# Reducing Hazardous Air Pollutants from Industrial B oilers: oilers:
Model Permit Guidance Model Permit Guidance

June 2008 June 2008

________________________________________

444 North Capitol Street, NW, Suite 307 Washington, DC 20001 Phone: (202) 624-7864 * Fax: (202) 624-7863 Web Site: www.4cleanair.org

E-mail: 4cleanair@4cleanair.orgii

# About NACAA About NACAA

The National Association of Clean Air Agencies (NAC AA) is the association of air pollution control agencies in 53 states and territo ries and more than 165 major metropolitan areas throughout the country. The mem bers of NACAA have primary responsibility for implementing our nation’s air po llution control laws and regulations. The association serves to encourage the exchange of inf ormation and experience among air pollution control officials; enhance communication and cooperation among federal, state and local regulatory agencies; and facilitate air p ollution control activities that will result in clean, healthful air across the country. NACAA has its headquarters in Washington, DC.

For further information, contact NACAA at 444 North Capitol Street, NW, Suite 307, Washington, DC 20001 (telephone: 202-624-7864; fax: 202-624-7863; email 4cleanair@4cleanair.org) or visit our association’s web site at www.4cleanair.org.ii 

# Acknowledgements Acknowledgements

On behalf of the National Association of Clean Air Agencies (“NACAA”), we are pleased to provide Reducing Hazardous Air Pollutants from Industrial Boilers: Model Permit
Guidance. NACAA has undertaken a review of available emissions information and applicable law to develop a Permit Guidance to assi st state and local permitting authorities in their efforts to comply with section 112(j) of t he Clean Air Act (“CAA”). This law requires these agencies to issue permits on a case-by-case b asis to limit emissions of hazardous air pollutants from industrial, commercial and institut ional boilers and process heaters (“ICI Boilers”) by application of the Maximum Achievable Control Technology (“MACT”). This Permit Guidance outlines the substantive legal and engineering issues and the procedural, data and timing requirements for development and is suance of permits under section 112(j).

NACAA expresses its gratitude to Bruce Buckheit for his assistance in compiling the underlying data and drafting this document. We als o thank Vinson Hellwig (MI) and Robert Colby (Chattanooga, TN), the co-chairs of NACAA’s A ir Toxics Committee, under whose guidance this document was prepared. We also acknow ledge and appreciate the efforts of the NACAA ICI Boiler Permit Guidance workgroup, part icularly Praveen Amar (NESCAUM), Elizabeth Basil (SC), Andrew Bodnarik (NH), Patricia Buonviri (VA), Daniel Donohoue and Michelle Komlenic (CA), Lance Ericksen (Monterey, CA ), Michael Mills and Mohsen Nazemi (Los Angeles, CA), Gerald Ebersole (OR), Roger Frit z (WI), David Riddle (MI), James Hodina (Cedar Rapids, IA), William O’Sullivan, Sunila Agra wal, Olga Boyko, Yogesh Doshi, John Jenks, Ray Papalski, Erica Snyder and John Walsh (NJ) , John Paul, Jennifer Marsee and Chris Clinefelter (Dayton, OH), Brad Reid (NE), Jim Snead and William Harris (DE) and Christine Weaver (MT). We are grateful for the comments and input provided by other state and local air pollution control officials, who helped shape t he options presented in this document. Finally, we thank S. William Becker, Executive Direct or of NACAA, and Mary Sullivan Douglas, Senior Staff Associate of NACAA, who oversaw the pr oject.

NACAA believes this Permit Guidance will serve as a useful and important resource for states and localities as they develop approache s to regulate emissions of toxic air pollutants from ICI Boilers and thank all of those w ho contributed to its development.

CO - PRESIDENTS PRESIDENTS PRESIDENTS

Andrew Ginsburg (Oregon) Ursula Kramer (Tucson, AZ)iii 

# T T able of able of able of C ontents ontents ontents

EXECUTIVE SUMMARY 1

BACKGROUND BACKGROUND 4

SECTION 112(J) REQUIREMENTS SECTION 112(J) REQUIREMENTS 8

NACAA’s Response 9

Recommended Subcategories 12

HAZARDOUS AIR POLLUTANTS HAZARDOUS AIR POLLUTANTS –

– ICI BOILERS ICI BOILERS ICI BOILERS 14

SURROG SURROGATES ATES 15

ESTABLISHING A MACT FLOOR ESTABLISHING A MACT FLOOR 16

EPA’s Approach 16

NACAA’s Approach 17

EXISTING SOURCE MACT FLOOR EXISTING SOURCE MACT FLOOR 19

Carbon Monoxide 19

Gas-Fired Boilers 19

Oil-Fired Boilers 21

Wood-Fired Boilers 23

Coal-Fired Boilers 25

Particulate Matter 26

Oil-Fired Boilers 26

Wood-Fired Boilers 28iv



# Table of Contents (continued)

Coal-Fired Boilers 30

Hydrogen Chloride 32

Wood-Fired Boilers 34

Coal-Fired Boilers 35

Oil-Fired Boilers 36

Additional Data 37

Mercury 37

Wood-Fired Boilers 38

Coal-Fired Boilers 39

CONTROL STRATEGIES CONTROL STRATEGIES –

– TECHNIQUES AND COSTS TECHNIQUES AND COSTS TECHNIQUES AND COSTS 40

CO Control for Organic HAP Reduction 40

PM Control for Metal HAP and Mercury Reductio n 41

Acid Gas Control for Acid Gas HAP Reduction 43

ESTABLISHING MACT ESTABLISHING MACT 45

MONITORING AND REPORTING REQUIREMENTS MONITORING AND REPORTING REQUIREMENTS 47

INCORPORATING MACT GENERAL PROVISIONS INCORPORATING MACT GENERAL PROVISIONS 49

DETERMINING A COMPLIANCE DATE FOR EACH FACILITY DETERMINING A COMPLIANCE DATE FOR EACH FACILITY 51

REASONABLE PROCESSES AND PROCEDURES FOR REASONABLE PROCESSES AND PROCEDURES FOR
CASE- BY - CASE MACT DETERMINATIONS CASE MACT DETERMINATIONS CASE MACT DETERMINATIONS 52

De Minimis Exemptions 52

Risk-Based Exemptions 53

Total Selected Metals Alternate Compliance Op tion 55v



# Table of Contents (continued)

Establishing Limits for ICI Boilers That Burn Mixed
Fuels 56

Establishing CO Limits During Turndown Period s 56

Compiling an Administrative Record 56

ESTABLISHING MACT LIMITS FOR NEW ICI BOILERS ESTABLISHING MACT LIMITS FOR NEW ICI BOILERS 57

COMPLIANCE DEMONSTRATIONS COMPLIANCE DEMONSTRATIONS 58

MODEL PERMIT PROVISIONS MODEL PERMIT PROVISIONS 59

Authority 59

Definitions 59

Covered Units 59

Procedural Issues 59

Emission Limitations 60

GLOSSARY OF ABBREVIATIONS AND ACRONYMS GLOSSARY OF ABBREVIATIONS AND ACRONYMS 61

APPENDICES APPENDICES 63

Appendix 1 – Example Section 112(j) Part 1 App lication 63

Appendix 2 – Example Section 112(j) Part 2 App lication 68

Appendix 3 – NACAA’s Request for ICI Boiler Da ta 70

Appendix 4 – Summary of Health Effects of HAPs Emitted by ICI Boilers 771 

# Executive Summary Executive Summary

Reducing Hazardous Air Pollutants from Industrial B oilers: Model Permit Guidance is intended to provide state and local air pollution c ontrol agencies with important tools for regulating hazardous air pollution from the approxi mately 3,000 industrial, commercial and institutional boilers and process heaters (ICI Boil ers), ranging from refineries and paper mills to manufacturing plants, operating in every state i n the country.

NACAA published Permit Guidance in response to a J une 2007 decision by the U.S. Court of Appeals ( Natural Resources Defense Council v. EPA , No. 04-1385) vacating rules promulgated by the U.S. Environmental Protection Ag ency (“EPA”) under Section 112 of the Clean Air Act (“CAA”) establishing emission limits for hazardous air pollutants (“HAPs”) for
these facilities. When EPA fails to meet a deadlin e for establishing limits under section 112 of the CAA (or where the Court vacates a rule), sta te and local permitting authorities are required under section 112 (j) – the “hammer provis ions” – to set the limits for the affected facilities on a case-by-case basis. These limits m ust be based on the use of the Maximum Achievable Control Technology (“MACT”) and may not be less stringent than the MACT floor, defined as the average of the best performing 12 pe rcent of sources in the industrial category.

Because of the potentially significant workload ass ociated with developing MACT limits on a case-by-case basis for the large number of affected sources, and the short deadlines imposed by the CAA for state and local ac tions, the NACAA Board of Directors authorized the development of this Permit Guidance. NACAA selected a technical workgroup, comprised of 17 state and local air pollu tion control agencies, to gather and review available information and provide recommenda tions for making MACT

determinations. A consultant assisted the associat ion in its efforts.

In the course of developing this guidance, in Nove mber 2007, NACAA requested that its members forward to the workgroup existing emissi ons data relating to ICI Boilers. The workgroup received several thousand emissions data p oints, including over 750 for two “criteria pollutants” – carbon monoxide (“CO”) and particulate matter (“PM”) – that could serve as regulatory surrogates for acetaldehyde, be nzene, cadmium, chromium, manganese and numerous other organic and metal hazardous air pollutants (HAPs). The emissions data are available on www.4cleanair.org (under “Our Proj ects”). Thereafter, the workgroup held teleconferences on a bi-weekly basis to discuss the data as they were being received and to develop a set of recommendations for MACT, availabl e technologies and permit conditions.

What NACAA found is quite revealing. In most inst ances, EPA’s vacated emission limits would have required no emissions reductions at all from ICI Boilers. NACAA’s recommendations, on the other hand, are far more st ringent than the limits in EPA’s vacated2

rule and require reductions in emissions from betwe en 55 and 85 percent of existing ICI Boilers. Table 1 compares the NACAA recommended lim its with those in EPA’s vacated rule.

NACAA has also reviewed the technologies that are available to allow existing sources to comply with its recommended MACT limits. These technologies have been commonly employed for many years to control criteria polluta nts, and have been demonstrated to be technologically-feasible and cost-effective.

