DTE Electric Company Belle River Combined Cycle Power Plant

Transcription

1 DTE Electric Company Belle River Combined Cycle Power Plant RESPONSE TO COMMENTS DOCUMENT PERMIT No Rick Snyder, Governor Air Quality Division Michigan Department of Environmental Quality INTERNET: Mary Ann Dolehanty, Director Air Quality Division Constitution Hall, 2 nd Floor, South Tower 525 West Allegan Street P.O. Box Lansing, Michigan Phone: Fax:

2 Response to s Document Page 1 of 13 Table of Contents Section Page Public Participation Process... 2 Summary of s Resulting in Changes to the Permit... 3 Summary of Significant s... 5 Alternative Technologies... 5 Dispersion Modeling... 6 Facility Emissions, Greenhouse Gases... 7 Emission Calculations... 8 Non-attainment Applicability... 8 Ambient Monitoring... 9 Air Toxics BACT Analysis Miscellaneous Summary of s Received in Support... 13

3 Response to s Document Page 2 of 13 I. PUBLIC PARTICIPATION PROCESS Permit to Install application No , for DTE Electric Company - Belle River Combined Cycle (DTE), is for the installation of a new natural gas-fired combined cycle power plant for location at 4505 King Road, China Township, St. Clair County, Michigan. The public participation process involved providing information for public review including a Technical Fact Sheet, a Proposed Project Summary, and proposed permit terms and conditions. It also included a public comment period, an informational meeting, a public hearing, and the receipt of written and verbal public comments on the analysis of the application and proposed permit. On May 16, 2018, copies of the Notice of Air Pollution Period and Public Hearing, the Proposed Project Summary, the Technical Fact Sheet, and the proposed permit terms and conditions were placed on the Michigan Department of Environmental Quality (MDEQ), Air Quality Division (AQD) Home Page ( Also, on that date, the AQD mailed 104 letters to persons who had previously expressed interest in air issues in St. Clair County and had provided a complete mailing address. In addition, a notice announcing the Public Period, Public Informational Meeting, and Public Hearing was placed in The Voice, the local newspaper which covers St. Clair County including China and East China Townships. The notice provided pertinent information regarding the proposed action; the locations of available information; a telephone number to request additional information; the date, time, and location of the Public Informational Meeting and Public Hearing; the closing date of the Public Period; and the address where written comments were being received. The Public Informational Meeting and Public Hearing were held on June 18, 2018, at the East China School District Administration Office, 1585 Meisner Road, East China, Michigan. This location was selected due to its proximity to the facility and the size of the room. Approximately 23 people attended the Public Informational Meeting and Public Hearing. A panel of representatives from the AQD made a short presentation and were available to answer questions regarding the proposed project. The Public Informational Meeting began at 6:00 p.m. and concluded at approximately 7:00 p.m. The hearing began at 7:00 p.m. with Tracy Kecskemeti as the Hearings Officer, and Mary Ann Dolehanty as the Decision Maker. During the hearing, the AQD staff were available outside the room to answer any questions. The Public Hearing concluded at 7:30 pm. Approximately 422 written comments were received during the Public Period and the hearing. The remainder of this document is a listing of the significant comments received during the public comment period and hearing regarding the proposed permit and the AQD s response. The first section discusses the comments received that resulted in changes to the final permit terms and conditions and the basis for each change. The next section discusses the AQD s response to all other significant comments. The last section outlines the comments received in support of the proposed plant.

