## COMMONWEALTH OF 

## MASSACHUSETTS 

## EXECUTIVE 

## OFFICE OF 

## ENERGY & 

## ENVIRONMENTAL 

## AFFAIRS 

## D**EPARTMENT OF** 

## E **NVIRONMENTAL** 

## P **ROTECTION** 

## W**ESTERN** 

## R**EGIONAL** 

## O**FFICE** 436 Dwight Street  Springfield, Massachusetts 01103  (413) 784

- 1100
DEVAL L. PATRICK Governor TIMOTHY P. MURRAY Lieutenant Governor IAN A. BOWLES Secretary LAURIE BURT Commissioner 

### Please note that some provisions of this approval are shown in **strikeout for the sole**  **purpose of showing what provisions are not incorporated i nto the Massachusetts Regional**  **Haze State Implementation Plan (SIP). The provisions shown in strikeout are a part of th e**  **approval and are state enforceable.**

**This information is available in alternate format. Call Donald M. Gomes, ADA Coordinator at 617 -** **556 -** **1057. TDD# 866 -** **539 -** **7622 or 617 -** **574 -** **6868.** DEP on the World W ide Web: http://www.mass.gov/dep

Printed on Recycled Paper

May 15 , 2009
Mr. John S. Murray RE: **Holyoke** Station Manager Western Region Mt. Tom Generating Company, LLC 310 CMR 7.29 200 Northampton Street Power Plant Emission Standards Holyoke, MA 01040 Application No. 1 - E- 01 - 072 Transmittal No. W025214 **AMENDED EMISSION CONTROL PLAN** 
Dear Mr. Murray: The Western Region of the Department of Environmental Protection, Bureau of Waste Prevention (MassDEP) , has reviewed your Amended Emission Control Plan (ECP) application dated November 6, 2008, including the December 1, 2004 ECP modification application. MassDEP originally issued the ECP on June 7, 2002. This Amended ECP application was submitted in accordance with 310 CMR 7.29(6)(a)(4) to incorporate the Turbosorp® emi ssions control system and approve the use of coal with higher ash content i n accordance with 310 CMR 7.05(3)(c) and higher sulfur content in accordance with 310 CMR 7.05(1)(b)3. This modification will require more stringent emission limits for particulate matter ( PM ) than previously required and actual stack emissions of sulfur dioxide ( SO 2) lower than the requirements of 310 CMR 7.29 . MassDEP’s Amended ECP Final Approval includes these limits as enforceable permit requirements This amended approval describes how emission limitations and compliance schedules for the control of certain designated pollutants contained in 310 CMR 7.29, “Emission Standards for Power Plants,” will be implemented for equipment and processes located at the Mt. Tom Generating Com pany, LLC. , Mt. Tom Station facility (ORISP 01606, hereinafter Mt. Tom ) on Northampton Street in Holyoke, Massachusetts. This application for the approval of the ECP bears the signature of John P. Campbell, Sr. Vice President
– Asset Operations as the com pany contact responsible for compliance with 310 CMR 7.29.Mt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 2 of 12 **AMENDED ECP SUMMARY** The amended ECP application includes Mt. Tom ’s mercury (Hg) emission control plan, proposes the utilization of a Turbosorp® control device for the reduction of Hg and SO 2 to m eet the requirements of 310 CMR 7.29, and requests approval to burn coal with a 12 percent ash content and a sulfur content of up to 3 lb/MMBtu heat release potential on a 30-day rolling average . Mt. Tom is in the process of installing a Babcock Power E nvironmental Turbosorp ® dry scrubber system that was approved by the MassDEP on December 31, 2007 ( 1 - P- 07 - 049) to control emissions of SO 2 and Hg from the boiler. The Turbosorp system is being installed downstream from the electrostatic precipitator and u pstream from the existing facility stack. Gases that exit the precipitator first enter the “Turbosorp” tower. Within the tower, the flue gas is cooled with water, then a fluidized bed of hydrated lime, PAC, B- PAC and/or sodium tetrasulfide reacts with th e flue gas. The sorbent is captured along with the particulate matter in the baghouse portion of the system. Mt. Tom is statin g that with the installation of the Turbosorp® dry scrubber system to control emissions, the station will be able to utilize dom estic sources of coal which typically have higher sulfur and higher ash content . Mt. Tom is proposing to utilize coals that contain up to 12 percent ash and 3 lb/MMBtu sulfur content and utilize controls to achieve lower stack emissions than required unde r 310 CMR 7.29. MassDEP agrees that the combustion of coals with lower stack emissions is beneficial to the environment and approves the use of coal with ash content up to 12 percent by weight and sulfur content up to 3 lb/MMBtu , provided that Mt. Tom meets the emission limits contained in Table 2 of this Approval and also revises their Title V Operating Permit renewal application to include a limit of 0.025 lb/MMBtu for PM (incl uding condensa bles, based on concurrent BACT determination on similar project at Brayton Point Station Unit 3 ) . Mt. Tom will use all reasonable efforts to meet the 0.025 lb/MMBtu PM emission limit, including, but not limited to, proper maintenance of the proposed baghouse filters in accordance with manufacturer’s recommendations. A stack test will be performed within twelve months of installation of the Turbosorp® system. If the stack tests show the proposed limit cannot be met, Mt. Tom will re-visit the emission limit with DEP.
