Wood 0.01 0.03Fluoranthene HAP (POM) 206440 --- 3.00E-06 --- 1.60E-06 --- 3.68E-04 0.00 2.65E-07 1.16E-06 2.24E-04 9.82E-04 3.68E-04 1.39E-03 Wood 3.68E-04 1.39E-03

Fluorene HAP (POM) 86737 --- 2.80E-06 --- 3.40E-06 --- 7.82E-04 0.00 2.47E-07 1.08E-06 4.76E-04 2.09E-03 7.82E-04 2.96E-03 Wood 7.82E-04 2.96E-03Formaldehyde HAP 50000 --- 7.50E-02 --- 1.40E-03 --- 3.22E-01 1.22 6.62E-03 2.90E-02 2.03E-01 0.89 0.32 1.22 Wood 0.32 1.22

Hexane HAP 110543 --- 1.80E+00 --- --- --- --- --- 1.59E-01 6.96E-01 1.59E-01 0.70 0.16 0.70 Natural Gas 0.16 0.70

Hydrogen Chloride12 HAP 7647010 --- --- --- 1.90E-02 --- 4.37 16.52 --- --- 2.66 11.65 4.37 16.52 Wood 4.37 16.52Indeno(1,2,3-cd)pyrene HAP (POM) 193395 --- 1.80E-06 --- 8.70E-08 --- 2.00E-05 0.00 1.59E-07 0.00 1.23E-05 5.40E-05 2.00E-05 7.56E-05 Wood 2.00E-05 7.56E-05

Manganese HAP 7439965 --- 3.80E-04 --- 1.30E-03 --- 2.99E-01 1.13 3.35E-05 0.00 1.82E-01 0.80 0.30 1.13 Wood 0.30 1.13Mercury HAP 7439976 --- 2.60E-04 --- 3.50E-06 --- 8.05E-04 0.00 2.29E-05 0.00 5.13E-04 2.25E-03 8.05E-04 3.04E-03 Wood 8.05E-04 3.04E-03

Molybdenum not classified 7439987 --- 1.10E-03 --- 2.10E-06 --- 4.83E-04 0.00 9.71E-05 0.00 3.91E-04 1.71E-03 4.83E-04 1.83E-03 Wood 4.83E-04 1.83E-03

Naphthalene HAP (POM) 91203 --- 6.10E-04 --- 6.82E-05 --- 1.57E-02 0.06 5.38E-05 0.00 9.60E-03 0.04 0.02 0.06 Wood 0.02 0.06Nickel HAP 7440020 --- 2.10E-03 --- 2.27E-06 --- 5.22E-04 0.00 1.85E-04 0.00 5.03E-04 2.20E-03 5.22E-04 2.20E-03 Combined 5.22E-04 2.20E-03

Pentane not classified 109660 --- 2.60E+00 --- --- --- --- --- 2.29E-01 1.00 2.29E-01 1.00 0.23 1.00 Natural Gas 0.23 1.00

Phenanthrene HAP (POM) 85018 --- 1.70E-05 --- 1.36E-06 --- 3.13E-04 0.00 1.50E-06 0.00 1.92E-04 8.41E-04 3.13E-04 1.18E-03 Wood 3.13E-04 1.18E-03Phenol HAP 108952 --- --- --- 1.25E-05 --- 2.88E-03 0.01 --- --- 1.75E-03 7.67E-03 2.88E-03 1.09E-02 Wood 2.88E-03 1.09E-02

Phosphorus HAP 7723140 --- --- --- 1.93E-05 --- 4.44E-03 0.02 --- --- 2.70E-03 1.18E-02 4.44E-03 1.68E-02 Wood 4.44E-03 1.68E-02Propane not classified 74986 --- 1.60E+00 --- --- --- --- --- 1.41E-01 0.62 1.41E-01 0.62 0.14 0.62 Natural Gas 0.14 0.62

