National Emission Standards for Hazardous Air Pollutants from the

Portland Cement Manufacturing Industry

Response to Comments Received on Proposed Rule

Published on May 06, 2009, 74FR 21135

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

Metals and Minerals Group

Research Triangle Park, NC 27711

August 6, 2010
i

Table of Contents

1.0 Introduction..........................................................................................................................1

2.0 Proposed Amendments to the Current NESHAP from Portland Cement 

Manufacturing Industry .....................................................................................................34

2.2 General.................................................................................................................. 34

2.2.1 Support...................................................................................................... 34

2.2.2 Oppose ...................................................................................................... 34

2.3 Overall Approach to Setting MACT Floor Limits................................................ 35

2.3.1 Variability and Adequacy of Data ............................................................ 35

2.3.2 Pollutant-by-Pollutant MACT Floors....................................................... 40

2.3.3 Lowest Emitters Versus Best Performers................................................. 43

2.3.4 Top 5 versus 12 Percent............................................................................ 46

2.3.5 Area Sources in HCL Floor Development................................................ 47

2.3.6 Legal ......................................................................................................... 48

2.3.7 Format of Emission Limits....................................................................... 55

2.3.8 Other ......................................................................................................... 58

2.4 General Legal Issues............................................................................................. 58

2.4.1 Subcategorization...................................................................................... 58

2.4.2 Fly Ash Ban .............................................................................................. 60

2.4.4 Other ......................................................................................................... 61

2.5 Mercury Standards................................................................................................ 61

2.5.1 Legal Issues............................................................................................... 61

2.5.2 Adequacy of Floor Determinations (Existing and New) .......................... 66

2.5.3 Beyond the Floor Determinations............................................................. 74

2.5.4 Compliance Assurance.............................................................................. 74

2.5.4.1 Performance Specification 12A, 12B, and Procedure 5 .................. 82

2.5.5 Impacts.................................................................................................... 101

2.6 THC Standards.................................................................................................... 110

2.6.1 Legal Issues............................................................................................. 110

2.6.2 Adequacy of Floor Determinations (Existing and New) ........................ 111

2.6.4 Compliance Assurance............................................................................ 119

2.6.5 Impacts.................................................................................................... 127

2.6.6 Other ....................................................................................................... 131

2.7 HCl Standards..................................................................................................... 131
ii

2.7.1 Legal Issues............................................................................................. 131

2.7.2 Adequacy of Floor Determinations (Existing and New) ........................ 135

2.7.4 Compliance Assurance............................................................................ 138

2.7.5 Impacts.................................................................................................... 146

2.8 PM Standards...................................................................................................... 151

2.8.1 Legal Issues............................................................................................. 151

2.8.4 Compliance Assurance............................................................................ 158

2.8.5 Impacts.................................................................................................... 174

2.8.6 Other ....................................................................................................... 176

2.9 Compliance Dates............................................................................................... 178

2.10 Startup, Shutdown, Malfunction (SSM) ............................................................. 180

2.11 Economic Impacts............................................................................................... 186

2.12 Environmental Justice......................................................................................... 208

2.13 Open Clinker Piles.............................................................................................. 210

2.14 Crushing Operations ........................................................................................... 212

2.15 Coal Mills............................................................................................................ 212

2.16 Compliance Assurance........................................................................................ 214

2.16.1 Flow Rate Monitoring............................................................................. 214

2.16.2 Kiln Feed/Clinker Production................................................................. 214

2.16.3 Electronic Reporting ............................................................................... 216

2.16.4 Other ....................................................................................................... 216

2.17 Other – Miscellaneous Comments...................................................................... 219

List of Tables

1-1. List of Commenters on Proposed Amendments to the Current NESHAP from the 

Portland Cement Manufacturing Industry, Proposed May 06, 2009 (74 FR 21135)...........2
iii

Acronyms and Abbreviations

μg micrograms

ACFM actual cubic feet per minute

ACI activated carbon injection

ASTM American Society for Testing and Materials

AWMA Air and Waste Management Association

BACT best available control technology

BART best available retrofit technology

BAT best available technology

BLD bag leak detector

BLDS bag leak detection system

BOD biochemical oxygen demand

BTEX benzene, toluene, ethylbenzene, xylene

CAA Clean Air Act

CAM compliance assurance monitoring

CAMR Clean Air Markets Rule

CARB California Air Resources Board

CASAC Clean Air Scientific Advisory Committee

CD calibration drift

CEMS continuous emission monitoring system

CIBO Council of Industrial Boiler Owners

CKD cement kiln dust

CMM continuous mercury monitor

CO carbon monoxide

CO2 carbon dioxide

COMS continuous opacity monitoring system

CWA Clean Water Act

D/F dioxin and furan 

DAS data acquisition system

dscf/t dry standard cubic feet per ton

dscfm dry standard cubic feet per minute

EGU coal- and oil-fired electric utility steam generating unit

EO executive order

EPA U.S. Environmental Protection Agency

EPRI Electric Power Research Institute
iv

ESP electrostatic precipitators

FID flame ionization detectors

FTIR fourier transform infrared spectroscopy

GACT generally available control technology

GC-MS-MS gas chromatography-mass spectrometry

gr/dscf grains per dry standard cubic feet

HAP hazardous air pollutants

HCl hydrogen chloride

ISIS Industrial Sectors Integrated Solutions

lb/MWh pound per megawatt hour

lb/t pound per ton

lb/TBtu pound per trillion British thermal unit

LWS limestone wet scrubbers

MACT maximum achievable control technology

MMbtu million British thermal units

NAAQS National Ambient Air Quality Standards

NaOH sodium hydroxide

NESHAP National Emission Standards for Hazardous Air Pollutants

NIST National Institute of Standards and Technology

NOEL no observable effects level

NOx nitrogen oxides

NSPS New Source Performance Standards

NSR New Source Review

OAQPS Office of Air Quality Planning and Standards

OSW Office of Solid Waste

PCA Portland Cement Association

PCDF polychlorinated dibenzofuran

PH/PC preheater/precalciner

PM particulate matter

PM2.5 PM with an aerodynamic diameter less than or equal to a nominal 2.5 μ

PMD particulate matter detectors

PMDS particulate matter detection systems

POLVITEC Polysius Environmental Technology

POM polycyclic organic matter

ppmv parts per million by volume

ppmvd parts per million by volume dry
v

PQL practical quantitation limit

PS Performance Specification

PSD Prevention of Significant Deterioration

QA quality assurance

RATA relative accuracy test audits

RCA response correlation audit

RCRA Resource Conservation and Recovery Act

RIA Regulatory Impact Analyses

RRA relative response audit

RTO regenerative thermal oxidizer

SBREFA Small Business Regulatory Enforcement Fairness Act

scfm standard cubic feet per minute

SCR selective catalytic reduction

SO2 sulfur dioxide

SO3 sulfur trioxide

SRE system removal efficiency

SSM startup, shutdown and malfunction

STMS sorbent trap monitoring system

syngyp synthetic gypsum

TDS total dissolved solids

THC total hydrocarbons

Tl thallium

TNMHC total non-methane hydrocarbons

tpd tons per day

tpy tons per year

TSS total suspended solids

UBA The Federal Environment Agency (Umweltbundesamt) Mandate and 

Organization

UPL upper prediction limit

U.S. United States

UTL upper tolerance limit

VOC volatile organic compound

μm micrometers
1

1.0 Introduction

The U.S. Environmental Protection Agency (EPA or the Agency) requested comment on 

May 06, 2009 (74 FR 21135), on a proposed amendments to the current National Emission 

Standards for Hazardous Air Pollutants (NESHAP) from the Portland Cement Manufacturing 

Industry. These proposed amendments would add or revise, as applicable, emission limits for 

mercury, total hydrocarbons (THC), and particulate matter (PM) from kilns and in-line kiln/raw

mills located at a major or an area source, and hydrochloric acid (HCl) from kilns and in-line 

kiln/raw mills located at major sources. These proposed amendments also would remove the 

following four provisions in the current regulation: the operating limit for the average hourly

recycle rate for cement kiln dust; the requirement that cement kilns only use certain type of 

utility boiler fly ash; the opacity limits for kilns and clinker coolers; and the 50 parts per million 

by volume dry (ppmvd) THC emission limit for new greenfield sources. EPA is also proposing 

standards which would apply during startup, shutdown, and operating modes for all of the 

current §112 standards applicable to cement kilns.

Finally, EPA is proposing performance specifications for use of mercury CEMS, which 

specifications would be generally applicable and so could apply to sources from categories other 

than, and in addition to, portland cement, and updating recordkeeping and testing requirements. 

A 60-day comment period (ending July 06, 2009) was initially provided for the public to submit 

comments to EPA regarding the proposed amendments. Following a request for an extension to 

the comment period, the comment period was extended to September 4, 2009.

A total of 16,055 sets of comments were received by EPA regarding the proposed information 

collection request. Some of the comment sets were signed or submitted on behalf of multiple 

commenters. Also, in some cases duplicate comment sets from the same commenter were 

submitted to EPA’s Air and Radiation Docket. Table 1-1 lists the names of the commenters, the 

commenters’ affiliations, and the Air and Radiation Docket entry number for each of the 

comment sets submitted to EPA. Some commenters also submitted supplemental information 

and data to support their comments.

This document presents EPA’s response to each substantive comment received by EPA on the 

proposed amendments. The comment summaries are grouped by topic in sections.
2

Table 1-1. List of Commenters on Proposed Amendments to the Current NESHAP from 

the Portland Cement Manufacturing Industry, Proposed May 06, 2009 (74 FR 21135)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2137 May 20, 2009 EarthJustice Mass Mailing Campaign

2138 May 21, 2009 Craig S. Campbell

Vice President, Environment and Government Affairs

Larfarge North America – Cement Division

2142 June 09, 2009 Nancy Wittenberg

Assistant Commissioner

State of New Jersey Dept of Environmental Protection

2144 June 16, 2009 A.A. Linero, Program Administrator

Special Projects Section

Florida Dept of Environmental Protection

2145 June 18, 2009 George Morris

Organizer, North Texas Environmental Meetup

2146 June 19, 2009 J. Manion, Private Citizen

2147 June 19, 2009 Multiple Comment Letters to EPA – Submission of 19 citizen 

letters

2148 June 23, 2009 E. Eggleston, Private Citizen

2149 June 26, 2009 Anonymous public comment

2150 June 26 2009 K. D. Haglund, Private Citizen

2151 June 30, 2009 Anonymous public comment

2152 June 30, 2009 Anonymous public comment

2153 June 30, 2009 Anonymous public comment

2154 June 30, 2009 Anonymous public comment

2155 June 30, 2009 Karen Nicholson, President

League of Women Voters of Texas

2156 July 09, 2009 M. Wassenich

2157 July 09, 2009 Fort Worth Mayor, Mike Moncrief

2158 July 21, 2009 Ed & Carol Soph, Private Citizens

2159 July 21, 2009 Joan Eddy, Private Citizen

2160 July 22, 2009 Ellis Gilleland, Private Citizen

2161 July 22, 2009 Liz Walley, Private Citizen

2162 July 22, 2009 Fran Gloor, Private Citizen

2163 July 22, 2009 Mary Faler, Private Citizen

2164 July 22, 2009 Anne Randolph, Private Citizen

2165 July 22, 2009 Sr. Elizabeth Riebschlaeger, Private Citizen

2166 July 22, 2009 Emily Willoughby, Private Citizen

2167 July 22, 2009 Edward and Elisabeth Bala, Private Citizens

2168 July 23, 2009 Tara West, Private Citizen

2169 July 27, 2009 Emily Bergeron, Private Citizen

2170 July 27, 2009 Christopher Ebey, Private Citizen

2171 July 27, 2009 Evelyn Shepard, Private Citizen
3

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2172 July 27, 2009 Estela Moreno, Private Citizen

2173 June 28, 2009 Fabian Mendez, Private Citizen

2174 July 28, 2009 Leyland DelRe, Private Citizen

2175 July 28, 2009 Linda Sears, Private Citizen

2176 July 28, 2009 Elaine Fassel, Private Citizen

2177 July 28, 2009 Barbara Besold, Private Citizen

2178 July 28, 2009 Mark Warford, Private Citizen

2179 July 28, 2009 Brian Dodge, Private Citizen

2180 July 28, 2009 Kym Fraher, Private Citizen

2181 July 28, 2009 Betty J. Walters, Private Citizen

2182 July 28, 2009 Barbara Fitzpatrick, Private Citizen

2183 July 29, 2009 Robert Brennan, Private Citizen

2184 July 29, 2009 Virginia Velez, Private Citizen

2185 July 29, 2009 Brenon Duff, Private Citizen

2186 July 29, 2009 Patricia Mullen, Private Citizen

2187 July 29, 2009 Virginia Catanese, Private Citizen

2188 July 29, 2009 Sabine Axt, Private Citizen

2189 July 29, 2009 V. Catanese

2190 July 29, 2009 Maureen Nealon, Private Citizen

2191 July 29, 2009 Richard McGonagle, Private Citizen

2192 July 29, 2009 James Davies, Private Citizen

2193 July 29, 2009 Althea Day, Private Citizen

2194 July 29, 2009 Tim Mullins, Private Citizen

2195 July 29, 2009 Sandy Schmidt, Private Citizen

2196 July 29, 2009 Terrence and Elizabeth McCloskey, Private Citizens

2197 July 29, 2009 Careen Jennings, Private Citizen

2198 July 29, 2009 Carolyn Bell, Private Citizen

2199 July 29, 2009 Cindy Cohen, Private Citizen

2200 July 29, 2009 Charles R Shelly, Private Citizen

2201 July 29, 2009 Tria Shaffer, Private Citizen

2202 July 29, 2009 Charles Trost, Private Citizen

2203 July 29, 2009 Mary Crider, Private Citizen

2204 July 29, 2009 Christopher Walter, Private Citizen

2205 July 29, 2009 Cynthia Crutcher, Private Citizen

2206 July 29, 2009 Paula Katz, Private Citizen

2207 July 29, 2009 Arnold Simmel, Private Citizen

2208 July 29, 2009 Carlene Meeker, Private Citizen

2209 July 29, 2009 Robert Elliott, Private Citizen

2210 July 29, 2009 Patricia Gorospe, Private Citizen
4

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2211 July 29, 2009 James Carrell, Private Citizen

2212 July 29, 2009 Tim Nistler, Private Citizen

2213 July 29, 2009 Marcia Brelsford, Private Citizen

2214 July 29, 2009 Alexis Raney, Private Citizen

2215 July 29, 2009 Myra Bailes, Private Citizen

2216 July 29, 2009 Judith Sanders, Private Citizen

2217 July 29, 2009 Maija Dravnieks, Private Citizen

2218 July 29, 2009 William Reeves, Private Citizen

2219 July 29, 2009 David McIntosh, Earthjustice

2220 July 29, 2009 Pat Westwater-Jong, Private Citizen

2221 July 29, 2009 Wayne Horlacher, Private Citizen

2222 July 29, 2009 Wendy Snyder, Private Citizen

2223 July 29, 2009 Mercedes Michalski, Private Citizen

2224 July 29, 2009 Kristen Holtvedt, Private Citizen

2225 July 29, 2009 Kathryn Rose, Private Citizen

2226 July 29, 2009 Michael Nola, Private Citizen

2227 July 29, 2009 Carol Collier, Private Citizen

2228 July 29, 2009 David Bridgeman, Private Citizen

2229 July 29, 2009 Burnell Vincent, Private Citizen

2230 July 30, 2009 Winfield Solin Coleman, Private Citizen

2231 July 30, 2009 M. Fitzsimmons, Private Citizen

2232 July 30, 2009 Sergio Monteiro, Private Citizen

2233 July 30, 2009 Liza Elliott, Private Citizen

2234 July 30, 2009 Margaret Lange, Private Citizen

2235 July 30, 2009 Marcia Maroon, Private Citizen

2236 July 30, 2009 Carla Rowton, Private Citizen

2237 July 30, 2009 Magdalena Hoersch, Private Citizen

2238 July 30, 2009 Nancy Thompson, Private Citizen

2239 July 30, 2009 Michael Ochs, Private Citizen

2240 July 30, 2009 Nasus Aransu, Private Citizen

2241 July 30, 2009 Nathan Drozd, Private Citizen

2242 July 30, 2009 Nathan Huerkamp, Private Citizen

2243 July 30, 2009 Anita Yandle, Private Citizen

2244 July 30, 2009 Lara Boeck, Private Citizen

2245 July 30, 2009 Lynne Hardesty, Private Citizen

2246 July 30, 2009 Terry Jensen, Private Citizen

2247 July 30, 2009 Maureen Porter, Private Citizen

2248 July 30, 2009 Padmaja Iyer, Private Citizen

2249 July 30, 2009 Paula Thornton, Private Citizen
5

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2250 July 30, 2009 Nancy Minges, Private Citizen

2251 July 30, 2009 Martha P. Nochimson, Private Citizen

2252 July 30, 2009 Nick Heath, Private Citizen

2253 July 30, 2009 Pat Okerlund, Private Citizen

2254 July 30, 2009 David Harris, Private Citizen

2255 July 30, 2009 Keith Wells, Private Citizen

2256 July 31, 2009 Sherman Murray, Private Citizen

2257 August 03, 2009 Rick Breckenridge, Private Citizen

2258 August 03, 2009 Christy M. Woo, Private Citizen

2259 August 03, 2009 Donna Carr, MD, Private Citizen

2260 August 03, 2009 Dot Snowden, Private Citizen

2261 August 03, 2009 Ed Dickie, Private Citizen

2262 August 03, 2009 Virginia Kilgore, Private Citizen

2263 August 03, 2009 Jane Voisard, Private Citizen

2264 August 03, 2009 Bradley Esdale, Private Citizen

2265 August 03, 2009 Joen Mein, Private Citizen

2266 August 04, 2009 Zia Shields, Private Citizen

2267 August 04, 2009 Amanda Moore, Private Citizen

2268 August 04, 2009 Laura Arntz, Private Citizen

2269 August 04, 2009 Polly Bunce, Private Citizen

2270 August 04, 2009 Linda Mulka, Private Citizen

2271 August 04, 2009 Penelope Summers, Private Citizen

2272 August 05, 2009 Angel Lugo Santiago, APCAS, Inc.

2273 August 05, 2009 Cynthia Erville, Private Citizen

2274 August 05, 2009 Arvin Eyre, Private Citizen

2275 August 05, 2009 Paul Haseman, Private Citizen

2276 August 05, 2009 Pamela Ruediger, Private Citizen

2277 August 05, 2009 Carol Edwards, Private Citizen

2278 August 05, 2009 Quilla Miralia, Private Citizen

2279 August 05, 2009 Robert Burns, Private Citizen

2280 August 05, 2009 Linda McCracken, Private Citizen

2281 August 05, 2009 Rainbow Di Benedetto, Private Citizen

2282 August 05, 2009 Randolph Worsham, Private Citizen

2283 August 05, 2009 Jerry Rosenkoetter, Private Citizen

2284 August 05, 2009 M. Kissinger, Private Citizen

2285 August 05, 2009 Pete Richardson, Private Citizen

2286 August 05, 2009 Robert Posch, Private Citizen

2287 August 05, 2009 Robin Chandler, Private Citizen

2288 August 05, 2009 Rose Bertrand, Private Citizen
6

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2289 August 05, 2009 Robert Ouradnik, Private Citizen

2290 August 05, 2009 Ann Weiner, Private Citizen

2291 August 05, 2009 Rob Sadler, Private Citizen

2292 August 05, 2009 Marjorie Rhodes, Private Citizen

2293 August 05, 2009 Salma Mushir, Private Citizen

2294 August 05, 2009 Sandy Justis, Private Citizen

2295 August 05, 2009 Sandra Carrubba, Private Citizen

2296 August 05, 2009 M.A. McDonald, Private Citizen

2297 August 05, 2009 Scott Brooks, Private Citizen

2298 August 05, 2009 Eugene L. Stackle, Baker County Economic Development

2299 August 05, 2009 Robert Marquis, Private Citizen

2300 August 05, 2009 Ray Brammer, Private Citizen

2301 August 05, 2009 Mark Lea, Private Citizen

2302 August 06, 2009 Seth Edelman, Private Citizen

2303 August 06, 2009 Steven Gaber, Private Citizen

2304 August 06, 2009 Martin Pall, Private Citizen

2305 August 06, 2009 Daniel Salomon, Private Citizen

2306 August 06, 2009 Randy Juras, Private Citizen

2307 August 06, 2009 Kristin Reed, Private Citizen

2308 August 07, 2009 Fred Osterholtz, Private Citizen

2309 August 07, 2009 Dave Kisor, Private Citizen

2310 August 07, 2009 Gretchen Goodman, Private Citizen

2311 August 07, 2009 Anne Rehm, Private Citizen

2312 August 07, 2009 Gina Giacona, Private Citizen

2313 August 07, 2009 Ginny Lentz, Private Citizen

2314 August 07, 2009 Virginia Juliano, Private Citizen

2315 August 07, 2009 Ellie McCaffrey, Private Citizen

2316 August 07, 2009 Patricia Mann, Private Citizen

2317 August 07, 2009 Georgia Yelton, Private Citizen

2318 August 07, 2009 Jan Scott, Private Citizen

2319 August 07, 2009 Patricia Heithaus, Private Citizen

2320 August 07, 2009 Irvin Uphoff, Private Citizen

2321 August 07, 2009 Linda Burlingame, Private Citizen

2322 August 07, 2009 Annie Steele, Private Citizen

2323 August 07, 2009 Iman Latifpour, Private Citizen

2324 August 07, 2009 Ian Smith, Private Citizen

2325 August 07, 2009 John Ferriday, Private Citizen

2326 August 07, 2009 Jerry Comer, Private Citizen

2327 August 07, 2009 Joan Eliasoph, Private Citizen
7

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2328 August 07, 2009 Jeremy Halinen, Private Citizen

2329 August 07, 2009 Jack Lockhart, Private Citizen

2330 August 07, 2009 Joanne Beeman, Private Citizen

2331 August 07, 2009 John Abrams, Private Citizen

2332 August 07, 2009 Susan Virostek, Private Citizen

2333 August 07, 2009 Janet Rees, Private Citizen

2334 August 07, 2009 Katherine Blum Russell, Private Citizen

2335 August 07, 2009 Judith Emerson, Private Citizen

2336 August 07, 2009 Kimberly Jarvis, Private Citizen

2337 August 07, 2009 Thomasin Kellermann, Private Citizen

2338 August 07, 2009 Mary Warren, Private Citizen

2339 August 07, 2009 Laurie Harris, Private Citizen

2340 August 07, 2009 Leah Boyd, Private Citizen

2341 August 07, 2009 Leif (Captain) Knutsen, Private Citizen

2342 August 07, 2009 Leon Tomlinson, Private Citizen

2343 August 07, 2009 Suzanne Yaeger, Private Citizen

2344 August 07, 2009 Susan Martin, Private Citizen

2345 August 07, 2009 Sandra White, Private Citizen

2346 August 07, 2009 Margo Sprenger, Private Citizen

2347 August 07, 2009 Robin Evans, Private Citizen

2348 August 07, 2009 Stephanie Hammond, Private Citizen

2349 August 07, 2009 Michael Thomas, Private Citizen

2350 August 07, 2009 Patricia Finder-Stone, Private Citizen

2351 August 07, 2009 Fran Sullivan-Fahs, Private Citizen

2352 August 07, 2009 Suzette Druzik, Private Citizen

2353 August 07, 2009 Susan Ebershoff-Coles, Private Citizen

2354 August 07, 2009 Sara Ross, Private Citizen

2355 August 07, 2009 Susan Cooper, Private Citizen

2356 August 11, 2009 Charles Schmalz, Private Citizen

2357 August 11, 2009 Hugh Curtler, III, Private Citizen

2358 August 11, 2009 Cyndi Norwitz, Private Citizen

2359 August 11, 2009 Cas Waugh, Private Citizen

2360 August 11, 2009 Doug Wood, Private Citizen

2361 August 11, 2009 Christopher Viavant, Private Citizen

2362 August 11, 2009 David Kleiman, Private Citizen

2363 August 11, 2009 David Payne, Private Citizen

2364 August 11, 2009 Rahim Shaikh, Private Citizen

2365 August 11, 2009 Barbara Dotson-Brooner, Private Citizen

2366 August 11, 2009 Donald Dougall, Private Citizen
8

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2367 August 11, 2009 David Edwards, Private Citizen

2368 August 11, 2009 Deane Lavender, Private Citizen

2369 August 11, 2009 Diane Balter, Private Citizen

2370 August 11, 2009 Catherine Carpenter, Private Citizen

2371 August 11, 2009 Donald Walker, Private Citizen

2372 August 11, 2009 Doris Cellarius, Private Citizen

2373 August 11, 2009 Dorothy Patent, Private Citizen

2374 August 12, 2009 Louise Pillai, Private Citizen

2375 August 12, 2009 Janice Jacobson, Private Citizen

2376 August 13, 2009 Dee Rossi, Private Citizen

2377 August 13, 2009 Ann Cockrell, Private Citizen

2378 August 13, 2009 D. Shoemaker, Private Citizen

2379 August 13, 2009 Diane Dubendorff, Private Citizen

2380 August 14, 2009 Barbara Fukumoto, Private Citizen

2381 August 14, 2009 Keith Bussen, Vice President/General Manager, Independent 

Concrete Pipe-St. Louis (Missouri Division)

2382 August 17, 2009 Kenneth R. Schmick, Controller, Art Wilson Company

2383 August 17, 2009 Darcy Cronin, Private Citizen

2384 August 18, 2009 Bruce Kosanovic, Private Citizen

2385 August 18, 2009 David Low, Private Citizen

2386 August 18, 2009 Deborah K. Dorsch, Private Citizen

2387 August 18, 2009 Deb Brown, Private Citizen

2388 August 18, 2009 Harold Denenberg, Private Citizen

2389 August 18, 2009 Dennis Feichtinger, Private Citizen

2390 August 18, 2009 Alex Oshiro, Private Citizen

2391 August 18, 2009 D. Johnson, Private Citizen

2392 August 18, 2009 Donna Bonetti, Private Citizen

2393 August 18, 2009 Amy Lowery, Private Citizen

2394 August 18, 2009 Ashley Holtorf, Private Citizen

2395 August 18, 2009 Anthony Drew, Private Citizen

2396 August 18, 2009 Dwight Johnson, Private Citizen

2397 August 18, 2009 Edward Janus, Private Citizen

2398 August 18, 2009 E. Clark, Private Citizen

2399 August 18, 2009 Elsa Bondar, Private Citizen

2400 August 18, 2009 Frank Spadazzi, Private Citizen

2401 August 18, 2009 Meredith Garmon, Private Citizen

2402 August 18, 2009 Gail Denemark, Private Citizen

2403 August 18, 2009 Julie Schaar, Private Citizen

2404 August 18, 2009 George Hassinger, Private Citizen
9

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2405 August 18, 2009 Gerald Daley, Private Citizen

2406 August 18, 2009 Madeline von Foerster, Private Citizen

2407 August 18, 2009 Helen Corneli, Private Citizen

2408 August 18, 2009 Jerry Best, Private Citizen

2409 August 18, 2009 Paula D. Brennecke, Private Citizen

2410 August 18, 2009 Paula Olch, Private Citizen

2411 August 18, 2009 Patrick Hall, Private Citizen

2412 August 18, 2009 James A. Pierson, Private Citizen

2413 August 18, 2009 William Bell, Private Citizen

2414 August 18, 2009 Rachael Garcia, Private Citizen

2415 August 18, 2009 William Grant, Private Citizen

2416 August 18, 2009 Roger Holmen, Private Citizen

2417 August 18, 2009 Ted Terrasas, Private Citizen

2418 August 18, 2009 Sara Bhakti, Private Citizen

2419 August 18, 2009 Sherry Lewis, Private Citizen

2420 August 18, 2009 Evan Corrales, Private Citizen

2421 August 18, 2009 Jamie Specht, Private Citizen

2422 August 18, 2009 Karen Lizars, Private Citizen

2423 August 18, 2009 Susan Curry, Private Citizen

2424 August 18, 2009 Pat Turk, Private Citizen

2425 August 18, 2009 Caryl Wolstenholme, Private Citizen

2426 August 18, 2009 John Feins, Private Citizen

2427 August 18, 2009 Trevor Sheldon, Private Citizen

2428 August 18, 2009 Colin Forwood, Private Citizen

2429 August 18, 2009 Peter Wilsnack, Private Citizen

2430 August 18, 2009 Norman F. Ramsey, Private Citizen

2431 August 18, 2009 Susan Hathaway, Private Citizen

2432 August 18, 2009 Cathy Church, Private Citizen

2433 August 18, 2009 Linda Swanson, Private Citizen

2434 August 18, 2009 George Manning, Private Citizen

2435 August 18, 2009 Vivian Layton, Private Citizen

2436 August 19, 2009 Anson Chi, Private Citizen

2437 August 19, 2009 James Conroy, Private Citizen

2438 August 19, 2009 Jim Tower, Private Citizen

2439 August 19, 2009 John Neville, Private Citizen

2440 August 19, 2009 Joan Fuhry, Private Citizen

2441 August 19, 2009 John Stifter, Private Citizen

2442 August 19, 2009 James Snively, Private Citizen

2443 August 19, 2009 James Sorrells, Private Citizen
10

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2444 August 19, 2009 Robert Summers, Private Citizen

2445 August 19, 2009 Katherine Nelson, Private Citizen

2446 August 19, 2009 Ken Bugler, Private Citizen

2447 August 19, 2009 Karen Schoemer, Private Citizen

2448 August 19, 2009 Rose Lernberg, Private Citizen

2449 August 19, 2009 Jolene Rutherford, Private Citizen

2450 August 19, 2009 Lorie Vorraro, Private Citizen

2451 August 19, 2009 Richard McBane, Private Citizen

2452 August 19, 2009 Deborah Jamini, Private Citizen

2453 August 19, 2009 Michael Spink, Private Citizen

2454 August 19, 2009 Mike Ewall, Private Citizen

2455 August 19, 2009 Lori Martell, Private Citizen

2456 August 19, 2009 M'Lou Christ, Private Citizen

2457 August 19, 2009 Michael Vinciquerra, Private Citizen

2458 August 19, 2009 Nikhil Lucas Kamat, Private Citizen

2459 August 19, 2009 Joy Schochet, Private Citizen

2460 August 19, 2009 Hudson Ansley, Private Citizen

2461 August 19, 2009 Connie Mariottini, Private Citizen

2462 August 19, 2009 Doug Gawoski, Private Citizen

2463 August 19, 2009 Don Brennecke, Private Citizen

2464 August 19, 2009 Steven Calender, Private Citizen

2465 August 19, 2009 Evelyn Callaghan, Private Citizen

2466 August 19, 2009 Gerrit Crouse, Private Citizen

2467 August 19, 2009 Gregory and Renate Syme, Private Citizens

2468 August 19, 2009 Wanda Nichols, Private Citizen

2469 August 19, 2009 Jeffrey Peck, Private Citizen

2470 August 19, 2009 Alan Rosenthal, Private Citizen

2471 August 19, 2009 Anneta Buster, Private Citizen

2472 August 19, 2009 Janet Foster, Private Citizen

2473 August 19, 2009 Kevin Scott, Private Citizen

2474 August 20, 2009 Jon Halstein, Private Citizen

2475 August 20, 2009 Julia Sendor, Private Citizen

2476 August 20, 2009 David Price, Member of US Congress

2477 August 20, 2009 Jim (Surname illegible), Private Citizen

2478 August 20, 2009 Kenneth H. Baker, Private Citizen

2479 August 20, 2009 Martha B. Anderson, Private Citizen

2480 August 20, 2009 Ted Ferrioli, Oregon State Senator District 30

2481 August 20, 2009 Winnie Chang, Private Citizen

2482 August 20, 2009 Marjorie Rogalski, Private Citizen
11

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2483 August 20, 2009 MaryJane Barnes, Vice President, Lar-Ken Concrete Products, 

Inc

2484 August 20, 2009 Howard Marica Miller, Private Citizen

2485 August 20, 2009 Peter Sullivan, Private Citizen

2486 August 20, 2009 Patricia Mena, Private Citizen

2487 August 20, 2009 Steven Skal, Private Citizen

2488 August 20, 2009 Amy Mall, Private Citizen

2489 August 20, 2009 Susan Innes, Private Citizen

2490 August 20, 2009 Tom Matarrese, Private Citizen

2491 August 20, 2009 Wilma Bradbeer, Private Citizen

2492 August 20, 2009 Jo Greenwald, Private Citizen

2493 August 20, 2009 Beth Stewart, Private Citizen

2494 August 20, 2009 Robert Mazairz, Private Citizen

2495 August 20, 2009 Sharon Keys, Private Citizen

2496 August 20, 2009 Amanda Gerwig, Private Citizen

2497 August 20, 2009 Barb Cole, Private Citizen

2498 August 21, 2009 Anonymous public comment

2499 August 21, 2009 Jeff C. Calkins, Private Citizen

2500 August 21, 2009 Richard F. Burly, II, Private Citizen

2501 August 21, 2009 Mary Perry, Private Citizen

2502 August 21, 2009 Chris Barrett, Private Citizen

2503 August 21, 2009 Mel McQuarrie, Binggeli Rock Products, Inc.

2504 August 24, 2009 Wayne A. Mayer, Private Citizen

2505 August 24, 2009 J.F. Griffin, Private Citizen

2506 August 24, 2009 Sandra McDonough, President & CEO, Portland Business 

Alliance

2507 August 24, 2009 John Ledger, VP, Associated Oregon Industries (AOI)

2508 August 24, 2009 Alan Cuperus, Private Citizen

2509 August 24, 2009 Paulette M. Switzer-Tatum, Private Citizen

2510 August 24, 2009 Barbara Smith, Private Citizen

2511 August 24, 2009 Dana Allen, Private Citizen

2512 August 24, 2009 Candy Halliburton, Private Citizen

2513 August 24, 2009 Bill Himelhoch, Private Citizen

2514 August 17, 2009 Ruth Fischer, Private Citizen

2515 August 17, 2009 Reihana Robinson, Private Citizen

2516 August 17, 2009 Robert Grady, Private Citizen

2517 August 17, 2009 Robert Coleman, Private Citizen

2518 August 17, 2009 Robert Bliss, Private Citizen

2519 August 17, 2009 Robert Bruner, Private Citizen

2520 August 17, 2009 Robert Warren, Private Citizen
12

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2521 August 17, 2009 Richard Winkler, Private Citizen

2522 August 17, 2009 Scott Callaway, Private Citizen

2523 August 17, 2009 Scott Johnsen, Private Citizen

2524 August 17, 2009 Greta Bliss, Private Citizen

2525 August 18, 2009 Peg Diaz, Private Citizen

2526 August 18, 2009 Stephen Gustafson, Private Citizen

2527 August 18, 2009 Charles Shackelford, Private Citizen

2528 August 17, 2009 Shelly Thomas, Private Citizen

2529 August 18, 2009 Jeffrey Green, Private Citizen

2530 August 17, 2009 Peter Stickney, Private Citizen

2531 August 18, 2009 Rhiannon Lincoln, Private Citizen

2532 August 17, 2009 Phyllis Hasbrouck, Private Citizen

2533 August 17, 2009 Susan Chandler, Private Citizen

2534 August 17, 2009 Suzie Kidder, Private Citizen

2535 August 17, 2009 Rosemary Hicks, Private Citizen

2536 August 17, 2009 Ted Robinson, Private Citizen

2537 August 17, 2009 Tim McMullen, Private Citizen

2538 August 17, 2009 Elizabeth Kenyon, Private Citizen

2539 August 17, 2009 Thamar Wherrit, Private Citizen

2540 August 17, 2009 Don Segraves, Private Citizen

2541 August 17, 2009 David Bellos, Private Citizen

2542 August 18, 2009 Edra Bogle, Private Citizen

2543 August 18, 2009 Alan McCauley, Private Citizen

2544 August 18, 2009 Evelyn Kountoupes, Private Citizen

2545 August 17, 2009 Richard Dwyer, Private Citizen

2546 August 18, 2009 Christopher Eliot, Private Citizen

2547 August 17, 2009 Rebecca Pontikes, Private Citizen

2548 August 17, 2009 Jeanne Ellgar, Private Citizen

2549 August 18, 2009 Eric Cartier, Private Citizen

2550 August 17, 2009 Elaine Ransom, Private Citizen

2551 August 17, 2009 Maxim Fetissenko, Private Citizen

2552 August 17, 2009 David Beebe, Private Citizen

2553 August 17, 2009 Gay Kramer-Dodd, Private Citizen

2554 August 18, 2009 Mike Desmond, Private Citizen

2555 August 18, 2009 Susan Lippman, Private Citizen

2556 August 17, 2009 Richard Kipp, Private Citizen

2557 August 18, 2009 Alicia Mein, Private Citizen

2558 August 17, 2009 Robert Toon, Private Citizen

2559 August 17, 2009 Linda Mattox, Private Citizen
13

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2560 August 18, 2009 Lara Valigorsky, Private Citizen

2561 August 17, 2009 Lucille Bertuccio, Private Citizen

2562 August 17, 2009 Lisa Butterfield, Private Citizen

2563 August 18, 2009 Susan Hawes, Private Citizen

2564 August 17, 2009 William Smith, Private Citizen

2565 August 17, 2009 William Audette, Private Citizen

2566 August 18, 2009 Alice Littlefield, Private Citizen

2567 August 17, 2009 George Loveday, Private Citizen

2568 August 21, 2009 Ione Woods, Private Citizen

2569 August 17, 2009 Zorine Rinaldi, Private Citizen

2570 August 17, 2009 Marilyn Britton, Private Citizen

2571 August 18, 2009 Keith Allen, Private Citizen

2572 August 17, 2009 Lois Reborne, Private Citizen

2573 August 18, 2009 Barbara Toshalis, Private Citizen

2574 August 17, 2009 Bonnie Pilcher, Private Citizen

2575 August 18, 2009 Karen Bunkowski, Private Citizen

2576 August 17, 2009 Cindy Cox, Private Citizen

2577 July 20, 2009 Bill Cagle, Private Citizen

2578 August 17, 2009 Alyn Goldsmith, Private Citizen

2579 August 17, 2009 Barry Rein, Private Citizen

2580 August 17, 2009 Caroline Herzenberg, Private Citizen

2581 August 18, 2009 Carroll English, Private Citizen

2582 August 17, 2009 Cat Koehn, Private Citizen

2583 August 18, 2009 Charles Trebes, Private Citizen

2584 August 18, 2009 Christina Muniz, Private Citizen

2585 August 18, 2009 Greg Ciapponi, Private Citizen

2586 August 17, 2009 Doug Richardson, Private Citizen

2587 August 17, 2009 Charles Wonka, Private Citizen

2588 August 17, 2009 Anne Humphrey, Private Citizen

2589 August 17, 2009 R.H. Kroell, Private Citizen

2590 August 17, 2009 David Kleiman, Private Citizen

2591 August 17, 2009 Dawn Nelson, Private Citizen

2592 August 18, 2009 Deirdre Wilson, Private Citizen

2593 August 17, 2009 David Hucknall, Private Citizen

2594 August 17, 2009 Delcie Light, Private Citizen

2595 August 18, 2009 Donna Bonetti, Private Citizen

2596 August 17, 2009 David Lewton, Private Citizen

2597 August 17, 2009 Lenore Bentz, Private Citizen

2598 August 17, 2009 Laurel Herendeen, Private Citizen
14

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2599 August 17, 2009 Mark Robertson, Private Citizen

2600 August 17, 2009 Marlena Machol, Private Citizen

2601 August 17, 2009 Martha Burton, Private Citizen

2602 August 17, 2009 Melanie Tang, Private Citizen

2603 August 17, 2009 H. Michael Laybourn, Private Citizen

2604 August 17, 2009 Margaret Fontenot, Private Citizen

2605 August 17, 2009 Linda Griggs, Private Citizen

2606 August 17, 2009 Matthew Comber, Private Citizen

2607 August 17, 2009 Anita Trenner, Private Citizen

2608 August 17, 2009 Marie Lloyd, Private Citizen

2609 August 18, 2009 Katherine Narveson, Private Citizen

2610 August 17, 2009 George Thomas, Private Citizen

2611 August 17, 2009 Megan Stephenson, Private Citizen

2612 August 17, 2009 Gary Neu, Private Citizen

2613 August 17, 2009 Hal Nixon, Private Citizen

2614 August 17, 2009 Helen Putera, Private Citizen

2615 August 17, 2009 Jerry Best, Private Citizen

2616 August 17, 2009 Joanie Alexander, Private Citizen

2617 August 18, 2009 Judith Arcana, Private Citizen

2618 August 17, 2009 John Pierson, Private Citizen

2619 August 18, 2009 Jennifer Jackson, Private Citizen

2620 August 18, 2009 Nora Gallaher, Private Citizen

2621 August 17, 2009 Anesa Miller, Private Citizen

2622 August 20, 2009 G. Vinson Hellwig, Michigan, Co-Chair, NACAA Air Toxics 

Committee

Robert H. Colby, Chattanooga, TN, Co-Chair, NACAA Air 

Toxics Committee

2623 August 17, 2009 James Sanders, Private Citizen

2624 August 17, 2009 Janet Jones, Private Citizen

2625 August 18, 2009 Joan Wilce, Private Citizen

2626 August 17, 2009 John Thomas, Private Citizen

2627 August 17, 2009 Joseph Belisle, Private Citizen

2628 August 18, 2009 Judith Eiseman, Private Citizen

2629 August 18, 2009 Judith Gallagher, Private Citizen

2630 August 17, 2009 Kathryn Bankston, Private Citizen

2631 August 17, 2009 Keith Powell, Private Citizen

2632 August 17, 2009 Kevin Shilling, Private Citizen

2633 August 18, 2009 Angele Ellis, Private Citizen

2634 August 17, 2009 Kevin Riley, Private Citizen

2635 August 17, 2009 Catherine Harned, Private Citizen
15

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2636 August 17, 2009 Jon Krampner, Private Citizen

2637 August 18, 2009 Nicolas Pekari, Private Citizen

2638 August 22, 2009 John A. Cooper, Cooper Environmental Services LLC (CES)

2639 August 17, 2009 Ted Taylor, Private Citizen

2640 August 17, 2009 Barbara Roberts, Private Citizen

2641 August 17, 2009 Vanessa Weeks, Private Citizen

2642 August 18, 2009 Sue Bond, Private Citizen

2643 August 17, 2009 Harriet Irby, Private Citizen

2644 August 18, 2009 Thomas Martinez, Private Citizen

2645 August 17, 2009 Tom Ragouzis, Private Citizen

2646 August 17, 2009 Victoria Baker, Private Citizen

2647 August 17, 2009 Scott Ohlman, Private Citizen

2648 August 17, 2009 Paulette Bliss, Private Citizen

2649 August 20, 2009 Dave Bennett, Kaman Industrial Technologies - Ontario Oregon

2650 August 20, 2009 Neil Sulivan, Granite Concrete Co, Inc

2651 August 20, 2009 Mike Jeffries, Goat Rock Mining Corp.

2652 July 14, 2009 Mass Comment Campaign, Sponsoring Organization Unknown 

(8,715)

2653 August 23, 2009 Kenneth Carlson, C&A Equipment Company

2654 August 20, 2009 Cass R. Vanderwiele, President/Owner, Triple C. Redi-Mix

2655 August 20, 2009 Gary and Kathy Bloomer, Private Citizens

2656 August 14, 2009 Rhonda Fox, Private Citizen

2657 August 24, 2009 Wesley B. Prouty, Private Citizen

2658 July 20, 2009 Mass Comment Campaign, Sponsoring Organization Unknown 

(80)

2659 August 21, 2009 Ronald Verini, Private Citizen 

2660 August 25, 2009 John C. Colbert, Vice President and General Manager 

Automatic Wilbert Vault Co., Inc.

2661 August 25, 2009 Bob Vandecar, Business Representative and Organizer, 

International Brotherhood of Electrical Workers

2662 September 09, 2009 J. Robenolt, Private Citizen

2663 September 09, 2009 M. Minow, Private Citizen

2664 August 08, 2009 Carmelita Holland, Private Citizen

2665 August 16, 2009 Thomas Bunch, Private Citizen

2666 August 18, 2009 Heidi Martin, Private Citizen

2667 August 20, 2009 Jeff Mendes, Regional Sales Manager, Ash Grove Cement 

Company

2668 August 21, 2009 Michael A. Henigan, Private Citizen

2669 August 20, 2009 Diana L. Henigan, Private Citizen

2670 August 17, 2009 Robert J. Schreiber, Jr., President, Schreiber, Yonley & 

Associates
16

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2671 August 10, 2009 Mark Holliday, Business Manager and Financial Secretary, 

Local 701, International Union of Operating Engineers (IUOE)

2672 July 30, 2009 Dennis Dorrah, Mayor, City of Baker City, Oregon (OR)

2673 August 17, 2009 Sarita Raney, Private Citizen

2674 August 19, 2009 Herbert L. Keyser, Private Citizen

2675 August 26, 2009 Thomas Mumley, Assistant Executive Officer, San Francisco 

Bay Regional Water Quality Control Board, California EPA

2676 August 31, 2009 Robert Minister, Ash Grove Cement Company

2677 August 25, 2009 David Hayes, Private Citizen

2678 August 24, 2009 Deb Santa, Private Citizen

2679 August 24, 2009 Dennis Swaer, Private Citizen

2680 August 19, 2009 Devon Downeysmith, Private Citizen

2681 August 28, 2009 Diane Dillard, Private Citizen

2682 September 01, 2009 Jon Trygve Grey, Process Engineer, Seattle Plant, Ash Grove 

Cement Company

2683 August 28, 2009 Dr. Dick Schoech, Private Citizen

2684 August 21, 2009 J. Ding, Private Citizen

2685 August 28, 2009 Edgar and Dora Stahl, Private Citizens

2686 August 26, 2009 Edwina Allen, Private Citizen

2687 August 29, 2009 Barbara Lawrence, Private Citizen

2688 August 28, 2009 Fred Kennedy, Private Citizen

2689 August 28, 2009 Carol Fulton, Private Citizen

2690 August 28, 2009 Rollie Blackwell, Private Citizen

2691 August 28, 2009 Ruth Cook, Private Citizen

2692 August 22, 2009 Sara Freed, Private Citizen

2693 August 19, 2009 Susan Lewis, Private Citizen

2694 August 19, 2009 Sean Edmison, Private Citizen

2695 August 29, 2009 Gail Krueger, Private Citizen

2696 August 28, 2009 Gary and Christy Richards, Private Citizens

2697 August 28, 2009 Gayle E. Marshall, Private Citizen

2698 August 24, 2009 Grace Koehler, Private Citizen

2699 August 19, 2009 Holly Berkowitz, Private Citizen

2700 August 28, 2009 Howard Tubre, Private Citizen

2701 August 28, 2009 John Rath, Private Citizen

2702 August 28, 2009 John White, Private Citizen

2703 August 28, 2009 Shari Buhan, Private Citizen

2704 August 28, 2009 Ilana Shumsky, Private Citizen

2705 August 25, 2009 Shayne Vinagre, Private Citizen

2706 August 30, 2009 James Presley, Private Citizen

2707 August 26, 2009 Beth Duke, Private Citizen
17

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2708 August 24, 2009 Sheila Boester, Private Citizen

2709 August 20, 2009 Sheriel Hubble, Private Citizen

2710 August 19, 2009 Sandra Sawyer, Private Citizen

2711 August 29, 2009 Carolina Vornberg, Private Citizen

2712 August 25, 2009 Jane Janzen, Private Citizen

2713 August 24, 2009 Bernard Feiss, Private Citizen

2714 August 24, 2009 Jay Krajic, Private Citizen

2715 August 27, 2009 Jean Benedict, Private Citizen

2716 August 24, 2009 Jean Gonzales, Private Citizen

2717 August 28, 2009 Jonathan Grimm, Private Citizen

2718 August 28, 2009 Judith Godinez, Private Citizen

2719 August 25, 2009 Betsy Goodman, Private Citizen

2720 August 26, 2009 Mike Chandler, Private Citizen

2721 August 24, 2009 Michael Lanza, Private Citizen

2722 August 25, 2009 Jean Maryborn, Private Citizen

2723 August 26, 2009 Michael Rutledge, Private Citizen

2724 August 28, 2009 Mona Kandeler, Private Citizen

2725 August 30, 2009 Mona Mehdy, Private Citizen

2726 August 24, 2009 Muriel Roberts, Private Citizen

2727 August 20, 2009 Michele Mason, Private Citizen

2728 August 29, 2009 Nancy Holcomb, Private Citizen

2729 August 28, 2009 Elizabeth Carman, Private Citizen

2730 August 28, 2009 Stacy Alaimo, Private Citizen

2731 August 19, 2009 Steven Libby, Private Citizen

2732 August 28, 2009 Stewart Snider, Private Citizen

2733 August 25, 2009 Susan McKean, Private Citizen

2734 August 26, 2009 Susan Norton, Private Citizen

2735 August 30, 2009 Tamara Teague, Private Citizen

2736 August 22, 2009 Anthony Wilson, Private Citizen

2737 August 25, 2009 Thomas Heinrich, Private Citizen

2738 August 25, 2009 Todd Davis, Private Citizen

2739 August 28, 2009 Charles Hobbs, Private Citizen

2740 August 24, 2009 Tom Godard, Private Citizen

2741 August 19, 2009 Patricia M. Williams, Private Citizen

2742 August 28, 2009 Virginia Gewax, Private Citizen

2743 August 19, 2009 Kathleen Wagner, Private Citizen

2744 August 29, 2009 Wayne Greene, Private Citizen

2745 August 28, 2009 Jeffrey Jacoby, Private Citizen

2746 August 24, 2009 Jeffrey Davis, Private Citizen
18

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2747 August 29, 2009 Jo Adams, Private Citizen

2748 August 24, 2009 John Laz, Private Citizen

2749 August 29, 2009 Olive Hershey, Private Citizen

2750 August 22, 2009 Candia McNeal, Private Citizen

2751 August 25, 2009 Pam Colesworthy, Private Citizen

2752 August 24, 2009 Paul Martin, Private Citizen

2753 August 19, 2009 Philip K. Kreitner, Private Citizen

2754 August 24, 2009 Peggy Jordan, Private Citizen

2755 August 28, 2009 Peggy Sakach, Private Citizen

2756 August 24, 2009 Perry Brown, Private Citizen

2757 August 19, 2009 Arvin Eyre, Private Citizen

2758 August 28, 2009 Raymond E. Bowden, Private Citizen

2759 August 25, 2009 Regi Teasley, Private Citizen

2760 August 28, 2009 William Blackley, Private Citizen

2761 August 22, 2009 Caryl Wolstenholme, Private Citizen

2762 August 28, 2009 Dr. Yvonne Hansen, Private Citizen

2763 August 24, 2009 Charles Trost, Private Citizen

2764 August 24, 2009 Claire Casey, Private Citizen

2765 August 25, 2009 Craig Willey, Private Citizen

2766 August 21, 2009 Paige Zhang, Private Citizen

2767 August 29, 2009 Dan Smith, Private Citizen

2768 August 28, 2009 Vic Gilliam, House District 18, Oregon House of 

Representatives

2769 August 28, 2009 Carol Coulston, Private Citizen

2770 August 20, 2009 Dan Stabel, Private Citizen

2771 August 24, 2009 David Anderson, Private Citizen

2772 August 19, 2009 Alan Mahrenholz, Private Citizen

2773 August 28, 2009 George L. Gilman, State Representative, District 55, Oregon 

House of Representatives

2774 August 24, 2009 Andrea Sparrow, Private Citizen

2775 August 28, 2009 David Davidson, Private Citizen

2776 August 28, 2009 Jenoa Ingram, Oregon Independent Aggregate Association 

(OIAA)

2777 August 30, 2009 John E. Huffman, State Representative, House District 59

2778 August 31, 2009 Norma Job, Private Citizen

2779 undated Patrick Flanagan, Private Citizen

2780 July 20, 2009 Brittni Philips, Private Citizen

2781 August 31, 2009 Donna Piercy, Private Citizen

2782 July 20, 2009 William Edgar, Private Citizen

2783 July 22, 2009 Tim Burrows, Private Citizen
19

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2784 July 28, 2009 Hilary Cox, Private Citizen

2785 August 31, 2009 Wendy Hosman, Private Citizen

2786 September 1, 2009 Deborah Behles, Staff Attorney

Lucas Williams, Graduate Fellow

Environmental Law and Justice Clinic at Golden Gate 

University on behalf of West Valley Citizens Air Watch and 

Bayview Hunters Point Community Advocates

2787 August 31, 2009 Daniel Kocurek, Private Citizen

2788 August 31, 2009 Jerry R. Boggs, Private Citizen

2789 August 31, 2009 Charles Morgan, Private Citizen

2790 August 31, 2009 Jensie Madden, Private Citizen

2791 August 28, 2009 Jules Dylan Stuer, Private Citizen

2792 August 24, 2009 Julie Grove, Private Citizen

2793 August 24, 2009 Karen Pfleger, Private Citizen

2794 August 30, 2009 Kathleen Tanaka, Private Citizen

2795 August 24, 2009 Kathy Patlovich, Private Citizen

2796 August 27, 2009 Ken Dunbar, Private Citizen

2797 August 25, 2009 Laura Hartman, Private Citizen

2798 August 19, 2009 Kim Young, Private Citizen

2799 August 24, 2009 Betsy Bridge, Private Citizen

2800 August 26, 2009 Kirsten Severud, Private Citizen

2801 August 24, 2009 Laura Todd, Private Citizen

2802 August 19, 2009 Leonard and Nancy Deadman, Private Citizens

2803 August 25, 2009 Leonora Midgley, Private Citizen

2804 August 24, 2009 Leslie Bradshaw, Private Citizen

2805 August 28, 2009 Linda Knowles, Private Citizen

2806 August 24, 2009 Lorna Emdy, Private Citizen

2807 August 20, 2009 Mary Ann Lambert, Private Citizen

2808 August 25, 2009 Marlene Strong, Private Citizen

2809 August 28, 2009 Martha Clinkscale, Private Citizen

2810 August 31, 2009 Mayor Joe Dominick and City of Ontario City Council, City of 

Ontario, Oregon

2811 August 27, 2009 Cliff Bentz, State Representative, District 60, Oregon State 

House of Representatives

2812 August 27, 2009 Randall B. Hampton, President, Hampton's Inc. DBA Rogers 

Asphalt Paving Company

2813 August 28, 2009 Art Wilson, Cal-CM Plus

2814 August 28, 2009 Wendt, Private Citizen

2815 August 25, 2009 Flack, Private Citizen
20

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2816 September 18, 2009 Martha H. Keating, Director of Research Translation, Nicholas 

School of Environment, Duke University on behalf of the 

Children's Environmental Health Initiative (CEHI)

Attachment – Letter

2817 August 21, 2009 Gould, Private Citizen

2818 August 28, 2009 Faidley, Private Citizen

2819 August 24, 2009 Richard Heimsch, Private Citizen

2820 August 28, 2009 Richard Wilder, Private Citizen

2821 August 24, 2009 Rob Santa, Private Citizen

2822 August 28, 2009 Robert Burns, Private Citizen

2823 April 2009 Supporting Statement for NESHAP for Portland Cement Plants 

(40 CFR part 63, subpart LLL) – Not a public comment

2824 September 18, 2009 E. Rafacz, Private Citizen

2825 August 25, 2009 Robsert Vestal, MD, Private Citizen

2826 August 24, 2009 Rocci Johnson, Private Citizen

2827 August 24, 2009 Roger Harrer, Private Citizen

2828 September 18, 2009 Al Armendariz, Ph.D., Private Citizen

2829 September 18, 2009 Al Armendariz, Private Citizen

2830 September 18, 2009 Gary A. Molchan, Vice President, Environmental Affairs, 

Essroc Cement Corporation

2831 September 18, 2009 Jan Alexander, Minerals Policy Coordinator, Eastern Oregon 

Mining Association (EOMA)

2832 September 3, 2009 Howard L. Gilberg, Guida, Slavich & Flores on behalf of the 

Tile Council of North America, Inc. (TCNA)

2833 September 18, 2009 Laura Skaer, Executive Director, Northwest Mining Association 

(NWMA)

2834 September 18, 2009 Geoffrey R. Gisler, Staff Attorney, Southern Environmental 

Law Center (SELC)

2835 September 18, 2009 James R. Roewer, Executive Director, Utility Solid Waste 

Activities Group (USWAG)

2836 September 18, 2009 James C. Morris III, Thompson & Knight LLP on behalf of 

Eagle Materials, Inc.

2837 September 4, 2009 John A. Cooper and Drag A. Petterson, Cooper Environmental 

Services, LLC (CES)

2838 September 4, 2009 John A. Cooper and Krag A. Petterson, Cooper Environmental 

Services, LLC (CES)

2839 September 18, 2009 Alva R. Mascall, et al., Ash Grove Cement Company

2840 September 18, 2009 T. Kerry, Private Citizen

2841 September 18, 2009 David Perkins, Corporate Director, Communications and 

Government Affairs, TXI Operations, LP

2842 September 18, 2009 Andrew M. Cuomo, Attorney General, State of New Yhork et 

al.
21

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2843 September 21, 2009 Susie Devergranne, Chairperson, Davenport Environmental 

Health Coalition

2844 September 21, 2009 Patrick M. Raher, Hogan and Hartson, LLP

On behalf of National Cement Company (NCC)

2845 September 21, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA)

2846 September 21, 2009 Robert D. Bessette, President, Council of Industrial Boiler 

Owners (CIBO)

2847 September 2, 2009 C. Puljan, Private Citizen

2848 September 21, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA)

2849 September 4, 2009 Jim Griffin, Senior Director, Regulatory and Technical Affairs, 

American Chemistry Council (ACC)

2850 September 21, 2009 Robert J. Kaleel, Manager, Air Quality Planning Section, 

Bureau of Air, Illinois Environmental Protection Agency 

(Illinois EPA)

2851 September 21, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA) [Part 3 Daily Chart]

2852 September 01, 2009 Chuck Buchanan, Private Citizen

2853 September 01, 2009 David Baker, Private Citizen

2854 September 01, 2009 John Unger, Private Citizen

2855 September 21, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA)

Part 4: Appendix 2 to Appendix 12

2856 September 01, 2009 Louis T. Scharbrough, Private Citizen

2857 September 01, 2009 Swanna Tanger, Private Citizen

2858 September 21, 2009 Edward X. Junia, Esquire, Attorney-at-Law

2859 September 21, 2009 Craig S. Cambell, Vice President, Environmental & 

Government Affairs, Lafarge North America - Cement Division

2860 September 21, 2009 Anne Hedges, Program Director, Montana Environmental 

Information Center (MEIC)

2861 August 27, 2009 Bruce Schacht, Environmental Engineer, Columbia Steel 

Casting Co., Inc

2862 September 01, 2009 Basil D. Jacobson, Vice President, Concrete Planet Manager, 

United Materials of Great Falls, Inc.

2863 September 04, 2009 Curtis Lesslie, P.E., Director of Environmental Affairs, Ash 

Grove Cement Company

2864 September 08, 2009 Hector Ybanez, Holcim (US), Inc.

2865 September 01, 2009 W.C. Jacobson, Private Citizen

2866 September 01, 2009 T. Kerby, Private Citizen

2867 September 04, 2009 Alvaro A. Linero, P.E., Program Administrator, Special Projects 

Section, Bureau of Air Regulation, Division of Air Resources 

Management, Florida Department of Environmental Protection
22

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2868 September 21, 2009 Christopher Lish, Private Citizen

2869 September 02, 2009 Scott Burns, Chief Executive Officer (CEO), BURNCO Rock 

Products Ltd (BURNCO)

2870 September 03, 2009 Bryan Brendle, Director, Energy and Resources Policy, 

National Association of Manufacturers (NAM)

2871 September 03, 2009 B. Johnson, Private Citizen

2872 September 03, 2009 Geoff Brosseau, Executive Director, Bay Area Stormwater 

Management Agencies Association (BASMAA)

2873 September 22, 2009 Andy O'Hare, Portland Cement Association (Part 5: Appendix 

13 and Appendix 14)

2874 September 04, 2009 Daniel B. Nugent, Vice President, Environmental Affairs, Buzzi 

Unicem USA, Inc.

2875 September 04, 2009 E.X. Junia, Private Citizen

2876 September 04, 2009 F. Pinto, Private Citizen

2877 September 01, 2009 Raymond L. Calkins, DVM

Lynn M. Calkins

Private Citizens

2878 September 05, 2009 Charles Hofmann, MD

2879 September 04, 2009 John F. Chadbourne, Ph.D., President, Chadbourne 

Environment & Safety Programs, L.L.C. (CESP)

2880 September 01, 2009 Richard Angstrom, Oregon Concrete & Aggregate Producers 

Association (OCAPA)

2881 September 04, 2009 Mariah S. Chen, Private Citizen

2882 September 04, 2009 Virgil L. Thomas, Private Citizen

2883 September 01, 2009 Lisa Kerby, Private Citizen

2884 September 02, 2009 Judge Dan P. Joyce, Commissioner Louis Wettstein

Commissioner Jim Nakano, Malheur County Court

2885 September 01, 2009 Norma Job, Private Citizen

2886 September 01, 2009 Anonymous Public Comment

2887 September 04, 2009 Peter T. Kimmel, Vice President (VP), Operations, Armstrong 

Cement & Supply Co.

2888 September 04, 2009 Doug Roark, Manager, Environmental and Process, GCC of 

America

2889 September 09, 2009 John Richards, Ph.D., P.E., Air Control Techniques, P.C.

2890 September 04, 2009 Susan Miller, Vice President, Environmental, Health & Safety, 

Brick Industry Association (BIA)

Terry Schimmel, BIA MACT Task Force Lead, Vice President, 

Manufacturing, Boral Bricks

2891 September 04, 2009 Joseph Otis Minott, Executive Director, Clean Air Council

2892 September 04, 2009 Scott Trainor, General Manager, Thiessen Team USA Inc.

2893 September 04, 2009 Joyce M. Eden et al., West Valley Citizens Air Watch 

(WVCAW) ad Monica Wilson, Global Alliance for Incinerator 

Alternatives (GAIA)
23

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2894 September 03, 2009 Frank Schaedlich, Vice President Research & Development, 

Tekran Instruments Corporation

2895 September 03, 2009 Jennifer Mesaros, Private Citizen

2896 September 04, 2009 Lee Jamison, Private Citizen

2897 September 05, 2009 Lindsey L. Hrizuk, Private Citizen

2898 September 09, 2009 Avinash Kar, Natural Resources Defense Council (NRDC) et al.

2899 September 04, 2009 Kevin Blankenship, Private Citizen

2900 November 12, 2009 Timothy L. Matz, Director, Environmental Affairs, Lehigh 

Hanson, Inc. (Lehigh Cement Company)

2901 September 09, 2009 Melvin E. Keener, Ph.D., Executive Director, Coalition for 

Responsible Waste Incineration (CRWI)

2902 September 04, 2009 Jacqueline K. Clark, Private Citizen

2903 September 04, 2009 Charles Simpson, Mayor, City of Huntington, Oregon (OR)

2904 September 01, 2009 Alan Finch, Private Citizen

2905 September 01, 2009 James Walton and Rebecca L. Wood, Private Citizens

2906 September 04, 2009 Kelly Campbell BA, Executive Director, Joseph Miller Ph.D., 

and Susan Katz M.D., Members, Board of Directors and Maye 

Thompson RN, Ph.D., Environmental Health Program Director, 

Oregon Chapter of Physicians for Social Responsibility

2907 September 04, 2009 Allie Sheffield, Chair, Committee on Titan Cement, Pender 

Watch and Conservancy

2908 September 04, 2009 Bishop Titus B. Deas, Jr., National Education and Outreach 

Spokesperson, EmPower Consumers

2909 September 04, 2009 Susan Falzon, Friends of Hudson (FoH)

2910 September 04, 2009 Verie C. Martz, Vice President Engineering and Environment, 

Salt Riber Materials Group (SRMG), on behalf of Phoenix 

Cement Company

2911 September 04, 2009 Sierra Club et al.

2912 September 04, 2009 Adam W. Olivieri, Dr. PH, P.E., Program Manager, Santa Clara 

Valley Urban Runoff Pollution Prevention Program 

(SCVURPPP)

2913 September 04, 2009 Natural Resources Defense Council (NRDC) et al.

2914 September 04, 2009 Michael R. Benoit, Executive Director, Cement Kiln Recycling 

Coalition (CKRC)

2915 September 09, 2009 Lee B. Zeugin and Lauren E. Freeman, Hunton & Williams 

LLP,

on behalf of 

Utility Air Regulatory Group (UARG)

2916 September 10,2009 Jim Griffin, Senior Director, Regulaotyr and Technical Affairs, 

American Chemistry Council (ACC)

2917 September 10, 2009 Michael Stewart, President & CEO (Chief Executive Officer), 

Texas Aggregates & Concrete Association (TACA)

2918 September 04, 2009 Lane H. Smith, Manager, Environmental Projects, Giant 

Cement Holding, Inc. (GCHI)
24

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2919 September 10, 2009 Dick Pedersen, Director, Oregon Department of Environmental 

Quality (ODEQ)

2920 September 01, 2009 Hurchel Young, Instrument & Electrical Supervisor, Seattle 

Plant, Ash Grove Cement

2921 August 31, 2009 Aaron Mott, Private Citizen

2922 September 04, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA)

2923 August 24, 2009 Brenton Kidder, Private Citizen

2924 September 26, 2009 Brian Good, Private Citizen

2925 August 12, 2009 Brian G. Finch, Private Citizen

2926 August 30, 2009 Bryan Pintok, Private Citizen

2927 August 05, 2009 Gail Cheeseman, Private Citizen

2928 September 10, 2009 Jim Schermbeck, Director, Downwinders At Risk

2929 September 04, 2009 Stephen Minick, Vice President, Governmental Affairs, Texas 

Association of Business

2930 August 26, 2009 Chris Barrett, Private Citizen

2931 August 26, 2009 Christ Hasser, Private Citizen

2932 August 25, 2009 Chris Hughes, Private Citizen

2933 September 01, 2009 Anonymous Public Comment

2934 August 24, 2009 Corey Younger, Private Citizen

2935 August 14, 2009 Alan Finch, Private Citizen

2936 August 25, 2009 Courtney Washburn, Private Citizen

2937 September 04, 2009 Neil J. Carman, Ph.D., Director, Clean Air Porgram, Lone Star 

Chapter of Sierra Club et al.

2938 August 27, 2009 Anonymous Public Comment

2939 August 28, 2009 Don and Dawn O'Grady, Private Citizen

2940 August 26, 2009 Denise Kemp, Private Citizen

2941 August 27, 2009 Donald R. and Ann Clark, Private Citizens

2942 August 25, 2009 Daniel Peters, Private Citizen

2943 August 17, 2009 Lisa De Golier, Private Citizen

2944 August 25, 2009 Logan A. Loening, Private Citizen

2945 August 25, 2009 Lynelle Lewis-Raymond, Private Citizen

2946 August 25, 2009 Margaret Schiff, Private Citizen

2947 August 12, 2009 Dan Shaffer, Dykman Electrical, Inc.

2948 August 31, 2009 Vicky Ho, Private Citizen

2949 August 24, 2009 William and Wanda Jennings, Private Citizen

2950 August 28, 2009 Ken Ware, Private Citizen

2951 August 27, 2009 Leland H. Page II, P.E., Private Citizen

2952 September 01, 2009 Dustin Scott, General Manager, Umatilla Ready-Mix, Inc.

2953 September 01, 2009 Kevin Bell, Clarke & Clarke Insurance
25

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2954 September 03, 2009 Tim and Jan Kerns, Kerns Rainbow Ranch, Inc.

