1 **New York State Department of Environmental Conservation Best Available Retrofit Technology Determination**  Facility Oswego Harbor Power Location Oswego, NY

Oswego County Permit ID 7
- 3512
- 00030 Source Category Fossil
- fuel fired steam electric plant of

more than 250 mmBtu/hr heat input **I. Introduction** The above referenced facility contains at least one emission source that falls under the requirements of the federal Best Available Retrofit Technology ( BART ) rule under 40 CFR Part 51 and Appendix Y, and the New York State BART regulation as codified under 6 NYCRR Part 249. These requirements affect an emission source which fulfills the following criteria: 1. Falls within one of 26 specific source categories, 2. Was not in operation prior to August 7, 196 2 and was in existence on August 7, 1977, or underwent reconstruction between August 7, 1962 and August 7, 1977, and 3. Has a potential to emit (collectively , with other emission sources at the facility which fulfill items 1 and 2) of 250 tons per year or more of any visibility
- impairing pollutant. In accordance with BART requirements, each BART
- eligible facility must perform a BART anal ys is of controls for sulfur dioxide, nitrogen oxides and particulate matter. This anal ys is takes into account such factors as the cost of controls, energy and non
- air quality environmental impacts of compliance, any existing pollution control technology in use at the source, the remaining useful life of the source, and the degree of improvement in visibility which may reasonab ly

be anticipated to result from the use of such technology
. This document reflects the Department’s determination of what level of controls constitutes BART for this facility ’s BART
- eligible emission source ( s )
. Each anal ys is and determination was submitted to the Federal Land Managers (FLMs) for their review in accordance with Regional Haze State Implementation Plan (SIP) requirements. Comments received from the FLMs on each determination will be included with its submission. The Department is now working to expeditiously modify this facility’s Title V permit to include the enforceable BART limits. Specific parameters and limits that are used as the technical bases of BART determinations, such as sulfur limits, the installation of controls, and operational limitations, will be incorporated into each facility's permit in enforceable conditions. These permit modifications will be submitted to the U.S. Environmental Protection Agency (EPA) as SIP revisions once complete.2

**II. BART**  **Analysis Summary** NRG submitted a BART anal ys is for the Oswego Harbor Power facility dated August 4, 2010, with an associated engineering evaluation for NO x dated July 26, 2010
. The following emission sources had previousl y been identified as BART
- eligible and are therefore included in the anal ys is: **Boiler No. 5**

– Emission Unit U
- 00005; Emission Source S0005  This unit is a Foster Wheeler wall
- fired boiler with a maximum heat input of 8,033 mmBtu/hr. This unit is capabl e of burning natural gas or 1.5 percent sulfur fuel oi l
. Operation commenced in 1975. **Boiler No. 6**

– Emission Unit U
- 00006; Emission Source S0006  This unit is a Foster Wheeler wall
- fired boiler with a maximum heat input of 8,088 mmBtu/hr. This unit is capable of burning natural gas or 0.75 percent sulfur f uel oil. Operation commenced in 1980. Each of these units is equipped with low NO x burners, including LN
- REACH, overfire air (OFA) and flue gas recirculation (FGR) control for NO x emissions. Each unit has an electrostatic precipitator (ESP) for PM control. Both are considered to essentially be “peaking” units , with actual capacity being much lower than rated capacity . Each unit has had a capacity

factor of 3.2 percent or less during the baseline period ( 2007

– 2009) , and n either has had a capacity factor above 10 percent since 2001. These operational characteristics were taken into account in this BART analy sis. A summary

of the analy sis’ findings for each pollutant are as follows: **Boiler No. 5**

 SO 2 O swego Unit 5 currentl y burns oil with a fuel sulfur limit of 1.5 percent b y weight. An economic analy sis indicated that switching to a lower fuel is economicall y feasible. In order to meet the presumptive limit for oil
- fired boilers set by EPA in its BART rule, NRG proposes to revise its permit limit to burn oil with a sulfur content less than 1.0 percent b y weight. Additionally , in anticipation of the Department’s plans to revis e its fuel sulfur requirements (and citing fuel handling advantages of a sin gl e oil on
- site) , NRG is committing to purchasing no oil in the future with a sulfur content greater than 0.5 percent for Units 5 and 6.