NACAA believes the process of developing this Perm it Guidance has been inclusive, objective and transparent. We hope permitting auth orities will find it helpful and informative as they proceed to craft permits for the ICI Boiler s within their jurisdictions.3

TABLE 1 TABLE 1 – SUMMARY OF EPA AND NACAA RECOMMENDED LIMITS FOR IC BOILERS SUMMARY OF EPA AND NACAA RECOMMENDED LIMITS FOR ICI BOILERS

(In lb/MMBtu, unless otherwise noted)

Gas

- fired Coal

- fired Wood

- fired Oil

- firedCarbon Monoxide NACAA D atabase 161 boilers 10 boilers 57 boilers 114 boilers

Average of T op 12% (or top 5) less than 0.0007

(1 ppm) 0.018 (20 ppm) 0.042 (54 ppm) 0.0007 (1 ppm)

EPA Vacated Rule 400 ppm for new

large and limited use boilers; no
limit for others 400 ppm for new

large and limited use boilers; no limit
for others 400 ppm for new

large and limited use boilers; no limit
for others 400 ppm for new

large and limited use boilers; no limit
for others

NACAA Proposal 3 -10 ppm

(0.002 - 0.007) 35 - 60 ppm

(0.025 - 0.040) 100 -150 ppm

(0.08 - 0.12) 3 -10 ppm

(0.002 -0.007)Particulate Matter NACAA D atabase No data 67 boilers 109 boilers 58 boilers

Avera ge of T op 12% (or top 5) 0.005 0.007 0.011

EPA Vacated Rule Not applicable

No control 0.025 new boilers;

0.07 existing large boilers; 0.21 existing limited use boilers;
no limit for small
boilers 0.025 new boilers;

0.07 existing large boilers; 0.21 existing limited use boilers;
no limit for small
boilers 0.03 new boilers;

no limit for existing
boilers

NACAA Proposal Not applicable

No control 0.008 - 0.012 for

existing boilers 0.01 - 0.02 for

existing boilers 0.015 - 0.025 for

existing boilersHydrogen Chloride NACAA D atabase Insufficient data 14 boilers 11 boilers 3 boilers

Average of T op 12% (or top 5) N/A 0.010 0.004 N/A

EPA Vacated Rule No control 0.02 new units; 0.09 existing units 0.02 new units;

0.09 existing units 0.0005 large new

unit; 0.0009 small
and limited-use new unit; 0.09 existing large unit

MACT F loor
Derived from Data No control 0.015 – 0.03 0.006 – 0.012 90 -95% remov al, 0.006 existing unitsMercury NACAA D atabase Insufficient data 10 boilers 8 boilers No data

Av erage of top 12% (or top 5) N/A 3.15 lb/TBtu 1.65 lb/TBtu N/A

EPA Vacated Rule No control 3.00 lb/TBtu new boilers; 9 lb/TBtu existing boilers 3.00 lb/TBtu new

boilers No control

MACT F loor
Derived from Data No control 4.50 – 7.50 lb/TBtu
90% removal 2.50– 4.50 lb/TBtu No proposal4 

# Background Background

When initially adopted in 1970, the CAA included s ection 112 1 , intended by Congress
to establish National Emission Standards for Hazard ous Air Pollutants 2 (“NESHAPs”), just as
sections 110 and 111 were to address the environmen tal impacts of “criteria” pollutants. In its initial form, section 112 required the EPA to p ublish a list of air pollutants determined to be hazardous and, within one year of publication of the list, adopt emission standards “at the level which in [the Administrator’s] judgment p rovides an ample margin of safety to protect the public health” from such hazardous air pollutant. Under this program, EPA was required to make its determination that a given leve l of exposure was “safe” without regard to costs, which could only be considered in determi ning the additional margin of safety 3 . For a variety of reasons, this “risk-based” approach to the regulation of HAPs proved unworkable. During the 20 years of the initial prog ram, EPA had developed NESHAPs for only seven (asbestos, beryllium, mercury, radionucl ides, inorganic arsenic, benzene and vinyl chloride) of the hundreds of HAPs that were c ommonly understood to present a human health risk. For example, no regulations had been a dopted for such obviously hazardous pollutants as acrolein, chromium, cadmium and nickel . Even where NESHAPs had been promulgated, substantial, time-consuming litigation over data, testing and risk analysis methods ensued and coverage was often limited to on ly a small subset of emitting sources.

The 1990 Clean Air Act Amendments (“CAAA”) sought to remedy these failures by fundamentally restructuring the program. In lieu o f the prior risk-based program, Congress provided for a technology-based program in which it identified the air pollutants adjudged to create an excessive level of risk and specified the level of technology to be applied to all major sources of HAPs. In the first phase, technol ogy-based solutions were to be employed without consideration of risk. Only after 4 Maximum Achievable Control Technologies MACT had been employed would “risk-based” regulatory app roaches be used to determine whether even greater reductions of certain HAPs wer e necessary to protect public health.

To avoid the litigation that had paralyzed the ear lier program and ensure that a minimum level of technology would be employed in ac cordance with its schedule, Congress

1 See, 42 U.S.C. 7412.

2 In 1977 the definition of “hazardous air pollutant ” was expanded to mean “an air pollutant to which n o ambient air quality standard is applicable and whic h in the judgment of the Administrator causes, or contributes to, air pollution which may reasonably be anticipated to result in an increase in mortalit y or an increase in serious irreversible, or incapacitating ly reversible, illness.” 42 U.S.C. 7412. Section 122, requiring EPA to study the need for regulation of four specif ic HAPs, was also added at this time.

3 See, Natural Resources Defense Council v. EPA , 824 F.2d 1146 (D.C. Cir 1987) (en banc).

4 Section 112(f) requires EPA to promulgate a risk-b ased standard within eight years of promulgation of a technology-based standard for a category if a more stringent standard is necessary to protect public h ealth with an ample margin of safety.5

constrained EPA’s discretion in developing and impl ementing the technology-based provisions of the program. Thus, while Congress pr ovided to EPA the discretion to categorize 5 such sources to facilitate developing regulations applicable to a group of sources, it did not empower EPA to determine the le vel of actual or potential emissions that would subject a specific source to regulation. Ins tead, Congress made that determination and, in addition, developed and promulgated a list 6 of 189 chemicals 7 (and chemical compounds) that were considered “hazardous” and req uired EPA to promulgate a NESHAP 8 for each identified category and subcategory of sou rces of actual or potential emissions of these pollutants. The Act defines the technology-b ased emission limit as

“the maximum degree of reduction in emissions of th e hazardous air pollutants subject to this section (including a pro hibition on such emissions, where achievable) that the Administrator, taking int o consideration the cost of achieving such emissions reduction, and any non-air quality health and environmental impacts and energy requirements, dete rmines is achievable for new or existing sources....” See, 42 U.S.C. 7412(d )(2).

The discretion 9 provided the Administrator in determining what is “achievable” in setting emission limits under section 112(d)(2) is limited by a narrow and objectively determined “MACT floor” set out in section 112(d)(3 ). This provision provides that the
maximum emission reduction that is deemed achievabl e for new sources

“shall not be less stringent than the emission cont rol that is achieved in practice by the best controlled similar source, as determined by the Administrator.” See, 42 U.S.C. 7412(d)(3).

For existing sources, the Act provides that the emi ssion limits promulgated by the
Administrator

1. may be less stringent than the new source emission limits, and

5 EPA is authorized to add to or revise the list of categories of sources (see, 42 U.S.C. 7412 (c)) in response to
new information and has done so on several occasion s. With respect to the ICI Boiler category, EPA re vised the

list to combine industrial boilers with commercial and institutional boilers and process heaters. In its vacated rule EPA appears to have impermissibly attempted to “delist” or exempt indirect-fired process heaters and firetube boilers. Under the CAAA such sources must be included in some category unless they are not major sources of listed HAPs. Since the required promulg ation date for all categories has now passed, secti on 112(j) would seem to apply to any major source of HAP (in a listed source category) not subject to some MACT

standard.

6 This approach is similar to that employed by Congr ess under the Clean Water Act (“CWA”). The 1977 CWA Amendments incorporated a list of 129 toxic water p ollutants (now 148) to be regulated (33 U.S.C. 1317 (a)).

7 One of the initial listed HAPs has been “delisted” in accordance with a procedure set out in the CAAA

. 8 Such standards are technically “NESHAPs” under the CAA. Standards developed under the CAAA are requi red to be based on the application of “Maximum Achievab le Control Technology” and are colloquially known a s “MACT standards.”

9 That Congress did not provide carte blanche to EPA in determining whether a technology was “ac hievable” can be inferred from the fact that Congress was fam iliar with EPA practice in implementing Best Availa ble Control Technology requirements, which also provide for consideration of costs, in implementing New So urce Review requirements under the CAA and employed near ly identical language in establishing the MACT provision.6

2. may be more stringent, but may not be less stringen t, than the average emission limitation achieved by the best performing 12 perce nt of existing sources (for which the Administrator has emissions information) or the average emission limitation achieved by the best performing five sources in a c ategory or subcategory with
fewer than 30 sources. Id.

On September 13, 2004, EPA promulgated a MACT Stan dard for the ICI Boiler category. 10 On June 8, 2007, the U. S. Court of Appeals for t he District of Columbia issued

its decision in Natural Resources Defense Council v. EPA , No. 04-1385, a case that involved challenges to two rules promulgated by EPA. The fi rst rule attempted to define the universe of facilities subject to emission limitations for b oth hazardous and criteria pollutants for

commercial and industrial solid waste incineration units under section 129 of the CAA. The
second rule was the ICI Boiler MACT rule. The chal lenges to these two rules were consolidated by the Court because the issues are re lated. If a source is subject to regulation under section 129, it may not be regulated under se ction 112. The Court determined that
EPA’s definition of “solid waste” under section 129 was impermissibly narrow and that this decision would necessarily impact the calculation o f the MACT floor for ICI Boilers. For this
reason the Court “vacated” both rules.

Where the Court “vacates” a regulation, as distinc t from “remanding” it to the agency for further consideration, it is as if the regulati on never was promulgated. As a consequence, section 112(j) of the CAA has been tri ggered. The matter is further complicated because permitting authorities cannot s imply adopt the vacated ICI Boiler MACT standard. EPA’s ICI Boiler MACT rule was adopted at about the same time as a number of other MACT standards and used the same general appr oach to calculating the MACT floor as was employed in those standards. In resolving chal lenges to those other standards 11 , the Court determined that EPA’s basic approach to calcu lating the MACT floor did not comply with the CAA and rejected EPA’s attempts to create exemptions not authorized by the statute. Sources within this ICI Boiler category m ust obtain permits 12 issued by state or local permitting authorities on a case-by-case basis inco rporating emission limits that the state or local permitting authority determines is equivalent to the limitation that would have applied
if EPA had issued the ICI Boiler MACT standard in a timely manner.

The ICI Boiler category is large and diverse. It includes approximately 3,000 units that combust coal, natural gas, distillates, residu al oils, wood and agricultural materials that are located at a “major source” of hazardous air po llutants. “Major source” is defined as

“any stationary source or group of stationary sourc es located within a contiguous area and under common control that emits or has the potential to emit, considering controls, in the aggregate, 10 to ns per year or more of any hazardous air pollutant or 25 tons per year or more of any combination of hazardous air pollutants....” See, 42 U.S.C. 7412 (a) (1) and 40 CFR 63.2.

10 This standard is found in 40 CFR 63, Subpart DDDDD

. 11 See, Sierra Club v. EPA, 479 F3d 875 (D.C. Cir. 2007).

12 Under applicable regulations, these permits are to be written as modifications to the operating permi t issued
to the source under Title V of the CAA. 42 U.S.C. 7 661. See also, 40 CFR 65.52(a).7

Among the sources that are within this major source category are petroleum and natural gas extraction operations; pulp and paper m ills; refineries; blast furnaces, manufacturers of steel, rubber and plastic products ; as well as automobile parts manufacturing and electroplating operations. In add ition to such industrial operations, the major source category encompasses commercial and in stitutional boilers providing heat and/or power at educational institutions, prisons a nd office buildings, as well as small electric generating units of less than 25 megawatts (“MW”). The statutory definition does not limit applicability to individual units that em it a threshold amount of HAPs. Instead, it includes all HAP-emitting units at a source where t he total HAP emissions from the source exceed the threshold. This requirement makes sense in many applications, such as refineries, where many smaller units at the source may emit the majority of certain HAPs from the source. However, this structure does pres ent challenges to EPA and section 112(j) permit writers in other instances – at a large pape r mill, even a residential-sized hot water heater servicing the employees’ locker rooms is theo retically subject to regulation 13

.

13 NACAA proposes a solution to this problem below.8 

# Section 112(j) Requirements Section 112(j) Requirements

In pleadings filed with the Court by the U.S. Depar tment of Justice on behalf of EPA, the federal government has stated that the requirem ents of section 112(j) of the CAA would apply if the Court vacated the ICI Boiler MACT. EP A has also acknowledged this obligation in notices relating to EPA’s compliance with the Paper work Reduction Act. See, 72 FR 62226, November 2, 2007. Section 112(j) applies to source s located in a state with an effective Title V permit program 14 that are within a category or subcategory for whic h a MACT standard was required to be promulgated by a certai n date and EPA failed to promulgate the standard by the required date.