2955 September 04, 2009 Ananda Lee Tan, U.S. Coordinator, Global Alliance for 

Incinerator Alternatives (GAIA)

2956 August 26, 2009 Maxine J. Murray, Private Citizen

2957 August 24, 2009 Paul J. Lyons, Private Citizen

2958 August 26, 2009 Rick L. Wallace, Private Citizen

2959 August 31, 2009 Elmer M. and Sheila M. Hill, Private Citizens

2960 August 26, 2009 Sherman W. Murray, Private Citizen

2961 September 02, 2009 Bob Groppo, Private Citizen

2962 September 02, 2009 Boris Degtyar, Private Citizen

2963 September 03, 2009 Bradley Walker, Private Citizen

2964 September 03, 2009 Kathleen Smith, Private Citizen

2965 September 03, 2009 A. Burr Tyler, Private Citizen

2966 September 04, 2009 Sandra R. Dickey, Private Citizen

2967 September 03, 2009 Cathy Trimble, Private Citizen

2968 September 02, 2009 David H. Jones, Private Citizen

2969 September 04, 2009 Mike Schaufler, State Representative, District 48, Oregon 

House of Representatives

2970 September 03, 2009 Chad Williams, Private Citizen

2971 September 03, 2009 Steve Bochenek, Private Citizen

2972 September 04, 2009 Denny Larson, Exec. Director, Global Community Monitor

2973 August 31, 2009 James Wells, District Sales Manager, Ash Grove Cement 

Company

2974 September 03, 2009 Kathryn Ballard, Private Citizen

2975 September 04, 2009 Diana Matley, Private Citizen

2976 September 03, 2009 Donnas Smith, Private Citizen

2977 September 01, 2009 D.T. Iddins, MD, Private Citizen

2978 September 01, 2009 Elwood Wirth and Family, Private Citizens

2979 September 02, 2009 Wade Christensen, Private Citizen

2980 September 03, 2009 Heather Ward and Family

2981 September 04, 2009 Linda K. Hughes, Private Citizen

2982 August 29, 2009 John Martin, Laborer/Physical Tester, Ash Grove Cement Plant

2983 September 03, 2009 Anonymous Public Comment

2984 August 28, 2009 Justin Hayes, Program Director, Idaho Conservation League

2985 September 03, 2009 Janet Hedley, Private Citizen

2986 September 02, 2009 Jim Wheeler, Private Citizen

2987 September 01, 2009 Joan Stempniak, Private Citizen

2988 September 03, 2009 Kyle Hancock, Private Citizen

2989 September 03, 2009 Laina Raveendran Greene, Private Citizen

2990 September 02, 2009 Lareen Jacobs, Private Citizen
26

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

2991 September 04, 2009 Leslie Fowler, Private Citizen

2992 September 04, 2009 Lethika Richter-Addo, Private Citizen

2993 September 04, 2009 Christopher Lish, Private Citizen

2994 September 03, 2009 Gregor Becker, Private Citizen

2995 September 02, 2009 Gregory Becker, Private Citizen

2996 August 24, 2009 Ryan Deckert, President, The Oregon Business Association 

(OBA)

2997 September 03, 2009 T.C. Johnston, Sr., Private Citizen

2998 August 14, 2009 Gary D. McCall, McCall Industrial Supply

2999 August 20, 2009 Walter L. Johnson, Private Citizen

3000 August 13, 2009 Warren Weatherspoon, Private Citizen

3001 August 25, 2009 Yvonne Shevnin, COO, Enfinittee, LLC

3002 September 04, 2009 Dr. J. O'Donnell, Private Citizen

3003 September 01, 2009 Julia Olson, Private Citizen

3004 September 03, 2009 Julie Gutierrez, Private Citizen

3005 September 04, 2009 Katherine D. Allen, Private Citizen

3006 September 01, 2009 Charlotte (no surname provided), Private Citizen

3007 September 03, 2009 Louise Pillai, Private Citizen

3008 September 03, 2009 Louise Pillai, Private Citizen

3009 August 24, 2009 Ryan Deckert, President, The Oregon Business Association 

(OBA)

3010 September 02, 2009 Lynn Metrulas, Private Citizen

3011 September 03, 2009 M. and T. Manickam, Private Citizen

3012 August 21, 2009 Bill Hubbell, General Manager, Wilco-Winfield LLC

3013 August 28, 2009 Evelyn M. Christensen, Private Citizen

3014 August 27, 2009 Anonymous Public Comment

3015 September 04, 2009 Margie Gong, , Private Citizen

3016 September 03, 2009 Diane Soffe, Private Citizen

3017 September 04, 2009 Rhoda Fry, Private Citizen

3018 September 01, 2009 Rhonda Givson, Retired Teacher, Private Citizen

3019 September 03, 2009 Mark Soffe, Private Citizen

3020 September 03, 2009 Marta Tingdale, RRT, TN, Private Citizen

3021 September 03, 2009 Mary Ann Mayer Redmond, Private Citizen

3022 September 04, 2009 Mary Harrison, Private Citizen

3023 September 04, 2009 Mary Peveto, Private Citizen

3024 August 26, 2009 Thomas Mumley, Assistant Executive Officer, San Francisco 

Bay Water Board

3025 September 03, 2009 Richard Lines, Private Citizen

3026 September 04, 2009 M. G. Bloom, Private Citizen

3027 September 03, 2009 Roxanne Christal, Private Citizen
27

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3028 September 03, 2009 Sam Pratt, Private Citizen

3029 September 02, 2009 Samantha Bornhorst, Private Citizen

3030 September 01, 2009 Sandra Breakfield, Private Citizen

3031 September 02, 2009 Martin Schiltz, Private Citizen

3032 September 03, 2009 Maureen Porter, Private Citizen

3033 September 03, 2009 Michele Westlaken, Private Citizen

3034 September 04, 2009 Michelle Craig, Private Citizen

3035 September 03, 2009 Nancy Johnstone, Private Citizen

3036 September 01, 2009 Sarah Castor, Private Citizen

3037 September 03, 2009 Sarah Laurie, Private Citizen

3038 September 02, 2009 Seth Cohen, Private Citizen

3039 September 04, 2009 Shannon Huges, Private Citizen

3040 September 04, 2009 Amy Parenti,, Private Citizen

3041 September 04, 2009 Jennifer Swearingen, Private Citizen

3042 September 03, 2009 Peeyush Jain, Private Citizen

3043 September 03, 2009 Philip Johnson, Private Citizen

3044 September 03, 2009 Allison Sunshine, Private Citizen

3045 September 04, 2009 Sheila Jones, Private Citizen

3046 September 03, 2009 Sue Blair, Private Citizen

3047 September 03, 2009 Susan Waskey, Private Citizen

3048 September 02, 2009 Susanne Endisch, Private Citizen

3049 September 03, 2009 Suzanne Baker, Private Citizen

3050 September 03, 2009 Terri Rimmer, Private Citizen

3051 September 04, 2009 Jeanne Schumacher, Private Citizen

3052 September 04, 2009 Arran E. Thomson, Private Citizen

3053 September 03, 2009 Vicki Oppenheim, Private Citizen

3054 September 02, 2009 Vinita Soin, Private Citizen

3055 September 04, 2009 Gerald Yeoumans, Private Citizen

3056 August 31, 2009 Gail Bower, Private Citizen

3057 August 24, 2009 George and Frances Alderson, Private Citizen

3058 August 27, 2009 Ginger Younger, Private Citizen

3059 August 25, 2009 Ignatius and Josephine Ding, Private Citizen

3060 August 26, 2009 James Robenolt and Mary Minow, Private Citizens

3061 August 20, 2009 Jenny Pompilio, M.D., MPH, Private Citizen

3062 August 24, 2009 Jerry Randolph, Private Citizen

3063 August 7, 2009 Jessica Shlager, Private Citizen

3064 August 28, 2009 James E. Finch, Private Citizen

3065 August 21, 2009 John Condon, Private Citizen

3066 August 19, 2009 Rodd and Rhea Bunch, Private Citizen
28

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3067 September 03, 2009 Robert R. Geddis, QEP, Private Citizen

3068 September 01, 2009 Glenn Foote, Eastern Oregon Service Company (EOSC)

3069 September 03, 2009 J. Jared Snyder, Assistant Commissioner, Office of Air 

Resources, Climate Change and Energy, New York State 

Department of Environmental Conservation

3070 September 02, 2009 Dawn Dawson, Secretary, Dawson Trucking, Inc.

3071 September 03, 2009 Vivian Zikmund, Private Citizen

3072 August 27, 2009 Jerri Wickert, Private Citizen

3073 August 05, 2009 J. Amberg, Private Citizen

3074 August 07, 2009 Jane S. Philipson, Private Citizen

3075 August 28, 2009 Kari Van Artsdalen, Private Citizen

3076 August 25, 2009 Kay Hummel, Private Citizen

3077 August 08, 2009 Kim Jelfs, Private Citizen

3078 September 01, 2009 Kathryn C. White, Private Citizen

3079 August 31, 2009 Larry D. and Maxine J. Cole, Private Citizens

3080 September 09, 2009 Congresswoman Eddie Bernice Johnson, Member of Congress 

3081 September 01, 2009 Patrick Flanagan, Private Citizen

3082 September 15, 2009 Anonymous Public Comment

3083 September 03, 2009 Bill Zikmund, Private Citizen

3084 August 29, 2009 Anonymous Public Comment

3085 August 24, 2009 Dick and Laura Parsons, Private Citizen

3086 August 25, 2009 Linda Olson, Private Citizen

3087 September 04, 2009 Anonymous Mass Comment Campaign sponsoring organization 

unknown (23)

3088 August 24, 2009 Anonymous Mass Comment Campaign sponsoring organization 

unknown (129)

3089 August 25, 2009 Anonymous Mass Comment Campaign sponsoring organization 

unknown (46)

3090 September 03, 2009 B. Sap, Private Citizen

3091 September 03, 2009 Gary Gable, Private Citizen

3092 September 03, 2009 William B. McNabb, President, McNabb Trucking

3093 September 03, 2009 Anita McKinney, Private Citizen

3094 September 03, 2009 Mr. and Mrs. W. Holoboff, Private Citizen

3095 September 03, 2009 Dale Smith, Private Citizen

3096 September 03, 2009 D. and B. Shumway, Private Citizen

3097 July 22, 2009 Maxine J. Murray, Private Citizen

3098 August 29, 2009 Anonymous Public Comment

3099 August 13, 2009 Michael Anderson, Private Citizen

3100 August 28, 2009 Michael Van Artsdalen, Private Citizen

3101 August 23, 2009 Michael Condon, Private Citizen
29

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3102 August 12, 2009 Mike G. Eiselein, Private Citizen

3103 September 01, 2009 Nancy Sanchez, Private Citizen

3104 September 01, 2009 Nicholas O'Neil, Private Citizen

3105 August 20, 2009 Nick Littlejohn, Private Citizen

3106 August 25, 2009 Anonymous Public Comment

3107 August 8, 2009 Phil Jelfs, Private Citizen

3108 August 25, 2009 Breanna Teintze, Private Citizen

3109 August 21, 2009 Barbara G. Sidway, Private Citizen

3110 August 12, 2009 R. Kaminsky, Private Citizen

3111 September 01, 2009 Reece M. Hrizuk, Private Citizen

3112 August 21, 2009 Anonymous Public Comment

3113 August 24, 2009 Richard Kuhnet, Private Citizen

3114 August 25, 2009 Anonymous Public Comment

3115 August 21, 2009 Rod F. Cook, Private Citizen

3116 August 20, 2009 Roger L. Weber, Private Citizen

3117 August 25, 2009 Rosemary Marks, Private Citizen

3118 August 24, 2009 Roy Heberger, Private Citizen

3119 September 03, 2009 J. McKinney, Private Citizen

3120 September 03, 2009 Ron and Janice Parsons, Private Citizen

3121 September 03, 2009 Janine R. Little, Private Citizen

3122 September 03, 2009 Wilma J. Rogers, Private Citizen

3123 September 03, 2009 State Representative Ron Maurer, Ed., D., House Republican 

Whip, District 3, Oregon House of Representatives

3124 September 03, 2009 William C. Parrish, Jr., Chief Executive Officer (CEO), Santa 

Clara County Medical Association (SCCMA)

3125 August 21, 2009 Ken Smyth, Private Citizen

3126 August 28, 2009 Kevin Harris, Private Citizen

3127 July 29, 2009 Kie and Cindy Hale, Private Citizen

3128 August 10, 2009 Amy L. Lansky, Private Citizen

3129 August 26, 2009 Sandra R. Dickey, Private Citizen

3130 August 5, 2009 Barbara Fukumoto, Private Citizen

3131 August 26, 2009 Cathy Helgerson, Private Citizen

3132 August 10, 2009 Teri Wiss, Private Citizen

3133 August 28, 2009 Tom Beverly, Private Citizen

3134 August 10, 2009 Marianne F. Tranter, Private Citizen

3135 August 11, 2009 Richard R. Tranter, Private Citizen

3136 August 31, 2009 Fred D. Blackham, Private Citizen

3137 September 14, 2009 Alvaro Linero, P.E., Program Administrator, State of Florida 

Department of Environmental Protection
30

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3138 September 04, 2009 Anne Hedges, Program Director, Montana Environmental 

Information Center (MEIC)

3139 September 03, 2009 Cecil Mark Benintendi, Private Citizen

3140 September 03, 2009 Diane Schrack, Private Citizen

3141 September 01, 2009 Baker County Board of Commissioners, Baker City, Baker 

County, Oregon

3142 September 08, 2009 Randall G. Gross, Jr., Director of Environmental and 

Regulatory Policy, Michigan Manufacturers Association 

(MMA)

3143 September 08, 2009 Jim Folsom, Jr., Lieutenant Governor, Alabama State House, 

State of Alabama

3144 September 08, 2009 Mark Murphy, VP, CPM Development Corporation

3145 September 09, 2009 Joan Howe, Private Citizen

3146 September 11, 2009 Donald. E. Morgan, Private Citizen

3147 September 11, 2009 Steve Robinson, President, Spokane Rock Products, Inc.

3148 September 10, 2009 Candy Howland, Owner, Candy's Corner Market

3149 September 14, 2009 P.J. Lier, Private Citizen

3150 September 15, 2009 B. Vanderwall, Private Citizen

3151dSeptember 15, 2009 Andrew T. O'Hare, Vice President, Regulatory Affairs, Portland 

Cement Association (PCA)

3152 August 24, 2009 John Woolley, President, Olympic Forest Coalition, (OFCO)

3153 September 15, 2009 Christopher I. West, Private Citizen

3154dSeptember 16, 2009 R. Latane Montague, Partner, Hogan and Hartson on behalf of 

Ted Kniesche, Vice President, Fulcrum Bioenergy, Inc.

3155 September 15, 2009 Representative Greg Walden, Second District, Oregon, U.S. 

House of Representatives

3156 September 03, 2009 Sharla Vaughan, Private Citizen

3157 July 28, 2009 Lori Finch, Private Citizen

3158 August 28, 2009 Heather Finch, Private Citizen

3159 August 14, 2009 Herbert L. Keyser, Private Citizen

3160 August 07, 2009 Allison Marks, Private Citizen

3161 September 04, 2009 Hazel Lambert, Private Citizen

3162 August 28, 2009 Mohsen Nazemi, P.E., Deputy Executive Officer, Engineering 

and Compliance, South Coast Air Quality Management District 

(SCAQMD)

3163 September 04, 2009 K. and J. Dyke, Private Citizen

3164 September 03, 2009 Anonymous public comment

3165 September 04, 2009 Alva R. Mascall, S. C. Mascall, and T. Orr

3166 September 03, 2009 Ed Hardt, President, Eastern Oregon Mining Association 

(EOMA)

3167 September 02, 2009 Elyse Kunz, Board of Directors, Community Advocates for 

Safe Emissions (CASE)
31

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3168 September 01, 2009 R. L. Moore, Private Citizen

3169 September 15, 2009 Lewis F. Gossett, President and Chief Executive Officer (CEO), 

South Carolina Manufacturers Alliance (SCMA)

3170 September 15, 2009 Jon Baggett, Director, Dorchester County Economic 

Development, Dorchester County, Maryland

3171 September 03, 2009 Comment submitted by State Senator Jason Allen, Majority 

Whip, 37th District, Michigan State Senate

3172 September 15, 2009 State Senator Kevin Engler, District 3, Missouri State Senate

3173 September 03, 2009 Carl Stiff, M.D., Baker County Commissioner, Baker County, 

Oregon

3174 September 08, 2009 D. (surname illegible), Private Citizen

3175 September 08, 2009 Tim Pope, Private Citizen

3176 September 08, 2009 Wade L. Boxberger, Private Citizen

3177 September 08, 2009 Richard D'Ewart, Private Citizen

3178 September 08, 2009 John R. McLean, Private Citizen

3179 September 08, 2009 Representative Bart Stupak, (MI-1) and Representative Charles 

W. Dent, (PA-15) Co-Chairs, Congressional Cement Caucus, 

Congress of the United States

3180 August 31, 2009 Kenneth W. Carlson, President, C and A Equipment Company

3181 September 08, 2009 Chris Combs, Private Citizen

3182 September 08, 2009 J.T. "JABO" Waggoner, Senate Minority Leader, District 16, 

Alabama State Senate

3183 September 08, 2009 Douglas L. Whitley, President and Chief Executive Officer 

(CEO), Illinois Chamber of Commerce

3184 September 08, 2009 Seth Hammett, Speaker, House of Representatives

3185 September 08, 2009 Representative Mike Hill, House of Representatives, Alabama 

State House

3186 September 08, 2009 Craig A. Dally, State Representative, 138th Legislative District, 

House of Representatives, Commonwealth of Pennsylvania

3187 September 08, 2009 Julie Harhart, State Representative, 183rd Legislative District, 

House of Representatives, Commonwealth of Pennsylvania

3188 September 08, 2009 Jari Askins, Lieutenant Governor, State of Oklahoma

3189 September 08, 2009 Ray Salva, State Representative, District 51, Missouri House of 

Representatives

3190 September 08, 2009 Cam Ward, House of Representatives, Alabama State House

3191 September 08, 2009 Joseph F. Brennan, State Representative, 133rd Legislative 

District, House of Representatives, Commonwealth of 

Pennsylvania

3192 September 08, 2009 Hank Erwin, State Senator 14th District, Alabama State Senate, 

Alabama State House

3193 September 08, 2009 Congressman John Shimkus, 19th District of Illinois, Congress 

of the United States, House of Representatives

3194 August 06, 2009 Eugene Stackle, Manager, Baker Economic Development
32

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3195 September 04, 2009 Howard L. Giberg, Counsel, Guida, Slavich and Flores on 

behalf of the Tile Council of North America, Inc. (TCNA)

3196 September 08, 2009 George H. Winner, Jr., Member of Senate, The Senate State of 

New York

3197 September 08, 2009 Tony Stamas, State Senator, 36th District, The Senate State of 

Michigan

3198 September 04, 2009 Neil D. Breslin, Member of Senate, New York State Senate

3199 September 08, 2009 Representative Jimmy Martin, House of Representatives, 

Alabama State House

3200 September 08, 2009 Patrick M. Browne, Senator 16th District, Commonwealth of 

Pennsylvania, Senate of Pennsylvania

3201 September 08, 2009 Doug Roberts, Jr., Director of Environmental and Energy 

Policy, Michigan Chamber of Commerce

3202 September 04, 2009 George W. Roy, Mayor, City of Calera

3203 September 04, 2009 Andy Neumann, State Representative for Alcona, Alpena, 

Crawford, Montmorency, Oscoda and Presque Isle Counties, 

Michigan House of Representatives

3204 September 02, 2009 Ed Hardt, President, Eastern Oregon Mining Association 

(EOMA)

3205 September 04, 2009 Roger Smitherman, President Pro Tempore, Alabama State 

Senate, Alabama State House

3206 September 04, 2009 Mayor Stanley J. Salva, City of Sugar Creek, Missouri

3207 September 04, 2009 Glen Zorn, Assistant Commissioner, State of Alabama 

Department of Agriculture and Industries

3208 August 24, 2009 Wyatt Pegg, President , Western Interlock, Inc.

3209 August 31, 2009 John C. Colbert, Vice President and General Manager, 

Automatic Wiber Vault Co., Inc.

3210 September 08, 2009 M. D'Ewart Logsdon, Private Citizen

3211 September 04, 2009 Mark Mullins, Private Citizen

3212 September 08, 2009 Norma Job, Private Citizen

3213 September 08, 2009 Elmer M. and Sheila M. Hill, Private Citizens

3214 September 08, 2009 Robert M. Hardy, Private Citizen

3215 September 08, 2009 Charles D. Carey, Private Citizen

3216 September 08, 2009 Robert Harris, Private Citizen

3217 September 08, 2009 Claude and Jane Treanor, Private Citizens

3218 September 08, 2009 Michael J. Hrizuk, Private Citizen

3219 September 04, 2009 Clifford T. Smith, Private Citizen

3220 September 04, 2009 Edward P. Stocks, Private Citizen

3221 September 04, 2009 Jeff Wiest, Private Citizen

3222 September 08, 2009 Tony DeFalco, Private Citizen

3223 September 05, 2009 Julia Chen, Private Citizen

3224 September 08, 2009 Dennis L. West, Private Citizen
33

Table 1-1. (continued)

Docket No. EPA-HQOAR-2002-0051 Date Received Commenter Name and Affiliation

3225 September 09, 2009 Phillip Teintze, Private Citizen

3226 September 13, 2009 Kerrie Utsumi, Private Citizen

3227 September 20, 2009 Panos Kougiouris, Private Citizen

3228 October 05, 2009 Sally and Wick Drummon, Private Citizens

3229 October 05, 2006 Craig Clapsaddle, Mechanical Systems, Inc.

Notes:

a. Request for extension of public comment period.

b. Duplicate copies of same comments entered in docket.

c. Comment is incomplete.

d. These items were submitted to the wrong docket.
34

2.0 Proposed Amendments to the Current NESHAP from Portland Cement 

Manufacturing Industry (05/06/09)

2.2 General

2.2.1 Support

Comment: More than 700 commenters supported the proposed amendments to the NESHAP for 

portland cement manufacturing. The commenters supported the proposal because it would reduce 

emissions of hazardous air pollutants (HAP), especially mercury, and reduce risks to health and 

protect the environment. Many of the commenters that supported the proposed amendments also 

stated that they did not support the use of subcategorization especially in the case of the mercury

emission standards.

Response: EPA acknowledges the commenters’ support. 

2.2.2 Oppose

Comment: More than 200 commenters stated that they opposed all or parts of the proposed 

amendments to the NESHAP for portland cement manufacturing. For example, many of the 

commenters opposed the proposed standards for mercury because naturally high mercury

concentrations in limestone would mean that a Portland cement plant in their community would 

be unable to comply with the emission limit for mercury even after installing control devices. 

These commenters pointed out that the plant had reached an agreement with the State to reduce 

mercury emissions by 75 percent by installing an activated carbon injection system and to use 

other means to reduce mercury emissions by 85 percent by the year 2012. These commenters 

stated that closure of the plant would have negative impacts on the community as a result of job 

losses and lost income for individuals and municipalities and would result in the importation of 

cement from countries where there are fewer environmental controls. Many of these commenters 

requested that, in order to avoid these negative impacts, EPA create a subcategory for cement 

plants that must use limestone that contains naturally high mercury concentrations and that EPA 

require that plants in this subcategory apply air pollution control technologies that represent 

maximum achievable control technology (MACT). 

Many commenters also opposed the pollutant-by-pollutant approach EPA used to set MACT 

floor standards due to the likely negative impacts on the cement industry. 

Response: As explained in the preamble to the final rule, EPA has choosing not to create a 

subcategory for the two plants with exceptionally high mercury emissions due to limestone 

mercury levels. EPA also explains in the preamble why setting floors HAP-by-HAP is both 

permissible and better promotes statutory objectives than setting floors based on performance of 

entire facilities.
35

2.3 Overall Approach to Setting MACT Floor Limits

2.3.1 Variability and Adequacy of Data

Many comments were received on various aspects of the data and the adequacy of the data used 

by EPA in setting MACT floor limits and on the statistical methods EPA used to estimate 

variability in the data for purposes of setting MACT floor limits.

Adequacy of data

Comment: On the issue of the adequacy of the data used to develop the MACT floor limits, 

many commenters (2832, 2841, 2844, 2845, 2859, 2863, 2864, 2874, 2889, 2900, 2901, 2914, 

and 2918) stated that EPA should have collected data from a larger portion of the kiln 

population. Commenters 2844 and 2845 offered assistance in improving the data supporting the 

standards and the subcategorization. Commenter 2889 suggested that EPA should either initiate 

requests for additional industry-specific data or determine if relevant control technology and 

emissions data are available in other industrial categories. Commenter 2844 stated that for EPA 

to devise the variability methodologies consistent with Brick MACT and other relevant case and 

statutory law, EPA can exercise its discretion to seek appropriate data from regulated entities and 

other stakeholders and make discretionary methodological determinations of how best to 

estimate the necessary information, so long as EPA’s approach is fact-based and reasonable. 

On the question of the adequacy of the data used to set MACT floors, commenter 2832 stated 

that the use of as few as two data points for the creation of the MACT standard for existing 

sources does not reflect a statistically significant number and should not be used for the 

establishment of a standard.

Many commenters (2841, 2844, 2846, 2858, 2863, 2874, 2915, and 2929) stated that EPA’s 

limits were based on limited testing and/or short-term operations. Short-term data may not 

capture variability that occurs in a facility, and since the industry is expected to be in compliance 

all of the time, not simply most of the time, it is critical to account for normal variability. 

Commenter 2844 argued that short-term testing is insufficient to capture emissions variability

associated with nontechnological operational factors.

Response: As described in more detail in the preamble, EPA has made every effort to generate 

data for this rule. For mercury, EPA compelled plants in the industry to gather 30 days of 

sampling data by means of section 114 requests. EPA has repeatedly requested, indeed implored,

the industry to provide longer-term sampling data to support their assertions that mercury input 

variability is greater, but industry largely chose not to do so. Cf. Association of Pacific Fisheries 

v. EPA, 617 F. 2d 794, 817 (9th Cir. 1980) (burden on industry to provide data in its possession).

EPA also adjusted its data base where commenters provided reliable information about mercury

content of inputs not reflected in the EPA-compelled sampling effort. See in particular comment 

2845 at pp. 32-33. For THC, EPA has compiled data from best performing sources comprising 

years of operating data, measured continuously. (Industry participated constructively in 

supplementing the database used at proposal, although delays in providing certain supplemental 

information and significant methodological issues relating to that supplemented information led 

to EPA’s decision not to use those additional data in developing the THC standard. In any case, 
36

EPA views the late-submitted information as corroborating the promulgated standard, as 

explained in the preamble to the final rule.) For HCl, EPA again used its section 114 authority to

gather further data on emission levels. For PM, EPA also supplemented its data base at proposal 

(including adding data supplied by LaFarge North America Inc. which better characterized the 

performance of two of its kilns). EPA further applied well-recognized statistical methodologies 

to the mercury and PM data to further project sources’ variability. EPA believes that these efforts 

result in floor determinations that reasonably estimate performance over time of best performing 

sources.

Furthermore, in response to commenter 2844 and others, in no instance is EPA relying solely on 

stack testing to assess sources’ performance. The mercury, PM and HCl standards utilize the 99th

percentile UPL formula to further assess performance and variability. The mercury data comes 

from total facility input testing over 30-days, not from individual stack tests. EPA further 

adjusted these data to account for best performers’ changes in mercury inputs outside the 30-day

sampling period (where properly documented), and further adjusted the estimated intra-quarry

mercury variability for the pool of best performers based on the reasonably-estimated long-term 

intra-quarry variability of the two best performing sources. This yielded a floor standard of 55 

lb/MMT clinker. At least one industry commenter (commenter 2830, Essroc Cement) stated that 

proper use of statistics to estimate variability for mercury should result in a standard between 43 

and 50 lb/MMT clinker (slightly lower than the standard EPA adopted, am indication to EPA 

that it is adequately accounting for variability of inputs and ultimate performance). 1 The THC 

standard relies on hundreds of observations per facility, obtained by continuous emission 

monitoring, not by individual stack tests. All of the standards use a pooled variability developed 

from the pool of best performing sources. This comment is thus factually mistaken.

Comment: Commenters 2844 and 2846 stated that Brick MACT held that EPA must base floors 

on achieved emissions control rather than control technology choices and this may require 

additional data from stakeholders. The commenter notes that floors now must address the impact 

of testing variability, technological variability and nontechnological factors if they impact 

emission levels achieved in practice. Non-intentional factors must also be taken into 

consideration, such as a technology that dramatically lowers its emissions of a particular HAP 

but at the same time increases its emissions of other HAPs or other air pollutants. EPA must take 

those factors into account when setting the floor and must devise a reasonable way to address 

such factors in its methodology. 

Response: EPA has accounted for testing variability, technological variability (i.e. variability in 

control device performance), and variable HAP content of raw materials and fuels utilized by

best performing sources in developing each of the standards. However, as explained in the 

preamble to the final rule, there is no instance where technology which controls one HAP 

increases emissions of another. Put another way, means of control are available to the industry

which are mutually compatible, not mutually exclusive.

 

1 At proposal, EPA also presented long term mercury data from an Essroc kilns showing relative standard 

deviations similar to the range of the relative standard deviations of the best performing kilns, based on 30-days of 

data, again suggesting that EPA had properly assessed variability of mercury inputs. 74 FR at 21143.
37

Comment: One commenter (2844) stated that EPA should use the emissions data for the large 

number of kilns in the docket to get the most accurate perspective on emissions and control 

needed.

Response: See previous response

EPA’s use of statistical methodologies in assessing variability

Comment: On the EPA’s consideration of variability in setting the MACT floor limits, one 

commenter (2845) provided a detailed discussion of the statistical methods used by EPA to 

derive the 99th percentile values which EPA developed the proposed MACT floors for mercury, 

HCl, THC, and particulate matter (PM). The commenter stated that the EPA should use the upper 

tolerance limit (UTL) method to account for variability where data is limited and use actual data 

in large data sets. Where there is very limited data, which is the case for HCl, it is not possible to 

perform any statistical analysis or extrapolate a 99th percentile; therefore, it is not appropriate to 

use existing data to establish a MACT floor for HCl using even the upper tolerance limit (UTL) 

methodology. This commenter also provided an extensive and detailed analysis of EPA’s 

analysis and data as well as an alternative analysis and MACT floors using different statistical 

methods and updates to EPA’s data sets.

Commenter 2832 supported EPA’s acknowledgement and recognition that data variability is a 

statistical issue that is required to be taken into account in setting a MACT floor. EPA should 

explain its selection of the Upper Prediction Limit (UPL) statistical approach and how that 

approach was applied to the data. 

Commenter 2864 agreed with EPA’s use of the 99th percentile for the MACT floor sources, 

stating that its use accounts for emissions variability. However, the commenter disagreed with 

the approach used to estimate the upper 99th percentile. The UPL statistical method does not 

actually generate the 99th percentile for the data sets in the MACT floor in the Proposal. Instead, 

it generates a probability for a single value that is possible in the future, which is not a 99th

percentile. The commenter stated that EPA should use an UTL to estimate the 99th percentile for 

small data sets and an actual 99th percentile where large data sets are available.

One commenter (2829) disagreed with EPA’s calculation of the MACT standard emission limits. 

The commenter stated that to account for variability, EPA should first establish standards that are

the actual average emission rates of the 12 percent of existing sources, and then use longer 

averaging times (perhaps 60 or 90 day averages) to allow for short term variability and spikes in 

emissions.

Response: EPA’s legal obligation in establishing MACT floors is to reasonably estimate the 

average performance achieved by the best performing 12 percent of best performing sources, or 

for new sources, the performance of the best controlled similar source. Although acknowledging 

that variability in best performing sources’ performance exists, commenter 2829 nonetheless 

maintained that EPA is compelled to select the arithmetic mean or median of the best performers 

and adjust for variability by taking expressing those values in longer averaging periods. EPA 

disagrees that it must establish floors based on the numerical average (or median). Caselaw, 

much of it cited in comments 2844 and 2845, as well as EPA in the preamble to the proposed and 
38

final rule, as well as at 70 FR at 59437, indicates that variability is to be accounted for by EPA in 

establishing MACT floors. This is because sources must comply at all times, so that their overall 

performance must be assessed. See, e.g. Mossville v. EPA, 370 F. 3d at 1242 (EPA properly 

used a highest data point to estimate best performing source’s performance, since this was part of 

its documented variability). Caselaw likewise indicates that EPA, in determining MACT floors,

can make reasonable estimates of sources’ performance, including estimates of sources’ 

variability. Cement Kiln Recycling Coalition v. EPA, 255 F. 3d at 862; Sierra Club v. EPAu, 167 

F. 3d at 661.

The statute does not speak to the issue of permissible averaging times in constructing standards, 

so it may be that in factually appropriate cases, a choice of averaging time to account for best 

performing sources’ variability could be legitimate. However, automatic (i.e., a priori) 

determinations to adopt long-term averages for any type of data set regardless of circumstances 

of sources’ performance and robustness of the data set would go too far. In addition, if the 

commenter is suggesting that EPA simply average short-term test results and then hope to 

account for variability by assigning a longer averaging period, EPA rejects such a methodology 

as both qualitative and arbitrary – it could easily result in estimates of performance that are either 

overly stringent or lax due to the rough estimate of variability underlying the methodology. It is 

better to more accurately assess sources’ initial performance (for example, as with the mercury

standard in this rule where EPA changed its baseline for best performing plants based on 

information about materials these sources process even though they did not do so in the 30-day

sampling regime), and to use statistical methodologies to account for the variability reflected in 

the resulting data set. 

Other factors that contribute to variability

Comment: Many commenters stated that varying levels of HAP in inputs contribute more to kiln 

emissions variability than variations in at-the-stack control performance, and that EPA should 

take these factors take into account when setting the MACT floor limits.

Commenters 2830, 2836, 2840, 2844, 2845, 2863, and 2929 stated that the chemical composition 

of inputs into the cement manufacturing process is highly variable and EPA’s consideration of 

this variability and its effect on emissions will dictate whether the final regulations will result in 

workable emission standards or standards that could adversely impact the portland cement 

industry, for example, by forcing the shutdown of domestic cement production capacity in the 

US, thereby inhibiting economic development in the US. The commenters stated that the 

limestone quarry is intrinsically linked to the cement manufacturing facility and is the main 

reason for the cement plant’s location. A typical plant will process more than a million tons and a 

half of material annually. Limestone represents approximately 70-80 percent of this volume. A 

cement plant will not be constructed unless there is a sufficient quantity and quality of limestone 

to last 50-100 years. 

Commenters 2844, 2845, and 2915 stated that the trace chemical composition of the fuels which 

come in direct contact with the raw feed materials include coal, petroleum coke and alternative 

fuels that include tires and industrial solvents. The variability of trace compounds in the 

conventional and alternative fuels may vary widely. The concentration of trace compounds 

present in the cement and other plant emissions may be highly variable, reflecting changes in the 
39

chemistry of conventional fuels and raw materials and their alternatives. EPA’s consideration of 

this variability will dictate whether the final regulations will result in workable emission 

standards or standards that could adversely impact the portland cement industry by forcing the 

shutdown of domestic cement production capacity in the United States, inhibiting economic 

development in the United States.

Commenter 2874 stated that EPA should revise the MACT floor for mercury by more 

comprehensively accounting for actual and reasonably foreseeable variability in the operations 

and delay promulgation of the THC emission standard until data has been gathered that will 

appropriately account for variability.

Commenters 2844, 2845, 2846, 2915, and 2929 stated that EPA should consider process 

variability and its effect on emissions. A single cement kiln produces various products 

throughout the year and may use different raw materials and fuels. Each product, raw material, 

and fuel results in different emission profiles from a kiln.

Response: As discussed in the preambles to both proposed and final rules, as well as other 

comment responses, EPA is aware that input (raw material and fuel) variability is the 

predominant contributor to both mercury and THC emissions, as well as their variability. EPA 

explains there at length how it accounts for these varying levels in inputs. EPA particularly 

emphasizes the pooled intra-quarry variability estimates for mercury as well as adjustments in 

particular sources’ average performance, plus use of the UPL 99th percentile statistic as means by 

which short-term and long-term variability are accounted for in the mercury standard. EPA has 

also carefully assessed the role of input variability in constructing the HCl and PM standards, 

although for these standards different factors (variability in analytic detection and control device 

variability) played the predominant role in assessing sources’ performance over time. 

Other factors that contribute to variability

Comment: One commenter (2844) stated that the terms in §112(d)(3) permit EPA to address the 

unique factors that affect emissions control achieved by sources. Such factors, even when not 

relevant to determining the actual emissions control of a particular HAP achieved by a source, 

may be relevant to determining whether a source that demonstrates low achieved emission levels 

is to be considered a best performing source for the purpose of setting a floor. The commenter 

stated that EPA may define best performers as the lowest emitters as long as EPA’s approach is 

reasonable in light of all relevant factual and data circumstances and so long as EPA reasonably

applies variability that impacts the lowest reported emissions in order to accurately estimate the 

level of control actually achieved by the best performing sources.

Commenter 2844 stated that a lawful floor setting methodology must estimate relevant emissions 

variability resulting from nontechnological factors. EPA has the discretion under §112 to devise 

methodologies for estimating variability that impacts emissions control. Variability in emissions 

results from test-related variability, technology-related variability, and nontechnological-related 

variability. The commenter provided discussion and examples. To be consistent with Brick 

MACT, EPA must address all the factors that impact variability of emissions, especially not 

ignoring nontechnological factors.
40

Response: EPA is not ignoring nontechnological factors in assessing variability. Indeed, for 

mercury, there are essentially no other factors to consider since the industry has not installed 

technological controls to reduce mercury emissions (hence EPA’s mass balance approach based 

on sampling of mercury levels in all kiln inputs as a means of assessing emission levels and 

overall performance). EPA agrees that determining which performers are best requires 

consideration of sources’ performance over time. See 72 FR at 54877 (Sept. 27, 2007).

Comment: Commenters 2845 and 2846 stated that EPA should not rely solely on short-term 

data from similar sources and ignore the variability and long term impact of the proposed 

emission rates. In EPA’s proposed rule to set a NESHAP for mercury at coal-fired electric 

utilities, the agency identified a number of factors that contribute to variability in emission test 

data. The commenter suggests that these factors should be considered in this rulemaking, and for 

cement kilns, the influence of raw materials should also be considered.

Response: In no instance is EPA relying exclusively on short-term data in establishing floors 

and standards. EPA has carefully considered the specific comments as to why mercury levels in 

inputs to the best performing sources could vary beyond the levels in the data base and made 

appropriate adjustments as a result. Use of the UPL statistic further accounts for this variability

(both from non-technological and technological factors), as explained in the preamble to the final 

rule.

2.3.2 Pollutant-by-Pollutant MACT Floors

CAA intent

Comment: Many commenters (2830, 2832, 2836, 2841, 2844, 2845, 2858, 2859, 2863, 2864, 

2874, 2890, 2908, 2910, 2914, 2915, 2916, and 2917) stated that setting MACT floors on a 

pollutant-by-pollutant basis violates the law and results in MACT floors that bear no relation to 

emission limits that are being achieved at the best performing existing sources. According to 

commenters, this method violates the plain language and intent of §112(d) of the Clean Air Act 

(CAA) and its effect is a MACT floor that reflects a standard that no one plant in existence 

currently achieves. The CAA requires a two-step process to set a MACT standard: first, EPA 

identifies a MACT floor for each pollutant and source category based on emission limitations 

that have already been achieved by the best-performing 12 percent of existing sources (Brick 

MACT, 479 F.3d at 877; Northeast Maryland Waste Disposal Auth. v. EPA, 358 F.3d 936, 954, 

D.C. Cir. 2004, and Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855, 866, D.C. Cir. 

2001). Then the CAA requires EPA to determine whether stricter standards—beyond the floor 

limits—are achievable, taking into account cost and feasibility factors.

Commenters 2832, 2841, 2844, 2845, 2846, 2910, 2914, 2915, and 2916 stated that §112(d)’s 

use of the terms best-performing and existing clearly means that sources in a category or 

subcategory that are used to set the MACT floor are to be real, not theoretical or hypothetical, 

sources (42 U.S.C. §7412(d), 2006 and Northeast Maryland Waste Disposal Authority, 358 F.3d 

at 954). The phrase achieved in practice can only mean that Congress intended actual sources, 

performing under real-life conditions, to be the benchmark for determining the MACT floors. 

Furthermore, the language of the statute does not speak in terms of the best-performing source or 

sources for each listed pollutant or group of pollutants (42 U.S.C. §7412(d)). Rather, the focus is 
41

on the best existing source or sources for all pollutants, and what these sources truly can achieve 

on an overall basis. EPA’s pollutant-by-pollutant methodology is also at odds with the legislative 

history underlying §112(d) (S. Rep. No. 228, 101st Cong., 1st Sess. 169, 1989). 

According to the commenters, the focus on overall performance is not surprising because in the 

1990 CAA Amendments Congress abandoned §112’s previous focus on individual pollutant 

standards, and adopted the technology-based multi-pollutant approach to regulating toxics in use 

under the Clean Water Act (CWA). See S. Rep. No. 228, 101st Cong., 1st Sess. 133-34 (1989). 

Thus, if one source can achieve a firm degree of control for one pollutant but not for another, 

there may be no justification for including it in the set of sources from which the floor is 

calculated (Tanners’ Council of America v. Train, 540 F.2d 1188, 1193 (4th Cir. 1976) deeming 

CWA effluent limitations guidelines not achievable where plants in EPA’s database were 

capable of meeting the limitations for some, but not all, of the pollutant parameters).

Several of these commenters provided a table (the result of an industry survey) listing EPA floor 

units and the ability or inability of cement plants to comply with the proposed existing source 

MACT limits for mercury, THC, HCl and PM. 

Several commenters (2845, 2910) stated that EPA’s previous use of a pollutant-by-pollutant 

analysis was based on authorities not applicable to the CAA. EPA previously used a pollutantby-pollutant methodology to set MACT floors in the context of the proposed NESHAP for 

Hazardous Waste Combustors, 69 FR 21198 (Apr. 20, 2004) [hereinafter Hazardous Waste 

NESHAP.] Several parties submitted public comments questioning EPA’s approach and pointing 

to the fact that EPA had failed to cite a single existing source which met the various MACT floor 

standards. See EPA’s Response to Comments on April 20, 2004 HWC MACT Proposed Rule, 

Volume 1: MACT Issues, 126 (Oct. 2008). In response, EPA attempted to defend its practice of 

establishing pollutant-by-pollutant MACT standards by citing Chemical Mfr. Ass’n. v EPA, 870 

F.2d 177, 239 (1989), clarified 885 F.2d 253, 264 (5th Cir. 1989), cert. denied, 495 U.S. 910, 

(1990), a case where the court held that, under the CWA, best available technology (BAT) 

referred to the single best-performing plant on a pollutant-by-pollutant basis.

According to commenters 2845 and 2910, EPA’s reliance on Chemical Mfr. Ass’n is misplaced 

as the CAA’s procedure regarding the selection of MACT technologies differs on a textual basis 

from the CWA’s procedure for identifying best available technology. Under the CWA, BAT 

standards are to be set based on the best practicable control technology currently available. 

33 U.S.C. §1311(b)(1)(A)(i)(2006). This has led to pollutant-by-pollutant determinations. The 

CAA more narrowly limits the basis for MACT designation to what has been achieved at 

existing sources, not what could be hypothetically achievable on a per-pollutant basis.

One commenter (2890) stated that EPA appears to be forgetting that the floor is only the first 

step in the process. Once EPA has established a floor based on physical sources, it is directed to 

go back and look at options beyond the floor. Those beyond the floor options would include the 

best control for each pollutant on every source. By correcting the floor approach, the EPA would 

also correct the issue identified by Judge Williams in his concurring opinion to the Brick vacatur, 

where a floor that is designed to represent what has been achieved is more stringent than what 

would be deemed achievable under a MACT.
42

Response: See preamble for response

Impacts of pollutant-by-pollutant approach

Comment: Several commenters (2831, 2844, 2845, and 2874) stated that in evaluating the 

economic cost of achieving emission reductions, looking at one plant’s emission control of only

one pollutant to the exclusion of all other emission controls produces a disjointed view of cost 

implications and compliance feasibility. While an individual MACT floor for one pollutant 

might not appear cost-prohibitive, when combined with all of the other MACT floors for other 

pollutants, the total cost implications could become especially onerous. While the CAA was 

authored with the intent of reducing air pollution, Congress did not intend to disrupt the 

productive capacity of the United States through the promulgation of economically unachievable 

standards. 42 U.S.C. §7401(b)(1)(2006). By setting MACT floors individually and ignoring the 

collective cost implications of the entire NESHAP, EPA would effectively disregard the CAA’s 

requirement that air pollution control be advanced while promoting the nation’s productive 

capacity. Id.

Response: See preamble for response

Comment: Several commenters (2845, 2889, and 2890) stated that EPA’s argument that EPA 

believes that because all our standards are not technically interdependent (i.e., implementation 

of one emission control technology does not prevent the source from implementing another 

control technology), the fact that sources are not achieving all the standards simultaneously does 

not indicate a flaw in the methodology is not valid. Commenter 2845 cites the example of 

activated carbon injection to reduce mercury from hazardous waste combustion, which has been 

observed to increase the emissions of dioxin/furans, calling into question EPA’s legal 

justification that control requirements for one pollutant do not impact another. Commenter 2889 

notes that the interaction between unit characteristics and control capabilities must be taken into 

account. Although there is no one kiln or no small number of kilns that simultaneously define the 

MACT floors for mercury, total hydrocarbons, hydrogen chloride, and particulate matter, all 

existing kilns will have to achieve all four requirements despite that fact that no single existing 

kiln achieves these requirements. 

Response: Although the commenter cited the example of activated carbon increasing dioxin 

emissions they provided no data to substantiate this claim. A thorough review of one of the 

references cited indicated there was no mention of dioxins or activated carbon injection. The 

other reference cited, which was not provided with comments, seems to imply that dioxin 

emissions increase relative to dioxin inputs if activated carbon is used. First, there is not 

sufficient information provided to determine the accuracy of this claim. The reference authors 

cited in the text did not match the information in the footnote, so we cannot ascertain if the 

correct reference was cited. Second, the statement said dioxins increased relative to dioxin 

inputs, and did not indicate if the dioxin emissions from the stack increased. So this information 

does not substantiate the claim that ACI increases dioxin emissions at the stack. Even assuming 

that dioxin emissions at the stack did increase, there are other factors that could influence dioxin 

emissions. For example, the temperature at the inlet of the control device has been determined to 

be a critical factor in formation of dioxins in these types of processes. In fact, proper control of 

temperature is the preferred method used to control dioxin emissions for this source category, 
43

and is part of the emissions standard (see 63.1343 (b)(3)(ii) and (c)(3)(ii)). Given the lack of 

information provided with this comment, and the errors noted, we do not believe that 

commenters have provided information that actually supports their statement. We also note that 

activated carbon injection is currently used to reduce emissions of dioxins from municipal solid 

waste incinerators.

The commenters have likewise provided no information to demonstrate that a facility cannot 

simultaneously control PM, HCl, THC, and mercury. For example, several cement kilns 

simultaneously control NOx, SO2 (which also reduced HCl), and PM using a fabric filter 

followed by a wet scrubber. Two older wet kilns controlled THC using activated carbon injection 

followed by a PM control. A new preheater precalciner kiln had PM (fabric filter), SO2 (wet 

scrubber) and THC (regenerative thermal oxidizer) controls in series. We also note that in the 

utility industry, simultaneous control of NOx, SO2, and PM are accomplished using selective 

catalytic reduction and wet scrubber controls in series. Municipal waste combustors 

simultaneously control dioxins and mercury using activated carbon injection, acid gases using 

spray dryers, and PM using fabric filters or electrostatic precipitator. In the specific case of 

cement kilns, we assume that a source needing to control all four pollutants would use a primary

PM control (mainly to capture valuable producer or raw materials that are emitted from the kiln), 

activated carbon injection followed by a polishing fabric filter (which would capture additional 

PM, remove the mercury, and remove the THC (or organic HAP if the alternative standard is 

used)) and a wet scrubber for HCl control. We costed this configuration for many kilns in our 

cost estimates for the rule. (See Regulatory Impact Analysis: Amendments to the NESHAP and 

NSPS for the Portland Cement Manufacturing Industry, Final Report, August 2010.) Depending 

on the uncontrolled levels of the pollutants, it may be very possible for many facilities to 

combine activated carbon injection and alkaline sorbent injection downstream of the primary PM 

control followed by a polishing fabric filter and control all four pollutants, PM HCl, THC, and 

mercury. Based on these facts, we see no technical impediment to simultaneously meeting all 

four emission standards in the NESHAP.

Subcategory for each HAP

Comment: One commenter (2890) asked EPA to clarify the statement on page 21145 of the 

proposal preamble that EPA, may create a subcategory applicable to a single HAP, rather than a 

source category, if the facts warrant (so that, for example, a subcategory for kilns emitting 

mercury, but a single category for kilns emitting HCl, is legally permissible with a proper factual 

basis). The commenter took this to mean that EPA is creating a subcategory for a single HAP.

Response: It is legally permissible to create HAP-specific subcategories, for example, where a 

difference in size, type or class of facility only affects emissions of one HAP but not others, 

although EPA is not doing so in this rule. See fuller discussion where EPA discusses whether to 

subcategorize on the basis of quarry limestone mercury levels. If EPA had chosen to do so, the 

subcategory would have contained two sources and would apply to emissions of mercury only.

2.3.3 Lowest Emitters Versus Best Performers

Comment: One commenter (2834) stated that the Brick MACT ruling of the D.C. Circuit Court 

reinforces earlier holdings in National Lime Association vs. EPA. The court again held that 
44

floors are to be based on the emission level actually achieved by the best performers (those with 

lowest emission levels) not the emission level achievable by all sources.

Response: See preamble for response

Comment: Many commenters (2841, 2844, 2845, 2846, 2858, and 2914) stated that EPA 

established its proposed floors equating best performing sources with those that have the lowest 

emissions for particular HAPs even though there are other ways to measure performance and, in 

some cases other methodologies may comply with the statute where the "lowest emitter" 

approach does not. Commenter 2845 noted that equating best performer with lowest emitter 

contravenes a Congressional directive that in developing MACT standards, EPA cannot require 

substitution of raw materials in mineral processing industries, such as cement manufacturing. 

The Joint Explanatory Statement of the Committee of Conference for the 1990 CAA 

Amendments stated: For categories and subcategories of sources of [HAPs] engaged in mining,

extraction, beneficiation, and processing of nonferrous ores, concentrates, minerals, metals, and 

related in-process materials, the Administrator shall not consider the substitution of, or other 

changes in, metal- or mineral- bearing raw materials that are used as feedstocks or material 

inputs . . . in setting emission standards, work practice standards, operating standards or other 

prohibitions or requirements or limitations under this section for such categories and 

subcategories. H.R. Rep. No. 101-952, at 339 (1990), quoted from Sierra Club v. EPA, 353 F.3d 

976, 988 (D.C. Cir. 2004). According to the commenters, enormous amounts of limestone are fed 

into a kiln to manufacture clinker, and it is cost-prohibitive to import limestone from further 

away. If the plant’s quarry contains limestone with high concentrations of mercury or high 

concentrations of organics, the kilns will emit more mercury or THC and potentially more 

organic HAPs. Because limestone with high mercury or organic emissions will result in higher 

HAP emissions, and it is not cost-effective to import limestone from far away, equating the 

lowest emitters with the best performing sources makes no sense in the context of cement 

facilities. It also would be squarely in opposition to the Joint Explanatory Statement.

Response: See response in preamble

Comment: Commenter 2844 stated that EPA could interpret §112(d)(3) as Brick MACT appears 

to do, as one unitary concept meaning sources with the lowest emission levels, or EPA can 

interpret it as a more complex concept that the EPA may determine the emission control (using 

any of the various definitions in the CAA) that sources have achieved in practice (as estimated 

by reasonably predictive variability factors) and rank them according to their relative emissions 

levels (i.e., a quantitative measure of achievement). Having done so, the Agency can then 

evaluate each of the lowest emitters in terms of whether they meet the Agency’s criteria for best 

controlled similar source. With regard to best controlled, EPA may evaluate this from a purely 

quantitative angle (lowest emissions) or from more qualitative aspects (reduction efficiency, 

environmental and health (or cross-media) impacts, cost-effectiveness of reductions achieved, 

impacts on other HAP or pollutant emissions, and so on.

Commenter 2845 provided several examples of court MACT decisions endorsing a technology 

approach to setting the standards, in which EPA selected the best performing sources based on 

the relative performance of air pollution control technology.
45

Commenter 2844 stated that EPA also has the discretion to define best performers as sources 

other than those with the lowest achieved emission levels. In the current proposal, the many

difficulties associated with evaluating the impact of HAP content in the raw material inputs to 

mercury emission control and other factors could support a decision by the agency to establish a 

standard based on efficiency (i.e., a percent reduction standard) if not for the source category as 

a whole, then such a standard might be established for a particular subcategory as relevant, or as 

an alternative compliance strategy. EPA’s discretion is sufficiently broad to encompass many

reasonable decisions identifying and estimating the emission control of best performing sources 

on bases other than lowest emissions data, assuming the floor for the standard is based on a 

reasonable methodology estimating the percent reduction achieved in practice by the best 

performing sources under the reasonably foreseeable worst operating conditions.

Commenter 2844 stated that before EPA can determine a floor, EPA must define the following 

terms in regard to the selection of a best performer for new sources: Emission control; Achieved 

in practice; Best controlled; and Similar source.

To set the floor for existing sources, the commenter stated that EPA should define the following 

terms: Average emission limitation; Achieved; and Best performing.

Response: See response in preamble to final rule.

Comment: Commenters 2832, 2846, and 2890 stated that rather than selecting sources with the 

lowest emissions for particular HAP as best performing sources, EPA could use the relative 

performance of air pollution control technology to select the best performing sources, applying 

the best reasonable method for determining best-performers, which does not necessarily have to 

equate to lowest emissions. 

Response: See response in preamble to final rule.

Comment: One commenter (2859) stated that EPA is making an unrealistic conclusion that best 

performing is equivalent to lowest emitting when applied to the Portland Cement NESHAP. In 

cement manufacturing, lowest emitting may be strictly related to a cement plant located adjacent 

to a source of limestone that has the lowest level of contaminants. The goal of the NESHAP is to 

reduce emissions of HAPs to the lowest possible level using the best technology. There are 

several examples in this rulemaking where the lowest emitting sources are not the most modern 

cement manufacturing technologies or utilizing the most modern pollution control measures. 

Conversely, some of the highest emitters are the most modern cement manufacturing 

technologies that employ the most modern pollution control measures. 

Response: The statement (without supporting citation) that “the goal of NESHAP is to reduce 

emissions of HAPs to the lowest possible level using the best technology” again ignores the 

contribution of raw material and fuel inputs.

Comment: One commenter (2832) stated that §112 did not define best performing major sources 

as those that emit the least HAP or HAPs. Unless a source is the lowest emitting for all HAPs of 

concern to EPA for a given industry, best performing cannot be defined as lowest emitting.
46

Response: EPA believes that selecting as best performers those with the lowest emissions of the 

HAP at issue is a reasonable and permissible approach for this rule.

Comment: One commenter (2844) stated that EPA has not taken the necessary steps to evaluate 

or validate whether its methodology in fact accurately estimates emissions control achieved in 

real world circumstances at sources.

Response: EPA disagrees strongly with this comment. Data for mercury and THC is long-term.

EPA has adjusted underlying data further where commenters provided reasonable quantitated 

information.

Comment: One commenter (2889) stated that EPA should avoid using outliers when 

determining the MACT floor. The sources should have process and raw material characteristics 

that are reasonably representative of the population of sources in the industrial category being 

regulated. With respect to the cement industry, this evaluation must now include an evaluation of 

the variability of contaminants such as mercury and total hydrocarbons throughout the industry.

Response: This comment appears to misapprehend the MACT floor process. In assessing which 

performers are best, EPA cannot look to ‘representative’ raw materials for the industry as a 

whole, any more than EPA could examine ‘representative’ baghouse performance. EPA must 

focus on the performance of the best performers. This means assessing the inputs of these 

sources, not others (unless performance of best performers can reasonably be interpreted from 

aspect of other sources’ performance).

2.3.4 Top 5 versus 12 Percent

Comment: One commenter (2898) disagreed with an alternative reading of the MACT floor 

requirements that allowed EPA to consider the emissions of the 5 lowest-emitting existing 

sources instead of the emissions of the lowest-emitting 12 percent of existing sources in setting 

the standard. The CAA unambiguously states that emission standards established pursuant to the 

MACT floor mechanism shall not be less stringent than the average limitation of the best 

performing 12 percent of existing sources, for which the EPA has emissions information, in a 

category or subcategory with 30 or more sources. Basing the standard on the 5 best performing 

sources would violate this mandate by letting the standard be less stringent than the emissions 

performances of the best-performing 12 percent of existing sources and is not allowed by the 

language of the CAA.

Commenter 2816 stated that EPA should not adopt an alternative interpretation of data required 

to set an existing floor. The commenter stated that basing the floor on 5 sources rather than the 

best performing 12 percent is contrary to the language of CAA §112. This interpretation also 

favors industries whose members, for whatever reason, are unwilling to submit test data, or are 

unwilling to participate in emission stack tests for the purposes of data collection by EPA. The 

result is that EPA has limited data to work with and is subsequently criticized for establishing 

standards based on limited data. It is incumbent upon industry to submit sufficient data so that 

the range of facility types and emission levels are adequately represented.

Commenter 2824 recommended that the floor limit be the best-performing 12 percent of existing 

sources with an energy efficiency requirement such as the energy star award.
47

Response: EPA believes its interpretation to be compelled by the statutory text.

Comment: Several commenters (2845, 2846, 2874, and 2915) stated that EPA is proposing to 

calculate MACT floors by averaging the top 12 percent of sources for which CEMS data are 

available (even if that amounts to less than 30 sources), rather than by considering the top 

12 percent of sources for which EPA has emissions information. As a result, EPA is proposing to 

establish the MACT floor based on data from only 2 sources. The commenters stated that CAA 

§112(d) obligates EPA to set the MACT floor looking at no fewer than 5 sources, recognizing 

the value of relying on the maximum amount of data available.

Commenter 2841 stated that the use of a minimum of five facilities should be adopted in the 

establishment of THC standards as well as the other standards in this proposed regulation. The 

establishment of requirements based on a small amount of data would run counter to the intent of 

the CAA in utilizing data that is truly representative of the best-performing facilities throughout 

an entire industry.

Commenter 2841 stated that in previous MACT rulemakings, EPA used the five best performing 

facilities if the number of facilities was less than 30. Consistent with these prior rulemakings, the 

commenter stated that this approach should be used for this proposed Portland Cement NESHAP 

rule and that EPA needs additional data points in order to appropriately set limits for the industry

as a whole.

Response: See response in preamble

Comment: Two commenters (2890 and 2916) stated that EPA must base their emission limits on 

12 percent of the total number of sources, and not exclude facilities’ data. The commenters 

recommended that EPA not make emission estimates for only a small subset of sources to 

determine the MACT floor. If sufficient information is available for a source, such as its size, 

control level, and other source-specific parameters, an estimate should be developed, as allowed 

by the Courts, and the source included in the count of sources for which the Administrator has 

emissions information. Limiting this estimation to sources at the same site or same company is 

arbitrary and should not be done. Emission estimates based on the average emission factor for a 

subcategory should be allowed.

Response: EPA believes its interpretation to be compelled by the text of the statute.

2.3.5 Area Sources in HCL Floor Development

CAA intent

Comment: One commenter (2832) opposed the inclusion of actual and/or synthetic area sources, 

with or without control devices, for any purpose in this major source NESHAP standard. The 

commenter stated that there is nothing in §112 that allows EPA to deem an area source as a best 

performing source for major sources and nothing that allows EPA to include area sources as part 

of a MACT pool.
48

Commenter 2916 stated that it is unlawful for EPA to group major and area sources for purposes 

of setting MACT. By blending area and major sources together for standard setting purposes, 

EPA has created a hybrid major/area source category that is not authorized under §112. 

Response: In the final rule, no data from natural or synthetic minor area sources are being used 

to establish the standard for HCl.

Establish GACT standards 

Comment: One commenter (2887) stated that EPA should develop generally available control 

technology (GACT) standards (or management practices) for area sources under §112(d)(5) for 

the pollutants listed in §112(c)(6). EPA could minimize the economic impact on all area sources 

by subjecting them to GACT for the §112(c)(6) pollutants. Alternatively, the EPA could create a 

subcategory for area sources that are small entities and subject this smaller number of sources to 

GACT (or management practices). This would satisfy the policy behind Small Business 

Regulatory Enforcement Fairness Act (SBREFA) as implemented by EPA policy (to minimize 

the economic impact on small entities while still meeting the mandates of the CAA). 

Response: EPA explains in the preamble to the final rule its various dispositions for applying 

standards to area cement kiln sources.

Comment: One commenter (2887) stated that for HAPs that are not listed under §112(c)(6), 

EPA should establish GACT (or management practices) for area sources under §112(d)(5), and 

not regulate area sources under MACT for non-section 112(c)(6) pollutants. The commenter 

stated that, specifically, EPA proposed limits for PM emissions as a surrogate for non-volatile 

metal HAPs (arsenic, cadmium, beryllium and lead) on cement manufacturing facilities that are 

area sources. Alternatively, the EPA could choose to not regulate area sources or a subcategory

of area sources that are small entities for these pollutants. Emissions from area sources, and even 

more so from the subcategory of area sources that are small entities, are very small.

Response: EPA explains in the preamble to the final rule its various dispositions for applying 

standards to area cement kiln sources.

2.3.6 Legal

Removal efficiency standards vs emission limits

Comment: One commenter (2898) supported EPA’s decision to not rank best performers based 

on their relative mercury removal efficiency. Relying on mercury removal efficiency in setting 

the MACT floor for the portland cement manufacturing industry would downplay the role of 

HAP inputs on emissions. EPA characterizes Brick MACT’s statement that best performers are 

those emitting the least HAP as appearing arguably in dicta. However, the Brick MACT Court 

itself characterizes the statement as the holding of the Cement Kiln case. Brick MACT, 479 F.3d 

at 880 (relying on Cement Kiln’s holding that §7412(d)(3) requires floors based on the emission 

level actually achieved by the best performers or those with the lowest emission levels). The 

proposed alternative of setting the MACT floor on the basis of percentage of emission reduction 

achieved by sources would minimize, if not eliminate, the consideration of cleaner inputs in 
49

setting MACT floors, as EPA acknowledges, and is therefore contrary to statutory dictates and 

case law.

Response: See response in preamble to final rule.

Comment: Several commenters (2831 and 2901) stated that EPA retains considerable discretion 

on how to set MACT floors. The commenters supported the Agency’s authority to set floor 

standards based on control efficiency, or any method as long as their method reasonably 

estimates the performance of the relevant best performing plants. There is nothing in the court’s 

decisions that requires EPA to use the straight-emissions approach favored in this rule. The 

commenter stated that the court has expressly decided that a straight-emissions or arithmetical 

methodology is not required, and EPA’s technology based approach that estimated performance 

rather than deriving the standards through an arithmetic straight emissions approach, as long as 

they result in a reasonable estimate of the performance of the best controlled units, is supported 

by the courts. According to the commenter (2901), Brick MACT does not endorse a straight 

emissions approach; nor could it. To do so would mean that the Brick MACT court was 

overturning the Chevron step one holding in Sierra Club and National Lime II, something that it 

cannot do.

Response: See response in preamble to final rule.

Comment: One commenter (2832) stated that EPA has incorrectly focused on the term emission 

limitation in proposing a numeric allowable HAP emissions MACT floor. In fact, EPA is 

required to set emission standards, not necessarily numeric emissions limitations in creating a 

MACT floor. The Court in the Brick decision did not require otherwise. In fact, the wording of 

§112, a reduction in emissions that is achieved in practice by the best controlled similar source 

contemplates air emissions control equipment whose manufacturer’s specified HAP emissions 

removal efficiency for all HAPs is the highest percentage achieved in practice in the industry in 

question. Inlet and outlet stack testing that confirms the efficacy of air emissions control 

equipment is the legal requirement of the §112(d)(3). The law does not state that EPA is required 

to set numeric HAP emissions limits. In identifying the best performing sources, the 

Administrator is directed by §l12(d)(3) to review emissions information, not numeric emissions 

data or emissions stack test reports. Sections 112(j)(5) and 1l2(i)(5) also support this reading of 

§112(d)(3). Each refers to demonstrations of emissions reductions of a stated numeric percentage 

as a means of meeting MACT requirements. EPA’s discussion of the beyond-the-floor 

evaluation confirms this approach as well. 

Response: The commenter does not address the issue of how non-numeric percent reduction 

standards address the issue of raw material and fuel HAP levels and their contribution to 

emissions. EPA cannot ignore such contributions in determining which sources are best 

performing, and their level of performance. At the least, EPA is adopting a reasonable approach 

of establishing numerical standards, and using a ranking methodology based on which sources 

emit the least of the HAP in question, on a normalized basis (for Hg and PM) and considering 

their performance over time (variability).
50

Standards must be achievable

Comment: One commenter (2844) stated that the CAA requires that lawfully promulgated 

NESHAP standards must be achievable. Section 112(d)(2) of the Act, 42 U.S.C. §7412(d)(2), 

required EPA to establish emission standards for HAPs that require the maximum degree of 

reduction in emissions taking into consideration the cost of the emission reduction and non-air 

quality health and environmental impacts and energy requirements, that the EPA Administrator 

determines is achievable for new or existing sources. Further, House Rep. 101-490, Part 1 (328) 

stated that The Committee expects MACT to be meaningful, so that MACT will require 

substantial reductions in emissions from uncontrolled levels. However, MACT is not intended to 

require unsafe control measures, or to drive sources to the brink of shutdown. The commenter 

noted that the proposed portland cement proposed NESHAP standards do not comply with 

§112’s achievability requirements.

Response: See preamble to final rule for response.

Comment: Commenter 2844 stated that EPA’s conclusion that §112(d)(3) and/or Brick MACT

requires or even permits the Agency to ignore the achievability requirements of §112(d)(2) is an 

unreasonable reading of the statute and of Brick MACT. The Agency retains more than sufficient 

discretion to devise NESHAP standards that successfully bridge the tension between achieved 

and achievable in §112’s standard-setting provisions by appropriately using both 

subcategorization and variability methodologies.

Response: See response in preamble.

Comment: One commenter (2844) stated that EPA’s floor setting methodology does not comply 

with three of Brick MACT’s requirements: 

 Floors must be based on emissions achieved in practice by best-performing sources; 

 EPA’s use of variability factors and methodologies to adjust reported emissions data must 

be based on demonstrated relationships, so that the floor setting methodology serves to 

reasonably estimate or predict the performance of the best performing sources; and 

 EPA must consider the impact of nontechnology factors, such as raw material and fuel 

inputs, on a source’s emission control levels.

Commenter 2844 stated that in the portland cement proposal, EPA set MACT floor levels that 

reflect the specific conditions at the time the data were generated and do not include any of the 

operational variability. The commenter suggests that EPA must look beyond its snap shots of 

performance to make a reasoned evaluation and estimation of all operating conditions and factors 

that might impact the level of actual emissions from those kilns in practice, and adjust their 

reported short term test data appropriately. EPA can and should adjust raw emissions results to 

estimate sources’ achieved emissions levels when setting MACT floors and standards. Since 

Brick MACT, EPA’s methodology now must be able to reasonably estimate the impacts of 

variability associated with both technological and nontechnological factors over the full range of 

circumstances. 

Response: See response in preamble to final rule.
51

Comment: One commenter (2844) also stated that EPA adopted a floor setting methodology that 

is based on using lowest reported emission results with minimal variability adjustments to 

estimate emission control achieved in practice by best performing sources. EPA considered testto-test variability, but did not consider the inherent variability due to raw materials, product mix, 

fuels, operating conditions and plant types. The commenter stated that EPA has not evaluated or 

validated whether its methodology accurately estimates emissions control achieved in real world 

circumstances at sources.

Response: See response in preamble.

Comment: One commenter (2844) stated that EPA cannot evaluate floors using methodologies 

that focus exclusively on technology if the resulting standards do not reflect actual average 

limitation[s] achieved (Brick MACT, 479 F.3d at 882). The commenter concludes that Brick 

MACT requires EPA to address the role of nontechnological factors that impact emissions in 

setting floors and EPA must develop a methodology that accurately estimates the actual 

emissions achieved in practice by the best performing sources under a variety of operating 

conditions, taking into consideration testing and technological and nontechnological variability.

As proof that EPA failed to properly account for sources’ variability in setting the standards, the 

commenter (and commenter 2845) included a chart purporting to demonstrate that the kilns 

comprising the pool of best performers for each HAP could not themselves meet the proposed 

standard. 

Response: See response in preamble.

Comment: One commenter (2844) stated that the proposed standards cannot be viewed as 

assessing the emissions control achieved by best performing sources, given that there is no single 

existing source that meets the standards simultaneously and for two of the pollutants, no existing 

units meet the standards without operational changes. The EPA has an obligation to devise 

appropriate variability methodologies and to collect the information necessary to do so.

Response: EPA has responded above and rejected the argument that the statute unambiguously 

compels that floors be established on a complete facility basis.

Worst Reasonably Forseeable Circumstances

Comment: Several commenters (2844, 2846, and 2915) stated that EPA’s floor methodology

does not estimate emission control achieved under the worst reasonably foreseeable 

circumstances. EPA must estimate emission levels achieved under the worst foreseeable 

circumstances in order to reasonably estimate achieved in practice control levels. The proposed 

portland cement rule proposes that sources must achieve compliance with the proposed floor 

standards at all times, including periods of startup, shutdown and malfunction (SSM) events. 

Because the data to estimate the appropriate variability factor for SSM events do not exist and 

are technologically impracticable to develop, EPA cannot reasonably set a floor based on 

compliance during SSM events. 

Commenter 2845 stated that the policy and common sense approach is recognized and required 

by the D.C. Circuit. Once the similar sources category is established, the EPA must identify the 

lowest emission limitation that has been achieved in practice by these sources. In another MACT 
52

case, the D.C. Circuit has held that the phrase achieved in practice refers to the performance of 

the source under the worst foreseeable circumstances (Sierra Club v. EPA, 167 F.3d 658, 664, 

D.C. Cir. 1999). 

Commenter 2845 stated that EPA should follow its own common sense approach and the 

directive of the D.C. Circuit and develop MACT standards that consider the long term emission 

variations in portland cement facilities.

Response: First, EPA has established separate standards for startup and shutdown, so these 

operating conditions are not part of the performance EPA is evaluating in developing the main 

MACT floors. EPA also explains in the preamble to the final rule why it reasonably did not 

consider malfunction events in developing those floors, which reasons include that EPA is 

therefore adding to the final rule an affirmative defense to civil penalties for exceedances of 

emission limits that are caused by malfunctions. Since malfunctions, if properly demonstrated, 

would not be considered to contribute to an exceedance of the standard (for purposes of civil 

penalties), EPA surely need not consider malfunctions in assessing best performing sources’ 

performance and establishing MACT floors.

Second, EPA agrees that long term performance of sources – their variability – is to be 

considered both in determining which sources are best performing and what their level of 

performance is. EPA has reasonably done so in establishing this NESHAP.

CAA requires emission reductions by 94 percent of sources

Comment: One commenter (2890) stated that the setting of a MACT floor requires 94 percent of 

any population of sources, including those that had never engaged in any emission reduction 

techniques, to either add air pollution control devices or shut down processes, without the 

consideration of costs. The floor should identify what the best actual sources in the category are 

doing; presuming that if the average of the top 12 percent was achieving this level of control in 

the absence of a rule, achieving that level of control must have been at a reasonable cost.

Response: The commenter is correct that costs cannot be considered in establishing MACT 

floors and that by virtue of the floor process the statute implicitly assumes that the great majority

of plants will have to upgrade their performance to meet promulgated standards of at least the 

designated minimum stringency.

Exclusion of sources engaged in mining

Comment: Several commenters (2890 and 2916) stated that Congressional intent in the 

establishment of MACT shows a clear intention to exclude mined minerals: For categories and 

subcategories of sources of hazardous air pollutants engaged in mining, extraction, 

beneficiation, and processing of nonferrous ores, concentrates, minerals, metals, and related inprocess materials, the Administrator shall not consider the substitution of, or other changes in, 

metal- or mineral-bearing raw materials that are used as feedstocks or materials inputs, or 

metal- or mineral-bearing materials processed or derived from such feedstocks or materials in 

setting emission standards, work practice standards, operating standards or other prohibitions 

or requirements or limitations under this section for such categories and subcategories. The 

prohibition of the preceding sentence shall not apply to the substitution, modification, or 
53

changes of chemicals (not including metal- or mineral-bearing materials) used in mining, 

extraction, beneficiation, or processing of nonferrous ores, concentrates, minerals, metals and 

related in-process materials which is necessary to reduce air emissions of such chemicals and 

for which substitutes that are safe and effective in performing the intended function of the 

chemical to be substituted are reasonably available [From Joint Explanatory Statement of the 

Committee of Conference, H.R. Rep No. 101-952, at 339 (1990)]. EPA used this same quote in a 

previous court case involving the secondary copper MACT [Sierra Club v. EPA (No. 02 -1253)]. 

Commenter 2890 suggested that after mined minerals are eliminated from consideration for 

MACT, several options for establishing the best controlled sources are:

 Control of the mercury and other pollutants that are not in materials other than the 

limestone typically mined onsite.

 Any emission control equipment or other practice that reduces the amount of emissions 

that are ultimately emitted from the processing of the mined material.

Response: See preamble to final rule for response.

Consideration of variability

Comment: One commenter (2845) stated that case law and policy dictate that the EPA must 

consider variability in establishing MACT standards, and the approach used by EPA in 

Prevention of Significant Deterioration (PSD) permitting should also apply in establishing 

MACT standards. To evaluate the emission limits achieved by existing sources, EPA is required 

to develop methodologies for estimating the variability associated with all factors that impact a 

source’s emissions, including process, operational and non-technological variables (see Nat’l 

Lime Ass’n v. EPA, 627 F.2d 416, 443, D.C. Cir. 1980). While courts have affirmed EPA’s 

authority to choose a methodology designed to estimate emissions in setting the MACT floor, the 

courts have also made clear that EPA’s method must allow a reasonable inference as to the 

performance of the top 12 percent of units (Cement Kiln Recycling Coalition v. EPA, 255 F.3d 

855, 862 (D.C. Cir. 2001) (citing Sierra Club v. EPA, 167 F.3d 658, 663, D.C. Cir. 1999). 

Accordingly, the Court of Appeals for the D.C. Circuit has stated that EPA must show not only 

that it believes its methodology provides an accurate picture of the relevant sources' actual 

performance, but also why its methodology yields the required estimate (Cement Kiln Recycling 

Coalition, 255 F.3d at 862).

Response: See response in preamble.

Comment: One commenter (2845) further stated that EPA has a clear policy of considering 

long-term variability when establishing enforceable emission rates. In considering appropriate 

enforceable emissions rates in PSD permits under the CAA, the Environmental Appeals Board 

has held that a permitting authority is not required to set the Best Available Control Technology

(BACT) emissions limit at the most stringent emissions rate that has been demonstrated in 

practice by a facility using similar emission controls (In re Newmont Nevada Energy Investment, 

12 E.A.D. 429, 441-42, EAB 2005 (citing Kendall New Century Dev., 11 E.A.D. 40, 53, EAB 

2003). The Board has recognized the use of safety factor[s] in the calculation of permit limits to 

take into account both the variability and fluctuation in the expected performance of pollution 
54

controls and the fact that setting emissions limitations for one facility at the highest control 

efficiency demonstrated at another facility would make violations of the permit unavoidable (Id. 

at 442, citing In re Masonite Corp., 5 E.A.D. 551, 560, EAB 1994).

Response: Although BACT determinations under PSD are by no means analogous to 

determining MACT floors (cost is considered in determining BACT, for example), EPA agrees 

that consideration only of single data points may not adequately represent sources’ performance 

over time, and EPA consequently is not utilizing that methodology in this rule. EPA also has 

taken variability into account during the process of establishing the emission limits for this rule.

Comment: Commenters 2844, 2845, and 2916 objected to EPA’s interpretation of CAA 

Sections 112(d)(2) and 112(d)(3) and the Brick MACT (Commenter 2845 provided a white paper 

as an appendix to their comments for the HWIMI MACT proposal, dated December 01, 2008.). 

The paper, entitled Implications of the Brick MACT Decision on EPA’s Discretion in Setting 

MACT Floors, discusses variability at some length. The paper’s main points were:

 The Agency has chosen to focus on setting MACT floors based on lowest emitting 

sources derived from limited test results that are not appropriately adjusted to account for 

stack test variability. 

 The Brick MACT decision holds that EPA must base MACT floors on achieved 

emissions control rather than control technology, but it does not require EPA to ignore 

operational variability in determining those floors.

 Variability methodologies must reasonably estimate or predict emissions or variability 

through a demonstrated relationship between the data used and the performance intended 

to be estimated. 

 Non-technological factors (i.e. raw materials and fuel) must be considered in determining 

emission control achieved by best performers.

 It is within the EPA’s discretion to define the best performing sources. 

 EPA should estimate variability in determining achieved emissions.

 The Agency can and must seek appropriate data from regulated entities and other 

stakeholders, and to develop appropriate fact-based estimating methodologies on the data 

available.

Response: See response in preamble.

Brick MACT

Comment: Several commenters (2834, 2844, 2845, and 2859) stated that the Brick MACT 

decision makes the expectations of what is expected by EPA in regards to setting the floor very

clear: 

 Floors must be based on emission control achieved in practice by the best performers

 Variability methodologies must reasonably be calculated to estimate such actual 

performance levels
55

 Nontechnological factors that impact emissions must be considered in determining the 

achieved emissions levels 

 In devising new methodologies to set lawful floors, EPA must ensure that compliance 

with §112(d)(2) general standard setting criteria is also met.

 EPA can use discretion to define the factors necessary to establish a floor under 

§112(d)(3) that meet the CAA’s statutory intention to be technology-forcing and require 

compliance with the best that has been demonstrated to be achieved in practice while 

considering costs, other non-air health and environmental impacts, and energy impacts 

when defining achievable MACT standards.

Based on these points, the Brick MACT decision requires that EPA’s floor analyses include a 

review of the best performers and consideration of variable factors that can affect emissions 

achieved in practice by the pest performance sources. EPA’s analyses and methodological 

choices must be based on facts and records that support its final determination. It is appropriate 

that a full review of the existing records and the development of new data be considered in 

making a final decision.

Response: The case law makes overwhelmingly clear that the requirement in section 112 (d)(2) 

that MACT standards be achievable after considering various factors does not supersede the 

requirement of section 112 (d)(3) that they be of minimal stringency as determined by the criteria 

for establishing MACT floors. See, e.g. Cement Kiln Recycling Coalition, 255 F. 3d at 861-62.

As discussed in the preamble and in other comment responses, EPA has carefully assessed best 

performers’ short- and long-term variability for each HAP in estimating their performance.

2.3.7 Format of Emission Limits

Use CEMS units as limits

Comment: One commenter (2638) recommends the EPA use plain language and units that can 

be related to ambient measurements for its emission limits. The units currently proposed require 

modifying the direct CEMS output with inputs under the control of the plant, which make the 

results un-interpretable by anyone wanting to make comparisons with ambient measurements or 

health effects; or the CEMS concentration readings should be required to be posted/reported.

Response: Emission limits are typically normalized to some type of production or raw material 

input value because this allows comparison (and ultimately the ability to set a single standard) 

for different sized facilities. As we noted in the NSPS proposal, the current NSPS and limits (and 

NESHAP limits before today’s amendments) for PM are expressed on a pound of PM per ton 

(lb/ton) of dry feed input format. See 73 FR at 34075-76. In this final NESHAP (and NSPS) we 

are adopting a new normalizing parameter of lb/ton of clinker – i.e., normalizing based on kiln 

output rather than input for both PM and mercury.