 NO x During the baseline period of 2007 to 2009, the annual capacity factor for Unit 5 ranged from 0.52 percent (2009) to 2.68 percent (2007). The highest 12
- month rolling average3

capacity factor during this period for either unit was 3.2 percent (Unit 5) ; thi s value was used as the basis in calculating the baseline and projected annual emissions for both units. The b aseline for NO x emissions from Unit 5 was found to be 243 tons per year (tp y). The average controlled NO x emission rate was 0.22 lb/mmBtu over this period. The f ollowing table presents a list of the potential NO x control technology options for Units 5 and 6. **Potential NOx**  **Control Technologies**

**Combustion Controls** Low NOx Burners (LNB), Overfire Air (OF A), and Flue Gas Recirculation (FGR) (optimize existing NOx combustion controls) Low NOx Reduced Emissions and Advanced Combustion Hardware (LN
- REACH) and modified OFA controls Neutral Network Combustion Control Systems Gas Reburn Systems and Advanced Gas Reburn Fuel Lean Gas Reburn (FLGR) and Amine
- Enhanced FLGR **Post -**  **Combustion Controls** Selecti v e Non - Catalytic Reduction (SNCR) Selective Catalytic Reduction (SCR) **Innovative Control Technologies** Rotating Overfire Air (ROFA) ROFA plus SNCR (Rotamix) NOxStar Control System Powerspan ECO Technology NRG’s BART plan describes the technical feasibility of each of these control options for Unit 5. The technicall y feasible control options are listed in the table below, in order of descending control effectiveness
. This table outlines the emissions that would remain after the application of the control technology , and the average cost
- effectiveness resulting from that level of emission reductions. ( As previously stated, the cost figures and annual emission estimates for each control option were calculated according to a 3.2 percent capacity

factor based on historical annual hours of operation.)4 **Control Technology Controlled**  **Annual Emissions (tpy)**  **Annual Emission**

**Reductions (tpy) Average Cost** 

**Effectiveness ($/ton)**  SCR 33.0 209.1 $73,113 LN - REACH (steam atomizer) + modified OFA and FLGR 132.1 110.0 $37,421 LN - REACH (steam atomizer) + modified OFA + SNCR 143.1 99.0 $22,194 LN - REACH (pressure atomizer) + modified OFA and FLGR 143.1 99.0 $36,401 LN - REACH (pressure atomizer) + modified OFA + SNCR 154.1 88.0 $19,141 LN - REACH (steam atomizer) + modified OFA 187.1 55.0 $16,873 LN - REACH (pressure atomizer) + modified OFA 198.1 44.0 $8,748 Optimize LNB/OFA/FGR with Neural Network Control System 231.1 11.0 $42,809 Baseline LNB/OFA/FGR 242.1 -- -- NRG notes that these cost
- effectiveness values exceed the $5,500 per ton figure established by

the Department for BART. NRG states that, assuming actual capacity remain s at low levels, no additional controls are economically feasible for BART. NRG reques ts that the existing low NOx burners, LN
- REACH, OFA, and FGR be accepted as BART for Unit 5 . NRG proposes to accept a NO x emission limit based on the NO x emissions level that would prevent the cheapest control option from being cost effective (i.e., becom e lower than the $5,500 per ton threshold). For Unit 5, the cheapest control option was to optimize combustion with burner changes and modify the OFA configuration ($8,748 per ton) . NRG back
- calculated the threshold emission level that would prevent this option from being cost
- effective: 405 tons, based on the 3.2 percent capacity factor used in the anal ys is. NRG proposes to modify this facility ’s permit to include a combined NO x emission limit for Units 5 and 6 of 1,201 tons (405 tons for Unit 5 combined with the 796 tons determined to be the threshold for Unit 6), or by taking the average and accepting an annual emission limit of 600 tons each for Units 5 and 6
.
 PM Unit 5 presently

