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

Facility Alcoa Massena Operations (West Plant)

Location Massena, NY St. Lawrence County Permit ID 6-4058-00003

Source Category Primary Aluminum Ore Reduction; Secondary Metal Production (Aluminum)

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 January 31, 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

Alcoa submitted a BART analysis for its Masse na Operations (West Plant) on September 27, 2010. Alcoa also responded to Department que stions in a letter dated October 25, 2010, and responded to additional EPA/FLM comments in a letter dated November 11, 2011. A supplemental fuel oil analysis was provided on December 15, 2011.

The following emission sources had been identif ied as BART-eligible and were therefore included in the analysis:

Aluminum Production Cells (Potlines) - Emission Unit S-00001; Emission Source SS198

• Aluminum metal is produced by electrolytic reduction of alumina in these shallow rectangular cells, or “pots.” This potline is categorized as a center work prebake-1 (CWPB-1) within EPA’s MACT regulations. The permit to construct was issued in November, 1973. The current po tline control device is a fl uidized bed system with a baghouse; the system has a 98 pe rcent capture efficiency and a PM collection efficiency of greater than 95 percent.

Anode Baking Furnace - Emission Unit S-00002; Emission Source SS78

• Anodes are manufactured in an on-site paste production plant. Alcoa has two anode bake furnaces that are commonly controlled by a single dry alumina injection system and a pulse jet baghouse. These furnaces are fueled with natural gas.

Four Package Boilers – Emission Unit B-00001; Emission Sources B0001 through B0004

• These units are four virtually identical Babc ock & Wilcox boilers fired by either natural gas or oil. (Boilers 1 and 2 are model FM2150 and boilers 3 and 4 are model FM2310.) Each boiler has one wall-fired burner which has a maximum rated heat capacity of 200 mmBtu/hr for natural gas, and approximatel y 160 mmBtu/hr for No. 6 oil using atomized

steam.

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

Potlines

• SO 2

An SO 2 control analysis was completed for this facility’s potlines on February 18, 2009 by Hatch. SO 2 emission controls were found to be economically infeasible. A limestone slurry forced oxidation scrubber (LSFO) sy stem had a cost-effectiveness of $12,623 per ton of SO 2 controlled, in excess of the $5,500 /ton threshold established by the Department for BART. Two other potential SO 2 controls were identified by Hatch: limestone slurry scrubbing with natural ox idation (LSNO) and conventional lime wet scrubbing. These similar technologies were reviewed and found to be even less costeffective. Other control options (e.g. sodi um-based scrubbing, dry sorbent injection) were also ruled out based on tec hnical or economic infeasibility.

2Alcoa points out that BART analyses comple ted for its Tennessee and Washington plants concluded that a pollution prevention limit of 3 percent sulfur in the coke used to manufacture anodes satisfies BART. BART submittals for both plants have been accepted by their respective agencies. The Massena West Plant is already committed in their Title V permit to using coke with 2.5 percent sulfur content.

• NO x

Alcoa submitted a NO x RACT plan for the Massena Ea st Plant to the Department on March 24, 2009. This plan, which was appr oved by the Department, found that no NO x control technologies were techni cally feasible for potline em ission control. This same conclusion is applicable to the Massena West Plant. All combustion modification techniques were eliminated because there are no conventional burners or combustion points to affect in an alumin um reduction cell. This plan went on to evaluate add-on NO xcontrol technologies. Both Selective Catalytic Reduction (SCR) and Selective NonCatalytic Reduction (SNCR) were deemed t echnically infeasible because exhaust gas temperature is well below the range require d for each technology; SCR requires 650oF to 750oF and SNCR requires 1,600oF to 2,200oF, while the West Plant potline exhaust temperature is approximately 170oF.

Alcoa points out that this conclusion is consis tent with the “no control” determinations for BART at its Tennessee and Washington plants.

Based on available emissions data, Alcoa ha s proposed a 50 ton per year BART limit.

• PM

Alcoa contends that the PM em ission contribution to visibility impairment is minimal. NESCAUM modeling done for the “Contributio n to Regional Haze in the Northeast and Mid-Atlantic United States” document spec ific to the Alcoa Massena West Plant indicated that its PM emissions account for a mere 0.8 percent of the facility’s visibility impact. Accounting for higher emission leve ls reported in correspondence from April, 2010, PM contribution remains minimal. (This correspondence estimated the PM emissions to account for 1.5 pe rcent of the facility’s vi sibility impact, though this assumption was based on a 1.5 percent fuel su lfur content, which is conservative; the facility actually burns oil with le ss than 1 percent sulfur content.)

The current potline control is a shaker baghous e, which has a capture efficiency of 98 percent and a PM removal efficiency of greater than 95 percent. Given the high efficiencies of the existing fl uidized bed system and baghouse and the insignificant affect of PM on the total visibility impact, Alco a proposes that the existing PM emissions control satisfies BART, with a limit of 168 tons per year, based on recent stack test data.

3Anode Baking Furnace

• SO 2

To assess SO 2 control cost, the estimate for the in stallation of an LS FO scrubber on the potline (see summary above) was scaled for inst allation on the bake furnace. Scaling was performed using ratios of exhaust flows, em ission rates and economies of scale. The scaled cost-effectiveness for LSFO installa tion on the bake furnace was estimated at $13,795 per ton of SO 2 controlled. Dry sorbent injecti on was cited as being technically infeasible.

It is noted that—similar to the SO 2 discussion for the potlines—BART proposals for Alcoa plants in Tennessee and Washington have been accepted by their respective agencies which rely on a pollution prevention lim it of 3 percent sulfur in the anode coke, a limit which Massena West already meets. The SO 2 control cost analysis completed for the Tennessee and Washington plants likewise concluded that bake furnace control was economically unreasonable.