We noted at proposal of the NSPS that adopting an output-based standard avoids rewarding a 

source for becoming less efficient, i.e., requiring more feed to produce a unit of product, 

therefore promoting the most efficient production processes. 73 FR at 34076.
56

EPA therefore proposed that all of the NSPS (for PM, NOx, and SO2) be normalized by ton of 

clinker produced, and later proposed the same parameter for the two standards in the NESHAP 

which are normalized, mercury and PM. 73 FR at 34076; 74 FR at 21140.

In the final NESHAP (and NSPS) we are therefore adopting a new normalizing parameter of 

lb/ton of clinker – i.e. normalizing based on kiln output rather than input – for mercury and PM 

in the NESHAP, and for PM, NOx, and SO2 in the NSPS.

We are currently developing a reporting mechanism for CEMS data. We will consider these 

comments as we continue that effort. In concept, the CEMS data base would be publically

available. However, the reporting frequency has not been developed.

See the preamble discussion under format of the normalized standards in the NESHAP and the 

NSPS, for more information on EPA’s decision.

Use of kiln feed vs clinker in emission limits

Comment: Commenters (2830, 2844, 2845, 2859, and 2879) stated that they supported emission 

limitations in pounds of pollutant per ton of kiln feed rather than as pounds per ton of clinker 

produced. Commenters 2844, 2859, and 2879 noted that clinker conversion factors may vary

from plant to plant and may give erroneous results. According to the commenters, clinker weigh 

systems are not common in the cement industry and will not improve accuracy over a kiln-feed 

measurement system with an appropriate clinker factor, as is commonly used. On a short-term 

basis, clinker output from the kiln will fluctuate while the kiln feed rate remains constant. The 

variable nature of clinker production creates more inaccuracy in short-term (hourly) clinker 

weigh data than the +/- 5 percent specified by the EPA. If the standards are based on tons of 

clinker, then the kiln owner should have an option to determine clinker weight from feed that 

should not require EPA approval of the method and the averaging time and accuracy

requirements should reflect what is practical, achievable and useful.

Commenters 2844 and 2845 asked for clarification from EPA on proposed language regarding 

alternative methods to measuring clinker production and the need to obtain Administrator 

approval for such methods. The Proposal also stated that the use of a system that directly 

measures kiln feed rate and uses a conversion factor to determine the clinker production rate is 

an acceptable method. The commenter states that it is unclear whether EPA believes that 

Administrator approval is required to utilize such a method when EPA identifies in the 

regulations that the method is acceptable. In any event, cement plants should be given the option 

of complying with the regulation by either measuring the clinker production or by measuring kiln 

feed and developing a clinker factor to calculate clinker production. Almost all cement plants 

measure kiln feed and develop a clinker factor. Such a method requires periodic adjustments to 

the clinker factor and justifies a longer time-frame than hourly for determining clinker 

production.

Response: See the response to the comment above, regarding the format of the standards.

Commenters maintain that the measurement of kiln output is not as exact as the measurement of 

kiln input, and that many kilns have not installed clinker measuring equipment. These objections 

do not necessitate normalizing by inputs. Most commenters also stated that kiln feed could be 
57

accurately measured and also indicated that most facilities currently derive reasonable feed-toclinker conversion factors from these measurements. Kilns already calculate clinker production 

in this way when required to meet emissions limits normalized by clinker production, as many 

NSR and PSD permits for cement kilns presently do.

Since it appears from comments that the equipment to accurately measure clinker is not typically

installed in this industry, we must assume these facilities use a feed-to-clinker conversion factor 

to calculate clinker production on whatever time basis is necessary (e.g., daily, hourly, etc.).

Therefore, we have modified the rule language to more clearly provide the option allowing 

facilities to measure feed inputs and to use their site specific feed/clinker ratio to calculate 

clinker production (and that no prior approval from a regulatory authority is necessary to do so).

Facilities would be allowed to use a constant feed/clinker ratio in accord with their usual cycles 

for determining such ratios, typically on a monthly basis when clinker inventories are reconciled.

Commenters were nonetheless concerned that because clinker/feed ratios change somewhat and 

are only re-determined at the end of a cycle, a slight change in clinker/feed ratio, determined at 

the end of the cycle, would show lack of compliance without an opportunity to alter operation.

To obviate this concern, the rule provides that facilities are not required to retroactively update 

clinker production estimates after re-computing feed/clinker ratios. We would not expect that the 

clinker/feed ratio will change significantly from month to month, so we do not see this as 

creating a situation where facilities will be able to have large amounts of excess emissions but 

still be considered in compliance (especially since the 30-day standards are all rolling averages).

See the preamble discussion under format of the normalized standards in the NESHAP and the 

NSPS, for more information on EPA’s decision.

Accuracy of determining kiln input or output

Comment: One commenter (2845) stated that kiln feed accuracy should be established on a 

longer timeframe than one hour:

 Daily clinker production typically is estimated by measuring the kiln feed rates and 

utilizing a clinker factor to convert kiln feed rate (which includes kiln feed and kiln dust 

returned) to clinker production rate. Several variables in the calculation are measured are 

not determined more frequently than a weekly basis and can vary on a short term basis. 

Another variable, dust loss, is estimated, not measured. It cannot be expected to have a 

clinker factor in the short term with an accuracy of better than +/-10 percent. Tracking 

these variables on a short term basis is not practical. 

 Plants typically measure clinker inventory daily, and conduct more detailed physical 

inventories on a monthly and/or quarterly basis. 

 Plants that utilize a single clinker handling system for multiple kiln lines cannot confirm 

the clinker factor for each individual kiln.

Response: See the response to the comment above, regarding the accuracy of determining kiln 

input or output, and the latitude for determining site-specific clinker factors. See the preamble 

discussion under format of the normalized standards in the NESHAP and the NSPS, for more 

information on EPA’s decision.
58

Grain loading format

Comment: Commenter 2859 stated that as an alternative to basing the PM standard on pounds 

per ton dry feed, EPA could use a grain loading standard (i.e., gr/acf).

Response: See the preamble discussion under format of the normalized standards in the 

NESHAP and the NSPS, for more information on EPA’s decision regarding format of the 

standard.

2.3.8 Other

Central stack

Comment: Many commenters (2893, 2975, 2990, 2992, 3001, 3003, 3005, 3017, 3022, 3034, 

3038, 3045, 3052, 3056, 3059, 3063, 3073, 3074, 3077, 3089, 3098, 3107, 3117, 3124, 3125, 

3128, 3130, 3131, 3132, 3160, 3226, and 3227) stated that EPA should require that all cement 

kilns have one central stack. Without a central stack, the emissions from the kiln cannot be 

adequately monitored, and the CEM required in the proposed rule would not be viable for 

monitoring emissions and confirming emissions reductions. In addition, necessary scrubbers 

and/or other pollution control devices require a central stack for placement. 

Response: The majority of cement kilns are equipped with control devices that are equipped 

with a central stack. However, those kilns using positive pressure fabric filters may be equipped 

with roof monitors instead of stacks. In the case of PM emissions, such devices can be equipped 

with a bag leak detection system, which is a viable monitoring alternative to PM CEMS and 

explicitly allowed in the rule as a monitoring alternative. In other cases, the source may have to 

retrofit the control device outlet to install one or more stacks. Finally, sources can always request 

EPA approval under the part 63 General Provisions (§63.7(f)) to use an alternative method to 

accommodate site-specific conditions. For example, open-path monitoring may be viable in 

some situations.

2.4 General Legal Issues

Comment: One commenter (2901) stated that National Lime II stands for the principle that as 

long as the facility is controlling pollution, the levels achieved can be considered, even if the 

facility was not intending to control the specific HAP. The commenter noted that the major issue 

in National Lime II was whether EPA could decline to set an emission standard for HAPs that no 

facility in the source category was controlling with technology. The National Lime II court was 

saying that if a facility was already controlling its emissions, the fact that it was not intending to 

control the HAP in question could not be a reason for EPA to consider the pollutant 

uncontrolled.

Response: The commenter correctly describes this portion of the second National Lime decision.

2.4.1 Subcategorization

Comment: One commenter (2844) stated that subcategorization based on nontechnical factors 

may result in opportunities for reasonable beyond the floor (BTF) standards. It would be 
59

appropriate for EPA to base the NESHAP standard on BTF levels that reflect application of the 

nontechnological factor as an intended control strategy under §112. However, while Brick MACT

requires EPA to take into account emissions data irrespective of whether it was achieved through 

specific intended operational choices or control technology, nowhere did the court say EPA had 

to or even could simply assume that a source’s emissions in practice would be invariably 

equivalent to a particular observed emission level and that all operational and nontechnological 

factors that happen to be in effect on the day of testing could be assumed and required to be in 

effect, in the future.

Response: EPA agrees that sources’ variability is unlikely to be encompassed by a bare single 

measurement. It is for this reason that EPA developed all of the standards based on substantial 

data gathering augmented where appropriate by statistical estimates of variability.

Comment: One commenter (2844) stated that if EPA determines that raw material inputs impact 

the emission control achieved in practice by the best performing sources, EPA must assess that 

impact. Given that the raw material input varies, the commenter stated that EPA’s variability 

methodology must include that variability in estimates of emission control achieved by the 

sources; further, if the variability in the raw materials used by the differing units is significant, 

EPA may determine that subcategorization is the most reasonable way to regulate the industry to 

ensure that each source is subject to the most stringent floor level of control reasonable to apply

to sources utilizing raw material sources of similar HAP input.

Response: EPA’s reasons for not creating a subcategory for the two plants with exceptionally

high mercury emissions due to limestone quarry mercury content is set out in the preamble to the 

final rule.

Comment: One commenter (2846) stated that EPA has authority to establish subcategories of 

sources when issuing standards. Subcategorization would allow for a workable MACT standard 

and allow sources that are limited in certain ways to apply the best available control technology

for their facilities and still comply with the standards. The commenter believes that 

subcategorization for on the basis of feed material quality is wholly appropriate and required by 

law.

Commenters 2832 and 2859 support subcategorization as permitted in the Concurring Opinion in 

the Brick decision. This support includes but is not limited to subcategorization according to 

process operations (type, raw materials, chemistry/formulation data, associated equipment and 

final products), emission characteristics (amount and type of HAP), and air pollution control 

device applicability, opportunities for pollution prevention, and existing regulations or guidance 

from states and other regulatory agencies.

Commenters 2776, 2777, 2810, 2814, 2833, 2859, 2904, 2915, 2920, 2926, 3204, 3212, 3214, 

and 3215 supported the use of subcategorization in the proposed rule. Commenter 2915 stated 

that in allowing EPA to create subcategories, §112(d)(4) does not restrict subcategorization to 

only factors that affect emissions. The provision requires EPA to establish regulations for each 

category or subcategory on the schedules set out in §112. EPA states in the preamble, EPA may 

create a subcategory applicable to a single HAP, rather than to all HAP emitted by the source 

category. While the commenter disagreed with EPA’s approach to MACT standard-setting, if 
60

EPA continues to follow that HAP-by-HAP approach to MACT standard-setting, then EPA 

should create different subcategories for each HAP rather than one set for all HAPs.

Response: Because EPA is determining not to exercise its discretion to create a subcategory for 

a subcategory for kilns with exceptionally high mercury emissions due to high levels of mercury

in their limestone quarries, it is unnecessary to respond to these comments.

Comment: One commenter (2824) suggested that for the best protection of human health, create 

an optimized mercury subcategory by evaluating increased exposure from foreign plants in 

response to plants that could shut down due to technology or economics while varying 

construction demand. 

Response: This comment does not track the MACT standard setting process prescribed by law, 

which requires technology-based determinations based at a minimum on performance of certain 

best operated or controlled domestic plants in the source category.

2.4.2 Fly Ash Ban

Comment: Several commenters (2816 and 2835) stated that it was appropriate for EPA to 

remove the prohibition on kilns using fly ash from utility boilers using activated carbon injection 

for mercury control. Given that the mercury emission limit will apply regardless of fuel or fuel 

substitutes, this prohibition is no longer needed.

Response: EPA agrees.

Comment: One commenter (2828) suggested that EPA retain a ban on cement kilns 

pyroprocessing (or heating) of fly ash from power plants if the mercury content of the fly ash has 

been increased above its normal concentration by mercury capture systems at the power plant. 

Until there is certainty on how coal- and oil-fired electric utility steam generating unit (EGU) 

will be required to account for mercury re-emissions from cement plants that acquire their fly 

ash, the cement MACT rule should maintain a ban on the use of fly ash with captured mercury. 

The commenter encouraged EPA to retain the proposed mercury emission standard, and 

supplement it with a continued ban on fly ash pyroprocessing if the ash has elevated mercury or 

if the power plant producing the ash took credit for the reductions. The commenter suggested 

that this rule, as well as the upcoming EGU MACT rule, require coordination between fly ash 

producers and potential fly ash users so that re-emission of mercury is properly accounted for, 

and we do not have the problem of mercury being emitted to the atmosphere at one location after 

being controlled at another. 

Response: The technology-based standard for mercury reflects the minimum level of 

performance achieved by the average of the best performers, or the best controlled similar 

source. If other kilns can meet these limits while importing fly ash, there is nothing in section 

112 (d)(3) which prohibits them from doing so, since the provision is technology-neutral. So 

long as the standards are satisfied, the statute does not dictate how.

Comment: One commenter (2638) stated that coal ash is enriched in other urban HAP metals 

besides mercury. These enrichments of coal are on the order of 5 to 10 fold. With these 

enrichments, it will important that emission limits be developed for each individual urban HAP 
61

metal and be correspondingly monitored. Without this assurance, the EPA should not allow coal 

ash to be used in the manufacture of portland cement.

Response: Given that the PM emission limit (as a surrogate for nonvolatile metal HAP) will 

apply regardless of fuel, fuel substitutes, or raw materials, this prohibition is not needed. The 

standard for PM reflects the minimum level of performance achieved by the average of the best 

performers, or the best controlled similar source. If kilns can meet these limits while 

incorporating coal ash, there is nothing in section 112 (d)(3) which prohibits them from doing so, 

since the provision is technology-neutral. So long as the standards are satisfied, the statute does 

not dictate how.

2.4.4 Other

Offsets

Comment: One commenter (2898) stated that any netting or offsets pursuant to NSR must meet 

all CAA requirements. The CAA only allows offsets for incidental emissions reductions that are 

not otherwise required. 42 U.S.C. 172(c)(2). Federal regulations additionally require that 

emissions reductions, in order to qualify as offsets, be surplus, permanent, quantifiable, and 

federally enforceable. 40 CFR 51.165(a)(3)(ii)(C)(1)(i). Longstanding agency guidance, 

including the General Preamble for State Implementation Plans (57 FR 13498, 13552-54, dated 

April 16, 1992), imposes additional restrictions. Per the foregoing, The EPA’s policy for NSR 

offsets is that since hazardous emissions reductions required to meet the MACT standards at 

40 CFR 60 and 61 ... are required by the Act these emissions are not creditable as NSR offsets. 

Memorandum from J. Seitz to B. Hannesschlager re: Crediting MACT Emission Reductions for 

New Source Review (NSR) Netting and Offsets (November 12, 1997).

Response: These comments relate to NSR, which is outside the scope of this rulemaking.

Comment: Several commenters (2845 and 2874) agreed that EPA correctly suggests that surplus 

sulfur dioxide credits could be used for offsets and netting and commended EPA for this 

recommendation that surplus sulfur dioxide emission reductions resulting from the installation of 

a wet scrubber (used to satisfy sulfur dioxide offset requirements) can be used for netting

purposes under the CAA new source review program. Commenter 2874 believed that this is an 

appropriate position and EPA should repeat this statement in the preamble to the final rule, 

making the point clear to regulators dealing with portland cement new source review matters.

Response: See above.

2.5 Mercury Standards

2.5.1 Legal Issues

Subcategorization

Comment: Many commenters (2816, 2828, 2834, 2895, 2898, and 2923) supported EPA’s 

approach of establishing a single national standard, rather than weakening the proposed standard 
62

through the use of subcategorization. According to several commenters (2816, 2834, and 2898), 

EPA properly rejected subcategorizing cement kilns for the following reasons: 

 Under §112(d)(1), EPA can only create subcategories based on classes, types, and sizes

of sources. Since limestone mercury content can vary within a single quarry, kilns with 

proprietary quarries with sections that have high mercury content are not sufficiently

uniform to be considered a class or type. Even for those high-mercury quarries identified 

by EPA, the Agency is not aware of the mercury content of the remainder of the quarry. 

Nor is there any suggestion that a quarry’s mercury content is related to its size. Further, 

the lack of a causal link between limestone mercury content and emission rates makes 

subcategorizing by quarry content untenable.

 Kilns with more mercury-rich limestone would be favored and those with lower mercury

levels disadvantaged. Kilns would be rewarded for selecting the highest mercury

limestone to test for categorization. Thus, the category would create an incentive for kilns 

to concentrate in areas with limestone formations that just exceed the mercury

concentration cut-off for the category. 

 Subcategorization is unnecessary because it is not clear that any outliers exist. EPA 

separated two facilities as having the highest quarry mercury contents and identified 

those sources as potential outliers. But EPA acknowledges that at one of those kilns it 

does not currently have any data on the possibility that this site may have portions of its 

existing quarry that have lower mercury content. They may simply be in sections of their 

quarries that are particularly high in mercury. Creation of a subcategory without further 

evidence it is justified would be arbitrary.

 Creating a subcategory for kilns with quarries that are high in mercury would be a 

continuation of the pattern repeatedly rejected by the D.C. Circuit as violating the CAAsetting emission standards based on a concern about ensuring that its floor is achievable 

by all kilns in the subcategory. If §112 is to meet its purpose of require the maximum 

degree of reduction in emissions, then the standards created pursuant to it cannot be set so 

as to accommodate the heaviest polluters. EPA must heed the D.C. Circuit’s previous 

rejection of efforts to tailor emission standards so as to ensure all sources can meet those 

standards. 

Commenter 2898 agreed with EPA that none of the bases for subcategorization discussed in the 

proposed rule meet the CAA’s guidelines:

 Any basis for subcategorizing must be related to an effect on emissions, rather than to 

some difference among sources which does not affect emissions performance. The 

commenter agreed that subcategorization on the basis of the type of kiln or the presence 

of an inline raw mill is inappropriate because none of these distinctions affects total 

mercury emissions over time.

 Subcategorization on the basis of geographic location is inappropriate because mercury

content can vary significantly from quarry to quarry and even within a quarry, nor does a 

difference in geographic location constitute a difference in class, type, or size. Moreover, 

EPA found no correlation between geographical distribution of mercury emissions and 

total mercury.
63

 Subcategorization based on the practice of wasting cement kiln dust is inappropriate as it 

can be considered a control technology and subcategorization by control technology

would defeat the purposes of the MACT requirement, which is to control the worst HAP 

pollution.

 Subcategorization by total mercury inputs is inappropriate because total mercury inputs 

do not differentiate facilities by size, class, or type because a particular set of inputs are 

not inherent to the operation of the cement facility. Because subcategorization on this 

basis would result in a situation where facilities with higher total mercury inputs would 

have higher total emission limits, it would create the same problems as subcategorizing 

by control technology. 

 Subcategorization on the basis of mercury content of facility’s proprietary limestone 

quarry is inappropriate would essentially be subcategorizing by control technology. As 

Brick MACT confirmed, inputs are a means of emissions control. As with total mercury

inputs, the mercury content of the proprietary limestone quarries does not differentiate 

facilities by size, class, or type. There is nothing about the limestone from the proprietary

limestone quarry that is inherent to the process of the cement facility. While it is true that 

all cement plants have a limestone quarry located near the facility and that facilities are 

often sited based on the location of the quarry, the proprietary nature of the quarry does 

not diminish the fact that the cement facility’s kilns will work equally well with 

limestone from other sources. The only operational difference between limestone from 

the proprietary quarry and limestone from other quarries is cost (for transportation or 

purchase), an impermissible consideration in setting the MACT floor. Separate standards 

would unfairly expose communities near the dirtiest cement facilities to the highest levels 

of mercury pollution from cement plants and leave them with the least protection against 

such pollution. Subcategorization by the mercury content of the limestone quarry runs 

counter to the holding of Brick MACT and other decisions. Brick MACT holds that EPA 

must account for raw material HAP contributions in establishing MACT floors and that 

the proprietary nature or proximity of the raw material does not excuse EPA from 

considering the HAP emission from the raw material in setting the MACT floor.

Commenter 2898 disagreed with the Portland Cement Association’s (PCA’s) (commenter 2845) 

arguments for subcategorization by mercury content of proprietary quarries. The commenter 

provides counterarguments to (PCA’s) citations and interpretations of case law.

Commenters 2842 and 2911 opposed the use of subcategories. Commenter 2911 stated that 

setting separate standards for kilns that use high mercury limestone would be unlawful. 

 The sentence in §112(d)(1) that allows EPA to distinguish among classes, types, or sizes 

of sources within a category or subcategory in establishing standards does not permit 

EPA to set separate standards for cement kilns that merely have limestone quarries 

containing higher levels of mercury. The distinctions between class and type must relate 

to the source itself and not a distinction between the raw materials used by the source. 

Under EPA’s own definition, a quarry is not any part of an affected source.

 EPA states inaccurately that kilns with mercury above a given level might be considered a 

different type or class of kiln because their process necessarily requires the use of that 

higher mercury input (74 FR 21145). EPA does not and cannot identify any kiln whose 
64

process requires the use of high mercury input. At most, it is merely cheaper for these 

kilns to continue using such input.

 Although EPA stated that [t]he concurring opinion in Brick MACT supports 

subcategorization in situations involving sources’ dependence on high-HAP raw 

materials to avoid situations where a level of performance achieved by some sources 

proves unachievable by other sources even after application of best technological 

controls, viewing such sources as of a different type than others in the source category 

(74 FR 21148 and Sierra Club v. EPA, 479 F.3d 875, 884-885, D.C. Cir. 2007, and 74 FR 

21140 [concurring opinion may provide a way out of the situation where the floor 

standards are achieved for some sources, but the same floors cannot be achieved for 

other sources due to differences in local raw materials whose use is essential]), those 

statements are no more than dicta in a concurring opinion without precedential value or 

authority. 

 EPA itself states subcategorizing by control device ... is not permissible, 74 FR 21145. 

As the CAA and D.C. Circuit precedent both make clear, the best performing sources are 

those with the lowest emission levels, regardless of whether those emission levels are 

achieved through the use of end-of-stack control technology or the use of cleaner fuels or 

raw materials. Sierra Club (479 F.3d 879-880). Because there is no relevant distinction 

for floor purposes between controlling emissions with an end-of-stack control device and 

controlling them through the use of cleaner fuels and raw materials, setting separate and 

more lenient standards for sources with high mercury limestone is just as impermissible 

as setting such standards for sources with ineffective or outdated control technology

would be.

Commenter 2911 stated that setting separate standards for kilns that use high mercury limestone 

would be arbitrary and capricious. Nothing in the CAA suggests that standards have to be 

achievable through the use of any particular control technology or through control technology in 

general. Creating a separate subcategory would create a perverse incentive for other kilns to find 

high mercury limestone so as to avail themselves of the same effective exemption from mercury

emission standards.

Commenter 2842 states that the decision not to subcategorize is fully consistent with the 

language in §112 for setting emission standards. Congress left the decision of whether to 

subcategorize based on class, type, and size of source entirely to the Agency’s discretion. Based 

on the record before it, the Agency reasonably concluded that the mercury emissions data do not 

readily support a subcategorization approach. The commenter’s further argued that: 

 EPA’s technical determination is worthy of deference. See Natural Resources Defense 

Council, Inc. v. EPA, 489 F.3d 1364, 1375 (D.C. Cir. 2007) (rejecting industry challenge 

to EPA decision not to subcategorize in light of the technical nature of the determination 

and the agency’s reasoned explanation).

 The argument advanced by certain industry representatives that subcategorization is 

required because some kilns with high levels of mercury in their feedstocks will not be 

able to achieve the standards in a cost effective manner finds no support in the statute. 

The D.C. Circuit has held that EPA must account for raw material HAP contributions in 

establishing MACT floors, and the fact that raw materials may be proprietary or 
65

otherwise not obtainable category-wide does not relieve EPA of that obligation. 74 FR at 

21148 (citing Sierra Club v. EPA, 479 F.3d at 882-83).

 Section 112 does not allow EPA to consider costs in establishing the MACT floor for 

HAPs such as mercury. NRDC v. EPA, 489 F.3d at 1375; see Sierra Club v. EPA, 479 

F.3d 875 (D.C. Cir. 2007). Congress envisioned that the establishment of the MACT 

floor would be a technical determination, not an economic one. See Sierra Club v. EPA, 

479 F.3d at 875 (rejecting argument that in establishing MACT floors based on what best 

performing sources have achieved, EPA may redefine best performing to mean those 

sources with emission levels that are achievable by all sources). 

 Judge Williams in the Sierra Club case noted, there is not necessarily any guarantee, 

even with suitable subcategorization, [that] every source will be able to achieve 

standards that meet a lawful application of §112(d)(3) to reasonably defined 

subcategories. 479 F.3d at 885.

Response: Because EPA is choosing not to exercise its discretion to create a subcategory for 

high mercury emitters with high mercury limestone quarries, it is unnecessary to respond to these 

comments.

Comment: Several commenters (2845, 2863, and 2916) stated that case law under the CAA 

§111 New Source Performance Standards (NSPS) made it clear that EPA may establish 

subcategories that are essentially based on a pollutant concentration in an input to the process. In 

its coal-fired power plant NSPS, EPA essentially distinguished between sources based on the 

concentration of a pollutant in an input – the sulfur concentration in the coal. The D.C. Circuit 

upheld EPA’s approach, holding that it had considerable latitude in differentiating between 

source types. Sierra Club v. Costle (657 F.2d 298, 318-319, D.C. Cir. 1981). The power plant 

NSPS required greater sulfur dioxide removal efficiency for sources with a higher concentration 

of sulfur dioxide emissions than for sources with a lower concentration in the emissions. When 

challenged, the D.C. Circuit quoted the §111(b)(2) language on how EPA is authorized to 

distinguish among classes, types, and sizes of sources, and concluded that [c]ertainly the text of 

the statute nowhere forbids a distinction based on sulfur content. 

Examples cited by the commenters of other MACT standards using subcategorization by

pollution concentration in raw materials are:

 Proposed National Emissions Standards for Hazardous Air Pollutants for Refractory

Products Manufacturing, 67 FR 42108, 42110, and 42119 (June 20, 2002);

 Proposed National Emissions Standards for Hazardous Air Pollutants for Plastic Parts 

and Products, 67 FR 72276 and 72288 (December 4, 2002); and

 Proposed National Emissions Standards for Hazardous Air Pollutants for Chemical 

Manufacturing, 73 FR 58352 and 58365 (Oct. 6, 2008). 

Commenter 2845 stated that EPA should establish two subcategories for mercury based on the 

concentration of mercury in the limestone, and should set beyond-the floor standards for the 

high-mercury limestone kilns requiring a 75 percent system removal efficiency. EPA’s Figure 1 

and Table 3 of the proposal preamble clearly show two outliers with mercury concentrations that 

far exceed those of any other sources in the database. 
66

Commenter 2845 stated that as EPA further notes in the preamble, [The Ash Grove Durkee kiln] 

has voluntarily entered into an enforceable agreement to install activated carbon (the best 

control technology currently available so far as is known) to control its mercury 

emissions...Closure of this kiln and possibly other high mercury emitting kilns is a possible 

consequence of a single standard without subcategories. The same would be true for other kilns 

not in EPA’s database that are similarly situated. This would be a result that Congress clearly did 

not intend. As the House Report for the 1990 CAA Amendments states, MACT is not intended to 

require unsafe control measures, or to drive sources to the brink of shutdown. House Rep. No. 

101-490, at 328 (1990).

Commenter 2863 stated that based on EPA’s data, a separate subcategory is appropriate for 

sources with greater than or equal to 225 ppb mercury in their limestone as these sources form a 

different type and class of source from the other category members and is supported by the 

courts. As Judge Williams noted in his concurrence in Sierra Club v. Envtl. Prot. Agency, 479 

F.3d 875, 885 (D.C. Cir. 2007) (Brick MACT), one legitimate basis for creating additional 

subcategories must be the interest in keeping the relation between ‘achieved’ and ‘achievable’ in 

accord with common sense and the reasonable meaning of the statute. Creating a ≥225 ppb 

subcategory also is consistent with the legislative history of the CAA. When 112(d) standards 

were developed, the possibility of requiring substitution of cleaner ore stocks was considered. In 

the Conference Committee report, Congress stated that the Administrator shall not consider the 

substitution of, or other changes in, metal- or mineral-bearing raw materials that are being used 

as feedstocks or material inputs... Conference Committee Explanatory Statement.

Response: Because EPA is choosing not to exercise its discretion to create a subcategory for 

high mercury emitters with high mercury limestone quarries, it is unnecessary to respond to these 

comments.

Best performers

Comment: One commenter (2911) stated that the holding that best performers are those with the 

lowest emission levels is binding precedent on the plain meaning of the CAA, and it reflects 

repeated holdings of the D.C. Circuit to the same effect. To attempt to rank cement kilns by

control efficiency would not only contravene the CAA but set bad policy and dangerous agency

precedent. 

Response: EPA is choosing in this rule to rank best performers based on emission levels (as 

normalized, for Hg and PM), and believes that this is a reasonable and permissible approach for 

this rule.

2.5.2 Adequacy of Floor Determinations (Existing and New)

Overly lenient standards

Comment: Several commenters (2144, 2867, and 2879) stated that EPA’s analysis of the floor 

resulted in overly lenient standards. They stated that EPA should conduct simulations such as 

Monte Carlo and use other statistical tools to handle truncated distributions. The commenter 

notes that the proposed emission standard is greater than the 30-day characteristics of any of the 

best performing 12 percent of the surveyed kilns, resulting in a standard less stringent than the 
67

highest emitter among the best performing kilns rather than equal to or more stringent than the 

average emissions from the best performing 12 percent. Commenter 2879 provided examples of 

alternative statistical analysis of data that could be used to more rigorously determine the 

expected average of the best performing 12 percent.

Commenter 2867 made the following recommendations:

 Lower the proposed emission standard for existing kilns towards the simple statistical 

average of 27.4 lb/MM tons of clinker consistent with the plain reading of the law 

(average of best 12%) and leave the proposed value for new kilns unchanged at 14 

lb/MM tons feed (23.1 lb/ton clinker).

 Resist attempts by industry advocates to introduce new variability schemes in the 

determination of the final mercury standard.

 Any subcategorization (if allowed at all) for the purposes of the mercury limit should be 

in terms of time to achieve the standard and not the magnitude of the standard.

Response: Monte Carlo simulation or bootstrap simulation has been used to account for different 

types of uncertainties. The suggestion by the commenters follows this recent tendency to use 

simulation techniques to account for uncertainties in the data. However, for this rule, we decided 

to use the Student’s t-test, which is called for when you have only a relatively small, random 

sample of emissions data available for analysis. EPA is not adopting any subcategories in this 

rule.

Analysis of variability

Comment: Many commenters (2830, 2836, 2841, 2845, 2858, 2859, 2863, 2864, 2874, and 

2889) stated that the limited data used by EPA in setting the proposed mercury limit does not 

adequately reflect the significant variability in mercury emissions and EPA’s MACT floor 

analysis resulted in overly stringent limits. They recommended that EPA re-evaluate the data 

upon which the mercury standard for existing kilns was derived, and use different statistical 

analyses. 

Commenters 2830 and 2845 recommended using the statistical analysis used to set other 

NESHAP standards and programs under the CWA and the Resource Conservation and Recovery

Act (RCRA), which gives more accurate consideration of the variability in certain data sets. 

Commenters 2859 and 2864 support commenter 2845’s discussion of an alternative approach to 

analyzing the mercury data set used to determine the MACT floor. This commenter 

recommended using the UTL method to account for variability within the data set. The 

commenter’s UTL analysis of the mercury data resulted in an alternative mercury floor no less 

than 51.5 lbs/million tons of kiln feed for existing units and 14.2 lbs/million tons of kiln feed for 

new units. The commenter included detailed statistical analysis in support of their recommended 

limits. Commenter 2830 stated that the appropriate NESHAP standard for mercury should be 

between 43 lbs/million tons of clinker and 50 lbs/million tons of clinker for existing units. 

Commenters 2844, 2845, 2859, 2863, 2874, and 2889 stated that by using data collection over 

only 30 days, EPA has failed to capture the variability of the performance of those units. The 
68

commenters recommend collecting data over a wide range of operating conditions or developing 

alternative operating scenarios and the effects of alternative operating conditions can be 

determined via mass balance calculations (by changing the mix of materials and the mercury 

contents of those materials). Commenters 2858, 2859, and 2874 noted that causes of variability

such as variations in raw materials and fuels, wasting of varying amounts of kiln dust, and the 

production of different products were not adequately addressed in the data collection process. 

Commenter 2863 provided three years of results of analysis to highlight the variability of the 

mercury content of their feed limestone, which all comes from the same quarry and mineral 

formation. Limestone mercury concentrations ranged from 424 ppb to 1740 ppb. 

Commenters 2845, 2863, and 2864 noted that EPA considered only 30-day samples of emissions

data from various units in setting the mercury standards, and in addition, EPA considered a kiln 

that was producing a product during the 30-day data collection period that resulted in an 

emission profile that was not representative of normal operations of the kiln. If this kiln’s 

production of this product is weighted based on the kiln’s actual production, its emissions 

increase and it is no longer one of the best performing sources. 

Commenter 2845 conducted a site-specific variability analysis that included interviewing plant 

personnel of the 11 MACT floor kilns. Independently from the 30-day emissions data collected 

by EPA, the analysis focused on normal and foreseeable operations of the kilns used by EPA to 

propose the mercury standard. Each of the kilns in EPA’s proposed MACT floor was reviewed 

for variations in products, raw materials, fuels, operating conditions, and the effectiveness of 

pollution controls. The commenter also considered EPA data regarding mercury content of fuels 

that are used or could reasonably be used by the facilities in the MACT floor. The analysis 

demonstrated that foreseeable circumstances at units in the MACT floor justify an existing 

source mercury standard of 106 lbs/million tons of kiln feed and 36 lbs/million tons of kiln feed 

for new sources. The commenter provided detailed supporting information in an appendix. 

Commenter 2841 disagrees with EPA’s approach of mass balance tracking the feed materials and 

assuming that all mercury entering the kiln system would be emitted from the stack. Using a 

mass balance for such a significant standard will result in significant costs with the real 

possibility of little or no environmental benefit. It would be far more appropriate to allow time 

for facilities collect more data and further to allow each facility to determine the speciation of 

this naturally occurring mercury in their limestone quarries and other sources of raw materials. It 

may be appropriate to subcategorize by species of mercury or other similar approaches, if 

enough data is collected.

Response: We carefully reviewed the comments on the analysis of variability. (See the docket 

for the detailed review of these comments.) It is clear that the commenters mistakenly believed 

that EPA intended to set the MACT floor using the 99th percentile. The 99th percentile of a data 

set, is the data value at which 99 percent of the data will be found. They also state that because 

EPA was using a modified UPL, that EPA was calculating a future probability rather than the 

99th percentile for the actual data, which they wrongly considered inconsistent with the intention 

of the CAA. They stated that because of the small size of the data sets for mercury, PM, and HCl 

that EPA’s choice of the 99th percentile was faulty and they recommended that an upper 

tolerance limit (UTL) for smaller data sets be used. They state that the UTL does generate the 

99th percentile. For larger data sets, such as the THC data, the actual 99th percentile can be used. 
69

UTL is not for prediction purposes, so it won’t say what the data will be in the future. The 

prediction properties are a characteristic of the UPL. Both UPL and UTL are based on the 

present data, but UPL take into account the future observations variability. If the idea is to obtain 

an upper bound that is greater than the 99 percentile, then the UTL works. The UTL will 

generally be a larger number than the 99 percentile. This was not EPA’s intention but we realize 

that our explanation at proposal was not sufficiently clear. Based on comments and our 

reanalysis of our methods, we realized that there was an error in the UPL equation at proposal 

that has been corrected.

In response to comments, we re-evaluated the statistical analysis used for the proposed rule and 

made changes to improve it. The changes we made and why are discussed in the preamble to the 

final rule and in supporting documentation in the docket and include why we continue to believe 

the use of the UPL is the most appropriate statistical approach, how we accounted for variability

(including intra-quarry variability), and other changes to the analysis since proposal. We disagree 

with the commenters who said 30 days of data are insufficient, and we continue to believe that 

the 30 data points provided from 30 days of sampling of all kiln inputs for 89 kilns is a robust 

sample of the population of cement kilns and adequate to characterize the variability encountered 

at each individual kiln, especially as supplemented with the estimates of intra-quarry variability.

The top performing kilns used raw materials and fuels from different sources, wasted varying 

amounts of cement kiln dust, and included different types of kilns operating under various 

operating conditions. Moreover, as discussed in the preamble, we continued to refine our 

analysis and revised it to further refine estimates of intra-quarry variability. We also corrected 

the case cited by the commenter for the kiln that had an emissions profile that was not 

representative of its normal product mix, and this kiln is no longer in the top performing 12 

percent.

We have also addressed in the preamble to the final rule the commenter’s suggestion that, under 

“foreseeable circumstances,” the MACT floor for mercury would be higher. In addition, we note 

here that the 30-day rolling average form of the mercury standard allows an owner or operator to 

detect trends in increasing mercury emissions over days and to take corrective actions, whether 

by improving mercury emission control devices or changing certain kiln inputs, before the limit 

is necessarily exceeded. The 30-day rolling average provides much more flexibility in dealing 

with foreseeable events than would a shorter term averaging period (such as an hourly or daily 

average).

Our use of mass balance tracking of mercury to develop the mercury emission limit is reasonable 

because it is based on the knowledge that, in the absence of a mercury emission control device, 

the mercury in the kiln’s inputs is emitted. We see no reason why the use of a mass balance 

approach rather than collecting data on speciated mercury emissions (as the commenter suggests) 

would result in significant costs with little or no environmental benefit, nor did the commenter 

provide information that would support such a claim. There is also no reasoning or information 

presented that would indicate that it might have been appropriate to subcategorize by species of 

mercury or other similar approach, and we do not believe such approaches are warranted.
70

Use of subcategories

Comment: Many commenters (2842, 2893, 2928, 2984, 2987, 2989, 2994, 3001, 3005, 3023, 

3030, 3034, 3038, 3045, 3052, 3056, 3057, 3059, 3061, 3062, 3063, 3065, 3073, 3074, 3077, 

3098, 3101, 3104, 3105, 3107, 3110, 3125, 3128, 3130, 3132, 3226, and 3227) agreed with 

EPA’s decision to not create subcategories in establishing mercury standards. 

Commenter 2928 stated that because of the current effectiveness of mercury controls available to 

cement plants, as well as a variety of new control options available by the 2013 deadline these 

new proposed emission standards set, it is not necessary to allow for subcategories for cement 

plants that claim the mercury content of their limestone is to blame for their emissions. 

Commenter 2893 stated that subcategorization based on limestone composition unfairly

depreciates the value of cleaner limestone sources and undermines the intent of the proposed 

rule.

Commenter 2999 disagreed with the proposed subcategorization of plants based on their 

limestone mercury levels, but sees the value of a temporary subcategory for existing cement 

plants to allow those plants more time to comply with mercury emissions rules if they have 

recently made substantial investments to lower mercury emissions using a reasonably close to 

state of the art technology.

Commenter 2828 stated that there are multiple options for the ultra-high mercury emitting kilns:

 Use of limestone with lower mercury levels, including transport of limestone from 

sources within a 5 to 10 mile radius.

 Installation of serial pollution control systems.

 The combination of fuel selection (more natural gas, less coal), coal and limestone 

washing, and multiple mercury control systems. The mercury control systems could 

include ACI injection, followed by a baghouse, and then if needed, another 

ACI/baghouse system.

Several commenters (2144, 2840, and 2845) argued for the creation of subcategories. 

Commenter 2144 stated that EPA should create an interim hyper mercury limestone subcategory

only for the two kilns that exhibited estimated emissions greater than 1,000 lb/yr and require the 

least stringent of 90 percent Mercury removal and the final mercury standard. The kilns in the 

hyper Mercury limestone category would ultimately meet the final emissions standard and phase 

out the alternative 90 percent removal requirement.

Commenter 2840 suggested that for a subcategory of cement plants with elevated mercury levels 

in their limestone, EPA could require employment of maximum achievable control technology to 

reduce mercury emissions and limit the use of offsite materials containing elevated levels of 

mercury.

Commenter 2845 stated that EPA should subcategorize emission sources by mercury

concentration in the limestone to address variability and ability to comply issues. Given that 

cement kilns must use limestone from a nearby quarry to produce clinker, they should be seen as 
71

essentially co-joined with that quarry for purposes of subcategorization. Mercury emissions 

characteristics are based in large part on available limestone and it is unreasonable and arbitrary

not to establish subcategories where technical differences between different types or classes of 

cement kilns result in different emissions characteristics.

Commenters 2844, 2845, 2863, 2900, and 2917 stated that EPA should provide a new 

subcategory for kilns that have a high concentration of mercury or other HAP in the limestone 

quarries servicing those kilns. As recognized in EPA’s proposal, these kilns likely would be 

unable to meet the proposed standards even after installing state-of-the-art controls. While there 

are a limited number of facilities in EPA’s data set with this issue, commenter 2845 stated that 

there may be other similarly situated kilns throughout the United States, not reflected in the data 

set. Commenters 2844, 2845, and 2900 proposed a subcategory that results in a high MACT 

floor emission rate and then proposed that EPA use beyond-the-floor consideration to apply 

state-of-the-art controls on those facilities. For sources in the proposed subcategory for units with 

high mercury concentrations in the limestone, Commenter 2845 proposed a 75 percent removal 

standard as the beyond-the-floor limit, which reflects the best percent removal of mercury that 

may be obtained through technology at those particular sources.

Commenters 2298, 2483, 2502, 2503, 2506, 2507, 2651, 2653, 2654, 2660, 2661, 2667, 2670, 

2671, 2672, 2676, 2811, 2812, 2813, 2830, 2832, 2833, 2840, 2841, 2845, 2863, 2874, 2886, 

2900, 2903, 2904, 2973, 2974, 2979, 2982, 2983, 2996, 2997, 3012, 3013, 3014, 3016, 3031, 

3036, 3039, 3046, 3052, 3058, 3066, 3071, 3075, 3079, 3081, 3083, 3085, 3090, 3091, 3093, 

3095, 3096, 3097, 3100, 3102, 3111, 3114, 3115, 3116, 3119, 3120, 3122, 3123, 3125, 3126, 

3127, 3129, 3134, 3135, 3141, 3144, 3147, 3153, 3155, 3157, 3158, 3159, 3166, 3174, 3175, 

3177, 3178, 3180, 3204, 3208, 3209, 3210, 3211, 3213, 3217, 3218, and 3219 stated that EPA 

should provide a new subcategory for kilns that have a high concentration of mercury in the 

limestone quarries servicing those kilns. As specifically recognized in EPA’s proposal, these 

kilns likely would be unable to meet the proposed standards even after installing state-of-the-art 

controls. 

Commenter 2863 recommended the following actions on subcategorization for purposes of the 

mercury standard:

 No use of fly ash as an additive in the raw feed;

 Implementation of dust shuttling to the maximum extent possible without impacting 

product quality;

 Implementation of a Mercury Minimization Plan to minimize mercury in the raw 

materials imported from off-site; and

 Implementation of a Control Enhancement Action Plan.

Response: The EPA reasons for declining to establish a subcategory for high mercury emitting 

kilns with high mercury levels in their quarried limestone are set out in the preamble to the final 

rule. We also examined other actions on developing subcategories suggested by Commenter 

2863 and concluded that although these actions might help to reduce mercury emissions at a 

given kiln, they do not provide a basis for subcategorization, nor could they be used to represent 

MACT. We have concluded that subcategorization for mercury emissions, which was the subject 
72

of the comments provided above, is not necessary or warranted because the mercury emission 

limits can be met with the application of mercury emission controls and/or other practices, such 

as those that reduce the amount of mercury in inputs to the kiln. 

We also disagree with a commenter’s statement that a 75 percent removal standard should be the 

beyond-the-floor limit because ACI technology for mercury will achieve higher removal levels 

than 75 percent, and for some kilns with high mercury inputs, a removal of only 75 percent 

would not even represent the MACT floor. We also disagree with the development of “interim” 

standards and note that the CAA provides the allowable schedule for compliance for existing 

sources in section 112(i)(3) (with some discretion by EPA and the permitting authority when 

extra time is needed to install emission controls).

Pounds of mercury per million tons of feed includes fuel in denominator

Comment: One commenter (2849) stated that EPA incorrectly calculated the conversion from 

pounds per million tons of feed to pounds per million tons of clinker when it developed its 

mercury floor levels. When EPA computed its mercury balance for each of the 89 kilns it used in 

the mercury MACT floor calculation, it used total mercury inputs from raw materials and fuels, 

then subtracted out the mercury output from kiln dust not recirculated to the kiln, to arrive at a 

calculated mercury emission (in pounds). It then divided these pounds of mercury emissions by

the total quantity of raw material plus fuels inputs to arrive at emission units that were entitled 

pounds of mercury per million tons of feed. In fact, a more correct title for these emission units 

should have been pounds of mercury per million tons of feed plus fuel.

Response: The commenter’s characterization of EPA’s approach to calculating mercury

emissions per ton of clinker is partially correct with the exception that we did not, as the 

commenter states, include the quantity of fuel along with the quantity of feed materials in 

calculating mercury emissions in pounds per million tons of clinker. In response to the comment, 

we reviewed the approach used as well as the data to confirm that fuel materials were correctly 

categorized and not included in the sum of raw materials for each kiln. 

To calculate mercury emissions per ton of clinker, all materials reported in the responses to 

EPA’s May 8, 2007 information collection requests (ICR) were entered into an Access database. 

All materials (feed and fuel) were classified in a raw materials table and through database 

queries into one of the following categories:

Limestone

Shale

Clay

Fly ash/bottom ash

Sand

Iron

Other raw materials

Coal/coke/fossil fuel

Tires/TDF

Wasted CKD

To be considered as a feed material, the reported raw materials for each kiln could not also be in 

a fuel or CKD category. Mercury emissions per million tons of feed were then converted to 

emissions per million tons of clinker by multiplying by the conversion factor of 1.65 tons of feed 

per ton of clinker. Although EPA’s approach for calculating mercury emissions per ton of clinker 

was designed to exclude fuel in the denominator, it is possible that a minor, uncommon fuel 
73

material used at a kiln was incorrectly classified as a feed material. However, coal, coke, other 

fossil fuels and tire derived fuel constituted nearly all of the fuel for most kilns and a 

misclassification of a minor fuel material as feed, or vice versa, would not have any significant 

effect on a kiln’s final emission rate.

Data suggest a 12-month average standard

Comment: One commenter (2864) stated that although EPA collected 30 days of mercury input 

data for 89 kilns, the Agency also collected annual data on the mass inputs and the amount of 

material collected in the PM control device (or alkali PM control device) that is wasted rather 

than returned to the kiln. The annual average data were used to calculate the mass-balance 

mercury emissions, which were then used to establish the mercury floor. The commenter stated 

that this is an annual mercury emission rate and EPA should establish a rolling 12-month average 

mercury MACT standard.

Response: As stated previously, EPA’s legal obligation in establishing MACT floors is to 

reasonably estimate the average performance achieved by the best performing 12 percent of best 

performing sources, or for new sources, the performance of the best controlled similar source.

The statute does not speak to the issue of permissible averaging times in constructing standards, 

so it may be that in factually appropriate cases, a choice of averaging time to account for best 

performing sources’ variability could be legitimate. However, automatic (i.e., a priori) 

determinations to adopt long-term averages for any type of data set regardless of circumstances 

of sources’ performance and robustness of the data set, would go too far. We chose a 30-day

averaging period for the mercury emission limit. The use of a 30 day average (as opposed to 

hourly or daily averages) tends to reduce variability, and also best reflects the nature of the data 

from which the floor was derived and assures that several operating cycles of raw mill on and off 

are included in each average. The mercury limit is based on a 30-day averaging period to be 

consistent with the averaging periods for other regulated kiln pollutants, and adequately allows 

additional operating flexibility to meet the limit. Finally, EPA is setting the compliance period 

using 30-day averaging periods for enforcement reasons in that EPA can periodically determine 

compliance with the emission limits and avoid long periods in which sources may be emitting at 

unacceptably high levels.

Provide alternative removal efficiency standard

Comment: Several commenters (2845 and 2874) stated that EPA should set an industry-wide 

MACT floor set on the basis of percent removal, or system removal efficiency (SRE) to be used 

as an alternative to the currently proposed mass-rate based emission limit.

Response: For the reasons stated in the preamble to the final rule (and comment responses 

therein), EPA is not expressing standards, or determining MACT floor, on a per cent reduction 

basis. No commenter provided a convincing response to how such an approach, in this rule, 

properly accounts for the role of HAP in kiln inputs. Nor did commenters address how such a 

standard could even be constructed for mercury, where there is essentially no system removal 

because kilns are uncontrolled and mercury volatilizes.
74

2.5.3 Beyond the Floor Determinations

Comment: Several commenters (2845 and 2863) stated that EPA correctly explains that if it did 

not subcategorize based on mercury concentration in the limestone, it would not be appropriate 

to establish a beyond-the-floor standard for mercury for either new or existing sources. Doing so 

would not be cost-effective. As a result of the much higher mercury emissions from kilns in a 

subcategory of sources with high mercury concentration in the limestone; however, a beyondthe-floor standard may be appropriate. The commenter states that such a beyond-the-floor 

standard should be expressed in terms of system removal efficiency (i.e., percentage reduction of 

mercury entering the kiln in the raw materials and fuel). The commenter further states that a 

75 percent system removal efficiency for mercury would represent a stringent beyond the floor 

standard for both new and existing sources that nevertheless could be achieved through the use 

of ACI, the best mercury control available.

Commenter 2898 recommended that EPA address fuel-switching as a beyond the floor option. 

EPA should explain what site-specific circumstances might influence the substitution of lowmercury materials and fuels for some facilities, and why the practice could not be applied 

uniformly on a national basis. The commenter suggests that EPA fully explore non-technology

emission reduction options in the beyond the floor discussion, including fuel-switching.

Response: EPA agrees that a beyond-the-floor standard is not appropriate for mercury given the 

decision not to subcategorize. See preamble for response to comment to consider fuel switching.

2.5.4 Compliance Assurance

Form of the Standard

Comment: Commenter 2879 stated that CEMS readings and clinker production calculations can 

be unreliable. Rather than assuming that kiln operators can accurately determine the mercury 

emissions per million tons of clinker on a 30 day average basis, EPA should determine the 

mercury CEMS concentration that corresponds to the proposed 43 lb/MM ton clinker, or the 

appropriate value representing the average of the best performing 12%.

Commenter 2889 suggested that EPA conduct error analysis to evaluate the ability of a source to 

comply with the mercury monthly block average emission limit. To comply with the mercury

limit in the proposed amendments, a cement kiln operator will have to measure (1) the mercury

concentration in the gas stream, (2) the gas flow rate in the stack, and (3) the clinker production 

rate. These three sources of data will be combined to determine compliance with the monthly

block average limit. Considering the low emission rate in the proposed amendments, EPA should 

evaluate the inherent measurement error associated with these quite different measurements. 

Cement kilns could appear to be out of compliance simply because of slight unavoidable 

variability of the accuracy of the three measurements. This problem could be reduced slightly by 

simply applying a mercury concentration limit in the gas stream without any reference to the 

clinker production rate.

Response: Issues related to clinker measurement are addressed in the preamble to the final rule. 

Other facilities in the utility industry and the cement industry are currently measuring mercury

concentrations at and below these levels using a CEMS. 
75

Data supports mass balance approach

Comment: Several commenters (2844, 2845, 2855, 2859, and 2901) stated that EPA has 

provided no support for its assumption that the mass-balance data used to establish the mercury

MACT floors can be correlated to continuous emissions monitoring data to demonstrate 

compliance. The commenters stated that there is no basis for the Agency’s assumption that 

conservation of mass data calculations made for the cement industry correlate with the emission 

measurements that may be made in the future with mercury CEMS. 

Response: The mercury emission standard is based on a MACT floor of pounds of mercury

emissions per ton of clinker, adjusted for variability. We believe that the analysis described in 

the proposal notice and in the docket does support a correlation between the MACT floors and 

continuous monitoring data collected on a 30-day rolling average.

Comment: Commenter 2844 stated that CEMS will create compliance issues that are not related 

to emissions compliance; CEMS represent a very high added cost beyond any value; and EPA 

should adopt mercury limits that allow the use of mass balance calculations.

Commenters 2855 and 2874 stated that EPA should reconsider a sampling and analysis program 

involving kiln inputs as an acceptable option to CEMS for demonstrating compliance with a 

mercury standard. Commenter 2855 stated that this approach should be allowed because EPA 

relied on this approach to establish the mercury standards, and for low level mercury emitting 

facilities that can comply with the standards without add-on controls, the solid material sampling 

programs could be focused to optimize accuracy and minimize costs.

Commenter 2855 stated that facilities that control mercury emissions from cement kilns or 

kiln/in-line raw mills should be allowed to use solid or liquid material sampling and analysis to 

demonstrate mercury removal as an optional monitoring approach. Facilities that waste cement 

kiln dust (CKD) or implement dust management programs to minimize mercury emissions 

should be allowed to implement solid material sampling and analysis procedures to quantify the 

mass of mercury removed. The optimal sampling location and approach must be determined on a 

site-specific basis. Similarly, sources with add-on controls should be allowed to implement 

material sampling and analysis procedures to quantify the mass of mercury removed and subtract 

the documented mercury removed to determine compliance with mercury standards.

Commenter 2888 recommended that since the orientation of monovent kilns does not provide a 

means for a stack flow meter (there is no stack) or a CEM, these kilns should perform a mass 

balance of the material flows into and out of the process, for purposes of demonstrating 

compliance with the NESHAP mercury standard. 

Response: Mercury is a unique pollutant because the amount of mercury input to the system 

equals the amount of mercury output. In the absence of control devices, input equals output, and 

a material balance approach is feasible. However, the cost of collecting such data on a daily basis 

is comparable to the cost of a mercury monitoring system. In addition, in order to meet the 

mercury standards, many sources will install control devices. In order to conduct a material 

balance on this now more complicated system, we would have to determine a reliable control 

device efficiency value and require continuous monitoring of control device parameters. Given 
76

these costs and uncertainties, we conclude that continuous monitoring at the stack is the best 

method to determine compliance. As always, however, sources are allowed to request sourcespecific approval of alternative compliance methods under the part 63.7 General Provisions.

CEMS not demonstrated in cement manufacturing

Comment: Many commenters (2830, 2845, 2846, 2855, 2858, 2859, 2879, 2887, and 2890) 

stated that CEMS are not a proven technology and should not be required to determine 

compliance. 

Commenters 2588, 2844, 2845, 2846, 2858, and 2890 stated that EPA has no data showing that 

mercury CEMS are feasible on cement kilns and that emissions from cement kilns will likely be 

outside of the range of the current CEMS technology. The commenters stated that EPA must 

evaluate mercury CEMS through long-term field trials at cement plants in accordance with the 

proposed performance specifications and quality assurance procedures before imposing this 

regulatory requirement. The commenters proposed a mass-balance approach for monitoring, 

which is accurate and was used by EPA in setting the mercury standard.

Commenter 2855 stated that mercury sorbent trap monitoring systems have not been evaluated 

through long term field trials at cement plants in the United States (U.S.) in accordance with the 

proposed performance specifications and quality assurance procedures, so the reliability and 

performance of these measurement systems and the adequacy of the technical specifications 

cannot be determined. 

Commenters 2855 and 2900 disagreed with EPA’s interpretation of the operating experience 

with mercury CEMS in Germany. The commenters stated that mercury CEMS are inaccurate and 

difficult to maintain. Further, mercury CEMS operating in Germany are subject to monitoring 

regulations that are different than the U.S. regulations and are used in a different regulatory

context than that proposed by EPA. The monitors used in Germany, or those available from other 

European or Asian manufacturers were not able to demonstrate acceptable performance in the 

Electric Power Research Institute (EPRI) Trimble County Mercury CEMS study. 

Commenter 2855 stated that there is no legitimate technical basis on which to establish detailed 

performance specifications or quality assurance (QA) requirements for these CEMS. There is no 

legitimate technical basis to conclude that these CEMS could meet such requirements over any 

extended period when installed and operated at a cement plant. The commenter recommended 

that EPA evaluate the performance of mercury CEMS at cement kiln systems and acquire the 

information necessary to serve as the basis for technical specifications and requirements. After 

such information is available and analyzed, EPA should re-propose appropriate and 

demonstrated performance specifications and quality assurance procedures for mercury CEMS to 

monitor kiln and kiln/in-line raw mill mercury emissions. 

Commenter 2855 disagreed with EPA’s interpretation that mercury CEMS can be applied to the 

cement industry based on successful use on utility boilers. The commenter evaluated the 

following issues:
77

 Number of Installations in the Utility Industry – there are 35 – 40 continuous mercury

monitors (CMMs) installed and certified to date (not yet with a NIST traceable 

calibration source).

 NIST Certification – In mercury CEM certification requirements outlined in Performance 

Specification (PS)-12A, it states that all calibration and span gases must be NIST 

certified. The draft protocols were just released by NIST in July 2009. The major vendors 

of mercury CEM are just now advertising NIST-certified calibration sources. Therefore, 

none of the mercury CEMs that have been previously installed are certified. NIST does 

not currently directly certify oxidized mercury calibrations. The Interim EPA Traceability 

Protocols now in place provide for certification of evaporative generators by certification 

of the individual components of the calibrator. Therefore, the language used in Section 

7.0 that refers to a NIST trace oxidized mercury calibrator needs to be clarified or 

changed.

 Difficulties Encountered in the Utility Industry – The commenter gave examples of 

power plants’ difficulties with mercury CEMS.

 Installation on Wet Stacks – Installing a mercury CEMS on a wet stack can result in 

problems: plugging, corrosion, and buildup of solids. Although wet scrubbers are not 

currently common in the cement industry, under the proposed rule, they may be required 

to a greater extent, and many of these same problems with mercury CEMs potentially

could occur for the cement industry as well.

 Data Output Requirements – There is no need for dry basis measurements under the 

proposed rule and the language in either Subpart LLL should be included to provide an 

exemption from this requirement for cement plants or PS-12A should be revised. This 

language needs to be clarified by EPA.

 Cost – The commenter provided information about CEMS costs, estimating that if 

mercury CEMS were installed on all non-waste-burning U.S. cement facilities, the total 

capital costs would be approximately $45 million, with annual operating costs being 

about $25 million. 

Commenter 2901 stated that CEMS should not be used as a compliance method for cement 

plants for the following reasons:

 EPA reported in 1997 on an experiment where CEMS were installed on a cement kiln 

burning hazardous waste. The Agency found substantial problems regarding mercury

CEMS measurement accuracy and precision, deciding not to require Mercury CEMS at 

cement plants. The commenter stated that the primary issue is whether there is a NIST 

traceable standard that can be used to calibrate the unit. Because compliance is based on 

the production rate and using a 30-day average, it is difficult to know what range to 

calibrate these units.

 The reliability of CEMS on cement kiln stacks has not been demonstrated in the U.S., 

where standards and requirements are different. Demonstrations in the U.S. at coal-fired 

power plants have different conditions than those at cement kilns. 

 There is no legal imperative for EPA to require CEMS. Under the CAA, EPA’s 

monitoring requirements must provide a reasonable assurance of compliance with 
78

emission standards Sierra Club v. EPA, 353 F.3d 976, 990-991 (DC Cir 2004) (Copper 

Smelters) citing Natural Res. Def. Council, Inc. v. EPA, 194 F.3d 130, 136 (D.C. Cir 

1999). 

Response: See response in preamble.

Comment: Commenter 2890 stated that CEMS represent a requirement that is beyond the floor.

Response: Assuming the argument that measuring methodology can be considered to be part of 

a standard, the use of CEMs to measure the mercury standard does not make the standard more 

stringent. The mercury standard was developed on the basis of 30-day data samples, and is 

measured over the same duration. The standard was also developed on a mass balance basis 

whereby essentially all input mercury was considered to be emitted (except for the few kilns 

equipped with wet scrubbers). This is essentially a worst case assumption (attributing no removal 

to baghouses, for example). Given that the standard is measured over the identical duration as 

was the underlying data, and that actual emissions are measured so that kilns are no longer 

presumed to emit all inputted mercury, we repeat that use of a CEM does not make the standard 

more stringent and thereby constitute a beyond-the-floor standard.

Comment: Several commenters (2155, 2867, 2891, 2894, and 2898) supported EPA’s decision 

to require mercury compliance monitoring using CEMS. 

Commenter 2867 reports that their own inquiry to the German Federal Environment Agency, 

(Umweltbundesamt [UBA]) regarding the mercury-CEMS features of the proposed cement 

MACT rule, which found the mercury CEMS QA suitable to ensure quality measurements. 

According to the commenter, UBA has the most experience in the world among environmental 

agencies in the field of mercury-CEMS including the cement industry. The commenter also cited 

the experience of the Ash Grove Durkee, Oregon facility. The commenter noted that the results 

for this facility presented at the 2008 Air and Waste Management Association (AWMA) 

Conference in Oregon showed that the mercury-CEMS registered the same average stack 

mercury emissions reading (0.027 g/s) when the raw mill was on as the average value of the 

Methods 324 and OH. The commenter stated that this indicates that mercury-CEMS are feasible, 

precise and accurate compared with the conventional in-stack sampling methods at low and at 

elevated emission rates.

Commenter 2894 stated that as manufacturer of mercury monitoring instrumentation, they are in 

the process of installing mercury CEMS on U.S.-based cement kilns. There are no technical 

obstacles to the use of mercury CEMS in this type of environment.

Response: We agree with these commenters that mercury CEMS should be used for compliance 

monitoring.

Wet vs. Dry Concentration Format for CEMS

Comment: One commenter (2894) stated that in order to maximize accuracy in mercury mass 

emission calculations, mercury CEMs should report mercury concentrations as μg/m3(at 20 oC, 

760 mm mercury pressure) on a wet basis. No correction for O2, carbon dioxide (CO2) or any 

other gas should be performed. Stack flow rate should also be measured on a wet basis, in 
79

m

3

/min (at 20 oC, 760 mm mercury) at the same point in the process, with no correction for any 

diluent gas.

Commenter 2894 recommended calculating mercury emissions using a wet concentration and 

wet flow rate in equation 5 (Ref Eq. 5, page 21187, col 2) rather than the currently required dry

concentration and dry flow rate. A dry mercury concentration is not required to calculate mass 

emissions and would actually reduce the accuracy. In the event that a dry concentration is 

absolutely required, the rule should make it clear that the same (BWS) factor must be used to 

correct both the mercury concentration and the flow rate. This factor should be a calculated 

value; a moisture analyzer is not required since the two occurrences of the BWS factor cancel 

arithmetically. 

Commenter 2855 said that there is no need for dry basis measurements under the proposed rule, 

and the language in either Subpart LLL should be included to provide an exemption from this 

requirement for cement plants or PS-12A should be revised. This language needs to be clarified 

by EPA.

Response: We agree with the commenters that dry concentrations and flow measurements are 

not required to calculate mass emissions. It is important that the measurements are on the same 

basis, wet or dry, for the calculations. The equations have been modified and clarifying text 

added. We have revised to standard to state that dry measurements are not required.

Comment: One commenter (2837) recommended that the period for calibration drift check 

should be defined by system operator, rather than defining this period on the basis of any one of 

the available technologies. The commenter also recommended that EPA define how the operator 

is to demonstrate the validity of the operator-defined calibration check period.

Response: Requirements for calibration checks, including the frequency (once daily), are 

specified in Appendix F, Procedure 5. The procedures to be used are based on manufacturers’ 

recommendations.

Establish standard as CEM concentration

Comment: One commenter (2879) recommended that EPA should measure mercury emissions 

using a CEM, reconciling CO2 emissions with mass balance emissions and establishing the 

standard as a CEM concentration.

Response: Under the final testing and monitoring requirements, CEMS or sorbent trap monitors 

are required to continuously measure mercury emissions. See the preamble discussion under 

final testing and monitoring requirements for more information on EPA’s decision.

Emission limits are typically normalized to some type of production or raw material input value 

because this allows comparison (and ultimately the ability to set a single standard) for different 

sized facilities. As we noted at the NSPS proposal, the current NSPS and limits (and NESHAP 

limits before today’s amendments) for PM are expressed on a pound of PM per ton (lb/ton) of 

dry feed input format. See 73 FR at 34075-76. In this final NESHAP (and NSPS) we are 

adopting a new normalizing parameter of lb/ton of clinker – i.e., normalizing based on kiln 

output rather than input for both PM and mercury.
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EPA therefore proposed that all of the NSPS (for PM, NOx, and SO2) be normalized by ton of 

clinker produced, and later proposed the same parameter for the two standards in the NESHAP 

which are normalized, mercury and PM. 73 FR at 34076; 74 FR at 21140.

In the final NESHAP (and NSPS) we are therefore adopting a new normalizing parameter of 

lb/ton of clinker – i.e. normalizing based on kiln output rather than input – for mercury and PM 

in the NESHAP, and for PM, NOx, and SO2 in the NSPS.

See the preamble discussion under format of the normalized standards in the NESHAP and the 

NSPS, for more information on EPA’s decision.

All mercury phases should be monitored

Comment: One commenter (2638) stated that all phases of mercury should be monitored and PS 

12A and Procedure 5 should be rewritten to include total mercury. The commenter stated it is 

contrary to the intent of the CAA to set emission limits for only vapor phase mercury and 

requested that the EPA change its emission limit from one based on vapor phase mercury to one 

based on total mercury that includes both PM and vapor phases.

One commenter (2638) stated that all physical phases of all HAP metals, including mercury, 

need to be measured during SSM events. For example, if mercury is captured on powdered 

activated carbon, which in turn is captured on a fabric filter, the percentage of mercury in the PM 

fraction downstream of the fabric filter during malfunctions could and would be expected to be 

significant.

Commenter 2638 stated that total mercury monitoring can now be undertaken with proven 

methods, and will be consistent with Congress’ desire for the EPA to require enhanced 

monitoring where it is appropriate to assure continual compliance with emission limits. The 

commenter provided several reports describing alternative measurement methods.

Response: The mercury standard is based on total mercury data in the form of mercury inputs to 

the source. As part of this reconsideration tests were performed at five facilities with wet 

scrubbers. Testing was performed at the scrubber inlet and outlets. We believe tests at a wet 

scrubber outlet would represent a situation where particulate mercury would most likely be 

present due to the lower temperatures involved (below 200OF). On average the amounts of 

particulate mercury measured at both locations was below 1 percent. Given this fact, we believe 

that measurement of total mercury would add unnecessary expense and complexity to mercury

monitoring. However, sources are able to request approval for source-specific monitoring 

requirements from EPA under section 63.7 (f) of the General Provisions.

Measurement bias not considered in achievability of standard

Comment: One commenter (2855) stated that EPA did not consider the allowed measurement 

bias for mercury CEMS or sorbent tube monitoring programs on the achievability of the 

emission standards. 

Response: We disagree that either the mercury CEMS or the mercury test Method 30B include 

an inherent measurement bias. All measurement data are subject to some degree of variability
81

which would include measurement error (e.g., interference) and imprecision (e.g., measurement 

repeatability). The procedures in Performance Specification 12A promulgated with this rule 

account for both measurement error and imprecision in calculating the relative accuracy of the 

CEMS. Secondly, we believe that any inherent variability of data due to measurement 

imprecision is reasonably addressed in calculating the floor and emissions limits. The data used 

to establish the limits represent emissions tests from multiple facilities and we subjected the data 

to statistical procedures to account for variance.

Contradiction in performance test duration

Comment: One commenter (2855) stated that §63.1349(b)(5)(i) specifies a mercury

performance test duration of a calendar month, which contradicts the averaging period of the 

proposed emission standard of a 30-day rolling average. 

Response: We do not consider this a contradiction because both monitoring periods have 

different purposes. The performance test for a calendar month is to ensure that the control device 

and the CEMS are both working correctly. The 30-day rolling average is the compliance 

demonstration period. We are proposing additional clarifications such as a definition of “kiln 

operating day” to further address questions regarding the compliance demonstration period. In 

general, if the kiln operates during a 24-hour period, the CEMS must operate too.

Initial performance demonstration recommendations

Comment: One commenter (2855) stated that the initial performance demonstration should be 

based on a properly calibrated and compliant CEMS or Sorbent Trap System (if such systems 

become available and are demonstrated to perform acceptably), and the initial performance test 

result must be based on the calculated average lb mercury/million ton clinker produced for 

30 kiln operating days. A definition for kiln operating day must be established and must reflect a 

specified number of hours of kiln or raw material dryer operation at normal production 

conditions and a minimum number of hours of quality assured monitoring data. Days with fewer 

operating hours or insufficient monitoring data are not included in the 30 day average. 

Response: We agree that a definition of “kiln operating day” is needed, and have added it to the 

final rule. We have not specified a minimum number of hours of kiln or raw material dryer 

operation; a kiln operating day is any day the kiln is operating, and all valid data (for hours when 

the process is operating) for all operating days are included in the 30 day average.

Request daily instead of hourly mercury concentration data

Comment: One commenter (2855) stated §63.1349(b)(5)(i) requires collection of hourly

mercury concentration data which will not be available for sorbent trap monitoring systems and 

is not required by PS-12B. The commenter suggested that daily mercury emission rate averages 

would be adequate.

Response: The final rule has been clarified to address this situation. For example, if sorbent 

traps are collected every 7 days, each daily average would be assumed to equal the 7-day

average.
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Testing with raw mill on and raw mill off

Comment: One commenter (2855) stated that EPA should clarify that separate performance tests 

are not required for mill on and mill off conditions in the discussion in §63.1349(b)(5)(i) about 

demonstrating mercury compliance.

Response: We have clarified this language in the final rule to state that the raw mill off testing 

provision for mercury does not apply to a kiln equipped with and demonstrating compliance 

using a mercury CEMS.

Calculation of monthly mercury emissions

Comment: One commenter (2894) disagreed with the calculations to determine monthly

mercury mass emissions (Ref Eq. 5, page 21187, col 2). The commenter stated that this 

calculation could result in large biases. The commenter suggested an alternative calculation that 

multiplies the hourly average mercury concentrations by the hourly average flow rates and totals 

these values for the month to determine mercury mass emissions. 

Commenter 2894 stated that total monthly mercury mass emission must be divided by the clinker 

production rate during the same calendar month in order to determine compliance. Mercury

monitoring systems of any type are capable of determining only mercury concentrations. It 

appears that even the most conscientious plant operators will thus not know until well after the 

month has elapsed whether they were in compliance for that month.

Commenter 2894 stated that in cases where plant operators go through the effort to install 

systems capable of continuously measuring mercury concentrations and stack flow rates, it 

seems only fair and reasonable that the EPA devise a metric that allows plants to determine on an 

ongoing basis whether they are complying with the regulation.

Response: The commenter misinterpreted compliance equation 5 (74 FR at 21187) to require a 

determination of monthly mercury mass emissions and a monthly average flow rate. As 

recommended by the commenter, section 63.1349 (b)(5)(i) of the final rule requires the kiln 

owner or operator to measure and record hourly mercury concentration data and stack gas 

volumetric flow rates. These measurements are to be used to calculate daily mercury emission 

rates. Owners or operators are also required to operate a system to measure the hourly clinker 

production rates, either directly or indirectly through measuring kiln feed rates and applying a 

factor for converting feed rates to clinker production rates (section 63.1350(o)). They must 

record both the daily kiln feed rates and clinker production rates. Using the daily mercury

concentration data, daily stack gas flow rates and daily production rates, the owner or operator 

can track their performance on an ongoing daily basis rather than once a month.

2.5.4.1 Performance Specification 12A, 12B, and Procedure 5

PS-12A

Comment: One commenter (2638) stated that PS-12A should not be generalized to unspecified 

source categories other than portland cement. Because emission standards and measurement 

methods are not written independent of each other, defining the measurement method in effect 
83

defines the emission limit/standard for other, unspecified sources. By generalizing this 

measurement technology to vapor phase mercury, the EPA appears to want to generalize the 

emission standards for other, as yet to be specified sources to vapor phase mercury. By doing 

this, the EPA greatly inhibits the development of new methods that might measure total mercury.

Response: EPA will only apply PS-12A to other source categories through specific notice and 

comment rulemaking, and only when it is appropriate to do so. We are not opposed to the 

concept that PS-12A could also be applied to monitoring systems that also incorporate nongaseous mercury in the mercury measurement for this or any other appropriate source category

(see §63.7 (f)). However, EPA does not have any evidence that any appreciable non-gaseous 

mercury is present in the emissions from this particular source category.

Comment: One commenter (2638) stated that PS-12A and ongoing quality assurance should be 

re-written to replace contemporary technology-specific requirements with generalized 

measurement-objective driven requirements. The commenter provided comments about testing 

linearity, calibration drift, accuracy, system integrity, reagents and standards, and span value. 

Response: We disagree that PS-12A is technology-specific. We recognize that some 

performance procedures of PS-12A may be more difficult for some instruments and that some 

modifications to performance procedures may be necessary. EPA has a program in place to deal 

with this situation through the alternative test method request and approval/disapproval 

provisions of §63.7(f).

Comment: One commenter (2638) suggested specific changes to PS-12A and Procedure 5:

 Subsection 6.1.1 Data Recorder Scale: Should be replaced to simply require the operator 

to include the range defined by the zero and span values. The EPA proposed requirement 

seems to be based on old technology and defining this range with a specific numeric 

requirement (two times the standard) serves no functional purpose and unnecessarily

restricts development. 

 Subsection 6.1.2 CE determination: Change zero to low and upscale to high.

 Section 8.0 PS Tests: The EPA should re-write this section around clearly defined 

analytical objectives of establishing the CEMS initial accuracy, precision, linearity, 

stability and system integrity based on some of the same principals used in EPA Method 

301.

 Subsection 8.1.3 Extraction point: This should be re-written to allow for possible in situ 

monitoring systems that do not require sample extraction.