operates with an ESP for particulate control. The most recent PM stack tests measured a total PM rate of 0.0304 lb/mmBtu and a filterable PM rate of 0.0217 lb/mmBtu. Because of the current level of control, additional controls proved to be economicall y infeasible. A cost an al ys is for a fabric filter unit indicated costs of5

approximately

$40,600 per ton of PM at actual emission rates. ESP conditioning was also prohibitively

expensive, at around $37,000 per ton. NRG back
- calculated the PM emission levels that would be required to make these controls cost
- effective, which proved to be much higher than the levels seen under actual operation. NRG also notes a number of ESP improvements that have been undertaken recentl y. It is recommended that the current operation of the ES P constitutes BART for PM. **Boiler No. 6**

 SO 2 Unit 6 currentl y has a permit limit for 0.75 percent sulfur oil, which is less than the presumptive limit established in the EPA BART rule of 1.0 percent or less for oil
- fired utility boilers. NRG therefore requests that the fuel currently being burned be accepted as BART. In anticipation of the Department’s plans to revise its fuel sulfur requirements (and citing fuel handling advantages of a single oil on
- site) , NRG is also committing to purchasing no oil in the future with a sulfur content greater than 0.5 percent for Units 5 and 6.

 NO x Baseline emissions for Unit 6, based on actual emissions during the baseline years of 2007 to 2009, were found to be 107 tpy . The average controlled NO x emission rate was 0.19 lb/mmBtu over this period. Potential NO x control options are the same as those provided under the Unit 5 section. NRG’s BART plan describes the technical feasibility of each of these control options for Unit 6. The technicall y feas ible control options are listed in the table below, in order of descending control effectiveness. This table outlines the emissions that would remain after the application of the control technology , and the average cost
- effectiveness resulting from that l evel of emission reductions. (Again, the cost figures and annual emission estimates for each control option were calculated according to a 3.2 percent capacity factor based on historical annual hours of operation.)6 **Control Technology Controlled**  **Annual E**  **missions (tpy) Annual Emission** 

**Reductions (tpy) Average Cost** 

**Effectiveness ($/ton)**  SCR 33.2 176.9 $86,422 LN - REACH (steam atomizer) + modified OFA and FLGR 132.7 77.4 $53,182 LN - REACH (steam atomizer) + modified OFA + SNCR 143.8 66.3 $33,140 LN - REACH (pressure atomizer) + modified OFA and FLGR 143.8 66.3 $54,354 LN - REACH (pressure atomizer) + modified OFA + SNCR 154.8 55.3 $30,459 LN - REACH (steam atomizer) + modified OFA 177.0 33.1 $27,205 LN - REACH (pressure atomizer) + modified OFA 188.0 22.1 $17,416 Optimize LNB/OFA/FGR with Neural Network Control System 199.1 11.0 $42,809 Baseline LNB/OFA/FGR 210.1 -- -- NRG notes that these cost
- effectiveness values exceed the $5,500 per ton threshold established by

the Department for BART. NRG states that, assuming actual capacity remain s at low levels, no additional controls are economically feasible for BART. NRG requests that the existing low NO x burners, LN
- REACH, OFA, and FGR be accepted as BART for Unit 6. NRG proposes to accept a NO x emission limit based on the emissions level that would prevent the cheapest control option from being cost
effective (i.e., become lower than the $5,500/ton thre shold). For Unit 6, the cheapest control option was to optimize combustion with burner changes and modify the OFA configuration ($17,416/ton). NRG back
- calculated the threshold emission level that would prevent this option from being cost
- effective: 796 tons, based on the 3.2 percent capacity factor used in the anal ys is. NRG proposes to modify this facility ’s permit to include a combined NO x emission limit for Units 5 and 6 of 1,201 tons (405 tons for Unit 5 combined with the 796 tons for Unit 6), or b y taking the average and accepting an annual emission limit of 600 tons each for Units 5 and 6.