Sources subject to the requirements of section 112 are required to submit a permit application to the permitting authority 15 within 18 months of the statutory date for issuanc e of the MACT standard at issue. See, section 112(j) (2). The date specified by statute for sources in the industrial boiler and process heater category to submit a complete 16 permit application is August 13, 2005. However, the statu te did not contemplate the retroactive
failure to issue a standard that occurs when the Co urt vacates a standard in its entirety rather than remanding the standard to the agency fo r further proceedings. Since the vacatur did not occur until June 2007, literal comp liance with the statute was impossible. For this reason there is an ongoing debate over how long sources should be allowed, under present circumstances, to reach compliance with the statutory requirement. Some may argue that sources should be allowed an additional 18 months to submit an application 17

, while others will suggest that sources are under an obligation to apply for a permit as soon as practicable and that the information required is not substantial. (See exemplar permitting authority section 112(j) application forms, Appendi ces 1 and 2). Under 40 CFR 63.52(a)(2) if a permitting authority notifies a source that on e or more emission units at the facility are within the industrial boiler and process heater cat egory, the source must submit an application within 30 days. This suggests that sour ces are not expected to need a substantial amount of time to submit their applicat ions. Other provisions respecting the

14 The CAAA also adopted requirements that major sour ces obtain operating permits that consolidate emiss ion limits imposed under different CAA programs and imp rove emission monitoring. These requirements are f ound
in Title V of the CAA.

15 An additional copy must also be submitted to EPA. See, 40 CFR 63.55(b).

16 EPA regulation (40 CFR 63.53) sets out the require ments for a complete application, which includes a Part 1 (notice only) and a Part 2 (information about each covered emission point).

17 This argument is rapidly becoming moot since Decem ber 2008 is 18 months from the date of the Court’s decision. Some industry representatives have argue d that case-by-case permitting should be deferred a nd that EPA should be provided sufficient time to propose a nd promulgate a new rule. This position would, in effect, eliminate the “hammer” provision and is clearly con trary to the statute.9

submission of section 112(j) applications also sugg est that the time frame allowed for submission of applications should be relatively sho rt 18

.

Within 60 days of submittal of a Part 2 application , the permitting authority must notify the source operator in writing of its determ ination as to whether the application is complete and provide an additional reasonable perio d of time, not to exceed six months, to remedy any deficiencies. During this period the pe rmitting authority may require the source to provide additional information needed to process the permit application. Submission of a timely and complete application constitutes complia nce by the source with section 112(j), unless a delay in issuing the final permit is occas ioned by a source’s subsequent failure to provide information in a timely manner. The permit ting authority is required to issue the Title V permit, meeting section 112(j) requirements , within 18 months of the submittal of a complete Part 2 MACT application. See, 40 CFR 63.5 2(g).

The CAA requires that the Title V permit contain em ission limitations that the permitting authority determines on a case-by-case b asis are equivalent to the limitation that would apply to the source had EPA promulgated a MAC T standard in a timely manner. Where, as here, EPA’s central methodology for issui ng a MACT floor has been found unlawful, permitting authorities cannot be expected to divine the specific standard that will ultimately be promulgated. Given the range of poli cy choices involved in the case-by-case determinations, it is also likely that permitting au thorities will reach different decisions in certain areas. Section 112 can only be read to req uire that each of the case-by-case determinations be within the range of decisions aut horized by the CAA.

EPA has generally interpreted section 112 to requir e only that decisions of the permitting authority be consistent with the statuto ry definitions of MACT, and that the permit contain monitoring, certification and reporting req uirements consistent with the Title V permit program. See, 40 CFR 63.55. EPA’s regulati on requires that in the course of making a section 112(j) determination, the permitting auth ority must establish a MACT floor based
on available information and establish a MACT limit that is not less stringent than the floor. See, 40 CFR 63.55(a)(2). EPA further notes 19 that nothing prevents a state or local permitting authority from establishing an emission limitation that is more stringent than required by federal regulations.



## NACAA’s Response

Because of the potentially significant workload asso ciated with developing MACT floors and MACT limits for the large number of affe cted sources and the relatively short deadlines for state or local action imposed by the CAA, the NACAA Board of Directors

18 The regulations provide that where events subseque nt to the effective date of a MACT standard cause a MACT standard to be applicable to a source for the first time, the source must submit its application for a Title V MACT permit limit within 30 days of the triggerin g event. See, 40 CFR 63.52(b)(1), (b)(2), (b)(3) a nd (c)(2). In one instance the regulations provide six months for a source (that becomes a major source by virtue of state action) to submit a permit application. See, 40 CF R 63.52(b)(4). Here, sources have been on notice o f their status as major sources for several years and are n ot being transformed from a minor source to a major source by virtue of state action.

19 40 CFR 63.55(a)(5).10

directed the association’s staff to draft model gui dance to assist state and local permitting authorities in developing MACT permits for ICI Boil ers. A technical workgroup, with representatives from approximately 17 state and loc al air pollution control agencies, was formed to review available information and provide recommendations for case-by-case MACT determinations and development of MACT floors. A consultant was retained to assist the workgroup in gathering relevant information, col lating this information in a usable format and drafting (pursuant to direction from the techni cal workgroup) a Permit Guidance that permitting authorities may draw from as they see fi t.

In the course of preparing this report, NACAA has e ngaged in the following activities:

• reviewed the relevant legal decisions;

• reviewed EPA regulations and policy statements rela ting to the section 112(j)

process;

• reviewed selected state regulations and section 112 (j) application forms;

• reviewed the vacated ICI Boiler rule, as well as re lated rules, such as the Plywood MACT standard and the Brick and Clay MACT st andard;

• reviewed significant comments on the proposed EPA r ule;

• reviewed EPA rule-development materials and emissio ns data available in the public docket;

• discussed data issues with current EPA employees in volved in the MACTdevelopment process;

• met with representatives of vendors of pollution co ntrol equipment;

• met with representatives of the operators of indust rial boilers;

• met with and/or had telephone conversations with key state officials;

• met with representatives of environmental groups in volved in the Boiler MACT litigation; and

• commented on EPA’s proposed information collection request (“ICR”) concerning section 112(j) permit application forms and on EPA’s proposed ICR to support promulgation of a new proposal for a federal MACT standard for this category.

The data utilized by EPA in establishing the vacate d standard largely consisted of information concerning gaseous, liquid and solid fu el-fired boilers and process heaters gathered for the Industrial Combustion Coordinated Rulemaking (“ICCR”). Based on its initial review of these materials, NACAA concluded that this data set was extremely limited 20 and likely not representative of current operation o f this category of sources, with much of the available data from testing conducted 20 years ago or more. Moreover, as discussed above, the earlier data-gathering efforts were base d on an approach to setting the MACT floor that has subsequently been rejected by the Co urts. EPA has since reached the same conclusion about the adequacy of the earlier data s et and has announced plans to conduct a multi-year data acquisition and stack testing prog ram before attempting to repropose a
MACT standard for ICI Boilers.

20 In establishing the limits in the now-vacated rul e, EPA often relied on data relating to “a few” or “several”

sources.11

In the course of developing this Permit Guidance, N ACAA engaged in a far more rigorous and expansive data-collection effort than undertaken by EPA in developing prior
MACT standards 21 . In November 2007 NACAA requested that its member s forward to the technical workgroup existing emissions data relating to ICI Boilers for (1) hazardous air pollutants identified by EPA as associated with thi s category and (2) criteria pollutants that may serve as regulatory surrogates. See, Appendix 3. Replies were received from more than 40 state and local permitting authorities in a ll regions of the country. In a number of instances the permitting authorities reported that they did not have any useful information. However, those authorities that did have informatio n provided several thousand emissions data points. These data were screened to eliminate data in forms (such as tons per year or pounds per hour) that could not readily be employed to compare emissions performance between different-sized units. As of the date of p ublication of this Permit Guidance, NACAA’s data set included over 750 usable data points for c arbon monoxide (“CO”) and particulate matter (“PM”), reflecting the CO and PM performance of emission units of a wide range in sizes, fuels and locations. These data (see www.4c leanair.org, under “Our Projects”) all reflect the results of reference method testing, si milar to the test results employed by EPA. Moreover, since the permitting authorities that did have information provided data on all sources within their jurisdictions, there is no rea son to suspect a bias in NACAA’s data. We further believe that the NACAA data population is s ufficient in size and diversity to characterize CO and PM performance of ICI Boilers n ationally.

The statute reflects an understanding that emission s data for all sources in the category are not required or expected. Under secti on 112(j) the determination of the MACT floor is to be based on the average of the best per forming 12 percent of existing sources (for

which th which the Administrator has emissions information) e Administrator has emissions information) e Administrator has emissions information) (emphasi s provided). Moreover, in its implementing regulations at 40 CFR 63.51, EPA attem pts to preclude permitting authorities from requiring additional source stack tests under s ection 112(j) by excluding information that is not “available” (as of the date on which th e first Part 2 MACT application is filed in the relevant source category in the jurisdiction) from consideration in setting the MACT floor.

Thereafter, the data were sorted and analyzed to ge nerate emissions profiles for the relevant subcategories, and the average emissions p erformance of the best performing 12 percent of existing sources 22 for which emissions data were available was calcul ated. Finally, replicate testing of sources within the su bcategories was reviewed and statistical techniques used to calculate a variability factor t o be applied to the average of the top performing 12 percent in setting a MACT limit based on the available emission data.

21 EPA has been and will continue to be involved in t his process. NACAA representatives have met with E PA senior managers and technical staff on several occa sions and have received excellent cooperation to da te. EPA staff has been quite helpful in identifying exi sting sources of information. NACAA’s intent throu ghout this process has been to work with EPA to gather informa tion in a manner that avoids duplication of effort and inconsistent data-gathering formats. However, as s et out in the CAAA, where EPA has failed to meet a statutory deadline for promulgation of a MACT standard, case- by-case MACT permit determinations are state and lo cal functions, not an EPA function. NACAA has neither sought nor obtained the consent of EPA for its effo rts. NACAA’s efforts were neither requested by nor direc ted by EPA. These efforts are by and for the state and local permitting authorities that are required by the CAA A to issue permits within very tight timeframes.

22 Where the data subset contained fewer than 30 sour ces, the floor was calculated using the average of the best performing five sources. See, 42 U.S.C. 7412( d)(3)(B).12



## Recommended Subcategories

EPA’s vacated rule had created nine subcategories within the original category of industrial boilers and process heaters – small, lar ge and intermittent-use solid-fired units; small, large and intermittent-use liquid-fired unit s; and small, large and intermittent-use gasfired units. While the category of industrial boil ers and process heaters was established many years ago and is not challenged, the workgroup reviewed EPA’s initially suggested subcategories and determined that a different subca tegorization was more appropriate. The Permit Guidance recommends several changes to EPA’s approach:

1. Divide EPA’s solid fuel subcategory into two subcat egories – coal and wood/biomass. In the judgment of the workgroup, the emissions and performance characteristics of these two groups would likely differ substantially. The data confirm the workgroup’s judgment. NACAA believes that it would be exceedin gly difficult for sources that combust wood to match the CO performance expected o f coal-fired boilers (and inappropriate to allow coal-fired boilers to emit a t the rate expected for wood-fired boilers). Similarly, it would be inappropriate to require coal-fired boilers to match the mercury emission limitations achieved by wood-fired boilers (or to allow wood-fired boilers to emit at the rates expected of coal-fired boilers).

2. Retain the gas- and liquid-fired subcategories.

3. Eliminate the size subcategories adopted by EPA 23 , absent additional data demonstrating that there are fundamental difference s in achievable performance to justify a subcategory.