• NO x

Similar to the discussion on NO x controls for the potline, prospective NO x emission controls have been deemed technically inf easible through a prior RACT analysis. SCR and SNCR were again ruled out due to exha ust gas temperature; the bake furnace exhausts gas at 190oF, compared to the ranges of 650-750oF (SCR) and 1,600-2,200oF (SNCR) that are required. Cost calcula tions were completed for reference, and determined that cost-effectiveness was $30,110 per ton (SCR) and $22,860 per ton (SNCR). Combustion modificatio ns were ruled out based on technical infeasibility due to the unique combustion system of this fu rnace. This “no control” conclusion is consistent with the approved BART determinations for the Alcoa Tennessee and Washington plants.

• PM

The current bake furnace control device is a dr y alumina injection system with a pulse jet baghouse, which has a control efficiency greate r than 95 percent. Alcoa re-asserts the minimal visibility impact from plant PM emissions (see pothouse PM summary). Alcoa proposes that the existing cont rol equipment satisfies BART.

Package Boilers

• SO 2

Based on a fuel oil analysis submitted to the Department on December 14, 2011, Alcoa proposes to retain its existing 1.5 percent fu el sulfur limit. Alcoa performed a cost analysis which demonstrated th at alternate levels of fuel sulfur content (i.e., 0.5 percent and 1.0 percent) were economically infeasible.

4• 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. Alcoa opted for this method in analyzing controls for its package boilers. The revised Part 227 establishes a presumptive NO x emission limit for large oil/gas-fired boilers of 0.15 lb/mmBtu.

The Massena West Plant currently operates with low NO x burners and flue gas recirculation (FGR) to control NO x emissions. Recent testing led to the establishment of emission rates of 0.08 lb/mmBtu for gas and 0.27 lb/mmBtu for oil. Alcoa therefore analyzed additional NO x control equipment to help pot entially meet the presumptive NO x RACT limit of 0.15 lb/mmBtu.

SCR and SNCR add-on controls were evaluate d for the package boilers. The estimated cost of retrofitting these four boilers was $9,950 per ton and $12,226 per ton for SCR and SNCR, respectively. These costs were under the assumption of a single add-on control system that would be sized appr opriately to be used to contro l all four boilers; individual boiler add-on control was considered, but wa s determined to be less cost-effective.

The current permitted NO x limit for the Massena West Plant is 0.30 lb/mmBtu. Alcoa proposes that this limit be retained as BART in light of no technically and economically feasible options.

• PM

A PM compliance test conducted on March 28, 2006 resulted in an emission rate of 0.045 lb/mmBtu burning No. 6 fuel oil. Additiona lly, the “Five-Factor Analysis of BART Eligible Sources – Survey of Options fo r Conducting BART Determinations” prepared by NESCAUM on June 1, 2007 indicates that presumptive PM control levels for industrial boilers is a range of 0.02 to 0.07 lb/mmBtu. The Alcoa Massena emission rate of 0.045 lb/mmBtu falls within this presumptive range.

Accordingly, given the low PM emission rate and the insignificant effect of PM on the total visibility impact, Alcoa proposes th at existing PM emi ssions satisfy BART.

III. BART Determination

The Department finds that the following shall constitute BART for the Alcoa Massena (West Plant) emission sources:

5Potlines

• SO 2

The Department accepts Alcoa’s proposal that no further controls be required as BART for SO 2 . The control options identif ied proved to be cost-prohibitive. The sulfur level in coke is limited to 2.5 percent by weight.

• NO x

The Department accepts Alcoa’s proposal that no further controls be required as BART for NO x . The recent NO x RACT plan submitted for the East Plant demonstrated the technical infeasibility of NO x control options. The existing limit of 3.0 lb/hr will be enforced, and an additional 50 ton per year BART limit has been established.

• PM

The Department accepts the existing baghouse as representing BART for PM. This unit has very high emission control rates, and th e effect of PM from the potlines on downwind visibility is minimal. A particulate em ission limit of 168 tons per year has been established.

Anode Baking Furnace

• SO 2

The Department accepts Alcoa’s proposal that no further controls be required as BART for SO 2 . Alcoa demonstrated the economic infeasibility of additional control. This decision is consistent with previous BART de terminations by other states. The existing limit of 2.5 percent sulfur-in-coke (by weight) will be retained as BART.

• NO x

The Department accepts Alcoa’s proposal that no further controls be required as BART for NO x . A previous NO x RACT plan demonstrated the technical infeasibility of NO x control options. A BART limit of 203 tons per year is being established based on projected actual emissions.

• PM

The Department accepts the existing dry alumina injection system and baghouse as representing BART for PM. Th is unit has very high emission c ontrol rates, a nd the effect of PM from the potlines on dow nwind visibility is minimal. The unit currently has a solid particulate emission limit of 0.050 grains /dscf pursuant to 6 NYCRR Part 212.4(c). An additional BART limit of 24 tons per year is being established based on projected actual emissions.

67 Package Boilers

• SO 2

The Department will retain the existing 1.5 perc ent fuel sulfur limit on residual oil burned in the package boilers. Alcoa adequately demonstrated the economic infeasibility of burning oil with a lower sulfur content.

It should also 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 ar eas, which are already subject to more stringent limits). Th is revision is tentatively schedul ed to be effective for 2014, and would supersede Alcoa’s current limit of 1.5 percent.

• NO x

The Department accepts the current controls (low NO x burners, FGR) as representing BART for NO x . Additional control options were demonstrated as economically infeasible. The existing limit of 0.30 lb/mmBtu will be retained as BART.

• PM

The Department accepts Alcoa’s recommendati on that current opera tion with no control be considered BART for PM. The existing limit of 0.10 lb/mmBtu will be retained as BART.