Propionaldehyde HAP 123386 --- --- --- 6.10E-05 --- 1.40E-02 0.05 --- --- 8.54E-03 0.04 0.01 0.05 Wood 0.01 0.05Selenium HAP 7782492 --- 2.40E-05 --- 2.44E-06 --- 5.61E-04 0.00 2.12E-06 0.00 3.44E-04 1.51E-03 5.61E-04 2.12E-03 Wood 5.61E-04 2.12E-03Styrene HAP 100425 --- --- --- 1.90E-03 --- 4.37E-01 1.65 --- --- 2.66E-01 1.17 0.44 1.65 Wood 0.44 1.65Toluene HAP 108883 --- 3.40E-03 --- 2.13E-05 --- 4.90E-03 0.02 3.00E-04 0.00 3.28E-03 1.44E-02 4.90E-03 1.85E-02 Wood 4.90E-03 1.85E-02

Vinyl Chloride HAP 75014 --- --- --- 1.80E-05 --- 4.14E-03 0.02 --- --- 2.52E-03 1.10E-02 4.14E-03 1.56E-02 Wood 4.14E-03 1.56E-02Xylenes HAP 1330207 --- --- --- 2.50E-05 --- 5.75E-03 0.02 --- --- 3.50E-03 1.53E-02 5.75E-03 2.17E-02 Wood 5.75E-03 2.17E-02

Zinc not classified 7440666 --- 2.90E-02 --- 4.20E-04 --- 9.66E-02 0.37 2.56E-03 0.01 6.14E-02 2.69E-01 9.66E-02 3.65E-01 Wood 9.66E-02 3.65E-01

Total POMs13 HAP NA --- --- --- --- --- 1.82E-02 6.87E-02 6.12E-05 2.68E-04 1.11E-02 4.87E-02 0.02 0.07 Wood 1.82E-02 6.87E-02Largest Single HAP 4.37 16.52

Total HAPs 6.56 24.89

1 Emission factors are based on uncontrolled small boilers (<100 MMBtu/hr), USEPA AP-42, Chapter 1.4 Natural Gas Combustion, Tables 1.4-1, 1.4-2, 1.4-3, & 1.4-4, July 1998.2 CO2 emission factor from 40 CFR 98 Subpart C, Table C-1 (natural gas 53.06 kg CO2/MMBtu and wood 93.80 kg CO2/MMBtu), November 29, 2013.

3 CH4 and N2O emission factors from 40 CFR 98 Subpart C, Table C-2 (natural gas CH4 = 0.001 kg CH4/MMBtu and N2O = 0.0001 kg N2O/MMBtu and wood CH4 = 0.0072 kg CH4/MMBtu and N2O 0.0036 kg N2O/MMBtu), November 29, 2013.

4 Emission factors are based on bark/bark and wet wood fuel, USEPA AP-42, Chapter 1.6 Wood Residue Combustion in Boilers, Tables 1.6-1, 1.6-2, 1.6-3, & 1.6-4, September 2003 unless otherwise noted.

6 The boiler is not capable of operating at full capacity for both the wood burner and the natural gas burner together. Emissions are based on the natural gas burner at full capacity and the wood burner at maximum capacity minus the capacity of the natural gas burner.

7 CO2e emissions are based on global warming potential of CO2=1, CH4=25, and N2O=298.8 Ammonia emission factors are based on EPA FIRE factors for uncontrolled natural gas combustion with units in lb/MMscf and controlled by SCR wood combustion with units in lb/ton.9 Pollutants listed in italics have listed emission factors in USEPA AP-42, but are not HAPs as define Section 112(b) of the Clean Air Act and are not included in the Total HAPs.10 The hydrogen flouride emissions from wood combustion are based on stack testing results conducted in September 2013. USEPA AP-42 did not list an emission factor for hydrogen flouride from wood combustion.11 The emission factor for acrolein is based on actual test data from District Energy Center in St. Paul, MN.12 The largest single facility-wide HAP is shown in bold.13 Individual polycyclic organic matter (POMs) are listed separately, but only counted in the Total HAPs as Total POMs.

