Summary of Comments and Responses for the Primary Aluminum Reduction Plants Source Category : Risk and Technology Review, Phase II, Group 2 Advance N otice of P roposed Rulemaking (72 FR 14734, March 29, 2007)

Metals and Min erals Group Sector Policies and Program Division Office of Air Quality Planning and Standards U.S. Environment al Protection Agency

November 16 , 20092

INTRODUCTION This document provides a summary of comments received for the Advance Notice of Proposed Rulemaking (ANPR) for the Risk and Technology Review for the Primary

A luminum Reduction Plants (72 FR 14734, March 29, 2007)

. Italso includes comments on POM emissions and speciation solicited by EPA from industry after the ANPR that was needed for the emission s database to be used for future risk modeling for the proposed rule

. The EPA responses to the comments follow the comments below , as appropriate. All c ommenters are listed in Table 1. The majority of comments focused on corrections to the Natio nal Emissions Inventory (NEI) database for specific primary

aluminum reduction plants. Table 1. List of Commenters for Primary Aluminum NESHAP ANPR and

Revised Emissions Modeling Database

ANPR Commenters Commenter Number * - Commenter Affiliation 0013 Brian Galley Pechiney Plastic Packaging, Inc. 0 014 Tim Adamowicz Ormet Primary Aluminum 0 015, 0022 Sean Lane Century Aluminum 0 016 Jamie Coomes AL CAN Primary Products 0 017 Robert Strieter The Aluminum Association 0018 Keith Overcash North Carolina Department of Environment and Natural Resources 0 019 Brandy Albertson Oregon Department of Environmental Quality 0 020 David Shaw New York St ate Department of Environmental Conservation 0 021 Michael Palazzolo AL COA 0 023 Michael Palazzolo AL COA

Commenters on Revised Emissions Modeling Database 0024** Michael Palazzolo AL COA 0025** Michael Palazzolo AL COA 0026** Michael Palazzolo AL COA 0027 Michael Palazzolo AL COA 0028 Robert Strieter The Aluminum Association 0029 Steve Wright Columbia Falls Aluminum Company 0030 Michael Palazzolo AL COA * Docket numbers for these comments use the above 4 digits with the prefix: EPA
- HQ
- QAR
200 2
- 0 031
-

XXXX
. ** Test reports for sampling and anal ys is of pol ycyclic aromatic h ydrocarbons.3

NATIONAL EMISSION INVENTORY (NE I) COMMENTS General Inventory Comments Comment : All of the commenters shown in Table 1 above provided changes to the NEI database, and the m ost extensive changes were requested by Commenter 0 021 , whose compan y owns or operates 10 of the 16 primary alumi num plants in the U.S.

 Examples of changes provided by C ommenter 0 021 for the NEI database include:  I dentifying plants, potlines , and other operations that have shut down;  R emoving emission points and emissions associated with secondary aluminum product ion ; and  C orrecting stack gas parameters , stack diameters and heights, stack latitudes and longitudes

. Response : The changes provided by the commenters were reviewed, and changes were made to update the NEI based on the corrected site

- sp ecific data from the commenters, as detailed in Appendix A. We also investigated other deficiencies in the NEI database identified by the commenters and gathered information to fill in data gaps. A listing of the se other improvements made to the NEI database, in large part due to observations of reviewers and commenters, are also noted in Appendix A

. Comment : Commenters 0 017 and 0 021 claimed that the preliminary risk review incorrectl y identified HCl and mercury as key pollutants causing potential health risks from prim ary aluminum plants. The commenters noted that emissions of HCl are more commonl y associated with secondary aluminum processes, and emissions of mercury are associated with coal

- fired power plants. Response : We have confirmed that the HCl emissions in the preliminary analy sis were from secondary aluminum production, and we have removed secondary aluminum emissions from the primary aluminum database. We also confirmed that a majority of the mercury

emissions were from a coal

- fired power plant co

- located with a primary aluminum facility ; these mislabeled emissions have been removed from the modeling database

