FINAL DETERMINATION To Grant a Temporary Permit/Non-Attainment New Source Review Permit For Concord Steam Corporation To Construct a 305 MMBtu/hr Biomass Boiler (Wood & Natural Gas), 2 Auxiliary Boilers (76.8 MMBtu/hr each unit, firing Natural Gas only), and 2 Emergency Generators (Rated at 6,000 kw and 1,250 kw) At Concord Steam Corporation located at 291 S. Main St. in Concord, NH Prepared by the New Hampshire Department of Environmental Services Air Resources Division February 27, 2009
TABLE OF CONTENTS I. Applicant s Name and Address:... 3 II. Physical Address of the Facility:... 3 III. Background:... 3 IV. Project Description:... 4 V. Summary of LAER Emission Limitations:... 5 VI. Air Quality Impact Analysis:... 6 VII. Conclusion:... 7
Final Determination Page 3 I. Applicant s Name and Address: II. Concord Steam Corporation P.O. Box 250 Concord, NH 03301-0250 Physical Address of the Facility: Concord Steam Corporation 291 South Main Street Concord, NH 03301 County: Merrimack UTM Coordinates: Easting: 274452 m Northing: 4784830 m III. Background: On March 17, 2008, Concord Steam Corporation (CSC) submitted an application for a Non-Attainment New Source Review (NSR) Permit in accordance with the New Hampshire Code of Administrative Rules Part Env-A 618, Additional Requirements in Non-Attainment Areas and the New Hampshire Portion of the Northeast Ozone Transport Region, and Part Env-A 607, Temporary Permits, respectively. CSC submitted supplemental information on April 9, 2008 in support of its original application submittal. In addition, CSC submitted a change in plans for Boilers 1, 2, and 3 on September 12, 2008. CSC proposes to construct a 19.5 MW biomass fired power plant with auxiliary equipment. The permit application also included information concerning the pollution control equipment and raw material receiving, storage, and transfer equipment for Boiler 1, as well as the auxiliary combustion devices that are related to this project. The CSC facility is a major stationary source under the NSR program, as emissions of nitrogen oxides (NOx), a non-attainment pollutant, will be in excess of the major source threshold of 50 tons per year 1. As a result, the proposed project is subject to the non-attainment New Source Review (NSR) and Temporary Permit permitting requirements contained in Env-A 618 and Env-A 607, respectively. On January 16, 2009, DES issued a Statement of Basis (Preliminary Determination) recommending that a Temporary Permit/NSR Permit be issued to CSC. The Preliminary Determination detailed DES technical and regulatory review and contained a Draft Temporary Permit/NSR Permit containing conditions for the proposed operation. Public notices were published in the Union Leader and Concord Monitor newspapers on January 16, 2009, respectively, notifying the public of the Preliminary Determination, NOx offsets required, the emissions resulting from the installation of the proposed facility, the determination of Lowest Achievable Emission Rate (LAER) for NOx, including the type of equipment and the prescribed LAER emission limits, and that an ambient air dispersion modeling analysis was performed, determining that the facility will not cause a significant impact on air quality and does not violate any state or federal air quality standards. Requests for a public hearing and/or written comments filed with the Director in accordance with Env-A 1 The NSR major source threshold for NOx is 50 tons per year in Merrimack, Hillsborough, Strafford, and Rockingham counties and 100 tons per year for the remaining portion of New Hampshire. 3
Final Determination Page 4 621.06 and received no later than February 16, 2009, were considered by the Director in making a final decision. No comments were received from the general public, Federal Land Manager, or USEPA Region I during the comment period. As no comments were received regarding this permit application, DES did not make any changes (to the conclusions reached in the Preliminary Determination) in this Final Determination. IV. Project Description: CSC proposes to build a wood-fired power plant on approximately 25 acres of land along and south of Langdon Street in the southern part of Concord, New Hampshire. The facility will generate electricity for sale to the grid and steam for the district heating system in the city of Concord. This facility will replace the former Concord Steam Plant located on Pleasant Street in Concord. The plant is a combined heat power (CHP) type operation with energy efficiency of approximately 39%. Some of this efficiency is due to the use of a Riley Power Boiler and its integrally efficient combustion design. The Riley Stoker is an approved combustor by the Massachusetts Division of Energy Resources (MADOER) and qualifies for Massachusetts Renewable Energy Credits (RECs). Boiler 1 has a multi-clone followed by a dry electrostatic precipitator (ESP) for removal of particulate matter. A cold selective catalytic reduction (C-SCR) system follows the ESP for NOx removal at temperatures around 450 degrees Fahrenheit. Aqueous ammonia solution at 19% ammonia, by weight, is injected into the SCR inlet, and is designed to chemically react with the NOx and convert it to nitrogen and water, with unreacted ammonia emissions, referred to as the ammonia slip stream emissions, to be less than 20 ppm by dry volume at 6% oxygen. Waste heat from the flue gas leaving the SCR is extracted using a condensing heat exchanger (CHX). The condensed water from the flue gas is reused. The Boiler 1 feedwater is preheated by the CHX. This new design allows