**LEGAL AUTHORITY** MassDEP has adopted 310 CMR 7.29 - a regulation to lower emissions of sulfur dioxide (SO 2), carbon dioxide (CO 2), and nitrogen oxides (NOx) from certain power plants, and to establish a framework for reductions in emissions of carbon monoxide (CO), mercury (Hg), and fine particulate matter (PM 2.5) - pursuant to the Massachusetts General Laws, Chapter 111, Sections 142 A- M. Regulation 310 CMR 7.29 requires any person who owns, leases, operates or controls an affected facility to comply with 310 CMR 7.29 in its entirety. An affected facil ity means a facility which emitted greater than 500 tons of SO 2 and 500 tons of NOx during any of the calendar years 1997, 1998, or 1999, and which includes a unit which is a fossil fuel fired boiler or indirect heat exchanger that: (1) is regulated by 40 CFR Part 72 (the Federal Acid Rain Program); (2) serves a generator with a nameplate capacity of 100 megawatts (MW) or more; (3) was originally permitted prior to August 7, 1977; and (4) had not subsequently received a Plan Approval pursuant to 310 CMR 7.0 0: Appendix A or a Permit pursuant to the regulations for Prevention of Significant Deterioration, 40 CFR Part 52, prior to October 31, 1998.Mt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 3 of 12 The purpose of 310 CMR 7.29 is to control emissions of NOx, SO 2, Hg, CO, CO 2, and PM 2.5 (together, "pollutants") from affected electric generating facilities in Massachusetts. 310 CMR 7.29 accomplishes this by establishing maximum output- based emission rates for NOx, SO 2, and CO 2, and establishing a cap on CO 2 and Hg emissions from affected facilities. Emission limi ts for CO and PM 2.5 have not been addressed at this time. Applicable requirements and limitations contained in 310 CMR 7.29 shall not supersede, relax or eliminate any more stringent conditions or requirements (e.g. emission limitation(s), testing, record keeping, reporting, or monitoring requirements) established by regulation or contained in a facility's previously issued source specific Plan Approval(s) or Emission Control Plan(s). On December 7, 2007, Mt. Tom entered into an Administrative Consent Order (ACOPWE- 07- 7009) to install and commence operation of the Turbosorp® system in order to meet the SO2 and Hg emission rate specified under 310 CMR 7.29 (5) 2 and 3 respectively, without using Massachusetts SO 2 Early Reduction Credits. The Consent Order also requires Mt. Tom to meet an average Hg emission rate of 0.0075 lb/GWh for the period of January 1, 2008 through September 30, 2012. If Mt. Tom fails to meet this rate then an offset of the excess emission shall be provided from offsite Hg reducti ons at a 20 to 1 ratio. Pursuant to 310 CMR 7.05(3)(c) and 310 CMR 7.05(1)(b)3. , MassDEP may approve the use of a solid fuel with a higher sulfur content than those contained in Table 1 of 310 CMR 7.05(1) and an ash content higher than 9 percent provided that this would not cause any applicable air pollution control regulations or ambient air quality standards to be violated. This approval meets this standard due to the reduction in emissions. In accordance with 310 CMR 7.05(3)(c) 3. and 310 CMR 7.05(1) (b)3 , Mt. Tom must agree to the new fuel sulfur and ash content and emission limits (limits for Hg, SO 2, and PM) before using the fuel referenced in this approval . Mt. Tom must notify Mass DEP 30 days prior to burning fuel with a sulfur content greater tha n 1.21 lb/MMBtu or an ash content of greater than 9% on a rolling 12 month average. The lower emission limits noted in this Amended ECP Final Approval will become effective when Mass DEP is notified of this fuel change. On April 7, 2009 MassDEP issued for public comment an Amended ECP Draft Approval. A Public Notice on the proposed approval of the Amended ECP Draft Approval was published in the Springfield Republican on April 7, 2009 . No oral or written public comments were received during the public comment period . Based upon the above, MassDEP has determined that the referenced Amended ECP application is administratively and technically complete and that the proposed modifications are in conformance with current air pollution control engineering practices and hereby issues this **Amended ECP Final Approval** for the proposed modifications of your power plant unit, with the conditions listed below.Mt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 4 of 12 **1. EQUIPMENT DESCRIPTION** The following emission units (Table 1) are subject to and regulated by this **Ame nded**  **ECP Final**  **Approval** : **Table 1*** EU # DESCRIPTION OF