 Section 3.0 Definitions: A new subsection should be added defining zero or the bottom of 

the range for valid results, and instructions as to what value to use when a result falls 

below this defined concentration. The commenter recommended that zero be replaced 

with detection limit as defined by the EPA in Title 40, Appendix B Part 136 as the 

minimum concentration of a substance that can be measured and reported with 99% 

confidence that the analyte concentration is greater than zero. If the concentration is less 

than this concentration, the reported value should be replaced with a concentration equal 

to the detection limit.
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Response: Subsection 6.1.1 of PS-12A has been revised in response to comments received.

Subsection 6.1.2 PS-12A has been revised to be consistent with Section 7.1 of PS-12A on 

reference gases. The relative accuracy test audit or RATA of PS-12A is designed to assess the 

overall performance of the instrumental measurement system, including the representativeness of 

the sampling (i.e., probe location). PS-12A is not intended to address method detection limits.

Comment: One commenter (2837) provided analytical detail related to initial and on-going 

quality assurance:

 National Institute of Standards and Technology (NIST) certified traceable sources of 

elemental and oxidized mercury vapors are not generally needed to demonstrate CEMS 

compliance with performance based quality parameters such as linearity, accuracy, 

precision, stability or system integrity for either initial CEMS certification or on-going 

quality assurance and should be removed from both PS-12A and Procedure 5.

 The calibration check requirement currently in PS-12A and Procedure 5 allows the same 

mercury generator used to calibrate the CEMS to be used to check the calibration. Thus, 

they are not independent and a drift in the generator output would cause a drift in the 

CEMS calibration. Spiking mercury into clean, conditioned, interference-free air does not 

provide traceability to NIST standards for assurance of calibration accuracy.

 Spiking mercury into clean, conditioned, interference-free air does not provide quality

assurance of system integrity, analyte transportability, sensor response, etc.

 The current calibration drift check period is technology specific and should be defined by 

the system operator with performance-based protocols to demonstrate the applicability of 

the selected period.

Response: The NIST traceability and daily calibration requirements of PS-12A are consistent 

with the Agency’s other compliance monitoring requirements in 40 CFR Part 60 which require 

NIST traceable “protocol” gases for CEMS quality assurance/quality control. This approach has 

proven to be very effective for assessing overall system performance (e.g., sample transport and 

analyzer accuracy) through introduction of the reference gases at the CEMS probe. Dynamic 

spiking with elemental and oxidized mercury gases through the probe would be another way to 

accomplish this performance check and would certainly be encouraged as a potential alternative 

test method procedural request under §63.7(f). EPA believes that the requirements for NIST 

traceability of calibration gas generators are sufficient to address drift of the generators.

Comment: One commenter (2855) stated that PS-12A requires a system integrity check using an 

oxidized mercury NIST calibration source, which is designed to ensure the convertor portion of 

the mercury CEM is converting all of the mercury to elemental mercury. The commenter stated 

that there is a discrepancy between the oxidized and elemental mercury calibrators of about 7% 

in both Tekran and ThermoScientific instruments and that the cause of this discrepancy is still 

unknown.

Response: The commenter is correct regarding the discrepancy between the oxidized and 

elemental mercury calibrators of about 7 percent for the Tekran instrument; however, the Interim 

EPA Traceability Protocol for Qualification and Certification of Elemental Mercury Gas 

Generators and the Interim EPA Traceability Protocol for Qualification and Certification of 
85

Oxidized Mercury Gas Generators (July 01, 2009) recognizes this issue and provides a 

straightforward remedy. The protocol specifies that until the time that NIST traceability of 

evaporative oxidized mercury standards generators can be evaluated by direct measurement, the 

generator manufacturers may use a model-specific factor in their software to adjust the calibrated 

output of their HgCl2 generator to correspond with their NIST certified elemental generators, 

thus negating the discrepancy. The generator manufacturer must then provide the end user with 

the exact value of this correction factor and instructions for its application, and have derivation 

data available to the end user.

Comment: One commenter (2855) stated that EPA should not revert to 2004 CEMS 

performance specifications and should not require any specifications that are more restrictive 

than the 40 CFR 75, Appendix A and B requirements promulgated in January 2008.

Response: After consideration of the potential variability between the learning curves of CEMS 

operators that new users of Hg CEMS may experience, we have revised the relative accuracy

specification in PS-12A from 10 percent to 20 percent. We believe, however, that the implication 

of this change is minor and short-lived because most facilities that install mercury CEMS will 

find that they readily achieve relative accuracies far better than 20 percent.

Comment: One commenter (2855) stated that after field validation, and promulgation of 

instrumental CEMS and technical specifications and after NIST traceable calibration standards at 

the necessary concentrations are available, EPA should allow at least one year for purchase, 

installation and start-up of CEMS and a one-year trial implementation period before requiring 

the use of monitoring data to demonstrate compliance with emission limits.

One commenter (2144) recommended that EPA consider alternative QA procedures for mercury 

CEMS but without delaying final rule promulgation.

Response: The amendment to the Portland Cement NESHAP will not become effective until 60 

days following promulgation for new sources and existing sources will have up to 3 years to 

install controls and monitoring systems (see Section 63.1350(i)). The National Institute of 

Standards and Technology (NIST) has recently completed certification of a ‘NIST Prime’ 

elemental mercury gas generator at concentrations of 41, 68, 85, 105, 140, 185, 230, 287, and 

353 μg/m3 and mercury gas generator vendors may now submit elemental mercury gas 

generators for certification to serve as ‘Vendor Primes’. Therefore NIST traceable mercury gas 

standards can now be made available in concentrations that exceed the equivalent mass standards 

for both existing and new kilns by between one and two orders of magnitude, thus providing the 

capability to accurately report excursions well beyond either standard. The rule effective date 

should provide ample time for facilities to meet mercury monitoring system installation and 

certification requirements.

Comment: One commenter (2855) provided the following specific comments on PS-12A:

 Establishing the span value at twice the concentration corresponding to the emission 

limitation is acceptable for cement plants provided that reasonable provisions are 

included for certification and quality assurance of the mercury CEMS when emissions 

exceeding the span value are periodically encountered (such as for plants with in-line raw 
86

mills during mill off operation). The commenter provided suggested amendments to the 

Subpart LLL monitoring provisions.

 The definition of span value should be changed, explicit procedures for its calculation 

should be added, and the value should be rounded to established ranges. The definition 

could be modified by the addition of the phrase Span value means the upper limit of 

intended measurement range during normal ‘mill on’ operation which may be exceeded 

during ‘mill off’ operation or other short-term conditions lasting less than 24 consecutive 

kiln operating hours. Or the first sentence in the EPA proposed definition could be 

eliminated. Alternatively the span value could be specified in the applicable Subpart 

(Subpart LLL) where the specific requirements are more appropriately addressed.

Response: We have modified the definition of span in PS-12A to provide additional flexibility

and have adopted the commenter’s suggestion to include source category-specific provisions 

regarding the span in paragraph 63.1350(n) of Subpart LLL. We agree that the quality of 

measurements outside the calibration range should be assessed and could be further documented 

by extending the calibration range or other appropriate means. The commenter provided the 

following three approaches that EPA would consider appropriate:

 If emissions exceed the span value for more than 5 percent of the kiln operating time, the 

CEMS operator could conduct “direct calibrations” of the Hg analyzer bypassing the 

dilution module. Because the Thermo and Tekran Hg CEMS operate on a dilution ratio of 

30 or 50 to 1, the calibrated range of the Hg analyzer will be 30 or 40 times the upscale 

calibration value. Hence, for a system calibrated to measure 0-10 μg/m3through the 

entire measurement system, the analyzer would be calibrated accurate to between 0 and

300 μg/m3.

 The ability of the CEMS to quantitatively transport high concentration levels of oxidized 

Hg through the probe, filter, filter cake, sample lines, and the ability of the CEMS 

converter to reduce the oxidized Hg to elemental Hg should be confirmed initially and 

quarterly by injecting a high level HgC12 calibration gas standard at the sample probe, 

upstream of the PM filter. This high level system integrity test should be performed at a 

concentration approximating the maximum hourly emission concentration during the 

preceding three months or other representative high level concentration. The high level 

system integrity check is acceptable if: the stable Hg CEMS response is within ± (some 

percentage to be determined based on future field evaluations) of the reference value, and 

the system returns to normal operating level within 30 minutes of ceasing the calibration 

gas injection, or the time integrated Hg CEMS response is equivalent to the total mass of 

HgC12 injected within ± (some percentage to be determined based on future field 

evaluations).

 As an alternative to the high level system integrity checks, the CEMS operator could 

elect to demonstrate the accuracy of Hg CEMS measurements exceeding the span level 

by conducting a three-run relative accuracy audit (RAA), preferably when mercury levels 

are outside the calibrated range of the CEMS . The three-run RAA would be performed 

using Method 30B as the reference method following the procedures described in 

Procedure 5.
87

Comment: One commenter (2855) said that specific procedures should be provided in Subpart 

LLL for the calculation of the emission concentration equivalent to the 43 lb/million ton clinker 

(existing sources) or 14 lb/million ton clinker (new sources).

Response: Facilities can rearrange Equation 3 of Subpart LLL in order to calculate these 

quantities using their production rates and volumetric flow rates.

Comment: One commenter (2855) said that the calculated span value should be rounded to the 

nearest 10 μg/m3level as has been the practice for mercury CEMS because of technical 

limitations associated with the elemental Mercury gas generators and specific requirements to 

establish NIST traceability.

Response: We have modified the definition of span in Section 3.5 PS-12A to allow for 

additional flexibility in setting the span and have used commenter’s recommendations and added 

a provision in paragraph 63.1350(n) of Subpart LLL to allow for rounding of the span value to 

the nearest multiple of 10 μg/m3of total mercury.

Comment: One commenter (2855) said that the PS-12A requirements at 6.1.1 Data Recorded

Scale are misleading, ambiguous and obsolete and should be replaced by a relevant specification 

for data recording and an appropriate definition, (consistent with Span Value) for the high level 

value.

Response: Subsection 6.1.1 of PS-12A regarding the data recorder scale has been revised to 

respond to comments received. We have simplified the specification to clarify that the scale must 

at a minimum include zero through the span value, but the scale is not limited to that range.

Comment: One commenter (2855) said that the PS-12A requirements at 6.2 Reference Gas 

Delivery System are ambiguous, unlikely to be achieved exactly in practice, and without means 

of verification. The commenter recommends changing the section from The reference gas 

delivery system must be designed so that the flowrate of reference gases introduced to the CEMS 

is the same at all three challenge levels specified in Section 7.1, and, at all times exceeds the 

flow requirements of the CEMS. To The reference gas delivery system should be designed so that 

the referenced gas flow rate is approximately the same (i.e., ± 20%) at each challenge level.

Response: We have revised the language of section 6.2 of PS-12A to specify that the reference 

gas delivery system must be designed so that the flow rate exceeds the sampling system flow rate 

of the CEMS and that the gas is delivered to the CEMS is at atmospheric pressure.

Comment: One commenter (2855) said that PS-12A Section 7.1 requires the use of NIST 

certified or NIST Traceable standards for both elemental mercury and oxidized mercury, which 

are not currently available, and may not be available in the future at the specified levels, 

depending on EPA’s resolution of the span value.

Response: As noted above, NIST has recently completed certification of a ‘NIST Prime’ 

elemental mercury gas generator at concentrations of 41, 68, 85, 105, 140, 185, 230, 287, and 

353 μg/m3and mercury gas generator vendors may now submit elemental mercury gas 

generators for certification to serve as ‘Vendor Primes’. Therefore, as previously stated, NIST 

traceable mercury gas standards can now be made available in concentrations that exceed the 
88

equivalent mass standards for both existing and new kilns by between one and two orders of 

magnitude, thus providing the capability to accurately report excursions well beyond either 

standard.

Comment: One commenter (2855) said that PS-12A Section 8.1.1 includes a vague requirement 

to use a sampling location that has been shown to be free of stratification for mercury or 

alternatively, sulfur dioxide (SO2) and nitrogen oxides (NOx) through concentration 

measurement traverses for those gases. This requirement should be changed to a suggestion or 

guidance.

Response: We have revised language in Section 8.1.1 to specify that the sampling location must 

be representative of the stack gas concentration of mercury and, as the commenter suggested, 

have modified the requirement to use a location shown to be free of stratification to be a 

recommendation.

Comment: One commenter (2855) said that the PS-12A criteria for the linearity test procedures 

are more restrictive than the Part 75, Appendix A criteria, are inconsistent with the uncertainty of 

calibration materials defined by Interim EPA Traceability Protocols, and should be relaxed.

Response: By specifying the linearity test procedure measurement error criterion as a function of 

span, this criterion is generally less restrictive at the lower gas concentrations than were the prior 

Part 75, Appendix A criteria. We have, however, reconsidered the linearity test procedure 

specifications and, given the current quality of the available oxidized mercury gas standards, we 

have decided to increase the allowed measurement error for the oxidized mercury standards to 

+ 10 percent to be consistent with the target criteria in the EPA Interim Traceability Protocol for 

Qualification and Certification of Oxidized Mercury Gas Generators.

Comment: One commenter (2855) said that the PS-12A criteria for the calibration drift (CD) 

test procedure: (a) omit the absolute CD specification included in the Part 75, Appendix A 

criteria, (b) are inconsistent with the uncertainty of calibration materials defined by EPA draft 

interim traceability protocols, and (c) should be relaxed.

Response: With the exception of the alternative specification for a span value of 10 μg/m3 or 

less, the PS-12A criterion for calibration drift is essentially identical to the Part 75, Appendix A 

criteria for calibration error.

Comment: One commenter (2855) said that the proposed revisions to Subpart LLL and PS-12A 

fail to specify the conditions under which the relative accuracy test is performed which will lead 

to inconsistent interpretations and implementation requirements. Subpart LLL should specify

that the CEMS relative accuracy test be performed at the most prevalent operating condition (i.e., 

mill on for plants with in-line raw mills).

Response: We have revised paragraph 63.1350(n) of Subpart LLL to specify operating 

conditions for relative accuracy testing.

Comment: One commenter (2855) said that sections 9.0 (Quality Control) and 10.0 (Calibration 

and Standardization) are both reserved. Quality Control procedures and Calibration and 

Standardization procedures must be considered to determine the overall validity and 
89

reasonableness of the performance specification. Without these integral sections, an evaluation 

of the acceptability of this specification cannot be made. When completed, EPA should repropose PS-12A for public comment.

Response: These section headings are a result of using a standardized method format originally 

specified by EPA’s Environmental Monitoring Management Council [see 

http://www.epa.gov/ttn/emc/guidlnd/gd-045.pdf]. The substance of these reserved sections are 

covered elsewhere in PS-12A, Procedure 5, and the Interim Traceability Protocols for Elemental 

and Oxidized Mercury Gas Generators.

Comment: One commenter (2855) said thatPS-12A as proposed would make the relative 

accuracy specification stricter for certain CEMS than is required by Part 75, Appendix A and B.

Response: After consideration of the potential variability between the learning curves for CEMS 

operators that new users of Hg CEMS may experience, we have revised the relative accuracy

specification in PS-12A from 10 percent to 20 percent. We believe, however, that the implication 

of this change is minor and short-lived because most facilities that install Hg CEMS will find 

that they readily achieve relative accuracies far better than 20 percent.

Comment: One commenter (2915) provided the following specific comments on PS-12A:

Section 3.5–Span value is an obsolete term. Current technology has a linear measurement range 

that covers several orders of magnitude.

Instead of two times the emission standard the span value should be a fixed number in terms of 

measurement units (μg/m3). Like this proposed rule revision, many mercury emission limits are 

not expressed in terms of μg/m3. The proposed cement MACT is expressed in pounds of mercury 

per million tons of clinker. EPA should revise Section 3.5 to state that the span should be set in 

accordance with applicable regulations for the use of the Mercury CEMS.

The commenter suggested a revised definition of span: Span Value means the intended upper 

limit of the mercury concentration measurement range. The span value is specified in the 

applicable subpart.

Response: We have modified the definition of span in PS-12A to provide additional flexibility in 

setting a span value including allowing for rounding up to the nearest multiple of ten and 

clarifying that the applicable subpart may contain more specific provisions regarding the span 

value for specific source category. In this case, we have taken another commenter’s suggestion to 

define span value for this source category in paragraph 63.1350(n) of the subpart based on the 

intended upper limit of the mercury concentration during “mill on” operation and approximately

equivalent to two times the emission standard.

Comment: One commenter (2915) stated that there are a limited number of NIST traceable 

calibration levels available. Since the available calibration values are all tied to specific span and 

linearity test values, defining the span in terms of the emission standard will likely result in spans 

that are inconsistent with the NIST traceable concentrations.
90

Response: As noted above, NIST has recently completed certification of a ‘NIST Prime’ 

elemental mercury gas generator at concentrations of 41, 68, 85, 105, 140, 185, 230, 287, and 

353 μg/m3and mercury gas generator vendors may now submit elemental mercury gas 

generators for certification to serve as ‘Vendor Primes’. Therefore, as previously stated, this 

capability means that NIST traceable mercury gas standards can now be made available in 

concentrations that exceed the equivalent mass standards for both existing and new kilns by

between one and two orders of magnitude, thus providing the capability to accurately report 

values both below and well above either standard. Also, as described in previous responses, we 

have revised the definition of span to provide additional flexibility in setting the span value 

consistent with the available NIST traceable concentrations. 

Comment: One commenter (2915) suggested that EPA review the Interim Traceability Protocols 

for elemental and oxidized mercury generators so that there will be regulatory compatibility.

Response: At the current time, we do not anticipate any issues with the regulatory compatibility 

of the Interim Traceability Protocols used to certify the NIST traceability of gases produced by

mercury gas generators; however, we do plan to review and update the protocols in the future

including clarifying that the protocols are not limited to only providing procedures to qualify and 

quantify the performance of mercury gas standards generators below 40 μg/m3.

Comment: One commenter (2915) said that in Section 3.7, EPA proposes to define calibration 

drift in terms of a test performed on the CEMS after a period of operation during which no 

unscheduled maintenance, repair, or adjustment took place. The clause during which no 

unscheduled maintenance, repair or adjustment took place should be removed. In the 

commenter’s experience, unlike SO2 and NOx CEMS, mercury CEMS are likely to require a 

significant amount of maintenance, repair and adjustment. That same clause in PS-2 has been 

subject to considerable debate and interpretation over the years and the commenter believes that 

including it here will only result in further confusion. EPA also has not explained why such a 

limitation is needed in this definition. 

Response: We have removed the term ‘adjustment’ from this phrase in Section 3.7 of PS-12A as 

we clearly consider adjustment following the daily drift check to be an appropriate option (see 

also Sections 4.2 and 4.3 of Appendix F, Procedure 2 and of proposed Procedure 5).

Maintenance or repair of the Hg CEMS during a 7-day calibration drift test is not acceptable as 

the point of the test is to confirm that the system can operate for 7 days without unacceptable 

drift.

Comment: One commenter (2915) said that in Section 6.1.1–EPA proposes several 

requirements related to [t]he Mercury CEMS data recorder output range. These requirements 

are obsolete. All recording is now done by computer and virtually all data transmission and 

recording is digital. Digital data transmission and management allows one to eliminate the span 

and range language problem because digital data have no range. Such a change will allow 

sources to utilize the full several order of magnitude measurement capabilities of modern 

analyzers–especially mercury analyzers.

Response: Section 6.1.1 of PS-12A regarding the data recorder scale has been revised to respond 

to the comments received. We have simplified the specification to clarify that the scale must at a 
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minimum include zero through the span value. This revision will allow sources to utilize multiple 

orders of magnitude, as needed.

Comment: One commenter (2915) disagreed with EPA’s proposed requirement that the 

measured value not exceed 95 percent of the high value. The measured value should be allowed 

to be as high as the calibration value. This section should be eliminated or modified to 

accommodate modern analyzers.

Response: We agree with the commenter and this specification has been removed from Section 

6.1.1 of PS-12A.

Comment: One commenter (2915) said that in Section 6.2–EPA proposes to require that the 

reference gas delivery system be designed so that the flow rate of the reference gas is the same at 

all levels. The commenter is not aware of any reason for this requirement and EPA offers none. 

Several of the commercial mercury calibrators (including the market leader) are designed to vary

the flow rate of the reference gas, and the gas sampling probes are designed to vent any excess 

flow. This proposed requirement would render those calibrators ineligible for use under the 

proposed rule, without any stated justification. In the commenter’s view, the only pertinent 

requirement in this section is that the flow of the reference gas exceeds that required by the 

CEMS sample probe design.

Response: We have revised the language of Section 6.2 to specify only that the reference gas 

delivery system must be designed so that the flow rate exceeds the sampling system flow rate of 

the CEMS and that the gas delivered to the CEMS is at atmospheric pressure.

Comment: One commenter (2915) said that in Section 7.1.1–EPA proposes to require that the 

zero level reference gas concentration be 0-20 percent of the span value. The zero-level should 

be made 0-30 percent of span instead of 0-20 percent of span to capture the best available NIST 

traceable concentrations. For example, the available NIST concentrations for a 0-10 μg/m3span 

are 1.1, 1.3 and 2.7 μg/m3. Of these, the 2.7 μg/m3concentration has been the standard low-level 

calibration/linearity concentration because its uncertainty, per NIST traceability calculations, is 

much lower than the other two concentrations.

Response: The interim protocols for certifying mercury gas generators allow sufficient 

flexibility to certify the gas generators in an appropriate range from existing NIST traceable gas 

standards. For the case described by the commenter, potential options are to (1) use a zero gas 

for the zero level reference gas, (2) use the 2.7 μg/m3 gas as the zero level reference gas, but use 

a zero gas in addition, or (3) request that the gas generator vendor provide a generator that can 

deliver a standard at 2.0 μg/m3 or below using guidance in the protocols.

Comment: One commenter (2915) said that in Section 8.1.1, because mercury CEMS generally 

use a single point measurement, EPA proposes to require use of a location that has been shown 

to be free of stratification for Mercury or alternatively, SO2 and NOx. The provision then states 

that if the RA test is failed because of the location, EPA may require that the CEMS be relocated. 

The commenter stated that this provision is not reasonable and explains why. 
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Response: We have revised the language in Section 8.1.1 to specify that the sampling location 

must be representative of the stack gas concentration and have modified the requirement to use a 

location shown to be free of stratification to be a recommendation rather than a requirement. 

Comment: One commenter (2915) said that in Section 8.3–EPA proposes to require that CEMS 

meet a linearity specification of 5 percent of the span value. According to the commenter, this 

provision has several problems. Given the field experience with mercury CEMS, a linearity

specification of 5 percent of span would likely be failed very frequently and the commenter 

suggested that EPA analyze these data to provide justification for this linearity specification. 

Alternatively, EPA could change the specification to ±10 percent of span. In addition, EPA 

already determined that a 5 percent of span specification without an alternative specification for 

low emitters is unreasonably stringent (74 FR 4328). As a result, EPA should include an 

alternative specification of ±0.8 μg/m3absolute difference.

Response: We have reconsidered the linearity test procedure specifications and, given the 

current quality of the available oxidized mercury gas standards, we have decided to increase the 

allowed measurement error for the oxidized mercury standards to + 10 percent to be consistent 

with the target criteria in the EPA Interim Traceability Protocol for Qualification and 

Certification of Oxidized Mercury Gas Generators.

Comment: One commenter (2915) said that in Section 8.4.3, EPA proposes to require that 

CEMS meet a calibration drift specification of 5 percent of the span value. The problem in this 

section is the same as discussed in the Section 8.3 above. The specification cannot be supported 

by field data and should be changed to ±10 percent of span with a ±1.0 μg/m3absolute 

difference, whichever is less restrictive. This specification will be similar to the Clean Air 

Markets Rule (CAMR) rule specification in Part 75, which was difficult to achieve.

Response: We believe that the calibration drift specification of 5 percent of the span value is 

reasonable and that many installations of mercury CEMS have been able to achieve the 

specification.

Comment: One commenter (2915) said that in Section 8.5.4, EPA proposes to require a 

minimum sample time of 30 minutes for Method 30A. The sample time specification is 

inconsistent with the method. The sampling time for Method 30A will vary depending on the 

number of traverse points. The minimum sampling time for Method 30B is 30 minutes and that 

is not included in Section 8.5.4.

Response: The commenter is correct. Method 30A sampling time depends on the number of 

traverse points. The reference should have been to Method 30B and we have revised the section 

accordingly.

Comment: One commenter (2915) said that in Section 8.5.5, EPA proposes to require use of 

paired reference method values when using certain methods to perform a relative accuracy test 

audits (RATA), including Method 30A. Method 30A should be removed from the method list in 

this section because it does not provide paired reference method values.

Response: The commenter is correct; Section 8.5.5 of PS-12A has been revised to remove the 

reference to Method 30A.
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Comment: One commenter (2915) said that in Section 8.5.6.2, EPA proposes to include relative 

difference performance criteria applicable to paired reference method values used in RATAs. 

Method 30B provides for an acceptance criteria ±0.2 μg/m3absolute difference between data 

pairs in addition to the 20 percent relative difference criteria. The absolute difference criteria are 

missing from this section. The commenter does not believe it is appropriate to modify a reference 

method in a Performance Specification. EPA should add the alternative specification or state that 

alternative specifications in individual reference methods may also be used.

Response: We have revised Section 8.5.6.2 of PS-12A to be consistent with Method 30B.

Comment: One commenter (2915) said that in Section 13 the relative accuracy, linearity and 

calibration drift specifications are too stringent and will result in a significant number of failures. 

The commenter suggested that the linearity, calibration drift and relative accuracy specifications 

in this section mirror those that were promulgated in Part 75 for use under CAMR. A large 

quantity of field data show that present day mercury CEMS technology cannot routinely achieve 

the specifications proposed in Section 13.

Response: These issues have been addressed in earlier responses.

Comment: One commenter (2894) stated that problems may occur when using mercury

calibration gases. The proposed rule requires that all mercury calibration gases be NIST 

traceable. Currently, the maximum concentration capable of being generated by the NIST Prime 

elemental mercury generator is approximately 38 μg/m3. The EPA Interim NIST Traceability

protocol for elemental mercury requires that any candidate calibrator’s test concentration be 

within 25 percent of the closest NIST certified concentration. Thus, the highest concentration 

that it is possible to certify as NIST traceable is currently 47.5 μg/m3. This is far too low to be of 

use for cement kilns where the most common span value will be 260 μg/m3. The commenter 

stated that this problem can be solved in one of several ways:

 If the bracketing system used for certification is demonstrated to be linear, there would be 

no obstacle to having a candidate calibrator certified at concentrations several times the 

concentration of the reference calibrator. This applies to both the NIST and vendors’ 

bracketing systems. A change to the 25% difference limit would be required.

 NIST could certify a NIST prime calibrator at the target concentrations for the cement 

rule. Note that using the same NIST prime unit for both high and low concentrations 

might impact the certification accuracy of the prime unit for low concentrations due to 

residual contamination. Thus a second NIST prime calibrator for high concentrations 

would likely be required.

Response: As noted earlier, NIST has recently completed certification of a ‘NIST Prime’ 

elemental mercury gas generator at concentrations of 41, 68, 85, 105, 140, 185, 230, 287, and 

353 μg/m3and mercury gas generator vendors may now submit elemental mercury gas 

generators for certification to serve as ‘Vendor Primes’. Therefore NIST traceable mercury gas 

standards can now be made available in concentrations that exceed the equivalent mass standards 

for both existing and new kilns by between one and two orders of magnitude, thus providing the 

capability to accurately report excursions well beyond either standard.
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Comment: One commenter (2894) stated that many of the span value concepts in this proposed 

rule date back to the days of strip chart recorders, analog instrumentation, and low resolution 

A/D converters. In these legacy systems, exceeding an upper output limit meant that all 

information was lost as the pen pegged or the A/D overloaded. In contrast, all modern CEM 

systems provide digital interfaces that transmit actual numbers. These are capable of high 

resolution over an unlimited dynamic range. Commenter 2894 suggested that vendors should be 

required to provide test data on the dynamic range of their CEM systems, particularly at high 

concentrations. The regulation should allow temporary exceedences of the span range provided 

that they fall within this linear range. (Currently, data is considered invalid if concentrations 

exceed the span range.) This is particularly essential if the rule requires the monitoring of 

mercury during SSM periods. This wide dynamic range should be allowed only on installations 

that do not artificially limit their dynamic range by using older 4-20 mA or other analog signal 

transfer methods.

Response: As explained in response to earlier comments, the data recorder scale of Section 6.1.1 

of PS-12A has been revised to respond to the comments received. We have simplified the 

specification to clarify that the scale must at a minimum include zero through the span value.

This revision will allow sources to utilize multiple orders of magnitude, as needed. In addition, 

we have modified the definition of span in Section 3.5 to provide additional flexibility in setting 

a span value including allowing for rounding up to the nearest multiple of ten and clarifying that 

the applicable subpart may contain more specific provisions regarding the span value for specific 

source category. For these amendments to Subpart LLL, we have taken another commenter’s 

suggestion to define span value for this source category in paragraph 63.1350(n) of the subpart 

based on the intended upper limit of the mercury concentration during “mill on” operation, but at 

least approximately equivalent to two times the emission standard.

Comment: One commenter (2894) suggested that the new regulation should ensure that as few 

new span ranges as possible are defined. According to the commenter, in the U.S. power plant 

environment, mercury levels are substantially lower than the emissions levels at cement kilns. 

The span ranges that have been defined for power plants are: 2 μg/m3(future use), 5 (future use), 

10, 20, 30 and 40 μg/m3. This is more than are actually required, given the performance of all 

current CEM systems. (In particular, the span range of 30 μg/m3is superfluous.)

Each of these defined span ranges requires three distinct and separate concentrations of 

calibration gas: low (20-30% of span), medium (50-60%), and high (80-100% of span). This 

requirement would pose an undue burden on both NIST and the vendors if too many new span 

ranges are defined.

The commenter stated that any requirements for dual span ranges for a CEM installation are 

archaic and should be deleted.

Response: With the revisions to the definition of span in PS-12A and Subpart LLL monitoring 

requirements described in the previous response, we have provided ample flexibility in span 

selection and have eliminated the need for dual spans.

Comment: One commenter (2894) suggested upgrades to PS-12A:
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 6.1.1 Data Recorder Scale. This section deals with obsolete strip chart recorder 

technology and should be either deleted or redrafted.

 6.2 There are actually four gas levels being used in CAMR power plant installations, not 

three: Zero, Low linearity, Mid Linearity and High span. There is an inconsistency here. 

(i.e., Should the Low Linearity gas actually be allowed to be in the range of 0-20% as 

specified in PS-12A or 20-30% as is current practice?).

 8.1.3 Mercury CEMS Sample Extraction Point. Are most cement kiln stacks sufficiently

large to allow sampling 1.0 meter from the stack wall?

 8.3 Linearity Procedure. Currently, power plant CEMS are required to inject at three nonzero concentrations, not two concentrations plus zero. Will replacement power plant 

regulations still require three non-zero concentrations or will this requirement be relaxed 

as per this section?

Response: Section 6.1.1 of PS-12A regarding the data recorder scale has been revised to respond 

to the comments received. We have simplified the specification to clarify that the scale must at a 

minimum include zero through the span value. This revision will allow sources to utilize multiple 

orders of magnitude, as needed.

We note that the vacated Clean Air Mercury Rule specifications are no longer relevant. The low 

(“zero-level”) reference gas must be in the range of 0 to 20 percent of span.

Based on the information we have, yes, most cement kiln stacks are sufficiently large to allow 

sampling 1.0 meter from the stack wall.

Replacement regulations for mercury emissions have not yet been proposed, so we cannot 

provide a definitive response to the question on Section 8.3. However, PS-12A allows linearity 

tests to be conducted at three non-zero concentrations or at two non-zero concentrations plus 

zero.

Comment: One commenter (2915) disagreed with the proposed mercury performance 

specifications and with the provisions for setting Mercury CEMS span values and the stringency

of the proposed performance specifications for both Mercury CEMS and sorbent trap monitoring 

systems (STMS).

Commenter 2915 stated that EPA’s proposed Mercury performance specifications include setting 

Mercury CEMS span values equal to twice the applicable emission limit and to use that span 

value to determine the levels at which the Mercury CEMS must be calibrated. 74 FR at 21172. 

EPA’s approach to span does not reflect the measurement capabilities of Mercury CEMS or the 

limited number of potential National Institute of Standards and Technology (NIST) traceable 

calibration gases available to calibrate Mercury CEMS of various spans.

Commenter 2915 stated that EPA also should define span in a manner that is consistent with the 

regulations and permits that are likely to require use of PS-12A and Procedure 5. Because most 

Mercury limits, including the ones EPA proposes in this rule, are expressed in terms other than 

μg/m3(e.g., lb per million tons of clinker produced, pound per trillion British thermal unit 

[lb/TBtu], or pound per megawatt hour [lb/MWh]), the commenter disagrees with defining the 

required Mercury CEMS span (which is expressed in μg/m3) in terms of the Mercury limit. 
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Instead, PS-12A should defer to the applicable regulation or permit to define the span (in mg/m3) 

that is most appropriate for the intended use.

Response: We have revised the definition of span in Section 3.5 of PS-12A as well as Subpart 

LLL to provide additional flexibility. The definition of span in PS-12A now clarifies that the 

span is the measurement range specified in the applicable regulation or other requirement. If the 

span is not specified in the applicable regulation or other requirement, then it must be 

approximately two times the emissions limit. The definition also allows for rounding up to the 

nearest multiple of ten. In Subpart LLL, paragraph 63.1350(n), we have defined the span value 

for this source category as based on the intended upper limit of the mercury concentration during 

“mill on” operation, but at least approximately equivalent to two times the emission standard and 

again allowed for rounding up to the nearest multiple of 10.

Comment: According to commenter 2915 EPA should provide more data to support its 

proposed tightening of the relative accuracy standard for both Mercury CEMS and STMS 

relative to the vacated CAMR standards. As a result of its work on the Interim Traceability

Protocols and other research efforts, EPA has had access to a considerable amount of additional 

field data. The commenter stated that the proposed linearity, calibration drift, and relative 

accuracy standards for Mercury CEMS are too stringent and may be frequently failed.

Response: As noted in prior responses, after consideration of the potential variability among the 

learning curves that new users of Hg CEMS may experience, we have revised the relative 

accuracy specification in PS-12A from 10 percent to 20 percent. We believe, however, that the 

implication of this change is minor and short-lived because most facilities that install Hg CEMS 

will find that they readily achieve relative accuracies far better than 20 percent.

We have also reconsidered the linearity test procedure specifications and, given the current 

quality of the available oxidized mercury gas standards, have decided to increase the allowed 

measurement error for the oxidized mercury standards to + 10 percent. We have not changed the 

calibration drift specification of 5 percent of the span value as we believe is reasonable as many 

installations of mercury CEMS have been able to achieve this specification.

PS-12B

Comment: Several commenters (2855 and 2915) provided specific comments about PS-12B. 

Commenter 2855 provided the following comments:

 EPA has mixed a PS with on-going quality assurance procedures making this procedure 

unnecessarily complicated. EPA should develop an Appendix F type procedure for ongoing quality assurance (QA) and eliminate the three section spike trap requirement for 

daily use.

 Section 6.1.1’s substitution of three-section traps in place of two-section traps is 

unnecessary. The addition of the third section is used for QA purposes. This requirement 

should be moved to the Appendix F procedure that EPA needs to develop for sorbent trap 

systems.
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 The third section spike trap should only be required when the duplicate trains do not meet 

the RD specification, during the initial relative accuracy test and for on-going QA such as 

quarterly audits.

Response: We recognize that the commenter is recommending that all quality assurance (QA) 

procedures related to sorbent trap-based mercury monitoring systems in PS-12B be moved to a 

separate procedure in 40 CFR 60, Appendix F; we agree that this approach is more consistent 

with our prior performance specifications and we have revised PS-12B to remove the on-going 

quality assurance procedures and have incorporated them into Procedure 5. The three-section 

trap required by PS-12B provides a routine quantitative indication of measurement performance 

analogous to the daily span check performed on gaseous mercury CEMS.

Comment: Commenter 2855 said that when spikes are required, the procedure should allow the 

use of liquid standard spikes that are traceable to NIST.

Response: We do not allow the use of liquid standard spikes in PS-12B as they are not 

representative of gaseous emissions of mercury.

Comment: Commenter 2855 said that this reference sentence in Section 1.2.2 should be deleted: 

Section 1.2.2. This specification is not designed to evaluate an installed sorbent trap monitoring 

system’s performance over an extended period of time nor does it identify specific techniques 

and auxiliary procedures to assess the system’s performance. The statement is incorrect. The fact 

that paired sampling trains meeting a relative deviation (RD) specification are required is a 

means for determining ongoing evaluation over extended period of time.

Response: We agree with the commenter and have removed Section 1.2.2 from PS-12B.

Comment: Commenter 2855 said that Section 8.1.1 should be changed to read select a location 

that is representative of Mercury emissions.

Response: We agree with the commenter and have revised Section 8.1.1 of PS-12B so that it is 

consistent with the corresponding section of PS-12A.

Comment: Commenter 2855 said that Section 8.3 should be deleted because the RATA 

procedure is redundant and unnecessary.

Response: It is agency policy to conduct relative accuracy testing of mercury monitoring 

systems. These RATAs are used to confirm the continuing accuracy and representativeness of 

compliance monitoring system measurements.

Comment: Commenter 2915 said that their comments on Section 8.1.1 of PS-12A apply to 

proposed PS-12B.

Response: Section 8.1.1 of PS-12B specifies only that the sampling location must be 

representative of the stack gas concentration of mercury with a suggestion to consider a location 

shown to be free of stratification for mercury, SO2, or NOx.
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Comment: Commenter 2915 said that in Section 8.2.3, for sources calculating Mercury mass 

emissions, EPA proposes to require determination of stack gas moisture content using a certified 

continuous moisture monitoring system. This requirement is too restrictive. The commenter 

suggested that EPA review the alternative moisture measurement options provided in Part 75 at 

75.11(b), 75.12(b) and Appendix K, 7.2.4. Similar language should be incorporated into PS-12B, 

especially the default moisture content and psychrometric chart look-up table language. In 

addition to the alternative of using the moisture monitor and various options defined in Part 75, 

the commenter stated that one or more of the carbon trap monitor vendors has a technique for 

recovering the moisture collected by the sampling train. That option should also be allowed. The 

term certified continuous moisture monitoring system is undefined; the commenter is not aware 

of a PS for certification of moisture monitors.

Response: We have revised Section 8.2.3 of PS-12B to remove the requirement for continuous 

moisture monitoring system certification and to allow for other moisture measurement options 

acceptable to the Administrator such as those noted by the commenter.

Comment: Commenter 2915 said that in Section 8.3.2 – EPA proposes an alternative relative 

accuracy specification of 0.5 μg/m3if the reference method value is less than 2.0 μg/m3. This 

alternative relative accuracy specification is inconsistent with the alternative specification in 

proposed PS-12A, Section 13.3 and there is no reason for the inconsistency. In addition, there are 

considerable field data to show that both PS-12A and PS-12B relative accuracy specifications are 

unrealistic based on present day technology and will result in a significant number of test 

failures.

Response: We have revised Section 8.3.2 of PS-12B to make it consistent with the 

corresponding section of PS-12A and, as noted previously, we have revised the relative accuracy

specification in PS-12B to 20%.

Comment: Commenter 2915 said that in Section 11.2, this section of PS-12B requires the 

analysis of the first glass wool plug in the trap, while PS-12A states that Method 30B does not 

require the analysis of the first glass wool plug (see Section 8.5.2 of PS-12A). If the first glass 

wool plug is included in the analysis, particulate Mercury will be measured not just vapor-phase 

Mercury. The commenter agrees with the PS-12A requirement because the intent is to not 

measure Mercury that may be on the particulate matter. It is clearly stated in Section 1.0 that the 

intent is to measure vapor-phase Mercury emissions.

Response: The first glass wool plug of the Method 30B sorbent tubes must be analyzed. We 

have clarified Section 8.5.2 of PS-12A to clarify that the sentence stating that the “filterable 

portion of the sample need not be included when making comparisons to the CEMS results” is 

only applicable to Method 29 and Method D6784-02.

Appendix F, Procedure 5

Comment: One commenter (2855) agreed with Section 4.1 requiring that corrective action or 

adjustment shall be performed when the CD exceeds twice the PS-12A limit, and Section 4.3 

specifying out of control criteria as CD checks results exceeding (a) twice the PS-12A limit for 

five consecutive daily periods, or (b) CD check result exceeding four times the PS-12A CD limit.
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Response: EPA notes the commenter’s support.

Comment: One commenter (2855) said the use of oxidized calibration standards for gas audits 

are redundant with System Integrity Checks required as part of the quality control requirements 

in Section 3.0 and should be deleted.

Response: We have provided some flexibility under Section 3.0 of Procedure 5 in establishing 

the acceptance criteria for the weekly system integrity check; we, therefore, on a quarterly basis 

require a more extensive two level accuracy audit using oxidized Hg gases that must meet 

specified criteria.

Comment: One commenter (2855) said that the language in Section 5.1.2 (2): “At a minimum, 

the audit gas should be introduced at the connection between the probe and sample line” is not 

appropriate and should be removed. 

Response: We agree with the commenter and have removed this sentence from Section 5.1.2(2) 

of Procedure 5.

Comment: Commenter 2855 said that quarterly gas audits will be performed using the elemental 

Mercury and oxidized Mercury calibration gas generators of the CEM system. Section 5.1.2 (3) 

requires use of NIST certified or NIST Traceable calibration materials for gas audits. However, 

NIST traceable gas standards will not be available may not be available at the required levels for 

several years.

Response: As noted previously, NIST has recently completed certification of a ‘NIST Prime’ 

elemental mercury gas generator at concentrations of 41, 68, 85, 105, 140, 185, 230, 287, and 

353 μg/m3and mercury gas generator vendors may now submit elemental mercury gas 

generators for certification to serve as ‘Vendor Primes’. Therefore NIST traceable mercury gas 

standards can now be made available in concentrations that exceed the equivalent mass standards 

for both existing and new kilns by between one and two orders of magnitude, thus providing the 

capability to accurately report excursions well beyond either standard.

Comment: Commenter 2855 said that the specification at Section 5.2.3 (2): For GA, ± 15 

percent of the of the average audit value or ± 5 ppm, whichever is least restrictive, is believed to 

be intended as ± 5.0 μg/m3.

Response: This was an inadvertent error; the specification in Section 5.2.3 (2) was intended to 

be ± 0.5 μg/m3 and the section has been revised to reflect this.

Comment: Commenter 2915 said that in Section 1.1, in the second paragraph EPA states that, 

Procedure 5 covers the instrumental measurement of Mercury as defined in PS-12. It is not 

perfectly clear on first reading that Procedure 5 is not applicable to Mercury measurement 

systems using PS-12B. PS-12B is performance-based and is self-validating. A sentence should 

be added making that fact clear.

Response: As noted in response to a previous comment, we have decided to revise PS-12B to 

remove the on-going quality assurance procedures and instead incorporate them into Procedure 
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5; thus, Procedure 5 will now be applicable to both PS-12A Hg CEMS and PS-12B monitoring 

systems when called for by the applicable regulation.

Comment: Commenter 2915 said that in Section 5.1.2(3), as proposed, the section states, Use 

elemental Mercury and oxidized Mercury...... This should be changed to read, Use elemental 

Mercury or oxidized Mercury......... It is not necessary to use both elemental and oxidized 

Mercury for this test because both are NIST traceable. 

Response: We disagree with the commenter’s recommendation; we believe it is important to 

obtain information on system linearity and a quantitative accuracy assessment for both species 

on a regular basis.

Comment: Commenter 2915 said that in Sections 5.1.3 and 5.2, EPA proposes to require the 

analysis of performance audit samples, except during audits following corrective action. 

However, EPA provides no information regarding the availability of such samples or explanation 

regarding how the results will be used. The commenter does not believe such samples exist for 

Mercury and notes that audit samples are not necessary for Methods 30A and 30B because they

are performance-based methods and are, therefore, self-auditing. This language also is 

inconsistent with the statement in Section 1.2 that Procedure 5 also requires the analysis of audit 

samples concurrent with certain reference method (RM) analyses as specified in the applicable 

RMs. EPA should revise this provision to include similar language that makes clear, for example, 

that audit sample analysis is not required for Methods 30A and B, because those methods do not 

require them. For other methods, EPA should explain the requirement and make clear that it does 

not apply if audit samples are not available. 

Response: We agree that this language on use of performance audit samples is not necessary in 

this procedure and have removed those references.

Comment: Commenter 2915 said that in Section 5.2.3, this section sets out the criteria for 

excessive audit inaccuracy. Based on the commenter’s experience, all of the specifications are 

too stringent. For RATAs, EPA refers to PS-12A. For Gas Audits, EPA proposes an alternate 

specification of ±5 ppm. Because Mercury CEMS do not read in ppm (they read in μg/m3), this 

specification makes no sense. This alternate specification should be changed to ±1.0 μg/m3. For 

RAAs, EPA proposes the greater of ±15 percent of the three run average, or ±7.5 percent of the 

applicable standard. These specifications are too stringent and EPA has provided no data to 

support them. EPA should revise the standard to ±20 percent of the three run average or 10 

percent of the applicable standard.

Response: We have made the following revisions to Procedure 5: (1) we have revised the RATA 

specification in Procedure 5 to make it consistent with the revised specification in PS-12A, (2) 

we have revised the specification in Section 5.2.3(2) to its intended value of ± 0.5 μg/m3, and (3) 

we have revised the specification in Section 5.2.3(3) for the relative accuracy audits to be ±20 

percent of the three run average or the equivalent of 10 percent of the applicable standard, 

whichever is greater, as suggested by the commenter.

Comment: One commenter (2915) said that in Section 5.3, EPA proposes to require a source to 

revise its QC procedures or modify or replace the Mercury CEMS if excessive audit inaccuracy
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occurs for two consecutive quarters. EPA provides no basis for this requirement or data to 

support its criteria for excessive audit inaccuracy. The consequences of failing performance 

specifications should be identified in the applicable regulation. In addition, the requirement to, 

modify or replace the Mercury CEMS is much too onerous. There are only two vendors that have 

Mercury CEMS that are compatible with these proposed regulations and the technology is what 

it is. The performance of both vendors is similar and requiring a change from one vendor to the 

other makes no sense.

Response: We disagree; if the mercury CEMS was capable of passing the initial RATA, then 

with modification, repair, or a change in the QC procedures, the system should be able to 

continue meeting the QA criteria.

Comment: One commenter (2837) stated that PS-12A and Procedure 5 appear to be written 

around the perceived capabilities and limitations of a specific CEMS technology. It is important 

to correct this because as written, these two documents have the potential to fix future 

technology and emission standards to the capabilities of the measurement technology around 

which they were written. This is most apparent in those sections where the specifications 

unnecessarily require certified NIST traceable gas standards or generators. The commenter 

provided further detailed discussion of this issue. The commenter requested that EPA modify

both PS-12A and Procedure 5 to remove requirements that are technology specific and replace 

them with performance based requirements.

Response: The use of NIST traceable mercury gases for system calibrations, checks, and 

linearity determinations is not specific nor exclusive to any particular type of CEMS technology.

We disagree that that their use is unnecessary; in fact, we believe that use mercury gases (in 

particular NIST traceable gases) is the only way to routinely confirm that the mercury in the 

stack gas matrix is being quantitatively transported from the stack to the instrumental analyzer.

2.5.5 Impacts

Costs

Comment: One commenter (2855) states that the industry believes installation and certification 

of HCl CEMS as currently proposed is expected to cost between $225,000-$250,000 plus 

another $30,000 for initial certification. The total costs for ongoing QA are unknown as facilities 

cannot install and certify HCl CEMS using Performance Specification-15. Additional costs for 

add on controls (e.g., wet scrubbers) to meet the extremely low concentration levels proposed are 

expected to cost upwards of $20,000,000.

Response: EPA estimated the cost of complying with the final HCl emission standards as the 

cost of installing and operating add-on control equipment and the cost of installing and operating 

continuous emission monitoring equipment. Total capital and annual costs for HCl CEMS were 

estimated to be $144,000 first time (or capital) cost, and $43,000 per year annual cost. Total 

capital cost of a wet scrubber for a new 1.2 million tpy kiln, including the cost of CEMS, was 

estimated to be $25.1 million per kiln. Cost of control for HCl is discussed further in, “Summary 

of Environmental and Cost Impacts for Final Portland Cement NESHAP and NSPS.”
102

Plant closures

Comment: Many comments were received regarding the effects of the proposed rules on plant 

closures.

Commenters 2298, 2483, 2506, 2507, 2651, 2653, 2654, 2661, 2667, 2671, 2672, 2811, 2812, 

2813, 2824, 2832, 2833, 2863, 2886, and 3218 stated that without the use of a subcategory

within the MACT rule allowing EPA to address the naturally occurring mercury in limestone of 

western cement plants, then plants like the Durkee Cement Plant in rural Oregon may have to 

close. The commenters explained that the loss of the Durkee Plant jobs would have a substantial 

impact on the local economy. 

Commenter 2832 stated that the CAA does not give EPA the authority to regulate, diminish, or 

steal away the financial and quality of life advantages that a community may have because of 

local desirable natural mined materials. Inclusion of emissions associated with such mined 

materials would effectively be a ban on their use and would exact a great toll on local 

communities. 

Commenter 2830 has determined that three of their existing plants could be forced to close with 

many of their wet kilns at high risk of closure, and high capital cost may also close long dry kilns 

should the 2009 proposed rule be implemented. 

Commenters 2830, 2840, 2841, 2863, 2886, 2916, and 3218 stated that should cement facilities 

close because of the proposed rule, the lost domestic supply of cement will be offset by imports, 

creating global increases in mercury and greenhouse gas emissions if these foreign plants are not 

regulated to the same degree, and increased transportation emissions. Commenter 2841 added 

that there would be an increase of NOx, volatile organic compound (VOC), PM, carbon 

monoxide (CO) and CO2 emissions from the transportation of raw materials.

One commenter (2786) disagreed with comments suggesting cement production will shift 

overseas due to weaker standards. The commenter cites a United Nations effort to develop a 

global legally binding instrument on mercury by the year 2013. 

Commenter 2867 also disagreed with the severity of industry projections regarding plant 

shutdowns and a lack of capacity resulting from implementation of the proposed rules. The 

commenter suggests that many facilities will be able to meet limits with closer review of raw 

materials or by implementing less-expensive dust shuttling. In addition, it is possible for the 

industry to mitigate the claimed impact by encouraging cement equipment designers to tackle 

these issues and disseminating successful mercury reduction techniques throughout the industry.

Response: As noted in the preamble, EPA carefully considered the possibility of creating 

different subcategories of cement kilns with respect to mercury emissions, including 

subcategories based on the mercury concentration of the limestone. For the reasons stated in the 

preamble, we decided not to create this type of subcategory. We anticipate an increase in 

imports of only10 percent in 2013, which translates to a decrease in domestic revenues of 3 

million metric tons. 
103

The preamble also notes that EPA is forbidden by law from considering costs in determining 

MACT floors. NRDC v. EPA, 489 F. 3d 1364, 1376 (D.C. Cir. 2007); National Lime, 233 F. 3d 

at 640. Although one of the overall goals of the Act is to protect and enhance the quality of the 

Nation’s air and resources so as to promote the public health and welfare and the productive 

capacity of the population,” CAA section 101(b)(1), this overall goal does not somehow 

authorize EPA to adopt floors that either consider costs (overall or otherwise) or to base floors on 

other than what best performers achieve. Further information about the economic impacts of this 

rule can be found in the preamble and the project docket.

Wasting CKD to reduce mercury emissions

Comment: Several commenters (2144, 2824, and 2845) commented on the practice of shuttling 

or wasting CKD and its ability to reduce mercury emissions. 

Commenter 2845 stated that EPA should not consider the removal, or wasting of CKD a form of 

mercury control, nor should it be considered akin to a mercury control device. The purpose of 

wasting CKD is to ensure product quality. No plant wastes CKD with the intent of reducing 

emissions. The level of mercury removed by wasting CKD also varies significantly from plant to 

plant; to consider this practice as a form of mercury control is highly questionable. Furthermore, 

as EPA recognizes, wasting CKD generates solid waste, and cement companies often have 

significantly reduced their solid waste generation by decreasing their wasting of CKD. 

Accordingly, the Proposal should not require companies to waste CKD or engage in dust 

shuttling.

Commenter 2845 stated there are other limitations to reducing mercury emissions by removing 

or wasting baghouse dust. Instead of returning the dust (i.e., uncalcined limestone), it can be 

continually bled off to the finish mill and intermixed with cement. This is known as dust 

shuttling. However, there are limitations to how much of this baghouse dust can be intermixed 

with cement. Specifications on the quality of cement limit the amount of baghouse dust that can 

be intermixed with cement. Dust shuttling also results in additional carbon dioxide emissions 

from each ton of cement produced because companies cannot utilize limestone addition (the dust 

would use up all the insoluble residue and/or loss on ignition available). The commenter includes 

expanded comments on this topic as an appendix entitled Mercury Emission Control by 

Removing Baghouse Dust.

Commenter 2144 disagreed with the reference at page 21150 of the FR Notice that removal of all 

baghouse dust when the raw mill is down will yield only 4% reduction in mercury emissions. 

The commenter states that mercury control is actually negative during the raw mill-off condition 

considering a plant-wide material balance.

Commenter 2144 agrees with EPA’s statement that the use of CKD wasting to reduce mercury

emissions is site specific. The commenter added that with the construction specifications 

allowing 5 percent inorganic processing additions, the CKD or filter dust will often not need to 

be wasted and has been shown to improve or least not to degrade the cement in areas where the 

raw materials are low in alkali.
104

One commenter (2824) stated that criteria for determining the best-performing 12 percent of 

existing sources for mercury emissions should either not include kilns wasting CKD and 

scrubber dust or the contribution in the dust should not be subtracted from the input. Otherwise, 

depositing high mercury waste in landfills is considered best-performing. Wasting dust requires 

more fuel and feed which generates increased CO2 emissions. This is an adverse cross-media 

impact.

Response: The commenter is not correct in implying that intent is relevant in determining if an 

activity which affects emissions can be considered as a means of control. All that matters is the 

effect on emissions. National Lime II, 233 F. 3d at 640. We realize that this is a site-specific 

issue, and the percent removal obtained by shuttling or wasting CKD ranges from very low to up 

to 80 percent. Some of the best-performing kilns in the MACT floor waste CKD. It will take 

more extreme facts than those presented here to justify invalidating a practice that removes 

emissions from some of the best performers.

Comment: One commenter (2844) stated that there is no demonstrated ACI system that will 

simultaneously control mercury and hydrocarbons. In light of that uncertainty, the industry is 

faced with taking a chance on an unproven technology or using multiple technologies (ACI plus 

a scrubber plus an RTO) that represent huge investments which have not been analyzed fully by 

EPA.

Response: The reason EPA has long adopted the interpretation that the existing and new source 

MACT floors are to be applied on a HAP-by-HAP basis are that a whole plant approach likely 

yields least common denominator floors, that is floors reflecting mediocre or no control, rather 

than performance which is the average of what best performers have achieved. See the preamble 

to the final rule for more discussion.

Concerns over effectiveness of control technology

Many comments were received on the limited emission reductions achievable with the 

installation of add-on control devices.

Effects of mercury speciation

Comment: One commenter (2844) stated that the standards are not achievable, and EPA has 

used unrealistic assumptions about the control effectiveness of individual technologies. Wet 

scrubbers are ineffective controls for elemental mercury, and the effectiveness of ACI is a 

function of mercury speciation. In the utility industry, the collection efficiency ranges from less 

than 20 percent to greater than 90 percent. If the concentration of oxidizing agents is low, a high 

percentage of the elemental mercury is not effectively captured by the sorbent. There have been 

only limited mercury speciation data collected at cement plants, but what data there are indicates 

the mercury speciation at the inlet of the particulate control device ranged from almost 100 

percent to near 0 percent elemental mercury. Depending on plant configuration and flue gas 

composition, standard ACI will not provide a sufficiently high level of mercury control to allow 

certain cement kilns to meet the proposed rule. The cost of ACI is high, and may not be cost 

effective for facilities where the pre-control emissions are very small, and the emission reduction 

will be small.
105

Response: We set the standards based on what has been achieved in practice in the industry, 

with MACT floors established based on actual emissions data for the best-performing sources.

We used statistical analysis and a 30-day averaging period to account for variability, such as the 

situations cited by the commenter.

Activated carbon injection

Comment: One commenter (2845) stated that EPA overestimates the emission reductions from 

mercury controls. EPA states that most if not all cement facilities will have to install some form 

of mercury control in order to meet the proposed mercury rule. Currently, the best available 

control technology for mercury is considered to be ACI. However, the commenter argues that the 

effectiveness of ACI is site-specific, based on utility industry studies and that should be the case 

for the cement industry as well. The commenter provides discussion about the technical issues 

surrounding the five primary factors that affect mercury collection efficiency using ACI:

mercury speciation; temperature profile; residence time of the particulate control device; type of 

ACI used; and flue gas composition (particularly sulfur trioxide (SO3)).

Commenter 2845 stated that the effectiveness of ACI for mercury control, based on limited 

mercury speciation data, will be very site-specific. It also appears that the concentrations of 

elemental and oxidized mercury are very site-specific. As a result, as has been recognized in the 

utility industry, ACI is not the magic bullet that will always control mercury at a high level. 

Mercury control strategies will need to be tailored for each plant. Such strategies may include 

one or more of the following: installation of a polishing baghouse; use of treated carbons or 

enhancement agents; change in the strategies for handling of CKD (wasting or not wasting); 

installation of a wet scrubber; evaluation and testing of more experimental types of mercury

control technologies.

According to commenter 2845, all of these strategies will be expensive, and there is no guarantee 

that ACI or any configuration will be adequate to demonstrate compliance with the proposed 

mercury limit for a significant number of cement facilities. 

Commenter 2845 stated that EPA does not consider the adverse impact that ACI will have on the 

way CKD is handled by the cement industry. Industry has been striving to utilize CKD by either 

returning the CKD to the cement kiln, or beneficially utilizing it. To ensure the quality of CKD 

and to maintain the ability to recycle the CKD back to the system, it may be necessary to install a 

polishing baghouse. The polishing baghouse would introduce new problems, including lower 

than expected air-to-cloth ratios resulting in a larger footprint, self-ignition in the baghouse 

hoppers, and an increase in fugitive emissions, all of which increase installation and operating 

costs.

Response: The pilot test data we have available for ACI systems showed mercury removal of 90 

percent, and we conservatively used 80 percent removal in our analysis. We considered the 

installation of a polishing baghouse and included it in our analysis, as well as the use of a wet 

scrubber. The standards do not require that facilities install a particular type of emission control 

(e.g., ACI). Facilities will need to decide for themselves which control strategy is best for them, 

that will account for site-specific factors and allow them to obtain the level of emissions control 

needed to meet the numerical standard. Furthermore, we do believe that the test data from the 
106

electric utilities industry is transferable to this industry and that the commenters have not 

provided any technical basis for their comments other than a discussion of potential issues. EPA 

knows of nothing that would preclude these technologies from operating effectively in sequence. 

Wet scrubbers

Comment: Several commenters (2844, 2845, and 2900) stated that EPA did not fully consider 

the issue for wet scrubbers and mercury capture. Commenter 2845 worked with EPA in 2008 to 

study mercury reductions achievable through wet scrubbers, and includes the report in their 

comment.

According to commenters 2844, 2845, and 2900, the only mercury captured by a wet scrubber is 

oxidized mercury. Elemental mercury is insoluble in water and, therefore, passes through the 

scrubber. Therefore, the effectiveness of wet scrubbers for mercury removal is almost entirely

based on the form of mercury entering the unit. There is a wide range in mercury speciation for 

the cement industry. As a result, the theoretical level of mercury control obtained by already 

having or installing a wet scrubber will be different for each plant. There is also a phenomenon, 

known as mercury reemission, related to mercury/scrubber chemistry that may reduce the 

effectiveness of a wet scrubber to capture even oxidized mercury. Reemission is a result of 

mercury reduction chemistry in wet scrubbers, where oxidized mercury is reduced to insoluble 

elemental mercury. Mercury reemission is primarily a result of sulfate/sulfite chemistry. Testing 

conducted at four cement kilns utilizing a wet scrubber revealed that all four of the plants tested 

showed elemental mercury concentrations at the outlet of the scrubber to be greater than the inlet 

concentrations. Commenter 2845 stated that the pH in the scrubber may affect reemission and 

data as to the impact of pH on reemission are very limited and appear to be conflicting. 

According to commenters 2844, 2845, and 2900, EPA states that oxidized mercury will be 

captured by the scrubber but, as has been found both in the utility and cement industries, 

depending on the flue gas composition and type of scrubber, this is not always the case. To make 

any blanket statement as to the effectiveness of wet scrubbers to control mercury would be 

premature and site-specific. There are proprietary additive technologies that are available from 

companies such as Babcock & Wilcox which may help mitigate this problem but will result in 

increased costs. It should be noted that none of these additive technologies have been or are 

currently being utilized or even tested in the cement industry. Therefore, the effectiveness of 

these additives for the cement industry is unknown. Also, these additive technologies are not 

relevant for use in establishing the existing source floor because no such database for the use of 

this type of technology exists. 

Commenter 2900 provided data from two stack tests, in order to show the difficulty of achieving 

compliance with the new mercury limits, and the variability in run to run emissions during stack 

testing. 

Commenters 2833 and 2840 stated that EPA’s analysis has not identified add-on technology

within existing kilns that is effective for all forms of mercury. Only 3 of the 5 existing cement 

kilns equipped with wet scrubbers are among the 11 lowest mercury-emitting kilns, primarily 

due to low mercury concentrations in the limestone. One of the kilns equipped with a wet 

scrubber provided no mercury control at all. 
107

Commenter 2863 stated that several approaches to reduce mercury emissions had been 

considered at the commenter’s site:

Reduction of limestone mercury content by selective mining. The commenter provided mining 

data showing the variability and lack of predictability of mercury content in the commenter’s 

limestone quarry.

The addition of a wet scrubber to the commenter’s ACI system. The commenter notes that wet 

scrubbers only control oxidized mercury as elemental mercury is not water soluble. Given that

testing at the commenter’s kiln indicated that up to 70 percent of the mercury is in the elemental 

form, a wet scrubber is not going to provide a material amount of additional control. The ACI 

system is predicted to control high levels of the oxidized mercury as well as promote the 

oxidation of the elemental mercury. Therefore, no material additive benefit would come from the 

use of a wet scrubber.

A potential small boost in control efficiency may be obtained by bleeding a percentage of the 

dust collected in the primary baghouse into the finished product. The concept behind dust 

shuttling is that a percentage of the uncalcined limestone caught in the primary baghouse, and the 

mercury condensed on it, is continually bled off to the finish mill rather than the raw mill, and 

intermixed with cement. The usefulness of this procedure is limited by the commenter’s 

product’s performance standards. 

Another conceptual possibility for reducing mercury emissions from affected sources that 

include quarries with elevated mercury levels is to implement some sort of limestone scrubbing. 

The commenter is not aware of any commercially available systems that could reduce limestone 

mercury content.

Response: For mercury control, ACI systems are the most likely control, not wet scrubbers. Our 

analysis did not rely on wet scrubbers as the primary control for mercury emissions. In cases 

where wet scrubbers are used for HCl control, the scrubber may provide additional control for 

mercury. Wet scrubbers may also be helpful in reducing mercury emissions for a couple of highemitting kilns. We recognize the usefulness of dust shuttling as a method of mercury control is 

site-specific, but it is one of the control strategies to be considered.

Support mercury control strategies

Comment: Several commenters (2144, 2786, 2867, and 2928) provided comments in support of 

EPA’s assessment of the use of add-on controls and other methods to reduce mercury emissions.

Commenter 2867 provided discussion of several instances of the use of dust shuttling, ACI, wet 

scrubbers, and other Mercury control strategies. The commenter recommends that EPA:

 Help foster actual demonstrations of filter dust shuttling with temperature management. 

 Help foster the demonstration of catalytic oxidation or oxidant injection to make mercury

more collectable. 

 Help foster demonstrations of ACI or lime injection with dust shuttling and temperature 

control and determine ways to make this combination less expensive.
108

Commenter 2928 supported the use of ACI for mercury control saying that it has a long 

commercial track record in removing mercury from emissions of coal-fired power plants and 

waste-burning facilities. 

Commenter 2928 provided information about a German cement manufacturer’s patent for an 

ACI system based on powdered furnace coke, coupled with dust withdrawal/shuttling, 

temperature control, and mercury oxidation by sulfur doping. 

Commenter 2928 stated that the use of selective catalytic reduction (SCR) in combination with 

scrubbers for removal of mercury is a technically feasible and economically reasonable control 

technology for cement plants. The commenter noted that the 2006 Assessment of NOx Emissions 

Reduction Strategies for Cement kilns – Ellis County written by five cement industry experts for 

the Texas Commission on Environmental Quality concluded SCR was an available technology

for newer dry kilns and a transferable technology, for older wet kilns, meaning it is 

commercially available and could reasonably be expected to work on those wet kilns. 

Commenter 2144 recommended that EPA foster the demonstration of catalytic oxidation or 

oxidant injection to make Mercury more collectable. Technologies include SCR and potentially

peroxide injection into gas conditioning towers. The commenter has data demonstrating the 

efficacy of mercury reduction in the coal-fueled power industry when SCR is used to control 

NOx emissions. SCR technology has been commercially demonstrated in the cement industry at 

Solnhofen, Germany, Monselice, Italy and Sarche di Calavino, Italy. It has excellent multipollutant possibilities including reduction of THC and dioxin/furan (another HAP regulated 

under the Cement MACT rule). The commenter provided an internet link to a report evaluating 

the use of SCR in the cement industry.

Commenter 2928 stated that the use of scrubbers technically feasible and economically 

reasonable control technology for mercury removal from cement plant emissions. 

Commenter 2928 stated that the use of front end controls can also be used to control mercury 

emissions. Technology that removes mercury from coal that is being fired for fuel increases the 

efficiency of the coal by 30 to 50 percent, reduces mercury by up to 70 percent, and decreases 

SOx and NOx. 

Commenter 2786 stated that it is possible to achieve mercury reductions in a cost effective 

manner, citing the Maryland Department of the Environment’s agreement with Lehigh Cement 

Company at their Carroll County facility to reduce emissions by 80 percent by 2012. 

Commenter 2142 stated support for EPA’s focus on good particulate control as a way to achieve 

good mercury control. The commenter provided two summary tables of mercury emission 

reductions by non-cement source categories and stack test results for mercury emissions from 

coal-fired power plants. 

Response: EPA acknowledges the support of the commenters of EPA’s assessment of the use of 

add-on controls and other methods to reduce mercury emissions and agrees that many of the 

suggested control methods are cost effective for various installations. However, we should note 

that MACT standards must be based on the best-performing sources in the category or 

subcategory, not a specific control technology. 
109

Increased CKD waste as result of mercury control strategies

Comment: One commenter (2898) suggested that EPA address the potential increase in cement 

kiln dust waste or reuse. EPA discusses the potential for an increase in the amount of CKD 

wasting at cement plants as a result of mercury emissions control practices. 74 FR at 21165. 

However, the status of CKD that is not reused in the production process is uncertain. EPA has 

yet to establish standards for the management of cement kiln dust. EPA last published a Notice 

of Data Availability concerning cement kiln dust in July 2002 and intimated that it would 

propose new standards for the management of CKD, but has taken no further action on the 

subject. In light of the potential for increase in the practice of CKD wasting and the uncertainty 

surrounding the treatment of CKD, the commenter urged EPA to consider adding requirements 

to the rule to prevent or control the potential additional solid waste or to initiate a separate 

rulemaking to address the proper handling of CKD.

Response: EPA is making no determinations as to the status of waste generated as a result of this 

rule, nor making any determinations as to management practices for cement kiln dust. In

assessing the costs of the rule for purposes of EO 12866, EPA has conservatively assumed that

wastes will be landfilled and estimated the costs of doing so as part of the estimated costs of the 

rule.

Mercury standards not supported on public health basis

Comment: One commenter (3067) stated that EPA’s public health basis for the proposed 

mercury requirements was not scientifically supported. The commenter requested that EPA 

provide information about: what percent of methyl mercury that is consumed by fish comes from 

cement plants; how much of the industrial contribution of mercury is converted to methyl 

mercury in soil; if there are studies suggesting that lowering mercury emissions would lower 

methyl mercury levels in fish; and EPA’s supporting evidence that these rules provide health 

benefits.

Response: According to the 2005 National Emissions Inventory, mercury emissions from 

cement kilns represent 18% of the industrial (non-electrical generating units) mercury inventory

in the U.S. (U.S. EPA, 2005). This final rule would reduce mercury emissions from cement kilns 

by a substantial amount. The rate of mercury methylation is spatially variable, depending on the 

specific aquatic chemistry of the deposition location.

For this final rule, EPA modeled mercury deposition from cement facilities using the 

Comprehensive Air Quality Model with extensions (CAMx) model. This model converted 

mercury emissions to ambient mercury levels and mercury deposition. In the final RIA, EPA 

provides maps of the reduced mercury deposition. Due to time and resource limitations, EPA 

was unable to model the conversion from mercury deposition to methylmercury to human health 

effects from consuming methylmercury-containing fish. For more information regarding the 

health effects from mercury, please consult EPA’s mercury website at http://www.epa.gov/hg/.

However, EPA notes that standards under section 112 (d) are technology-based, not risk-based.

Thus, the decisions as to the level of the standards is based entirely on the criteria set out in 

sections 112 (d)(3) and (d) (2), which do not include consideration of risk. EPA did take into 
110

account that mercury is a potent neurotoxin, and the magnitude of mercury emissions from 

particular cement kiln sources, in determining not to create a subcategory for high mercury

emitting sources with high concentrations of mercury in their limestone. EPA believes it 

legitimate to consider these factors in determining whether to exercise its discretion whether or 

not to exercise subcategorization authority, since these factors relate to the ultimate object of 

section 112 (d) of reducing emissions of hazardous air pollutants.

Least cost control options may not yield expected SO2 emission reductions

Comment: One commenter (2144) provided links to state air agency and trade group 

presentations regarding control options. The commenter noted that cement companies will 

gravitate to the least-cost options and it is not a given they will choose mercury or HCl reduction 

strategies that will actually yield the magnitude of reductions expected by EPA in SO2, a 

pollutant not regulated under §112.

Response: EPA recognizes that any SO2 emission reduction obtained as a result of this NESHAP 

rulemaking is a co-benefit of the control technology selected either for Hg or HCl. EPA 

recognizes the multi pollutant interactions and co-benefits of this rulemaking and how a well 

planned integrated control strategy can maximize the environmental results while optimizing the 

cost invested by a facility to comply with such regulation. 

Restrict use of quarries with high mercury limestone

Comment: One commenter (2893) recommended that EPA should not allow any new high 

mercury content limestone quarries to be mined, and that no new high mercury content limestone 

quarries be allowed to be mined at kiln locations in which an old limestone quarry has been 

mined out. 

Response: The new source standard for mercury reflects the performance of the best controlled 

existing kiln. If a new kiln locates at a quarry with high mercury levels but can still meet this 

limit, they are allowed to do so under section 112 (d).

2.6 THC Standards 

Comment: Several commenters (2898, 2928) recommended that EPA adopt the proposed 

MACT floor for THC. 

Response: EPA has revised the proposed THC floor and standard based on more representative 

data. See “Development of the MACT Floors for the final NESHAP for Portland Cement”.

2.6.1 Legal Issues

Use of CEMS data results in unlawful standard

Comment: One commenter (2901) stated that basing the THC on CEMs data leads to an 

unlawful standard. The commenter’s concerns are that:

 Using daily averages significantly reduces variability, leading to an unlawful standard.
111

 There is a flaw in using continuous data under normal operating conditions to set a 

standard. 

 The currently proposed 7 ppmv THC standard cannot be achieved by the top performers. 

The commenter provided an analysis based on the daily data for two sources that EPA 

used to set the floor, resulting in one facility not meeting the standard 20 percent of the 

time.

Response: The standard in the final rule has been revised from proposal based on additional 

data. However, all of the data on which the standard is based comes from CEMs, so there is no 

basis for stating that use of a CEM makes the standard more stringent. The data also are gathered 

from periods of well over a year, and so can reliably be used to assess monthly variability

without use of statistical extrapolation.

Unlawful rescission of standards for Greenfield sources

Comment: One commenter (2864) stated that EPA is unlawfully attempting to rescind the THC 

standards for greenfield sources in the proposed rule. EPA established MACT standards over 10 

years ago when it first promulgated the NESHAP for the cement industry. 64 FR 31898 (June 14, 

1999). The commenter stated that EPA may revise MACT standards under two provisions: 

§§112(d)(6) and 112(f). EPA has not undertaken the necessary analysis under either provision to 

conclude that new greenfield sources should become subject to either of the THC standards EPA 

has proposed.

Response: As noted in the preamble to the final rule in connection with EPA’s decision to 

amend the PM standard, EPA does not read section 112 (d)(6) as the exclusive means of 

amending a MACT standard, particularly when that standard does not properly represent MACT.

The standard was based on siting considerations only, and did not consider THC emission levels 

of the best controlled similar source as required by law. The standard is now anomalously higher 

than the existing source standard, confirming that it does not represent a proper MACT standard.

EPA therefore sees no bar to amending it to establish a standard properly based on section 112 

(d).

2.6.2 Adequacy of Floor Determinations (Existing and New)

5 best performing sources vs 12 percent

Comment: One commenter (2911) stated that EPA correctly based its THC floor on the 2 best 

performing sources.

Response: We agree that a literal reading of the stature results in a floor based on the two best 

performing sources based on the THC CEM data available at proposal

Comment: Many comments were received on the adequacy of the data and the analysis used in 

the development of the MACT floor for THC.