. Comment : Two commenters ( 0027, 0028 ) recommended using 100 percent utilization of capacity to estimate both “actual” and “allowable” emissions. The commenters explained that although a few plants are operating at less than 100 percent due to current economic condit ions, many are operating at 100 percent , and those that are not will increase to 100 percent in future years as economic conditions improve . Response : EPA agrees with the comm enters, since using an industry

- wide aver age of 76 percent utilization could underestimate emissions for many plants. Therefore, POM and other emission estimates will be b ased 100 percent utilization of capacity

. Comment : Commenter 0 021 stated that even with the extended comment period, there was not enough time to full y review and update the NEI database. The commenter asked that EPA not preclude the submission of supplemental data after the end of the comm ent period.4

Response : We continued to work with this commenter, as well as other industry representatives and the trade association, after the end of the comment period. The commenter continued to provide additional data from his company ’s environmental professionals, and we have incorporated these improvements into the database. As noted below, additional opportunities were provided for industry representatives to review the changes made to the database with a particular emphasis on filling in data gap s for emissions of POM species

. Polycyclic Organic Matter (POM) Comments Comment : Commenter 0 021 provided speciated data for pol yc yc lic organic matter (POM), corrected emission estimates, added emission estimates that were missing, and separated total e missions to identify

emissions from individual potlines and roof vents. Comment : Commenter 0 020 said that POM emissions were not include d for two plants in their State and asked that the POM emission estimates be added. Response : T he data provided by the commenters , above, indicated that many plants had not included emissions of POM species. EPA compiled data for PO M species for the differ e nt types of processes, developed em ission factors, and applied these factors to estimate emissions for POM species . The methodology and estimates were sent to industry rep re sentatives and the trade association for their review. R evisions were made by EPA based on their review comments, and the POM database was sent for a second review. We incorporated the few minor additional comments received from one company during the second review ( 0030 ). Comment : One c ommenter ( 0027 ) submitted test results to estimate POM emissions from horizontal stud Soderberg (HSS) plants. (See Docket Item 0025.) Response : EPA has rep laced the estimated POM emissions from the HSS plant based on the comments, since the commenter (ALCOA) has the only existing HSS plant, and the test results are specificall y for that plant. The data used previously in the EPA estimates we re from a plant that has permanentl y closed

. Comment : One commenter ( 0029 ) submitted POM estimates for vertical stud Soderberg (VSS) plant s. This facility

i s the only

VSS plant currently

operating. The data were based on several ye ars of site

- specific testing results submitted by the facility for meth yl ene chloride soluble organics (MCSO), which are the surrogate s used for POM. Response : EPA adjusted the POM estimates for vertical stud Soderberg (VSS) plant s , since this facility is the onl y VSS plant currentl y operating.5

MODELLING COMMENTS Comment : Commenter s 0 017 and 0 021 said that EPA’s use of AERMOD to evaluate risk from potline fugitive emissions is inappropriate because it does not contain or make use of the Buo yant Line and Point (BLP) s ource algorithms re quired to properl y model 300

- m long roof vents with multiple emission points. The commenter s recommended using the BLP or CALPUF models. Response : These initial ANPR results are a screening assessment . If needed, EPA will look at some facilities on a m ore refined level, such as using BLP, before we get to the final rulemaking phase of the residual risk anal ys is. Th e EPA took a similar approach for the coke ovens rulemaking to use the BLP to predict plume rise for coke batteries. Also, EPA has some strategies for entering data from line sources so that the air model represents them accuratel y: split the emissions into a group of points so that the plume rise from the hot plumes can be captured; and/or modify the NEI emission inventory

input file with a change to the model source inputs and make it as multiple area or point source release points to better represent a line source emission. RISK ASSESSMENT COMMENTS Comment: Commenters 0 017 and 0 021 stated that it was not appropriate to multipl y the aver age emission rate by