Permit Limits

5 The emission factors for some of the speciated organic compounds and trace metals came from background information for USEPA AP-42 Chapter 1.6. Wood residue combustion test data for all pollutants was averaged for all sources that have high efficiency particulate control, as it was assumed that those factors would be most accurately predictive of potential emissions from the wood-fired boilers. Some of the facilties tested had no control, cyclone control, or wet scrubbers, and data from those facilities was not used in developing average emission factors. In addition to not being similarly controlled, those boilers are most likely older than the better controlled boilers, and hence may be less efficient in relation to combustion (From the TSD for Permit Action-005, where the wood boiler was initially permitted). The emission factors that are based on the background data have shaded cells.

Proposed PTE with Nat. Gas Burner (8,760 hours) and Wood Combustion (7,560

hours)Wood Nat. Gas

Wood at 150 MMBtu and Nat. Gas at 90 MMBtu6


Proposed Emissions from Burner (8,760

hours)

Combined Emission Rate

Worst-Case Fuel

Worst-Case Fuel TypePollutant EPA Pollutant

TypeCAS

Number

Project: Hibbing Public Utilities Emissions Inventory Prepared: ASubject: Potential to Emit Calculations ReviewTask: Wood and Wood Ash Handling EU008, EU010, and EU011 Date: J

EmissionFactor2

lb/ton lb/hr TPY lb/hr TPY lb/hrAssumptions: PM 0.01 2.00 8.76 0.02 0.09 0.60

Hours of Operation 8,760 PM10 0.01 2.00 8.76 0.14 0.61 0.60Baghouse Control Efficiency, PM 99% PM2.5 0.01 2.00 8.76 0.14 0.61 0.60Baghouse Control Efficiency, PM10 and PM2.5 93% PM 0.01 0.50 2.19 0.01 0.02 0.06Enclosed Wood Unloading Throughput, tons/hr 200 PM10 0.01 0.50 2.19 0.04 0.15 0.06Wood Conveyor Throughput, tons/hr 50 PM2.5 0.01 0.50 2.19 0.04 0.15 0.06Wood Metering Bin Throughput, tons/hr 50 PM 0.01 0.50 2.19 0.01 0.02 0.03Enclosed Wood Unloading Exhaust Flow, ft3/min 35,000 PM10 0.01 0.50 2.19 0.04 0.15 0.03Wood Conveyor Exhaust Flow, ft3/min 3,500 PM2.5 0.01 0.50 2.19 0.04 0.15 0.03Wood Metering Exhaust Flow, ft3/min 1,800Outlet Concentration, gr/dscf 0.002Maximum Wood Throughput, TPY1 227,404

Conversion Factors:lb/ton 2,000gr/dscf to lb/hr 0.008571hr/yr 8,760gr/lb 7,000min/hr 60

1 Maximum wood throughput is not based on the capacity of the wood handling system but on the capacity of the boiler assuming a HHV of wood of 8.86 MMBtu/ton.

PoteEmissi

PermWood Handling

Enclosed Wood Unloading Area (EU008)

Wood Conveyor (EU010)

Wood Transfer/Metering Bin (EU011)

2 Emission factors shown were taken from the MPCA PTE calculations attached to air emission Permit No. 13700027-008. The calculations contain no reference citation for the emission factor; however the grain loading is the federally enforceable permit limit for the wood handling systems.

Emission Sources PollutantUncontrolled

EmissionControlled Emission

AMC/CWBwed: ARDJune 2014

TPY2.632.632.630.260.260.260.140.140.14

ential ons as

mitted

Project: Hibbing Public Utilities Emissions Inventory Prepared: AMC/CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: Cooling Tower (formerly EU014 reclassified as insignificant activity (IA)) Date: June 2014