4 Response to s Document Page 3 of 13 II. SUMMARY OF COMMENTS RESULTING IN CHANGES TO THE PERMIT During the public comment period, the AQD found that the draft permit conditions contained several typographical and formatting errors. The AQD has corrected these errors. The following are specific comments made which resulted in changes to the special conditions of the permit. Page 10 of the fact sheet states the emergency engine will be limited to 4 hours of operation per day, except during emergency conditions. However, the draft permit does not limit the emergency engine's daily operations. We request you either add the daily operating hour limit to the permit or explain why this operational limit is not necessary. The commenter is correct, a daily hours of operation limit for EUEMENGINE was not included in the proposed permit. A new SC III.1 has been added within EUEMENGINE limiting the emergency engine to a maximum operation of 4 hours per calendar day, except during emergency conditions. FGCTGHRSG, SC I.8 through I.13 establish particulate matter (PM), particulate matter equal to or less than 10 microns in diameter (PM10), and particulate matter equal to or less than 2.5 microns in diameter (PM2.5) hourly Best Available Control Technology (BACT) limits. For PM10 and PM2.5, it appears the hourly limits apply at all times. However, for PM, the limit does not apply during startup and shutdown. We request you clarify whether the PM, PM10, and PM2.5 BACT emission limits should apply at all times, or at all times excluding startup and shutdown and revise the permit as necessary. Unlike other pollutants, such as volatile organic compounds (VOCs), the emissions of PM, PM10 and PM2.5 do not increase during startup or shut down operation, they remain constant. Therefore, the PM limits, like the PM10 and PM2.5 limits, are applicable at all times. The AQD has removed the language except during periods of startup and shutdown from SC I.8 and I.9 in the final permit. FGCOOLINGTWR, SC II.2 and II.3 establish BACT limits for PM and PM10, but not PM2.5. We request you verify whether the cooling tower is a PM2.5 emission source. If the cooling tower is a PM2.5 emission source, then we request you establish a cooling tower PM2.5 BACT limit. In addition to a source of PM and PM10, the cooling tower is a source of PM2.5 emissions. A limit for PM2.5 should have been included in the proposed permit. A review of the RACT/BACT/LAER Clearinghouse indicates BACT for PM2.5, like that for PM and PM10, is the use of high efficiency drift eliminators. The drift eliminators range from % to % control. A % drift elimination efficiency is consistent with the most restrictive control. This limit applies to PM, PM10 and PM2.5. Based upon the BACT determination, the AQD has added a PM2.5 emission limit for the cooling tower to the final permit.

5 Response to s Document Page 4 of 13 Several comments were received questioning the allowed sulfur dioxide (SO 2) emissions included in the proposed permit and the basis for the calculations. Specifically, that emission estimates are flawed because the sulfur content of the natural gas seems low when compared to other recently permitted facilities and appears based upon 12-year old test data. Concerns were also expressed that the proposed permit does not properly establish a Synthetic Minor limit for SO 2, and therefore the MDEQ cannot practically enforce the potential to emit of SO 2 emissions by limiting sulfur content in the gas. When the original permit to install application was submitted in January 2018, the projected SO 2 emissions from the proposed project were greater than the significance level of 40 tons per year (tpy). The original projection was based upon a maximum sulfur content of 0.50 grains of sulfur per 100 standard cubic feet of natural gas. The application, however, failed to address major source nonattainment new source review for SO 2. DTE was informed that the application needed to address major source nonattainment new source review for SO 2 or to reduce the projected SO 2 emissions below 40 tpy. On February 19, 2018, DTE requested to lower their projected SO 2 emissions to less than 40 tpy. DTE s updated SO 2 emissions estimate for the proposed facility is tpy, below the significance level of 40 tpy. The updated projection was based upon a maximum allowable sulfur content of 0.34 grains of sulfur per 100 standard cubic feet of natural gas. The 0.34 grains value was included as a limit in the proposed permit. DTE provided documentation that supports the lower value. In response to the comments received, DTE provided sampling results for 40 separate tests taken from January 19, 2017, through December 12, 2017, showing the sulfur content of natural gas provided to them. The average sulfur content of the 40 samples taken is grains of sulfur per 100 standard cubic feet of natural gas, which is 37% of the allowable sulfur in fuel content. The highest single measured concentration is 0.23 grains of sulfur per 100 scf which was 68% of the allowable sulfur in the fuel limitation. To assure on-going compliance with the sulfur content limit, a special condition was included in the final permit requiring DTE to monitor the sulfur content of the natural gas they burn at least once per month. The monitoring shall be done using acceptable ASTM fuel sampling test methods or another method acceptable to the AQD. In addition to monitoring the fuel sulfur concentration, DTE will also be required to maintain records and emission calculations of SO 2, based on the most recent gas sampling results. Also added to FGPROJECT were conditions limiting the total amount of natural gas and the total amount of diesel fuel that may be burned at the facility. In addition to those requirements, the final permit contains a requirement to track the actual amount of natural gas and diesel fuel burned at the facility. The final permit also contains a limit on the sulfur content of the diesel fuel burned at the facility; the number of hours the emergency engines may operate; and the actual hours of operation of the emergency engines. Based upon all of this, the facility is also to calculate the total actual SO 2 emissions from the facility on a monthly and 12-month rolling time-period basis. Together, these requirements are federally enforceable and will ensure the facility s status as synthetic minor for SO 2.