EMISSION UNIT EU DESIGN CAPACITY POLLUTION CONTROL MEASURES (PCM) 1 (MMBTU/HR) MW (NET) EU 1 Mt. Tom Unit 1

Riley Stoker Boiler 1,480 147 Turbosorp® control device Upgraded combustion controls and burner

system Selective Catalytic Reduction (SCR) SO 2 Early Reductions 2 SO 2 Allowances 3 **Table 1 Notes:** 1. Details of Mt. Tom ’s Pollution Control Measures including alternatives under consideration are described in Section E, F, and G of their original ECP application and their ECP modification application. 2. See Special Condition 2. 3. See Special Condition 3.
* Legend to Abbreviated Terms within Table 1:

EU# = Emission Unit Number MMBTU/HR = million British Thermal Units per hour MW (NET) = net electrical output in Megawatts SO 2 = Sulfur DioxideMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 5 of 12 **2. APPLICABLE REQUIREMENTS** A. EMISSION LIMITS AND RESTRICTIONS Mt. Tom shall comply with the emission limits/restrictions as contained in Table 2 below. The schedule for compliance with these emission limitations is contained in Table 6 of this **Amended ECP Final**  **Approval** . **Table 2 *** EU # RESTRICTION/

OPERATING PRACTICES POLLUTANT EMISSION LIMIT/STANDARD APPLICABLE REGULATION AND/OR APPROVAL NUMBER EU 1 NA NOx Shall not exceed 1.5 lbs/MWh calculated over any consecutive 12 month period, recalculated

monthly. 310 CMR 7.29(5)(a)1.a. Shall not exceed 3.0 lbs/MWh calculated over

any individual month. 310 CMR 7.29(5)(a)1.b. SO 2 Shall not exceed 6.0 lbs/MWh calculated over

any consecutive 12 month period, recalculated

monthly. 310 CMR 7.29(5)(a)2.a. Shall not exceed 3.0 lbs/MWh calculated over any consecutive 12 month period, recalculated

monthly. 310 CMR 7.29(5)(a)2.b.i. Shall not exceed 6.0 lbs/MWh calculated over

any individual month. 310 CMR 7.29(5)(a)2.b.ii. Shall not exceed 2.0 lbs/MWh calculated over any consecutive 12 month period, recalculated

monthly. Approval 1 - E-01 -0724 Shall not exceed 3.0 lbs/MWh calculated over

any individual month. Approval 1 - E-01 -0724Mt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 6 of 12 **Table 2 Notes:**
4 . SO 2 emissions are actual measured emissions from the facility. Mt. Tom shall not use any SO 2

early reductions or SO 2 allowances to achieve this emission rate.

