1 New York State Department of Environmental Conservation Best Available Retrofit Technology Determination

Facility EF Barrett Power Station

Location Hempstead, NY Nassau County Permit ID 1-2820-00553

Source Category Fossil-fuel fired steam electric plants 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 December 7, 2011. Upon completion of this public notice period, the modified permit was submitted to EPA for review on February 7, 2012. The final modified permit was issued on March 27, 2012. This permit is now being submitt ed to EPA as a revision to the New York Regional Haze SIP.2 II. BART Analysis Summary

National Grid submitted a BART analysis for the EF Barrett Power Station to the Department dated September 27, 2010. The following emission source had previously been identified as BART-eligible and was therefore included in the analysis:

Boiler No. 2 – Emission Unit U-00002; Emission Source ES002

• This unit (“Unit 2”) is a Combustion Engin eering tangentially-fired boiler rated at a maximum hat input of 1,825 mmBtu/hr. This boile r is capable of firing natural gas or oil, though it fires natural gas almost exclusively, wi th oil serving as a backup in case of gas shortages. Operation of this unit commenced in 1963.

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

• SO 2

The EF Barrett facility primarily burns natural gas, which results in negligible SO 2 emissions. The facility is currently permitte d to burn oil with a maximum sulfur content of 0.37 percent by weight under state regulati on (6 NYCRR Part 225-1). National Grid notes that this low-sulfur fuel is well below the 1.0 percent sulfur limit in oil referenced by the Appendix Y guidance, and proposes it for BART.

This unit is required to burn oil at times, as required by local reliability rule I-R5 (the “minimum oil burn” rule) which states th at “the NYS bulk power system shall be operated so that a loss of a single gas facility does not re sult in the uncontrolled loss of electric load within th e Long Island zone.” For this reason the facility is unable to accept a permit condition limiting the amount of o il burned in order to further reduce SO 2 emissions, as such a limit would detract from the operational flexibility needed to meet the reliability requirement. The amount of o il burned is a factor of load level and the number of units online, though real-time conditions may arise that require variations from the scheduled operation.

• NO x

In 2006 and 2007, National Grid began the evaluation of NO x control technologies in anticipation of future regulatory requirements (i.e. the Clean Air Interstate Rule and revisions to NO x RACT regulations). The primary t echnologies evaluated were selective catalytic reduction (SCR), selective non- catalytic reduction (SNCR), and separated overfire air (SOFA).

SCR was the first add-on technology to be evaluated because it offers the greatest potential NO x reductions. One issue with SCR tec hnology is that effectiveness degrades with non-steady state operation, a nd this unit is no longer a ba se load unit but rather a load following unit. The cost of an SCR unit for this facility was estimated at $30M. At 100 percent operation, this resu lted in an annual control cost of $12,447 per ton of NO x3 reduced. This exceeds the $5,500/ton cost th reshold established by the Department for BART.

SNCR was also investigated dur ing this time period, and had been evaluated in the mid 1990’s as well. The resulting finding was that SNCR produced benefits no greater than that of SOFA, with additiona l operational constraints. Th e ineffectiveness of SNCR (with vendor quotes of control efficiency no high er than 20 percent) was in large part due to the load-following operation of the boiler; SNCR is much mo re effective for base load units, as the temperature profile in side the boiler is held constant.

National Grid is proposing SOFA as the cont rol technology to be installed on Unit 2, to be operating by January 1, 2014. The effectivene ss of the application of SOFA had been previously determined on this boiler. National Grid is committing to NO x emission rates of 0.20 lb/mmBtu on oil and 0.10 lb/mmBtu on gas, for compliance on a 24-hour average basis. Because National Grid selected the most stringent NO x control option that was technically and economically feasible, they did not proceed with a visibility analysis.

• PM

Because Unit 2 is fired with natural gas (and low sulfur oil as backup), particulate emissions for this unit are low. An economic analysis of an elect rostatic precipitator (ESP) for this unit indicated a cost-effectiv eness of $45,500 per ton of PM removed when assuming a $17M capital cost and 100 percen t operation. National Grid notes that a baghouse would be similarly costly. National Gr id proposes that no controls be required to fulfill BART.

III. BART Determination

The Department finds that the following shall constitute BART for EF Barrett Power Station Boiler No. 2:

• SO 2

The Department accepts the current fuel sulf ur limit of 0.37 percent by weight as BART for SO 2 . This is in line with the guidance pr ovided by EPA for sulfur in fuel of 1.0 percent or less by weight (A ppendix Y, Section IV.E.4, “SO 2 limits for Utility Boilers”). EPA also notes in the BART rule that “the most appropriate contro l option for oil-fired EGUs, regardless of capacity, is to set limits on the sulfur content of the fuel oil burned in the unit” (70 FR 39133).

• NO x

The Department accepts National Grid’s comm itment to installing SOFA as BART for NO x . Other options were ruled out due to ec onomic infeasibility (SCR) or lower control efficiency (SNCR). Na tional Grid is accepting NO x emission rates of 0.20 lb/mmBtu on oil and 0.10 lb/mmBtu on gas, for compliance on a 24-hour average basis.4 • PM

The Department accepts that no controls ar e necessary for compliance with BART for PM. National Grid adequately demonstrated that potential options were economically infeasible. This boiler will continue to ope rate with a 0.1 lb/mmBtu particulate emission limit.