4. Delete EPA’s “intermittent use” subcategory, which appeared to be an effort to inject cost considerations into the process of setting the MACT floor rather than a reflection of inherent design or performance limitations.

Accordingly, NACAA is recommending four subcategor ies: coal, wood/biomass, gaseous and liquid (primarily oil). However, NACAA understands that as the case-by-case review of approximately 3,000 ICI Boilers unfolds, permitting authorities may become aware of other types of sources where creation of an addi tional subcategory may be appropriate 24

. NACAA is continuing to evaluate whether to create a n additional subcategory within the wood-fired boiler category and whether a separate c ategory for residual oil should be created within the liquid/oil-fired subcategory.

23 The absence of a compelling reason to stratify the category on the basis of the size of the unit can be seen in the NACAA data set. For example, the 10 wood-bu rning boilers with the lowest CO emissions in NACAA ’s data set ranged in capacity from 8.2–320 MMBtu/hr ( 4 of 10 units in this group were smaller than 60 MMBtu/hr). Similarly, the 10 wood-burning boilers with the lowest PM emissions ranged from 37.3 – 355 MMBtu/hr in capacity (4 of 10 units had a capacity of 60 MMBtu/hr or less). Two 760 MMBtu/hr units ar e the
11 th and 12 th ranked units, while a 60 MMBtu/hr unit is ranked 1 3 th

. 24 CO boilers, which combust nearly 100 percent CO (a nd therefore would not emit the HAP of concern), wo uld likely best be addressed by a separate subcategory, as would many externally fired process heaters.13

Finally, it appears that the section 112(j) proces s applies to all industrial boilers, including those that combust waste material, until such time as EPA promulgates an effective EPA rule under section 129 that regulates such boilers.14 

# Hazardous Air Pollutants Hazardous Air Pollutants --

-- ICI Boilers Boilers Boilers

In the course of developing the Permit Guidance, th e workgroup reviewed the HAPs of concern within the industrial boiler and process he ater category, as identified by EPA, and selected surrogate parameters or pollutants, where control of the parameter or pollutant will ensure good control of the HAP. The following elem ents, chemicals and compounds were identified by EPA in its initial source characteriz ation:

ethyl benzene (O-)xylene arsenic compounds
benzene cadmium compounds chromium compounds lead compounds manganese compounds mercury compounds nickel compounds selenium compounds
hexane toluene formaldehyde beryllium compounds phosphorous polycyclic organic matter

In the preamble to the vacated rule, EPA stated tha t emissions from ICI Boilers “include arsenic, cadmium, chromium, hydrogen chlor ide (HCl), hydrogen fluoride (HF), lead, manganese, mercury, nickel and various organic HAP.” See, 69 FR 55218, September 13, 2004. EPA also noted that formaldehyde, benzene, a nd acetaldehyde emissions represent “essentially all of the mass of organic HAP emissio ns“ from this group and that its toxics screening mechanism had identified manganese and ch lorine emissions as creating the greatest chronic health risk. Id , at 55220. A synopsis of known effects taken from EPA’s
Health Effects Notebook for Hazardous Air Pollutant s 25 and from EPA’s IRIS system is provided in Appendix 4.

25 http://www.epa.gov/ttnatw01/hlthef/hapindex.html.15 

# S S urrogates urrogates urrogates

The U.S. Court of Appeals 26 has held that EPA may use reasonable surrogates in setting technology-based standards under sections 1 12(d)(2) and (3) where the target pollutant is invariably present in the surrogate; t he control technology indiscriminately captures both the target and the surrogate and cont rol of the surrogate is the only means by which facilities achieve reductions in the target H APs.

In the course of its rulemaking, EPA determined tha t CO emissions may serve as a reasonable surrogate for control of the organic HAP s, that HCl may serve as a reasonable surrogate for control of inorganic (acid gas) HAPs and that PM may serve as a reasonable surrogate for a number of non-volatile metal HAPs 27 . This determination was generally accepted at the time by both industry 28 and environmental organizations. NACAA agrees that ensuring low CO, PM and HCl emissions is the m ost practical means of controlling organic, metal and inorganic (acid gas) HAPs. Acco rdingly, NACAA concurs with EPA’s determinations and utilizes these surrogates in thi s Permit Guidance.

26 National Lime Association v. EPA , 233 F.3d 625, at 639 (D.C. Cir 2000).

27 69 FR 55218, 55223, September 13, 2004.

28 For example, the Council of Industrial Boiler Oper ators (“CIBO”) submitted an extensive, 98-page, com ment on EPA’s proposed rule, noting, but not objecting t o, the use of the above-listed surrogates. See, EP A-HQ-OAR2002-0058-0449, March 13, 2003. CIBO has recently commented that it continues to support the concept of the use of surrogates, but offers a concern that va riability in source operation should be taken into account in establishing MACT floors.16 

# E E stablishing a MACT Floor stablishing a MACT Floor stablishing a MACT Floor

EPA regulation requires the states to establish a M ACT floor for new and existing units as part of the section 112(j) process and to set MACT limits that are not less stringent
than the floor. The floor is to be based on availa ble data and is not limited to data from sources with emission controls. CO, PM and HCl wer e determined to be reasonable surrogates for the relevant HAPs. Emissions data f or these pollutants and mercury were identified as essential to the development of the M ACT floor. Accordingly, the Permit Guidance development included a reasonable effort t o identify and evaluate all existing relevant data for these pollutants, including a rev iew of AP-42 and RACT/BACT/LAER Clearinghouse 29 information and other databases. In addition, NAC AA engaged in an extensive effort to obtain all existing relevant em issions data for ICI Boilers. The NACAAgenerated data set is the most comprehensive and ro bust compilation of data available for establishing a MACT floor for several surrogates. Where the NACAA data are limited, other information, including the ICCR data, is also consi dered.



## EPA’s Approach

In establishing the vacated MACT floor, EPA did not consider the actual performance of sources in each subcategory. Instead, EPA attem pted to identify a “MACT control technology” where more than 12 percent of the units in a subcategory employed postcombustion control devices. The “MACT control tech nology” was that used by the median performing unit within the group that employed cont rols. EPA did not then set the MACT floor at the level achieved by that unit. Nor did EPA set the MACT floor at the average performance of the top 12 percent of the units with controls.

Rather, EPA set the MACT floor at the “worst” emiss ion level that other units employing the “MACT control technology” might be ex pected to achieve. EPA determined the “worst” performance by the use of a nonstatisti cal “variability factor” based on an even smaller subset of data – units employing the “MACT control technology” for which multiple

emissions test data were available 30 . Where such emissions data were unavailable, EPA looked to fuels data to determine the potential vari ability in emissions from uncontrolled

units. In this manner EPA calculated the “worst co nceivable performance” of a few units employing the selected add-on controls and for whic h more than one set of HAP emissions

data was available.

29 The RACT/BACT/LAER Clearinghouse is maintained by EPA as a source of information concerning permittin g decisions that require the stated level of control. Similarly, AP-42 is an EPA-maintained compendium of emission factors for existing sources.

30 EPA’s rulemaking record is not altogether clear. It appears that in some instances EPA may have cons idered the variability in performance between different un its rather than the variability in performance of a given unit.17

Because of the limitations in the data set employed by EPA and the specific approach selected by the agency, the variability in the smal l data set determined the MACT floor in EPA’s vacated rule, rather than the average control performance of the group. For example, EPA reported that the average HCl emission limit fr om the best controlled eight large solidfueled boilers was 0.00962 lb/MMBtu, and the averag e “variability level” for this group was a factor of 9.08. Incorporating this “variability, ” EPA then calculated the MACT floor emission level for HCl for this subcategory to be 0 .09 lb/MMBtu – 9.08 times higher than the average emission limit of the best performing 1 2 percent of the sources with controls and fairly close to the uncontrolled performance of those units. In establishing the MACT floor limit for HCl for liquid-fired boilers, EPA s elected a variability level of 160 (16,000 percent) as the multiplier to be applied to the ave rage of the best-performing 12 percent, thus assuring that no ICI Boiler would have to redu ce acid gas emissions. In the case of CO emissions, EPA declined to establish a MACT floor b ecause it asserted that fewer than 6 percent of the ICI boilers were subject to pre-exis ting CO limits. This assertion is suspect as a factual matter. More importantly, the existence or lack of pre-existing enforceable limits is
not determinative of the level of a MACT floor.

This vacated EPA approach also failed to consider the effect of cleaner fuels in the overall emission performance of sources in the seve ral subcategories. EPA has acknowledged that in several instances units without add-on controls (using cleaner fuels) outperformed EPA’s best-performing units with add-o n controls. Additionally, as a consequence of its approach, where fewer than 12 pe rcent of the sources within a subcategory employed add-on pollution control devic es, EPA declined to set a MACT floor. In the Brick and Clay MACT decision 31 the Court reiterated its earlier rulings that the EPA approach 32 to establishing the MACT floor is inconsistent wit h the plain reading of section 112. The Court specifically ruled that EPA erred w hen it considered only the effect of add-on controls and ignored HAP emission reductions that m ay occur as the result of fuel switching or other emission-reducing techniques. Section 112 (d)(2) is explicit in setting out a list of other pollution-reduction techniques, including pro cess changes, substitution of materials, enclosure of systems or processes and work-practice requirements, that must be considered in setting a MACT standard.



## NACAA’s Approach

NACAA’s approach is an attempt at straightforward compliance with the CAA as written by Congress and interpreted by the Court. NACAA set out to gather all available emissions data concerning HAPs emitted by the categ ory and criteria pollutants that may serve as surrogates. As mentioned earlier, these d ata reflect the results of reference method testing and are of equal or better quality t han the test results employed by EPA. Moreover, since the permitting authorities that did have data provided information on all

31 Sierra Club v. Environmental Protection Agency , No. 03-1202 (March 13, 2007).

32 In the Brick and Clay MACT rulemaking EPA had esta blished the MACT floor as the performance of the wo rstperforming unit that employed the same technology a s the median of the top 12 percent of the units tha t employed add-on controls.18

sources within their jurisdictions, there is no rea son to suspect a bias in NACAA’s data. This
absence of bias cannot be asserted for information submitted by sources to EPA’s rulemaking docket in support of an argument for less stringent regulation 33 . NACAA further believes that the association’s data population is sufficient in size and diversity to characterize CO and PM performance of ICI Boilers n ationally. Where sufficient comparable data existed to calculate the average of the best-p erforming units, NACAA has done so. In

some instances the data set was robust and there is a relatively high degree of confidence that the data reflect the performance of the partic ular subcategory. Here we believe it is likely that the MACT floor accurately represents the performance of the best- performing units and likely represents MACT. In other instance s far less data were available and overall confidence in the degree to which the “floor” repre sents an accurate emissions profile of the subcategory is much lower. In these instances NACA A has also identified percent reductions
of recommended control devices that should lead to MACT levels of emissions when applied to a particular source.

After calculating the “average limitation achieved by the best performing 12 percent of existing sources,” NACAA developed a “variabilit y factor” based on an analysis of yearover-year testing of a number of sources in the dat a base. Generally, the workgroup did not attempt to discern why emissions varied over time. 34 The workgroup’s conclusion was that a variability factor of 1.5 to 2.5 35 , and, based on engineering judgment, sometimes up to 3.0 (150 to 250 or 300 percent) would reasonably accoun t for test-to-test variability of a given
unit. A closer examination of each of these source s may suggest that the variability is
overstated 36 and more data are always desired. Nonetheless, gi ven the time and budgetary constraints of this project, NACAA is comfortable w ith the selected adjustment factors.

As part of the process of setting the MACT floor, NACAA also examined the impact of the proposed floor limits on existing sources. It is reasonable to conclude that, given the structure of the MACT floor requirement, Congress e xpected that a properly established MACT floor would require a substantial portion of e ach subcategory (nominally 94 percent) to have to take some action to reduce emissions (eve n if only by a small amount).

