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, 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 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 

analysis of controls for sulfur dioxide, nitrogen oxides and particulate matter. This analysis 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

reasonably 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 analysis 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 analysis for the Oswego Harbor Power facility dated August 4, 2010, 

with an associated engineering evaluation for NOx dated July 26, 2010. The following emission 

sources had previously been identified as BART-eligible and are 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 natural 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 natural gas or 0.75 percent sulfur fuel oil. 

Operation commenced in 1980.

Each of these units is equipped with low NOx burners, including LN-REACH, overfire 

air (OFA) and flue gas recirculation (FGR) control for NOx 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 neither has had a capacity factor above 10 percent since 2001. These operational 

characteristics were taken into account in this BART analysis.

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

Boiler No. 5

 SO2

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 less than 1.0 

percent by weight.

Additionally, 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 

committing to purchasing no oil in the future with a sulfur content greater than 0.5 

percent for Units 5 and 6.

 NOx

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 average 
3

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 NOx emissions from Unit 5 was found to be 243 tons per year (tpy). The 

average controlled NOx emission rate was 0.22 lb/mmBtu over this period. 

The following table presents a list of the potential NOx 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 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

remains at low levels, no additional controls 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 NOx emission limit based on 

the NOx emissions level that would prevent the cheapest control option from being costeffective (i.e., become 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 analysis. NRG proposes to modify this facility’s permit to 

include a combined NOx 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 

economically infeasible. A cost analysis for a fabric filter unit indicated costs of 
5

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 

recently. It is recommended that the current operation of the ESP constitutes BART for 

PM.

Boiler No. 6

 SO2

Unit 6 currently 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.

 NOx

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 NOx emission rate was 

0.19 lb/mmBtu over this period.

Potential NOx 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 technically 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. (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 

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 controls are economically feasible for BART.

NRG requests that the existing low NOx burners, LN-REACH, OFA, and FGR be 

accepted as BART for Unit 6. NRG proposes to accept a NOx emission limit based on 

the emissions level that would prevent the 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-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 analysis. NRG proposes to modify this facility’s permit to 

include a combined NOx 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 by 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 

economically infeasible. A cost analysis for a fabric filter unit indicated costs of 
7

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 

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:

Boiler No. 5

 SO2

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, “SO2

limits for Utility Boilers”).

It should be noted that the Department is pursuing a regulatory revision 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 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.

 NOx

The Department accepts NRG’s finding that no additional controls are necessary to 

satisfy BART for NOx 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 NOx

emission limit for Unit 5. 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 Department is requiring greater detail on these cost sources and the facilityspecific 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 
8

acceptability of the proposed emission limits. Any 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

 SO2

The Department accepts the current No. 6 fuel sulfur limit of 0.75 percent by weight as 

BART for SO2. 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, “SO2 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.

 NOx

The Department accepts NRG’s finding that no additional controls are necessary to 

satisfy BART for NOx for Unit 6. 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 NOx

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 Department is requiring greater detail on these cost sources and the facilityspecific 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. Any 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.