Commenters 2841, 2858, 2859, 2863, 2864, and 2889 stated that EPA’s use of 2 kilns as the 

basis for the THC limit for existing sources was inappropriate. The commenters stated that EPA 

should not set the THC MACT floor for existing cement plants using data from less than five 
112

sources. According to the commenter, EPA proposed to use the limited data set for two kilns due 

to a very narrow interpretation of §112(d)(3). Because there are more than 30 sources in the 

source category and EPA only has THC data for 14 kilns, it is apparent that EPA seized on the 

parenthetical part of the language in §112(d)(3)(A) to conclude that it can set the THC MACT 

floor based on only two kilns (12 percent of 14). According to the commenter, EPA made no 

attempt to use its authority under §114 of the CAA to require cement plants to monitor their 

emissions of THC in order to provide EPA with sufficient data to establish the MACT floors 

based on the best performing 12 percent of sources in the category. Congress clearly intended for 

EPA to obtain data from an adequate number of sources to be able to set realistic and achievable 

standards. Some of this commenter’s facilities comprised a significant part of the THC MACT 

floor yet the proposed standards are not achievable for most of the kilns owned by the company

without the installation of expensive controls such as regenerative thermal oxidizers (RTO) to 

control THC emissions. 

Response: EPA and the industry agree that it is most appropriate to use THC CEM data to set 

the floor because this data provided the most representative information on long term emissions 

performance. EPA made a concerted effort to obtain additional THC CEM data subsequent to 

proposal of this rule. Unfortunately, the data was received too late in the process to be 

thoroughly analyzed. In addition, the use of this additional data would not have substantially 

changed the outcome of the floor determination for most kilns. We continue to believe that the 

literal reading of the statute required us to use the best performing 12 percent of the facilities of 

which we have emissions data, which, in this case, is two kilns.

Variability incorrectly analyzed

Comment: Commenter 2864 stated that EPA incorrectly analyzed variability in calculating the 

proposed THC MACT floor. The commenter stated that CEMS data cannot account for all of the 

long-term variation in a given quarry, which extends over several hundred acres with a life of 

over 100 years. The commenter stated that EPA’s analysis using 30 days of data results in a 

MACT floor that cannot be achieved over the long-term. EPA must identify a MACT floor for 

each HAP and source category based on emission levels achieved by the best-performing 12 

percent of existing sources, and must demonstrate with substantial evidence that the chosen 

floors represent a reasonable estimate of the performance of the best-performing units. EPA’s 

use of the UPL model to calculate the MACT floors for THC violates this requirement because it 

does not represent a reasonable estimate of the performance of the best performing sources.

Commenter 2864 also critiqued EPA’s method for calculating variability, and provided an 

alternative calculation after collecting additional long-term data for the lowest emitting five 

sources. The commenter stated that the UTL provides a much better estimate of the 99th 

percentile adjusted for variability than the UPL. The commenter stated that EPA should have 

used the actual 99th percentile to establish a MACT floor because the data set contains long-term 

data. 

Commenter 2889 requested that EPA review the additional data from the recent §114 request or 

provide detailed information that demonstrates that the 11 kilns for which data are available do, 

in fact, represent the entire cement industry.
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Commenters 2841, 2845, 2858, 2859, 2863, 2874, and 2889 stated that EPA relied upon a data 

set that included a combination of long-term (470-880 data points) and short-term (31-35 data 

points) CEMS data, from 12 kilns. This resulted in data from the two lowest emitters being used 

to establish the existing MACT floor. One of the two sources used in the floor calculation had 

only 35 data points, or the equivalent of six 30-day rolling averages. To compensate for this lack 

of data, EPA used the UPL statistical approach to project long-term variability. EPA is now in 

possession of more than one year of CEMS data for 16 kilns. While this still represents a rather 

small portion of the entire cement industry, the commenters agreed that it is a statistically

representative database for purposes of setting existing and new source floors. In addition, the 

commenters recommend that EPA use the calculation of the 99th percentile rather than the UPL

to establish the MACT floor levels. 

Commenters 2859, 2845, 2863, and 2874 stated that with the additional THC CEM data 

provided to EPA since proposal, EPA now has a sufficient amount of data and may not need to 

apply any statistical analysis to account for variability and simply use the available emissions 

data. However, given the new data and considering that the new data sets account for variability

in the 5 best performing sources, the revised THC standard should be 27 ppmv dry at 7 percent 

oxygen for existing sources and 24 ppmv dry at 7 percent oxygen for new sources. However, the 

data does not show whether the limestone reserves available to units in the existing data pool or 

other units have significant variations in the nature and amount of organics. Furthermore, where 

either coal mill and/or raw material dryer exhaust are co-mingled with the kiln stack emissions, it 

is important to determine whether either case warrants subcategorization. Although the PM 

standard in the proposed NESHAP was based on a limited data set of 3-hour stack tests, shortterm test will not address the variability issues. Commenter 2874 stated that EPA should base the 

THC standard on substantially more data.

Response: In response to comments, we re-evaluated the statistical analysis and methodology

used for the proposed rule and made changes to improve it. The changes we made and why are 

discussed in the preamble to the final rule and in supporting documentation in the docket and 

include why we continue to believe the use of the 99th percentile UPL is the most appropriate 

statistical approach, how we accounted for variability (including intra-quarry variability), and 

other changes to the analysis since proposal. We disagree with the commenters who said 30 days 

of data are insufficient, and we continue to believe that the 30 data points provided from 30 days 

of sampling of all kiln inputs for 89 kilns is a robust sample of the population of cement kilns 

and adequate to characterize the variability encountered at each individual kiln, especially as 

supplemented in the final rule to account for documented inputs from outside the 30-day

sampling period and with pooled estimates of intra-quarry mercury variability (both of which are 

then put into the UPL equation as part of the s squared term).

Subcategorization

Comment: Many commenters (2844, 2845, 2859, 2863, 2864, and 2874) suggested that EPA 

consider subcategorization due to the variations that can be found in raw materials, source 

configurations, and processes in which the current data from the 5 best performing sources does 

not accurately illustrate how emissions may vary in different kiln configurations and other 

sources. Commenter 2864 urged EPA to collect data from all cement plants in order to properly
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subcategorize, and delay setting THC MACT standards until that time. The commenters 

suggested that EPA gather long-term THC CEMS emission data for the following reasons:

 For some kilns, high THC levels can be attributed to a combination of the level of 

organics in the limestone, the form of the organics in the limestone, and a kiln 

configuration that has one or more source of organic releases downstream of the kiln (in 

particular in-line raw mills and in-line coal mills venting to the main stack.). While a few 

of the units with THC CEMS have high THC emissions, the data on raw material (e.g., 

limestone organics) have not been collected or correlated for these kiln emissions. 

Commenter 2845 submitted a white paper (Appendix 9) addressing these issues as part of 

their comment.

 EPA has assumed that any raw material dryers should meet the kiln THC limit; however, 

EPA has no data to show that this is an appropriate extension of kiln THC measurements. 

There are limited data that suggests that these dryers have lower volume and higher THC 

emissions than kilns.

 Separate standards for standalone raw mills operated with supplemental fuel firing, raw 

material dryers, and those kilns with high THC levels due to organics in the co-located 

quarry may be appropriate. This cannot be done without a strong database of THC CEMS 

readings and feed material characteristics supporting the best possible presentation on the 

need for one or more added subcategories for THC limits.

 There is no data to suggest that organic HAP at standalone raw mills that use 

supplemental fuels and coal mills that use kiln or cooler gases are emitted.

 The proposed organic HAP standards did not account for the various volatiles that are 

added to the kiln exhaust as a result of contract with the ground coal in a coal mill. 

Commenter 2863 testing documented that a considerable quantity of organics are added 

to the stack exhaust when the kiln gases are routed through the coal mill. Although, the 

majority of the organics are methane, the non-methane, non-ethane hydrocarbon, and the 

total hydrocarbon emissions exceeded 100 ppmvd on average.

 EPA should consider collecting additional data to determine if subcategorization is 

appropriate to address THC emission variability from different physical characteristic of 

kilns or different characteristics of raw materials.

Response: See preamble to final rule.

Background THC levels not accounted for

Comment: One commenter (2889) stated that EPA has not taken into account ambient 

background THC levels and the variability in ambient background THC levels that inherently 

affect measured stack concentrations. Ambient levels of methane and ethane will increase the 

measured THC by as much as 15 percent. The commenter stated that additional data are needed 

concerning the multi-day and multi-week increases in ambient air THC levels due to forest and 

agricultural fires.

Response: We disagree with the commenter in that the MACT floor determinations were based 

on demonstrated performance testing and THC monitoring from several plants over extended 
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time periods. These long-term monitoring test data included ambient background THC levels and 

their associated variability.

THC standards are adequate

Comment: One commenter (2144) stated that the proposed 30-day emission standards of 7 and 

6 ppm for existing and new kilns, respectively, appear to be adequate. These values equate to 

roughly half of the BACT VOC limits when relying on THC as the surrogate. According to the 

commenter, at many kilns the primary contributors to THC emissions are additives acquired as 

wastes from other industrial sources such as steel mill scale. Excessive VOC/THC emissions 

problems in Florida were typically solved by acquisition of less oily mill scale. Another solution 

is to introduce the oily additives directly into the kiln system where they can be thoroughly

burned thus avoiding low and medium temperature THC evolution from colder parts of kilns and 

preheaters. This commenter agreed with EPA regarding regenerative thermal oxidation (RTO) or 

ACI particularly when naturally existing kerogen in native raw materials contributes to THC 

emissions. The commenter also noted that the Polysius Environmental Technology (POLVITEC) 

available since the early 1990’s includes a coke filter that has been demonstrated to reduce THC 

and SO2 while storing mercury until it can be removed to a very high degree by filter dust 

shuttling.

Response: See the preamble to the final rule explaining the basis for the final THC standard.

Shorter averaging period

Comment: One commenter (2142) supported a shorter averaging time (24 hours or less) with 

regard to hydrocarbon emissions, but agreed with EPA’s proposed limits and 30-day averaging 

time.

Response: EPA acknowledges the commenter’s support.

POM and naphthalene not adequately addressed

Comment: One commenter (2828) expressed concern that the proposed MACT rules do not 

establish MACT limits or properly evaluate control technologies that could greatly reduce 

emissions of polycyclic organic matter (POM) , naphthalene, or dioxins/furans. The commenter 

agreed with EPA that limits should be established for organic hazardous air pollutants, and the 

choice of VOC or total non-methane hydrocarbons (TNMHC) seem like reasonable options as 

surrogates, but emissions of POM and naphthalene are likely to be unrelated to emissions of the 

other organic HAPs. The commenter stated that traditional organic HAPs are primarily driven by 

hydrocarbons in the raw material mix. Variations in the hydrocarbon composition of the 

limestone seemed to be the largest contributor to variability in organic HAP and THC emissions.

Because the processes resulting in POM and naphthalene formation are not the same as those 

resulting in VOC or benzene, toluene, ethylbenzene, and xylene (BTEX) compounds, cement 

kilns that are low VOC and BTEX compound emitters may be high emitters of POM and 

naphthalene. The commenter encouraged EPA to move forward with establishing final MACT 

rules proposed in this rulemaking, including rules for organic HAPs, but suggested that EPA 

consider the difference in the formation mechanisms when deciding how to establish MACT 
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standards for all organic compounds, and potentially separate POM and naphthalene from the 

other organic compounds in establishing MACT standards and appropriate monitoring protocols. 

Further, EPA should undertake additional study of POM and naphthalene emission rates from 

cement kilns throughout the U.S., to determine if there is tight correlation between emissions of 

these compounds and the other organic HAPs. If not, EPA should then establish POM and 

naphthalene MACT standards, independently of the standards for the other organic HAP 

compounds.

Response: EPA reviewed test reports for emissions data on THC and organic HAP. Based on 

those test data, we identified specific organic HAP that were measured with sufficient frequency 

that we could and at levels that would allow us to establish an emission limit for organic HAP as 

an alternative to the THC limit. Naphthalene emissions were included in the analysis of organic 

HAP as an alternative to the limits for THC. It is regulated under the final rule in that the 

definition of organic HAP specifies naphthalene as one of the organic HAP that must be 

measured to determine compliance with the organic HAP limit. In evaluating emission test 

reports, the test results for POM were not sufficient to include as one of the organic HAP that 

must be measured. However, we believe that the limits for THC and organic HAP serve as 

surrogates for POM and that POM emissions will be reduced as a result.

Organic HAP alternative

Comment: Regarding the organic HAP alternative to THC, several commenters (2845, 2859, 

and 2874) stated that the organic HAP standards should be raised to reflect the commenter’s 

proposed THC standards of 27.4 ppmv and organic HAP standard of 6.6 ppmv (24 percent of 

27.4) for existing sources and 24 ppmv and organic HAP standard of 5.7 ppmv (24 percent of 

24) for new sources. 

Commenter 2863 stated that the proposed THC standard of 7 ppmvd for existing sources and 

6 ppmvd for new sources is inadequate and requested that EPA not revise the organic HAP 

standard until it has time to better evaluate existing data and that a separate subcategory for kiln 

exhaust gases passed through an indirect fired, inline coal mill. Also, the volatility of the coal 

being used should be considered in establishing standards for inline coal mills. As part of the 

final rule, EPA should include a specific exclusion for coal mills from coverage under subpart Y 

NSPS so plants will not have to deal with dual and potentially conflicting regulations

Commenters 2859, 2845, 2863, and 2874 objected to the option of demonstrating compliance 

with the alternative equivalent organic HAP emission limit rather than the THC limit for 

companies that have naturally low hydrocarbon emissions, very low organic HAP emissions, and 

use Method 320 to demonstrate organic HAP compliance for the following reasons:

 The organic HAP standard does not account for variability in THC levels when using 

Method 320 to demonstrate compliance. The organic HAP rate may be substantially

lower than the 2 ppm indicated in the proposed rule; however, the concurrent THC 

concentration levels may be substantially higher than the 6.7 ppm even if testing during 

typical conditions.

 Units should be permitted to extrapolate the same factor for organic HAP level and THC 

compliance limit set during the organic HAP compliance demonstration test.
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 As an alternative, kilns should be given an opportunity to establish and take into 

consideration THC variability before the THC limit is set during the organic HAP 

compliance demonstration test and be allowed the option to install CEMS before the 

organic HAP compliance demonstration test in which THC and organic HAP emission 

rates could be collected for 6 months prior to the demonstration test. The operator would 

have to demonstration that operating conditions are representative of the 6-month period 

at the time of the stack test and once the compliance is demonstrated EPA could set the 

application THC limit at 99 percent variability for that 6-month period for the unit.

 Facilities that choose to comply based on actual organic HAP should have the option to 

demonstrate compliance whenever THC emission exceeds the limit set during organic 

HAP compliance demonstration test because limestone deposits are not homogenous 

creating the possibility that new high THC seam might be encountered and thus raising 

the possibility that THC will go up but organic HAP emissions may remain constant. The 

facility should be given 6 months to retest for organic HAP if the alternative THC limit is 

exceeded and if the kin complied with the organic HAP limit, no violation should be 

found related to the high THC emissions.

Commenter 2844 recommended that EPA adopt the proposed THC compliance alternative for 

sources whose organic HAPs are a low percentage of their total THC. This compliance 

alternative is important for kilns whose THC emissions may be higher due to other factors but 

who have established that HAPs are a low percentage of those emissions. 

Commenter 2889 stated that EPA does not reference the study that provided the basis for the 

HAPS/THC ratio. Considering the importance of this alternative standard, this study should be 

cited. It should also be evaluated to determine if the 0.24 HAP/THC ratio is, in fact, 

representative of the cement industry. 

Response: See discussion of THC and organic HAP in the preamble.

Emission limits for raw material dryers

Comment: Several commenters (2845, 2859, 2863, 2874, and 2910) stated that it is 

inappropriate to set the same emission limits, and controls, for kilns and raw material dryers and 

that EPA establish MACT floors for new and existing sources of raw material dryers using data 

from the dryers. Cement kilns and raw material dryers differ in the following ways:

 The heat source in the kiln is designed to reach high temperatures for calcining and 

combing raw materials to make clinker; the heat source in the raw material dryer is 

designed to remove free water from the raw materials. of the heat source in the raw 

material dryer is for removing free water from the raw materials. Because the temperature 

within the kiln system and tower is above 600 degrees F, hydrocarbons present in the 

feed volatilize. In contrast, the temperature in a raw material dryer is significantly lower, 

resulting in a completely different profile of hydrocarbons volatilized.

 The volume of gasses drawn through kiln systems is 10 times greater than the volume of 

gasses passing through the raw material dryer.
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 The proposed THC limits for dryers expressed at 7 percent oxygen are equivalent to a 1 

ppm actual emission concentration standard at the material dryer. 

 Facilities may intermittently use raw material dryers. Commenter 2910 stated that the 

cost to install the required monitoring equipment and possible emissions control devices 

would prove to be more costly than EPA has assessed.

Based on the substantial differences between kilns and raw material dryers, there is no basis to 

simply assign the proposed kiln THC standard to raw material dryers. EPA should withdraw the 

limit and more closely evaluate actual raw material dryer emissions in order to confirm that these 

units generate organic HAPS to a level necessitating regulation and if they do establish the data 

necessary to support an appropriate limit. Commenter 2845 has initiated a process to gather 

additional THC emissions data, data to more thoroughly assess raw material dryer THC emission 

performance, and organic HAP data for standalone raw material dryers. These data will assist 

EPA is developing more appropriate standards.

Commenter 2845 stated that when defining the THC limit for raw material dryers at major 

sources in §63.1346(a), the proposed rule does not include the alternate option of complying with 

a total organic HAP limit. The commenter suggested that the language should be updated to 

reflect the same option as allowed in (b) for area sources.

Response: We did not have sufficient data, information, or justification to subcategorize raw 

material dryers as suggested by the commenter. We were working with a limited data set of kilns 

and dryers and the MACT floor is based on the performance of the two lowest emitting kilns.

The additional THC data was received too late to be considered in this rulemaking. These data 

were not submitted to EPA until mid-June 2010, virtually too late for any consideration, much 

less considered in the MACT floor analysis and subcategorization. 

Regarding the alternate total organic HAP limit for raw material dryers, we have corrected the 

final rule to state the alternate option of complying with a total organic HAP limit applies to raw 

material dryers at major and area sources.

Subcategorize based on coal grinding system

Comment: One commenter (3218) requested that EPA consider developing subcategories that 

reflect the different configurations for coal grinding systems. There are two main configurations, 

where gases are vented from the coal system directly to atmosphere out of a separate stack and 

where coal system gases are vented to atmosphere after being comingled with exhaust gases 

from the kiln and vented out of a common stack.

Response: EPA did consider subcategories based on the coal grinding configurations suggested 

by the commenter but decided against creating separate subcategories. See the preamble 

discussion under the THC limits for more information on EPA’s decision.
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2.6.4 Compliance Assurance

Relative accuracy test audit

Comment: One commenter (2622) stated that the PS included in the proposal for certifying the 

VOC monitor does not require a Relative Accuracy Test Audit (RATA). The proposal would 

also apply Appendix F to the VOC monitor, which requires annual RATA. There is an 

inconsistency in not requiring a RATA for certification, but requiring it annually after 

certification.

Since the proposal calls for RATA on the VOC monitors when the emission limits are low 

(emission limits less than 10 ppm), EPA will need to set a low emission criteria for passing a 

RATA. The commenter expressed concern that 20 percent of the reference method or 10 percent 

of the emission limit will be too restrictive.

Response: The final rule has been revised to require the certification of the CEMS using 

Performance Specification 8, which does require a Relative Accuracy Test Audit. The 

performance criteria have not been changed.

Monitoring at low concentrations

Comment: Several commenters (2844 and 2845) stated that monitoring THC at the 6-7 ppm 

level will present significant challenges, noting that hydrocarbon CEMS have been used 

successfully on hazardous waste burning kilns but at concentrations greater than three times 

those required by this proposed rule (i.e., 20 ppm). Furthermore, when a hazardous waste kiln 

approaches the limit of 20 ppm, it triggers an automatic waste fuel cut-off, which ensures that the 

facility is in compliance with the standard as there are no hazardous wastes in the combustion 

chamber under higher hydrocarbon concentrations. This approach will not be available for non 

hazardous-waste burning cement kilns as the THC concentration approaches or exceeds 6-7 ppm. 

EPA should raise the limit to account for the variability associated with the raw materials and the 

inability to change raw material input to comply with the standard. Once installed it is expected 

that the CEM up-time and data availability will be less than the 90 percent required by EPA due 

to the learning curve that will be associated with operating and maintaining these devices. The 

commenter stated that hot/wet straight extractive systems are difficult to maintain on a 

continuous basis due to moisture condensation in heated sampling systems, often long calibration 

times, and monitor wear and tear from the corrosive environment. Some of the challenges that 

will need to be addressed include: the difficulty of monitoring hydrocarbons at very low 

concentrations, the accuracy of calibration materials as 1 ppm propane standards are the lowest 

available, and the variability of hydrocarbon compounds in the limestone used to manufacture 

cement.

One commenter (2889) stated that the variability in flame ionization detectors (FID) response 

factors for organic compounds changes the stringency of the THC standard for some kilns. It is 

well known that THC monitors using FID have different response factors for different organic 

compounds. Cement kilns having organic compounds with a higher set of response factors will 

be subject to more stringent emission limits than kilns having organic compounds with lower 

response factors. Considering that there are very little data concerning the ranges of specific 
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organic compounds in the kiln effluent gas stream, the impact of the variations in response 

factors cannot be determined. Additional data are needed to determine if the THC standards of 6 

ppmvd (new kilns) and 7 ppmvd (existing kilns) is equitable.

Response: Based on data received since proposal, we have revised the THC limit to 24 ppmvd 

which should address the commenters’ concerns about monitoring at very low concentrations.

The standard is based on data from different kilns with different constituents, which addresses 

variability concerns. Finally, with the change to PS8, sources are not restricted to use of FID is 

they do not work as well as needed in certain applications.

Stack testing for monovent facilities

Comment: One commenter (2888) requested that EPA allow monovent facilities to stack test for 

THC, using EPA approved methods, on the same 30-month frequency as required for 

Dioxin/Furan testing under the current PC MACT.

Response: We remain convinced that CEMS are the best choice for continuous monitoring.

Sources with monovents can install stacks to accommodate their use.

Testing to comply with speciated organic HAP alternative standard

Comment: Several commenters (2844 and 2845) stated that the Fourier Transform Infrared 

Spectroscopy (FTIR) Method 320 and the American Society for Testing and Materials (ASTM) 

Test Method D6348 are not sufficiently sensitive to quantify the 1-2 ppm of total organic HAPs 

for companies wishing to speciate organic compounds. Because a single test method is not 

available for the organic compounds EPA has identified and because of the low concentration 

levels, EPA must be flexible in test method selection and allow use of appropriate methods to 

quantify and sum these compounds. It is anticipated that at least 3 separate test methods will be 

required to capture the low concentration of organic HAP to sum to 1 or 2 ppm aggregate. 

Response: As stated above, we have raised the level of the THC limit which should address 

concerns about low concentrations. We have carefully considered detection limits when setting 

the standards; a more detailed discussion of this issue is presented in the preamble.

Comment: One commenter (2844) stated that a THC alternative option must address THC 

variability for those units meeting the organic HAP alternative limit. The commenter 

recommends stack testing for organic HAPs at the same interval as that for dioxin/furans. Under 

the proposed rule, a new THC limit would apply based on the level at the time of the test. The 

commenter provided the following options for compliance demonstration limits, with the 

suggestion that a kiln operator would be able to choose between the three:

 Demonstration of operating conditions consistent with test conditions and good 

engineering practices. The ongoing compliance demonstration would be based on two 

operating conditions that are indicators of organic HAP emissions at the time of the stack 

test, with subsequent continuous monitoring of those two parameters: the temperature at 

the exit of the precalciner and the oxygen content of the exhaust at the top of the 

preheater. 
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 Extrapolation to set the revised THC limit. The revised THC limit is based on the total 

organic HAP measured during demonstration testing, extrapolated to the level of 

compliance and then extrapolating the average THC value recorded during the total 

organic HAP test to the proportionate level. 

 Accounting for measured THC variability when setting the revised THC limit. The kiln 

owner installs the THC CEMS in advance of the stack testing and gathers data for at least 

6 months prior to the stack test. At the time of the stack test, the operator must 

demonstrate that the operating conditions are consistent with that 6 month period. Once 

compliance is demonstrated, the applicable THC limit will be at the 99% of variability

for that 6 month period for that unit.

The commenter also suggested that if the alternative THC limit is exceeded, the operator should 

be given six months to retest for organic HAPs; if the organic HAPs are compliant in the retest, 

there is no violation related to the high THC reading.

Response: The MACT floor determinations were based on demonstrated performance testing 

and THC monitoring from several plants over extended time periods. These long-term 

monitoring test data included ambient background THC levels and their associated variability

Comment: One commenter (2845) stated that companies that have low hydrocarbon emissions 

and low organic HAP emissions may elect to demonstrate compliance with the speciated HAP 

portion of the rule and that a new THC limit would apply based on the level at the time of the 

test. However, because THC levels are variable, it could mean that 50 percent of the time the 

THC will be recorded over the limit even though the performance of the unit is unchanged. 

According to the commenter, there are at least 2 options, extrapolation or accounting for the 

THC variability, that could be used to show practical THC limits along with allowing the kiln 

operator to select the most appropriate option.

Response: Companies that elect to comply with the speciated HAP portion of the rule should 

collect any background or previous test information that would allow them to conduct their 

testing in a worst-case scenario for their particular operations. The issue described by the 

commenter is a key reason for having a 30-day compliance period – where any given day the 

measured levels will be above or below the average. Sources also have the option to retest if they

believe the previous testing was not representative.

Comment: One commenter (2844) requested that EPA defer promulgating a final THC standard 

until more adequate data has been gathered, but urged EPA to finalize the Alternative 

Compliance Option for THC as expeditiously as possible.

Response: EPA has gathered significantly more data since proposal and believes it ample to set 

the final standard.

Measuring THC from raw material dryer

Comment: One commenter (2845) stated that the process and combustion gas composition of 

the kiln system and dryer are completely different. In the kiln, the main constituents are nitrogen 

and carbon dioxide. Oxygen content of the kiln exhaust gas is typically below 2 percent at the 

kiln exit and about 7-10 percent at the stack. In the raw material dryer the main constituents are 
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nitrogen and oxygen, with oxygen levels typically above 19 percent. Also, if the THC 

concentration in the raw material dryer is adjusted to 7 percent oxygen as proposed for the kiln, it 

would require the actual emission concentration to be less than 1 ppmvd THC to meet the 

proposed limit of 7 ppmvd. The accuracy of the THC analyzers available for monitoring is not 

sufficient to determine compliance with a 1 ppm standard. (1ppm THC at 19 percent oxygen = 

7.3 ppm at 7 percent oxygen). Calibration gases are manufactured at a lower concentration of 1 

ppm propane, and demonstrating compliance at the level corresponding to the lowest level 

calibration standard generates an unknown degree of inaccuracy.

Response: We received no data indicating that using the same limit for raw material dryers as 

used for kilns was infeasible, or that it would otherwise allow us to set a different THC emissions 

limit for raw materials dryers. Therefore, in these final amendments we are setting the THC 

emissions limit at the same level as the cement kiln’s, which is 24 ppmvd measured as propane.

However, because raw material dryers have high oxygen contents due to their inherent operation 

characteristics (and not due to the addition of dilution air), referencing the raw material dryer 

standard to 7 percent oxygen would actually result in a more stringent standard than for cement 

kilns. For example, given the typical oxygen contents of kiln exhaust (7 to 12 percent), a kiln just 

meeting the THC limit of 24 ppmvd would have an actual stack measurement of approximately

16 to 24 ppmvd. If the raw material dryer standard is referenced to the same oxygen level, they 

would have to meet a measured THC limit of approximately 3 ppmvd. For this reason, we are 

referencing the oxygen level of the standard for raw materials dryers to 19 percent oxygen, 

which is the typical oxygen level found in the exhaust of these devices.

Flow rate monitoring

Comment: One commenter (2845) stated that EPA should not require volumetric flow rate 

demonstrations during speciated HAP or THC testing. The proposed standard is a concentration 

based standard, so no flow rate monitoring data are needed for reporting in units of the standard. 

At 40 CFR 63.1349(b)(4)(iv), EPA incorrectly requires that the flow monitoring system be 

evaluated according to procedures in Part 75, therefore this requirement should be deleted.

Response: The commenter identified an error in the proposed standard, which has been 

corrected in the final standard.

PS-8A

Comment: One commenter (2845) stated that PS-8A should be modified for low concentration 

measurements. PS-8A was developed for cement plants burning hazardous waste. PS-8A has an 

explicit span requirement of 100 ppm as propane. The calibration drift and calibration error 

requirements are 3 percent (3 ppm) and 5 percent (5 ppm) respectively, which are very near the 

proposed compliance level. The proposed THC standard is at 6 and 7 ppmv dry at 7 percent 

oxygen. The criteria contained in PS-8A will not evaluate the acceptability of the THC 

monitoring systems with adequate accuracy to demonstrate compliance with the proposed 

standard. Therefore, PS-8A must be completely re-worked to evaluate low concentration level 

monitoring systems, without simply (and arbitrarily) lowering the span and calibration drift 

specifications.
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Response: The final standard has been revised to specify use of PS-8, instead of PS-8A, because 

PS-8 is a better fit for this application. The span for the RATA is specified as 40 ppm and the 

reference method is established as EPA Method 25A. 

Need for Appendix F procedure

Comment: One commenter (2845) stated that EPA should develop an Appendix F Procedure 

specific for hydrocarbon CEMS. Although an Appendix F, Procedure 1 was written for SO2, 

NOx and diluent CEMS (O2, and CO2), it is not directly transferrable to a THC CEMS 

monitoring for compliance at extremely low concentration levels. For example, a key element of 

Procedure 1 is an annual relative accuracy test. However, PS-8A does not include a relative 

accuracy specification and instead correctly relies on calibration gas audits because there is no 

independent reference method. Furthermore, the cylinder gas audit levels for Procedure 1 may

not be appropriate for a revised PS-8A, especially if multi-range analyzers are necessary. 

Requirements at Appendix to Subpart EEE for hazardous waste combustors contain quality

assurance procedures for THC and other CEMS used at these facilities. These procedures should 

be modified for low-level measurements and appropriate requirements should be developed for 

Subpart LLL sources.

Response: The proposal identified PS-8A as the monitoring performance specification for THC 

monitoring through an oversight, and PS-8 is now specified. Also, the rule language now 

proscribes the THC CEMS span value as 40 ppm and the reference method for the RATA as 

Method 25A. With these revisions and in view of the THC standard concentration value, EPA is 

confident that the performance requirements of Procedure 1 of Appendix F are appropriate and 

can be met.

CEMS alternatives

Comment: One commenter (2844) stated that EPA should not require CEMS but instead look to 

other effective monitoring methods that are more practical and efficient. The commenter’s 

experience with a VOC Analyzer (CEMS) was that the unit requires a lot of maintenance, 

expense, and frequent repairs, resulting in increased downtime compared with priority pollutant 

CEMS.

Response: We believe that CEMS are the best alternative to demonstrate continuous compliance 

and that they are a demonstrated technology, as well as the source for all of the data used to 

develop the standard. However, we are always interested in the evolution of monitoring 

technologies and will consider source-specific alternatives proposed under the General 

Provisions.

Contradictory, erroneous requirements and clarifications

Comment: Several commenters (2845, 2859, and 2863) stated that numerous areas of the 

proposed regulations include contradictory, erroneous, or otherwise impractical requirements 

relating to compliance demonstrations in the performance testing requirements and or monitoring 

requirements. Comments are as follows:
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 The initial compliance demonstration procedures for total hydrocarbons appear 

contradictory and should be revised to be consistent with the proposed emission standards 

and 30-day rolling average for THC emissions. Specifically, §63.1350(h)(4) states that 

daily average THC concentration must not exceed the THC limit for new or reconstructed 

facilities which is inconsistent with §§63.1343, 63.1346, and 63.1350(h)(2) and (h)(3). 

The initial performance demonstration should be based on a properly calibrated and 

compliant CEMS and the initial performance test result must be based on the calculated 

average THC concentration for 30 kiln operating days. A definition for kiln operating day

must be established and must reflect a specified number of hours of kiln or raw material 

dryer operation at normal production conditions. Days with fewer operating hours than a 

kiln operating day should not be included in the 30 day average.

 The initial compliance demonstration procedures for total hydrocarbons specifies a 

performance test duration and conditions that are not appropriate. Section 

63.1349(b)(4)(i) addresses initial compliance for THC specifying a performance test 

duration of 24-hours, and calculating the daily average THC concentration from the 

hourly averages during the performance test. Furthermore, it states that initial compliance 

shall be demonstrated by conducting separate performance tests for in-line kiln/raw mills 

with the mill operating and with the raw mill off. This would require the facility to run in 

a mill-off condition for 24 hours, which is not possible. There should be no specification 

for separate initial compliance tests for mill-on and mill-off for in-line raw mills.

 The THC monitoring requirements for facilities complying with total organic HAP limits 

are inconsistent with the averaging period of the standard. Section 63.1350(r)(2) requires 

calculation of 3-hour average THC concentrations and stating that the 3-hour 

concentration may not exceed the average established during the initial performance test 

is not consistent with the basis of the limit. The site-specific THC emission limit is based 

on a 30-day rolling average and EPA should correct this apparent discrepancy.

 The testing to establish THC emission limits for facilities with in-line kiln/raw mills that 

choose to comply with total organic HAP limits should be simplified to require testing at 

the operating condition that is appropriate for the particular plant. Section 

63.1349(b)(4)(iii) requires performance tests to establish site-specific THC emissions 

limits corresponding to compliance with the emissions limits for total organic HAPs. For 

kiln/in-line raw mills, this section specifies that tests are to be conducted while the raw 

mill is off and while the raw mill is operating. This could potentially create different THC 

limits for the two operating conditions which becomes completely unworkable since 

compliance with the resulting standard is determined on a 30-day rolling average and will 

obviously contain both mill-on and mill-off operation. EPA should clarify that the test is 

to be inclusive of both mill on and mill off conditions and the full range of plant 

operations including feed materials and fuels/fuel combinations in order to develop a 

single alternate limit. EPA should not specify separate tests under mill-on and mill-off

conditions. Furthermore, where total speciated organic HAP emission tests demonstrate 

that emissions are below the emission limit, EPA should explicitly allow proportional 

extrapolation of the measured HAP and THC values to determine the corresponding THC

surrogate compliance limit.

 Section 63.1349(b)(4)(vi) states that emission tests to determine compliance with total 

inorganic HAP limits shall be repeated annually and this is inconsistent with other 
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sections of the proposed rule regarding the parameters to be tested and the frequency of 

the test, and this section should be changed. The word inorganic appears to be a 

typographical error and EPA should confirm that the phrase should be total organic HAP. 

There are no requirements for performance testing of inorganic HAP. The annual test 

requirement in this section also contradicts the proposal where it explicitly states that 

stack tests for organic HAP would be required every five years for kilns and raw material 

dryers meeting the organic HAP alterative to THC to determine the organic HAP 

component of their THC emissions. The proposal states that annual organic HAP tests are 

not necessary, will be very costly, and could be disruptive to plant operations. EPA 

should specify that testing should be conducted at least every five years. The facility 

should be permitted to conduct the testing more often than every five years and reset the 

alternative limit if changes in the facility materials or operations warrant such changes. In 

addition, because such testing for the organic HAP could result in THC levels higher than 

the previously determined alternate limit, the time period of the testing should not be 

included in the rolling average for compliance.

 EPA needs to add a formula to enable sources to weight the relative emissions 

contributions to determine compliance when emissions occur at two points. Many plants 

with indirect fired, in-line coal mills are designed to vent directly to atmosphere. 

Compliance with the organic HAP standard for a plant so configured should allow the 

combination of both stacks given that they both constitute sources of kiln gases. These 

commenters requested that EPA add to the rule a formula equivalent to Equation 2 of 

63.1349 whereby an affected source configured such as the one depicted below can 

demonstrate compliance with the THC standard by combining the concentrations from 

the main stack and the coal mill stack.

Response: We have made several clarifications and corrections in the final rule to respond to 

these comments, including:

1. Clarifying that the 30-day average is a rolling average,

2. Adding a definition of “kiln operating day,”

3. Raw mill off testing is required for the initial compliance test to establish the site-specific 

THC level. 

4. Removed paragraph 63.1350(r)(2), because this language is inconsistent with the 30-day

rolling average.

5. Replaced the reference to “inorganic” HAP emissions testing with “organic” HAP 

emissions testing.

6. Clarified that organic HAP testing is to occur at least every 30 months unless there are 

changes at the plant that warrant more frequent testing.

7. Clarified that data collected during a performance retest need not be incorporated into the 

existing 30-day rolling compliance average.
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As described elsewhere, we agree with comments that the initial performance test period 

should also be a 30-day average. Regarding the comment requesting proportional 

extrapolation of the measured HAP and THC values, we lack the data to establish such a 

provision. If a source needs to expand its operating range, it should retest and establish a new 

limit. Finally, the suggestion to add a formula to address combined concentrations from the 

main stack and coal stack is not needed, because of the concentration format of the standard.

Such a formula is only needed when the standard is in the form of a mass limit.

Comment: One commenter (2845) stated that the definition of total organic HAP in section 

63.1341 should be changed to add the reference to test methods EPA Method 18 and ASTM 

D6420, and adsorbent based methods or impinge train methods to test for total organic HAP for 

speciating organic HAP.

Response: The final rule includes a higher THC value than proposed, with the result that we do 

not think these additional methods are needed to determine total organic HAP. However, a 

source is always able to request an alternative method under the General Provisions.

Comment: One commenter (2845) provided the following suggestions and clarifications to 

§63.1349(b)(4)(i):

 Clarify that Alkali Bypass Stacks are exempted from CEM requirements for THC.

 A performance test for a source with a CEMS is duplicative and should not be required.

 The THC limit is a 30-day average (see §63.1350(h)(3)). Thus the requirement for the 

duration of a performance test to be 24 hours appears to be a typographical error.

 This section appears to require a 24-hour test while the raw mill is operating and a 24-

hour test while the raw mill is not operating. A typical downtime for a raw mill is 8 hours 

per day, one day per week. It is not possible for the majority of in-line kiln/raw mill 

systems to operate with the raw mill off for 24-hours.

 Raw Material Dryers also have THC limits, and thus may be required to use a continuous 

emission monitor and demonstrate compliance during raw mill on/off conditions based 

on the proposed rule. It should be clarified that the raw mill on/off condition is not 

needed for the performance test of the Raw Material Dryer as it is not directly associated 

with the kiln system.

 This requirement should be removed or updated, according to language provided.

Response: Alkali Bypass Stacks are subject to the standard. However, we have changed the 

final rule to allow the source to use the results of an initial performance and subsequent 

compliance test as a surrogate for continuous monitoring. We believe this is reasonable, given 

that the majority of emissions are coming from the main stack. We have clarified that the initial 

compliance test for the CEMS is the initial 30-day operating period. For the raw material dryer, 

testing is not required for the raw mill on/off conditions.

Comment: One commenter (2845) suggested that §63.1350(h)(2) and (3) be combined into one 

requirement.
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Response: We believe it is clearer to distinguish existing source requirements from new and 

reconstructed sources in the format of the standards.

Comment: One commenter (2845) suggested that the combustion system inspection and 

reporting required under §63.1350(i), §63.1350(a)(3), and §63.1354(b)(9)(iv)are no longer 

needed and can be removed. The combustion system inspection was previously included in lieu 

of a THC limit. Now that there is a THC limit, these inspection, recordkeeping and reporting 

requirements are no longer needed.

Response: These requirements were actually part of the 1999 final rule and were intended to 

help ensure compliance with the dioxin/furan emissions limit. Because the dioxin/furan emission 

limit has not changed, these requirements are still applicable.

Comment: One commenter (2845) included the suggestion that the EPA should clarify that THC 

is on a propane basis and is a 30-day rolling average at 7 percent oxygen. 

Response: We agree and the final rule contains this clarification.

2.6.5 Impacts

Performance of controls overstated, impacts understated

Comment: Several comments (2841, 2844, 2845, 2864, and 2889) were received that question 

EPA’s impact analysis for THC including the performance of ACI and RTO, and adverse 

impacts associated with the use of RTO.

Commenter 2845 stated that EPA has overestimated the use of ACI and underestimated the use 

of RTO. According to the commenter, the EPA based the ACI information on one single kiln that 

is no longer in service with emissions and a configuration that was unusual for the industry. EPA 

stated that 75 percent control should be achieved for cement kilns using ACI because it was 

achieved for dioxin/furans in the incinerator industry. The commenter disagreed with the 

comparison for the following reasons:

 There are substantial differences between cement kilns and incinerators in operations, 

plant configurations, and flue gas composition as well being two different industries, 

which can affect the effectiveness of ACI for THC.

 THC cannot be compared with dioxins/furans because THC also consists of low carbonbased VOC (such as methane, ethane, and formaldehyde), which has a substantial impact 

on the effectiveness of ACI. 

 Formaldehyde is not expected to be well controlled using ACI.

 The ability of ACI to capture THC is total a physisorption-based mechanism and 

therefore the effectiveness of ACI would be also entirely mass-transfer-limited.

 Lower THC concentrations would have to have an increase in the ACI feed rate to match 

the sample percentage removed of THC at higher concentrations.
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 The percentage of low-carbon THC is highly variable and the available data indicates that 

low-carbon species can be <5 to >90 percent of THC, which will impact the effectiveness 

of ACI.

 Using ACI would have an adverse impact on the ability to reuse cement kiln dust. 

Recycling the CKD would result in revolatilization of some of the THC. Insufflation of a 

portion of CKD is possible for some kilns, which would destroy the captured THC. It 

may be necessary to add a polishing baghouse thereby increasing costs 10 to 15 times 

that of using ACI alone.

 Dioxins/Furans may be increased when using ACI to control THC for cement plants that 

burn hazardous waste. 

Several commenters (2844 and 2845) noted that EPA has proposed using ACI to provide 

simultaneous control for both mercury and THC. Although a standard powdered activated carbon 

may control both mercury and THC (greater than 90 percent removal), there is no data to support 

the removal of THC when a halogenated carbon was used to control high elemental mercury

concentrations. 

Commenters 2864 and 2889 expressed concerns about operating problems caused by a HCl wet 

scrubber ahead of a RTO. Commenter 2864 provided an example of their experience with RTO 

with wet scrubbers at two wet kilns. Although 89 percent THC removal was reported initially, 

the system was plagued with problems and equipment failure. After six years of repairs and 

upgrades, the system worked in the 2008 ozone season and the plant was shut down permanently 

later that year. Commenter 2889 stated that EPA has not considered the costs due to kiln outages 

caused by the unreliability of wet scrubbers and RTO required by the proposed amendments. 

Both wet scrubbers and RTO in the cement industry and other industries have been subject to 

frequent maintenance problems. Existing kilns installing wet scrubbers in series with a RTO will 

compound the reliability issue. Problems affecting either one of the control systems will require 

the kiln to shut down. The cost for the lost production should be included in these cost impact 

analyses.

Commenters 2844 and 2889 stated that EPA’s claimed activated carbon injection system THC 

control efficiency of 75 to 80 percent is not adequately supported and does not take into account 

the low control efficiency for light hydrocarbons. As a consequence of the unrealistically highly 

assumed ACI removal efficiency for THC, EPA has underestimated the number of RTO that will 

be needed to achieve the standard for existing kilns. The cost, environmental, energy, and 

economic impacts of the proposed amendments described in Section VI of the Preamble are 

inaccurate due to the probable need for numerous RTO. 

Commenter 2844 stated that RTO are not expected to provide for continuous compliance with 

the limit. Vendors have not been willing to guarantee levels below the proposed standards of 6 

and 7 ppm. The one commercial application of an RTO on a kiln cannot meet the standard, and a 

number of units have such high THCs that RTO may not be able to lower the emissions 

sufficiently to get close to the proposed limit. Where the concentrations of THC in kiln stacks is 

low, but still over the standard, the emissions reductions that an RTO can provide are small.
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Commenters 2841, 2844, 2845, and 2889 stated that the requirement of regenerative thermal 

oxidizers (RTO’s) for control of THC will result in an increase of CO2 emissions, along with a 

host of other emission impacts due to increased fuel and energy consumption. 

 One commenter (2845) stated the following regarding the use of RTO’s for THC control:

 RTO will increase cost, energy use, and greenhouse gas emissions. 

 RTO have performance limitations. Based on available data, RTO have a performance 

limit of 10 ppm THC which restricts the emission control capabilities. Therefore, the 

THC emission standards should be no less than 10 ppm.

 RTO are not cost-effective due to high maintenance costs (especially in harsh weather). 

Maintenance includes component replacements and periodic cleaning and washing.

 Numerous cement plants lack access or have limited access to the natural gas need to 

operate RTO.

RTO use will increase green house gas emissions with higher NOx emissions due to the use of 

natural gas or propane used for firing. The commenter included data concerning the increase 

greenhouse gas emissions with their comment.

Commenter 2900 provided stack test data for THC emissions. The data demonstrates that the 

plant may have three or more times the new EPA limit in emissions and may be unable to meet 

compliance. 

Response: Hazardous waste burning cement kilns are not subject to the subpart LLL standards.

The proposed level of control for THC is exceeded in practice by the only cement plant in the 

U.S. equipped with an ACI system. With regards to the comment regarding dioxins/furans 

emissions potentially increasing as a result of these rule requirements, hazardous waste burning 

cement kilns are not subject to subpart LLL standards. For those comments related to control 

device performance and the secondary impacts of increased CO2 and GHG emissions from 

oxidizers, those impacts were considered in our analysis and were based on the best information 

available to us. If a given facility wants to avoid such secondary impacts, the organic HAP limit 

is a viable compliance option for them.

Comment: One commenter (2928) stated that RTO are technically feasible and cost effective 

options that can be used to meet the proposed standards. TXI operates the largest cement kiln in 

the state of Texas in Midlothian with an RTO acting as an effective afterburner for VOC, THC 

and CO emissions. It is 80-90 percent effective in removing these contaminants from the plume. 

As has already been noted, SCR technology also significantly reduces VOCs/THCs from the 

exhaust.

Response: EPA does not anticipate that widespread use of RTOs will be needed to comply with 

the THC standard. See Regulatory Impact Analysis: Amendments to the NESHAP and NSPS for 

the Portland Cement Manufacturing Industry, Final Report, August 2010.
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Baseline THC emissions

Comment: One commenter (2845) stated that when evaluating the emissions database for each 

kiln EPA used, the standardized format is problematic from multiple standpoints. Here are 

several related examples:

 In reviewing data for those facilities for which EPA had actual data, there appears to be 

the following types of issues:

– Projected emission rates were extrapolated from a particular time period of 

production (2002 production extrapolated to 2005) that does not necessarily reflect 

the actual emissions for a particular kiln

– Kiln emission allocations for facilities with multiple kilns are not consistent, with the 

following examples:

• Main stack emission rates where 3 kilns feed a common stack are applied to each 

of the three kilns individually for some pollutants; thereby overestimating 

individual kiln emissions.

• Emission rates are apportioned improperly between the multiple kilns.

 Deriving factors to extrapolate HAP emissions from those facilities where EPA has data 

to the remainder of the kilns, does not have a sound justification as a basis for such 

detailed cost calculations. For the THC factor, removing facilities with high levels of 

THC is not warranted. With many facilities not having THC data, and THC emissions 

being based on geographic location, other cases of higher THC emissions is a realistic 

outcome. EPA’s factor of 21 ppm was compared to the average of industry’s 

corresponding database. Removing only the highest THC emission kiln (which is now 

closed), the average THC emission rate was calculated to be 28.1 ppm.

 The use of dry versus actual flow rates appears to be used inconsistently.

 The assumption that most plants burn coal is not accurate and will affect flow rates, and 

therefore emissions.

 The data includes some HWC (waste burning kilns) and kilns currently shut down. The 

inclusion of this type of data skews the database.

 Factors established by kiln type may not be as relevant as factoring by geographic area, 

as the newly regulated HAPs generally are variable due to the limestone and/or silica 

source quarried on-site.

Response: The database for this rulemaking has been updated to account for the kilns active in 

2009 that are subject to this rule. Hazardous waste kilns are included in the database for the ISIS

Cement Model but are not subject to this rule. THC emissions for each kiln subject to this rule 

were calculated using emission factors developed from the data EPA received thru the 

Information Collection Request (ICR). For kilns where we did not have specific emissions 

information, we developed an average emissions factor. We removed the highest emitting kiln 

because we believe it represents an outlier. We know of no other facility that has emission even 

close to the highest THC emitting kiln. We recognize that using an average emissions factor may
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overestimate or underestimate costs. However, we know of no more accurate way to estimates 

emissions and costs. 

2.6.6 Other

THC emissions due to burning waste vs due to limestone

Comment: One commenter (2928) supported the proposed emission standard for THC. The 

commenter noted that cement industry will argue that the entireties of their THC and CO 

emissions are from the cooking of the limestone that contains these chemicals naturally. EPA 

should be skeptical of this claim without proof when so many cement plants are burning wastes, 

including tires, asphalt shingles and oil filter fluff that contribute directly to these kinds of 

emissions. Industry must distinguish between those THC emissions legitimately caused by raw 

materials and those cause by the burning of waste fuels.

Response: EPA acknowledges the commenter’s support and notes that the expansion of the 

database for THC more accurately reflects performance than the more limited information at 

proposal.

2.7 HCl Standards

Comment: One commenter (2898) recommended that EPA adopt the proposed MACT floor for 

HCl. 

Response: EPA acknowledges the support of this commenter, although the proposed standard 

did not properly account for variability in the analytic detection method due to its quantitation 

limit.

2.7.1 Legal Issues

Health based vs MACT emission standards

Comment: Many commenters expressed their preference for EPA’s previous health-based 

approach to setting limits for HCl.

Commenter 2830 requested that EPA clearly articulate why it did not reaffirm its position in the 

original proposed NESHAP where it found that an HCl standard is not necessary given the low 

HCl emissions from cement kilns and risk assessment findings from a national survey of the 

industry showing a lack of risk to health or the environment from any cement facility. There is 

no compelling environmental or public health reason for EPA to change course at this time, and 

relying on §112(d)(4) would be consistent with Congressional intent to not impose burdensome 

HAPs regulations where no risk to public health or the environment exists.

Commenters 2841, 2844, 2859, and 2890 stated that in previous MACT rulemakings, the 

Agency determined that HCl’s nature as a threshold pollutant and the clearly demonstrated lack 

of risk posed by HCl emissions at the property boundaries of cement manufacturing facilities 

precluded the need to set such a standard. EPA’s reversal of this approach in this latest proposed 

rulemaking runs completely counter to its approach in other rulemakings.
132

Commenters 2844, 2845, 2859, 2864, 2874, 2901, 2915, and 2916 stated that to the extent that 

EPA believes it needs to address HCl in this rulemaking, the standard should continue to be 

health-based. 

Commenter 2845 proposes that sources be allowed to set a site-specific limit, ensuring that a 

national standard of a hazard index of 1.0 is not exceeded, thereby demonstrating an ample 

margin of safety. This approach was adopted in EPA’s hazardous waste combustor MACT rule 

and the industrial boiler MACT rule (for HCl). There is no compelling environmental or public 

health reason for EPA to change course at this time, and relying on §112(d)(4) would be 

consistent with Congressional intent to not impose burdensome HAPs regulations where no risk 

to public health or the environment exists. 

Commenters 2845, 2874, and 2901 stated that EPA should reaffirm the position it took in the 

December 2006 Portland Cement NESHAP rule that in accordance with §112(d)(4) that it is not 

necessary to set a MACT standard for HCl. In two MACT rulemakings for other industry

sectors, EPA has decided that an HCl standard was not warranted where EPA determined that 

even the individuals with the greatest exposure to HCl emissions from neighboring facilities 

would be safe with an ample margin of safety. EPA now proposes to reverse course because 

controls installed to reduce HCl emissions would supposedly result in emissions reductions of 

sulfur dioxide and other non-HAP pollutants. MACT standards, however, may only address 

HAPs. The commenter states that it is inconsistent with CAA §112(d) and arbitrary for EPA to 

depart from precedents in the 2006 and other earlier MACT rulemakings to set an HCl standard 

for the purpose of reducing criteria and other non-HAP pollutants.

If EPA does decide to set a standard, commenters 2845, 2874, and 2901 stated that EPA should 

follow the approach it adopted in its hazardous waste combustor MACT rule (for total chlorine) 

and the industrial boiler MACT rule (for HCl), where EPA established health-based compliance 

alternatives. In those rulemakings, EPA set a national standard such that for someone living at 

the fence line of the facility, the hazard index could not exceed 1.0 (thus providing an ample 

margin of safety). The facility then would be able to set a site-specific limit, ensuring that the 

hazard index did not exceed 1.0.

Commenters 2845, 2874, and 2901 noted that EPA’s 23 ppm by volume (ppmv) suggested notto-exceed limit is an order of magnitude less stringent than the proposed 2.0 ppmv existing 

source standard for HCl. Thus, if EPA adopts the standard in the Proposal, it will be setting a 

standard that is an order of magnitude more stringent than the level (using extremely

conservative assumptions) necessary to protect human health. Commenters 2844 and 2901 

suggested that if EPA decides that an HCl limit is needed, the Agency should set a limit based on 

protection of health at 23 ppmv. 

Commenter 2901 stated that although some might argue that HCl is not a threshold pollutant 

because it has not been shown to be non-carcinogenic, Congress stated that ammonia was a HAP 

with a well-established threshold for which EPA could set a risk-based standard. A comparison 

of the Integrated Risk Information System (IRIS) information relating to carcinogenicity for 

ammonia and HCl shows that the two chemicals have the same notation relating to 

carcinogenicity, not undergone a complete evaluation and determination under U.S. EPA’s IRIS 

program for evidence of human carcinogenic potential. 
133

Commenters 2845 and 2846 stated that the proposal solicits comment on whether EPA should 

promulgate a health-based standard for HCl under §112(d)(4) that would be in the form of a notto-exceed standard, based on risk analysis of 68 facilities using a screening level dispersion 

model (AERSCREEN). EPA states that such a not-to-exceed standard would be set at a level of 

23 ppmv. 

 Commenter 2845 disagreed that EPA must issue a standard.

 Commenter 2846 agreed that a health-based approach will allow facilities alternative 

compliance options so that capital and operating costs are not incurred solely on controls 

for control’s sake, for example, where there is no HCl health risk and where investing in 

a control technology brings minimal or no co-benefit.

Commenter 2901 stated that EPA’s analysis for this proposed rule shows that 23 ppmv emitted 

from any plant would result in an annual average ground concentration of more than 20 μg/m3.

Because the RfC for HCl is 20 μg/m3an emission standard of 23 ppmv would be protective for 

any facility. The commenter stated that a 2 ppmv technology-based standard is unnecessary

when EPA has already concluded that 23 ppmv is protective with an ample margin of safety, and 

why Congress gave EPA the flexibility to use a risk-based alternative. As Congress noted in the 

legislative history, §112(d)(4) was enacted to avoid expenditures by regulated entities which do 

not have public health or environmental benefit.

Response: Most of these issues are responded to in the preamble in section IV.A.1.d.iv. Given 

the enormous environmental benefits projected from a MACT standard for HCl, EPA rejects the 

characterization that a MACT standard would be ‘control for control’s sake’.

Comment: Several commenters (2816, 2898 and 2911) agreed with EPA’s decision to not 

propose a health-based standard. The commenters agreed that a health-based standard should not 

replace a MACT standard for HCl. The CAA allows the EPA to consider the health threshold for 

a HAP in setting emission standards, if one has been established. 42 U.S.C. §7412(d)(4). The 

commenter noted that the use of the term has been is retrospective, and shows that Congress 

intended that EPA may only use the authority when an accepted threshold is already in existence. 

Further, Congress specified the kind of proof that EPA needed in order to invoke subsection 

112(d)(4): direct evidence of no effects. The Senate report on the 1990 CAA stated that the 

provision allows EPA to use the no observable effects level (NOEL). Thus, unless there is clear 

evidence of an existing threshold for the pollutants in question, EPA may not rely on subsection 

112(d)(4) at all. The Agency may not speculate from inconclusive science; rather, it must be sure 

that there are no effects from exposure at the level chosen for the emission standard.

Commenter 2898 stated that the 2006 rule that EPA relies on for a possible alternative healthbased standard has been challenged in court and is being held in abeyance pending the results of 

EPA’s reconsideration of the rule, carried out in the present rulemaking (74 FR 21139-40, 

21154). Thus, the 2006 rule cannot be said to have established a health threshold. 

According to commenter 2911, HCl is not the only acid gas that cement plants emit. Among the 

other acid gases that cement plants emit are at least two listed hazardous air pollutants, hydrogen 

fluoride and hydrogen cyanide. EPA has a clear statutory duty to set emission standards for each 

HAP that a source emits and, even if EPA could set §112(d)(4) standards for HCl, the agency 
134

does not and cannot claim that there is an established threshold either for hydrogen fluoride or 

for hydrogen cyanide. Further, because EPA must set standards for the latter pollutants under 

§112(d)(2) and (3), a §112(d)(4) standard for HCl could not possibly serve as a surrogate for 

either of them. To satisfy the CAA, EPA must set individual standards for both hydrogen 

fluoride and hydrogen cyanide or must use a valid surrogate standard for them.

Response: EPA thanks the commenters for their support on our decision to not set health based 

standard for HCl. Regarding the suggestion that EPA set limits for HG and HCN, EPA notes that 

a factor in not setting a health-based standard was that setting a MACT standard for HCl not only

controlled HCl but also co-controlled other HAP (such as HF, Chlorine (Cl2), and hydrogen 

cyanide (HCN)) and criteria pollutants yielding very substantial environmental benefits. EPA 

agrees that HF and HCN emissions from cement manufacturing should be reduced when possible 

and believes that the final rule helps to accomplish that end.

Claiming benefits from SO2 reduction not permissible

Comment: Several commenters (2841, 2844, 2846, and 2916) stated that MACT standards may

only address HAP pollutants, but EPA is trying to control sulfur dioxide and other non-HAP 

pollutants through application of control technology used to reduce HCl.

Commenter 2846 stated that basing MACT limits on such considerations is not permissible and 

limiting compliance flexibility by excluding other options is not good policy. Section 112(d)(2) 

provides an express list of factors that EPA may consider in setting MACT standards – including 

the cost of achieving such emission reduction, and any non-air quality health and environmental 

impacts and energy requirements. This list does not allow consideration of non-HAP air quality 

benefits, such as the co-benefits of reducing PM2.5 emissions.

One commenter (2898) stated that Congress intended EPA to consider benefits such as a 

reduction in emissions of SO2 and other acid gases, along with condensable PM, ammonia, and 

semivolatile compounds when setting a MACT floor, and EPA has appropriately considered 

these co-benefits in deciding not to set health-based standards for HCl. 

Response: Although MACT standards may directly regulate only HAPs and not criteria 

pollutants, Congress did recognize, in the legislative history to section 112(d)(4), that MACT 

standards would have the collateral benefit of controlling criteria pollutants as well and viewed 

this as an important benefit of the air toxics program.. See S. Rep. No. 101-228, 101st Cong. 1st

sess. at 172. EPA consequently does not accept the argument that it cannot consider reductions 

of criteria pollutants, for example in determining whether to take or not take certain discretionary

actions, such as whether to adopt a risk-based standard under section 112 (d)(4) or to adopt 

standards for HAP metals that truly reflect MACT by amending the PM standard. There appears 

to be no valid reason that, where EPA has discretion in what type of standard to adopt, EPA must 

ignore controls which further the health and environmental outcomes at which section 112 (d) of 

the Act is fundamentally aimed because such controls not only reduce HAP emissions but 

emissions of other air pollutants as well.2 Thus, commenter 2844’s invocation of the decision 

factors enumerated in section 112 (d)(2) seems off point, since the issue being addressed is not 

 

2 EPA notes the support of commenter 2898 in this regard.
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whether to regulate non-HAP (EPA is not), whether to consider other air quality benefits in 

setting section 112 (d)(2) standards (EPA is not), but rather whether to make the discretionary

choice to regulate certain HAP based on the MACT approach and whether EPA must put 

blinders on and ignore collateral environmental benefits when choosing whether or not to 

exercise that discretion. EPA knows of no principle in law or common sense that precludes it 

from doing so. 

With regard to the comments specifically addressing SO2, EPA is regulating SO2 emissions for 

new sources and modified sources under the NSPS rulemaking. EPA is not regulating SO2 in the 

NESHAP, although EPA recognizes that any other SO2 emission reduction obtained from 

existing sources is a co-benefit resulting from the control technology selected to comply with 

either the mercury and/or HCl NESHAP limits. EPA recognizes the multi pollutant interactions 

and co-benefits of this rulemaking and how a well planned integrated control strategy can 

maximize the environmental results while optimizing the cost invested by a facility to comply 

with such regulation. 

SO2 as surrogate

Comment: Several commenters (2898 and 2911) agreed with EPA’s decision not to propose 

using SO2 as a surrogate for HCl. HCl is not present in SO2, and control of SO2 is not the only 

means by which cement kilns achieve reductions in HCl. To the contrary some kilns achieve HCl 

reductions through the use of raw materials and fuels that contain less chlorine.

Response: We agree with the comments and are not using SO2 as a surrogate for HCl.

2.7.2 Adequacy of Floor Determinations (Existing and New)

Adequacy of data

Comment: One commenter (2144) agreed with EPA’s HCl emission limit of 2 ppmvd for 

existing sources or a more stringent standard if the statistical methodology biased the results on 

the high side. The commenter agrees with the 0.1 ppmvd for new kilns unless the statistical 

methodology justifies and the law allows a greater limit not to exceed 2 ppmvd. The commenter 

has not yet determined whether it agrees with the method by which existing and new kiln 

emission standards were set.

Commenter 2898 agreed with the EPA proposal to base the MACT floor for HCl for existing 

sources at the average of the lowest emitting 12 percent of the kilns for which it has data and at 

the emission rate of the single lowest emitting source for new sources is consistent with the 

CAA’s requirements.

Response: The final standards for HCl are 3 ppmvd on a dry basis at 7 percent oxygen, for both 

new and existing sources. A detailed discussion of the MACT floor determination for HCl is 

included in the preamble (section IV.A.1.e).

Comment: Many commenters stated that EPA’s MACT floor analysis for HCl was inadequate 

or that EPA lacked adequate data.
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Several commenters (2830, 2836, 2845, and 2859) stated that EPA should reaffirm its position in 

the 2006 NESHAP where it found that a HCl standard is not necessary given the low HCl 

emissions from cement kilns and risk assessment findings from a national survey of the industry

showing a lack of risk to health or the environment from any cement facility. The commenters 

further stated that EPA’s HCl emissions data is not sufficient to establish a defensible MACT 

standard. The majority of emissions data used by EPA is from area sources of HAPs and/or 

suffers from data quality issues, such as data recorded below the quantification limits of the test 

method or by using improper test methods. After reviewing the data, the commenters believe 

EPA has emission data from only one source that would be a defensible data point. EPA should 

not base a nationwide existing NESHAP standard on data from one facility. Clearly, no 

variability considerations are afforded as a result of using one data point. 

Commenter 2841 stated that EPA gave limited notice to the industry to respond and provide 

additional data, is inappropriate when considering the development of any standard.

Commenters 2845, 2846, 2863, and 2889 stated that EPA should not use HCl emission data 

below the current Method 321 practical quantification limit. The commenters stated that it is 

unnecessary to set a floor or standard for HCl, but if EPA decides to do so it should exclude all 

test data below the practical quantification limit and exclude from the pool of MACT floor 

sources any kiln with test data below that limit. Given that the data were gathered when Method 

321 identified a practical quantification limit in the range from 1000 to 5000 parts per billion for 

specific path length and test conditions, EPA should not use any data below that range. If EPA 

believes it may be appropriate to revise Method 321, it should conduct a formal review process 

for the Method, and make available to the public any relevant supporting information. But if 

EPA does amend Method 321, it should not apply the changes retroactively.

Commenters 2836, 2844, 2845, 2859, 2863, and 2889 stated that the existing source floor is 

improperly based on inadequate data. Commenters 2845 and 2863 stated that there are not 

enough data upon which to establish an existing source MACT floor. One-third of the sources in 

EPA’s database – 9 of the 27 sources listed in Table 5 of the preamble – are true area sources. 

Commenters noted that test data for so many of the 27 kilns are invalid that when true area 

sources and sources with invalid data are excluded, only one kiln remains (i.e., only Kiln 20 in 

the table is a major source for which there are valid HCl test data). Additional concerns 

presented by the commenters were:

 EPA established the proposed HCl MACT floor for existing sources based upon Method 

321 test data from what it describes as the top 12 percent of kilns for which it had such 

data. There were only 8 of 27 kilns in EPA Table 5 of the preamble with Method 321 

data and EPA examined the top four kilns without respect to test method. The lowest 

emitters, Kilns 1 and 2 used data from California Air Resources Board (CARB) 421, 

which is specifically disallowed. 

 Only one of the kiln sets from which EPA calculated the floor is a major source. EPA 

must change the kilns from which it sets that existing source floor. The proposal notes 

that it is appropriate to limit the floor database to major sources. This is correct because 

area sources are not in the same category or subcategory as the major sources for which 

EPA is setting the floor and issuing standards. CAA §112(d)(3).
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 EPA should use data from 5 kilns, rather than 4, to establish the floor. Where there are 30 

or more sources in a category, but fewer than 30 with data, CAA §112(d)(3) should be 

read to require the use of 5 sources to establish the floor.

 Much of the HCl data are based on invalid tests. EPA must exclude results from HCl 

testing conducted with methods other than Method 321 or ASTM D6348. Some methods 

were incorrectly applied. The commenter provided an appendix with tables detailing the 

commenter’s concerns about test data. The commenter recommended that EPA exclude 

19 kilns from its database due to invalid tests.

Response: In response to comments we received on the HCl MACT floor analysis, EPA revised 

its analysis. We have removed those natural area sources from the floor analysis and because 

many of the source tests were not actually EPA Method 321 tests and others lacked important 

quality assurance information, we used our authority under section 114 to collect additional data.

We used this new data set to calculate a MACT floor. See the preamble to the final rule for a 

discussion of the revised analysis.

Comment: Several commenters (2830, 2844, and 2845) stated that EPA has provided no support 

for its assumption that the stack testing data used to establish the HCl MACT floors can be 

correlated to continuous emissions monitoring data to demonstrate compliance. The commenter 

states that EPA has provided no analysis to demonstrate that the variability of data provided by 

the proposed emission monitoring methods would be equivalent to the variability of the stack 

tests. Under the Proposal, the HCl MACT floor was set based on the averaging of stack test data. 

However, compliance emission measurements will need to be made based on continuous 

measurements. The D.C. Circuit disfavors standards that impose a method for demonstrating 

compliance that differs significantly from the method used to arrive at the standard. This is 

precisely the case here.

Response: As stated in the preamble to the final rule, EPA has significantly increased the level 

of the standard to account for any uncertainty associated with the analytic method detection 

level, and is also expressing the standard as a 30-day limit. Since the level of the standard is 

higher than the stack measurements, and is averaged over 30 days (which normally would result 

in a lower level due to the multiple observations which dampen variability), EPA does not 

believe there is any legitimate issue that use of a CEM to measure the standard makes the 

standard more stringent than the underlying data would support. At the same time, EPA believes 

that its approach is a legitimate way to gauge best performers’ performance given the uncertainty

associated with the analytic method detection limit..

Subcategorization

Comment: One commenter (2863) suggested that EPA should subcategorize to reflect arid 

sources. EPA cannot reasonably set a standard based on a control technology type that cannot be 

employed in a large portion of the western United States. EPA considered wet scrubbers as a 

basis for meeting the HCl standard and no consideration was given for alternative types of 

control. However, wet scrubbers are not a viable control technology in vast parts of the western 

United States where water is not available for use in a scrubber. The commenter stated that given 

the unavailability of water, EPA should create a subcategory for arid areas for those plants that 
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cannot use wet scrubbers. Failure to do so would break from well established precedent and 

arbitrarily impact plants in one part of the country.

Response: As noted in the preamble, we are not mandating wet scrubber control technology in 

this rule. Other control techniques are available (hydrated finely ground lime, spray dryers, fuel 

and additive switching) that we believe would allow a cement kiln to meet the HCl emission 

limits in areas where sufficient water for a wet scrubber is not available. Although we have no 

cost data available for these alternative control techniques (some of which would be sitespecific), we anticipate that these control techniques would be no more expensive that a wet 

scrubber.

CISWI

Comment: One commenter (2889) stated that the MACT floor for HCl should be re-evaluated 

after the data anticipated in response to the EPA §114 Letter CISWI request, to be submitted by

October 2009 is evaluated. 

Response: EPA performed a separate date gathering for HCl emission data as part of this 

rulemaking and used these data to recalculate the MACT floor.

2.7.4 Compliance Assurance

Support proposed monitoring method

Comment: One commenter (2144) stated that EPA should require HCl-CEMS for compliance.

Response: EPA acknowledges the commenter’s support

Comment: Commenter 2832 supports EPA’s proposal to reject EPA Reference Method 26/26A 

stack testing data. Method 26/26A does not accurately measure HCl.

Response: EPA acknowledges the commenter’s support

Compliance Based on Performance Testing

Commenter 2845 stated that EPA should require that compliance with HCl limits should be 

measured by periodic stack tests. Because the HCl floors were developed from HCl stack test 

data, the standard for HCl should be based on periodic stack testing. EPA must evaluate valid 

data from Method 321/ASTM D6348 stack tests instead of the data contained in Table 5 of the 

proposal. Using CEMS to measure compliance effectively makes the standard more stringent 

than what has been achieved by the best-performing sources. If CEMS compliance 

demonstration is retained, then the limit for CEMS compliance must be raised to reflect the 

added variability that will be measured by the CEMS. While continuous measurement will 

capture variability of emissions 24 hours per day, 7 days per week over the full range of process 

and control system operating conditions over the life of the plant and its associated quarry, the 

stack test is merely a snapshot in time. By definition, a stack test contains no parameter related to 

variability other than that obtained during the three hours of testing. In addition to the inherent 

variability of HCl emissions, a CEMS standard must also consider the inaccuracy of the CEMS 
139

as determined (and allowed) relative to the required stack test methods, the uncertainty of 

calibration standards/materials, and other factors affecting the sampling, transport, and analysis 

of HCl which is a highly reactive compound.

Response: See response in preamble, as well as the response above to commenter 2844.

Monitoring requirements for scrubbers

Comment: One commenter (2911) disagreed with EPA’s proposed requirement to test sources 

with limestone scrubbers no more than every five years. The commenter stated that monitoring 

must be sufficient to assure continuous compliance with emission standards and to enable 

sources to certify accurately whether their compliance with emission standards is continuous or 

intermittent and to report any deviation from those standards. Because both chlorine inputs and 

the performance of the scrubber may change significantly over five years, testing just once every

five years cannot possibly provide the required assurance.

Response: Given the efficiency of wet scrubbers in removing HCl, we believe that parameter 

monitoring is generally sufficient to demonstrate compliance combined with periodic testing.

However, we agree that a 5 year period between tests may be too long for the reason noted by the 

commenter and have changed the testing frequency to 30 months. .

Issues with use of CEMS for HCl compliance monitoring

Comment: Many commenters cited difficulties in the use of CEMS to determine compliance 

with the HCl emission limits.

Commenters 2622 and 2889 stated that there will be difficulties conducting a RATA on HCl 

CEMS operating at HCl concentrations below 2 ppmvd. Commenter 2622 stated that because 

that proposal calls for RATA on HCl monitors when the emission limits are low, EPA will need 

to set a low emissions criteria for passing a RATA. The commenter expressed concern that 

20 percent of the reference method or 10 percent of the emission limit will be too restrictive.

Commenter 2844 stated that that given the level of the standard, a CEMS will require FTIR and 

the commenter is not aware of such CEMS available for purchase. The commenter recommends 

that compliance be based on periodic stack tests.

Commenters 2844 and 2846 stated that the new source HCl limit is below the published 

Method 321 detection limit and it is not appropriate to adopt a limit that is inconsistent with the 

existing standardized test method.

Commenters 2845, 2846, 2858, and 2859 stated that HCl CEMS cannot be used to demonstrate 

compliance at the levels proposed by EPA in this rule. Although HCl CEMS are installed in 

some hazardous waste incinerators, the concentrations being monitored at the incinerators are 

much higher than the HCl detection limit based concentration standard proposed by EPA for 

cement plants. In addition, calibration gases are not commercially available at the concentration 

levels proposed by EPA in this rule. Commenter 2845 expects a very high learning curve 

associated with operating and maintaining these technically challenging devices. This industry 

has little experience with their use and, since HCl CEMS are not widely used in other industries, 
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very little outside assistance can be provided through industry workgroups. As with mercury 

CEMS, EPA should resolve the reliability and performance issues with HCl CEMS before 

imposing substantial risks and costs on the portland cement industry. Although SO2 control is not 

the primary purpose of installing a wet scrubber under the proposed rule, the scrubber would be 

designed as if SO2 removal were the purpose. 

Commenter 2855 stated that FTIR based HCl CEMS cannot function at cement plants at the 

concentration levels proposed in the Rule. HCl CEMS are installed at some hazardous waste 

incinerators, but generally are process instruments relied on to provide measurements of HCl 

levels from the incineration process and are not FTIR based. The use of an FTIR-based CEMS 

for monitoring compliance at a cement plant at such low levels of HCl introduces a number of 

problems and concerns for the cement industry:

 Calibration gases are not commercially available at the concentration levels proposed by 

EPA in this rule. The lowest concentrations of HCl calibration gases commercially

available are between 5 and 10 ppm, with an accuracy of ±10% (0.5 ppm to 1 ppm). 

These calibration gases are 25 to 5 times greater than the proposed HCl standard for 

existing plants.

 There is no independent anchor for HCl calibration gas certification and the lowest 

concentration range available is over twice the proposed standard with a +/- 10% 

accuracy, numerous uncertainties are introduced to any data that are collected for the 

purposes of demonstrating compliance.