33 NACAA has no reason to suspect that such informati on is incorrect, but notes that a commenter in a rulemaking matter is under no obligation to identif y or supply information that may contravene its arg ument.

34 In one instance an extremely large variance was no ted, however, the permitting authority indicated th at, in response to the earlier high emission test result, the source had installed a fabric filter that was r esponsible for the much lower results. This result was not employ ed in establishing the variability factor.

35 The factor of 1.5 reflects an average ratio betwee n the mean of the sample and the 90 th percentile confidence margin, while the 2.5 factor is the aver age ratio between the mean of the sample and the 99 th percentile confidence margin.

36 Most states use a smaller “variability factor” in translating the results of a reference method compl iance test (which is supposed to be conducted under “reasonabl e worst-case conditions”) to an enforceable limit.19 

# Existing Source Existing Source MACT Floor

MACT Floor MACT Floor

The following is a series of NACAA recommendations for setting the MACT floor. As can be seen in the figures, EPA’s vacated rule woul d have required very few sources to reduce emissions. In contrast, NACAA’s recommended MACT floor limits require between 55 and 80 percent of existing sources to take some acti on to reduce emissions. Below we provide below a detailed comparison of the vacated EPA limits, the NACAA
recommendations and the emissions data for the ICI Boiler subcategories.



## Carbon Monoxide

Gas- Fired Boilers Fired Boilers

Figure 1 displays the 161 CO emission test results for gas-fired ICI boilers that are in the NACAA data set, ranked from lowest-to-highest em ission level. Also displayed are EPA’s
intended emission limit for new sources and NACAA’s recommended range for a MACT floor determination for existing sources. Here it can be seen that EPA’s limit of 400 parts per million (“ppm”) for new

gas-fired boilers is easily met by almost all e xisting xisting existing boilers. EPA did
not establish either a MACT floor or MACT standard for existing gas-fired sources. Accordingly, EPA’s standard would have led to no re duction of HAP emissions from this large subcategory of ICI boilers.

The NACAA workgroup was surprised that so many sour ces had been tested at such low levels. Accordingly, the workgroup examined this matter more closely. Direct inquiries were made of the state and local air pollution cont rol officials who had witnessed the tests
to confirm these results. Based on these addition al efforts, NACAA is confident that a large portion of gas-fired boilers, of all sizes, will sh ow CO emission levels at or near detection levels when subjected to federal reference testing.20 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 1 39 145 151 157
Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

EPA - New Boilers - 0.294 lb/MMBtu (400 ppm) Gas-Fired Boilers

Carbon Monoxide Emissions

NACAA Range - Existing Boilers - 0.0021 - 0.007 lb/ MMBtu (3-10 ppm) Figure 1

Figure 2 presents the same data as above, but limit ed to the best-performing 50 percent of the sources on the previous figure.21 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.01

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

Emission Units - Rank Order of Performance (Top 50 Percent)Emission Rate (lb/MMBtu)

Avg of Top 12 Percent - Less than 0.0007 lb/MMBtu ( 1 ppm) NACAA Range - Existing Boilers - 0.0021 - 0.007 lb/ MMBtu (3-10 ppm)

Gas-Fired Boilers

Carbon Monoxide Emissions
Top 50 Percent Figure 2

The data are presented in this fashion to expand t he scale of the figure so as to allow the reader to evaluate the likely impact of NACAA’s recommended range. NACAA’s recommended MACT floor range for this subcategory ( 3 to 10 ppm) would require 85 to 110
sources of the total of 161 sources within this dat a set to undertake some level of emissionreduction effort to comply. That 51 to 76 sources would not have to take action is reflective of the large number of sources that have reduced CO emissions substantially. NACAA is recommending a very broad range that is larger than the calculated variation among sources to accommodate concerns about a potential t radeoff between CO and NO x emissions at very low CO levels and an understandin g that, even at 10 ppm, CO levels in this subcategory are far lower than will be required of solid-fueled ICI boilers. NACAA believes

this outcome is reasonable and more consistent with Congressional intent than that achieved by EPA’s approach.



### Oil - Fired Boilers Fired Boilers

Figures 3 and 4 present the CO emission testing re sults for the oil-fired boilers in the NACAA data compendium. Again, it is evident that EPA’s intended standard for new units has been exceeded by a wide margin by almost all ex isting units. Since EPA did not promulgate any standard for existing units, the vac ated rule would not have achieved any reduction in HAP emissions from this subcategory.22 Oil-Fired Boilers

Carbon Monoxide Emissions

0 0.1 0.2 0.3 0.4 0.5 0.6

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 1 05 109

Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

EPA - New Boilers - 0.311 lb/MMBtu (400 ppm)

NACAA Range - Existing Boilers - 0.002 - 0.007 lb/ MMBtu (3 - 10 ppm) Figure 3

Figure 4 again examines the likely impact of NACAA’s recommended MACT floor range on existing units in the subcategory. As in the gas-fired subcategory, NACAA is recommending a broad range (from 3 to 10 ppm) to ac commodate NO x /CO tradeoff concerns and to recognize the difference in expecte d performance of oil-fired boilers compared to solid-fired boilers. Twenty-seven to 45 percent of the existing sources in our database have already tested at levels below our re commended range. Again, we do not believe that it is unreasonable to adopt a standard that requires some level of HAP reduction from 55 to 73 percent of sources in the b etter-performing subcategory.23 Oil-Fired Boilers

Carbon Monoxide Emissions
Top 50 Percent

0 0.002 0.004 0.006 0.008 0.01 0.012

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57

Emission Units - Rank Order of Performance (Top 50 P ercent)Emission Rate (lb/MMBtu)

Avg of Top 12 Percent - 0.0007 lb/MMBtu (1 ppm) NACAA Range - 0.002 - 0.007 lb/MMBtu (3 - 10 ppm) Figure 4



### Wood - Fired Boilers Boilers

Figures 5 and 6 examine the performance of existing wood-fired boilers. Overall CO emissions are higher and EPA’s vacated limit for ne w sources comes closer to what one might anticipate as a limit for existing sources. The average emission limitation achieved by the best-performing 12 percent of the sources is 54 ppm. Applying the calculated variance
to this result would lead to a recommendation of 80 ppm to 125 ppm. The engineering judgment of the workgroup was that a larger varianc e was needed to accommodate unavoidable variations in moisture; accordingly, NA CAA is recommending a range of 100 ppm to 150 ppm.24 Wood-Fired Boilers

Carbon Monoxide Emissions

0 1 2 3 4 5 6 7

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55
Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

EPA - New Boilers - 0.311 lb/MMBtu (400 ppm) NACCA Range - Existing Boilers - 0.080 - 0.120 lb/M MBtu (100 - 150 ppm) Figure 5

In Figure 6 we examine the likely impact of the NACA A recommended range of 100 ppm to 150 ppm. Over 15 percent of existing source s already meet NACAA’s recommended limits. This is consistent with the statutory schem e that nominally requires the MACT floor to
be set at the 94 th percentile of existing units. Moreover, the inco mplete combustion represented by the current CO levels inevitably res ults in high levels of organic HAP

emissions that the statute was intended to reduce. The data demonstrate that the recommended CO range for this subcategory is achiev able by a wide range of sources. Our recommended range for CO is 10 to 50 times higher f or wood-fired boilers than for gas-fired or liquid-fired boilers.25 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Emission Units - Rank Order of Performance (Top 50 Percent)Emission Rate (lb/MMBtu)

Avg of Top 12 Percent - 0.042 lb/MMBtu (54 ppm ) NACAA Range - Existing Boilers - 0.08 - 0.12 lb/MM Btu (100-150 ppm)

EPA - New Boilers - 0.311 lb/MMBtu (400 ppm) Wood-Fired Boilers

Carbon Monoxide Emissions
Top 50 Percent Figure 6



### Coal- Fired Boilers Fired Boilers

As Figure 7 shows, NACAA’s CO data set for coal-fir ed boilers is more limited than for other subcategories and so, as the law requires, th e association has determined the MACT floor by calculating the average of the top five so urces rather than the top 12 percent. In this subcategory all sources were well below EPA’s limit of 400 ppm for new sources. The average of the five best-performing sources was 20 ppm. After applying a variance factor, the workgroup recommended a MACT floor range from 35 to 60 ppm. Six of the 10 units represented in our data set would comply with this recommended range of limits. The overall result is consistent with the experience ofthe workgroup: one would expect that gasfired and liquid-fired boilers would have lower emi ssions than coal-fired boilers and that each of these subcategories would have lower CO and organic HAP emissions than woodfired boilers.26 0 0.05 0.1 0.15 0.2 0.25 0.3

1 2 3 4 5 6 7 8 9 10
Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

Avg of Top 5 - 0.0177 lb/MMBtu (20 ppm) NACAA Range - Existing Boilers - 0.025 - 0.040 lb/ MMBtu (35 -60 ppm) EPA - New Boilers - 0.342 lb/MMBtu (400 ppm) Coal-Fired Boilers

Carbon Monoxide Emissions Figure 7



## Particulate Matter

Oil - Fired Boilers Fired Boilers

Figures 8 and 9 present NACAA’s data for Particulat e Matter for oil-fired boilers. EPA’s intended new source limit is not met by many existing sources within the subcategory, and, in fact, is reasonably close to NACAA’s recomm ended MACT floor range for existing units. However, EPA did not set a MACT floor or a MACT limit for existing sources and any new sources would likely have been required to meet the emission limitations of the bestperforming sources by installing Best Available Con trol Technology (“BACT”) under the New Source Review (“NSR “) program. Accordingly, EPA’s rule would not have resulted in any
metal HAP emission reductions.27 Oil-Fired Boilers

Particulate Matter Emissions

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57
Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

EPA - New Boilers - 0.030 lb/MMBtu NACAA Range - Existing Boilers - 0.015 - 0.025 lb/M MBtu Figure 8

As noted in Figure 9, the average of the top 12 per cent of units in PM emissions testing of oil-fired units in NACAA’s data set was 0.011 lb/MMBtu. After applying the computed range of variance factors, the workgroup re commended a MACT floor range of 0.015 to 0.025 lb/MMBtu. Approximately 20 percent of the units in our data set meet this limit. Again, where the statute contemplates that 94 percent of existing sources will have to take some steps to achieve compliance, a MACT floor that is calculated in accordance with both the existing data and the decisions of the Cou rt should produce the result that a substantial portion of the subcategory, here 80 per cent, exceeds the floor. The NACAA data set includes testing for particulate matter smaller than 10 microns in diameter (“PM 10 ”), as
well as PM. While PM 10 is not used as a surrogate, the emissions profile for this pollutant is similar to the results displayed here. The PM 10 data confirm that 20 percent of the existing
units have far lower PM emissions than the balance of the units in the subcategory.28 Oil-Fired Boilers

Particulate Matter
Top 50 Percent

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Emission Units - Rank Order of Performance (Top 50 P ercent)Emission Rate (lb/MMBtu)

EPA - New Boilers - 0.030 lb/MMBtu

NACAA Range - Existing Boilers - 0.015 -0.025 lb/MM Btu Avg of Top 12 Percent - 0.011 lb/MMBtu Figure 9



