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

Facility Arthur Kill Generating Station

Location Staten Island, NY Richmond County
Permit ID 2-6403-00014

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 Ne w York State’s Environmental Notice Bulletin on December 28, 2011. Upon completion of this pub lic notice period, the modified permit was submitted to EPA for review on February 2, 2012. The final modified permit was issued on March 20, 2012. This permit is now being submitt ed to EPA as a revision to the New York Regional Haze SIP.

1II. BART Analysis Summary

NRG submitted a BART analysis for the Arthur Kill Generating Station, dated August 4, 2010. The following emission source had been establ ished as BART-eligible and was therefore included in the analysis:

Boiler No. 30 – Emission Unit A-K0001; Emission source 00030

• This unit is a Combustion Engineering tangentia lly-fired boiler, rated at 5,502 mmBtu/hr. It is classified as a “very large boiler,” and has the capability to bur n natural gas or No. 6 oil, though it has fired exclusivel y natural gas for the last 10 y ears. Operation of this unit commenced in June, 1969.

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

• SO 2

In Appendix Y of 40 CFR Part 51, “Guidelines for BART Determinations Under the Regional Haze Rule,” EPA presents presump tive limits for sulfur dioxide for utility boilers. EPA states that “[y]ou must requi re 750 MW power plants to meet specific
control levels for SO 2 of either 95 percent control or 0.15 lb/mmBtu, for each EGU greater than 200 MW that is currently unc ontrolled...”

Arthur Kill Unit 30 has only burned gas for the past 10 years and emits SO 2 at an average rate of 0.0006 lb/mmBtu, well below EPA’s pres umptive level. NRG proposes that the fuel currently being burned be accepted as BA RT. NRG proposes to revise its permit limit equal to the New York City sulfur in fuel limit of 0.3 percent or 0.3 lb/mmBtu for BART purposes.

• NO
x

The Department recently revised its NO
x RACT regulations under 6 NYCRR Part 227 and, because of the common $5,500 per ton thre shold and similarity in the evaluation methodology, allowed BART-eligible facilities to fulfill NO
x RACT and NO
x for BART through one common demonstration.

The revised Part 227 establishes a presumptive NO
x emission limit for large oil/gas-fired
boilers of 0.15 lb/mmBtu. The annual av erage measured rate for Unit 30 is 0.088
lb/mmBtu. Unit 30 achieves this rate thr ough the application of existing combustion controls. NRG proposes to revise the perm it for Unit 30 to meet this new presumptive
RACT limit of 0.15 lb/mmBtu on a 24-hour av erage during the ozone season and 30-day rolling average during the non-ozone season.

• PM

NRG investigated the installation of an elec trostatic precipitator (ESP) and a baghouse to control PM emissions. Scrubbing systems were not analyzed, as these were assumed to

23 have greater costs with no additional PM re ductions. The total annual costs were found to be approximately $3.98M for the ESP and $4.25M for the baghouse. Using the
maximum 12-month PM mass over the last five years (329 tons) as a basis, and assuming these units achieve 99.9 percent capture and co ntrol, the cost eff ectiveness would be greater than $12,000 per ton for each control technology. NRG therefore requests that current operations be accepted as BART.

NRG calculated that an ESP operating at 99.9 percent—the cheaper of the two control options—would be cost-effective when Unit 30 emits 724 tons per year (tpy). NRG initially proposed this as the PM limit for Un it 30; later, NRG realized the unit is actually capable of emitting only 359 tpy at full operati on. NRG proposes to accept a 359 tpy permit limit to comply with BART.

III. BART Determination

The Department finds that the following sha ll constitute BART for Arthur Kill Generating
Station Boiler No. 30:

• SO 2

The Department finds that the current opera tion of Unit 30 is adequate as BART, and easily meets the presumptive limit established by EPA in Appendix Y. The Department is modifying Arthur Kill’s permit to include EPA’s presumptive SO 2 emission limit of 0.15 lb/mmBtu, and is also addi ng a stipulation that Unit 30 w ill fire exclusively natural gas to maintain low SO 2 emissions.

• NO
x

The Department is approving a BART NO
x limit of 0.15 lb/mmBtu, based on a 24-hour average during the ozone season and 30-day ro lling average during the non-ozone season.

• PM

The Department accepts that current ope rations represent BART for PM. NRG adequately determined that potential PM cont rols were not economically feasible. The Department is accepting the proposed 359 tpy limit.