* Legend to Abbreviated Terms within Table 2:

EU# = Emission Unit Number lbs/MWh = pounds per Megawatt- hour of net electrical output lbs/GWh = pounds per Gigawatt- hour of net electrical output NOx = Nitrogen Oxides SO 2 = Sulfur Dioxide Hg = Mercury CO = Carbon Monoxide CO 2 = Carbon Dioxide PM 2.5 = Fine Particulate Matter NA = not applicableMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 7 of 12 B. COMPLIANCE DEMONSTRATION The facility is subject to the monitoring/testing, record keeping, and reporting requirements as contained in Tables 3, 4 and 5 below and 310 CMR 7.29, as well as the applicable requirements contained in Table 2: **Table 3 *** EU# MONITORING/TESTING REQUIREMENTS EU 1 Actual emissions shall be monitored for the individual unit in the calculation for

demonstrating compliance. Actual emissions shall be monitored in accordance with 40 CFR Part 75 for SO 2, and NOx . Monitor actual net electrical output, expressed in megawatt- hours. Actual net electrical output shall be provided for the individual unit in the calculation for demonstrating compliance. Actual emissions shall be monitored for individual units and monitored as a facility total for all units included in the calculation demonstrating compliance.

***** Legend to Abbreviated Terms within Table 3: EU# = Emission Unit Number NOx = Nitrogen Oxides SO 2 **=** Sulfur Dioxide Hg = Mercury CO = Carbon Monoxide CO 2 **=** Carbo n Dioxide PM 2.5 = Fine Particulate Matter CEMS = Continuous Emissions Monitoring SystemMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 8 of 12
**Table 4 *** EU# RECORD KEEPING REQUIREMENTS EU 1 Maintain a record of actual emissions for each regulated pollutant for each of the preceding

12 months. Actual emissions shall be recorded for individual units and as a facility total for all units included in the calculation demonstrating compliance. Actual emissions provided under this section shall be recorded in accordance with 40 CFR Part 75 for SO 2, and NOx, i.
Maintain a record of actual net electrical output for each of the preceding 12 months, expressed in megawatt- hours. Records of actual net electrical output shall be maintained for the individual unit in the calculation demonstrating compliance. Maintain a record of the resulting output- based emission rates for each of the preceding 12 months, and each of the 12 consecutive rolling month time periods, expressed in pounds per megawatt- hour. Output based emission rates shall be provided for the individual emission unit in the calculation demonstrating compliance. Keep all measurements, data, reports and other information required by 310 CMR 7.29 on -site for a minimum of five years, or any other period consistent with the affected facility’s Operating Permit.
***** Legend to Abbreviated Terms within Table 4: EU# = Emission Unit Number NOx = Nitrogen Oxides SO 2 **=** Sulfur Dioxide Hg = Mercury CO = Carbon Monoxide CO 2 **=** Carbon Dioxide PM 2.5 = Fine Particulate Matter CEMS = Continuous Emissions Monitoring SystemMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 9 of 12
**Table 5 *** EU# REPORTING REQUIREMENTS EU 1 By January 30 of the year following the earliest applicable compliance date for the affected

facility under 310 CMR 7.29(6)(c), and January 30 of each ca lendar year thereafter, the company representative responsible for compliance shall submit a compliance report to MassDEP demonstrating the facility’s compliance status with the emission standards contained in 310 CMR 7.29(5)(a) and in an approved Emission Control Plan. The report shall demonstrate the facility’s compliance status with applicable monthly emission rates for each month of the previous calendar year, and each of the twelve previous consecutive 12 - month periods. The compliance report shall in clude all statements listed in 310 CMR 7.29(7)(b)4. 1


MassDEP may verify the facility’s compliance status by whatever means necessary, including but not limited to requiring the affected facility to submit information on actual electrical output of company generating units provided by the New England Independent System Operator (ISO), or any successor thereto. FACILITY
**Table 5 Notes** 1. If the ISO final settlement of actual electrical output is not available, the facility shall submit a compliance report based on provisional values of actual electrical output. Upon receiving certified ISO values of actual electrical output for all provisional months within the calendar year, the facility shall submit a revised compliance report within 30 days thereafter.
* Legend to Abbreviated Terms within Table 5: EU# = Emission Unit NumberMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 10 of 12 3. **COMPLIANCE SCHEDULE** The affected facility shall be in full compliance with the applicable requirements in accordance with the dates below: **TABLE 6 *** **COMPLIANCE PATH POLLUTANT**  **STANDARD DATE**  NOx SO 2 310 CMR 7.29(5)(a)1.a.