### Wood- F ired Boilers ired Boilers

The NACAA data for wood-fired boilers in Figures 1 0 and 11 include results for 109 sources. As Figure 10 depicts, for its solid-fuel subcategory, EPA had set a limit, based on a MACT floor calculation, for new solid-fired boilers of 0.025 lb/MMBtu. EPA also established a MACT floor limit of 0.07 lb/MMBtu for existing la rge units and 0.021 lb/MMBtu for existing, limited-use units. EPA’s limit for new s ources is reasonably close to NACAA’s recommendation for existing units and EPA’s limit f or large existing units would not have been met by approximately half of the existing unit s. Here, it is likely that the vacated rule
would have led to some reductions. The extent of t hose reductions cannot be estimated
because the number of sources that would have avoid ed emission reductions due to emissions averaging, alternate “Total Selected Meta ls” (“TSM”) limits, size or risk-based exemptions provided by the rule is unknown.29 Wood-Fired Boilers

Particulate Matter Emissions

0 0.2 0.4 0.6 0.8 1 1.2

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 1 05 109

Emission Units - Rank Order of PerformanceEmission Rate (lb/mmbtu) NACAA Range - Existing Boilers - 0.010 - 0.020 lb/M MBtu
EPA - New Boilers - 0.025 lb/MMBtu

EPA - Existing Boilers - 0.070 lb/MMBtu Figure 10

In Figure 11, the calculated “average of the top 1 2 percent” in this instance is 0.0076 lb/MMBtu. NACAA’s recommendation, after app lying a variance factor, is 0.010 to 0.020 lb/MMBtu. Based on existing data, this range is met by 10 to 25 percent of existing units and should be achievable through use of conve ntional PM controls that have been available for many years.30 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55

Emission Units - Rank Order of Performance (Top 50 P ercent)Emission Rate (lb/MMBtu) EPA - Existing Large Boilers - 0.070 lb/MMBtu

EPA - New Boilers - 0.025 lb/MMBtu

Avg of Top Percent - 0.0076 lb/MMBtu NACAA Range - Existing Boilers - 0.010 - 0.020 lb/ MMBtu

Wood-Fired Boilers

Particulate Matter Emissions
Top 50 Percent Figure 11



### Coal- Fired Boilers Fired Boilers

The NACAA PM data compilation, displayed in Figure 12, includes results for 67 coalfired units. These results are similar to the PM r esults for wood-fired units. EPA’s limits for solid-fueled units apply to this subcategory as the y did to the wood-fired subcategory. Approximately one-third of existing units tested wo uld not meet EPA’s vacated limit for existing large, solid-fueled boilers. Some portion of the remaining units would fall into EPA’s small- or limited-use subcategories, while others m ight be exempt under one of the riskbased exemptions. Accordingly, it is likely that on ly a minor percentage of coal-fired ICI Boilers units would have been required to reduce me tal HAPs under the vacated EPA
standard.31 Coal-Fired Boilers

Particulate Matter Emissions

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67

Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu)

EPA - Existing Large Boilers - 0.07 lb/MMBtu EPA - Limited-Use Boilers - 0.21 lb/MMBtu

EPA - New Boilers - 0.025 lb/MMBtu NACAA Range - Existing Boilers - 0.008 - 0.012 lb/ MMBtu Figure 12

As Figure 13 shows, NACAA’s calculation of the “av erage of the top 12 percent” for coal-fired boilers was 0.005 lb/MMBtu. After inco rporation of a variance factor, the NACAA recommended range for a MACT floor is 0.008 to 0.01 2 lb/MMBtu of PM.32 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Emission Units - Rank Order of Performance (Top 50 Percent)Emission Rate (lb/MMBtu) Avg of Top 12 Percent - 0.005 lb/MMBtu

NACAA Range - Existing Boilers - 0.008 - 0.012 lb/ MMBtu Coal-Fired Boilers

Particulate Matter Emissions
Top 50 Percent

EPA - New Boilers - 0.025 lb/MMBtu Figure 13

If this range is adopted by permitting authorities , one would expect that 15 to 25 percent of existing sources would comply without ta king further steps. NACAA believes this result is consistent with the data, with the associ ation’s understanding of the emissions profile of the subcategory and with the statute.



## Hydrogen Chloride

The vacated rule contained the following HCl emiss ion limits:

New solid

- fuel units (all) 0.02 lb/MMBtu New large, liquid

- fuel units 0.0005 lb/MMBtu

New small and limited

- use

- liquid fuel units 0.0009 lb/MMBtu Existing large solid

- fuel units 0.09 lb/MMBtu

EPA’s HCl MACT floor analysis for existing existing existing solid-fired units was based on 21 test results for eight ICI Boilers deemed to have contro l devices that were present on 12 percent or more of the units in this subcategory for which EPA had such information. NACAA agrees with EPA’s determination that acid gas scrubber tec hnology is employed in enough units within the wood-fired subcategory that the MACT flo or should be at least as stringent 37 as the performance expected from these technologies. However, EPA’s treatment of the

37 The Courts have made it clear that if a unit achie ves a lower emission rate without employing a parti cular technology it must be included in the calculation o f the MACT floor.33

emissions data resulted in an EPA limit for units t hat employ these technologies that is five to 50 times higher than it otherwise should be.

The first questionable decision is the way EPA tre ated a key test result that appears to have been an outlier. EPA reported that the ave rage of the 21 test results of eight units in the agency’s database was 0.0096 lb/MMBtu 38 . In this calculation EPA included a single test result that was six and 30 times higher, respe ctively, than the other two tests for that unit and an order of magnitude higher than the aver age of the data set. Recognizing that this result was an outlier, EPA did not include thi s result in its subsequent analysis of variability (see below). This one test result is s o much higher than the other 20 tests in the data set that its inclusion raised the average of t he data set by 70 percent. At a minimum, this test result should have been reviewed, and a r eason for the extremely high emission rate determined, before being incorporated in the a verage. Since EPA excluded this datum from the variability analysis, it should also have been excluded from the calculation of the
average.

The second technically questionable decision is EP A’s use of non- standard statistical calculation procedures to determine the variability of emission unit performance. For four of these nine units, EPA had two or more test results. Rather than employ standard statistical techniques, EPA defined a “variability factor” to b e the average of the ratio between the highest and lowest test result for each of these fo ur units. EPA then multiplied the average of the test results (0.0096 lb/MMBtu) by this very large variability factor (9.08) to determine the limit of 0.09 lb/MMBtu 39

.

It should be noted that in this process EPA was no t examining the variability that a given unit with a given fuel supply might experienc e if retested for compliance purposes. Instead it looked at the variability that might resu lt if a source burned a different mix of fuels. In the majority (18 of 22) of the tests rel ied on by EPA, the boiler combusted an undefined mix of fuels, including fuels (gas and li quid non-fossil fuels) from different subcategories, which would be expected to have diff ering emission levels. None of the testing for the four sources EPA used to generate i ts variability factor for solid fuels appears to be limited to coal, wood or solid fuel. Moreove r, the variability between testing was greatest in the cleanest units 40 and it is only when this variability is multiplied by an average that includes units with substantially higher emiss ions does the result approach EPA’s limit.

For example, one of the units in EPA’s group, when tested using as many as seven different combinations of fuels, emitted between 0. 000236 lb/MMBtu and 0.00534 lb/MMBtu of HCl. While variable, each of these res ults is far less than the resulting EPA limit. Nonetheless, EPA’s non-standard approach re sults in a calculated variability factor of

38 See, Memorandum: Re-Revised MACT Floor Analysis for the Industrial, Commercial, and Institutional Boilers
and Process Heaters National Emission Standards for Hazardous Air Pollutants Based on Public Comments, AppendixC-3 Calculation of HCL Emission Limits for Large Solid Fired Unit, EPA-OAR-2002-0058-0659.

39 Where the control device achieves on the order of a 90-percent reduction, applying a multiplier of ni ne to the
“controlled” emission rate has the effect of settin g the standard at the level of uncontrolled units.

40 EPA’s calculated variability factor for a “clean” unit (0.0017 lb/MMBtu average emission rate) was 22 .6, whereas another unit’s emissions were substantially higher (0.0098 lb/MMBtu average emission rate), bu t its EPA calculated variability factor was only 1.07.34

22.6 for this unit. This emission factor for this unit contributed to the large variability factor that EPA subsequently applied to the higher average emission rate for the subcategory. Applying standard statistical techniques yields a v ariability factor of 2.65, which NACAA
believes is a more reasonable estimate of variance than that which resulted from EPA’s method. Similarly, recalculating the EPA variance factor employing standard statistical
methods reduces the variance factor for the a secon d unit in that group from 14.3 to 2.53. Recalculating the entire EPA data set in this fashi on yields a variability factor of 2.68. This figure is at the upper bound of NACAA’s calculated variance factor range of 1.5 to 2.5, but is reasonable since the data set includes testing usin g a mix of fuels from different subcategories.

Correcting for each of the two questionable calcul ation decisions reduces the MACT floor emission limit for HCl for existing existing existing solid-fired boilers from 0.09 lb/MMBtu to a range of O.015 to 0.025 lb/MMBtu. This result is consistent with the MACT floor determined by
evaluation of the NACAA data set.

An additional questionable analytical technique is found in EPA’s calculation of the variability factor for new

solid-fuel boilers. Rather than employ the var iability factor it had calculated for existing

existing existing units, EPA chose to ignore these data and generate a variability factor
based on the ratio of chlorine content in coal. Th e resulting factor of 181 (18,100 percent) is so high that it renders the new source MACT floo r useless. EPA offers no justification as to why the variability factor it had determined based on emission reduction performance of existing units should not be employed. EPA does no t discuss or analyze whether the sampling processes associated with the fuel data in volve an averaging period or are instantaneous “grab” samples that may be more varia ble than emissions averaged over a three-hour period. EPA acknowledges that it employe d its technique in an attempt to ascertain what emission performance is achievable w ithout consideration of cleaner fuels. In its recent decisions, the U.S. Court of Appeals has determined that, in setting MACT floors, the appropriate inquiry is the level of performance that has been achieved by the bestperforming 12 percent, not the level that is achiev able without cleaner fuels.



### Wood- F ired Boilers ired Boilers

Figure 14 illustrates NACAA’s data set of 11 tests of wood-fired boilers where only a single fuel was employed during testing. These dat a show that all 11 existing wood-fired boilers would currently meet EPA’s vacated limit fo r existing sources and seven of the 11 existing sources would meet EPA’s standard for new sources.35 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1

1 2 3 4 5 6 7 8 9 10 11 Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu) Wood-Fired Boilers
Hydrogen Chloride Emissions

EPA - Existing Large Boilers - 0.090 lb/MMBtu

EPA - New Boilers - 0.020 lb/MMBtu Avg of Top 5 Boilers - 0.004 lb/MMBtu NACAA Range - Existing Boilers - 0.006 - 0.012 lb/M MBtu Figure 14

The average of the test results for the best-perfo rming 12 percent of the wood-fired units for which NACAA has information is 0.004 lb/M MBtu. After applying a variability factor, the limited data indicate that the existing source MACT floor would be determined to be in the range of 0.006 to 0.012 lb/MMBtu. Six of the 1 1 units in the data set comply with the limits in this range.



### Coal- F ired Boilers ired Boilers

The NACAA data set included HCl emissions data for 14 existing coal-fired ICI Boilers. See Figure 15. Thirteen of these boilers currently meet EPA’s limit for existing boilers and five of these units currently emit less than EPA’s limit for new boilers. Thus, it can be seen that the EPA methodology led to a result that is in consistent with the Congressional intent that a substantial number of existing units should be required to take some steps to reduce
HAP emissions.36 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

1 2 3 4 5 6 7 8 9 10 11 12 13 14 Emission Units - Rank Order of PerformanceEmission Rate (lb/MMBtu) Coal-Fired Boilers
Hydrogen Chloride Emissions

Avg of Top 5 Boilers - 0.010 lb/MMBtu NACAA Range - Existing Boilers - 0.015 - 0.030 lb/M MBtu

EPA - New Boilers - 0.020 lb/MMBtu EPA - Existing Boilers - 0.090 lb/MMBtu Figure 15

The average emission rate of the best performing f ive coal-fired ICI Boilers is 0.010 lb/MMBtu. After applying the variability factors, the limited data set indicates that the MACT floor for HCl emissions in the coal-fired subcatego ry is from 0.015 to 0.030 lb/MMBtu. Five of the 14 units in the data set currently meet this range.