6 Response to s Document Page 5 of 13 The AQD added some additional special conditions and footnotes to the final permit which were inadvertently not included in the proposed permit. In the final permit, the AQD added the following additional special conditions and footnotes: SC VI.8 and SC VI.9 within EUFPENGINE Two additional footnotes intended to clarify when the emission limits apply were added to the Emission Limits Table for FGCTGHRSG. One addresses the use of the duct burners and the other one addresses startup and shutdown activities. SC VI.1 and SC VI.6 were added within FGCOOLINGTWR to include a schedule for calculation of emissions and required calculation of PM, PM10, and PM2.5 emission rates, respectively. Adding SC VI.1 resulted in the original conditions in this section being renumbered. SC V.1 requiring testing of PM emissions from the fuel heaters was added within FGFUELHTR. III. SUMMARY OF OTHER SIGNIFICANT COMMENTS A. Alternative Technologies Several comments were received indicating that DTE did not evaluate the use of other technologies including solar, wind power, energy efficiency, and energy storage for this facility. Specifically, these technologies would provide energy at less cost to the rate payer and would create more jobs. The AQD evaluates if a project proposed by an applicant meets all applicable state and federal air quality rules and regulations. This review does not include a review of alternative technologies. The application submitted by DTE showed the proposed project meets all applicable rules and regulations. As a public utility, DTE is regulated by the Michigan Public Service Commission (MPSC). Part of the MPSC s regulatory authority is to develop regulations which provide specific targets on the use of renewable fuels such as wind, solar, hydroelectric, and demand side management. It is also the responsibility of the MPSC to assure that any means to generate electricity for the general public are reasonable and prudent from a cost and reliability standpoint. In addition, it is the responsibility of the MPSC to grant to a public utility a certificate of necessity prior to them beginning construction of a new power plant. A review of alternative technologies (wind and solar) was performed by DTE as a part of the certificate of necessity process and was approved by the MPSC.