 The industry expects a very high learning curve associated with operating and 

maintaining these devices. The industry has little experience with their use and 

manufacturers have not sold many monitoring systems into the cement industry. 

Commenter 2855 stated that the current state of the technology for FTIR CEMS for HCl is such 

that providing precise accurate measurements below 2 ppm HCl will be a challenge and has not 

routinely been demonstrated in full-scale industrial applications.

Commenter 2855 stated that a moratorium of 18 months is needed for any HCl monitoring

requirements that may prevail for new and refurbished kilns having to meet the requirements of 

the standard on startup or promulgation.

Response: Several comments relate to the low level of the proposed HCl standards. We believe 

that these comments have merit and explain in the preamble that we are adopting a standard of 

3 ppmv to accommodate issues relating to uncertainties of reliably measuring below that value.

We have also modified the RATA emissions criteria to allow measurements up to 20 percent of 

the limit, as we have done in other relatively low emissions concentrations situations.

Regarding concerns about the use of FTIR, a number of vendors sell FTIR instruments, and they

will work with their customers to adapt the instruments to the needs of particular facilities. In

addition, calibration gases are readily available at 5 ppm and even down to 2.9 ppm. Method 205 

may be used for further gas dilution (yielding high quality standards) down to the levels needed.

We have also talked to vendors who state they can measure HCl down to 2 ppm. (Email from 

Jeffrey Lacoss to Rima Howell RE: Quick Question: PS-15. March 5, 2010. As forwarded to 

Robin Segall on March 5, 2010. Document in Docket).
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Commenters also raise concerns about the learning curve associated with HCl CEMS. We note 

that sources have 3 years to comply with the standard, which will be sufficient time to implement 

a working CEMS.

Comment: One commenter (2855) provided comments related to detection limit issues:

 EPA erred when they focused on detection limits in setting the proposed standard and 

mandated use of an FTIR based CEMS.

 Accuracy is unknown at the detection level; therefore accuracy at the proposed 

compliance level cannot be demonstrated.

 EPA focused on the detection limits associated with Method 321 area source tests 

contained in the docket for HCl in establishing the proposed HCl standard. EPA must not 

establish standards based on the HCl detection level of Method 321, nor should they

establish standards for any compounds at their corresponding method detection levels.

 The commenter noted that there is a difference between the detection limit and practical 

quantification limit. There is also a difference between test methods and continuous 

monitoring systems, although EPA has proposed a continuous monitoring requirement 

and cited test Method 321.

 The commenter requested that EPA provide information regarding the differences 

between current detection levels and those established more than 15 years ago. 

 Detection limits are only useful to determine if the measurement is possible. Accuracy at 

the detection limit and values below is unknown. Therefore, proposing a standard at the 

analytical noise level will result in the inability to make accurate determinations of 

compliance.

Commenter 2855 stated that the current stated lower practical quantification limit for 

Method 321 still holds true. EPA has proposed to make changes to Method 321 without 

providing the information relevant to this change. It is the belief of the commenter and its 

member companies that the Practical Quantitation Limit (PQL) of Method 321 is between 1 ppm 

and 5 ppmv wet depending on how well the analytical system is optimized for HCl. These values 

are well within the guidance of 5-10 times the analytical detection limit, and any claims to the 

contrary must be proven through laboratory demonstrations and placed in the docket to this 

rulemaking.

Commenter 2855 stated that EPA had requested comment on which way to set the emission 

detection limit and to handle emissions information below the detection limit for use in this rule. 

The commenter stated in response that it is inappropriate to set any standard at a level where 

accuracy is unknown and thus demonstration of compliance is not defined. Further, EPA should 

not make changes to a promulgated test method (see changes to Method 321 in the Proposal at 

21,192) without first providing information in the docket for public review and comment.

Commenter 2855 stated that EPA should focus on measurement system capability and the 

availability of quality calibration materials in their standard setting. The commenter provided 

results of an analysis of analyte spike data showing sampling and analytical system biases when 

non-detect values were reported. The commenter stated that a concentration based standard 
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cannot be based on values such as detection limit that do not represent the difficult nature HCl 

measurement. The standard cannot be set at a level below the demonstrated system bias and 

should account for uncertainties in the calibration materials and the measurement system ability.

Response: We have provided additional information in the docket on detection limits (list) and 

have reviewed test data below detections limits. Sources can optimize their system to measure 

HCl and thus satisfy the PQL of Method 321. However, given that the final standard is 3 ppmv 

(for both existing and new sources), we believe that these concerns are addressed since the 

standard provides an adequate margin above the method detection limit to account for 

uncertainties of measurements near the detection limit.

Procedure 15

Comment: One commenter (2855) stated that PS-15 for FTIR Based CEMS is not appropriate 

for an HCl CEMS for portland cement applications. EPA requested comments on whether a 

CEMS can meet the requirements of PS-15 to measure HCl emissions. The commenter stated 

that EPA should develop a PS for HCl CEMS that does not mandate a specific technology, but is 

directly applicable to measurement of HCl. Additional problems stated by the commenter 

concerning PS-15 are:

 PS-15 is outdated and does not reflect how CEMS function. 

 PS-15 requires that an FTIR based CEM be used. It is unclear why an FTIR must be used 

when other technology is also available (i.e., GFCIR and TDL).

 Performance Specification-15 requires that a spectroscopist or operator be present on a 

nearly continuous basis to meet the performance criteria. 

 Performance Specification-15 is not specific for HCl and many of the technical 

requirements contained therein cannot be met for the 0.1 ppm to 2 ppm HCl 

concentration levels proposed by EPA. 

 Performance Specification-15 contains no requirements for: a) determining calibration 

error or drift; b) setting instrument span range; or, c) determining relative accuracy such 

as those contained in the Lilly documents.

 There are no NIST traceable HCl calibration gases as suggested by PS-15 at any

concentration level.

 There are no HCl calibration gases that can meet the 2% accuracy certification 

requirement contained in Section 9.1.1, particularly at the 0.1 ppm to 2 ppm 

concentration levels. 

 The highest quality HCl calibration standard available today is at a concentration level of 

5-10 ppm with a vendor certification of ±10%. The certification of the gas is by an FTIR 

calibrated with HCl gas standards prepared by the manufacturer. The certification has no 

independent anchor to NIST or other certifying organization.

 The requirements of PS-15 for data storage (one interferogram per hour, all absorbance 

spectra, all sample spectra, all background spectra, all CTS spectra, etc...) and spectral 

audits cannot be met with any available FTIR Based CEM systems. 
143

 PS-15 requires modification of the FTIR CEM analytical program when analytical results 

are not within ± 5 percent of the certified audit concentration for each analyte. FTIR 

CEMS programs are largely proprietary and cannot be modified by CEM operators at 

cement plants. Furthermore, FTIR CEMS cannot simply load outside software for 

analyses of audit spectra. This process must be tested with manufacturers of FTIR CEMS 

at the concentration levels proposed in this rule. 

 Requirements included in PS-15 assume the presence of a full time FTIR CEMS 

operator, which is impractical. 

Commenter 2915 disagreed with EPA’s proposed standards for the use of HCl CEMS:

 There is a lack of appropriate EPA performance specifications or quality assurance 

procedures for HCl CEMS;

 There are serious technical feasibility issues with implementation of the available 

technology; and 

 The proposed standards are at or below the CEMS practical quantification limit and/or 

the minimum detection limit of the analyzer.

Response: PS-15 is an FTIR CEMS procedure, but it does not specify any instrument. Any

commercially available FTIR instrument may be used as long as the performance specifications 

and quality assurance requirements of PS-15 are met. We recognize, however, that there are also 

non-FTIR technologies available to monitor HCl. We are planning to develop an HCl monitoring 

performance specification to address these additional technologies over the next year or so in 

advance of the compliance date of this rule; however, in the interim, owner/operators always 

have the option to petition the Administrator for an alternative testing approach for HCl under 

§63.7 (f).

The commenter is concerned that a spectroscopist or FTIR operator will need to be present on a 

nearly continuous basis at a monitoring installation. PS-15 has initial certification requirements 

that may require the assistance of a spectroscopist, as do most monitoring performance 

specifications, but we do disagree that PS-15 will require a full time operator. This issue has 

never been brought to our attention by users of this PS-15.

Regarding the comment that there are no NIST traceable HCl calibration gases, at least one 

specialty gas vendor (Air Liquide) sells high quality “Protocol” gases for HCl which are NIST 

traceable. These gases are currently available in concentrations ranging from 2.9 ppm to 5000 

ppm. For levels below this range, Method 205 (40 CFR Part 51, Appendix M) is available for 

operators to use prepare dilution gases in lower concentrations from the higher level cylinder 

gases.

As the cost of computer data storage continues to decrease, we do not expect the data storage 

requirements of PS-15 to be particularly burdensome. We do not have and are not planning to 

develop spectral audits for FTIR. Should we decide to develop them in the future, we will have 

to address the issue of proprietary software systems at that time.

Comment: Commenter 2855 stated that specific data storage requirements and data submission 

requirements that are subject to outside party interpretation should not be contained in any PS for 
144

a continuous monitoring system. For example, PS-15 requires that the data be submitted to EPA, 

and that EPA would interpret these data, and also provide audit spectra. The commenter stated 

that they were unaware that EPA had a spectroscopic branch that is developing these spectral 

audit materials, or that they are prepared to handle such data submissions in the future. If EPA is 

developing such materials, they should be provided in the docket so that the cement industry can 

evaluate how such a process could be handled. 

Response: As stated in the prior response, EPA has no plans to develop audit samples or audit 

spectra for the FTIR. If no audit materials are available, then an audit is not required. We believe 

the PS-15 requirements for spiking and other quality assurance requirements are sufficient in the 

collection of quality data. The data storage requirements are necessary due to the unique 

properties of FTIR. In particular, for the data analysis and review, the interferograms are critical 

in identifying and quantifying the target pollutants, and the pollutant results are not transparent to 

the data reviewer unless the raw data are available to allow reproduction of the results.

Comment: Commenter 2855 stated that EPA should develop an HCl monitoring PS or work 

with ASTM in such an effort should the HCl monitoring requirements prevail in this rule. The 

PS should employ analyte spiking as a means to both certify and validate the system rather than 

comparisons with Method 321 for Relative Accuracy testing. The commenter recommended 

documents EPA OTM 22 and EPA OTM 23 submitted by Eli Lilly prescribing the use of HCl 

CEMS at hazardous waste incinerators as a starting point for a new HCl monitoring performance 

specification.

Commenter 2915 stated that they do not believe that an HCl CEMS could meet PS-15, and EPA 

should develop appropriate, achievable performance specifications that are applicable to all the 

available technology and not dictate a monitoring technology such as FTIR. Once those are 

established, EPA should collect data with those technologies to determine whether they are 

appropriate for determining compliance with the proposed limit. If a technology meeting 

appropriate performance specifications is not capable of detecting or quantifying emissions at the 

level of the standard, the technology is not appropriate for use as a compliance method for that 

standard. The commenters provided a list of difficulties in using PS-15 for continuously

monitoring HCl.

Response: Facilities that desire to use monitoring technologies other than FTIR may utilize the 

General Provision to request approval to use an alternative method by providing the alternative 

specifications and QA/QC measures they would use. We agree there may be benefits to an 

ASTM process as well, and will work with them to evaluate such methods.

Comment: Commenter 2855 stated that EPA has specified use of Appendix F, Procedure 1 

along with PS-15. Appendix F, Procedure 1 was written for SO2, NOx and diluent CEMS (O2, 

and CO2). It is not directly transferrable to an FTIR CEMS monitoring HCl at extremely low 

concentration levels. Appropriate on-going quality assurance procedures are needed.

Response: We have revised the QA procedures to accept values up to 20 percent of the emission 

limit.
145

Comment: Commenter 2855 stated that the initial compliance demonstration procedures for HCl 

emissions from kilns or kilns/in-line raw mills appear contradictory and should be revised to be 

consistent with the proposed emission standards and 30-day rolling average. Section 

63.1349(b)(6)(ii) is inconsistent specifying a performance test duration of 24-hours, and 

requiring calculations of the daily average HCl concentrations from the hourly averages during 

the performance test. This is inconsistent with the language in the preamble and in §63.1343(a). 

Response: The 24-hour period is consistent with the RATA, which is used to demonstrate that 

the CEMS is operating properly. In this case, operation while the raw mill is on, is the only

requirement and the final rule has been revised to reflect this condition. Initial compliance is 

determined by the first 30 days of data.

Comment: One commenter (2855) stated that the initial performance demonstration should be 

based on a properly calibrated and compliant CEMS (if such a system becomes available that is 

capable of accurate measurements at the level of the HCl emissions) and the initial performance 

test result must be based on the calculated average HCl concentration for 30 kiln operating days. 

A definition for kiln operating day must be established and must reflect a specified number of 

hours of kiln or raw material dryer operation at normal production conditions. Days with fewer 

operating hours than a kiln operating day should not be included in the 30 day average. There 

should be no specification for separate tests for mill-on and mill-off for in-line raw mills.

Response: We agree that a definition of “kiln operating day” is needed and have added one to 

the final rule. We also agree that a raw mill off test is not required.

Comment: One commenter (2855) stated that the initial compliance demonstration procedures 

for HCl emitted from sources not controlled by a wet scrubber specifies a performance test 

duration and conditions that are not appropriate. Furthermore, 40 C.F.R. 

§63.1349(b)(6)(ii)(2008) states that initial compliance shall be demonstrated by conducting 

separate performance tests for in-line kiln/raw mills with the mill operating and with the raw mill 

off. This would require the facility to run in a mill-off condition for 24 hours, which is not 

possible. There should be no specification for separate initial compliance tests for mill-on and 

mill-off for in-line raw mills.

Response: We agree that a raw mill off test is not required and have changed the final rule to 

reflect this.

Comment: One commenter (2901) stated that EPA did not follow the Agency’s own protocols 

in proposing to change the practical lower quantification range of Method 321. 

Response: We believe we have adequately followed protocol in proposing changes the M321 

through this notice and comment rulemaking process.

Monovents

Comment: One commenter (2888) proposed that monovent facilities stack test for HCI, using 

EPA approved methods, on the same 30-month frequency as required for Dioxin/Furan testing 

under the current Portland Cement Maximum Achievable Control Technology (PC MACT).
146

Response: Sources equipped with scrubbers are required to test every 5 years. Such sources 

would have to construct a stack for testing. However, where sources use CEMS, we believe the 

current monitoring methodology is appropriate. Sources may request alternative performance 

testing requirements under the General Provisions to address site specific circumstances.

Clarifications

Comment: One commenter (2845) stated that §63.1343(b)(6) and §63.1343(c)(6) should be 

clarified to state that the HCl standard is corrected to 7 percent oxygen based on a 30-day rolling 

average.

Response: We agree and have made the suggested clarifications.

Comment: One commenter (2845) stated that §63.1350(q)(2) should provide specific 

requirements rather than reference to 40 CFR part 63, subpart SS, which may change in a manner 

that could make it inappropriate for a kiln system. The commenter provided detailed language to 

include in this section.

Response: While there are merits to using cross references, in this case we agree to add 

information specific to this rule to avoid the use of a cross reference.

Coal mills

Comment: One commenter (2910) asked that EPA clarify in the proposed revisions that in-line 

coal mills that vent directly to the atmosphere be exempt from installing or operating an HCl 

CEMS. The commenter stated that they knew of no basis for concluding that coal drying would 

increase the HCL concentration in the in-line coal mill exhaust. The commenter stated that 

monitoring the concentration of HCl in the main stack would be an appropriate way to measure 

compliance with the HCl standard. 

Response: We agree and have clarified the final rule accordingly.

2.7.5 Impacts

SO2 scrubbers and HCl control

Comment: Several commenters (2845 and 2900) stated that the scrubbers that would be used to 

control HCl are generally designed to control sulfur dioxide, not HCl. Vendors of HCl scrubber 

systems indicated that the system they would install would be designed for SO2, not HCl, if SO2

is present in the flue gas. The limited number of wet scrubbers in the U.S. on cement plants are 

designed to remove SO2, and are not intended to be used to comply with and HCl limit.

One commenter (2844) stated that there is little experience with scrubbers designed to control 

both SO2 and HCl. The commenter stated that based on limited short term HCl data, many kilns 

have preliminary HCl levels that will require much greater control.

Several commenters (2845 and 2900) stated that there are no data to support the conclusion that, 

under various conditions, a wet scrubber designed to utilize lime will provide the required 
147

collection efficiency to meet a 2 ppm emission standard. One commenter (2845) provided 

information about vendors’ HCl scrubbers, stating that the systems that can provide 99 percent 

control of HCl use NaOH as the scrubbing media. These systems are installed for applications 

that have been producing little if any SO2, and the inlet HCl concentrations are substantially 

higher than would be typical in cement plants. Because of product quality/specifications and 

economic concerns, NaOH would not be a reasonable reagent for cement kilns. Lime is easily 

obtained by cement plants, but NaOH would have to be purchased. Neither the portland cement 

industry nor the Agency have any data to support the conclusion that a wet scrubber designed to 

utilize lime will provide the required collection efficiency to meet a 2-ppm emission standard 

when SO2 is present in the flue gas and the inlet HCl concentration is very low. 

Commenter 2889 disagreed with EPA’s estimates of wet scrubber efficiencies of 99 to 

99.9 percent. The commenter notes that at the lower HCl concentrations found in cement kiln gas 

streams, it is unlikely that a wet scrubber could achieve those efficiencies.

Response: We agree that the wet scrubbers currently on U.S. cement plants are designed to 

remove SO2, rather than HCl. However, an EPA review of HCl emissions from 21 plants 

indicated an average concentration of 12 ppm, and a maximum concentration of 55 ppm. 

Therefore, required HCl removal efficiencies to meet the 3 ppm emissions standard are expected 

to be much lower than 99 percent for virtually all kilns. A preliminary review of data gathered 

from a 2010 Information Collection Request (ICR) for Electrical Generating Units indicates that 

wet scrubbers utilizing lime will be able to provide the necessary collection efficiency to meet 

the 3 ppm emissions standard. We also think that test data from the secondary aluminum industry

regarding the HCl removal by lime-coated fabric filters (e.g., Docket A-92-61, Item II-A-9) 

indicate that the 3 ppm emissions standard can be achieved by alternatives to scrubbers.

Baseline HCl emissions

Comment: One commenter (2845) stated that for HCl, EPA assumed that all kilns without 

recent test data would emit at the average rate observed across those relatively few kilns for 

which test data were available. While this may be true on average, this approach ignores the 

large variability that undoubtedly exists across untested kilns in terms of their actual HCl 

emissions rates. Some of the kilns to which EPA applies the average HCl emissions rate will in 

fact have high emissions and will need more intensive and costly HCl controls; EPA fails to 

accurately represent total control needs across the entire industry by missing these kilns that have 

emission rates well above the average.

Response: It is true that kilns may have emission rates above the average, and, therefore, may

require more costly controls. However, there are also kilns that have emission rates below the 

average, and, therefore, would require less costly controls. Data available to EPA indicated that 

there were more kilns with HCl emissions lower than the average rate utilized by EPA in cost 

calculations than there were kilns with HCl emissions above the average rate. Therefore, we 

believe the cost calculations are accurate, if not overestimating the total control costs for the 

industry.
148

Achievability using wet scrubber

Comment: One commenter (2900) provided a summary of information about one of their plant’s 

wet scrubbers. Information includes water and power use, costs, and HCl stack emission data. 

Prior to the installation of the scrubber, the plant conducted extensive tests in 2000 for purposes 

of evaluating HCl emissions from the various stacks. The data from 2000 demonstrates that the

HCl emission rate as lb/hr was doubled when the raw mill was shut down and indicates a 

scrubbing effect through its operation. The data taken in 2006 using similar methods showed that 

the plant experienced some reduction in HCl emission but not enough to achieve the EPA limit at 

less than 2.3 ppmvd at 7 percent oxygen. A data point was not found for the raw mill down 

condition. It is expected that the results will be less with the operation of the scrubber than the 

data point in 2000; but higher than the new EPA limit. Both the raw mill running and down 

conditions will likely be noncompliant with the new limit. The commenter noted that the 

scrubber at their plant was set at 5.5 to 6.5 for strictly SO2 control, and that the set point was well 

below the 8 to 10 pH that the commenter stated is needed for HCl control. As this scrubber is 

utilizing water, limestone, and some lime concentration present in the stone, it can be surmised 

that the EPA’s limit is difficult to achieve even with the best available scrubber technology.

Response: We believe that a preliminary review of data gathered from a 2010 Information 

Collection Request (ICR) for Electrical Generating Units indicates that wet scrubbers utilizing 

lime will provide the necessary collection efficiency to meet the 3 ppm emissions standard.

Furthermore, because the HCl standard is established at a level higher than all measured values 

(to account for the inability to reliably measure any lower standard) and measured based on 30-

day averages, it provides an ample compliance margin. The 30-day averaging period assures that 

several operating cycles of raw mill on and off are included in each average, thereby averaging 

them out over the 30-day period.

Water availability for scrubbers

Comment: Several commenters (2845 and 2941) stated that wet scrubbers are highly waterintensive, and based on the locations of many of the cement plants, obtaining additional water 

rights could be very difficult, particularly for plants located in states where water rights issues 

have been contentious. The commenter provided several estimates of water use, including an 

estimate for a typical cement plant of 460 million gal/yr, and an estimate that a scrubber will 

require, on average, 30 million gallons of water annually.

Response: As noted in the preamble, we are not mandating wet scrubber control technology in 

this rule. Other control techniques are available (hydrated finely ground lime, spray dryers, fuel 

and additive switching) that we believe would allow a cement kiln to meet the HCl emission 

limits in areas where sufficient water for a wet scrubber is not available. Although we have no 

cost data available for these alternative control techniques (some of which would be sitespecific), we anticipate that these control techniques would be no more expensive that a wet 

scrubber.
149

Scrubber costs are underestimated

Comment: Several commenters (2830 and 2845) stated that EPA has underestimated the cost of 

wet scrubbers to capture HCl, and there will be problems if a facility uses both a wet scrubber 

and a RTO in series. If the proposal for HCl is implemented, wet scrubbers will need to be 

installed at many of the cement plants. Wet scrubbers are designed such that the flue gas exiting 

the scrubber is saturated. As a result, the exiting flue temperature will be 160°–180°F. Therefore, 

plants that install these scrubbers will either need to reheat the flue gas to prevent condensation 

in the stack and provide flue gas buoyancy, or it will be necessary to line the stack with a 

material to withstand continuous water condensation. In either case, this will be an added cost to 

the plant. If natural gas were used to reheat the flue gas from 160° to 225°F, the theoretical plant 

generating 200,000 dry standard cubic feet per minute (dscfm) would generate an additional 

7,500 tons CO2/year.

According to commenters 2830 and 2845, if an RTO is required because of THC emissions, the 

exhaust exiting the wet scrubber enters the RTO fully saturated with moisture, meaning that as it 

is heated, it passes through the temperature range with the highest corrosion potential (above the 

water dew point and below the acid dew point). Thus, very costly nickel alloys must be used at 

certain areas within the RTO. Also, in designing the RTO, if the heat exchanger is designed to 

achieve high thermal efficiency (low gas consumption), then the RTO outlet temperature will be 

below the acid dew point. As a result, all outlet ducting and the stack must be resistant to acid 

condensation and high levels of corrosion. If the outlet temperatures are raised above the critical 

acid dew point temperature, then the RTO will consume very large quantities of natural gas. 

Therefore, the choice forced upon the kiln by the proposed rule is either high energy costs or 

high material (alloy) costs.

Response: As noted in a previous response, we believe that the wet scrubber costs are accurate, 

if not overestimated, for the reasons cited. The wet scrubber and RTO costs were calculated 

based on actual costs from the industry for those systems, and, therefore, should already account 

for the factors mentioned by the commenter. Furthermore, as noted in the preamble, the wet 

scrubber/RTO combination has already been demonstrated in cement kiln applications.

Accounting for scrubber waste handling

Comment: Several commenters (2841, 2845, and 2889) stated that there will be problems with 

the solids and liquid handling of wet scrubbers. The commenter provided an overview of the 

wastes associated with wet scrubber operation. The commenter’s concerns include: 

 Plants will need to dispose of some or potentially all of the sludge. EPA has assumed that 

the solids would be recycled to the finishing mill, but the chemistry of the sludge will be 

site specific and may not allow recycling. Disposal of solid waste would require 

additional permits.

 Dewatered solids from the scrubber have a moisture content of 25% to 35%. This 

material is difficult to handle in the finish mill and its associated classifier. Furthermore, 

the solids from a wet scrubber are not composed strictly of gypsum (calcium sulfate). The 

waste material includes sodium and potassium salts. There will also be some calcium 
150

sulfite. There are limits to the concentrations of these contaminants that can be included 

in the cement product.

 Because of recirculation of the slurry, the concentration of chlorine in the slurry liquid 

can rise to high steady-state concentrations, requiring wastewater treatment.

 The costs for water treatment imposed by the proposed rule would be at least $50,000 per 

year, not taking into account total dissolved solids (TSS) or biochemical oxygen demand 

(BOD) costs.

Response: Our wastewater and solid waste impacts estimates for wet scrubbers were determined 

based on information from industry and, as such, should already account for the situations cited 

by the commenter. As noted in the preamble, all of the facilities currently using wet scrubber mix 

the gypsum created in the scrubber with clinker in the finish mill and were assumed to also 

account for other waste materials that accumulate during the normal operation of the facility. As 

noted in the preamble, there are four facilities (five kilns) that currently use wet scrubbers that 

report no water releases at any time, such as that cited by the commenter. We requested comment 

in the Portland Cement NESHAP proposal on the potential for water releases due to wet scrubber 

system purges and any regulations that might apply. Though commenters raised concerns of the 

possibility of water impacts, they did not provide a rationale of why it would be expected, when 

it is not occurring at the four facilities that currently use wet scrubbers, due to their on-site reuse 

of water. If discharges did occur, there would be a potential for water quality issues. But given 

these facts, we believe our estimate of no water quality impacts resulting from production of 

wastewater by wet scrubbers is reasonable. The sludge that is generated is used again in the 

process, so there is no cost of disposal associated with sludge. 

HCl emissions data, Table 5 of Preamble

Comment: One commenter (2863) stated that Table 5 in the preamble outlines the available HCl 

data for the 27 kilns for which Method 321 data were available. Ash Grove’s Durkee plant is 

identified as source #26 on that list with emissions of 34.68 ppm HCl. This is not correct. The 

Durkee plant’s HCl emission rate is 3.2 ppm (7 percent oxygen)—an order of magnitude lower 

than what is stated in Table 5. Portland cement kilns are not significant sources of HCl. 

Response: As noted in the preamble, the analysis for the HCl MACT floor was revised to 

remove errors identified in comments on the proposal, including this error.

Dry scrubbers

Comment: One commenter (2889) stated that there are problems associated with spray dryer 

absorbers or lime injection-based dry scrubbers recommended for arid regions. A review of 

recent boiler BACT analyses summarized in the RBLC Clearinghouse indicates that the HCl 

removal efficiencies are well below the 99 percent levels assumed by EPA. Furthermore, both 

types of dry scrubbers generate significant quantities of solid waste.

Response: EPA expects that the HCl removal efficiencies needed to comply with the 3 ppm HCl 

emissions standard will be well below 99 percent for virtually all kilns. Regarding the solid 

waste argument, as stated in the preamble, the PM captured in the kiln fabric filter (cement kiln 

dust) is essentially recaptured raw material, intermediate materials, or product. Based on the 
151

available information, it appears that most captured PM is typically recycled back to the kilns to 

the maximum extent possible. Therefore, we estimate that any additional PM captured will also 

be recycled to the kiln to the extent possible.

2.8 PM Standards

2.8.1 Legal Issues

MACT-on-MACT

Comment: Many commenters (2830, 2832, 2841, 2844, 2845, 2858, 2859, 2863, 2864, 2874, 

and 2914) stated that EPA lacks the authority to promulgate new PM standard using the MACT 

floor approach because EPA issued new and existing source NEHSAP for PM in 1999. Once the 

NESHAP is established, the CAA §112(d)(6) requires any revision to the standard to be 

accomplished using a technology review and not using the process proposed by EPA in this 

rulemaking. The proposed EPA standard in this rulemaking leads to a MACT-on-MACT 

approach which results in a floor that is much more stringent than it would have been if EPA had 

used emissions data from sources that had not already complied with the 1999 PM standards. 

Response: This is factually incorrect. If EPA properly established MACT for PM using the 1999 

data base, the standard for existing and new sources would be higher than the standard adopted 

in today’s rule, as explained in the preamble to the final rule (although EPA considers its current 

data base to be more representative, and so is using it to amend the standard).

Comment: Due to the inappropriateness of EPA’s proposal and the fact that the 2000 remand 

did not address PM at all, the commenters urge EPA to maintain the 1999 PM standard. 

Commenter 2864 argued that EPA does not have the authority under the CAA to completely 

recalculate PM MACT floors for cement plants where the initial floors were upheld. Although, 

EPA has the authority to revise the PM MACT standards for the industry, EPA must do so in 

accordance with §112(f) or §112(d)(6) without recalculating the floors. Because EPA has failed 

to conduct the analyses necessary under those provisions, it has no authority to revise the PM 

MACT standards for either existing or new cement plants.

Response: As stated in the preamble to the final rule, MACT-on-MACT is a misnomer because 

the 1999 standard simply does not represent MACT. For the reasons stated in the preamble, EPA 

does not see that it is barred from amending that standard here to make a proper determination of 

MACT.

2.8.2 Adequacy of Floor Determinations (Existing and New)

Support for PM standards

Comment: Several commenters (2898 and 2911) supported EPA’s proposed standards for PM 

and EPA’s proposed standards for area source cement kilns under §112(d)(2)-(3).

Several commenters (2786 and 2898) stated that particulate metal emissions from cement plants 

may pose health risks at very low levels and therefore stringent emission controls are needed. 
152

Cement facilities are sources of the non-volatile metal HAPs antimony, cadmium, lead, 

selenium, chromium, arsenic, nickel and manganese. 

Commenter 2928 supported the proposed emission standards for PM.

Response: EPA acknowledges the commenters’ support.

Comment: Two commenters (2845 and 2859) said that EPA has not promulgated any

regulations requiring PM CEMS at any source category due to its inability to address 

fundamental technical and policy issues and must resolve these issues through rulemaking before 

requiring PM CEMS at any cement plants. Furthermore EPA has not performed a legitimate 

technical analysis of emissions variability and compliance determination uncertainty to allow the 

use of PM CEMS for determining continuous compliance with a PM limit at cement plants.

Response: We reject the commenters’ assertions that PM CEMS have not been required via 

rulemaking because of unresolved fundamental technical or policy issues. Concerns about PM 

CEMS were identified and addressed prior to the January 2004 publication of Performance 

Specification 11 and Quality Assurance Procedure 2 for PM CEMS (69 FR 1786, January 12, 

2004). As mentioned in that rule’s preamble, “...we believe that the PM CEMS field 

demonstrations completed to date encompass a range of operating conditions and emission 

characteristics...” including those exhibited by sources such as cement kilns.

Moreover, we disagree with the assertion that our analysis of PM emissions variability is not 

legitimate, yielding an overly-stringent PM emissions limit. The PM limit is based on our 

analysis of PM emissions from test data, adjusted from an hourly to a 30-day averaging period 

and further adjusted for variability. As mentioned in the preamble to the Credible Evidence Rule 

(62 FR at 8314, February 24, 1997), we have addressed and continue to address concerns about 

perceived “...limited number and distribution of test runs and the inherent variability in levels of 

emissions...” by a number of approaches, including changing emissions averaging periods.

Further, a statistically-based adjustment to account for emissions variability, and which, in this 

case, increases the numerical value of the standard (and its longer averaging period) by fifty 

percent, does not make the standard more stringent.

Variability

Comment: Several commenters (2830, 2844, 2845, 2859, and 2864) stated that because the data 

in the proposed NESHAP is based on a limited data set (3-hour stack tests) that short term tests 

will not address the variability issues. The commenter analyzed EPA’s released PM data and 

found that EPA did not use all available PM data and according to the commenters, EPA used an 

inappropriate statistical analysis (UPL instead of upper tolerance level UTL). The commenter 

suggested that when an appropriate statistical analysis using all of the EPA’s PM data is used, 

the PM MACT standard should be 0.092 lbs/ton of kiln feed for existing sources and 0.0625 

lbs/ton of kiln feed for new sources. Commenters 2845 and 2859 submitted PM data as part of 

their comments on the proposed NSPS rules for portland cement.

Commenters 2845 and 2864 stated that the data set used to set the MACT floor was too small. 

The commenter recalculated the PM floors using additional data, and presented data showing the 

relationship between bag life and PM emissions. The commenter stated that it is important that 
153

EPA includes as part of the MACT floor the operational variability experienced due to filter life 

and the baghouse itself that EPA needs to include as part of the MACT floor. The commenters 

provided graphs showing the effects of age on baghouse performance.

Response: In its comments, commenter 2859 stated that EPA ignored one of two data points. 

They stated that EPA selected 0.0108 lb/ton clinker and ignored a data point of 0.032 lb/ton 

clinker. The commenter misunderstood how EPA calculated PM emissions for the Sugar Creek 

kiln; EPA did not select one data point over another. The PM data for that kiln was obtained 

from the Missouri Department of Natural Resources (MDNR) and was used to calculate average 

emissions for that kiln. The Sugar Creek kiln is one of the six MACT floor kilns used in the 

analysis of the MACT floor for PM. The data for the Sugar Creek kiln used in the MACT floor 

analysis is presented in the following table.

Lafarge Sugar Creek, PM Emissions: MDNR Data for 2002 and 2007

Roller Mill On

Run Date PM (lb/hr) Kiln Clinker Production (tph)

PM Rate 

(lb/ton 

clinker)

103* 8/7/2002 0.044 125.33 0.0004

105* 8/8/2002 0.587 119.37 0.0049

101* 10/30/2002 0.967 113.82 0.0085

111* 9/5/2007 2.52 127.00 0.0198

112* 9/5/2007 1.7 126.93 0.0134

113* 9/5/2007 1.09 126.93 0.0086

AVG (mill on) 0.0093

Roller Mill Off

Run Date PM (lb/hr) Kiln Clinker Production (tph)

PM Rate 

(lb/ton 

clinker)

101* 8/6/2002 8.118 124.42 0.0652

104* 8/7/2002 1.823 120.27 0.0152

106* 8/9/2002 1.746 120.72 0.0145

101* 11/6/2007 5.22 119.12 0.0438

102* 11/6/2007 7.24 123.59 0.0586

103* 11/6/2007 4.84 118.32 0.0409

AVG (mill off) 0.0397

WTD AVG (Mill on & off) 0.0108

In their comment, commenter 2859 provided PM test results for 2002 and 2007 as well as new 

PM run data for tests conducted in 2004, which EPA did not have when it was the developing the 

MACT floor for PM. The commenter’s PM data for 2002 and 2007 is essentially the same as the 

data set we used with minor differences due to differences in kiln feed rates. The individual run 

data submitted by commenter 2859 are presented below.

Lafarge Sugar Creek, PM Emissions: Lafarge Data for 2002, 2004, 2007

Roller Mill On
154

Lafarge Sugar Creek, PM Emissions: Lafarge Data for 2002, 2004, 2007

Date

Filterable PM 

(lb/hr) Kiln Production (tph)

PM rate 

(lb/ton clinker)

8/7/02 0.04 127.87 0.0003

8/8/02 0.59 121.80 0.0048

10/30/02 0.97 116.18 0.0083

5/20/04 3.02 117.95 0.0256

5/20/04 2.51 125.77 0.0200

5/20/04 2.65 126.10 0.0210

5/20/04 2.27 121.14 0.0188

5/20/04 2.76 108.80 0.0253

5/20/04 2.69 108.80 0.0248

6/25/04 3.30 126.10 0.0262

6/25/04 3.52 126.10 0.0279

6/25/04 3.41 125.88 0.0271

7/14/04 3.79 125.99 0.0301

7/14/04 3.97 126.10 0.0315

7/14/04 3.52 126.10 0.0279

9/5/07 2.52 129.52 0.0195

9/5/07 1.70 129.41 0.0131

9/5/07 1.00 129.52 0.0077

AVG (mill on) 0.0200

Roller Mill Off

Date

Filterable PM 

(lb/hr) Kiln Production (tph)

PM rate 

(lb/ton clinker)

8/6/02 8.12 126.98 0.0639

8/7/02 1.82 122.69 0.0149

8/8/02 1.75 123.13 0.0142

5/18/04 4.90 128.86 0.0381

5/18/04 3.79 126.54 0.0300

6/29/04 9.07 126.10 0.0719

7/15/04 8.02 126.10 0.0636

7/15/04 8.95 126.10 0.0710

8/12/04 12.57 129.52 0.0971

11/6/07 5.22 117.06 0.0446

11/6/07 7.24 111.22 0.0651

11/6/07 4.84 117.17 0.0413

AVG (mill off) 0.0513

WTD AVG (Mill on & off) 0.0216

Adding in the 2004 test runs increases the weighted average (assuming the raw mill is on 95 

percent of the time and off 5 percent of the time per the MDNR) for the kiln from 0.0108 lb/ton 

clinker to 0.0216 lb/ton clinker. The kiln is still among the top six performing kilns.

One commenter (2845) stated that they collected additional PM data and combined the new data 

with the EPA data set to create a new MACT data set consisting of a total of 319 runs/test data 

points for 47 kilns. The commenter’s data included the number of runs/data points, the minimum 

and maximum PM values, and the mean PM emissions in lb/ton clinker. Based on average 

emissions for each kiln in the new data set, the commenter identified a new list of the top 6 kilns 

with average PM emissions for the 6 MACT floor kilns of 0.024 lb/ton clinker. Commenter 2864 
155

concurred with the reanalysis of the MACT floor using the new MACT data. EPA evaluated the 

new data and found shortcomings that led us to not include the data in our analysis for the PM 

MACT floor. The shortcomings identified include the following: 

 Individual run data from which the commenter calculated average emission rates were 

not included preventing us from fully evaluating the emissions data or the average 

emissions they presented. 

 When EPA selected the top performing kilns, it used the average PM emissions for each 

kiln and ranked them from lowest to highest. In the case of kilns with raw mills, EPA 

calculated the weighted averaged emissions using test run data during raw mill on and 

raw mill off periods. Because a raw mill operates 85-95 percent of the operating time, the 

PM emissions during the raw mill on period will dominate the weighted average. It 

appears that the commenter calculated a simple arithmetic mean rather than a weighted 

average for kilns that have raw mills. This was determined because for two kilns with raw 

mills that only reported two values for each kiln, the commenter calculated the simple 

arithmetic mean of the two values. Because PM emissions tend to be lower when the raw 

mill is on and because the raw mill is typically on 85-95 percent of a kiln’s operating 

time, calculating a simple arithmetic mean as the commenter did, will likely overstate 

emissions. Because individual test runs were not supplied, it was not possible to 

recalculate the weighted averages for those kilns with raw mills. Among the six MACT 

floor kilns identified by the commenter, four operate raw mills. 

 No explanation was given for excluding the Lehigh, Union Bridge kiln from its data set 

or for dropping it from the top 6 kilns used in EPA’s analysis. The average emissions for 

Lehigh, Union Bridge would put it in the top 6 in the commenter’s set of new MACT 

floor kilns.

 The commenter’s data set for Lafarge kiln 2 at Whitehall consisted of 13 data points 

whereas we used 15 test runs.

Commenters 2845 and 2864 commented that EPA’s PM limits did not account for declining 

fabric filter performance over time. Commenter 2864 provided graphical evidence for one of its 

kilns that it claimed showed that PM emissions increased with aging bags. The graph indicates 

low emissions during the initial performance test as well as several years later after replacing all 

of the baghouse bags. Following replacement, PM emissions increased after installationof new 

bags and remained high even when the bags were again replaced. Contrary to the commenter’s 

claim, performance declined even when new bags were installed. Based on the information 

provided by the commenter, it appears that there were factors other than aging bags that 

contributed to declining PM performance. EPA has reviewed PM test data for several kilns over 

time and have concluded that PM emissions can be highly variable. This variability can even be 

evident in consecutive test runs on some kilns. The first figure below shows the highly variable 

PM test results from a single for nine test runs over a 3-day period. The second figure plots the 

average test results for six different kilns over varying number of years. From these data, there 

are no clear indications that baghouse performance necessarily declines over time, rather it 

indicates that performance is variable. Obviously it will be necessary for cement plant owners 

and operators to operate and maintain their baghouses in peak condition to comply with the new 

PM limits. But EPA rejects the commenters’ arguments that baghouse performance necessarily 

declines over time and that the PM limits should be less stringent to account for this.
156

Condensable PM

Comment: Several commenters (2845 and 2874) stated that it would be inappropriate to regulate 

condensable fraction of PM2.5 for the following reasons:

 Because there are known problems with the test method 202 which is used to determine 

the emissions for PM2.5 and the little data EPA has is based on questionable AP-42 

factors which is based on several tests, EPA used limited available data that were of very

uncertain accuracy.

 The EPA did not show that listed HAP can be found in the condensable fraction and 

therefore cannot reasonable use condensable PM as a HAP surrogate under the authority 

of CAA §112(d).
157

 If HAP existed in condensable PM, they would be controlled by other means which 

include PM control devices for filterable PM, mercury which is already directly 

regulated, and organic HAP are regulated through the THC surrogated. Therefore, there 

would be no need to include condensable PM as part of the PM standards.

 EPA would need to propose PM standards because the current proposed standards are 

based only on filterable PM and not both filterable PM and condensable fraction of PM.

Response: The PM limits address filterable PM, including PM2.5 and PM10, but not condensable 

PM. We do not have information on emissions of condensable PM from cement kilns sufficient 

to set emission limits and the limited information we do have is highly uncertain. We also 

believe that these emissions will be controlled to some degree via controls on HCl in the 

NESHAP and SO2 in the NSPS. EPA has recently promulgated a new test method for 

condensable PM (revised Method 202) which will allow for more reliable assessments of 

condensable PM. We anticipate that data more representative of condensable primary PM 

emissions will be available at the time of the next review of the NSPS.

Combined stack gases

Comment: One commenter (2841) stated that the proposed standards are based on a kiln stack 

or some estimated number based on the flow apportioned from a kiln and clinker cooler. This 

does not address situations, such as those where additional sources of particulate are included 

into the same duct system leading to one stack. In order for facilities to design more efficient 

manufacturing operations, other configurations are likely and should be encouraged. In addition, 

using a grain loading standard is easily measured and can be monitored more effectively.

Another commenter (2845) stated that the MACT floor for combined stacks (new or 

reconstructed kiln or in-line kiln/raw mill) should be calculated based on all available data and 

should subcategorize PM standards by different kiln types. The alternative PM standard should 

provide for including other exhaust gas streams in the main stack such as coal mills. Facilities 

should have the option of meeting a grain loading based standard instead of the lbs PM/ton of 

clinker standard, if that is retained by EPA. The rule should be worded such that it is clear that 

for combined exhausts, the gas flow and PM testing only needs to be measured at the stack when 

using the alternative PM limit. The rule should be worded such that it is clear that PM testing 

will not need to be conducted in mill-on/mill-off conditions.

Response: Regarding these two comments, facilities have the option to petition the EPA 

Administrator for a site-specific emissions standard for the situations described above (e.g., 

including additional sources of particulate in the same duct system leading to one stack, meeting 

an alternative grain loading based standard), as long as the facility can demonstrate that the 

alternative standard will achieve an emissions reduction equivalent to that obtained under the 

promulgated standard. 

Clinker coolers

Comment: One commenter (2845) stated that §63.1345(a) standards for clinker coolers should 

not be changed, remaining at 0.10 lb per ton of feed (dry basis).
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Response: We disagree with this comment for the reasons discussed in the in the preamble 

regarding the PM limit for kilns. Therefore, we are setting the same PM emissions limits and 

compliance requirements for both clinker coolers and kilns.

Increased PM with use of wet scrubbers

Comment: One commenter (2889) stated that EPA has not adequately considered the emissions 

of particulate matter from wet scrubbers due to reentrainment of solids-containing droplets from 

mist eliminators. Subcategorization is needed with respect to particulate matter emissions from 

wet scrubber-controlled cement kilns. Based on similar units in the lime industry, it is apparent 

that this will be a significant problem. In fact, Subpart AAAAA includes a higher particulate 

matter allowance for wet scrubber-controlled lime kilns than for fabric filter controlled lime 

kilns. Without a similar form of subcategorization, there will be an incentive not to install wet 

scrubbers and instead use a less efficient dry scrubbing system.

Response: The commenter is confused about the structure of subpart AAAAA. First, the 

separate higher PM limits in subpart AAAAA of part 63 are there to permit facilities with wet 

PM scrubbers installed before 2004 to continue using them but to require more effective PM 

control for newer units. The rule recognizes that wet PM scrubbers are not as effective as fabric 

filters for PM control. Secondly, wet scrubbers designed and operated to provide that gaseous 

SO2 or HCl react with caustic slurries are fundamentally different from wet scrubbers designed 

to remove PM (e.g., Venturi scrubbers). Acid gas scrubbers are not intended to be PM removers; 

any collection of PM in an acid gas scrubber is incidental to the primary purpose and probably 

minimal. The commenter is correct that a poorly operating mist eliminator downstream of an 

acid gas scrubber may produce PM emissions that could affect overall PM control. The source 

must provide effective mist elimination in order to maintain compliance with not only the acid 

gas emissions limit but to avoid increasing PM emissions. 

Commenter 2900 provided data on particulate emissions before and after installation of a wet 

scrubber. The data indicated particulate emissions decreased. EPA expects installation of 

scrubbers after fabric filters will result in slightly lower filterable particulate emissions than with 

fabric filters alone. We do not think that Subpart AAAAA cited by the commenter provides 

evidence that installing a scrubber downstream of a particulate filter results in higher particulate 

levels than a fabric filter alone.

2.8.4 Compliance Assurance

Performance of bag leak detection systems and other PM monitoring systems

Comment: Several commenters (2845, 2859, and 2887) stated that in proposing PM compliance 

assurance provisions, EPA did not, but should, conduct a technical evaluation of the 

applicability, installation, design, performance, certification, quality assurance and alarm level 

setting procedures for all PM monitoring approaches and then re-propose appropriate technical 

requirements for monitoring kilns, kilns/in-line raw mills, and clinker coolers using bag leak 

detectors (BLDs), Particulate Matter Detectors (PMD) and Continuous Opacity Monitors 

options. According to the commenters, EPA does not recognize that many BLD designs are 

inappropriate and inadequate for use under the varying effluent matrix and conditions, especially 
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at kilns/in-line raw mills nor does EPA acknowledge that technically superior and far more 

practical PM monitoring approaches have been developed for cement plants that burn hazardous 

waste. The commenters stated that the proposed PM monitoring provisions are inconsistent with 

the promulgated PM monitoring requirements for cement plants that burn hazardous waste (40 

CFR 63, Subpart EEE-2008), which includes provisions for the use of PMD on both Electrostatic 

precipitators (ESP) and fabric filter controlled cement. EPA appeared to be unaware that recent 

work at a cement plant with membrane coated fabric filters has demonstrated that continuous 

opacity monitoring system (COMS) can also meet the rigorous ASTM D7392-07 requirements 

for certification as a PMD. 

Response: At this point, we still find that BLD is an appropriate technology for PM monitoring.

We believe that sources will work with system vendors to install and use appropriate systems for 

kiln-specific conditions. We note that cement kilns that burn hazardous waste operate under 

different conditions than ordinary kilns. However, we will continue to review advances in PM 

monitoring technologies in general and will be happy to consider source-specific requests for 

alternative approaches. The rule already provides BLD as an alternative for PM CEMS.

Comment: Several commenters (2845 and 2859) stated that EPA has not demonstrated 

acceptable performance of BLDs to monitor kiln, kiln/ in-line raw mills at cement plants and has 

not developed necessary guidance for or technical requirements that will be necessary for a BLD 

to meet the requirements in the proposed rule. EPA has provided no guidance on appropriate 

alarm setting procedures, installation, operation, and quality assurance procedures and corrective 

action procedures and relevant validated procedures are not available from the measurement 

system suppliers for installations on cement kilns and kilns/inline raw mills. According to the 

commenter, in the selection of BLD devices it is clear that the most widely used probe type 

BLDs (such as triboelectric, or probe electrification, or charge transfer devices) are unsuitable 

for use on kilns/in-line raw mills because the responses of these devices are proportional to the 

square or to the cube of the local gas velocity and are also affected by changes in effluent 

temperature, moisture content, and resistivity of the dust. All of these factors change when the 

raw mill operational status changes. 

Several commenters (2845 and 2859) stated that because EPA did not provide technical 

specifications, installation procedures, operation and maintenance procedures, quality assurance 

procedures, or alarm setting procedures or any relevant guidance for these issues for BLDs, the 

burden is on the user to develop this information. If EPA cannot provide technical requirements, 

criteria or guidance, then it certainly has no basis to review the site-specific plans for approval. 

With no established criteria or guidance, review by different regional offices or states as 

delegated authorities will likely result in different requirements and different interpretations, and 

confusion. The deadline for submission of the site-specific BLD plan is not explicitly stated. 

There is no time limit for EPA’s approval, no obligation for EPA to render an opinion as to the 

acceptability of the plan, no instruction to the user as to monitoring prior to receipt of approval, 

and no indication of the consequences in the event the plan is not approved. Until legitimate 

guidance and criteria are developed, the commenter stated that it is sufficient that site-specific 

monitoring plans be available for review. The commenters stated that, for the above reasons, the 

requirement to submit the site-specific plans for approval should be removed.
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Several commenters (2845 and 2859) stated that EPA needs to provide appropriate design and 

performance specifications so that manufacturers can certify that their BLD meets applicable 

criteria in order that the regulated user of such devices can rely on the manufacturer’s 

certifications. Without an appropriate design and performance specifications, there are no means 

available to the cement plant operator to verify claims made by the BLD vendor or manufacturer 

regarding detection capability. Plant operators cannot be responsible for the design or 

performance of these systems and cannot be expected to able to determine the technical validity 

of vendor claims, especially where there are in effect no regulatory or technical requirements.

Response: While there is not a formal performance specification, there is existing guidance on 

BLD. We have written a performance-based rule for sources to use to tailor operation of the 

BDL to meet the needs at each plant including variations in operation with the mill on vs. mill 

off. The final rule clarifies that the resulting plans must be kept on site. Submittal is not required.

There are several types of BDL and, as stated above, we believe that sources will work with 

system vendors to install and use appropriate systems for kiln-specific conditions. Sources have 

3 years to comply with the final standards and should use this time to ensure they are using a 

system that works well for their application.

Comment: Several commenters (2845 and 2859) had the following comments concerning BLD 

and alarms:

 The proposed requirements for recording the BLD output and setting the activating alarm 

are inconsistent with procedures actually used for contemporary BLD.

 EPA should remove the out-of-date requirement that the BLD should activate an audible 

alarm and use more up-to-date guidance which applies to settling alarm levels for the full 

range of BLD and fabric filter configurations that are found at cement kilns that burn 

hazardous waste. The proposal reflects bias to a particular manufacturer and particular 

approach which is not applicable to all cement kilns. The commenter provided several 

examples of what the commenter considered to be out-of-date requirements.

 The requirements to initiate procedures to determine the cause of every alarm within one 

hour and alleviate the cause of the alarm within three hours are problematic. EPA must 

revise its requirements to accommodate real-world conditions that cannot be avoided and 

EPA must recognize site-specific BLD monitoring plans will need to be revised as actual 

experience is gained from the use of these devices at kilns and kilns/in-line raw mills. 

The commenter provided examples to support their position. 

 The time allowed for alleviating the cause of a BLD alarm is not sufficient especially 

when a false alarm is due to malfunction of the BLD or an in appropriate alarm setting 

procedure.

 The requirement for audible alarms may be distracting and are unnecessary. The type of 

alarm should be at the discretion of the plant operator. The commenter stated that many

control rooms are equipped with visual alarms that the operator must acknowledge and 

respond to. These alarms include situations with far greater safety and emergency priority 

and consequences than BLDs alarms and are critical to operation of the plant. 

Response: We agree that an audible alarm is not required and have changed the final rule to 

reflect this. We have also provided additional time for the operator to determine the cause of the 
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alarm (3 hours instead of 1 hour) and up to 24 hours to alleviate the cause of the alarm (up from 

3 hours) to better reflect some of the complex situations that operators may face.

PM detectors

Comment: Several commenters (2845 and 2859) had the following comments concerning PMD:

 Because PMD are a technically superior and more practical alternative to BLDs, EPA 

should allow the use of PMD as an alternative to BLDs as is allowed for cement plants 

that burn hazardous waste under 40 CFR 63 subpart EEE.

 PMD should be allowed as an alternative to BLDs and/or ESP predictive monitors and 

the PMD alarm set-point should be established during PM source tests demonstrating 

compliance with the applicable PM standard.

 PMD avoid the problems with attempting to set qualitative alarms based on nearly 

instantaneous shifts in peak instrument responses, baseline shifts, or rates of decay, as is 

the case with BLDs. PMD provide an integrated average and warn the operator of the 

need for corrective action, before an exceedance has occurred. According to the 

commenter, EPA’s failure to allow the PMD under Subpart LLL causes redundant and 

unnecessary monitoring for cement plants that are not subject to Subpart EEE when not 

burning hazardous waste. For sources where the PM concentration can be varied, a series 

of tests should be allowed to determine the PMD output corresponding to the highest PM 

concentration which is demonstrated to meet the applicable standard. For sources for 

which the PM concentration cannot be varied (certain fabric filters) alternative 

procedures to determine the PMD output corresponding to the level of the emission 

limitation should be established. If future work demonstrates that a representative PM 

spiking approach can be applied to increase the PM level, the regulations should then be 

revised to allow such an approach.

 EPA should acknowledge that particulate matter detections systems (PMDS) and/or 

BLDs meeting ASTM D7392-07 are acceptable for monitoring because it was developed 

to fill the void in EPA requirements so that reliable instruments could be used at cement 

plants that burn hazardous waste. The practice provides a comprehensive set of design 

and performance specifications for a broad range of monitoring technologies specifically

intended for monitoring of PM at cement plants. In addition to technical requirements 

applicable to various cement plant configurations, the Standard Practice includes detailed 

approaches for setting PMD and BLD alarm set points that are more appropriate than 

those contained in EPA guidance. It is also important to recognize that:

– EPA was obligated to consider this ASTM standard under National Technology

Transfer Act, but apparently did not do so.

– EPA Office of Air Quality Planning and Standards (OAQPS) and/or Office of Solid 

Waste (OSW) representatives participated in the development of the voluntary ASTM 

D7392-07 Standard Practice for use at cement kilns that burn hazardous waste, 

offered comments during participation at meetings and through correspondence on 

various drafts, and raised no negative votes during balloting.
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– PMDS are superior to BLDs and are required by ASTM D 7392 to meet more 

rigorous specifications, do not suffer from subjective and interpretive alarm setting 

procedures, and should be allowed as an alternative.

– PMDS can be used on kiln stacks with co-mingled emissions (e.g., kiln/in-line raw 

mill and coal mill emissions) where as separate BLDs would be required for each 

baghouse.

– PMDS are far more practical and far more cost effective than PM CEMS and should 

be allowed as an alternative.

– Teledyne Monitor Labs (the major American manufacturer of COMS used at cement 

plants) has demonstrated that a contemporary LightHawk Model 560 transmissometer 

meeting ASTM D 6216-07 was able to meet the rigorous ASTM D 7392-07 PMD 

requirements based on field tests at a cement kiln burning hazardous waste equipped 

with high efficiency membrane coated fabric filters.

Response: PMDs were not considered in the proposal. We will consider requests to use PMDs 

on a case-by-case basis as an alternative to BLDs. An owner or operator who wishes to use a 

PMD as an alternative monitoring procedure must submit an application to the Administrator.

COMS

Comment: Several commenters (2845, 2859, and 2887) had the following commenter 

concerning COMS:

 COMS should be allowed as an alternative to PMDS and BLDS for both ESP and fabric 

filter controlled sources as an option that can be selected by the plant operator because 

they are a highly evolved, mature technology that is well understood by both cement 

plant operators and agency personnel. These devices are capable of detecting changes in 

PM concentrations downstream of both ESP controlled sources and fabric filter 

controlled sources and the need for inspection or corrective action of the PM control 

device. The selection of the most appropriate monitoring approach should be left to the 

plant operator and should include the use of COMS, where applicable, as an option.

 EPA’s attempt to dismiss COMS based simply on its opinion that they lack sufficient 

accuracy at the proposed PM emission limit levels is technically wrong and contrary to 

current work and other recently promulgated regulations. EPA provides no technical 

support for its dismissal of the accuracy of COMS and EPA appears to be completely

unaware of other developments that should have been considered. 

 EPA’s dismissal of COMS for units equipped with fabric filters is based on an incorrect 

assertion about measurement accuracy in favor of BLDs which are a purely qualitative 

measurement technique making absolutely no claim to accuracy and relying on 

subjective, interpretive, and un-documentable procedures to set alarm set points. EPA 

attempts to dismiss the long established and well understood use of COMS which 

include:

– Highly evolved ASTM D 6216-07 design and performance specifications for 

manufacturer certification. 40 CFR 60, Appendix B, PS-1 (2008) and the initial field 

certification procedures;
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– Well known quality assurance procedures and external audit capabilities using NIST 

traceable calibration materials to facilitate audits by users and control agencies;

– Daily zero and upscale calibration checks, lens cleaning requirements and other 

operation, maintenance, data recording, record keeping and reporting requirements 

contained in the general provisions of 40 CFR 60 and 63;

– A technology that is well understood by plant operators, plant technicians, control 

agencies, and instrument manufactures;

– Existing COMS requirements included in virtually every state operating permit for 

cement kilns, kilns/in-line raw mills and clinker coolers.

Response: We disagree with the commenter that the accuracy of a COMS meeting the ASTM 

D6216-07 and Performance Specification 1 requirements is at issue in this decision. A COMS so 

verified will reproduce opacity measurements satisfactorily (e.g., within 0.2 percent opacity) for 

levels of 3 percent and higher. The concern about monitoring the operation of a fabric filter 

control device is the need to discern between very small changes in opacity that are already at 

very low levels that would indicate a leak that may indicate a compliance problem. Such leaks 

will produce changes in opacity of less than 0.1 percent out of an average opacity of 0.5 to 1 

percent. These are values that would be comparable to the instrumental output noise in the data 

from COMS making the data insensitive to the leaks. PM CEMS and bag leak detectors are 

much more sensitive to these levels of change necessary to confirm compliance.

Comment: Several commenters (2845 and 2859) stated that the proposal does not remove the 

COMS requirement for kilns and kiln and/or inline raw mills for sources that would use BLDs. 

More important, EPA cannot remove COMS requirements that already exist in state operating 

permits for cement plants because it is expected that States will not be willing to reopen permits 

and other States would refuse based on previous and continuing reliance on COMS and Method 

9 as the primary performance tools that are more proven than BLDs. The commenter argued that 

redundant BLDs and COMS are not wanted and are not needed. Due to these complexities and 

overlapping requirements, the plant operator should have the final decision as to the selection of 

the most appropriate monitoring option.

Response: We agree that this was an oversight in the proposed rule and we have corrected it in 

the final rule.

PM CEMS

Comment: Two commenters (2845 and 2859) said that EPA has not promulgated any

regulations requiring PM CEMS at any source category due to its inability to address 

fundamental technical and policy issues and must resolve these issues through formal rulemaking 

before requiring PM CEMS at any cement plants. Furthermore EPA has not performed a 

legitimate technical analysis of emissions variability and compliance determination uncertainty

to allow the use of PM CEMS for determining continuous compliance with a PM limit at cement 

plants.

The use of PM CEMS in Europe and other countries does not constitute a valid basis for 

application of PM CEMS at cement plants in the United States. Light scattering, light 
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transmission, and extractive beta attenuation instruments are all inferential measurement devices 

and a correlation must be established to relate the device output to the actual PM concentration, 

then the accuracy and bias of the reference test and the uncertainty of the statistical correlation, 

as well as the stability of the correlation must be considered. Under the German TUV and the 

European monitoring standard (EN 14181) these uncertainties are considered; emissions are not 

considered to exceed the allowable limit until the lower bound of the confidence interval and/or 

tolerance interval exceeds the emission limit; emission standards may contain different averaging 

periods requiring different levels of conformance; and when a problem is encountered, the 

emphasis is on resolving the emission problem rather than direct enforcement and collection of 

financial penalties. All of these considerations place the European monitoring program in an 

entirely different regulatory context than the proposed PM monitoring requirements.

Response: We reject the commenters’ assertions that PM CEMS have not been required via 

rulemaking because of unresolved fundamental technical or policy issues. Concerns about PM 

CEMS were identified and addressed prior to the January 2004 publication of Performance 

Specification 11 and Quality Assurance Procedure 2 for PM CEMS (69 FR 1786, January 12, 

2004). As mentioned in that rule’s preamble, “...we believe that the PM CEMS field 

demonstrations completed to date encompass a range of operating conditions and emission 

characteristics...” including those exhibited by sources such as cement kilns. Moreover, we 

disagree with the assertion that our analysis of PM emissions variability is not legitimate, 

yielding an overly-stringent PM emissions limit. The PM limit is based on our analysis of PM

emissions from test data, adjusted from an hourly to a 30-day averaging period and further 

adjusted for variability. As mentioned in the preamble to the Credible Evidence Rule (62 FR 

8314, February 24, 1997), we have addressed and continue to address concerns about perceived 

“...limited number and distribution of test runs and the inherent variability in levels of 

emissions...” by a number of approaches, including changing emissions averaging periods.

Certainly, lengthening the averaging period beyond the duration associated with conducting a 

performance test (typically three hours) to 30 days without changing the value of the emissions 

limit does not increase stringency of an emissions limit. As mentioned in the description of the 

Salo and Pederson memoranda, “...(t)he effect of the change from a 3-hour averaging time to a 

30-day averaging time is to make the standard more lenient...”3 Further, a statistically-based 

adjustment to account for emissions variability, and which, in this case, increases the numerical 

value of the standard (and its longer averaging period) by fifty percent, does not make the 

standard more stringent.

Comment: Two commenters (2845 and 2859) had the following comments concerning technical 

issues associated with application of PM CEMS.

 EPA has not addressed nor resolved the primary technical issues limiting the effective 

application of PM CEMS at cement plants including:

– inability to generate a sufficiently wide range of PM concentrations to establish an 

acceptable correlation (i.e., calibration),

 

3

See Section 4.1.2.1 of the Credible Evidence Rule Response to Comment Document, available at 

<http://www.epa.gov/ttncaaa1/t1/fr_notices/certcfin.pdf>.
165

– accuracy and precision limitations of reference method at PM levels necessary to 

generate valid correlation, and

– subsequent changes in effluent matrix and/or PM (i.e., particle size distribution, 

refractive index, particle density, etc.) that influence the stability of the correlation 

and hence, the relationship between the output of the inferential measurement device 

relative to actual PM concentration.

 Valid PM CEMS correlations cannot be established for PM CEMS at cement plants due 

to limitations of process operation and control equipment in conjunction with the 

proposed emission limitation.

 The requirements in Appendix A, PS-11 for the PM CEMS correlation and in Appendix 

F, Procedure 2 do not provide a sufficiently reliable means to determine compliance with 

emission limitations.

Response: We have not identified problems cited by the commenters at existing installations.

PS-11 establishes the acceptable range for the concentrations for the correlation. This range is 

site specific. 

The acceptable accuracy and precision is specified in PS-11 by statistical criteria. If the reference 

method accuracy and precision is poor, a poor correlation would result and the statistical criteria 

limits would not be met. PS-11 strongly suggests the use of paired trains to insure that accuracy

and precision is obtained. 

Section 2.4 of PS-11 stresses the importance of planning for subsequent changes in effluent 

matrix and/or PM that might influence the correlation and describes the process required to 

enhance the probability of obtaining a successful correlation and the selection of the most 

appropriate CEMS for the installation. 

We note that PS-11 has several features to address correlation issues due to any limitations of 

process operation and control equipment. PS-11 provides for the addition of a zero point. For 

example, if control equipment operations cannot be varied adequately to achieve higher PM 

concentrations resulting in a cluster of data points at a very low level, making it difficult to 

achieve PS-11 criteria, an artificial data point may be selected at zero that allows the correlation 

curve to be developed, meeting correlation criteria.

PS-11 provides the steps in obtaining a reliable successful correlation with reference methods, 

thereby insuring compliance data that is sufficient to determine compliance with PM emission 

limits. Procedure 2 describes the required audits to insure that subsequent measurements are 

stable and within acceptable limits, thereby insuring reliable compliance data.

Comment: Two commenters (2845 and 2859) had the following comments concerning PS-11 

and Procedure 2.The requirements at §63.1349 for PM CEMS are incomplete and ambiguous 

and EPA has failed to specify important QA frequencies and other information relevant to the 

implementation of PM CEMS in accordance with PS-11 and Procedure 2. The proposed Subpart 

LLL revisions fail to address critical elements including the following sections of PS-11 and 

Procedure 2:
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 PS-11 3.20, species reference method as method defined in applicable regulations

(Method 5 with 250oF filtration temperature) but this is inadequate for low concentrations 

where Method 5I should be used, and is inapplicable to sources with PM that condenses 

between the stack temperature (mill on and mill off, if applicable) and 250oF where 

Method 17 should be used or ASTM D 6831.

 PS-11, 6.2 You must ensure that the averaging time, the number of measurements in an 

average, the minimum data availability, and the averaging period for your CEMS 

conform to those specified in the applicable regulation - but none are specified.

 When using PS-11, 6.5 Your CEMS must sample the stack effluent such that the 

averaging time, the number of measurements in an average, the minimum sampling time, 

and the averaging procedure for reporting and determining compliance conform to those 

specified in the applicable regulation - but none are specified.

 Procedure 2, 10.3 You must conduct an response correlation audit (RCA) and an relative 

response audit (RRA) at the frequency specified in the applicable regulation... but none 

are specified.

 Procedure 2, 10.3, You must perform an RRA at the frequency specified in the applicable 

regulation... but none is specified.

 When using Procedure 2, 10.3(7) You must perform an RCA at the frequency specified in 

the applicable regulation... but none is specified.

 When using Procedure 2, 10.9 You must report the accuracy results for your PM CEMS 

at the frequency specified in the applicable regulation... but none is specified.

Response: We recognize that PS-11 does not specify a reference method; we have revised the 

final rule to specify Method 5 or Method 5I (40 CFR 60, appendix A) as the reference method.

Facilities with issues in application of these reference methods, may petition the Administrator 

for alternatives or modifications under §60.8(b) or §63.7(f). The averaging times and data 

reduction specifications have been added to §§60.63(c) and 63.1350(b) of the rule. There is no 

specific data availability requirements, §§60.63(g) and 63.1348(b) require that monitoring be 

conducted at all times the affected source is operating except for periods of monitoring system 

malfunctions, repairs, or quality assurance/quality control activities. The language of the final 

rule has been revised to specify the frequency of the Relative Response Audits (annually) and the 

Response Correlation Audits (every three years), for specifics, see §§60.63(c) (2) and 

63.1350(b)(2). Absolute Correlation Audits are required by Procedure 2 on a quarterly basis.

Comment: Two commenters (2845 and 2859) said that the monitoring of PM emission 

concentrations downstream of wet scrubbers is not possible at cement plants due to the presence 

of water droplets and, during scrubber upsets, gypsum slugs. Heated extractive systems (either 

Beta gage or light scattering) are used at monitoring locations downstream of wet scrubbers at 

electric utilities. However, none of these devices can operate reliably in the presence of gypsum 

spray or very large particles. During malfunctions, upsets of the PM APCD, or during period of 

bypass, the wet scrubber will collect a large portion of the PM so that monitoring upstream of the 

wet scrubber may overstate actual PM emissions.

Response: We agree that PM CEMS would not work some of in these situations. However, the 

types of wet scrubbers that would be used for acid gas control are typically spray towers, which 
167

are not effective in controlling PM. Therefore, in these situations the source could elect to 

monitor for PM upstream of the wet scrubber without significantly affecting the PM 

measurements during these malfunction situations. In cases where this is not feasible, the source 

can apply for an alternative monitoring on a source specific basis.

Format of PM limit

Comment: Two commenters (2845 and 2859) stated that in the current rulemaking, EPA 

proposed an alternate PM MACT standard for sources that combine kiln and cooler exhaust 

streams to a single stack. The commenter agreed that an alternate PM MACT standard is 

required for sources that combine exhaust streams. However, the commenter argued that EPA 

failed to recognize all potential exhaust streams and has overly complicated the formula to 

account for the various exhaust gases. These commenters recommended that the PM standard 

should be based on units of pounds PM per ton of dry feed. This eliminates the need for a typical

feed:clinker conversion factor and have also recommended that EPA revise the PM MACT 

standards for existing and new sources to be more in line with the values derived by Commenter 

2845. Using the values of 0.092 lb/t of dry feed and 0.062 lb/t of dry feed for existing and new 

sources, respectively and EPA’s assumption of a standardized kiln flow rate of 54,000 dscf/t of 

feed, the applicable grain loading rate for each case would be 0.012 gram per dry standard cubic 

feet (gr/dscf) for existing sources and 0.008 gr/dscf for new sources. Lastly, it is not necessary to 

measure the volumetric rate from each exhaust stream separately. If two or more streams are 

combined into a single exhaust point, the measurable volumetric flow rates will already be 

added. A simplified formula can be found as part of the comments for Commenter 2859.

Response: As we noted at proposal, some kilns combine the clinker cooler gas with the kiln 

exhaust and send the combined emissions to a single control device. There are significant energy

savings (and attendant greenhouse gas emission reductions) associated with this practice, since 

heat can be extracted from the clinker cooler exhaust. However, there need to be different 

conversion factors from concentration to mass per unit clinker in these cases to allow for the 

increased gas flow, which result in a different PM emissions limit. We proposed adjustment 

factors that would account for these differences and create a site specific PM emission limit of 

this situation. See 74 FR 21155-56 and 2184. We received no comments on these factors and are 

thus adopting them as proposed, except that the factors have been changed to account for 

changes n the underlying kiln and clinker cooler emissions limits.

A site-specific compliance method can be requested for situations where additional sources of 

particulate are included in the same duct system leading to one stack.

See the preamble discussion under format of the normalized standards in the NESHAP and the 

NSPS, for more information on EPA’s decision regarding format of the standard.

Comment: One commenter (2844) requested that sources be given the option of compliance 

with an equivalent grain loading figure that would be in the rule and the rule automatically

approve the current methods for converting feed to clinker. This should be done on a monthly

rather than daily basis. The commenter ask that there be an ongoing compliance demonstration 

(between stack tests) alternative based on retaining the use of COMS as the indicator of 

acceptable operating conditions.
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Response: See the preamble discussion under format of the normalized standards in the 

NESHAP and the NSPS, for more information on EPA’s decision regarding format of the 

standard.

We are removing all opacity standards for kilns and clinker coolers because these sources will be 

required to monitor compliance with the PM emissions limits by more accurate means. Although 

some commenters requested retention of opacity as a backup standard, and others as an 

alternative, none of these comments offered any convincing information or other justification for 

perpetuating a less reliable compliance methodology.

Clarifications and corrections

Comment: Several commenters (2845 and 2859) stated that EPA has several areas in their 

proposed regulatory language that must be revised. In particular, EPA has language requiring 

opacity monitoring for kilns and coolers that no longer have opacity standards. Also, EPA has 

mandated performance testing where CEMS are required. Performance testing is typically 

required for sources that must conduct stack testing periodically to demonstrate that compliance 

is maintained. If CEMS are mandated performance testing is not necessary when compliance is 

demonstrated on a continuous basis.

One commenter (2845) stated that the current language for §63.1343(b)(2) limits opacity from 

kilns to no greater than 20 percent and in §63.1343(a)(2) limits opacity from clinker coolers to 

no greater than 10 percent, but the preamble of the proposed rule states We are proposing to 

remove all opacity standards for kilns and clinker coolers because these sources will be required 

to monitor compliance with the PM emissions limits by more accurate means. The commenter 

suggested that EPA should remove the opacity limits from the rule text for sources 

demonstrating compliance with a BLDS, PMDS or PM CEMS unless opacity monitoring is used 

as an alternative to the proposed options for monitoring PM emissions. EPA should provide an 

option for sources to comply with an opacity limit of 10 percent for kilns and 5 percent for 

clinker coolers using a COMS in lieu of the requirements for a BLD, PMD, and/or PM CEMS.

One commenter (2845) stated that §63.1349(b)(1) should be updated to account for clinker 

coolers that use PM CEMS. The commenter suggested the following alternative language: 

§63.1349 (b)(1) .The owner or operator of a clinker cooler subject to limitations on PM 

emissions that is not equipped with a PM CEMS shall demonstrate initial compliance by 

conducting a performance test as specified in paragraphs (b)(1)(i) through (b)(1)(iii) of this 

section. The owner or operator shall determine the opacity of PM emissions exhibited during the 

period of the Method 5 (40 CFR 60, Appendix A–3) performance tests required by paragraph 

(b)(1)(i) of this section as required in paragraphs (b)(1)(v) through (vi) of this section, if the unit 

is not equipped with a BLDS, PMDS or PM CEMS.

One commenter (2845) stated that the opacity limits in §63.1349(b)(1), §63.1350(c), §63.1350(d)

need to be removed from the rule text for source demonstrating compliance with a BLDS, 

PMDS, or PM CEMS unless opacity monitoring is used as an alternative to the proposed options 

for monitoring PM emissions. Example language for each section is provided by the commenter.
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Response: We have corrected the rule to remove duplicative requirements related to opacity

monitoring for units that no longer have opacity standards and performance testing requirements 

for sources that are using CEMS. Regarding the comment that COMS be allowed as an 

alternative, EPA’s experience is that facilities can significantly exceed PM limits without 

exceeding opacity limits. In contrast, BLD systems are much more sensitive to the point they are 

considered to be CEMS. Similarly, we believe that PM CEMS are a superior technology as well.

However, we would be happy to review evidence supporting more advanced COMS systems.