### Oil - F ired Boilers ired Boilers

EPA had no HCl emissions data for liquid-fired ICI Boilers and so determined the MACT floor by calculating an emission level assumin g that all of the chlorine in the fuel was
converted to HCl. EPA had chlorine content data fo r seven sources, but rather than set the existing source MACT floor on the average of the be st-performing five sources, as required by the statute, EPA used the worst-performing unit in its data set. Applying EPA’s calculation methodology to the average of the top five performe rs in that database provides a MACT floor for existing, liquid-fired sources of 0.006 l b/MMBtu, rather than 0.009 lb/MMBtu.

NACAA’s data set for liquid-fired boilers contains emission test results for only three units -- 0.0007 lb/MMBtu, 0.0005 lb/MMBtu and 0.16 lb/MMBtu. While limited, these data are consistent with the best-performing units in EP A’s data base.37



### Additional Data

There are two potential data sources that merit di scussion. The first is emissions information provided to permitting authorities by s ources that intended to assert the “healthbased alternate compliance option” (risk-based exem ption) for acid gases contained in EPA’s rule. NACAA understands that EPA had, at one time, intended to maintain a database of test results for such sources, but has not done so as of this date. However, at least one
state has HCl emissions data for such sources. The se data are contained in the background materials for this Permit Guidance posted by NACAA, but have not been considered as a valid data set for establishing a MACT floor, since they appear to be biased towards the highest emitting sources that could not meet EPA’s limit.

The second potential source is EPA’s initial datab ase. In its MACT floor analysis, EPA had ignored test results in that database showing v ery low emissions because no specific pollution control device was identified. 41 Accordingly, one could attempt to use the best performing boilers in that database in calculating a MACT floor. However, unlike NACAA’s data collection effort, which attempted to gather a ll emissions information from all sources, the EPA effort appears to have been focused on asce rtaining the emissions performance of
those sources with the most effective controls. Th is resulting data set appears to be biased towards the cleanest units in the category. 42 Thus, using this data set in this way may focus on the “best of the best,” rather than the average of the best-performing 12 percent of all existing units. While the CAA does not require eit her EPA or a permitting authority to obtain additional information when developing rules or per mits under section 112, NACAA believes that a fair inference of Congressional intent is th at the data set for determining the MACT floor should be representative of the subcategory a s a whole. Even though they may not be representative of the emissions profile of the subc ategory, the EPA data do establish that
well-controlled units can meet the MACT floors reco mmended in this Model Permit
Guidance.



## Mercury

EPA’s data base contains mercury emissions data on 10 solid-fired units (six coalfired units and four units that burned wood or mixe d fuels during the testing). EPA’s analytical approach was similar to that employed fo r HCl and contains some of the same flaws. However, the data set did not contain outli ers and so the effects of EPA’s approach were not as significant. The average of these unit s was 3.02 pounds per trillion BTU (“lb/TBtu”) and the agency-determined variability f actor 43 was 2.98. The average of the top five coal-fired units was 3.20 lb/TBtu, while the a verage for the top 4 wood-fired units was 2.58 lb/TBtu. From these data, EPA set the existin g unit MACT floor at 9.00 lb/TBtu. The best-performing unit in EPA’s data set was a coal-f ired unit whose emission rate was 0.230

41 These data are incorporated in the background mate rial for this Permit Guidance posted on the NACAA

website.

42 NACAA is encouraging EPA to engage in broad, unbia sed, emissions data-gathering as it prepares to dev elop
a standard for ICI Boilers.

43 EPA again employed the average of the ratio of hig hest-to-lowest result rather than standard statisti cal rechniques.38

lb/TBtu. The best-performing wood-fired unit in th is data set had an emission rate of 0.266 lb/TBtu. Rather than using the variability factor determined from testing of existing units, EPA used the ratio of the highest to lowest mercury content in its fuels data base. In this instance the fuels content ratio was 12.54 (1,254 p ercent) and the new source mercury limit in the EPA proposed rule was set at 3.00 lb/T Btu.



### Wood- F ired Boilers ired Boilers

The NACAA data for ICI Boilers that were tested wh ile combusting only wood or other non-fossil solid fuels (such as bagasse) are presen ted in Figure 16. All eight of the boilers tested would comply with EPA’s limit of 9.00 lb/TBt u, while seven of the eight existing units would meet EPA’s new source limit of 3.00 lb/TBtu. Based on these data, EPA’s vacated rule would not have reduced mercury emissions from wood-fired boilers.

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00

1 2 3 4 5 6 7 8
Emission Units - Rank Order of PerformanceEmission Rate (lb/TBtu) Wood-Fired Boilers

Mercury Emissions

Avg of Top 5 Boilers - 1.65 lb/TBtu NACAA Range - Existing Boilers - 2.50 - 4.50 lb/TBt u Figure 16

EPA - New Boilers - 3.00 lb/TBtu

The average performance of the best performing five wood-fired ICI Boilers in the NACAA database was 1.65 lb/TBtu. When adjusted for variability, these data suggest a MACT floor of 2.50 to 4.50 lb/TBtu. The fact that almost all of the existing units would meet this floor is likely reflective of the limited numbe r of tests in the NACAA data set. The median performance of the best performing boilers c ombusting wood in EPA’s data set is substantially lower than these figures (approximate ly 0.5 lb/TBtu).39



### Coal- F ired Boilers ired Boilers

The NACAA data set contains mercury emissions data on 10 coal-fired ICI Boilers. The data set did not distinguish between types of c oal. As illustrated in Figure 17, all of the boilers in the NACAA data set would comply with the EPA limit for existing sources, while between 60 and 90 percent would meet a MACT floor b ased on NACAA’s data and 20 percent would meet a MACT limit based on the antici pated median performance of MACT technologies.

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00

1 2 3 4 5 6 7 8 9 10

Emission Units - Rank Order of PerformanceEmission Rate (lb/TBtu) Avg of Top 5 Boilers - 3.15 lb/TBtu EPA - Existing Boilers - 9.00 lb/TBtu Coal-Fired Boilers
Mercury Emissions

NACAA Range - 4.50 - 7.50 lb/TBtu

EPA New Units - 3.00 lb/TBtu Figure 17

The average mercury emission rate of the five best -performing coal-fired boilers was 3.15 lb/TBtu, while the median emission level for “ best-performing” units in EPA’s data set was 1.14 lb/TBtu. Applying the NAACA variability f actor to the limited NACAA data set yields a MACT floor of between 4.50 lb/TBtu and 7.50 lb/TB tu, while establishing a MACT limit on the basis of the median performance of the “best of the best” would yield a limit of between 1.50 and 3.00 lb/TBtu.40 

# C C ontrol Strategies ontrol Strategies ontrol Strategies – Techniques and Costs

Techniques and Costs Techniques and Costs

CO Control for Organic HAP Reduction

For the past several decades, air pollution contro l efforts have focused on SO 2 , NO x , Volatile Organic Compounds (“VOC”) and PM emissions . Nearly all of the country has been in compliance with the CO National Ambient Air Qual ity Standard (“NAAQS”) for many years,
and for most sources CO emissions are well below NA AQS-driven permit limits. For this reason, CO is the “forgotten” criteria pollutant. For NAAQS purposes, sources typically do not need to take specific steps to reduce CO and are not concerned that a stack test for CO will show a violation of a NAAQS-based limit. Not withstanding the lack of need for a focus on CO emissions over the years, combustion technolo gy has advanced (perhaps because more complete fuel combustion represents improved e fficiency that reduces manufacturing costs) to the point where very low CO emissions (in the range of 1 ppm) are generated by a substantial portion of sources that combust gaseous or liquid fuels.

NACAA recognizes that sources whose current emissi ons may be greater than the association’s recommended ranges may be concerned t hat the cost of compliance with limits within the recommended ranges may be high. We do not believe this is likely to be the case, since, unlike SO 2 , NO x and PM control, effective CO control is ordinarily achieved by managing the combustion process better (and thereby lowering operating costs) than by post-combustion controls. Moreover, NACAA’s data s uggest a continuum of emissions performance within the fleet – a substantial number of sources will require only modest reductions in emissions, while some sources will ne ed to dramatically reduce emissions to meet the recommended emission limits. Accordingly, NACAA suggests the following hierarchy of control measures for sources that need to reduce CO emissions to meet recommended ranges.

1. Install a continuous CO monitor – NACAA believes th at a continuous CO monitor should be considered part of the control system for all sources larger than 50 to 100 MMBtu/hr. NACAA also recommends the use of such mo nitors at sources whose CO emissions are variable and potentially large, such as sources that combust wet wood. Use of a continuous CO monitor over a period of tim e will assist the operator and permitting authority in understanding those combust ion practices that lead to excessive CO emissions and in identifying those spe cific measures that will reduce
CO emissions in the most cost-effective manner. Co ntinuous CO monitors typically cost in the range of $50,000 to $65,000, with insta llation costs of $10,000 to $15,000. Periodic monitoring with portable hand-he ld monitors is likely to be a costeffective technique for smaller sources.41

2. “Tune up” the unit for CO purposes, including clean ing the system, servicing or replacing filters and maintaining induced draft fan s, to insure that the air flow to the boilers is optimized. Consider adding process para metric monitoring devices, such as oxygen, flow, moisture and mass air sensors.

3. Manage fuel supplies to reduce moisture and variabi lity, including (as necessary) establishing maximum moisture content and minimum h eat content for solid fuels.

4. Blend fuels as necessary to maintain relatively con stant heat and moisture inputs.

5. Evaluate the fuel delivery system to ensure that va riability in fuel delivery rates is

minimized.

6. Evaluate replacing burners. NACAA believes that fo r most units, this step, in conjunction with the above measures, should result in compliance with the NACAArecommended ranges. The Ozone Transport Commission has estimated that replacing burners at a 250MMBtu/hr boiler would cos t between $200,000 and $3,000,000. As necessary, retain a combustion expe rt to evaluate the process at a troublesome unit and suggest improvements.



## PM Control for Metal HAP and Mercury Reduction

NACAA’s data suggest a continuum of performance wh ere a number of sources with existing PM control devices will merely need to “tu ne up” or upgrade existing equipment and/or improve operating practices. For those sour ces, NACAA recommends the techniques identified above for CO reduction. As part of the implementation of the PM 2.5 NAAQS, state and local agencies are including condensable pollut ants, such as sulfur trioxide

, when defining and establishing PM emission limits at a s ource. Additional controls, including sorbent injection, “wet” scrubbers and ESPs are eff ective at reducing PM emissions. Continuous PM and mercury monitors can be useful in assisting the operator in managing the combustion process and in tracking compliance.

For most solid-fuel boilers that need to control P M and mercury, activated carbon injection, perhaps utilizing brominated carbon or o ther additives, and the installation or upgrade of an ESP or fabric filter will be the solu tion of choice. NACAA believes that for most wood-fired sources that need to upgrade their PM controls, a fabric-filter system will be
the most cost-effective solution because of its low er capital cost and high level of performance in controlling the smaller particulate matter that is normally associated with
metal HAP emissions.

Additional details concerning PM and mercury contr ols are provided in NACAA’s, Controlling Fine Particulate Matter Under the Clean Air Act: A Menu of Options , and Regulating Mercury From Power Plants: A Model Rule for States and Localities . These reports are available on www.4cleanair.org (under “ Our Publications”). In addition, the42

Northeast States for Coordinated Air Use Management 44 (“NESCAUM”) is currently preparing a comprehensive detailed review of the expected cos t and performance of PM and acid gas control options for ICI Boilers. Permitting author ities are encouraged to consult this source
when it becomes available.