7 Response to s Document Page 6 of 13 B. Dispersion Modeling FGCTGHRSG, SC III.3 limits each CTG/HRSG to 500 hours of startup and shutdown (SU/SD) per 12- month rolling period. For the annual nitrogen dioxide (NO 2) National Ambient Air Quality Standars (NAAQS) analysis, the SU/SD scenario shows the impacts from the project do not exceed the annual NO 2 significant impact level (SIL). According to Appendix D of the application, the modeled emission rate for this scenario assumes 10 cold starts, 50 warm starts, 100 hot starts, and 160 shutdowns, totaling hours. Since the annual NO 2 modeling assumes a specific number of each type of startup and shutdown totaling less than 500 hours per year, it is not clear whether the analysis fully considers the impact of the SU/SD scenario limited to 500 hours of any type of startup or shutdown per year. We request you either provide justification showing the annual NO 2 impact at 500 SU/SD hours remains below the annual NO 2 SIL, remodel the annual NO 2 SIL analysis to show that 500 hours of SU/SD will not result in a concentration exceeding the SIL, or revise the SU/SD limit to reflect the modeled assumptions. The commenter spoke about NO 2. However, both DTE and the AQD conservatively performed the SIL analysis based upon nitrogen oxide (NO x). NO x refers specifically to nitrogen oxide and NO 2, with the larger portion being NO 2. The commenter is correct that the NO x SIL modeling was based upon startup and shutdown events from each of the two CTG/HRSG units occurring hours per year instead of 500 hours per year, as was included in the proposed permit. The original total NO x modeling rate from the two CTG/HRSG units was pounds per hour, combined. The AQD reran the NO x SIL modeling based upon startup and shutdown events from each of the two CTG/HRSG units occurring 500 hours per year. The updated total modeling rate from the two CTG/HRSG units was pounds per hour combined. The results of the updated NO x SIL modeling are shown in the following table: Significant Impact Levels (SIL) Pollutant Averaging Period SIL (ug/m 3 ) Total Maximum Impact Below SIL? (ug/m 3 ) NO x Annual Yes As the table shows, the annual NO x SIL is met while allowing total startup and shutdown events from each of the two CTG/HRSG of 500 hours per year. For the 24-hour PM2.5 Prevention of Significant Deterioration (PSD) Increment analysis, it appears the modeled emission rate for the auxiliary boiler is g/s, which is approximately 0.12 lb PM2.5/hr. EUAUXBOILER, SC I.10 limits PM2.5 emissions to 0.7 lb/hr. Since the modeled emission rate is lower than the allowable emission rate, it is not clear whether the 24-hour PM2.5 PSD Increment analysis fully considers the amount of PM2.5 PSD Increment consumed by the project. We request that you either provide justification explaining why the PM2.5 PSD Increment analysis is sufficient with a modeled auxiliary boiler emission rate that is below its allowable emission limit, remodel the 24-hour PM2.5 increment analysis at the auxiliary boiler's allowable emission rate, or revise the auxiliary boiler's PM2.5 emissions limit to match the modeled emission rate.

8 Response to s Document Page 7 of 13 The AQD reran both the PM2.5 and PM10 modeling using an emission rate of g/s (0.7 lb/hr) from the auxiliary boiler. The results of the updated modeling are shown in the following tables: Significant Impact Levels (SIL) Pollutant Averaging Period SIL PM10 PM2.5 (ug/m 3 ) Total Maximum Impact Below SIL? (ug/m 3 ) 24-Hour Yes Annual Yes 24-Hour No Annual Yes PSD Increment Modeling Impacts Pollutant Averaging Time PSD Increment (µg/m 3 ) Predicted Impact (µg/m 3 )* Percent of Increment (%) PM hr % *Includes other nearby sources. NAAQS Modeling Impacts Pollutant Averaging Time NAAQS (µg/m 3 ) Predicted Impact (µg/m 3 )* Percent of NAAQS (%) PM hr % *Includes background data. As the tables show, all PM2.5 and PM10 standards are met at an emission rate of g/s (0.7 lb/hr) from the auxiliary boiler. C. Facility Emissions, Greenhouse Gases Several comments were received indicating that natural gas combustion is not as climate-friendly as it is commonly expressed as and that the proposed plant would release a large amount of climate warming pollution, contributing to harm that is already affecting Michigan. Specifically, it was stated that the evaluation of carbon emissions should be done on a life-cycle basis rather than a power plant only basis. Although gas produces fewer carbon emissions than coal when burned, the production, processing, storage, transmission, and distribution of gas results in large amounts of methane and sulfur hexafluoride being emitted into the atmosphere.