PTE Hourly Emissions Per Tower

PTE Annual Emissions Per Tower

Cooling Towers PTE Hourly Emissions

Cooling Towers PTE Annual Emissions

Cooling Tower lb/hr TPY lb/hr TPYAssumptions: NOX --- --- --- ---

Hours of Operation 8,760 CO --- --- --- --- Circulating Flow Rate, gal/min each tower (Manufacturer Spec.) 18,000 VOC --- --- --- --- Circulating Flow Rate, gal/hr each tower 1,080,000 PM 2.05 8.99 4.10 17.98Total Dissolved Solids (TDS) Concentration, ppm 1,200 PM10 1.56 6.83 3.12 13.66PM Emission Factor, lb/1000 gal1,2 0.0019 PM2.5 1.56 6.83 3.12 13.66Fraction Representing PM10 and PM2.5

3 76% SO2 --- --- --- --- Number of Towers 2 Lead --- --- --- ---

CO2e --- --- --- --- Conversion Factors: CO2 --- --- --- ---

lb/ton 2,000 CH4 --- --- --- --- hr/yr 8,760 N2O --- --- --- ---

1 Emission factor is based on induced draft tower, USEPA AP-42, Chapter 13.4 Wet Cooling Towers, Table 13.4-1, January 1995.

Description Stack ID Height (ft)

Diameter (ft)

Temperature (°F) ACFM

PM10 Emission Rate (lb/hr)

West Tower Cell 1 SV015 31.33 18 100 557,578 0.39West Tower Cell 2 SV016 31.33 18 100 557,578 0.39East Tower Cell 1 SV017 39.4 18 100 498,819 0.39East Tower Cell 2 SV018 39.4 18 100 498,819 0.39

Pollutant

2 The emission factor of 0.019 lb PM/1000 gal is representative of a TDS=12,000 ppm (Table 13.4-1,note c), HPU's TDS levels are less than 1,200 ppm so the emission factor was adjusted accordingly.3 PM10 / PM2.5 emissions are estimated to be 76% of total PM emissions, as presented in "Calculating Realistic PM10 Emissions from Cooling Towers," by Joel Reisman & Gordon Frisbie, Environmental Progress, Vol. 21, No. 2, Pg. 127-130, 2002 (Figure 1). (http://www.energy.ca.gov/sitingcases/palomar/documents/applicants_files/Data_Request_Response/Air%20Quality/Attachment%204-1.pdf)

Project: Hibbing Public Utilities Emissions Inventory Prepared: AMC/CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: Haul Roads FS002 Date: June 2014

Haul Roads Calculated Emission Factors

Assumptions:Wood

Receiving

Wood Ash Loadout Trucks

Coal Receiving

Coal to Pit

From Coal Pit

Coal Ash Loadout

Wood Receiving Truck Distance Traveled, mi 0.01 1.073 1.360 1.360 2.080 0.647 1.360Quantity Transported per Truck, tons 23 0.215 0.272 0.272 0.416 0.129 0.272Trips per day 40 0.053 0.067 0.067 0.102 0.032 0.067

Wood Ash Truck Distance Traveled, mi 0.03 0% 0% 0% 0% 0% 0%

Quantity Transported per Truck, tons 29

Trips per day 2 Calculated Uncontrolled Emissions Unlimited Annual Emissions (TPY)

Coal Receiving Distance Traveled, mi 0.04 207.8 28.2 388.6 73.3 10.3 14.1 0.36Quantity Transported per Truck, tons 29 41.6 5.6 77.7 14.7 2.1 2.8 0.07Trips per day 21 10.2 1.4 19.1 3.6 0.5 0.7 0.02Coal to Pit Distance Traveled, mi 0.10

Quantity Transported per Truck, tons 44 Calculated Controlled Emissions PTE Emissions (TPY)

Trips per day 1 207.8 28.2 388.6 73.3 10.3 14.1 0.36From Coal Pit Distance Traveled, mi 0.04 41.6 5.6 77.7 14.7 2.1 2.8 0.07Quantity Transported per Truck, tons 14 10.2 1.4 19.1 3.6 0.5 0.7 0.02Trips per day 1Coal Ash Distance Traveled, mi 0.03Quantity Transported per Truck, tons 29Trips per day 1

