### 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 Retr ofit Technology (BART) rule under 40 CFR Part 51 and Appendix Y, and the New York State BA RT regulation as codified under 6 NYCRR Part 249. These requirements affect an emission s ource which fulfills the following criteria:

1. Falls within one of 26 sp ecific source categories,

2. Was not in operation prior to August 7, 1962 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 ot her 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 performed a BART analysis of controls for sulfur dioxide, nitrogen oxides and particul ate matter. This analysis took

into account such factors as the cost of c ontrols, energy and non-air quality environmental impacts of compliance, any existing pollution co ntrol technology in use at the source, the remaining useful life of the source, and the de gree of improvement in visibility which may reasonably be anticipated to result from the use of such technology.

This document summarizes the reasoning be hind the Department’s BART determination, including the level of cont rols and emission limits that constitute BART for this facility’s eligible emission source(s). Each analysis and BART 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 this determination will be included

with its official submission to the U.S. Environmental Protection Agency (EPA).

The Department has modified this facility’s Title V permit to include the enforceable BART

limits. The modifications were noticed in New York State’s Environmental Notice Bulletin on February 15, 2012. Upon completion of this public notice period, the modified permit was submitted to EPA for review on April 4, 2012. The final modified permit was issued on May 16, 2012. This permit is now being submitted to EPA as a revision to the New York Regional Haze

SIP.

### 2 II. BART Analysis Summary

NRG submitted a BART analysis for the Oswe go Harbor Power facility dated August 4, 2010, with an associated engineering evaluation for NO

x 

### dated July 26, 2010. The following emission sources had previously been id entified as BART-eligible and were therefore included in the analysis:

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 capable of burning na tural gas or 1.5 percent sulfur fuel oil. 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 na tural gas or 0.75 percent sulfur fuel 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 recirc ulation (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 base line period (2007 – 2009), and neither has had a capacity factor a bove 10 percent since 2001. These operational characteristics were taken into account in this BART analysis as allowed by EPA guidance (70 FR 39167).

A summary of the analysis’ findings for each pollutant are as follows:

Boiler No. 5

• SO 2



### Oswego Unit 5 currently burns oil with a fuel sulfur limit of 1.5 percent by weight. An economic analysis indicated that switching to a lower fuel is economically 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 of 0.75 percent by weight.

Additionally, in anticipation of the Departme nt’s plans to revise its fuel sulfur requirements (and citing fuel handling advant ages of a single 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

### 3 During the baseline period of 2007 to 2009, th e annual capacity fact or for Unit 5 ranged from 0.52 percent (2009) to 2.68 percent (2007 ). The highest 12-month rolling average capacity factor during this period for either unit was 3.2 percent (Unit 5); this value was used as the basis in calculating the baseline and projected annual emissions for both units.

The baseline for NO

x 

### emissions from Unit 5 was found to be 243 tons per year (tpy). The average controlled NO

x 

### emission rate was 0.22 lb/mmBtu over this period.

The following 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 (OFA),

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

Selective 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 technically feasible control options are listed in the table below, in order of descending control effectivene ss. This table outlines the emissions that would remain after the applicati on of the control t echnology, and the average cost-effectiveness resulting from that level of emission reductions . (As previously stat ed, the cost figures

and annual emission estimates for each contro l option were calculated according to a 3.2 percent capacity factor based on hi storical 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-effectivene ss values exceed the $5,500 per ton figure established by the Department for BART. NRG states that, assuming actual capacity remains at low levels, no additional cont rols are economically feasible for BART.

NRG requests 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 th e cheapest control option from being costeffective (i.e., become lower than the $5,500 pe r 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-cal culated the threshold emission level that would prevent this option from being cost-e ffective: 405 tons per year, based on the 3.2 percent capacity factor used in the analysis. In its NO

x 

### RACT analysis submitted under separate cover on December 29, 2011, NRG used updated emissions data to revise this proposed emissions threshold to 383 tons per year.