9 Response to s Document Page 8 of 13 Evaluation of the origin of the fuel or the carbon emissions on a life-cycle basis is not part of the permit review process which the AQD implements. The AQD, as a regulatory agency, reviews proposals by applicants and compares the proposals to the air quality rules and regulations in place. Greenhouse gas emissions from the proposed facility were evaluated based on applicable federal rules and regulations. The proposed emissions meet all current regulatory requirements. The proposed power plant will generate approximately 4,100,000 short tons per year of CO2e (carbon dioxide equivalent) emissions. The two other power plants in the immediate area of the proposed facility (Belle River and St. Clair) generate a total of approximately 10,700,000 metric tons of CO2e per year (see: DTE, via communications with the MPSC, has indicated that both the Belle River and St. Clair power plants are scheduled for retirement. When the existing units are retired, there will be a reduction in CO2e emissions in the local area. DTE and other Michigan utilities are moving away from the use of coal and will be relying on renewable energy to a greater extent. Utilities are making this switch partially in response to Michigan s Renewable Portfolio Standard. D. Emission Calculations The proposed permit allows an annual limit of 88 tons of VOCs per year, which includes startup and shutdown emissions, but does not specify a level of these pollutants that will be permitted per hour during startup/shutdown. The proposed permit allows each CTG/HRSG 500 hours of startup/shutdown per year. The commenter is correct, the short-term VOC emission limits included in the permit for each of the two CTG/HRSG units do not apply during startup and shutdown events. Startup and shutdown events are relatively short in duration, usually less than one hour per event. In order to confirm VOC emissions via stack testing, three one-hour tests must be performed. As it is not possible to stack test to confirm VOC emissions during a startup or shutdown event, it is not appropriate that the VOC limits apply during these events. E. Non-attainment Applicability Several comments were received stating the AQD should evaluate the application under the nonattainment new source review (NNSR) regulations for ozone, which take effect on August 3, 2018, as well as the NNSR regulations for SO 2 which are currently in effect. Doing so would require lowest achievable emission rates (LAER) and offsets for VOCs, NO x, and SO 2. The AQD reviews permit applications in the context of the regulations in effect at the time the review is being performed. Major source NNSR for ozone (VOCs and NOx) does not become effective in Michigan until August 3, As such, until that date, the application is subject to the PSD regulations for both VOCs and NOx. The AQD completed the review under the PSD regulations and has determined they are being met and the permit is approvable. Also, DTE s application is for a minor modification of SO 2 emissions (less than 40 tpy), therefore it is not subject to major source NNSR.

10 Response to s Document Page 9 of 13 Of note, it is often assumed that LAER limits are more restrictive than BACT limits, however that is not always the case. A review of the United States Environmental Protection Agency s (USEPA) RACT/BACT/LAER Clearinghouse shows that DTE s proposed NO x emission limit on the CTG/HRSG units of 2.0 parts per million is equivalent to what has been determined to be LAER at several other similar facilities around the country. F. Ambient Monitoring Several comments were received questioning the ambient air quality monitoring data used in the review of the application. Specifically, that there are flaws in background air quality monitoring and hazardous air pollutant (HAP) monitoring data since the monitoring sites are not close. Also, the USEPA does not suggest using regional sites where there are emissions from multiple sources. Last, instead of receiving a pre-construction monitoring waiver, DTE should be required to perform actual pre-construction monitoring on the sight of the proposed plant. The AQD conducts air monitoring throughout the state using a network designed to give wide spatial coverage for a variety of parameters. The AQD is, however, unable to have monitoring stations in every city. The AQD works closely with the USEPA and the monitoring regulations to design the network to provide broad coverage to evaluate air pollution in large population areas, near certain types of industrial sources, and near major highways. The purpose of the air monitors is to determine if an area is meeting the NAAQS over a long period of time, usually averaged over a 3-year period, not to determine if a specific facility is in compliance with permit limits. The data collected can also be used as background data when performing dispersion modeling for a proposed source. For this application, DTE proposed using monitoring data from Port Huron for PM2.5 and Detroit (East 7-Mile) for NO 2. The AQD staff reviewed and determined the available data from both Port Huron and East 7-Mile is indeed representative of the air quality around the site of the proposed new DTE plant in China Township, St. Clair County. As such, as authorized by USEPA regulations, the AQD granted DTE a waiver from the need to perform pre-construction ambient monitoring for this application. Monitoring information regarding two DTE SO 2 monitors in St. Clair County has not been shared with the public since it was installed in late Starting in 2017, the data from the two DTE SO2 monitors in St. Clair County has been uploaded quarterly to the USEPA Air Quality System Database. It can be accessed from the USEPA s website at Questions about the data can be answered by contacting the MDEQ, AQD, Air Monitoring Unit at