Annual Number of Wood Receiving Trucks 14,600Annual Number of Wood Ash Trucks 730Annual Number of Coal Receiving Trucks 7,665Annual Number of Coal to Pit Trucks 365Annual Number of From Coal Pit Trucks 365Annual Number of Coal Ash Trucks 365

Annual Mileage of Wood Receiving Trucks 194Annual Mileage of Wood Ash Trucks 21Annual Mileage of Coal Receiving Trucks 286Annual Mileage of Coal to Pit Trucks 35Annual Mileage of From Coal Pit Trucks 16Annual Mileage of Coal Ash Trucks 10

Annual Mileage, VMT/yr 562Average Daily Traffic 66Hours of Operation 8,760

AP-42, Section 13.2.1 Emission Factor CalculationE= k * (sL)^a * (W)^b * (1-P/4N)

Constant, k (PM), lb/VMT 0.011Constant, k (PM10), lb/VMT 0.0022Constant, k (PM2.5), lb/VMT 0.00054

Silt Content of Road Surface1, sL, g/m2 5Empirical Constant, a 0.91

Mean Vehicle Weight, W, tonsEmpirical Constant, b 1.02

Number of Wet Days (0.01" precip), P 115Number of Days per Year, N 365

Conversion Factorslb/tons 2,000

1 Silt content of road surface is based on ubiquitous baseline value for roads with < 500 average daily traffic, AP-42 Chapter 13.2.1 Paved Roads, Table 13.2.1-2, January 2011.

PM, lb/yr

Emission Factor, E (PM), lb/VMTEmission Factor, E (PM10), lb/VMTEmission Factor, E (PM2.5), lb/VMT

Road Washing and Sweeping Percent Control, %

PM10, lb/yrPM2.5, lb/yr

PM, lb/yrPM10, lb/yrPM2.5, lb/yr

Project: Hibbing Public Utilities Emissions Inventory Prepared: AMC/CWBSubject: Potential to Emit Calculations Reviewed: ARDTask: Fugitive Dust Sources Date: June 2014

where, where,E=emission factor, lb/ton E=emission factor, lb/tonk=particle size multiplier k=particle size multiplierk=0.74 for PM k=0.74 for PMk=0.35 for PM10 k=0.35 for PM10

k=0.053 for PM2.5 k=0.053 for PM2.5

u=mean wind speed, mph (12 used) u=mean wind speed, mph (12 used)M=material moisture content (27.3% from proximate analysis) M=material moisture content (10% estimate w/ wetting of ash)

PM Emission Factor: 0.00019 lb/ton PM Emission Factor: 0.00078 lb/tonPM10 Emission Factor: 0.00009 lb/ton PM10 Emission Factor: 0.00037 lb/tonPM2.5 Emission Factor: 0.00001 lb/ton PM2.5 Emission Factor: 0.00006 lb/ton

Capacity Capacity PM PM10 PM2.5 PM PM10 PM2.5

ID Source Description tons/hr TPY lb/ton lb/ton lb/ton % % % lb/hr TPY lb/hr TPY lb/hr TPY ControlIA (FS001) Coal Unloading1 50 438,000 1.90E-04 9.00E-05 1.36E-05 0% 0% 0% 9.52E-03 4.17E-02 4.50E-03 1.97E-02 6.82E-04 2.99E-03 EnclosureFS003 Coal Ash Loadout2 50 35,040 7.76E-04 3.67E-04 5.56E-05 0% 0% 0% 3.88E-02 1.36E-02 1.84E-02 6.43E-03 2.78E-03 9.74E-04 WettingFS004 Wood Ash Loadout3 30 5,500 7.76E-04 3.67E-04 5.56E-05 0% 0% 0% 2.33E-02 2.14E-03 1.10E-02 1.01E-03 1.67E-03 1.53E-04 WettingIA (FS005) Coal Pit Dumping4 240 350,400 1.90E-04 9.00E-05 1.36E-05 0% 0% 0% 4.57E-02 3.33E-02 2.16E-02 1.58E-02 3.27E-03 2.39E-03 N/AIA Reserve Pile 140,077 1.90E-04 9.00E-05 1.36E-05 0% 80% 0% 0.00E+00 1.33E-02 0.00E+00 1.26E-03 0.00E+00 9.55E-04

TOTAL 1.17E-01 9.08E-02 5.55E-02 4.29E-02 8.40E-03 6.50E-03IA = insignificant activity

4 Coal pit dumping annual capacity is based on the maximum amount of coal Boilers 1A, 2A, and 3A can combust. FS005 was reclassified as an insignificant source with permit action 008.5 The reserve pile has a listed capacity in the MPCA permit calculations of 140,077 tons per year and a listed control efficiency for PM10 of 80 percent.