310 CMR 7.29(5)(a)2.a. October 1, 2006 NOx SO 2 310 CMR 7.29(5)(a)1.b.

310 CMR 7.29(5)(a)2.b. October 1, 2008 SO 2 Shall not exceed 2. 0 lbs/MWh

calculated over any consecutive 12 month period, recalculated

monthly. October 1, 2009
Shall not exceed 3.0 lbs/MWh calculated over any individual

month.

***** Legend to Abbreviated Terms within Table 6: NOx = Nitrogen Oxides SO 2 = Sulfur Dioxide Hg = Mercury CO 2 = Carbon DioxideMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 11 of 12 **4. SPECIAL CONDITIONS FOR ECP** 1. MassDEP may verify compliance of 310 CMR 7.29(5) by whatever means necessary, including but not limited to: inspection of a unit's operating records; requiring the facility to submit information on actual electrical output of company generating units provided to that person by the New England Independent System Operator, or any successor thereto; testing emission monitoring devices; and, requiring the facility to conduct emissions testing under the supervision of MassDE P . 2. In accordance with 310 CMR 7.29(5)(b)2., the amount of SO 2 early reductions, with supporting information, shall be provided to MassDEP prior to use for compliance with 310 CMR 7.29(5)(a)2.a. Each ton of reduction may be used, once, to offset one to n of excess emissions from the facility. Excess emissions are any emissions above a level equal to the net electrical output of the facility times the applicable emission standard in 310 CMR 7.29(5)(a)2. 3. In accordance with 310 CMR 7.29(5)(b)3., when u sing SO 2 allowances created pursuant to 40 CFR Part 72 (the Federal Acid Rain Program), three allowances shall be used to offset each ton of excess emissions above the emission standard . Such SO 2 allowances shall be in addition to those allowances used by the facility to comply with the requirements of 40 CFR Part 72, and shall be transferred to MassDEP and retired for the benefit of the environment.
**5. GENERAL CONDITIONS FOR ECP** 1. The facility shall maintain continuous compliance at all times with the terms of this Amended ECP Final Approval and the applicable emission rates in 310 CMR 7.29. 2. This Amended ECP Final Approval may be suspended, modified, or revoked by MassDEP, i f at any time the facility is violating any applicable Regulation(s) or condition(s) of this Final ECP Approval letter. 3. This Amended ECP Final Approval consists of Mt. Tom ’s application materials and this Amended ECP Final Approval letter. If conflicting information is found between these two documents, then the requirements of this Amended ECP Final Approval letter shall take precedence over the documentation in the application materials. 4. Should a condition of air pollution occur as a result of th e operation of this unit, then the facility shall immediately take appropriate steps to abate said condition even though the facility is otherwise in compliance with this Amended ECP Final Approval . 5. This Amended ECP Final Approval does not negate the responsibility of the facility to comply with this or any other applicable federal, state, or local regulations now or in the future. N or does this Amended ECP Final Approval imply compliance with any other applicable federal, state, or local regulations n ow or in the future. 6. If provisions or requirements from any other regulation or permit conflict with a provision of 310 CMR 7.29, the more stringent of the provisions will apply unless otherwise determined by MassDEP in the affected facility’s Operati ng Permit. 7 

### . Failure to comply with any of the above stated provisions will constitute a violation of the "Regulations", and can result in the revocation of the Amended ECP FinalMt. Tom Generating Company, LLC. **Amended ECP Final Approval**

Application 1

-E
-01
-072, Transmittal W025214 Page 12 of 12 Approval granted herein.

Should you have questions concerning this matter or regarding the terms or conditions of this **Amended ECP**  **Final Approval**  , please do not hesitate to contact Marc Simpson in writing at 436 Dwight Street, Springfield, MA 01103 or by telephone at 413- 755 - 2115.

Sincerely,

___________________ Marc Simpson Permit Section Chief Western Regional Office

ec: USEPA - Region 1, Air Permitting Program: Ida McDonnell DEP/BWP- NERO: Edward J. Braczyk DEP- Boston: Yi Tian