11 Response to s Document Page 10 of 13 G. Air Toxics While the applicant predicted that its toxic emissions would not, by themselves, cause exceedances of the initial threshold screening level or the initial risk screening level, it did not account for background concentrations of those pollutants. Given the two existing coal-fired power plants and other industry in the area, these background emissions are likely to be high. The MDEQ Air Pollution Control Rules require predicted maximum ambient impacts of all toxic air contaminants (TACs) not to exceed their respective allowed screening levels. The commenter is correct that this requirement does not include background concentrations from other sources. The commenter is also concerned that background air toxics levels may be high in this area. Although accounting for background is not within the AQD s authority, there is some available information the AQD can share. Background concentrations can be estimated using the National Air Toxics Assessment, which models emission inventory data from regulated point sources, including the two nearby existing coal-fired power plants. The most recent assessment is based on 2011 data. This study estimated that the additional lifetime cancer risk from the combined point source impacts on the census tracts in the area was two in one million. This is relatively low in terms of a health concern and it is average as compared to other areas in the state. For respiratory risk, the combined impact of point sources on the census tracts surrounding the facility did not reach a level of a health concern in this study. H. BACT Analysis Several comments were received concerning the greenhouse gas (GHG) BACT analysis. Specifically, the proposed emission limits are not as stringent as those considered BACT at other combined cycle facilities and the analysis failed to evaluate a solar component in the steam generation cycle. Recent permits issued by the AQD and a review of the USEPA s RACT/BACT/LAER Clearinghouse shows the GHG BACT emission limits proposed by DTE are consistent with those found to be BACT for other similar sources. Without more specificity as to what the commenter believes BACT to be, further review was not justified. The use of solar power to assist in the generation of steam to the turbines (a hybrid solar thermal design) would constitute a redefinition of the source and would fundamentally alter the design and operation of the proposed power generation facility. According to previous court rulings, changes to the fundamental design and operation of a proposed project are not required as part of a BACT analysis. Also, any fluctuation in the plant s ability to produce steam due to the lack of necessary sunlight could greatly affect the plant s ability to operate as a baseload facility. Additionally, the MPSC, in its approval of DTE s certificate of necessity, evaluated the facility on the basis of the design which includes the fuels proposed by DTE. Through this review, the MPSC determined the proposed plant to be reasonable and prudent for the reliable production of electricity.