more steam to drive the steam-driven turbine, instead of heating feed water, hence, producing more electricity. The condenser also removes certain salts and organic condensible matter, which have a high boiling point. Only virgin wood chips and non-contaminated wood products such as pallet wood chips or untreated wood product chips will be used as fuel for Boiler 1. Natural gas will be used to initially start up and warm up Boiler 1. Fuels derived from construction and demolition wood waste are specifically prohibited from being used as fuel for Boiler 1. Auxiliary equipment includes a spray cooling pond that will be used for cooling water from Boiler 1. In addition, there are two boilers, Boiler 2 and Boiler 3, which are both rated at 76.8 MMBtu/hr gross heat input rate and will be capable of burning natural gas only. These two boilers will be restricted to less than 700 hours of operation per consecutive 12-month period and will be used when Boiler 1 is out of service to provide steam to the district heating system in the City of Concord. In addition, the facility will have two diesel-fired emergency generators (EG1 and EG2) rated at 600 kw and 1,250 kw, respectively, for emergency lighting and start up of Boiler 1, in the event of a power outage at the facility. The two emergency generators will be 4
Final Determination Page 5 limited to less than 500 hours of operation per consecutive 12-month period. EG1 will be relocated from the Pleasant Street facility to the new site at 291 South Main Street. In summary, the pollutant emitting equipment which require permitting include: One Wood & Natural Gas fired boiler, rated at 305 MMBtu/hr gross heat input rate; A Spray Cooling Pond for the Wood & Natural Gas fired boiler; Two Auxiliary Boilers firing Natural Gas only, each rated at 76.8 MMBtu/hr gross heat input rate; and Two Emergency Generators, rated at 600 kw and 1,250 kw. Table 1 below summarizes the net emissions increases from the proposed project. Table 1 Net Emissions Increases Pollutant Program Projected Project Emissions tons per year (tpy) Major Source Threshold (tpy) Is Proposed Project Major? (Yes/No) NOx NSR 95.93 50 Yes NOx PSD 95.93 250 No CO PSD 246.51 250 No PM PSD 41.65 250 No SO 2 PSD 34.15 250 No VOC NSR 12.48 50 No Lead PSD 0.00022 0.6 No V. Summary of LAER Emission Limitations: In accordance with non-attainment New Source Review regulations, the proposed facility is subject to a lowest achievable emission rate (LAER) for emissions of NOx. LAER is defined as that rate of emissions which reflects (a) the most stringent emission limitation which is contained in the implementation plan of any State for such class or category of source, unless the owner or operator of the proposed source demonstrates that such limitations are not achievable; or (b) the most stringent emission limitation which is achieved in practice by such class or category of source, whichever is more stringent. On January 16, 2009, DES issued a Preliminary Determination and Draft Temporary Permit/NSR Permit for the proposed project. The Preliminary Determination explained DES review of the permit application and included a detailed discussion on the non-applicability of 5
Final Determination Page 6 the PSD program and applicability of the NSR program and the requirement to apply LAER limits for NOx. The Preliminary Determination contained proposed LAER limits for all applicable NSR pollutants and the rationale used in establishing those limits. Table 2 lists all applicable LAER limits contained in the Temporary Permit/NSR Permit. Table 2 Summary of LAER Emissions Limitations (All NOx Emissions Limitations Based on 3-hour Averaging Period Unless Otherwise Specified) Pollutant NOx limit (Basis) Wood & Natural Gas fired Boiler (Boiler 1) 0.065 lb/mmbtu (30-day rolling average) (LAER) Auxiliary Boilers 2 and 3 (Each Device) 0.049 lb/mmbtu (Natural Gas) (LAER) Emergency Generators 1 and 2 (Each Device) 1.98 lb/mmbtu (Diesel Fuel) (LAER) NOx Control Technology Selective Catalytic Reduction Low NOx Burners, Flue Gas Recirculation, and < 500 hours operation per consecutive 12 month period < 700 hours operation per consecutive 12 month period An internal comment was made concerning the 30-day averaging period for Boiler 1, i.e., if a facility could use down days as a zero in calculating the average. As a result of that comment, DES has added qualifying language to the 0.065 lb NOx/MMBtu emission limit based on a 30-day rolling average, indicating that it is to only include successive calendar operating days when the plant operated for a continuous 18 hour period during the calendar day. VI. Air Quality Impact Analysis: Section IX of the Preliminary Determination presented a detailed overview of the ambient air impact analyses that were conducted as part of the permit application review. The analyses demonstrated that the emission increases from the proposed facility will remain below all applicable state/federal ambient air quality standards, including PSD Class I and Class II increment levels, Ambient Air Limits (for applicable regulated air toxic pollutants) and National Ambient Air Quality Standards. As no comments were received regarding these analyses, no further discussion is contained in this Final Determination. 6
Final Determination Page 7 VII. Conclusion: It is the Final Determination of DES that a Temporary Permit/NSR Permit be granted to CSC. This determination is based upon the review of the application submitted by CSC and is supported by the findings outlined in the Preliminary Determination and this Final Determination. 7