1 The annual maximum capacity of the coal unloading to enclosed storage is based on the maximum hourly capacity multiplied by total hours in a year (8,760) since nothing prevents more coal being stored in a given year than what can be combusted. FS001 was reclassified as an insignificant source with permit action 008.2 Coal ash loadout is based on the maximum amount of coal that can be combusted in boilers 1A, 2A, and 3A multiplied by a factor for the amount of ash in coal. Based on a study performed by the Indiana Center for Coal Technology Research, Coal Characteristics , dated October 2008, sub-bituminous coal can be expected to have an ash content of less than 10% by weight. Testing at Virginia Public Utilities which uses the same coal as Hibbing Public Utilities indicates that the ash content of the coal as received is 5.2% by weight. For calculation purposes an ash content of 10% by weight was used to determine the maximum annual coal ash to be loaded out.3 Maximum amount of wood ash generated is based on the annual wood throughput and an ash percent by weight of 2 percent. The annual wood ash throughput based on the HHV of wood would be 4,548 TPY; however, the HHV fluctuates so for calculation of wood ash loadout, the annual capacity of ash assumed for calculation purposes is 5,500 TPY. The 5,500 TPY value corresponds to the annual capacity used in the MPCA emission calculation tables.

Coal Dumping (drop equation, AP-42 Section 13.2.4, Nov. 2006) Ash Dumping (drop equation, AP-42 Section 13.2.4, Nov. 2006)

Emission Factor Control Efficiency Controlled EmissionsPM PM10 PM2.5

])2//()5/[(*)0032.0( 4.13.1 MukE ])2//()5/[(*)0032.0( 4.13.1 MukE

Attachment 2. Points calculator

1) AQ Facility ID No.: 1145 (AI) Total Points 45

2) Facility Name: Hibbing Public Utilities Commision

3) Small business? y/n? n

4) DQ Numbers (including all rolled) : 5323

5) Date of each Application Received: 7/31/2015

6) Final Permit No. 13700027-010

7) Permit Staff Eric Sulita

8) "Work completed" in which .xls file (i.e. unit 2b, unit 1a, biofuels)?

Total

Application Type DQ No. Qty. Points Points Details

Administrative Amendment 1 0

Minor Amendment 4 0

Applicability Request 10 0

Moderate Amendment 15 0

Major Amendment 5323 1 25 25

Individual State Permit (not reissuance) 50 0

Individual Part 70 Permit (not reissuance) 75 0

Additional Points

Modeling Review 15 0

BACT Review 15 0

LAER Review 15 0

CAIR/Part 75 CEM analysis 10 0

NSPS Review 10 0

NESHAP Review 5323 1 10 10

Case-by-case MACT Review 20 0

Netting 10 0

Limits to remain below threshold 5323 1 10 10

Plantwide Applicability Limit (PAL) 20 0

AERA review 15 0

Variance request under 7000.7000 35 0

Confidentiality request under 7000.1300 2 0

EAW review

Part 4410.4300, subparts 18, item A; and 29 15 0

Part 4410.4300, subparts 8, items A & B; 10, items A to C; 16, items A & D; 17, items A to C & E to G; and 18, items B & C

35 0

Part 4410.4300, subparts 4; 5 items A & B; 13; 15; 16, items B & C; and 17 item D

70 0

Add'l Points 20

subp. DDDDD

NSR Major modification

technical support document draft air emission permit no ... tsd_0.pdf · system and boiler...

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