 PM Unit 6 presently

operates with an ESP for particulate control. The most recent PM stack tests measured a total PM rate of 0.0296 lb/mmBtu and a filterable PM rate of 0.0218 lb/mmBtu. Because of the current level of control, additional controls proved to be economicall y infeasible. A cost anal ys is for a fabric filter unit indicated costs of7

approximately

$57,300 per ton of PM at actual emission rates. ESP conditioning was also prohibitively

expensive, at around $48,800 per ton. NRG back
- calculated the PM emission levels that would be required to make these controls cost
- effective, which proved to be much higher than the levels seen under actual operation. NRG also notes a number of ESP improvements that have been undertaken recentl y. It is recommended that the current operation of the ESP constitutes BART for PM. **III. BART Determination**  The Department finds that the following shall constitute BART for the Oswego Harbor Power emission sources: **Boiler No. 5**

 SO 2 The Department accepts NRG’s commitment to lower the permitted No. 6 fuel sulfur limit to less than 1.0 percent by weight. This is in line with the EPA presumptive limit for sulfur in fuel of 1.0 percent or less by weight (Appendix Y, Section IV.E.4, “SO 2 limits for Utility

Boilers”). It should be noted that the Department is pursuing a regulatory revision to 6 NYCRR Part 225
- 1 t o lower the acceptable fuel sulfur limit to 0.5 percent statewide (not including the New York City and lower Hudson Valley areas, which are already subject to more stringent limits). This revision is tentatively scheduled to be effective for 2014. The Department has made facilities aware of this upcoming requirement and indicated it may supersede BART limits such as the “less than 1.0 percent ” limit recommended by NRG for Unit 5
. In its BART plan, NRG has committed to future purchases of oil with a sulfur content no higher than 0.5 percent for Unit 5.

 NO x The Department accepts NRG’s finding that no additional controls are necessary to satisfy BART for NO x for Unit 5. All available control options were ruled out due to technical or economic infeasibility
. Note: The Department is currently working with NRG to determine an appropriate NO x emission limit for Unit 5. The sources of cost assumptions in NRG’s BART plan la ck specificity, and because NRG is basing its proposed emission limits on the costs of controls, the Department is requiring greater detail on these cost sources and the facility

specific assumptions that were made. This request is not expected to alter the “no control” determination , but will provide the Department with a better idea of the8

acceptability of the proposed emission limits. A ny additional material made available to the Department will be included in the final BART submission to EPA.

 PM The Department accepts the current use of an ESP as BART for PM. NRG demonstrated that alternate controls were economically infeasible. **Boiler No. 6**

 SO 2 The Department accepts the current No. 6 fuel sulfur limit of 0.75 percent by weight as BART for SO 2 . This is in line with the EPA presumptive limit for sulfur in fuel of 1.0 percent or less b y weight (Appendix Y, Section IV.E.4, “SO 2 limits for Utility Boilers”). In its BART plan, NRG has committed to future purchases of oil with a sulfur content no higher than 0.5 percent for Unit 6
.
 NO x The Department accepts NRG’s finding that no additional controls are necessary to satisfy BART for NO x for Unit 6. All available control options were ruled out due to technical or economic infeasibility
. Note: The D epartment is currently working with NRG to determine an appropriate NO x emission limit for Unit 6. The sources of cost assumptions in NRG’s BART plan lack specificity, and because NRG is basing its proposed emission limits on the costs of controls, the De

partment is requiring greater detail on these cost sources and the facility

specific assumptions that were made. This request is not expected to alter the “no control” determination , but will provide the Department with a better idea of the acceptability of the proposed emission limits. A ny additional material made available to the Department will be included in the final BART submission to EPA.

 PM The Department accepts the current use of an ESP as BART for PM. NRG demonstrated that alternate controls were economically infeasible.