Comment: One commenter (2859) stated that EPA has not specifically stated in the rulemaking 

what the averaging period for the PM MACT standard will be. EPA has specified that the 

averaging periods for mercury, THC, and HCl are 30-day rolling averages. EPA has proposed 

CEMS for compliance demonstration for each of these pollutants. For consistency purposes, 

EPA should designate that the PM MACT standard should also be a 30-day rolling average if a 

PM CEMS is used to demonstrate compliance. If sources choose to use BLDS or other approved 

compliance demonstration methods, then a performance test consisting of the average of three 

one-hour stack testing periods would be the appropriate compliance averaging period for the PM 

MACT standard.

One commenter (2845) stated that there is no reference in §63.1343(a) to the averaging period 

for the PM limit if PM CEMS are used. The commenter suggested that the last sentence of 

§63.1343(a) be changed to read, If using a CEM to determine compliance with the PM or HCl 

standards, these standards are based on a 30–day rolling average.

Response: We have corrected the rule to provide for a 30-day rolling average when using PM 

CEMS.

Comment: Two commenters (2845 and 2859) stated that EPA should clarify whether an ESP 

predictive model may be used in lieu of other PM monitoring approaches and what requirements 

would apply if this option is selected. No mention of an ESP predictive model is found in the 

performance testing or monitoring sections of the proposed rule. If EPA allows use of a 

predictive ESP model as an alternative to other monitoring, then the minimum parameters and 

technical criteria for determining the acceptability of the predictive model should be specified.

Response: We will consider source-specific requests to use an ESP predictive model

Comment: Two commenters (2845 and 2859) stated that it should be clarified that kiln/raw mill 

and cooler stack(s) that have installed BLD, PMD, or PM CEMS would not be subject to 

monthly 20-minute visible emissions test of each affected source in accordance with Method 22 

under §63.1350(a)(4)(i).

Response: We have corrected the rule to remove this duplicative requirement.

Comment: Two commenters (2845 and 2859) stated that EPA has not provided any technical 

basis for changing the duration of the Method 22 test in §63.1350(a)(4)(i) and that changing the 

duration from 1 minute to 20 minutes for numerous sources places an unnecessary burden on the 

plant operators. An increase in the duration of visible emissions from 1 minute to six minutes 

would be a more reasonable change and would be more consistent with the minimum 

observation period for Method 9 visible emission observations.
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Response: While we do not think this is an unreasonable requirement once per month, we have 

reduced the observation period in half to 10 minutes, which should be sufficient to observe any 

problems. There is no reason to be consistent with a Method 9 observation period, because the 

tests are different.

Comment: One commenter (2845) stated that Equations 3 and 4 apply a metric conversion 

factor to the emission rate. The commenter stated that the formula does not work in metric units, 

and suggested alternative wording for these equations that had the emission rate in only lb/ton.

Response: We have not been able to identify the problem raised by the commenter. The units in 

the equations are those that are commonly measured.

Comment: One commenter (2845) stated that §63.1349(b)(1)(vi) should either be removed or

updated to account for clinker coolers. The averaging period for sources using PM CEMS for 

compliance with the particulate matter standards should be based on a 30-day rolling average. 

The commenter noted that there is no need to conduct a separate performance test under raw mill 

on/off conditions when using a PM CEMS for measuring compliance as the PM CEMS will 

measure compliance and thus account for both conditions.

One commenter (2845) stated that §63.1350(a)(4)(v) indicates that visible emissions monitoring 

requirements do not apply to totally enclosed conveying system transfer points. However, 

§63.1349 does not currently indicate that initial performance testing is not required for totally 

enclosed conveying system transfer points. Section 63.1349 should be revised to clarify that 

initial performance testing is not required for totally enclosed sources. 

Response: We have corrected the rule to remove the inconsistencies identified by the 

commenter. We have also clarified the rule to specify a 30-day rolling average.

Comment: One commenter (2845) stated that §63.1350(a)(4)(vii) indicates that you must test 

visible emissions from each side, roof, and vent of the building. However, this is not included in 

the initial performance testing section. Section 63.1349 should be revised to be consistent with 

the wording in §63.1350(a)(4)(vii). Further, a 6 minute observation should be sufficient to 

demonstrate compliance with visible emissions standards. The 6 minute duration would also be 

consistent with the minimum observation time for a Method 9 data set (40 CFR 60 Appendix A, 

Method 9, Section 2.5 Data Reduction). The commenter provides example alternative language.

Response: We have corrected to the rule to include the performance testing requirements.

Regarding the length of the observation period, we have reduced the period to 10 minutes, which 

should be sufficient to observe any problems. There is no reason to be consistent with a Method 

9 observation period, because the tests are different.

Comment: One commenter (2845) stated that in regard to §63.1349(b)(2), the proposed rule 

should specify test requirements for sources with limited operation. An option would be to use 

language similar to that used in NSPS Subpart OOO (see 40 C.F.R. §60.675(c)(2)(ii): The 

duration of the Method 9 (40 C.F.R. Part 60, Appendix A–4) observations may be reduced to the 

duration the affected facility operates (but not less than 30 minutes) for baghouses that control 

storage bins or enclosed truck or railcar loading stations that operate for less than 1 hour at a 

time.).
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Response: The observation does not need to be consecutive, which we have clarified in the final 

rule to address this situation.

Comment: One commenter (2845) stated that the proposed requirement to conduct five 6-

minute Method 9 tests is unnecessary. No rationale was provided for the increase in the number 

of tests. 

Response: This test is only required when visible emissions are identified, which should be a 

limited occurrence. However, when it does occur, we think that conducting a valid Method 9 test 

would take at least 30 minutes.

Comment: One commenter (2845) stated that §63.1350(k) does not currently address PMDS. 

Multiple portland cement plants currently use PMDS for compliance with Subpart EEE, and 

language used in §63.1206(c)(9) (NESHAP Subpart EEE) provides PMDS requirements for 

Hazardous Waste Combustors that utilize PMDS to monitor compliance with PM standards 

which could be used as a template for inclusion in Subpart LLL.

Response: We will consider source-specific requests to use PMDS

Comment: One commenter (2845) stated that an exclusion installing, operating, and maintaining 

a BLDS for sources using a PM CEMS should be included in §63.1350(k). The commenter also 

noted that the rule only applies to sources with fabric filters, which is not a defined term. For 

clarification, the rule should specifically state that it does not apply to sources with gravel bed 

filters and ESPs.

Response: We have clarified that sources using a PM CEMS are not required to use a BLDS.

We have clarified in the final rule that fabric filters do not include gravel bed filters and ESPs.

Comment: One commenter (2845) suggested that EPA delete §63.1350(k)(1)(i) or develop 

design and performance specifications for manufacturers to certify their BLDS to meet the 

criteria required in this section.

Response: The proposed requirements have been used successfully in several other rules. EPA is 

developing a BLD performance specification that will be put in place when it is available.

Comment: One commenter (2845) stated that in §63.1350(k)(2), the phrase At a minimum you 

must retain records related to the site specific monitoring plan and information discussed in 

paragraphs (k)(2)(i) through (k)(2)(vi) of this section for a period of 2 years on-site and 3 years

off-site implies that off-site record storage is mandatory rather than optional. The commenter 

suggested that EPA should only specify the minimum period of time required for overall record 

retention and the minimum period of time required for onsite storage, leaving the option for 

offsite storage to the discretion of the owner/operator.

Response: We agree with the clarification suggested by the commenter and have added it to the 

rule.

Comment: One commenter (2845) stated that §63.1350(k)(4) references kilns and clinker 

coolers, but only the emission limits in §63.1343, which is for kilns. To be consistent with 
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§63.1350(p), the clinker cooler emission limit reference would need to be added. However, this 

paragraph is also a duplicate of §63.1350(p) introducing the PM CEM requirements and it would 

be more appropriate to delete it altogether to prevent confusion.

Response: We agree and have made the change suggested by the commenter.

Comment: One commenter (2845) stated that the reference to new or existing sources should be 

removed from §63.1350(o). This should apply to all sources; new, existing, or reconstructed.

Response: We agree with the clarification suggested by the commenter and have added it to the 

rule.

Comment: One commenter (2845) stated that opacity standards only apply to sources that elect 

to utilize a COM for PM compliance demonstration, therefore, correlations with opacity will no 

longer be needed and should be deleted from portions of §63.1357.

Response: We agree with the clarification suggested by the commenter and have added it to the 

rule.

Transmisometers

Comment: One commenter (2879) stated that the European cement industry has used 

transmisometers to report PM emissions for many years. The commenter stated that opacity 

readings underreport PM emissions, and provided emission test data using transmisometers. The 

commenter also noted that BLDS are not adequate to measure noncompliance, and 

recommended that EPA should adopt regulations similar to those established in Europe, the 

parent companies of most American cement companies, that require particulate emissions and 

associated metals emissions be determined using monthly averaged transmisometer readings. 

Response: We have clearly established the value of PM CEMS for this industry, and we believe 

PM CEMS are superior to BLDS for this industry. 

Advantages of opacity standards

Comment: One commenter (2786) stated that EPA should not eliminate opacity standards in the 

proposed rule. The commenter stated that there are benefits to having an opacity standard in 

conjunction with a particulate matter standard. Opacity measurements can be made by anyone 

who is trained to measure opacity, which can include members of the public and not just 

inspectors, and opacity measurements are a cheaper method of getting more frequent 

measurements.

Response: See response in preamble

Monovent compliance demonstration

Comment: One commenter (2888) requested that monovent kilns be allowed to continue 

compliance demonstration as outlined in the current PC MACT. The monovent design 

orientation does not provide a means for either BLD, a PM CEM or and opacity monitor.
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Response: The rule contains the necessary and appropriate monitoring requirements. Monovent 

sources can add a stack. Or, they can apply for alternative monitoring requirements on a sourcespecific basis.

Require PM CEMS and retain opacity monitors

Comment: One commenter (2898) stated that EPA should require PM CEMS and retain the 

opacity monitoring requirements. EPA is proposing installation and operation of a BLD system, 

along with stack testing using EPA Method 5 conducted at a frequency of five years for 

demonstrating compliance with the proposed PM emissions limit. As an alternative a PM CEMS 

that meets the requirements of PS–11 may be used, and EPA is proposing to eliminate the 

current requirement of using an opacity monitor. The proposed rule solicits comment on making 

the use of a PM CEMS a requirement. The commenter stated that EPA should both require 

CEMS and retain the use of opacity monitors.

EPA should abandon the BLD system requirement outlined in the proposed rule and mandate the 

use of PM CEMS instead. The agency previously concluded that PM CEMS is a superior 

monitoring technology that can be implemented at a reasonable price. EPA has found that BLD 

systems, standing alone, are inadequate to verify compliance and has also found that COMS 

operate as a useful check on PM emissions and proper operation of PM CEMS. 

Providing a superior level of compliance assurance is not the only benefit of PM CEMS. EPA 

has acknowledged that the assumptions to assure compliance are fewer and less conservative 

(direct measure of the standard is the top of the monitoring hierarchy), CEMS mean facilities 

need to monitor only one emissions parameter to assure compliance rather than multiple 

operating limits, often relevant to more than one standard, and that the cost of installing PM 

CEMS technology is reasonable. 

Response: See response in preamble.

HAP metals monitoring

Comment: One commenter (2638) stated that proven HAP metals monitoring methodology is 

now commercially available.

Response: We are aware that multi-metal CEMS have been tested and would support their use 

should they become readily available. However, at this time we do not have sufficient data to set 

individual metals standards for this source category, which would be necessary of we were to use 

multi-metals CEMS to demonstrate compliance. .In addition, we believe these systems are not 

sufficiently demonstrated for this source category to be the basis of compliance measurement

30-day rolling average compliance period for PM CEMS

Comment: One commenter (2859) recommended that EPA adopt a 30-day rolling average 

standard for sources that utilize PM CEMS. Sources that opt to use an alternative compliance 

demonstration methodology (stack testing) would demonstrate compliance by conforming to the 

relevant test method.
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Response: We agree with the clarification suggested by the commenter and have added it to the 

rule.

2.8.5 Impacts

Scrubber performance on PM control

Comment: One commenter (2900) provided stack test data for PM before and after a wet 

scrubber was installed. The data shows that the emissions would still exceed EPA requirements 

even after optimization of the scrubber through the last five to six years. The commenter stated 

that this scrubber will require some additional equipment or modification in its operation to 

achieve the EPA target and it remains uncertain if this is achievable. However, it can be reported 

that based on the current data, it would appear that the emissions were significantly reduced after 

installation of the wet scrubber.

Response: Most if not all cement manufacturers are using fabric filters or electrostatic 

precipitators in order to reduce PM emissions. We believe that in order to comply with the final 

limit for PM for both existing and new sources, fabric filters using membrane bags will be 

required. 

Benefits of PM2.5 reductions

Comment: One commenter (2916) stated that EPA should not use a no-threshold model for 

estimating the benefits of reducing PM2.5 emissions. EPA’s proposal to adopt a no-threshold 

model as a part of this rulemaking will obscure the greater uncertainty associated with calculated 

premature mortality at PM concentration levels down to background (or even below 

background). The treatment of uncertainty is one of the key issues associated with conducting 

benefit/cost analysis. A number of National Research Council reports have found that the proper 

characterization of uncertainty is essential. The commenter recommended that if EPA adopts a 

no-threshold model to develop estimates of mortality, it should present its premature mortality

estimates within concentration ranges and provide a complete discussion of the uncertainty in the 

estimates within each concentration range. EPA should discuss the plausibility and the 

uncertainties of the estimates within each concentration category in the body of its analysis and 

in its Executive Summary.

Several commenters (2845 and 2849) stated that for the RIA, EPA abandoned their traditional 

assumption that there may be a threshold in the concentration-response function relating 

exposure to PM2.5 and premature mortality and EPA should not change its approach on this 

important issue until such a shift has been recommended by Clean Air Scientific Advisory

Committee (CASAC) and adopted as final policy. If EPA were to assume a threshold at 10 ug/m3

as has been done in recent RIAs, estimated benefits would be some 20–40 percent lower than 

what the agency now calculates in the Portland Cement NESHAP RIA.

One commenter (2845) identified the following as serious shortcomings in EPA’s estimate of 

benefits that include the following:

 EPA has overstated the benefits of PM2.5 reductions by removing the assumption of a 

threshold in the dose-response relationship for premature mortality. This is a significant 
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methodological that deserves a discussion in the context of the ongoing review of the PM 

NAAQS, rather than in the context of a NESHAP for a single industry that is not even 

focused on PM2.5. This commenter is concerned that a premature decision on this issue as 

a part of this rulemaking will serve as a precedent for decisions in the PM NAAQS 

review.

 EPA’s use of a no-threshold model in this rulemaking will obscure the greater uncertainty 

associated with calculated premature mortality at PM concentration levels down to or 

below background. The treatment of uncertainty is one of the key issues associated with 

conducting a benefit/cost analysis. 

 In setting the NAAQS, EPA has recognized that there is greater uncertainty in the 

relationship between the risk of premature mortality and PM exposure at low 

concentrations. In the quantitative risk assessment in the 2006 final rule for the PM 

NAAQS, EPA presented several estimates based on different cut points intended as 

surrogates for alternative assumed population thresholds. In reviewing the Staff Paper 

and risk assessment, the CASAC panel commented that for the purpose of estimating 

public health effects, it favored the primary use of an assumed threshold of 10 ug/m3.

 Several factors can contribute to the uncertainty in estimating premature mortality at low 

PM concentrations. EPA has generally assumed either a proportional or quadratic 

rollback to represent the effectiveness of control strategies designed to meet the NAAQS, 

but in areas with PM levels below 10 ug/m3 there may be little or no change in air 

quality. If EPA adopts a no-threshold model, it should address these several factors in its 

discussion of the uncertainties in the premature mortality estimates. Commenter 2845 

stated that this discussion on whether to adopt a no-threshold model and the uncertainties 

associated with EPA’s premature mortality estimates should include a separate discussion 

for those estimates associated with exposure at lower ambient concentration levels.

 Commenter 2845 noted that EPA had adopted a no-threshold model in the development 

of PM benefits for the Tier 2 rule and on-highway heavy duty diesel engine rules in 1999 

and 2001. However, the 2002 National Research Council report estimating the Public 

Health Benefits of Proposed Air Regulations suggested that EPA’s approach in these two 

rules failed to provide information on the plausibility of estimates at different PM 

concentration levels. The committee suggested that alternative approaches that reflected 

expert judgment on the plausibility of thresholds would have represented an improvement 

in EPA’s primary analysis. EPA has recently carried out a multi-year effort using expert 

elicitation to assess the relationship between exposures to fine PM and the incidence of 

mortality. If EPA adopts a no-threshold model, EPA should incorporate the results of this 

study in presenting its PM benefits analysis for different concentration levels.

Response: The weight of scientific evidence strongly supports modeling PM-related mortality

and morbidity by using concentration-response functions that do not incorporate an assumed 

threshold. In 1999, the SAB Advisory Council on Clean Air Compliance Analysis (ACCACA) 

concluded that there was currently no scientific basis for selecting any specific threshold (EPASAB-Council-ADV-99-012). In 2004, the Health and Environmental Effect subcommittee of 

ACCACA concluded, “it is reasonable for EPA to assume a no threshold model down to, at least, 

the low end of the concentrations reported in the studies” (EPA-SAB-COUNCIL-ADV-04-002). 

In 2005, CASAC indicated that “[t]he available epidemiological database on daily mortality and 
176

morbidity does not establish either the presence or absence of threshold concentrations for 

adverse health effects” (EPA-SAB-CASAC-05-007). 

In 2006, EPA conducted an expert elicitation on the relationship between PM2.5 exposure and 

premature mortality. Eleven of the twelve experts in this study did not specify a threshold in their 

concentration-response function, whereas one expert specified a 50% probability of no-threshold, 

40% probability of a threshold below 5 μg/m3, and 10% probability of a threshold between 5 and 

10 μg/m3. EPA presents these expert-derived results in the RIA independently of whether 

thresholds are included in the core benefits results or not.

In 2009, the final Integrated Science Assessment for Particulate Matter indicated that “[o]verall, 

the studies evaluated further support the use of a no-threshold log-linear model...” (U.S. EPA, 

2009). In 2010, the Health Effects Subcommittee of the Science Advisory Board “fully supports 

EPA’s decision to use a no-threshold model to estimate mortality reductions. This decision is 

supported by the data, which are quite consistent in showing effects down to the lowest measured 

levels. Analyses of cohorts using data from more recent years, during which time PM 

concentrations have fallen, continue to report strong associations with mortality. Therefore, there 

is no evidence to support a truncation of the CRF ” (EPA-SAB-COUNCIL- -10-001).

Our approach to estimating PM-related health impacts is consistent with the key findings in these 

reports. In addition, our approach is consistent with the on-going PM NAAQS review.

The commenter incorrectly suggests that using a no-threshold concentration-response function 

would erroneously model benefits down to, or below, background. Instead, we applied benefit 

per ton estimates that were calculated using previously generated air quality scenarios projecting 

air quality changes well above background levels. For the final analysis, we estimated benefits 

on the basis of modeled air quality changes from CAMx, where we again considered air quality

changes well above background levels.

In conjunction with the commenter’s concern, and consistent with recent scientific advice, we 

have replaced the previous threshold sensitivity analysis with a new “lowest measured level” 

(LML) assessment. While an LML assessment provides some insight into the level of uncertainty 

in the estimated PM mortality benefits, EPA does not view the LML as a threshold and continues 

to quantify the PM-related mortality impacts using the full range of modeled air quality

concentrations. The results of this analysis are provided in Section 6 of the RIA.

2.8.6 Other

PM as surrogate for HAP metals

Comment: Several commenters (2832 and 2859) stated that the use of PM as a surrogate for 

HAP metals is an important issue in this proposal; however, EPA has failed to explain its 

selection of using PM as a surrogate for HAP metals and how that approach was applied 

specifically to the data in this administrative record. EPA is required to specifically detail how 

this approach was used and what other approaches were taken and rejected and why as part of 

the Preamble to the proposal.
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Response: Use of PM as a surrogate for non-volatile HAP metals – in this very industry – has 

already been upheld. See National Lime II, 233 F. 3d at 639.

Comment: One commenter (2638) stated that it is no longer appropriate to use PM as a 

surrogate for HAP metals. The commenter provided citations of studies, and summarized the 

main points supporting this statement. The commenter further argued that the courts have 

questioned whether the use of PM as a surrogate for HAP metals is scientifically reasonable, that 

HAP metals are not invariably present in cement kiln PM, PM control technology does not 

indiscriminately capture HAP metals along with other particulates, and PM control is not the 

only means by which facilities achieve reductions in HAP metal emissions.

The commenter stated that direct measurement of HAP metals is essential for the EPA to comply 

with the spirit and intent of the Clean Air Act, and direct measurement of HAP metals is required 

to evaluate residual risks.

Response: The EPA disagrees with the commenter. We continue to believe this is an 

appropriate surrogate. Particulate matter controls do in fact capture HAP metals along with other 

particulate matter, with the exception of mercury, for which we have set separate emission limits 

under this rule making. We have shown that particulate matter is an appropriate surrogate for 

non-volatile metal HAP in numerous previous rulemakings, including the NESHAPs for Iron 

and Steel Foundries (69FR 21912, April 22, 2004) and the NESHAP for Taconite Iron Ore 

Processing (68 FR 61885, October 30, 2003).

NESHAP and NSPS PM limits

Comment: Several commenters (2845 and 2874) agreed that if EPA is proposing PM limits 

under both the NESHAP and NSPS, the source should comply with the most stringent emission 

limit. The commenters suggested that EPA explicitly exempt the source from complying with all 

associated requirements (monitoring, recordkeeping, and reporting) relating to the less stringent 

limit, not just from that limit itself. 

Response: The standards are now identical. 

Volatilized metal HAP emissions

Comment: One commenter (2898) stated that under the high temperature conditions of the 

cement kiln non-volatile metal HAP emissions could occur outside of the particulate form. 

Therefore, EPA should assess the emission levels and associated public health threats remaining 

after successful implementation of the proposed standard. 

Response: EPA already has a mechanism in place for conducting an assessment of public health 

threats remaining after implementation of MACT. The Risk and Technology Review (RTR) is a 

combined effort to evaluate both risk and technology as required by the Clean Air Act (CAA) 

after the application of maximum achievable control technology (MACT) standards. Section 

112(f) of the CAA requires EPA to complete a Report to Congress that includes a discussion of 

methods the EPA would use to evaluate the risks remaining after the application of MACT 

standards. These are known as residual risks. Section 112(f)(2) directs EPA to conduct risk 

assessments on each source category subject to MACT standards, and to determine if additional 
178

standards are needed to reduce residual risks. Section 112(d)(6) of the CAA requires EPA to 

review and revise the MACT standards, as necessary (but no less often than every 8 years), 

taking into account developments in practices, processes and control technologies.

Thallium

Comment: One commenter (2144) stated that thallium metal (Tl) and its compounds are highly 

toxic materials and are emitted from certain cement plant on the finest dust particles emanating 

from the stacks. The commenter stated that concentrations in certain cement filter dusts can build 

up to levels greater than 1 percent (10,000 ppm) and that proper regulation of PM coupled with 

the required mercury reduction will concurrently address such Tl concentration buildup and 

emissions. In the long run, consider regulation of Tl as a HAP consistent with present European 

practice.

Response: Thallium is not currently listed as a hazardous air pollutant (HAP) under Section 

112(b) of the CAA. As such, EPA does not have the authority to regulate emissions of thallium 

under the provisions for establishing MACT standards.

2.9 Compliance Dates

Arbitrary compliance dates

Comment: Many commenters (2832, 2845, 2859, 2863, 2864, 2874, 2890, 2914, and 3193) 

stated that EPA should follow the intent of the CAA sections 111 and 112 which established the 

requirement that new and existing sources recognized in the proposed rule use the published date 

of May 06, 2009, as the new source trigger date for mercury, HCl, and THC emission standards 

instead of the proposed retroactive date of December 2005 when the amendments for mercury, 

THC, and HCl were first proposed. The commenters stated that despite the direct 

acknowledgements in the proposed rule, EPA arbitrarily decided to apply a proposal date for 

mercury, THC and HCl that reaches back and applies new source standards to any plant 

constructed since December of 2005 and admitted that the 2005 proposal did state EPA’s desire 

to establish floors for THC, HCl and mercury. According to the commenters, this is irrelevant 

because sources constructed in the past four years cannot have reasonably anticipated their need 

to comply with the 2009 proposed floors based on the 2005 proposed rulemaking. The 2005 

rulemaking resulted in a final rule with floors for THC and mercury, and no HCl floor (due to its 

classification as a threshold pollutant), which are significantly different than the 2009 proposal 

and the 2005 proposal did not reference a desire to establish a floor for PM, nor one as stringent 

as that set forth in the current proposal.

Response: As explained in the preamble, EPA agrees with these comments and has adopted a 

May 6, 2009, compliance date for determining when sources come into existence for purposes of 

determining which sources are subject to new source MACT.

Reduced compliance period

Comment: One commenter (2891) disagreed with EPA’s decision to grant 3 years from the date 

of the rulemaking for existing sources to come into compliance. Given the serious impacts of 
179

these emissions on public health and the fact that the industry has had ample warning of these 

standards, a shorter compliance timetable is reasonable. The commenter supported a compliance 

date of no more than 2 years.

The commenter agrees that new sources should comply upon commencement of operation. The 

commenter agreed with EPA’s selection of December 5, 2005, as the proper date for determining 

when a source is deemed to be new for THC, mercury and HCL. The commenter stated that the 

determination for PM ought to be March 24, 1998, which is the date that EPA first proposed PM

restrictions on this sector, and is therefore a date consistent with the language and intention of 

the Act.

Response: The commenters do not address EPA’s analysis at proposal indicating that the phrase 

“first proposes” in section 112 (a)(4) is ambiguous, nor other provisions (e.g. sections 112 (i)(2)) 

indicating that the phrase is ambiguous. Nor did the commenters address the similar language in 

section 111 (a)(2) for NSPS, which has never been interpreted as stretching back in time for 

decades to match an initial proposal date. For the reasons stated in the preamble to the final rule, 

EPA believes the proposed date of these amendments is a proper compliance date for purposes of 

determining the applicable date for new, reconstructed, or modified sources. 

Comment: One commenter (2898) recommended that EPA consider a faster timeline for 

existing sources implementation and to finalize its proposal on compliance dates for new 

sources. EPA has proposed to use the date of December 5, 2005, as the date for determining if a 

source is existing or new for the purposes of the mercury, THC, and HCl standards, and has 

proposed May 6, 2009, as the relevant date for PM standards. The commenter supported EPA’s 

proposed dates as a reasonable interpretation of the statute’s definition of a new source as a 

stationary source the construction or reconstruction of which is commenced after the 

Administrator first proposes regulations under this section establishing an emissions standard 

applicable to such source. 42 U.S.C. §7412(a)(4). We agree that the statutory definition should 

be read to apply pollutant-by-pollutant and to the rulemaking record under which a standard is 

developed to avoid subjecting sources in existence for 10 years to the new standards which they

could not have anticipated at the time. This is consistent with the statute’s structure requiring 

more stringent standards for new sources.

Response: As explained in the preamble, EPA has adopted a May 6, 2009, compliance date for 

determining when sources come into existence for purposes of determining which sources are 

subject to new source MACT. For the reasons stated in the preamble to the final rule, EPA 

believes the proposed date of these amendments is a proper compliance date for purposes of 

determining the applicable date for new, reconstructed, or modified sources.

For existing sources we proposed a compliance date of 3 years after the promulgation of the new 

emission limits for mercury, THC, PM, and HCl to take effect. This is the maximum period 

allowed by law (subject to a one-year extension determined on an individualized basis to install 

technology). See section 112(i)(3)(A) and (B). We continue to believe a 3 year compliance 

period is justified because most facilities will have to install emissions control devices (and in 

some cases multiple devices) to comply with the proposed emissions limits. Therefore, we have 

retained a 3 year compliance data in this final rule.
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For new sources, the compliance date will be the effective date of this final rule or startup,

whichever is later. Because this is a major rule as defined by the Congressional Review Act, the 

effective date of the rule is 60 days after publication of the Federal Register.

In determining the proposal date that determines if a source is existing or new, we have decided 

to select the proposal date of these final amendments, which is May 6, 2009, for all the 

standards.

At proposal, we considered three possible dates, including March 24, 1998; December 5, 2005; 

and the proposal date of these final amendments, which was May 6, 2009. As we noted at 

proposal, Section 112 (a)(4) of the Act states that a new source is a stationary source if “the 

construction or reconstruction of which is commenced after the Administrator first proposes 

regulations under this section establishing an emissions standard applicable to such source.”

“First proposes” could refer to the date EPA first proposes standards for the source category as a 

whole, or could refer to the date the agency first proposes standards under a particular 

rulemaking record or first proposes the particular standards at issue. The definition is also 

ambiguous with regard to whether it refers to a standard for the source as a whole, or to a HAPspecific standard (so that there could be different new source standards for different HAP which 

are regulated at different times). At proposal we chose the date of December 5, 2005, as the 

proposal date that determines if a source is new or existing for the mercury, HCl, and THC, and 

the May 6, 2009, date for PM.

After consideration of comments on the selection of the date for mercury, THC, and HCl, we 

believe that the May 6, 2009, date for all pollutants is more in keeping with the evident intent of 

Section 112 (a)(4) that source should have sufficient notice that new source controls 

requirements can be considered in the initial design. We accept commenters’ argument that 

sources coming into existence between the proposed date of the 2006 standards and the May 6, 

2009, proposal date of these amendments would have no reasonable means of ascertaining the 

standards’ final content and so lacked notice of what controls and strategies to adopt. Since this 

is antithetical to the policy underlying new source standards, EPA is adopting May 6, 2009, as 

the date which determines if a source is existing or new.

We note that there are currently sources subject to new source limits for mercury and THC 

contained in the December 20, 2006, rule. However, the mercury the new source standards in 

this final rule are significantly different than the limits in the December 20, 2006, rule, and we do 

not see how the affected sources could have anticipated this change prior to proposal of these 

amendments. Accordingly, we have selected a date that allows these facilities to design and 

install the required control equipment.

See the preamble discussion under compliance dates for more information on EPA’s decision.

2.10 Startup, Shutdown, Malfunction (SSM)

Limit emissions during periods of SSM

Comment: Several commenters (2155, 2891, 2895, 2898, and 2911) supported emissions 

standards for startup, shutdown, and malfunction equal to normal operating conditions. 
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Commenter 2155 stated that if less stringent standards are considered, they should be for only a 

very short time period around startup and shutdown. To keep malfunctions at a minimum, we 

would not recommend less stringent standards for such occurrences, lest they become the norm. 

Commenter 2898 requested EPA to clarify if it intends to remove the exemption for all sources at 

cement facilities and stated that EPA may deviate from the MACT floor standards only in very

limited circumstances. EPA may establish work practice or operational standards, different than 

the established MACT floor standards, only if it is not feasible to prescribe or enforce an 

emission standard on the basis of either a design or source-specific basis. 

Response: EPA is adopting separate standards for startup and shutdown. These standards are 

explained in the preamble to the final rule. As explained in the preamble, the standards for these 

operating modes is expressed on a concentration basis (not normalized to production) and use 

different averaging periods than the main standards. Malfunctions may in fact occur, and when 

malfunctions result in emission that cause the standard to be exceeded, they can contribute to 

violations, although sources have a n affirmative defense to civil penalties if they are able to 

establish the affirmative defense set out in 63.1344 of the final rule.. During malfunctions, 

sources are also obligated to limit hazardous emissions to the extent possible, following good 

engineering practices protective of safety and the environment.

MACT emission standards for periods of SSM unreasonable

Comment: Many commenters (2832, 2841, 2844, 2845, 2859, 2863, 2887, 2890, 2901, 2916, 

2929, and 3218) opposed setting MACT emissions standards for periods of SSM. The 

commenters opposed setting MACT emissions standards or limits that fail to reflect differing 

processes and process equipment conditions, including air pollution control and monitoring 

equipment, during each of these SSM timeframes. It is physically impracticable, if not 

impossible, for the process units in question to shut down immediately in the event of a 

malfunction. These emissions conditions during SSM are not the same as the conditions during 

regular or routine operations. Commenter 2887 provided examples of opacity data collected 

during SSM events. Commenter 2901 stated that EPA’s proposed requirement that facilities meet 

steady-state standards during SSM events is not lawful, citing decisions previous to the Court’s 

decision in Sierra Club v. EPA, 551 F.3d 1019 (DC. Cir 2008) that held that technology-based 

standards must contain exemptions or less stringent standards during SSM periods. The 

commenter stated that because all pollution control technologies will occasionally malfunction 

and take time to get to their steady-state conditions, achievable technology-based standards must 

contain provisions excusing noncompliance or making compliance easier during such 

unavoidable events. 

Commenter 2916 stated that EPA knows that emissions during periods of SSM are likely to be 

different than emissions during normal operations but the Agency ignores these facts and, 

instead, simply points to an absence of emissions data from SSM periods as a reason to propose 

that standards based on data from periods of normal operation are appropriate. The absence of 

emissions data creates a duty for the Agency to gather the data needed to set specific standards 

for SSM or, if developing such information is not technically feasible, setting work practice 

standards for SSM periods.
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One commenter (2844) stated that if EPA applies the proposed emission limits at the time of 

SSM events, then such events constitute reasonably foreseeable operating conditions, and 

certainly the range of such events, including their worst impacts on emissions achievements, 

needs to be taken into account when estimating the floor units’ emissions variability achieved in 

practice.

Response: As discussed in the preamble, EPA has taken into account cement kilns’ operating 

properties during startup and shutdown periods and has established different standards for those 

periods where appropriate. Therefore, commenters concerns regarding startup and shutdown 

periods have been considered and addressed in the final rule. For the reasons explained in the 

preamble to the final rule, EPA is not setting separate standards for malfunctions and during a 

malfunction, the otherwise applicable standard applies. However, as explained in the preamble to 

the final rule, in the event that a source fails to comply with the applicable CAA section 112(d) 

standards as a result of a malfunction event, EPA would, of course, determine an appropriate 

response based on, among other things, the good faith efforts of the source to minimize 

emissions during malfunction periods, including preventative and corrective actions, as well as 

root cause analyses to ascertain and rectify excess emissions. EPA would also consider whether 

the source's failure to comply with the CAA section 112(d) standard was, in fact, “sudden, 

infrequent, not reasonably preventable” and was not instead “caused in part by poor maintenance 

or careless operation.” 40 C.F.R. § 63.2 (definition of malfunction). See, Weyerhaeuser v Costle, 

590 F.2d 1011, 1058 (D.C. Cir. 1978)( “ In the nature of things, no general limit, individual 

permit, or even any upset provision can anticipate all upset situations. After a certain point, the 

transgression of regulatory limits caused by "uncontrollable acts of third parties," such as strikes, 

sabotage, operator intoxication or insanity, and a variety of other eventualities, must be a matter 

for the administrative exercise of case-by-case enforcement discretion, not for specification in 

advance by regulation.”) 

As also discussed in the preamble, in light of comments raising concerns with EPA’s proposed 

approach to malfunctions, the final rule includes an affirmative defense to civil penalties for 

exceedances of emission limits that occur during malfunctions. See 40 CFR 63.1341 (defining 

“affirmative defense” to mean, in the context of an enforcement proceeding, a response or 

defense put forward by a defendant, regarding which the defendant has the burden of proof, and 

the merits of which are independently and objectively evaluated in a judicial or administrative 

proceeding.). This approach is not inconsistent with the Pre-Sierra Club cases, Portland Cement 

Ass’n v. Ruckelshaus, 486 F.2d 375 (D.C. Cir. 1973) and Essex Chemical Corp. v. Ruckelshaus, 

486 F.2d 427 (D.C. Cir. 1973), cited by one commenter. Although the relevance of those cases is 

not clear in light of intervening caselaw, EPA’s overall approach to malfunction events in this 

rule is consistent with the approach set forth in EPA’s 1972 proposed rules that were cited 

favorably in those decisions in that both “impart a construction of "reasonableness" to the 

standards as a whole and adopts a more flexible system of regulation than can be had by a system 

devoid of "give." Id. at 399. Those decisions did not require exemptions or less stringent 

standards for malfunction events as the commenter suggests.

EPA’s overall approach to malfunctions is also not inconsistent with the NRDC v EPA, 859 F. 

2d 156, 207(D.C.Cir. 1988) and Marathon Oil Co. v. EPA, 564 F.2d 1253, 1272 (9th Cir. 1977)

cases cited by the same commenter. Although neither case is directly on point and the NRDC 

case’s discussion of technology-based standards is dicta, these cases don’t require exemptions or 
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less stringent standards for malfunctions either. The regulatory affirmative defense included in 

today’s final rule is consistent with Marathon Oil’s holding under the Clean Water Act that EPA 

must formalize its approach to upsets. But see, Weyerhaeuser v Costle, 590 F.2d 1011, 1057-58 

(D.C. Cir. 1978)(holding that an informal approach is adequate).

One commenter maintains that the absence of emissions data creates a duty for the Agency to 

gather the data needed to set specific standards for SSM or, if developing such information is not 

technically feasible, setting work practice standards for SSM periods. However, the statute 

permits EPA to use available information and imposes no affirmative duty to gather information. 

Cf. Cement Kiln Recycling Coalition v. EPA, 255 F. 3d at 867. Consequently, EPA does not 

accept the commenter’s suggestion.

Work practice options

Comment: Many commenters (2841, 2844, 2845, 2874, 2887, 2890, 2929, and 3218) stated that 

EPA should propose either work practice standards as a viable alternative to the current ongoing 

SSM litigation (General Provisions, 40 CFR 63) or suspend efforts to establish SSM limits 

during this rulemaking and consider a separate regulation. According to the commenters, work 

practices would be appropriate given the technological and economic limitation involved with

applying a valid measurement method. Commenters 2841, 2844, and 2845 included a work 

practice plan suggestions and a sample SSM outline and plan as part of their comments. As an 

alternative, EPA should initial a separate rulemaking effort to address SSM emissions once more 

information on SSM emission is available. Reasons stated for a work practice standard include 

the following:

 EPA, in setting a MACT floor, must take into account the variability of the best 

performing source by including emissions during periods of SSM.

 The proposed compliance requirement means that mercury emission cannot be practically

measured during SSM.

 Accurate quantification of the mass of mercury emitted per million tons of clinker 

produced cannot be assured during SSM.

 During SSM, low kiln feed which in turn causes clinker production to be very low will 

reduce mercury emission levels to the point they are below the point of accurate 

measurement.

 During startup, mercury emissions are divided by a very small clinker production rate 

leading to increased mercury emission rates per unit. 

 Also during startup, it is anticipated that mercury emission rates will spike as ductwork 

heats and any absorbed mercury compounds are released or due to other transient affects.

 During shutdown, kiln feed and clinker production is decreasing to zero and mercury

emissions are greatly exaggerated which also leads to increased errors of mercury rates 

per unit.

 Units equipped with wet scrubber or activated carbon control devices are not operated 

during startup until specified kiln operating parameters are met in order to protect the 
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control device from damage and therefore active controls are not functioning during the 

start-up and shut-down period for some kilns.

 For mercury CEMS used in the electric utility industry, during SSM, the sample gas 

molecular weight changes due to the reduction in CO2 concentrations which affects the 

accuracy of mercury measurements.

 For HCl and THC, changes in moisture and oxygen concentration, kiln volumetric flow 

rate, kiln feed, and fuel firing will result in unreliable emissions measurements. 

 PM CEMS monitoring data will not accurately reflect actual emission during SSM 

because of technical difficulties, and excessive testing costs; stability of the PM CEMS; 

and affects on CEMS operations due to differences in fuels burned, firing rate, and feed 

rate.

Response: The commenters indicated that certain features of the standards could not be 

measured (those which are normalized to production), but not that the HAP itself was incapable 

of measurement. Thus, EPA does not see that the criteria of section 112 (h) have been satisfied 

here. The standards in the final rule are not normalized to production for the reasons provided in 

the public comments. SSM conditions should not be contained in correlation tests because they

are usually short lived, and erratic and probably not repeatable. that the correlation is developed 

under normal operating conditions because that is typical of the majority of time and SSM 

emissions are then quantified based on that correlation

Comment: One commenter (2845) stated that EPA should address SSM through the use of work 

practice standards that include:

 Preventive maintenance activities intended to minimize malfunctions and unplanned 

shutdowns of air emissions control systems

 Procedures to be followed to minimize HAP emissions during kiln startup and during 

planned shutdowns

 Procedures for detecting and remedying malfunctions that result in excess emissions that 

include a determination of the cause and corrective actions.

The commenter has provided a sample SSM plan as an attachment to their submitted comment.

Response: See previous response.

Consideration of SSM in mercury standards

Comment: Several commenters (2845 and 2855) stated that EPA’s 30-day rolling average limit 

for mercury does not consider the periodic maintenance shutdown of the raw mill. The raw mill 

is generally shut off for scheduled maintenance about 15 percent of the time. However, there are 

times where unscheduled shutdowns do occur. In addition, the raw mill operation is interrupted 

when feed storage silos are full. Depending on the specific plant, the mill downtime could have a 

major impact on the average emission during that period. This will have an impact on mercury

emissions during that month, resulting in substantial outliers in the 30-day data sets. To ensure 
185

these outliers do not result in the facility being out of compliance for the proposed rule, any 

mercury control strategy to be considered by the plant would need to take this possibility into 

account. As a result, the cost of the mercury control strategy is greater than would be the case if 

these types of maintenance issues did not occur. An alternative that could be considered by EPA 

would be to provide some form of exception for shut-down, maintenance, and start-up.

Response: The comment does not give EPA a sufficient view of the predicament faced by the 

source to indicate that compliance during startup, normal operation, and shutdown periods is 

impracticable. In fact, the description of the scenario presented by the commenter leaves ample 

room for the Agency to interpret that compliance depends on source-specific conditions, operator 

discretion, and a variability in emissions with indeterminate causes among shutdown and restart 

events. For instance, an unscheduled shutdown may or may not share the emissions profile of a 

scheduled shutdown. A prior comment alluded to “impracticable immediate shutdowns.” Given 

the averaging periods built into the standard which accommodate spikes, and the generally less 

challenging conditions obtaining during startup and shutdown conditions (when less mercurycontaining material is input to the kiln), EPA does not accept, in the absence of any data, that 

unscheduled shutdowns, impracticable immediate shutdowns, and scheduled shutdowns all, 

somehow, make compliance impossible.

Clarifications, corrections

Comment: One commenter (2845) stated that §63.1342 indicates that 63.6(f)(1) Compliance 

with Emission Standards, is not applicable to Subpart LLL. If this is the case, §63.6(e)(3) 

Startup, Shutdown Malfunction Plans, should not be applicable as the SSMP provisions are no 

longer needed if the facility cannot utilize the SSM exemption provided for in Subpart A. The 

commenter suggested that in Table 1 to subpart LLL of Part 63 – Applicability of General 

Provisions, 63.6(e)(3) Startup, Shutdown Malfunction Plan will not be applicable to subpart 

LLL.

Response: The EPA agrees that if a source may no longer avail themselves of an exemption for 

startup, shutdown, or malfunction, then a startup, shutdown, and malfunction plan is no longer 

necessary. The applicability of the requirement to have an SSM plan has been deleted. .

Emission standards and SSM exemptions

Comment: One commenter (2846) disagreed with EPA’s proposal to not apply the SSM 

exemptions to the emissions standards in this proposed rule. The commenter provided two 

options to address emissions during SSM events: 

 SSM emissions could be treated as de minimis emissions; and

 EPA needs to establish work practice or operational standards that would apply during 

SSM periods.

Response: See preamble to final rule and earlier responses as to why no showing has yet been 

made as to why work practice standards are permissible here.
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Area sources

Comment: One commenter (2887) stated that with respect to area sources, the EPA could utilize 

its discretion under §112(d)(5) to impose management practices to limit emissions during SSM 

events.

Response: EPA interprets management practices to mean actions homologous to work practice 

standards. See the preamble to the final rule and earlier responses as to why no showing has yet 

been made as to why work practice standards are permissible here.

Continuous monitoring of PM and vapor phases of all HAP metals

Comment: One commenter (2638) stated that with the inclusion of SSM emissions subject to the 

standards, PM and vapor phases of all HAP metals including mercury should be continuously

monitored. CEMS would be required to measure emissions during randomly occurring 

malfunction events. PM is not expected to be a good surrogate for HAP metals during SSM 

events in which emissions, control of these emissions, the chemical state of the emissions and the 

partitioning between phases could and in realistic circumstances would be expected to be 

different from those during normal operation.

The use of multi-metal CEMS methods would allow all of the urban HAP metals including 

mercury and all phases to be continuously monitored with a single CEMS. This option would be 

simpler, more reliable and have lower initial and on-going costs than the only other option 

consisting of two CEMS, one for PM and one for mercury vapor.

Commenter 2638 recommended that SSM events be included in the standard, and that HAP 

metals emissions be monitored using CEMS.

Response: EPA sees no reason to believe that the surrogacy relationship would be altered by

startup, shutdown or malfunction events.

Use of PM as a surrogate for non-volatile HAP metals – in this very industry – has already been 

upheld. See National Lime II, 233 F. 3d at 639. See the preamble discussion under final testing 

and monitoring requirements for more information. 

2.11 Economic Impacts

Control technology performance uncertainties

Comment: In order to estimate the economic impact of the proposed rule, commenter 2845 

examined the need for controls and the likely controls and identified the following as issues with 

the level of performance that each emissions control technology will achieve when applied to 

meet the proposed standards (additional details are presented in Appendix 12 of the commenter’s 

submittal):

 There is only one kiln with an RTO and we do not know how well an RTO will work on 

kilns with differing profiles of organic emissions.
187

 It was assumed that wet scrubbers will reduce HCl emissions in the presence of high SO2

levels but there are technical concerns with the successful control of HCl in that 

circumstance.

 No one has applied activated carbon to a kiln exhaust to achieve either the THC or the 

mercury control levels needed to comply with this standard. In addition, there is an 

expectation that a single carbon system can control both mercury and THC but that has 

not been demonstrated. At present, carbon systems for THC are designed differently from 

systems for mercury.

 Wet scrubber performance in controlling mercury is variable and some of the mercury

captured is reemitted as operating modes change. There is evidence that some units will 

gain very little mercury control with a scrubber due to the form of the mercury in their 

exhaust.

 There is strong evidence that RTO are not capable of reducing emissions to below the 

proposed THC standards.

 There is significant uncertainty as to whether a wet scrubber can reduce HCl levels to 

below the proposed HCl standards.

 Not all kiln locations have the natural gas service needed to fire an RTO.

 Not all kiln locations will have access to the water needed to operate a wet scrubber.

Commenter 2845 stated that there are key uncertainties associated with the control performance 

assumptions used by EPA but in order to develop their own analysis of the cost of controls, has 

developed its own control performance assumptions: 

 An RTO will cut THC emissions by 95 percent and a scrubber will precede the RTO. 

Doubts that an RTO can be operated consistently below 7 ppm of THC without regard for 

the starting concentration due to the THC associated with the combustion of the natural 

gas and the emissions during switching of the thermal beds. The commenter assumes for 

their analysis that RTO will be able to consistently reduce emissions below the 7 ppm 

limit even though the one commercial application of an RTO on a kiln has not done so.

 A scrubber will control mercury, on average, by 50 percent. It is clear that actual 

performance is a function of the mix of oxidized and elemental mercury which can be 

highly variable.

 Any ACI system will used to control both mercury and THC. ACI will reduce organics 

by 50 percent due to their poor performance in adsorbing light hydrocarbons. Any ACI 

system will include a dedicated bag house to capture the carbon ladened dust. That bag 

house will be 50-66 percent of the size of a new bag. ACI with a bag filter will reduce 

mercury emissions by 75 percent.

 A unit that adds both ACI, with a bag house, and a scrubber is assumed to have overall 

mercury control of about 85 percent.

 The new PM standard will require that all units have a bag house. For this analysis, the 

exact performance of the bag house is not addressed but simply it is assumed that all kilns 

must have one. However, if a unit has an ESP and adds ACI with a bag house, it is 

assumed that the existing ESP will not need to be replaced.
188

 To the extent a unit has baseline stack test HCl emissions over the standard, it is assumed 

that a wet scrubber will be needed. The exact performance of the scrubber is not known.

 Another compliance requirement that will need to be consider for its cost will the 

installation and operation of CEMS for THC, HCl and mercury for each regulated stack.

 Scrubbers installed to meet the limits under this rule will reduce SO2 to some degree. To 

assess that impact, we have surveyed scrubber suppliers and test data and developed the 

following assumptions: scrubbers will provide between 90 percent and 95 percent control 

for SO2 but will not control below 15 ppm of SO2.

Response: EPA is aware that the actual performance of any control device will depend on a 

number of factors and will likely vary to some unknown degree among kilns. EPA made based 

its estimates of performance on available performance data including data for the cement 

industry as well as other relevant industries. In some cases that data were limited. For example, 

EPA’s estimate of scrubber performance for wet scrubbers on mercury emissions was based on 

the test conducted at 5 kilns. ACI performance was based on the experience of the utility

industry, as well as a pilot test conducted at one portland cement kiln. In estimating cost impacts 

and emission reductions, we calculated the removal efficiency that would be required to comply 

with the final limits and assigned a control device based on the reduction that would be 

necessary. The cost impacts are conservative in that for every kiln, we assumed that one or more 

control devices would have to be added. We believe that we have overstated what actual costs 

will be for the industry. While we may not accurately predict the controls that each kiln will 

eventually install to comply, we have provided an estimated cost of compliance and accounted 

for the fact that the emission limits will require expenditures by the industry to comply. The 

actual cost associated with compliance is not factored in the decision of what the level of the 

standard should be. EPA must set the standards based on the best performers, regardless of the 

means by which they are the best performers.

The commenter took issue with the controls and level of performance used by EPA in its analysis 

of impacts. Regarding the ability of RTO to adequately control organic emissions, a currently

operating RTO with several years of operating experience is controlling THC on a long-term 

basis to an average of about 5 ppmvd at 7 percent O2 measured as propane. Furthermore, as a 

result of additional long-term THC data received after proposal, EPA has increased the THC 

limit to 24 ppm for promulgation. In addition, sources have the option of complying with the 

alternative limit for organic HAP. We acknowledge that a few sources may find it necessary to 

add RTO because of the level of control necessary, although we believe that most kilns can be 

adequately controlled using ACI systems that get an estimated 50 percent control of THC (due to 

the presence of lighter hydrocarbons such as methane and ethane that are not as effectively 

removed by RTO as heavier compounds) and an estimated 80 percent control of other organic 

HAP. Where RTO are installed, they will be expensive, due in part to the fact that the RTO must 

be preceded with a wet scrubber in order to remove SO2 that can foul the RTO. However, we 

have found that only 10 kilns nationwide may need to install RTO.

We also agree with the commenter that RTO use may not be feasible in areas that lack access to 

natural gas supplies. However, as stated above, the number of sites where we expect RTO to be 

necessary is limited. Based on information available at the U.S. Energy Information 

Administration, all six states where kilns potentially needing RTO are located appear to have 
189

access to natural gas. We do not believe that water availability will be a limiting condition in 

these locations.

The commenter had concerns about the ability of wet scrubbers to remove HCl in the presence of 

SO2. We agree that the wet scrubbers currently on U.S. cement plants are designed to remove 

SO2, rather than HCl. However, an EPA review of HCl emissions from 21 plants indicated an 

average HCl concentration of 12 ppm, and a maximum HCl concentration of 55 ppm. Therefore, 

required HCl removal efficiencies to meet the 3 ppm emissions standard are expected to be much 

lower than 99 percent for virtually all kilns. A preliminary review of data gathered from a 2010 

Information Collection Request (ICR) for Electrical Generating Units indicates that wet 

scrubbers utilizing lime will be able to provide the necessary collection efficiency to meet the 

3 ppm emissions standard.

EPA believes the commenter’s concern over the performance of ACI systems are not well–

founded, based on the experience with the use of ACI systems for both mercury and organic 

emission controls in other industries, including medical waste incineration and coal fired boilers.

The ACI system installed at Ash Grove in Durkee, OR is expected to achieve over 80 percent 

reduction in mercury emissions. Based on pilot tests, removal efficiencies of over 90 percent 

were achieved, depending on the type of carbon and the injection rate.

As noted by the commenter, scrubber performance on mercury can be variable and depends on 

several factors, such as the mercury species present, the presence of chlorine in exhaust gases, 

and the liquid injection rates. Tests conducted on the scrubbers currently in use in the cement 

industry showed removal efficiencies from 50 percent for one scrubber to over 80 percent at two 

scrubbers. These removal efficiencies were the average of tests conducted during raw mill on 

and raw mill off conditions. Usually during the raw mill off period, removal efficiencies are 

higher, due to the presence of greater concentrations of oxidized mercury than during the raw 

mill on phase, when most of the mercury is in the elemental phase. We agree that wet scrubbers 

may not perform as well as ACI systems on mercury, and we believe that ACI systems, which 

have higher removal efficiencies and are less expensive to install and operate than scrubbers, will 

be the predominant control method used. Our impact and economic analyses are based on this 

assumption.

Where both ACI and wet scrubbers are installed, the combined efficiency of the two systems on 

mercury control will vary. We expect that ACI systems with removal efficiencies of 80 percent 

or better will remove most of the mercury and that, where mercury concentrations in the exhaust 

gas stream are low to moderate, wet scrubbers will not impact final mercury emissions 

significantly. Our impacts analysis uses this assumption. However, in situations involving high 

mercury concentrations, we believe that scrubbers after ACI systems will have significant 

impacts on the final emissions. In our analysis, this was a factor for only two kilns that have 

extremely high mercury emissions.

We agree with the commenter’s statements that, where a facility currently operates an ESP and is 

expected to install an ACI system (including polishing baghouse), in most instances they would 

not need to replace their ESP. Our impacts analysis uses this approach. We also considered the 

costs of CEMS in our analysis as suggested by the commenter.
190

Regarding the commenter’s statement that scrubbers will not control SO2 below 15 ppm, outlet 

test data from one cement plant report SO2 levels well below the 15 ppm level. (Memo, Bahner, 

Laney, Barnett, Summary of Cement Kiln Wet Scrubber and Lime Injection Design and 

Performance Data, May 29, 2008, Docket EPA-HQ-OAR-2007-0877)

Comment: One commenter (2891) stated that the goal of MACT standards in general is to 

achieve 90 percent or better reductions in the targeted hazardous air pollutant emissions. Some 

estimates place the likely reductions from this proposed regulation as low as the low to mid-80 

percentile for reduction. If that is correct, the commenter requested that EPA describe in plain 

terms the Agency’s justification for obtaining reductions below 90 percent.

Response: MACT standards must be of minimum stringency reflecting performance which is 

the average of a select group of best performers, or the performance of the best-controlled similar 

source, and may be more stringent. There is no specific emission reduction percentage, however, 

which constitutes MACT.

Alternate impact analysis

Comment: One commenter (2845), in estimating the impacts of the proposed rule, stated that 

there was insufficient data to perform a kiln-by-kiln analysis of controls. Instead they used 

available emissions data for subsets of kilns and extrapolated to the total population assuming 

170 kilns needing to comply. In order to estimate the total number of RTO, scrubbers, ACI, and 

bag filters needed to comply with the proposed limits, the commenter listed the steps taken to 

profile the entire population of kilns (see Appendix 12 to the commenter’s submittal for details).

One of the key differences between EPA’s assessment and the commenter’s assessment is that 

the commenter expects a larger number of RTO because of the limited performance of activated 

carbon on controlling light hydrocarbons and the need to design the carbon system to control 

both mercury and THC. According to the commenter, a number of kilns will be at risk of noncompliance even with the installation of the best available controls. 

The commenter (2845) took issue with EPA’s assumption of a substantial secondary benefit in 

the form of SO2 reductions from the installation of wet scrubbers under this rule. The commenter 

stated that there is significant uncertainty about the nature of a scrubber designed to reduce HCl 

or mercury or both and whether it will operate in a manner that provides the same level of SO2

control as a dedicated SO2 scrubber. To assess the impact of wet scrubbers on SO2 emissions, the 

commenter used the SO2 emissions from the ISIS model and average flow volumes to calculate 

the stack outlet SO2 concentration in ppm for each kiln. The commenter then calculated the 

control efficiencies that would be required and control efficiencies that could be achieved for 

each kiln assuming that the lowest achievable scrubber outlet concentration of SO2 is 15 ppm 

based on communications with a scrubber vendor. The commenter estimated SO2 control ranging 

from 72-78 percent over the entire SO2 inventory. 

One commenter (2845) did not agree with EPA’s assumptions for control technology

effectiveness impacts, controlled emissions estimates, and costs for installing/operating the 

various control technologies and are listed as follows: 
191

 The costs for limestone wet scrubbers as estimated using EPA’s (ISIS) model and 

production assumptions were compared with best available control technology

(BACT)/best available retrofit technology (BART) cost calculations using site-specific 

gas flow and SO2 concentrations for these same facilities. The results of the comparison 

of the two methods can be summarized as follows:

– The capital and annual cost projections using the BACT/BART cost estimates were 

several times greater than those calculated by EPA.

– The SO2 concentration in the kiln gas and the presence of contaminants in the 

synthetic gypsum (syngyp) produced will determine whether a gypsum credit or a 

sludge disposal cost will be incurred for the scrubber sludge. The ISIS model always 

assigns a credit, and the BACT/BART analysis assigns a cost for disposal. These 

costs/credits will be site-specific.

– Two key capital and operating costs that are not included in EPA’s cost analysis are a 

limestone preparation plant to grind limestone to the fineness required for the LWS 

and the handling equipment used to handle the syngyp created by the LWS. The 

syngyp has high moisture content and cannot be handled by the equipment utilized to 

handle natural gypsum. The additional costs for these two systems were provided by

the commenter.

– Other observed discrepancies impacting annual variable costs include costs for 

natural gypsum and costs for onsite or offsite wastewater treatment. If onsite 

treatment is utilized, additional capital costs must also be included.

– The ISIS model does not include the potential for additional capital costs at those 

plants that will require the kiln ID fan to be replaced. This is particularly likely where 

other control devices such as an RTO or ACI are also required by the new NESHAP 

requirements. The need for a new ID fan will be site-specific.

Response: As a result of comments, we examined our costs (including scrubber costs) and made 

several adjustments, including revisions to the exhaust gas flow rates, power demand, and water 

usage. As an illustration of the effects of these revisions, at proposal, the capital cost for a 1.2 

million tpy kiln was $9.3 million; the revised estimate is $25 million. Annualized costs increased 

from $1.6 to $3.6 million. Earlier responses in this section address other issues raised by the 

commenter.

Comment: One commenter (2844) stated that the exhaust flow rates reported and utilized in the 

cost of control section underestimates the exhaust flow rates to be controlled by using 

inconsistent factors, missing certain sources of flow, and using dry instead of actual (wet) flow 

rates in the analysis.

Response: In response to this comment, EPA investigated its gas flow rate estimating approach. 

Upon looking at additional data that had been supplied by industry, it did appear that stack gas 

flow rates generally exceed the original flow rates used. From the data, it appears that other 

sources of gas flow dilute the kiln exhaust and increase the total flow rate beyond what is 

expected at the kiln exit. Based on a review of the additional data and review of operating cost 

estimates specifically for scrubbers, changes were made in the operating cost equations. Changes 

in the exhaust gas flow rates also affected costs of all control equipment costs as equipment costs 
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are generally a function of exhaust gas flow rates. The details of this analysis of exhaust gas flow 

rates and changes in operating cost equations is documented in memorandum from Staudt, 

Andover Technology Partners, to Srivastava, Torres, Barnett, US EPA, “RE: Wet Scrubber Cost 

Algorithms,” February 26, 2010.

Comment: One commenter (2844) stated that EPA’s analysis confuses capacity of a plant and 

the actual production of a plant. This approach overstates the emissions, and understates the 

control needs and costs.

Response: In our analysis, we chose capacity because actual production can vary substantially

over time. We disagree with the commenter’s assertion that using capacity maximizes emissions 

and costs.

Comment: One commenter (2844) stated that for concentration-based limits, EPA unreasonably 

assumes that exhaust is at 7 percent oxygen when sizing and costing out controls. Higher oxygen 

levels occur in kiln exhaust due to others sources of flow to the kiln stack. As a result, the overall 

flow to the stack will be greater than has been assumed in the EPA cost analysis. With higher 

flow will come larger control systems and added cost. 

Response: As noted in a previous response, as a result of comments, we investigated our gas 

flow rate estimating approach and made changes that affected the control equipment costs. The 

details of this analysis of exhaust gas flow rates and changes in operating cost equations are 

documented in a memorandum from Staudt, Andover Technology Partners, to Srivastava, 

Torres, Barnett, US EPA, “RE: Wet Scrubber Cost Algorithms,” February 26, 2010.

Comment: One commenter (2844) stated that in the assessment of HCl and THC impacts, EPA 

assumes each kiln is running at full capacity 365 days per year, which is impossible. A more 

reasonable number for days of operation is 330 days.

Response: EPA assumes 330 days of operation in the cost and impacts analysis.

Comment: One commenter (2844) stated that scrubber power demand is presented at 3kWh/ton 

clinker, which is too low. There appears to be a minor error in the calculation that is done in 

converting units but the main problem is that duct work pressure drop has not been accounted for 

and the exhaust flow is too low. Thus, in Section 2.3.5 secondary impacts are based on 

unreasonable assumptions. The commenter provided examples of power costs that are higher 

than those assumed in EPA’s assessment. 

Response: As noted in a previous comment, as a result of comments, we examined our scrubber 

costs and made several adjustments, including revisions to the power demand, resulting in a 

change in our control cost estimates.

Comment: One commenter (2844) stated that other environmental impacts (Sections 2.4 and 

2.5) include errors. The commenter provided a list of specific errors in the evaluation of other 

environmental impacts:
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 Scrubber make-up water is given as 30 gal/ton clinker. In NSPS rulemaking, however, it 

was given as 105 gpm for a 1,200,000 tpy plant, i.e. 42 gal/ton clinker (see EPAHQOAR-2007-0877-0008, table 9, p.17), which is 12 gallons more than the new number.

 ACI solid waste is given as 3 lb/ton clinker in Exhibit 7 but later a figure of 6 lb/ton 

clinker is given.

 Scrubber solid waste is omitted. It is assumed by EPA that all the scrubber waste can be 

incorporated into cement, but EPA has not demonstrated that this can be done while 

meeting product standards.

 EPA assumes that CKD can also be incorporated into the cement but EPA has not 

demonstrated that this can be done while meeting product standards.

Response: As noted in a previous response, we examined our scrubber costs in response to 

comments and made several adjustments, including scrubber water usage, resulting in a change 

in our estimates. In response to this comment, we have corrected our ACI solid waste estimate in 

section 2.5 to indicate 3 lb/ton clinker, consistent with the estimate provided in Exhibit 7. Our 

assumption regarding scrubber solid waste was based on a discussion with plant personnel, who 

indicated that scrubber slurry is dried and added to the clinker as gypsum.

Comment: The following are comments from commenter 2845 regarding EPA’s determination 

of costs associated with the installation and operation of ACI for the control of mercury and 

THC:

 A more refined economic analysis performed for an ACI system with a polishing 

baghouse resulted in a capital cost factor of $13.33 per ton clinker and an annual cost 

factor of $3.91 per ton clinker, both of which are more than four times the values used by 

EPA.

 The estimated levels of emissions control for ACI used by EPA are overly optimistic; 

achievable industry average levels of control for ACI would be 50 percent for THC and 

75 percent for mercury. Depending upon the form of mercury in the exhaust gases, an 

ACI system used in conjunction with a wet scrubber is expected to provide a combined 

control efficiency for mercury of 85 percent. 

 EPA overestimated the amount of solid waste generated from ACI systems. Based on the 

vendor-suggested injection rate of 12 lbs activated carbon per million (actual cubic feet 

per minute [ACFM]), an ACI system will generate approximately 1.68 lbs solid waste/ton 

clinker versus EPA’s estimate of 3 lbs/ton. 

Response: Without any supporting data from the commenter to substantiate their estimates for 

ACI costs, mercury emission reductions, and ACI solid waste, we are unable to evaluate the 

commenter’s assertions. We estimated the costs of using an ACI system and polishing baghouse 

to control mercury emissions from cement kilns using control costs recently developed for actual 

electric utility boilers with exhaust gas flow rates comparable to those for cement kilns. We 

estimated the mercury emissions control based on testing conducted on an ACI system at a 

cement plant, which showed mercury removal efficiencies over 80 percent at carbon injection 

rates of 10 lbs per million acf. The ACI solid waste estimates were based on data provided in 

Docket item II-B-67, Docket A-92-53.
194

Comment: One commenter (2845) provided the following comments regarding EPA’s

determination of costs associated with RTO systems for control of THC.

 The pollutant control matrix shown in ISIS incorrectly lists PM, mercury, and HCl as 

pollutants addressed by the RTO control option

 EPA derived a capital cost factor of $9,598 per dscfm

0.6 to estimate the capital cost of 

installing an RTO system on a cement plant from information available on the only

currently operating existing installation within the cement industry. However, the 

correlation required flow in dscfm, and EPA used flow in units of standard cubic feet per 

minute (scfm), which includes moisture in the gas stream resulting in a substantial level 

of error for EPA’s estimation. 

 To estimate annual operating costs, EPA utilized an empirical formula with several 

variables, some of which are dependent upon kiln type. Based on the information used as 

EPA’s basis, the empirical formula vastly underestimates the annual operating cost of the 

RTO system. The typical annual maintenance materials costs for an RTO system would 

be around $503,000 per year for the 1.2 million ton per year example facility.

 Using a more recent quote from the vendor for an existing RTO a projected capital cost 

factor of $11,034 per dscfm0.6, which is about 15 percent greater than that utilized by

EPA was estimated for a 1.2 million tpy kiln. The analysis projected an annual operating 

cost for an RTO on a precalciner kiln of $4,574,531 as opposed to EPA’s estimate of 

$1,199,996, over four times that estimated by EPA. 

 The estimated levels of emissions control for the RTO used by EPA are overly optimistic. 

Recommended, and achievable, industry average levels of control for an RTO would be 

95% for THC although an RTO system is not capable of maintaining a THC emission 

level below 10 ppm. Therefore, many kiln systems with elevated, but not extreme, levels 

of THC in the exhaust would not be able to comply with the proposed standard of 7 ppm 

through installation of an RTO system.

 EPA underestimated the electrical power and natural gas fuel requirements for RTO 

systems. Based on a manufacturer’s quote, the power demand is 46.7 kWh/dscfm and the 

natural gas requirement is 1.26 million British thermal units (MMbtu)/dscfm. EPA’s 

estimates were 30.9 and 0.73, respectively. 

 EPA underestimated the amount of secondary impact emissions from operating the RTO 

systems due to the underestimated power demand and fuel requirements for the 

installations.

Response: EPA acknowledges commenters’ input regarding RTO control costs. However, EPA 

expects 10 or fewer RTO’s to be installed as a result of this rulemaking. Further refinements to 

the RTO costs would not change the underlying MACT floor determinations or emissions 

standards. Revised RTO costs may change the estimated cost burden to the industry, but RTO 

costs are expected to be relatively small in relation to the total control costs to the industry.

Comment: One commenter (2916) stated that EPA should consider indirect effects of the 

Cement Kiln NESHAP, including increased energy consumption, increased water consumption, 

and increased dependence on foreign supplies of a strategic commodity. The commenter 
195

suggests that the EPA inadequately addresses these indirect effects when explaining the 

justification for the MACT standards set in the proposed Cement Kiln NESHAP.

Response: In considering whether to adopt beyond the floor standards, EPA did take notice that 

additional controls would necessitate more energy use, and could lead to increased water usage 

and waste generation. These are additional reasons for not adopting beyond the floor standards 

(along with high costs for limited reductions with consequent poor cost effectiveness). EPA does 

not consider non-air quality impacts at the floor to be so extreme as to invalidate what otherwise 

is best performance, however.

Comment: One commenter (2916) provided the following cost issues comments regarding 

EPA’s determination of costs associated with installation and operation of baghouses and 

membrane bags:

 Based upon information received from National Cement on a recent baghouse 

installation, the commenter believes that capital costs for baghouses have been 

understated by EPA by nearly a factor of two.

 The pollutant control matrix shown in ISIS incorrectly indicates HCl and THC being 

associated pollutants for the baghouse membrane bag (BHMB) and membrane bag 

(MBR) control options. 

 In the monitoring cost section for PM, it is stated that the CEMS Cost Model assumes 

each baghouse has 5 compartments which seems off by a factor of probably 2 or more 

and raises a question as to the size of the baghouse EPA has assumed would be necessary 

for the kilns. In fact, EPA assumes that the clinker cooler baghouse has the same number 

of compartments as the kiln baghouse. Kiln baghouses are usually at least 50 percent 

larger than cooler baghouses, depending upon the type of cement process.

 EPA assumes that an existing baghouse would need a simple bag replacement to comply

with the PM limit and assumes that the costs to replace only membrane bags is the 

difference in cost between the new reverse air baghouse with fabric bags and a new 

baghouse with membrane bags. Many older baghouses will need major 

repairs/retrofitting or even outright replacement to use newer membrane bags and still 

meet the PM standard. The number of facilities that would fit this category and the cost to 

repairs/retrofit on a per facility basis is unknown. EPA’s cost estimate assumes reverse 

air baghouses would be the standard replacement, but most new baghouses on kiln 

systems are pulse-jet, which may have higher costs than what EPA assumes.

 For PM, EPA used their Air Pollution Control Cost Manual Sixth. The background 

documents contain no information on what assumptions EPA used to generate the costs.. 

Without the detailed background information on the specifics of the size and other details 

regarding the particulate control device used for the cost estimate, it is impossible to 

know if the cost estimates are representative of real world installations or whether the 

size of the baghouse used by EPA was based upon ACFM or scfm, or, if it was based 

upon scfm, what assumed operating temperature was used. There are additional costs 

associated with membrane bags as follows:

– Higher cost of membrane bags (same area as conventional bags).
196

– In most cases, lower emissions will also require lower air to cloth ratios to limit 

cleaning and emissions.

– Reduced bag life to avoid operating with failed bags.

Response: First, it should be noted that the final rule is not requiring bag leak detectors, but PM 

CEMS. Second, in our cost analysis, we used the reverse-air baghouse design as the basis for our 

costs in order to be conservative, based on our understanding that reverse-air designs would be 

more expensive than pulse-jet designs. Third, the OAQPS Control Cost Manual has been the 

standard reference used by EPA in costing emissions control equipment, where actual applicable 

cost data are unavailable. We assumed membrane bags were about four times more expensive 

than standard bags. We used vendor information regarding the superior performance and life of 

bags.

Comment: One commenter (2844) stated that Section 2.7 includes error in the evaluation of cost 

impacts in the environmental analysis:

 Andover 2008a at p27 provides figures for gypsum produced. In a wet scrubber it is not 

plaster (or anhydrite CaSO4 M=136) that is made, but bihydrated gypsum (CaSO4.2H2O 

M= 172). In addition, that gypsum is wet (about 12%). So, 64 tons of SO2 removed 

should make 172*1.12 = 193 tons of gypsum.

 Capital cost for ACI seems very low ($2.41/ton clinker) based on the commenter’s 

discussions with vendors.

Response: As noted previously, wet scrubber costs have been revised based on comments 

received.

Comment: One commenter (2845) provided the following comments concerning the CEMS cost 

modeling approach:

 The commenter will need access to EPA’s completed cost model to fully assess EPA’s 

assumptions.

 The useful life of CEMS for purposes of estimating annualized costs is unclear and 

confusing in the EPA background documents. 

 All costs should be expressed in 2005 dollars for ISIS and for EPA’s other cost and 

benefits estimates for the NESHAP. However, it appears that the CO CEMS costs (that 

EPA evidently uses to represent costs for THC CEMS in the NESHAP costing) was 

completed using 2003 dollars. Based on the documentation, the commenter cannot 

determine for what year the CEMS Cost Model provides costs.

 It is anticipated that every facility will need to install a new CEMS building; even if a 

building already exists, location issues associated with the new control technology will 

dictate that a new building be constructed. Also, all new CEMS for mercury and other 

pollutants are built at the manufacturer or integrator place of business and shipped in the 

shelter as a unit. The cost for on-site assembly is prohibitive and greatly diminishes 

quality.

Commenter 2845 has more specific CEMS System Comments for mercury, HCl, THC, and BLD 

as follows:
197

 For mercury CEMS, 

– It is expected that the capital cost for purchase and installation of a single mercury

CEMS is in the range of $300,000 – $500,000. The initial testing for certification 

adds $35,000.

– The extra elemental mercury calibration gas generator that is needed to meet the QA 

criteria in the recently published EPA Traceability Protocols for Elemental Gas 

Generators is estimated to cost $45,000. This field reference calibrator could be used 

to QA generators at multiple plants.

– Upgrades to plant compressed air systems are required for the nitrogen dilution 

systems (most widely used Thermo systems).

– Using an average capital cost of $500,000 for contemporary mercury CEMS is more 

realistic.

– Mercury CEMS on-going operation and QA will require one dedicated plant person 

per mercury CEMS. 

– The annual cost to perform the required RATA is $25,000.

– The vendor supported maintenance agreement is estimated to cost approximately

$30,000 per system.

– Although, the useful life of the system is yet unknown; it is assumed to be a 

maximum of 10 years; but, certain system components may have a shorter life.

 For HCl CEMS,

– The industry believes installation and certification of HCl CEMS as currently

proposed is expected to cost between $225,000-$250,000 (including FTIR, oxygen 

monitor, data handling system, heated sampling, calibration gases, and other ancillary 

equipment) in system capital expenses and installation.

– There are no current monitors that can measure at levels required by EPA, and PS-15 

is impossible to meet (requires spectroscopist to review the FTIR data frequently and 

includes numerous requirements no CEMS in the world could meet).

– Due to special sampling requirements, an FTIR system as prescribed by EPA could 

not be part of another CEMS; it would need to have separate dedicated sampling 

equipment (special super hot sampling lines) and separate data acquisition system 

(DAS).