• PM

Unit 5 presently operates with an ESP for par ticulate 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 economically infeasible. A cost analysis fo r a fabric filter unit indicated costs of approximately $40,600 per ton of PM at actu al emission rates. ESP conditioning was

### 5 also prohibitively expensive, at around $37,000 per ton. NRG also submitted an analysis for adding additional collection fields to the existing ESP, which also proved to be well

above a reasonable cost-effec tiveness, at around $60,000 per ton.

NRG back-calculated the PM emission levels that would be required to make these controls cost-effective, which proved to be mu ch higher than the leve ls seen under actual operation. NRG also notes a number of ESP improvements that have been undertaken recently. It is recommended that the current operation of the ESP constitutes BART for

PM.

Boiler No. 6

• SO 2



### Unit 6 currently has a permit limit for 0.75 percen t 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 bei ng 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 conten t greater than 0.5 percent for Units 5 and 6.

• NO

x



### Baseline emissions for Unit 6, based on actual emissions during th e 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 t hose provided under the Unit 5 section. NRG’s BART plan describes the technical feasibility of each of these control options for Unit 6. The technically feasible control options are listed in the table below, in order of descending control effectivene ss. This table outlines the emissions that would remain after the applicati on of the control t echnology, and the average cost-effectiveness resulting from that level of emission reduc tions. (Again, the co st figures and annual emission estimates for each control option we re calculated according to a 3.2 percent capacity factor based on histor ical annual hours of operation.)

### 6 Control Technology Controlled

Annual

Emissions (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 remains at low levels, no additional cont rols 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 th e cheapest control option from being costeffective (i.e., become lower than the $5,500/ton threshold). For Unit 6, the cheapest control option was to optimize combustion with burner changes and modify the OFA configuration ($17,416/ton). NRG back-calcu lated the threshold emission level that would prevent this option from being cost-e ffective: 796 tons per year, based on the 3.2 percent capacity factor used in the analysis. In its NO

x 

### RACT analysis submitted under separate cover on December 29, 2011, NRG used updated emissions data to revise this proposed emissions threshold to 665 tons per year.

• PM

Unit 6 presently operates with an ESP for par ticulate 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 economically infeasible. A cost analysis fo r a fabric filter unit indicated costs of approximately $57,300 per ton of PM at actu al emission rates. ESP conditioning was

### 7 also prohibitively expensive, at around $48,800 per ton. NRG also submitted an analysis for adding additional collection fields to the existing ESP, which also proved to be well

above a reasonable cost-effec tiveness, at around $89,000 per ton.

NRG back-calculated the PM emission levels that would be required to make these controls cost-effective, which proved to be mu ch higher than the leve ls seen under actual operation. NRG also notes a number of ESP improvements that have been undertaken recently. 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:

Boilers No. 5 and 6

• SO 2



### The Department accepts NRG’s commitment to lower the permitted No. 6 fuel sulfur limit from 1.5 percent to 0.75 percent by weight for Unit 5. The Department also accepts NRG’s proposal to retain the existing 0.75 percent limit for Unit 6.

It should be noted that the Department is pursuing a regulatory re vision to 6 NYCRR Part 225-1 to lower the acceptable fuel sulfur limit to 0.5 percent statewide (not including the New York City and lower Hudson Valley ar eas, which are already subject to more stringent limits). This revision is tentatively scheduled to be effective for 2014. The Department indicated to facility owners th at the revisions may supersede BART limits such as those proposed by NRG for Units 5 and 6. NRG has committed to future purchases of oil with a sulfur content no higher than 0.5 percent for Units 5 and 6.

• NO

x



### The Department accepts NRG’s finding that no additional controls are necessary to satisfy BART for NO

x 

### for Units 5 and 6. All available control options were adequately demonstrated to be technically or economically infeasible.

NRG has proposed, and the Department is accep ting, emission limits of 383 tons per year and 665 tons per year for Units 5 and 6, resp ectively. NRG proposed these revised limits

in its NO

x 

### RACT plan, submitted to the Department December 29, 2011. (These limits were slightly more stringent than those pr oposed in the August 4, 2010 BART analysis.)

### 8 • PM

The Department accepts the current use of an ESP as BART for PM. NRG demonstrated

that alternate controls and ESP upgrades were economically infeasible. Particulate limits

of 0.1 lb/mmBtu will be retained for Units 5 and 6.