a factor of 10 to evaluate acute (1

- hr) exposures. The commenter s said that potroom control devices, paste plants and anode bake furnaces are steady state operations, emissions that do not vary much from average values, and no safety factor should be applied. However, the commenter also stated that emissions increase from potroom vents during carbon setting and metal tapping and recommended a factor of 4 to 6 times the average to estimate hourl y roof emissions. Response : The suggest ions for acute exposure factors suggested by the commenters will be used by the EPA t o develop the factors to be used in the risk anal ys is performed for the proposed rule. The initial factor used b y EPA for the ANPR risk anal ys is was a default that was co nsidered reasonable in the absence of industry

- specific information. The public will have additional opportunity

to comment on the factors used by EPA in the proposal comment period. Comment: Commenter 0 020 recommended that the risk evaluation be based on the facility ’s actual maximum emissions if not potential emissions. The commenter cited an example of one plant that reported carbonyl sulfide emissions of 173 tons per year in the 2002 NEI whereas the Toxics Release Inventory (TRI) shows 285 tons per ye ar. The commenter also said that another plant had similar stack emissions reported in both the NEI and TRI; however, the fugitive emissions in the TRIwere 20 times greater than those reported in the NEI. Response: We plan to perform more refined mod eling based on both “actual” emissions as reported b y the companies and States , and “allowable” emissions, which are the maximum emissions permitted under the current regulations. The maximum or “potential” emissions recommended b y the commenter are comparable to the allowable emission estimates.Appendix A Details of Revi sions to the NEI Datab ase for Primary Aluminum Based on ANPR Comments and Subsequent Industry Review and Comment on the Modeling Database 1. In corporated changes in emission points, sta ck characteristics, locations, etc., according to facility comments. 2. Corrected facility

names, facility

operating status, and operating parameters:  Deleted Rey

nolds (Troutdale) and Northwest Aluminum because they have permanentl y closed.  Deleted Alcan P ackaging because it is not an aluminum plant.  Updated name changes for mostly ALCOA acquisitions, and Century Aluminum.  Adjusted the capacity of the AL COA plant in Badin, NC to 60,000 metric tons/year because one of the potlines has been permanently shut d own.  Revised (upwards) the aluminum and paste plant capacities for Columbia Falls based on their comments.  Changed the tons anode per ton aluminum ratio from 0.5 to 0.57 tons anode/ton aluminum based on comments from the Aluminum Association and AL COA. 3. Ch ecked emission points for completeness, e.g., most were missing the paste plant. Added emission units that were missing.  In formation for three plants was particularl y incomplete: Columbia Falls (only one emission point entry , unidentifiable); Century A luminum in WV; and Lake Charles Carbon. EPA obtained their Title V permits and entered emission point data that were available.  Removed emissions for a paste plant at ALCOA (West) Massena, NY, because it is no longer operating since the facility now purc hases anodes from a company in Canada. 4. Reviewed and corrected the default stack characteristics for reasonableness:  Revised several default entries that had stack diameters of 0.003 ft and 5,060 ft, which did not seem reasonable.  Compiled stack charact eristics by ty pe of process and averaged them. Filled in any missing stack characteristics with the overall averages for height, temperature, diameter, and velocity . Calculated volumetric flow from diameter and linear velocity

to be consistent.  Comment er 0030 provided latitude and longitude data for potroom roof vents for several ALCOA plants. 5. Developed emission factors and estimates of POM species for the different ty pes of processes. Industry

representatives and the trade association provided review . The following changes were made based on the review comments:  Revised the POM emission estimates on 100% utilization of capacity

.  Used test results submitted by AL COA to estimate POM emissions from horizontal stud Soderberg (HSS) plants.  Adjusted the PO M estimates for Columbia Falls Aluminum’s VSS facility based on several ye ars of site

- specific testing results provided by the facility.