12 Response to s Document Page 11 of 13 I. Miscellaneous Several comments were received concerning the shutdown of DTE s existing Belle River and St. Clair power plants. Specifically, why does the draft permit not set a specific date by which DTE must shut down these plants. Also, it appears the MDEQ attempted to mislead the public as to the actual date of the shutdowns. It is feared the existing plants will operate for several more years, continuing to reduce the air quality in the area. In addition, it appears the MDEQ stated the existing plants cannot be retired until the new proposed gas plant is in operation. The shutdown of the existing Belle River and St. Clair power plants was not considered in the review of the proposed new plant. In other words, the permit was evaluated from the perspective that the two existing power plants would continue to operate. Under this scenario, the proposed project meets all federal and state air quality regulatory requirements and is approvable. As the shutdown of the existing plants was not a component of the review, the AQD has no legal authority to require mandatory shutdown dates for the existing plants. The AQD is working with DTE to address the sulfur dioxide non-attainment area in a portion of St. Clair County as part of the State Implementation Plan (SIP). It is anticipated that as a part of the updated SIP, DTE may be required to shutdown one or both of their existing coal-fired plants. It is not known, however, at this point which plant(s) will be required to shutdown and by when the shutdown(s) will be required. The draft updated SIP will undergo public comment prior to its completion, giving citizens and environmental groups an opportunity to provide input as to the exact shutdown dates. The AQD did not properly address Environmental Justice in the review of this application. Environmental justice means the fair, non-discriminatory treatment and meaningful involvement of Michigan residents regarding the development, implementation, and enforcement of environmental laws, regulations, and policies by the state. The two pillars of environmental justice are providing for meaningful public involvement in government decision-making and the fair treatment of all people. For the proposed permit for the DTE project, the AQD provided for meaningful public involvement in several ways. The AQD published the public notice in a local newspaper; provided notifications online via , tweets, and the MDEQ calendar; letters were sent to 104 people who had previously expressed interest about the proposed project; provided a short presentation about the project before the hearing; held a public information session prior to the hearing, had several staff available for discussion outside of the hearing room; and held the hearing in the local community (East China) in an auditorium with ample space. All individuals who attended the public hearing were provided an opportunity to speak. In addition, the AQD staff encouraged citizens to provide written comments as an alternative to providing verbal comments during the hearing. This outreach, education, and comment process for the permit application was consistent with the environmental justice principle of providing opportunities for enhanced public participation. As with any public hearing, a mailing list is developed of interested citizens. Because of the interest shown for this project, we now have a more robust list of interested parties for this locale for planning and outreach purposes.

13 Response to s Document Page 12 of 13 The environmental justice principle of fair treatment means that no group of people, including racial, ethnic, or low-income populations should bear a disproportionately greater burden resulting from environmental laws, regulations, policies, and decision-making. The MDEQ strives to protect the health and welfare of all citizens of the State of Michigan. In addition, the state and federal air quality standards that have been established are designed to be protective for all populations, including the most sensitive populations. Therefore, the AQD has determined the permit, as approved, will meet all applicable air quality standards and health protective requirements and is not expected to have a negative impact on the community. The proposed permit does not require prior notification to the community when there will be a planned startup or shutdown event. Such notifications should be required. Planned startups or shutdowns occur at all types of facilities, not just power plants. They occur for several different reasons including routinely scheduled maintenance and repairs, updates to equipment, and decreasing demand for the product produced (including electricity). As with all base-load plants, a minimum number of such events is expected. During startups and shutdowns, the emissions may be higher than those during normal operation, however, the AQD evaluated all operating scenarios, including start-up and shutdown. The review found that at all times, the emissions from the proposed plant will comply with all state and federal applicable air quality rules and regulations, including the NAAQS, the PSD Increments, and the State of Michigan air toxics rules. As such, a requirement for DTE to notify the community prior to a planned startup or shutdown is not necessary. Michigan Air Pollution Control Rule R (Rule 912) requires the owner or operator of a facility to notify the AQD of an abnormal condition, start-up, shutdown, or a malfunction that results in emissions of a HAP which continue for more than 1 hour or that results in emissions of any air contaminant continuing for more than 2 hours in excess of a standard or limitation. The public may have access to such notifications by contacting the MDEQ, AQD, Warren District Office at The certificate of necessity given to DTE by the Michigan Public Service Commission is in the appeal process and is being debated. The concerns of the certificate s validity are currently unresolved and action on the proposed permit should not be taken until it is known that the certificate will remain in place. The lack of a certificate of necessity does not prohibit the MDEQ, AQD from evaluating an air use permit application and taking action.

14 Response to s Document Page 13 of 13 IV. SUMMARY OF COMMENTS RECEIVED IN SUPPORT Several comments were received in support of the proposed plant. Many indicating they felt the air in the local area would improve in the long term, after the new gas plant is up and running and the existing coal plants have been shut down. Prepared by: John Vial, AQD