– Estimated capital costs of about $280,000 just to get started on a system are expected.

– Another $30,000 for initial certification of the HCl CEMS is anticipated.

– The total costs for on-going QA are unknown as facilities cannot install and certify

HCl CEMS using PS-5.

– Estimated cost includes one full-time person, plus $30,000 for annual testing, plus 

$20,000 for an annual service agreement.

 For THC CEMS, the Summary of Environmental and Cost Impact document lists 

$137,800-$138,900 for installed CEMS costs, and $41,672 for ongoing costs. However,
198

these are for CO monitors as this document was prepared some time ago and EPA figured 

that industry would go with CO monitors versus THC monitors because they were less 

costly. An FID analyzer with dual range with auto switching to get to the low levels and 

still measure spikes would be estimated at $25,000 as compared to CO analyzer $10,000. 

 For BLDS:

– The commenter (2845) does not understand the basis for EPA’s number for CEMS 

and BLDS monitoring costs. An estimate for the cost of a transmissometer (also used 

as COMS) that meets ASTM D7392-07 for PMDS or a good quality light scattering 

instrument is $35,000. According to our expert on CEMS, a cost of $93,700 is 

sufficient for any of the recommended options on the table: BLDS, PMDS, or COMS, 

assuming monitoring only at a single location.

– A BLDS is needed downstream of each baghouse (kiln, coal mill, by-pass, etc) 

whereas a PMD may be able to monitor co-mingled emissions (e.g., kiln and coal 

mill). We are not clear on the assumptions EPA made. However, on page 17 of the 

Summary of Environmental Costs Impacts of Proposed Revisions to Portland Cement 

NESHAP, EPA assumes 1 sensor per compartment and 5 compartments for kiln 

baghouse, and five more of the same sensors for the clinker cooler baghouse, for a 

total of 10 sensors. Thus, the EPA assumed capital cost is approximately $94,000 for 

10 monitors. However, the assumption of only 5 compartments for each kiln 

baghouse is understated by a factor of at least two times. Thus, EPA’s estimated 

capital cost for BLDS on the basis of 1 sensor per compartment is at least 50 percent 

low.

Response: The cost model is based on vendor supplied data and has been placed in the docket 

for this rulemaking.

RIA and ISIS projections

Comment: One commenter (2845) stated that EPA’s RIA wrongly credited all projected SO2

emissions reductions in 2013 to the NESHAP by assuming all kilns operating in 2005 will be in 

operation in 2013 and will be in compliance. The RIA also assumes 20 new kilns in operation by

2013. The ISIS model projects a lower reduction by taking into account natural plant closures 

and modernizations. The commenter stated that ISIS offers significant improvements over EPA’s 

traditional cost approach. The commenter stated that the ISIS results are based on outdated 

projections regarding future U.S. cement consumption and capacity projections that were 

developed before the severity of the current recessions became apparent. According to the 

commenter, when EPA re-runs ISIS using consumption and capacity projections that accurately 

reflect the impact of the recession, EPA will predict a reduction in kiln emissions of SO2 in 2013 

and the monetized value of the SO2 reduction attributable to the proposed NESHAP will decline 

as will the cost estimated for compliance with the proposed NESHAP.

One commenter (2845) stated that although ISIS offers the potential to eventually provide a 

significant improvement over EPA’s previous economic modeling for the cement industry, 

presently, ISIS is subject to numerous shortcomings in data, assumptions, structure and 

validation. The commenter does not believe that the current version of ISIS provides believable 

estimates of likely economic impacts from the proposed NESHAP or from other potential 
199

environmental requirements. ISIS is so complex and its deficiencies so pervasive that, until it is 

substantially improved, other methods should be used to assess the likely impacts of the 

proposed NESHAP. The commenter provided an initial technical review of the current version of 

ISIS that EPA has used to estimate the costs and economic impacts of the proposed rule and also 

provided comments and criticisms regarding the model and suggestions for improving and 

eventually develops an acceptable version of ISIS. The commenter submitted additional details 

and data as part of their comment. In contrast to EPA’s previous approach, ISIS:

 No longer models the U.S. cement industry unrealistically as a collection of 20 

completely independent regional cement markets, with each cement producer selling 

product in only their own home market;

 Models cement producer behavior as competitive rather than oligopolistic, dropping the 

assumption that producers restrain output in order to raise prices;

 Allows a greater potential role for imports, consistent with historical experience;

 Simulates endogenously the full range of potential responses to regulation instead of 

assuming many of them as exogenous inputs to the model; and

 In many respects uses updated and better data.

However, notwithstanding its commendable modeling objectives and the improvements over 

previous modeling efforts, the current version of ISIS that is used for the NESHAP analysis 

needs substantial improvement before its outputs can be considered to realistically forecast the 

impact of EPA regulatory options. The commenter submitted detailed discussions of its 

recommendations for improvement to ISIS (see Appendix 13 of the commenter’s submittal).

Response: The ISIS Cement Model has been enhanced by updating cement consumption and 

capacity projections, import modeling and transportation matrix. EPA employed both a partialequilibrium economic model and the enhanced version of the ISIS Cement model to analyze the 

impact on the industry and the economy. The final documentation of the enhanced peer-reviewed 

ISIS model has been placed in the docket for this rulemaking.

Comment: One commenter (2845) evaluated the potential economic impacts of the proposed 

rule and estimated that as many as 30 existing plants could be forced to close, with an additional 

12 at high risk of closure which will have significant employment and economic impacts as well 

as collateral environmental impacts as well including a substantial increase in imports from nonU.S. plants that are not subject to stringent environmental standards. This would undermine the 

mercury reduction benefits and increase greenhouse gas emissions from the transportation of 

cement (the commenter provided additional details in Appendix 10 to their comments).

Response: Neither our RIA economic analysis or our ISIS analysis estimated impacts this large. 

Based on our analyses, we believe that up to 10 plants may have reduced capacity utilization 

during 2013 as a result of the impacts of this rule. (Regulatory Impact Analysis: Amendments to 

the NESHAP and NSPS for the Portland Cement Manufacturing Industry, Final Report, August 

2010).

Comment: Several commenters (2844, 2846, 2859, and 2919) stated that the proposed standards 

will have adverse economic impacts. The proposed standards will make it cost and technology
200

prohibitive for some plants to achieve compliance, leading to forced closure of domestic plants 

that will create job losses. The reduction of domestic cement production will require imports, 

elevate costs, eliminate jobs, and constrain infrastructure development.

Greater imports of cement will increase use of fossil fuels used for transportation, and foreign 

sources of cement are manufactured under conditions that are not as environmentally protective 

as in the United States.

One commenter (2919) noted that the EPA should evaluate the potential emissions from the 

production and transport of replacement cement for those markets affected by plant closures. It 

does not appear that EPA has addressed this issue in the preamble to the proposed rule, so the 

commenter recommended that EPA evaluate this before finalizing the rule to ensure that the final 

rule results in a net environmental benefit in the event that it causes closure of cement facilities. 

If EPA chooses to establish a subcategory for facilities with extremely high mercury content ore 

that might otherwise be forced to close, we recommend that it require the highest level of control 

achievable for that subcategory.

Response: In the RIA analysis, EPA modeled price, production, import, and employment 

changes in a partial equilibrium model. In the benefit analysis, EPA estimated disbenefits of 

increased energy consumption quantitatively and the disbenefits of increased production in 

foreign countries qualitatively.

Comment: One commenter (2846) stated that in the current economic crisis, it is imperative that 

U.S. industry maintain sufficient flexibility to improve operations while simultaneously

continuing to improve its record of emissions reductions. EPA’s estimate of the cost of this 

proposed rule – over a quarter of a billion dollars annually – could likely preclude emissions 

control technology development and stifle economic growth, rendering the U.S. cement industry

incapable of competing effectively in the global marketplace. Given the increased infrastructure 

development likely to take place as a result of the stimulus package, Council of Industrial Boiler 

Owners (CIBO) believes that EPA’s capital cost estimate for the cement industry’s compliance 

with the proposed standards is likely inadequate. In imposing MACT requirements, it is essential 

that EPA have realistic cost estimates for its proposed standards, so that the impact of all 

proposed standards can be adequately ascertained by all interested parties.

Response: EPA employed both a partial-equilibrium economic model and the enhanced version 

of the ISIS Cement model to analyze the impact on the industry and the economy. In the ISIS

Cement model, EPA used the latest projections on cement consumption from the Portland 

Cement Association (October, 2009). The cement consumption projections take into 

consideration both the economic crisis as well as the economic recovery maintaining sufficient 

flexibility in the analysis of this rulemaking. The Economic and Impact Analysis for this 

rulemaking using both of these can be found in the rulemaking docket.

SO2 reductions

Comment: One commenter (2845) stated that EPA has overestimated uncontrolled SO2

emissions by about 25 percent as a national total because emissions were estimated as the 

tonnage of SO2 emissions abated by the regulation. As a result, benefits were also overestimated 
201

because SO2 emission reductions were multiplied by a dollar value of benefits per ton providing 

benefits that are a linear multiple of the estimated emissions reduction. It is not clear how EPA 

estimated the total national SO2 emissions in either the RIA or Industrial Sectors Integrated 

Solutions (ISIS) and it is believed that all of the estimates for the 2005 SO2 emissions are 

inaccurate for the following reasons:

 Inaccuracies in the data obtained for the 2002 NEI;

 Inaccuracies in collapsing individual plant data into regional averages or medians by kiln 

type and then into national averages or medians by kiln type;

 Potential inaccuracies in using medians rather than averages;

 The error in multiplying emissions intensity (pounds SO2 per ton of clinker) by clinker 

capacity in contrast to actual clinker production;

 Errors in updating 2002 emission information for individual kilns to 2005 by inflating 

each kiln’s emissions by the national average production increase from 2002 to 2005 

instead of by each kiln’s actual production increase over this period;

 The potential error in including SO2 emissions from hazardous waste-burning kilns in the 

inventory of 2005 baseline emissions that might be affected by the proposed NESHAP. It 

is not clear whether EPA made this error or not;

 The commenter has access to a more up-to-date and accurate database which when 

compared with EPA’s estimated results, the commenter’s estimated results were 20 

percent lower; therefore, because EPA overestimated the baseline SO2 emissions by

cement kilns in 2005 by about 25 percent, this led EPA to overestimate the projected 

SO2-related monetized benefits by a similar 25 percent. The commenter can provide more 

up-to-date data to EPA.

Response: We did collect additional information to supplement what was available in the NEI, 

and we conducted quality control and quality assurance audits on these data. EPA believes this 

is a reasonable estimate of SO2 reductions. SO2 emissions from cement kilns are the product of 

sulfur in the fuel as well as sulfur in the feed materials. SO2 emission intensities (lb/ton clinker) were 

calculated for each kiln type in each cement market using the SO2 emission data in the National 

Emission Inventory (NEI). SO2 emission intensities by kiln type in each cement market were used to 

calculate national SO2 emissions in the traditional engineering analysis as well as in the ISIS model. 

The detailed methodology used calculate SO2 emission intensities is documented in memorandum 

from Staudt, Andover Technology Partners, to Srivastava, Torres, Barnett, US EPA, “RE: NOx, 

SO2 and CO2 emissions from Cement Kilns (Emissions Memo),” September 23 ,2008.

Comment: One commenter (2845) stated that EPA assumed or estimated an unrealistically high 

95 percent SO2 removal efficiency for all limestone wet scrubbers (LWS) without regard to the 

reason for the scrubber (i.e., HCl control vs. protecting an RTO) and without regard to the inlet 

concentration of SO2. According to the commenter, scrubber manufacturers indicate that 15 ppm 

is the lowest SO2 outlet concentration consistently achievable by wet scrubbers designed for SO2

capture at cement kilns. The commenter estimated a lower removal efficiency assuming the 

lowest achievable outlet concentration of 15ppm.
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Commenter 2845 provided an MS Excel workbook showing the calculations as part of their 

comment. The commenter projected that the proposed NESHAP would result in 82 percent of all 

kilns needing to install scrubbers. Since it is not known which specific kilns will need scrubbers, 

the projected control efficiencies would need to be reduced by in order to estimate the percentage 

reduction in SO2 that will likely be achieved in practice, in contrast to the potential percentage 

reduction that would occur if all kilns installed scrubbers. 

The commenter stated that it is not clear that the wet scrubbers installed at cement kilns to meet 

the proposed NESHAP requirements–either to control HCl or to protect an RTO installed to 

control THC–will achieve the performance that is expected of scrubbers intended to address SO2. 

The industry has no experience with wet scrubbers intended specifically to control HCl to very

low levels and very little experience with scrubbers intended to protect an RTO. Scrubbers 

designed specifically for HCl control would scrub using Sodium Hydroxide (NaOH) and may

not be suitable for scrubbers aimed at removing low concentrations of HCl from flue gas that has 

a high SO2 concentration. SO2 scrubbers in cement industry generally use limestone as a 

scrubbing medium (lower-cost than NaOH, results in recoverable gypsum and little in the way of 

solid waste disposal cost). It is not known how a scrubber would best be designed for removal of 

low concentrations of HCl in the presence of high SO2 concentrations, or whether the SO2

removal performance of such an HCl-optimized scrubber would differ significantly from the 

typical performance of SO2-optimized scrubbers.

Response: EPA has updated the SO2 removal efficiency of limestone wet scrubbers (LWS) to 

90%. The NSPS adopted concurrently contains a 90% removal efficiency alternative standard for 

SO2 based on use of a limestone wet scrubber, and this alternative garnered significant industry

support in the public comments. Consequently, EPA considers a 90% removal efficiency to be a 

reasonable estimate in assessing reductions of SO2 in the NESHAP as well. We also disagree 

with the statement that wet scrubber optimized to control SO2 will not control HCl to the low 

levels required by the rule. Because HCl is more reactive than SO2, we would expect that a 

scrubber optimized for 90 percent SO2 control would achieve even a higher level of control for 

HCl. In fact, data collected from municipal solid waste incinerators confirms that spray dryers (a 

similar SO2 control technology) remove HCl at levels higher then those for SO2, and achieves 

level of 90 percent more even when SO2 removal levels are in the 30 percent range.

Comment: One commenter (2845) stated that using scrubbers to control acid gas emissions from 

kilns with already low concentration of SO2 are not cost-effective for the following reasons:

 A majority of the monetized benefits that EPA estimates for the entire proposed 

regulation derive from co-control of SO2 by kilns that are projected to install scrubbers to 

meet the proposed HCl standard.

 The SO2 co-benefits from controlling HCl cannot provide a valid reason for HCl control 

requirements unless controlling SO2 itself is shown to be cost-effective.

 Emission control using LWS is not cost-effective for the cement kilns that already have 

low concentrations of SO2 because, the commenter estimated, it would cost more than 

$36,000 per ton of SO2, which is far above a reasonable figure of cost-effectiveness for 

SO2 control. The commenter provided cost and emissions reduction figures from a BACT 

analysis for a single kiln as support.
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Response: In the analysis of this rulemaking SO2 emission reductions are co-benefits of HCl 

reductions. HCl is a hazardous air pollutant regulated under section 112 of CAA. As noted in the 

preamble of the final rule we are required to set limits for HAP based on maximum achievable 

control technology. That is the reason for apply HCl controls. We do note that SO2 co-benefits 

are achieved, and are very significant. It is not necessary that we justify the cost of these SO2 cobenefits (and indeed, since they result from floor standard, EPA is precluded from considering 

costs).

For these rules the SO2 reductions represent a large fraction of the total benefits from reducing 

PM2.5 , but it is not possible to isolate the portion if the total benefits attributable to the emission 

reductions of SO2 resulting from the application of HCl controls. 

Comment: One commenter (2844) stated that there are challenges and uncertainties in meeting 

the new limits including the following:

 Facilities face extensive control investments because the limits are low and the controls 

methods are largely undemonstrated in kiln applications. 

 Activated carbon injection (ACI) and scrubber performance is dependent on having 

oxidized mercury to treat. The commenter does not know the distribution of their plants’ 

elemental and oxidized mercury emissions. 

 The proposed standards are cost-ineffective in dollars per ton of reduced emissions and 

the risk that even those significant, costly investments will not assure compliance.

 Response: EPA acknowledges that there are challenges and uncertainties in attaining 

compliance with new limits under any MACT standard. See the preamble and cost and 

environmental impacts documents for discussion of control costs and estimates of cost 

effectiveness.

Benefits Analysis

Comment: One commenter (2845) stated that EPA does not estimate the benefits from control 

of the HAP whose emissions would be reduced by the proposed NESHAP. Instead, EPA 

estimates the monetized benefits associated with co-control of the criteria pollutants, PM2.5 and 

SO2 (a PM2.5 precursor). The commenter stated that EPA performed no dispersion modeling, 

exposure assessment or risk analysis for cement plant emissions. Instead, EPA relied on the 

benefit per ton estimates developed in previous RIA. The benefits per ton figure that EPA 

accesses and uses for SO2 for the NESHAP benefits analysis reflect work done in previous RIA 

(see EPA’s Regulatory Impact Analyses (RIA) for the PM2.5 National Ambient Air Quality 

Standards (NAAQS)) to quantify the relationships between SO2 emissions, sulfates, and eventual 

PM2.5 concentrations attributable to SO2.

One commenter (2845) stated that EPA should not use PM2.5 reductions that are not required by 

the rule to justify the cost of the rule for the following reasons:

 Even though the proposed rule was developed to regulate HAP emissions, EPA estimates 

that most of the benefits, specifically the monetized benefits, will come from reducing 

PM2.5.
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 Actions taken to reduce HAP emissions will not reduce emissions of PM2.5 and PM2.5 

precursors to the extent that EPA has projected. It is improper for EPA to take credit for 

PM2.5 benefits that may not be achieved and that have not been realistically analyzed. 

EPA should quantify the benefits of HAP reductions to compare to the costs of the rule.

 EPA estimated that the annualized domestic social cost of this regulation is $694million 

and concedes that it does not have sufficient information to estimate benefits from 

reductions in emissions of mercury, HCl, or coarse PM (total hydrocarbons are not 

mentioned at all). Nor does EPA discuss the qualitative measures of these benefits, which 

must be considered essential to consider per Executive Order 12866. It is not possible to 

justify the cost of the potential reductions in the four HAPs without discussion of the 

benefit of the proposed reductions.

 EPA’s discussion of the secondary benefits does not remedy this defect in the costbenefit analysis. Such regulatory intent is contrary to the CAA State Implementation 

process. States may mandate PM2.5 controls and allocate PM2.5 emissions based on unique 

local considerations or legislative prerogatives, so long as the national standards are met. 

States have virtually absolute power in allocating emission limitations so long as the 

national standards are met and so long as the national standards are met, the 

implementing state may select whatever mix of control devices it desires. By setting 

MACT standards for the reduction of PM2.5, EPA is usurping the role of the States under 

the CAA’s NAAQS program. 

Response: As explained in the discussion of EPA’s decision to adopt a MACT standard for HCl, 

Congress was aware that there would be co-benefits from controls on air toxics in the form of cocontrol of criteria pollutants, and Congress viewed these co-benefits as a positive part of the air 

toxics control effort. It would be ironic indeed if EPA were precluded from considering these 

very real benefits in those instances where it is making discretionary choices under section 112 

(d), notably in determining in whether to set a technology-based or risk-based standard for HAPs 

with a threshold. Nor does EPA view consideration of these co-benefits as somehow 

undermining the SIP process. Indeed, States are customarily eager for federal controls of criteria 

pollutants since otherwise States must adopt localized controls to attain air quality standards. See 

e.g., 75 FR at 35570-71 (June 22 , 2010) (noting importance of forthcoming MACT rules in 

helping areas attain primary SO2 NAAQS). In addition:

 Data, resource, and methodological limitations prevented EPA from estimating the 

monetized benefits from reducing HAP emissions. For the final rule, EPA provided 

qualitative descriptions of the health effects associated with the top HAP emissions from 

cement kilns. In addition, EPA provided maps of the modeled reduction in mercury

deposition from cement kilns. Despite our inability to provide monetized benefits of HAP 

emission reductions, the total monetized benefits exceed the estimated costs of the rule by 

a substantial margin, even when taking uncertainty into account.

 The goal of an RIA is to provide a comprehensive estimate of the anticipated costs and

benefits associated with a regulatory action. Co-benefits that occur as a result of a 

regulatory action are appropriate to include in the RIA, and it is appropriate to compare 

the total monetized benefits with the costs. In many instances, it is not possible to 

quantify and monetize all of the benefits associated with a regulatory action. An RIA is 
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not prepared to justify the costs of an action, but only to estimate what the likely impacts 

would be.

 The PM2.5 emission reductions that would occur as co-benefits of this rule do not affect 

the States’ roles and responsibilities under the NAAQS program. These emission 

reductions would occur regardless of an area’s attainment status under the NAAQS, but 

these emission reductions might help those areas that are in non-attainment to reach 

attainment. This is a positive feature of the rule, not a negative.

Comment: One commenter (2890) stated that EPA must consistently evaluate positive and 

negative impacts of a rule. The commenter’s specific points were:

 EPA cannot monetize the benefits of PM2.5 (or any other pollutant) reductions to justify

action at the floor. As EPA has repeatedly claimed, the floor level of control shall not 

consider costs. If you cannot consider costs to industry in assessing whether a floor is 

reasonable, you also cannot use benefits (monetized or otherwise) from other pollutants 

in establishing the floor. The floor must stand on its own and follow the requirements of 

the Clean Air Act.

 EPA cannot monetize the benefits of PM2.5 and ignore the monetized detriments that 

would result from the controls. The EPA monetizes the benefits of PM2.5 control but does 

not monetize the detrimental impacts of the energy and other secondary emissions that 

are included in the secondary impacts section. This is arbitrary and creates an unfair 

depiction of the true impacts of this rule.

Response: The costs and the benefits presented in the RIA do not influence the MACT floor 

determination. Consideration of cost (positive or negative) is absolutely prohibited at the MACT 

floor, and EPA necessarily did not consider cost or benefit information in developing the floors.

The floors reflect the average performance of the best 12 % of existing sources, and the 

performance of the single best controlled similar source (for which EPA has emission data), as 

required by law. EPA did consider cost information, as well as non-air quality impacts and 

energy considerations, in determining not to adopt standard more stringent than the floor. The 

RIA describes impacts to energy in the RIA in section 3.5 and the energy disbenefits in section 

6.4.

Comment: One commenter (2845) stated that methodological limitations should not prevent 

EPA from estimating the monetized benefits of HAP emission reductions from the proposed rule. 

Techniques exist for conducting multipathway risk assessments for cement kilns for HAP 

emissions that EPA and industry have applied many times. For example, EPA’s worst case 

screening analysis concludes that an HCl emissions limit of 23 ppmv would result in no health 

risk to surrounding populations from current cement kiln emissions. In addition to risk modeling 

for HAP, well-accepted methods for estimating the monetary value of changes in HAP risks also 

exist and have been applied. Executive Order (EO) 12866 requires that EPA must conduct full 

analysis of benefits and costs (monetized to the extent possible) for any economically significant 

regulations. EPA must analyze the benefits from HAP emissions reductions as well as criteria 

pollutant emission reductions. According to the commenter, analysis of the benefits of the 

proposed NESHAP will likely show small to near-zero benefits from the reductions in HAP 

emissions. It is believed that hazardous waste-burning cement kilns will provide a worst case 
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representation for cement kilns and HAP risks associated with the industry will generally be less 

than or equal to those from other hazardous waste-burning kilns.

Response: Data, resource, and methodological limitations prevented EPA from estimating the 

monetized benefits from reducing HAPs emissions. For the final rule, EPA provided qualitative 

descriptions of the health effects associated with the top HAP emissions from cement kilns. In 

addition, EPA provided maps of the modeled reduction in mercury deposition from cement kilns.

Despite our inability to provide monetized benefits of HAP emission reductions, the total 

monetized benefits exceed the estimated costs of the rule by a substantial margin, even when 

taking uncertainty into account.

Comment: One commenter (2845) stated that EPA’s benefits analysis incorrectly assumes that 

exposure to and risk from fine particle and precursor emissions from the portland cement plant 

emissions is similar on average to exposure and risk from fine particle and precursor emissions 

from all other point sources. The commenter stated that cement kiln emissions are likely to cause 

less exposure on average and are less potent. For both SO2 and directly emitted PM2.5, EPA takes 

value-per-ton benefits estimates for nationwide aggregates of these pollutants that were 

developed in the Ozone NAAQS RIA and applies these values specifically to the quantities of 

cement plant emissions that will be controlled by the NESHAP. This represents an instance of 

what economists term benefits transfer; taking a benefit estimate developed in one context and 

applying it in another. Commenter 2845 stated that these situations are not similar and that the 

benefits transfers are not appropriate, for reasons having to do with both exposure and potency. 

In support of their comment, the commenter provided analyses of exposure and potency as 

factors affecting benefits.

Response: For the final RIA, EPA used the CAMx model to better reflect the geographic 

distribution of the emission reductions from cement kilns on ambient PM2.5 concentrations, 

which provides a superior representation compared to the national average benefit-per-ton 

estimate. 

The benefits models assume that all fine particles, regardless of their chemical composition, are 

equally potent in causing premature mortality because there is no clear scientific evidence that 

would support the development of different effects estimates by particle type. The recently 

released Integrated Science Assessment for Particulate Matter concluded that “many constituents 

of PM can be linked with differing health effects, but the evidence is not yet sufficient to allow 

differentiation of those constituents or sources that are more closely related to specific health 

outcomes.” In addition, the Health Effects Subcommittee of the Science Advisory Board recently

stated that “ the evidence at this time does not currently support this sort of [differential toxicity] 

assessment” (EPA-SAB-COUNCIL- 10-001).

Comment: One commenter (2845) stated that EPA made two other smaller changes in adapting 

previous benefit-per-ton values for application to the cement NESHAP; however, did not give a 

detailed explanation of what the changes were so that the public could assess them. 

Response: EPA concurs that the two technical changes were not sufficiently described in the 

proposal RIA. However, this language was removed because benefit-per-ton estimates were not 

used as the basis of the benefits estimates for the final RIA.
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In addition to the changes described in the Portland Cement NESHAP proposal RIA, EPA’s 

Office of Air and Radiation has also recently revised the value of a statistical life (VSL) used to 

calculate the human health benefits of avoided premature mortality. The final RIA contains a 

detailed explanation of this revision.

Comment: One commenter (2845) stated that the various comments provided regarding EPA’s 

benefits analysis would sum to a significant reduction in EPA’s calculated values perhaps down 

to near the level of costs that industry is estimating.

Response: EPA has reassessed the monetized benefits and costs for the final rule, including the 

energy disbenefits. For the final rule, the monetized benefits still outweigh the costs by a 

substantial margin, even when taking uncertainties into consideration.

Small business impacts

Comment: One commenter (2887) stated that the final rule should minimize impacts on small 

business. The Regulatory Flexibility Act (RFA), as amended by the Small Business Regulatory

Enforcement Fairness Act (SBREFA), 5 U.S.C. §601 et seq., imposes procedural requirements 

on EPA that must be followed in promulgating a rule. The commenter requested that the EPA 

minimize the economic impact of the final Portland Cement NESHAP on small entities. EPA’s 

analysis of the economic impact of the proposed rule on small business cement plants suggested 

that the highest single impact based on a cost-to-sales ratio is on a small entity. 

The commenter respectfully disagrees that the EPA minimized the impact on small entities in the 

proposed rule. Small entities are subject to the same MACT floor standards as larger businesses. 

To the extent that the rule includes any provision that minimizes the impact on small entities as 

compared to large businesses, the commenter requests that the EPA specifically identify those 

provisions and explain the difference in economic impact between small businesses and larger 

companies. More importantly, the commenter does not agree that the MACT floor is the least 

stringent level allowed by law.

Response: To the extent the commenter suggests that EPA should have altered the floor 

methodology to accommodate small businesses, the comment is misplaced because the 

requirements for MACT floors are non-discretionary and dictated by statute. EPA is also 

certifying that the final rule does not have a significant impact on a substantial number of small 

businesses.

We estimate that 3 of the 26 existing Portland cement entities are small entities and will not incur 

any impacts under the final amendments for NSPS subpart F unless an affected facility is 

constructed, modified, or reconstructed. Although this final NSPS will not have a significant 

economic impact on a substantial number of small entities, EPA nonetheless has tried to reduce 

the impact of this rule on small entities by the selection of an emission level based on highly 

cost-effective controls and specifying monitoring requirements that are the minimum to ensure 

compliance. In the case where there are overlapping standards between this NSPS and the 

Portland Cement NESHAP, we have exempted sources from the least stringent requirement 

thereby eliminated overlapping monitoring, testing and reporting requirements by requiring that 

the source comply with only the more stringent of the standards.
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For subpart LLL (NESHAP), EPA performed a screening analysis for impacts on the three 

affected small entities by comparing compliance costs to entity revenues. EPA’s analysis found 

that the ratio of compliance cost to company revenue for one small entity (a tribal government) 

will have an annualized cost of less than 1 percent of sales. The other two small businesses will 

have an annualized cost of between 1 and three percent of sales. Although this final NESHAP 

will not impact a substantial number of small entities, EPA nonetheless has tried to reduce the 

impact of this proposed rule on small entities by setting the final emissions limits at the MACT 

floor, the least stringent level allowed by law. In the case where there are overlapping standards 

between this NESHAP and the Portland Cement NSPS, we have exempted sources from the least 

stringent requirement thereby eliminating the overlapping monitoring, testing and reporting 

requirements by requiring that the source comply with only the more stringent of the standards.

In addition, we applied MACT for HCl emissions to major sources only. The reduced 

compliance costs for two of the three small entities by a factor of 4.

More discussion is provided in the preamble.

Comment: In extrapolating from available data, one commenter (2845) asked if EPA has 

applied the correct basis for factors, such as using the correct percentage of raw mill on versus 

raw mill off when applying the emission rate to additional facilities (can affect mercury, HCl, 

and SO2)? Have operational considerations across the various kiln types been taken into account?

Response: When appropriate, EPA did take into consideration the effects of the process on 

emission rates. For example, in identifying the top performing kilns for PM emissions, we 

recognized that PM emissions were generally higher during raw mill off conditions compared to 

raw mill on. As a result, we calculated a weighted average PM emission level for kilns with raw 

mills where we had test data for both raw mill on and off conditions. When we collected 

additional HCl data, we specified that for kilns with raw mill, HCl testing was to be done with 

the raw mill on and off. The mercury emissions limit w as based on 30-days of raw material 

sampling and analysis for mercury content so that the raw mill status was not an issue. Also, the 

THC limit was based on long-term (hundreds of days) CEM data which would account for the 

raw mill. In addition, all of the compliance periods are set as 30 day averages which allow for the 

changes in the raw mill operations. 

2.12 Environmental Justice

Comment: One commenter (2786) stated that mercury pollution more significantly impacts poor 

and minority populations, and EPA should regulate mercury emissions from the portland cement 

industry to the greatest extent possible because of their adverse health impacts on poor and 

minority communities. Executive Order 12898 states that to the extent practicable and permitted 

by law, each federal agency shall make achieving environmental justice part of its mission by 

identifying and addressing, as appropriate, the disproportionately high and adverse human 

health or environmental effects of its programs, policies, and activities on minority populations 

and low-income populations in the United States. The commenter stated that EPA has 

historically devoted little attention to evaluate the impact of decisions made under the Clean Air 

Act on low-income and minority communities. The commenter provided discussion about 

pathways for human ingestion of mercury and how poor and racial minority group are exposed to 

higher levels of mercury through their livelihood and culture. In addition to the impact of 
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mercury on poor and minority communities, the commenter also listed the following HAPs as 

matters of potential regulation: lead, chromium, arsenic, and beryllium.

Response: See discussion of Environmental Justice in Section VII of the preamble to the final 

rule.

Comment: One commenter (2863) stated that the proposed rule has serious environmental 

justice issues. 

The first issue is that two plants are likely to have to close as a result of the rule. The populations 

around these plants rely heavily on the plants for income. The commenter conducted a 

comprehensive risk assessment showing that the mercury emissions do not result in unacceptable 

risks even before controls. The adverse impact of closure would be to the health of the families 

who depend on this facility for income and health insurance, with no commensurate 

improvement related to the reduced emissions associated with closure as the plant will be well 

under the acceptable risk thresholds when the controls currently being constructed are 

operational.

Closure of the two plants will mean that more cement will be imported from overseas. As Asia 

and India dominate imports to the west coast, the gap left by California and Oregon plant 

closures will almost certainly occur in nations with far less stringent controls and significantly

higher direct and indirect emissions of criteria pollutants, HAPs and greenhouse gases. This is 

particularly relevant in relation to mercury and greenhouse gases as these are the most obviously

global pollutants. However, moving production offshore will also result in localized impacts and 

so will disproportionately impact impoverished areas.

Response: In this final rule, we are not projecting any facility closures. To assess whether this 

rule's environmental and health impacts would have a disproportionate effect on vulnerable 

populations, EPA looked at demographic data in aggregate for census block groups in near 

proximity to cement facilities. EPA analysis showed that within the radii examined (0.5 mi, 3 mi, 

and 5 mi from sources subject to this rule), the percentages of minority and low income 

populations were similar to national averages. EPA's demographic analysis can be found in the 

docket for this rulemaking.

In addition, as stated in the final rule preamble, EPA is reaching out to the two high mercury

limestone quarry sources to investigate the possibilities of early aggressive reductions of mercury 

emissions with a negotiated longer compliance period.

Comment: One commenter (2898) stated that EPA has failed to undertake an actual analysis of 

the consequences of the rule on environmental justice populations. The commenter stated that 

EPA should undertake a more thorough analysis of the risks posed by the cement industry and 

the benefits of more stringent standards.

Response: EPA analyzed each standard to determine if beyond the floor control was warranted, 

and concluded that further controls were not warranted due to high cost, poor cost effectiveness, 

non-air quality impacts in the form of waste generation and water usage, and increased energy 

use. Nothing in this comment undermines those conclusions. EPA does note that it took two 

significant discretionary decisions in the rule – adopting a MACT standard for HCl and not 
210

subcategorizing for two high mercury emitting sources – which result in very significant 

reductions of acid gases, secondary fine PM, and mercury.

Comment: One commenter (2908) stated that the proposed rule may constrict cement supply

and increase pressures on the availability of affordable housing. 

Response: In this final rule, we are not projecting any facility closures. To assess whether this 

rule's environmental and health impacts would have a disproportionate effect on vulnerable 

populations, EPA looked at demographic data in aggregate for census block groups in near 

proximity to cement facilities. EPA analysis showed that within the radii examined (0.5 mi, 3 mi, 

and 5 mi from sources subject to this rule), the percentages of minority and low income 

populations were similar to national averages. EPA's demographic analysis can be found in the 

docket for this rulemaking.

Comment: One commenter (3222) stated that the commenter’s local cement plant creates 

environmental and social justice problems.

Response: In this final rule, we are not projecting any facility closures. To assess whether this 

rule's environmental and health impacts would have a disproportionate effect on vulnerable 

populations, EPA looked at demographic data in aggregate for census block groups in near 

proximity to cement facilities. EPA analysis showed that within the radii examined (0.5 mi, 3 mi, 

and 5 mi from sources subject to this rule), the percentages of minority and low income 

populations were similar to national averages. EPA's demographic analysis can be found in the 

docket for this rulemaking.

2.13 Open Clinker Piles

Comment: Several commenters (2845, 2864, and 2874) stated that in the past, EPA considered 

regulating open storage piles; however, in the 2001 settlement agreement and subsequent followup letter from EPA to American Portland Cement Alliance that settled litigation over the 1999 

NESHAP final rule, EPA agreed not to regulate fugitive emissions from open or unenclosed 

material stockpiles or haul roads. Although, the proposal asserts that open clinker storage piles 

located at two facilities had measurable emissions of hexavalent chromium, the emissions and 

the ambient concentrations in the area surrounding cement facilities were low. The ambient 

concentrations are also miniscule when compared to benchmark regulatory standards. Also, 

several California air quality district have decided against regulating hexavalent chromium 

emissions from cement plants due to the lack of risk. For these reasons, it would be inappropriate 

to define open clicker storage piles as affected sources under the NESHAP.

Response: At proposal we noted that open clinker piles were currently unregulated, and that 

hexavalent chromium emissions had been detected in fugitive dust from these piles. See 74 FR at 

21163. We requested comment and information as to how common the practice of open clinker 

storage is, appropriate ways to detect or measure fugitive emissions (ranging from open-path 

techniques to continuous digital or intermittent manual visible emissions techniques), any 

measurements of emissions of hexavalent chromium (or other HAP) from these open storage 

piles, potential controls to reduce emissions, or any other factors we should consider.
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Commenters did not provide data on this practice. Industry commenters stated emissions were de 

minimis and should not be regulated. Other commenters noted that the fact that we know these 

sources emit HAP is sufficient to necessitate regulation.

We agree that these operations do emit HAP and that regulation of these sources is necessary.

See National Lime, 233 F. 3d at 640 (upholding EPA position that de minimis exceptions are not 

to be read into the MACT standard setting process). Because the emissions in question are 

fugitive dust for which measurement is not feasible since (by definition) the emissions are not 

emitted through a conveyance or other device which allows their measurement (see section 112 

(h) (1) and (2)(A)), we are incorporating the work practice standards and opacity emissions 

limits contained in Rule 1156 as amended by the South Coast Air Quality Management District 

on March 6, 2009 and incorporating them into this rule. There are only two plants which EPA 

can state definitively have open storage piles and are complying with Rule 1156, so these 

existing regulatory standards would constitute a floor level of control (and EPA does not believe 

beyond-the-floor controls are needed, since utilizing some type of enclosure should well control 

fugitive emissions).

Industry commenters also maintained that regulation of open storage piles would violate a 2001 

settlement agreement between EPA and the industry in which EPA agreed that the 1999 rule did 

not apply to fugitive emission sources. But nothing in that settlement agreement prevents EPA 

from amending its regulations if it is appropriate to do so (nor could EPA legally bind itself in 

such a way). The agreement in fact states that “[n]othing in this Agreement shall be construed to 

limit or modify EPA's discretion to alter, amend, or revise, or to promulgate regulations that 

supersede, the regulations identified in section III of this Agreement.” Consequently, EPA’s 

action today amends the current regulation, and does not violate any provisions of the settlement 

agreement. 

See the preamble discussion for more information on EPA’s decision.

Comment: Several commenters (2144, 2816, 2898, 2911, and 2913) supported EPA’s efforts to 

investigate and address the effects of hexavalent chromium from clinker storage. 

Response: EPA acknowledges the commenter’s support.

Comment: Several commenters (2816, 2911, and 3162) agreed that open clinker piles should be 

included in the regulation. Commenter 2816 noted that the Agency is already regulating enclosed 

clinker piles, and the Agency has noted measurable emissions of hexavalent chromium due to 

fugitive emissions. The commenter stated that while it may be more difficult to control fugitive 

emissions, it does not relieve either the industry or the Agency from reducing to the maximum 

degree feasible emissions from this source. Commenters 2816 and 3162 recommended that EPA 

should review the rules adopted by the South Coast Air Quality Management District and 

consider adopting similar requirements for open clinker piles.

Response: EPA has adopted this approach in the final rule.

Comment: One commenter (2864) stated that EPA should set work practice standards in the 

event that EPA is compelled to regulate open clinker piles.
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Response: EPA has done so in the final rule.

Comment: One commenter (2898) stated that the rule should cover all emissions of hexavalent 

chromium from a cement manufacturing facility that constitutes a major source, including 

emissions from storage units, conveying system transfer points, and fugitive emissions, including 

those from open clinker piles. 

Response: The final rule includes provisions for clinker piles. See preamble for more discussion.

2.14 Crushing Operations

Comment: Several commenters (2845 and 2874) stated that the 2001 settlement agreement that 

settled litigation over the 1999 NESHAP final rule specified that the final rule should not apply 

to primary and secondary crushing operations located at portland cement plants with 

nonmetallic mineral processing operations. On April 05, 2002, EPA amended §63.1240(c) to 

implement the language from the 2001 settlement agreement. However, with no discussion in the 

preamble, the proposed revision to §63.1240(c) would delete language concerning equipment of 

the on-site nonmetallic mineral processing plant that precedes the raw material storage not being 

subject to the NESHAP. The proposed rule only leaves language stating that crushers are not 

covered by this subpart regardless of their location without any explanation given in the 

preamble. Commenter 2845 opposed the proposed breach of the 2001 settlement agreement 

negotiated 7 years ago. The rule would become unclear as to whether subpart LLL of the 

NESHAP would apply to quarry sources such as conveyance systems and exterior stockpiles 

associated with crusher systems. There was no reason to eliminate the certainty of the current 

language in §63.1340(c) which will only add to confusion and needless applicability of the 

NESHAP to sources already regulated under subpart OOO NSPS; thus, EPA should not amend 

§63.1340(c). Commenter 2845 also stated that a word has been left out of the proposal preamble 

language discussing §63.1340(c) where it states that crushers were part of the affected source for 

this rule instead of crushers were NOT part of the affected source for this rule. Thus, there 

appeared to be a conflict with the current proposal, the current preamble, and also the current 

preamble language is inconsistent with the 2006 portland cement final rule. The commenters 

requested EPA to clarify in the final rule that crushers were never covered by the NESHAP and 

should also retain the existing language for §63.1340(c).

Response: We have not made the change requested by the commenters. See the preamble to this 

final rule. The reason for this change was explained in the proposed 2005 rule and final 2006 rule 

(Cite to 70 FR 72341-42 and 71 FR 76532).

2.15 Coal Mills

Comment: Several commenters (2845 and 2910) stated that portland cement plants grind their 

coal using a stand-alone coal mill or in-line coal mill and utilize two configurations of an inline 

coal mill. The first is where air pollution control devices from the inline coal vent directly to the 

atmosphere and the second configuration is where exhaust gases from the inline coal mill are 

directed back to the main kiln stack, where they are commingled with the kiln emissions. The 

commenter argued that stand-alone coal mills that vent directly to the atmosphere should remain 

regulated under Subpart Y whereas stand alone and inline coal mills where the gases vent out the 
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main kiln stack should be regulated by the NESHAP. When inline coal mill gases are vented 

through the main kiln stack, more THC emissions will exist than if there were no commingling 

of kiln and coal mill exhaust gases. Thus, establishing a subcategory for this particular 

configuration may be appropriate and the commenter proposed that additional THC testing be 

conducted in order to examine possible subcategorization for THC.

Response: EPA did consider subcategories based on coal grinding configurations as suggested 

by the commenter but decided against creating separate subcategories. See the preamble 

discussion under the THC limits for more information on EPA’s decision.

Comment: Several commenters (2845 and 2864) stated that since coal mills operate with a blend 

of kiln gases and ambient air, the concentration of pollutants exiting the coal mill would not be 

expected to be higher than the concentration exiting the kiln. In addition, coal mills are generally 

equipped with some sort of temperature alarm or indicator to avoid safety hazards related to the 

explosion potential of coal dust. If the temperature of the gases leaving the coal mill is below the 

temperature at which pollutants are formed, the concentration leaving the coal mill would not 

exceed the concentration exiting the kiln and thus performance testing and pollutant monitoring 

for coal mills should not be necessary. The commenter suggests that language be added to the 

rule specifying that although no in-line coal mills are covered by subpart 63.1340(e), they must 

adhere to the standards in 40 CFR part 60 subpart Y, as applicable. In-line coal mills with 

exhaust that is commingled with kiln exhaust are covered by this subpart, exempt from 

subpart Y, and are exempt from monitoring and testing under this subpart.

Response: If a coal mill is heated with kiln exhaust, it is subject to all the emissions limits, and 

associated monitoring, reporting, and recordkeeping requirements of this subpart.

Comment: One commenter (2863) stated that EPA should clarify that indirect fired, in-line coal 

mills need not employ mercury or HCl CEMs or separately demonstrate compliance if they vent 

through a separate stack. Indirect fired in-line coal mills receive their sole source of air and heat 

from the associated kiln (or in some cases, the clinker cooler). Therefore, consistent with 

numerous EPA opinions, these units are subject to the kiln exhaust standards. The proposal 

requires that affected sources install and operate either a mercury CEM or sorbent trap-based 

integrated monitor. There is no basis for concluding that the drying of coal will increase the 

mercury or HCl concentration in the kiln exhaust that is vented through the coal mill. In order to 

avoid explosion hazard, indirect fired, in-line coal mills must be maintained at temperatures 

below 200°F at all times and so the temperature is too low to volatilize the mercury in the coal.

Response: We have not covered coal mills with separate stacks. They are not listed as an 

affected source, so there is no need to mention them in the rule. They were not originally covered 

in this subpart and are not covered in the final rule.

If a coal mill is heated with kiln exhaust, it is subject to all the emissions limits, and all 

associated monitoring, reporting, and recordkeeping requirements of this subpart.
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2.16 Compliance Assurance

Support for CEMS

Comment: Several commenters (2144, 2622, 2828, 2895, and 2911) supported the provision for 

CEMS for portland cement kilns.

Response: We appreciate the commenters’ support.

2.16.1 Flow Rate Monitoring

Comment: One commenter (2845) stated that EPA has not developed and promulgated 

appropriate performance specifications for effluent flow rate monitors in 40 CFR 60 or 63. PS-6 

is inappropriate for use with either PM CEMS certified under PS-11 and/or mercury CEMS 

certified under PS-12A or mercury sorbent trap monitoring systems certified under PS-12B. 

Appropriate performance specifications and quality assurance procedures should be developed 

for the proposed monitoring applications in Subpart LLL.

Response: Part 75 contains flow rate specifications which are now referenced on this rule.

2.16.2 Kiln Feed/Clinker Production

Comment: One commenter (2845) stated §63.1349(b)(1)(vi) requires continuous measurement 

of kiln feed rate and clinker production during the initial performance test for sources that use 

PM CEMS which is unnecessary and should be changed. In addition to the PM concentration 

measured by the PM CEMS, the effluent flow rate and clinker production rate are needed to 

determine emissions in units of the standard (lb/ton clinker produced). The measurement of both 

clinker production rate and kiln feed rate are redundant. Measurement of one or the other process 

parameter should be required, but not both.

Response: We have modified the rule language to make it clear that separate direct 

measurements for kiln and clinker production are not required. A facility always has the option 

of calculating clinker production from the feed rate and their site specific clinker to feed ratio..

Comment: One commenter (2845) stated that if an area source directly monitors clinker output 

and emission limits are expressed as mass of pollutant per ton of clinker produced, kiln feed does 

not need to be recorded. If final standards are expressed as mass of pollutant per ton of kiln feed, 

clinker production does not need to be recorded. Keeping records of both parameters (daily 

clinker production rates and kiln feed rates) as required by §63.1349(b)(3)(iii) is redundant.

Response: The emission limits for mercury and PM are based on clinker production. Limits for 

HCl and THC are concentration-based. Most facilities record kiln feed rates and apply a 

conversion to get clinker production. If kiln feed is measured, records of the kiln feed and the 

conversion factors should be kept. If clinker production is measured, there is no need to keep 

records of kiln feed rates.

Comment: One commenter (2845) stated that very few cement plants in the United States 

physically weigh clinker as it is produced. Those that do weigh clinker are typically the newer 
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precalciner kilns systems. In older existing kilns, maintenance and calibration are difficult. Due 

to the nature of the kiln process, at least on a short-term basis, clinker output from the kiln will 

fluctuate while the kiln feed rate remains constant. For those kilns that do continuously weigh 

clinker, the ±5% accuracy requirement is not achievable for an hourly averaging period, as is 

suggested in the proposed rule language. The ±5% accuracy is achievable on a monthly basis 

where these short-term fluctuations and upsets average out. Therefore, the commenter proposed 

that a monthly averaging period for accuracy of clinker weigh scale systems for those kilns that 

are able to employ clinker weigh scale systems.

The commenter agrees with EPA’s proposed alternative to measuring clinker, but noted that 

procedures for development of the clinker factor and verification of its accuracy need to be 

developed. The commenter recommended that a standardized procedure should be developed 

through ASTM.

The commenter provided suggested language for §63.1350(o)(1) to reflect these suggestions.

Response: See response in preamble to final rule indicating that clinker need not be weighed but 

can be estimated from the facility’s feed to clinker ratio.

Comment: Several commenters (2845 and 2874) stated that there has been confusion about the 

timeframe for the clinker weigh system. Some interpret it as 30 days from when the rule is 

promulgated (i.e., 35 months before an existing source must comply with the rule), and others 

interpret it as 30 days from the time existing facilities must comply (i.e., 3 yrs + 30 days). The 

rule needs to specify that existing facilities must comply on the compliance date for the revised 

PM or mercury Standard (whichever may occur sooner), which is three years from the effective 

date of the revised rules.

Response: For existing sources we proposed a compliance date of 3 years after the promulgation 

of the new emission limits for mercury, THC, PM, and HCl to take effect. This is the maximum 

period allowed by law. For new sources, the compliance date will be the effective date of this 

final rule or startup, whichever is later. Because this is a major rule as defined by the 

Congressional Review Act, the effective date of the rule is 60 days after publication of the 

Federal Register. Accordingly, we have selected a date that allows facilities to design and install 

the required control and other ancillary equipment (e.g., clinker weigh systems) prior to the 

compliance date.

Comment: One commenter (2874) stated that EPA should clearly state that the use of kiln feed 

monitoring does not require Administrator approval and should modify the proposed regulatory

text relating to compliance. EPA’s acknowledgement in the regulations that this alternative 

method is acceptable should act as Administrator approval and no owner or operator should need 

to request Administrator approval to utilize a methodology deemed acceptable by the 

regulations. Commenter 2874 suggested that the last proposed sentence appearing in both 40 

CFR 63.1349(b)(1)(ii) and 40 CFR 63.1350(o)(1) be revised to state that The use of a system that 

directly measures kiln feed rate and uses a conversion factor to determine the clinker production 

rate is an acceptable method and a method that does not require further Administrator approval.
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Response: Since it appears from comments that the equipment to accurately measure clinker is 

not typically installed in this industry, we must assume these facilities use a feed-to-clinker 

conversion factor to calculate clinker production on whatever time basis is necessary (e.g., daily, 

hourly, etc.). Therefore, we have modified the rule language to more clearly provide the option 

allowing facilities to measure feed inputs and to use their site specific feed/clinker ratio to 

calculate clinker production (and that no prior approval from a regulatory authority is necessary

to do so). Facilities would be allowed to use a constant feed/clinker ratio in accord with their 

usual cycles for determining such ratios, typically on a monthly basis when clinker inventories 

are reconciled.

2.16.3 Electronic Reporting

Comment: One commenter (2816) supported EPA’s decision to improve accessibility of data 

from stack tests and include monitoring information in the WebFIRE data base. The commenter 

urged EPA to make electronic data submission a requirement of this rule. An electronic database 

that is accessible to the public is an important accountability and enforcement tool. Communities 

surrounding these industrial facilities deserve to know detailed emissions data. Furthermore, as 

the EPA points out in the preamble, electronic submission of data actually reduces the burden on 

industry, and is a cost-saving measure for the Agency as well.

One commenter (2834) stated that requiring electronic submission of emissions will allow EPA 

to bypass the laborious and cumbersome process of collecting information from a variety of 

sources in a variety of formats. Given that nearly every one of the categories in which EPA has 

requested specific comments includes a request for additional data, requiring electronic 

submission of emissions tests should be required. Further, electronic submission of emissions 

results will facilitate public to access those results. Standardized, electronic reporting of 

emissions test results to EPA would facilitate the public’s access to these emissions records.

Response: Our intent is to make electronic reporting a requirement starting in 2012 when the 

system is fully capable of accepting data. The rule language has been modified to reflect this.

2.16.4 Other

Detection limit

Comment: Several commenters (2832 and 2859) argued that EPA’s proposed revision to an 

approved EPA stack testing method, specifically to promulgate a downward revision of a method 

detection limit in an approved stack testing method is arbitrary and reflects that EPA has failed to 

consult and take action based on direction from its own Emissions Measurement Center. In 

addition, EPA has failed to explain its numeric approach to the actual lower detection limit 

selected. The detection limit should be set at a level that all sources that are subject to stack 

testing requirements would be able to achieve uniformly in practice. The CAA requires that all 

stack testing detection limits take all factors that can or do influence results into consideration 

when proposing a detection limit.

Response: We have taken the appropriate steps to address the detection limit issue, including 

consulting with EPA test experts and taking comments on the detection limit in the proposal 
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notice. Data obtained to date conforms that detection limits using EPA Method 321 for HCl 

emissions measurement are 0.2 to 0.3 ppmv in the field.

Alternatives to CEMS

Comment: Several commenters (2832 and 2859) opposed the proposed requirement to install 

CEMS in order to satisfy compliance assurance monitoring (CAM) for selected pollutants. 

Instead, the commenter proposed that CAM requirements be satisfied using periodic stack testing 

to the extent that stack testing is requested or require by state air permits. According to EPA’s 

proposal, the MACT floor for new and existing sources in this industry will be determined by

stack testing results of sources within the MACT pool. If EPA were to finalize a numeric 

emissions limitation based on this approach to setting the new and existing MACT floors, that 

limitation will be based on the same stack testing data. CEMs will have played no role in this 

process. It stands to reason that compliance assurance should be based on stack testing results, 

and not a CEMs data that has played no part in this process.

One commenter (2916) stated that EPA can achieve a reasonable assurance of compliance 

without the use of CEMS. The requirement to use CEMS is unreasonably costly and 

unnecessary, given that other reliable means of showing compliance are available for all relevant 

pollutants. Raw material sampling and kiln parametric monitoring, in conjunction with periodic 

testing, would work well for THC and HCI. The sorbent trap method for mercury is a good 

alternative to mercury CEMS and should be retained in the final rule. EPA should refrain from 

requiring PM CEMS in the final rule. Bag leak detection systems and parametric monitoring of 

ESPs are proven methods for assuring ongoing compliance with PM limits.

Response: See response in preamble

Modified visible emission requirements

Comment: According to one commenter (2874), EPA has modified the visible emission 

requirements of 40 CFR 63.1350(a)(4) without adequate explanation for the proposed revisions. 

The commenter stated that EPA originally set a 1-minute standard as it was believed by the 

industry and EPA that a longer test would be unduly burdensome–especially in light of the fact 

that tests must be conducted for each affected source. Nothing has occurred during the past 

10 years that warrants a 20-fold increase in the manpower and cost required for the testing. The 

commenter suggested that EPA retain the current 1-minute testing requirement.

Response: As explained above we have changed the observation time to 10 minutes.

Clarifications

Comment: One commenter (2845) stated that §63.1349(b)(3)(iii) required that hourly average 

temperatures be calculated for each dioxin/furan performance test run which is inconsistent with 

§63.1349(b)(3)(iv) and should be corrected. The language of the existing §63.1349(b)(3)(ii) 

states that one minute average temperatures must be calculated for each minute of each run of the 

test and was replaced by language which states that hourly average temperatures must be 

calculated for each run of each test. This is inconsistent with §63.1349(b)(3)(iv) which correctly

states that the run average temperature must be calculated and the average of all runs is used to 
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determine the applicable temperature limit. This is easily corrected and clarified by re-inserting a 

slightly modified version of the original language which states that one minute average 

temperatures must be calculated and recorded for each minute of each run of the test.

Response: We agree and have made the chances suggested by the commenter.

Comment: One commenter (2832) stated that EPA needed to ensure that the regulatory rule 

analysis statements in the preamble are reflected in the regulatory text, including proposing 

specific regulatory text to make the regulation clearer and easier to implement.

Several commenters (2864 and 2874) stated that the regulations proposed at 40 CFR 63.1349(f) 

and (g) are so vague and contain numerous inappropriate cross references to other regulations 

that it impossible to provide a meaningful comment. The commenters provided several examples 

of what they considered inappropriate cross references. Commenter 2874 suggested that EPA 

withdraw the rule and perform a complete review for these types of errors, fix the errors and repropose the rule for comment.

Response: We agree that the proposed rule contained some errors, and we have made several 

corrections and clarifications to the final rule to ensure it is consistent with our stated intent in 

the preamble. These corrections and clarifications are not significant changes to the proposed 

rule, however, and reproposal is not needed. We disagree however that §63.1349(f) and (g) are 

confusing, and have retained these cross references as they are accurate and ensure consistency.

Mercury, HCl and PM CEMS not demonstrated

Comment: One commenter (2858) stated that while THC CEMS have been used by cement 

plants for years, CEMS monitors for mercury, HCl and PM have not been demonstrated to be 

reliable and sufficiently accurate to satisfy EPA’s performance specifications when operating on 

cement kilns.

Response: We disagree. Mercury CEMS have been widely applied in the utility industry and 

there are no technical reasons that would imply that do not work equally well on a cement kiln.

PM CEMS have also been demonstrated in utility boilers. Hydrochloric Acid CEMS have been 

used on source categories such as municipal waste combustors and utility boilers.

Publicly available monitoring data

Comment: Several commenters (2893 and 2895) requested that EPA make all CEMS and other 

monitoring information readily available to the public, and when produced in real time, available 

in real time on the web site. Commenter 2893 stated that mechanisms to enforce the rules need to 

have enforcement provisions that not only document agency compliance, but also make the 

agency reports readily available to the public. Where possible, emissions information should be 

posted on the EPA or Air District’s web sites in a timely manner. This request is driven by the 

commenter’s experience with inadequate responses from enforcement agencies to potentially

excessive emissions from local plants. 

Several commenters (2816 and 2928) recommended the use of CEMS as the better monitoring 

method, and suggested a specific mercury monitor suitable for use. The commenter suggested 
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that to further earn public confidence, the data should be reported every thirty days and the 

monitoring results be made available to the public online. Commenter 2816 urged EPA to adopt 

CEMS requirements for all of the pollutants for which an emission limit will be adopted.

Response: We are currently developing a reporting mechanism for CEMS data. We will 

consider these comments as we continue that effort. In concept, the CEMS data base would be 

publically available. However, the reporting frequency has not been developed.

Potential to emit to determine applicability

Comment: One commenter (3138) stated that EPA should determine whether a facility must 

comply with the standard based on their potential to emit under the worst case operating 

scenario. The commenter stated that it should make no difference if the source is an area or a 

major source. The potential to emit should be based on the facility’s permitted fuels, hours, and 

potential emissions during SSM events. The determination for compliance with the new standard 

should include the potential emissions from grace periods allowed by state regulators.

Response: Questions of how to calculate Potential to Emit are not part of this rulemaking, and 

therefore this comment is beyond the scope of this proceeding.

2.17 Other – Miscellaneous Comments

Failure to address greenhouse gases

Comment: Several commenters (2832 and 2859) opposed the approach taken by EPA in its 

beyond-the-floor MACT analysis. Among other things, EPA failed to consider the creation of 

incremental greenhouse gas emissions associated with the construction, installation and 

operation of new emissions control equipment, and the minimal incremental environmental 

benefit associated with those controls. Also, EPA failed to consider the cost of carbon credit 

purchases by the industry.

Response: See preamble for response.

Counting multiple production units in MACT pool

Comment: One commenter (2832) concurs with EPA’s approach to determining the number of 

sources that comprise the so-called MACT pool to the extent that EPA has counted multiple 

production units whose emissions are ducted to a single control device as one source. Any 

attempt to apportion emissions between or among multiple production units in the foregoing 

configuration would be arbitrary. If EPA determined to count each production unit as a separate 

source, it would be obligated to attribute for MACT purposes, all of the emissions from the 

single control device to each source because there is no scientifically demonstrable methodology

to apportion emissions. The legal consequence of EPA’s approach to determining the number of 

sources that comprise the so-called MACT pool is to establish an emission standard based on air 

emission control device removal efficiency and as required by §112. Failure to act in a manner 

consistent with the foregoing would be arbitrary.

Response: EPA acknowledges the commenter’s support.
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Clarifications

Comment: One commenter (2845) stated that the definition of clinker should include that 

clinker can be ground with either gypsum and/or other materials to form cement. Commenter 

2845 suggests the definition could be changed to read: clinker means the intermediate product of 

the process in which limestone and other raw materials are heated in the kiln and are then ground 

with gypsum and/or other materials to form cement.

Response: See the final rule for the definition of clinker.

Comment: One commenter (2845) stated that since crushers vary in the size of rock they

produce and because crushers and their associated conveying systems are already regulated 

under 40 CFR part 60 subpart OOO, the definition of a crusher should be deleted and instead add 

a definition describing a crusher system that reads as a crusher system means equipment used to 

reduce the size of large raw material for further processing and the associated material handling 

sources including, but not limited to, screens conveying systems, storage bins preceding the raw 

mill, and stockpiles or if §63.1340(c) is not changed then no definition of crusher or crusher 

system will be needed. 

Response: See the final rule for the definition of clinker.

Comment: One commenter (2845) stated that the definitions for greenfield kilns, greenfield inline kiln/raw mills, or greenfield raw material dryers and new brownfield kilns, new brownfield 

in-line/raw mills, or new brownfield raw material dryers are no longer needed because all 

references to them have been remove from the rule.

Response: The definitions identified by the commenter were removed from the final rule.

Comment: One commenter (2845) stated that a totally enclosed conveying system transfer point 

is defined within §63.1350(a)(4)(v) as a conveying system transfer point that is enclosed on all 

sides, top, and bottom. This definition should be expanded and moved to §63.1341, and should 

read: Totally enclosed conveying system transfer point means a conveying system transfer point 

that is enclosed on all sides, top, and bottom. This includes, but is not limited to, pneumatic 

transfer systems. 

Response: A definition of “totally enclosed conveying system transfer point” was added to the 

final rule.

Comment: One commenter (2845) stated that §63.1343(b)(3) and §63.1343(c)(3) should be 

clarified to state that dioxin/furan standards are on a dry basis corrected to 7 percent oxygen.

Response: The rule was clarified to state that the standards for dioxin/furan are on a dry basis at 

7 percent oxygen.

Comment: One commenter (2845) stated that an additional option should be included in 

§63.1344(a): §63.1344(a)(4) The owner or operator may choose to set one applicable 

temperature limit for the main in-line kiln/raw mill exhaust, specified in paragraph (b) of this 

section and established during the performance test when the raw mill was not operating. If the 
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owner or operator chooses this option, the limit would apply when the raw mill of the in-line 

kiln/raw mill is operating and when the raw mill is not operating. As this is a more restrictive 

limit, additional justification should not be necessary.

Response: The suggested revision was considered to be outside the scope of this rulemaking; no 

change was made.

Comment: One commenter (2845) stated that §63.1344(e) should be clarified to clearly state 

that the requirements only apply if using carbon injection specifically for dioxin/furan control.

Response: The language was clarified as suggested by the commenter.

Comment: One commenter (2845) suggested that EPA should provide an option for one 

dioxin/furan compliance limit set by using performance test when raw mill was not operating. 

This is similar to the option provided in 40 CFR 63 Subpart EEE. As it is a more restrictive limit, 

additional justification should not be necessary.

Response: EPA did not believe the suggested change was within the scope of this rulemaking.

Comment: One commenter (2845) stated that §63.1349(b)(3)(iv) should include an option for 

maintaining the temperature limit if a repeat test shows a lower value. The commenter noted that 

when conducting the repeat performance test every 30 months for dioxins/furans, the resulting 

temperature limit can often vary arbitrarily above or below the previous temperature limit (set 

during the previous performance test). If no change is operations has occurred, as described in 

40 C.F.R. 63.1349(e) as otherwise requiring the establishment of a new temperature limit, the 

facility should be allowed to maintain their current temperature limit even if a new repeat 

performance test average temperature is lower than the current limit. The 30 month test should 

be allowed to be viewed as a confirmatory type test that is demonstrating compliance with a limit 

that is not changing, rather than to continuously change the actual limit. This would be consistent 

with §63.1349(e) which requires establishing new temperature limits only when a change in 

operations occurs that would adversely affect compliance with a dioxins/furans standard. The 

commenter provided suggested language.

Response: EPA did not believe the suggested change was within the scope of this rulemaking.

Comment: One commenter (2845) stated that in §63.1349 (c) both existing and new kiln and inline kiln/raw mills are required to have CEMS for PM, THC, mercury, and HCl. This rule 

appears to indicate that none of the performance testing requirements in §63.1349 apply. If this is 

indeed the correct interpretation, it should be made clearer in the individual sections requiring 

performance testing that the CEMS are sufficient to meet the initial and ongoing performance 

testing requirements. The commenter suggested that EPA provide clarification on the intent and 

extent of §63.1349 (c).

Response: Section 63.1349 (c) specifies that where CEMS is used for monitoring, performance 

testing is not required.
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Comment: One commenter (2845) stated that the final rule should clarify if each vent must 

demonstrate compliance for situations where there are multiple vents since there is no language 

in the current proposal regarding sources with multiple stacks for a common source(s).

Response: We believe the rule is sufficiently clear that each source must demonstrate 

compliance, regardless of the number of stacks or vents.

Comment: One commenter (2845) stated that §63.1349(f) and (g) appear to be direct excerpts 

from proposed HMIWI NSPS – 40 CFR §60.50, and stated that these references do not apply to 

cement plants. Section 63.1349(a) already states what is required to be submitted as part of the 

report required under the PC MACT regulation. The commenter noted that there is a 

typographical error between bullets 3 and 4, and section (g) appears to have been added in error.

Response: EPA has revised the section by removing paragraphs (f) and (g).

Comment: One commenter (2845) stated that in §63.1350(g), the rule should clarify that carbon 

injection requirements only apply to sources utilizing carbon injection for dioxin/furan control.

Response: The rule is clear regarding monitoring requirements that apply to sources using 

sorbent injection for D/F control.

Comment: One commenter (2845) stated that in §63.1350(g)(6), the reference to mercury and

THC should be removed to be consistent with regulatory text.

Response: EPA has removed the reference to mercury and THC.

Comment: One commenter (2845) stated that Table 1 to §63.1350 was not updated in the 

proposed rule. 

Response: Table 1, Applicability of General Provisions, is updated.

Comment: One commenter (2845) suggested that EPA delete all sections in 63.1353, 63.1354, 

and 63.1355 that reference subpart A and provide a paraphrase of subpart A. The commenter 

noted that because Table 1 will contain a listing of the sections of subpart A that apply and those 

that do not apply, sections that reference subpart A and provide a paraphrase of subpart A should 

be removed to prevent multiple interpretations.

Response: Sections 63.1354, 63.1355, and 63.1356 are being retained because many of the 

recordkeeping and reporting requirements specific to this rule, are not contained in the General 

Provisions.

Comment: One commenter (2845) suggested that §63.1355(d) is no longer needed, and can be 

deleted. 

Response: See previous response.

Comment: One commenter (2845) suggested that §63.1355(e) can be deleted, because it is a 

duplicate of §63.1350(o)(2). The commenter noted that the reference to only area sources in 
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§63.1355(e) may be a typographical error, as the recordkeeping requirement applies to both 

major and area sources. 

Response: The rule requires both area sources and major sources to keep clinker production 

records.

Comment: One commenter (2845) stated that §63.1350(o) no longer requires fly ash 

certifications so §63.1355(f) should be deleted.

Response: This is correct.

Develop waste disposal requirements

Comment: One commenter (2816) stated that EPA’s sector-based approach should include 

consideration of solid waste impacts and should reinvigorate its efforts to develop stringent 

regulations governing the disposal of wastes generated by portland cement kilns

Response: Comments on regulatory measures for cement kiln dust waste are beyond the scope 

of this proceeding.

Comment: One commenter (2895) stated that site specific regulation of CKD should be in each 

facility’s Title V permit. The commenter asked how CKD will be disposed of without creating 

water and solid waste problems if it is not recycled into the kiln.

Response: Site specific permitting issues relating to waste management are beyond the scope of 

this proceeding.

Comment: One commenter (2844) stated that the technical, economical and environmental 

implications of landfilling or blending cement kiln dust rather than recycling it to the kiln are 

significantly negative and should be avoided.

Response: EPA took this issue into account in determining not adopt beyond the floor standards 

as part of its consideration of non-air quality impacts.

More stringent dioxin/furan standards

Comment: One commenter (2828) suggested that EPA set more stringent standards for dioxins 

and furans. The commenter stated that the cement industry represents a high and disproportionate 

cancer risk. The science of dioxin/furan monitoring has improved to the point that commercial 

dioxin/furan CEMS are available, and analytical laboratories can measure dioxin/furan at 

significantly lower levels thanks to technologies such as gas chromatography-mass spectrometry

(GC-MS-MS). The commenter suggested that EPA should establish stringent dioxin/furan 

emission standards, based on a comprehensive study of dioxin/furan emissions from the current 

fleet of kilns, and recognizing that the RTO technologies already in place at some kilns, and 

likely to be installed at other kilns in the future are bound to be extremely effective (99%+) at 

destroying dioxin/furan. EPA should require dioxin/furan CEMS for monitoring (or at the very

least quarterly monitoring) for any cement kiln not using an RTO to control emissions. EPA 

should consider the beyond-the-floor possibilities for dioxin/furan control that are now possible 
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with the advent of SCR systems on cement kilns. If EPA continues recent practice of trying to 

integrate MACT and NSPS rulemaking for particular industries, then the establishment of SCRdriven NOx standards in the Portland Cement NSPS would integrate and support the 

establishment of SCR-driven dioxin/furan standards in the Portland Cement MACT rules.

Response: EPA did not reopen or reconsider the 1999 standard for CDD/CDF and so is not 

addressing this comment.

Comment: One commenter (2911) stated that EPA’s dioxin standards do not satisfy the 

requirement of §112 that standards must reflect the average emission level achieved by the best 

performing 12 percent of sources for which EPA has emissions information. The commenter 

provided additional arguments in support of this statement. The commenter petitioned EPA to 

revise its dioxin standards for cement kilns under the authorities described in Kennecott Utah 

Copper Corp. v. Department of Interior, 88 F.3d 1191 (D.C. Cir. 1996).

Response: EPA did not reopen or reconsider the 1999 standard for CDD/CDF and so is not 

addressing this comment here. EPA will consider the commenter’s petition request separately 

from this rulemaking.

Comment: One commenter (2144) stated that consideration should be given to more frequent 

measurement of dioxin and furan (D/F) from cement kilns or to the possibility of requiring D/FCEMS. One D/F test per 30-month period followed by continuous temperature measurement and 

control is not sufficient to ensure year round compliance at some kilns. In the short run, increase 

the minimum frequency of dioxin/furan testing to once every 12 months and begin assessment of 

D/F-CEMS.

One commenter (2867) emphasized the need for more dioxin/furan testing to a minimum of once 

every 12 months and recommended that EPA begin assessment of dioxin/furan-CEMS.

Response: EPA did not reopen or reconsider the 1999 standard for CDD/CDF and so is not 

addressing this comment.

Regulatory approach allows flexibility in fuels

Comment: One commenter (2846) supported EPA in developing a regulatory approach that 

maximizes the usefulness of secondary materials. The commenter recommended using a 

straightforward qualitative principle-based approach to defining solid waste that recognizes the 

inherent advantages of useful energy recovery and materials handling practices under §112 

regulation. Such an approach can be more universally applicable to not only existing materials, 

but also for new materials and processes not yet developed. Trying to be too prescriptive could 

inhibit new technology development and implementation and work against high level national 

goals. 

Response: EPA acknowledges the commenter’s support. On the matter of defining solid waste, 

that involves issues beyond the scope of this rulemaking.
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Solid waste as fuel

Comment: One commenter (2816) supported EPA’s inclusion of cement kilns that combust 

secondary materials in the proposed rule. One commenter (2895) stated that EPA should provide 

a conclusive definition of solid waste, and in particular, define the HAP emitted when these solid 

wastes are used as fuel.

Response: This issue is beyond the scope of this rulemaking. The definition of solid waste for 

purposes of section 129 is part of a different regulatory proceeding. See 75 FR 31844, June 4, 

2010. EPA is also performing a concurrent rulemaking, the Commercial and Industrial Solid 

Waste Incinerator rulemaking under section 129 of the CAA that will regulate kilns that burn 

non-hazardous solid waste. At the time that rule becomes final, kilns burning solid waste (as 

defined in the to-be-completed rulemaking) will be regulated under to-be-adopted standards for

commercial and industrial solid waste incinerators whenever they are burning solid waste.

Require natural gas

Comment: One commenter (2893) suggested that EPA require the use of natural gas where 

available as less-polluting alternative to other fossil fuels or other hazardous fuels.

Response: EPA acknowledges that the use of natural gas would reduce emissions of mercury

and other HAP in comparison to coal. We have considered this approach but rejected it as an 

approach that would be available to all cement plants on a nationwide basis. (71 FR 76520, 

December 20, 2006).

Alternatives to cement and concrete

Comment: One commenter (2893) suggested volcanic ash as an alternative to some 

conventionally manufactured cement, and alternative materials as substitutes for the use of 

concrete in certain applications.

Response: Investigating alternatives to conventionally manufactured cement, and exploring 

substitutes for concrete that may be used in certain applications is beyond the scope of this 

rulemaking.

Benefits to industry of sector approach

Comment: One commenter (2898) agreed with EPA’s discussion of its sector-based approach 

and of the impacts of the rule, stating that it is a useful reminder for the portland cement 

manufacturing industry that complying with the emission standards may help the industry meet 

other pollution requirements. The commenter suggested that EPA discuss changes in production 

practices or processes that may help facilities comply with the emission standards. While this 

discussion should in no way influence the final standards promulgated as the MACT floor, a 

fuller discussion of these alternatives to incorporate consideration of potential co-benefits will 

make EPA’s discussion a more useful tool for the facilities trying to meet the standards and for 

the communities living near these facilities as they evaluate the actions of the facilities in their 

midst. Moreover, these co-benefits are important considerations in any evaluation of the 

technologies for beyond-the-floor standards. The commenter described aspects of energy
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efficiency, adjusting the composition of cement, and cleaner fuel as examples of actions that 

could provide these co-benefits.

Response: EPA acknowledges the commenter’s support of EPA’s sector-based approach.

CO and combustion practices

Comment: One commenter (2928) stated that high CO levels are very often an indication of 

poor combustion practices and should also be kept as low as practical.

Response: A discussion of the EPA’s decision not to regulate CO can be found in the preamble.