For oil-fired boilers that need to improve PM cont rol, there are several options that may be implemented, including switching to lower-su lfur fuel, updating atomizers and burners and injecting sorbents. Switching from hea vier-weight to lighter-weight oils can also achieve a significant reduction in PM emissions. U pdating atomizers and burners used in oil-fired boilers to reduce unburned carbon may pro vide additional PM reductions. Postcombustion control options for oil-fired boilers in clude wet scrubbers and ESPs.

Depending on the particular application and existi ng emissions control configuration, a dry electrostatic precipitator (ESP) or upgrade t o an existing ESP may be the control technology option of choice. Dry electrostatic prec ipitators are a proven technology for controlling particulate emissions from oil-fired bo ilers and have been installed on oil-fired boilers for more than 40 years. Dry electrostatic precipitators on coal- and oil-fired boilers are typically designed to achieve particulate emiss ion levels of between 0.01 and 0.03 lb/MMBtu. As a rule of thumb, for each additional field added to an ESP, an additional 50- percent PM reduction can be expected. Reducing PM emissions from an existing boiler from 0.08 lb/MMBtu down to 0.02 lb/MMBtu would likely req uire two additional fields to the ESP. The capital cost of an ESP can vary depending on th e number of treatment fields, inlet emissions and control requirements, and design chos en. Capital costs for a typical ESP applied to an industrial boiler would be in the ran ge of $200,000 to $1.5 million.

Most solid-fuel boilers that need to control PM an d mercury are likely to utilize an existing or retrofitted ESP or, where applicable, a dd a fabric filter. Activated carbon injection (“ACI”) and other sorbent systems are widely availa ble with growing experience with incinerators and utility boilers, and sorbents can be injected directly into the ESP or fabric filter. Slipstream testing of a boiler can help de termine the relative effectiveness of a sorbent prior to making a long-term commitment to th e system. Generally, activated carbon systems that are available for utility boilers are also available for industrial boilers and use the same equipment, including feeders, blowers and lances, and the sorbent is injected into either the ESP or the fabric filter. These systems typically have low capital costs and higher operation and maintenance costs. However, industri al boiler flue gas volumes are lower and a sorbent sack or pack may be employed in lieu of the silo used in utility boiler applications. Accordingly, the cost of ACI systems for industrial boilers will be on the order of a few hundred thousand dollars, compared to a range of es timated costs for large coal-fired power plants of between one and two million dollars.

There are a number of different forms of scrubbing technologies that are applicable to industrial boilers, such as wet scrubbers, sorbe nt injection, and furnace sorbent injection and dry or wet flue gas desulfurization technologie s 45 . The technology applied depends on the fuel type, existing control configuration and e missions control requirement. Wet

44 NESCAUM members include Connecticut, Maine, Massac husetts, New Hampshire, New Jersey, New York,
Rhode Island and Vermont.

45 Flue gas desulfurization (“FGD”) units are commonl y referred to as “scrubbers.”43

scrubbers, such as venturi scrubbers, are one of th e most common types of scrubbers applied to industrial boilers to control both PM an d acid gases. Wet scrubbers can achieve as high as 85 to 90 percent control of PM 10 but are less efficient with particle sizes less than 1 micron. For oil-fired boilers, venturi scru bbers are the most commonly applied wet scrubber design and are capable of removing some me rcury and metal HAPs. Capital costs for wet scrubbers for typical industrial applicatio ns can range from one hundred thousand to

two million dollars.

Wet electrostatic precipitators (“WESP”) are anoth er option that may be applied to existing oil-, wood-, and coal-fired boilers. WESP are more suited to capturing fine particles than a dry ESP. If a WESP were applied to an exist ing boiler with another type of particulate control device already in place, the WESP would be installed following the existing particulate control device. The size of the WESP r equired would be smaller in this instance than if it were the sole PM control device, as the upstream particulate control device would reduce the particulate loading entering the WESP. The advantage of installing a wet scrubber/WESP combination is that the scrubber will capture the acid gases and the WESP will be effective at removing acid mists, condensed metals, and other liquid droplets. The capital cost of a WESP can vary depending on the nu mber of treatment fields, inlet emissions and control requirements, and design chos en. Capital costs for a typical scrubber/WESP combination applied to an industrial boiler would be in the range of $300,000 to $2.6 million.

A combination of ESP/WESP or ESP/wet scrubber/WESP or wet scrubber/WESP is likely the most efficient system for controlling PM, mercury and metal HAPs. The use of such a combination of emissions control technologies is common where superior control of pollutants is sought. With such a control combinat ion, the first technology in the treatment train will typically remove the coarse particulate (PM 10 ), with the succeeding technologies addressing the final particulate (PM 2.5 ) and HAPs.



## Acid Gas Control for Acid Gas HAP Reduction

NACAA’s HCl emissions data are more limited than i ts CO and PM emissions data. NACAA agrees with EPA’s conclusion in other MACT st andards that a 90- to 95-percent reduction in emissions of HCl and hydrogen fluoride (“HF”) is attainable at reasonable costs with commercially available acid gas scrubbing equi pment commonly employed for SO 2 reduction. The most common way of controlling acid gas HAPs is likely to be the installation
of wet scrubbers. Venturi scrubbers are the most c ommonly applied wet scrubber for oilfired boilers. The capital cost of a typical wet s crubber for an industrial boiler would be between $100,000 and $2.1 million. Wet scrubbers m ay also be paired or integrated into a wet electrostatic precipitator (WESP) for existing oil-, wood-, and coal-fired industrial boilers for acid gas and metal HAP control. For this combi nation, the scrubber would be primarily designed to remove the acid gases and particulate a bove 2 microns in size while the WESP would serve to remove the fine particulate less tha n 2 microns.

HCl, as a major pollutant associated primarily with coal-fired industrial boilers, is not measured on a continuous basis, and difficult to me asure on a periodic basis. Fuel44

sampling and/or parametric monitoring of the post-c ombustion control device may be the preferred monitoring option.45 

# Establishing MACT Establishing MACT

The workgroup made a significant effort to develop a robust data compilation to aid in establishing a meaningful MACT floor. However, the CAA requires that the emission limit be based on MACT, not the MACT floor. Section 112( j) mandates that permitting authorities establish permit limits based on the maximum degree of reduction in emissions of the HAPs subject to section 112 that they determine is achie vable. NACAA believes that in the case of its CO and PM MACT floors, the data are sufficientl y comprehensive so that the MACT floor represents the level of emission reduction that wou ld represent MACT. However, with respect to HCl and mercury, both the NACAA data set and the subset of the ICCR data used by EPA to set its floor are so limited that they ma y not represent the emissions profile of each of the subcategories. In addition, there may be a number of unique facilities within this broad category of sources for which there is n o emissions information available to establish a MACT floor. In these circumstances per mitting authorities may need to conduct a case-by-case MACT analysis. Moreover, a permit d ecision could be challenged on procedural grounds if a permitting authority failed to consider whether any “beyond-thefloor” requirements are appropriate.

In evaluating whether MACT limits should be more s tringent than the floor, permitting authorities must consider the cost of ac hieving such emission reductions, and any non-air quality health and environmental impact s and energy requirements associated with such costs. MACT is not limited to post-combu stion controls, but includes any available pollution-reduction technique, including process ch anges, substitution of fuels or other system modifications, such as the enclosure of emis sion sources to capture fugitive emissions. MACT may include design, equipment, ope rational or work-practice standards and requirements for operator training and certific ation. Thus, for example, if open storage of solid fuels leads to uncontrolled variability in the moisture content of the fuel, subsequent incomplete combustion and high CO and organic HAP e missions, the permitting authority may establish a maximum moisture content for the fu el to be burned. Alternatively, the agency may establish a work practice or system modif ication, such as a requirement that
the solid fuel be “covered” in some fashion for a s pecified period of time before it is

combusted.

EPA has, in this and in other MACT standards, reje cted any “beyond-the-floor” controls as “too expensive,” but has not provided a ny rationale for its determination or any criteria that are of use in assisting permitting au thorities in making this evaluation. In the
Clean Air Interstate Rule 46 and the Clean Air Mercury Rule 47 , EPA has determined that the

46 EPA’s Clean Air Interstate Rule established a “cap and trade” emission reduction program for SO 2 and NOx. See, 70 FR 25162, May 12, 2005.46

same acid gas and mercury controls as would likely b e employed to comply with ICI Boiler MACT permits are “highly cost effective.” The gros s emissions of HAPs from any covered units will be several orders of magnitude less than emissions of criteria pollutants; however the risk to public health from such toxic emissions on a per-pound-of-emission basis may be much greater than for criteria pollutants. The fac t that Congress understood that unit costs of control for HAPs would be higher than criteria p ollutants is well documented in the legislative history and in the structure of the CAA itself. The major source threshold for HAPs is far lower for toxic air pollutants than for crit eria pollutants. Further, the Act requires a MACT limit for each unit at a major source that emi ts a HAP – regardless of size – and requires that all units that emit a HAP meet a MACT floor – regardless of cost. Against this background, it is unreasonable to suggest that in de scribing the MACT process Congress intended that controls for mercury, for example, sh ould be rejected as MACT unless mercury control costs (on a per-ton basis) were in the same range as criteria pollutant control costs.

Based on their experience over the years, permitti ng authorities have gained an understanding of the costs of control of criteria p ollutants. The figure that each state or local permitting authority employs for determining whether costs are too high under the BACT program is not based on the relative risk assoc iated with SO 2 emissions compared
with NO x emissions, but on the cost per ton of removal of t hat pollutant as generally experienced within the industry. Given the relativ e nature of the inquiry, there is no single cost figure that is considered “too high” for BACT for all criteria pollutants. Rather, in the BACT process permitting authorities look to determin e whether unique factors exist, such that costs at a particular facility are significant ly higher at the proposed facility than within the industry in general for the pollutant at issue.

The suite of controls for HAP emissions in the ICI Boiler category that is likely to be “achievable” should be familiar to permitting autho rities as it is the same set of controls employed throughout the country for reducing criter ia pollutants.

Under the “top-down” BACT process, the most effect ive control strategy that has been demonstrated in practice is to be employed unl ess the permitting authority determines
that it is “infeasible” at that source. When consi dering costs, NACAA recommends that permitting authorities also recognize the co-benefi ts associated with the reductions in PM (especially PM 2.5 ) and SO 2 that would occur from control of HAP metals and aci d gases.

Under this approach, a source would not need to em ploy “above-the-floor” controls if its HAP emissions were substantially less 48 than the emissions of its peers within the category (or subcategory) or if unique circumstance s of the facility design or location led to substantially greater costs for the pollution contr ol device or technique than would be experienced by other facilities within the subcateg ory.

47 The Clean Air Mercury Rule, 70 FR 28696, May 18, 2 005, attempted to establish a “cap ad trade” emissi on reduction program for mercury. This rule was found to be unlawful and vacated.

48 Presumably this could occur because of the specifi c design of the plant or by way of enforceable perm it limits on its fuel supply.47 

# Monitoring and Reporting Require Monitoring and Reporting Requirements ments

EPA’s implementing regulations at 40 CFR 63.52(h) specify that permits under section 112(j) must require enhanced monitoring in accordance with section 114(a)(3) of the CAAA. This monitoring must be capable of demon strating continuous compliance for each compliance period during the applicable report ing period and shall be of sufficient quality to be used as a basis for directly enforcin g all applicable requirements, including emission limitations. Similarly, EPA’s implementin g regulations state that the Title V permit must specify notification, operation and maintenanc e, performance testing, monitoring, reporting and recordkeeping requirements, as well as any production limits, operational limits or other requirements necessary to ensure pr actical enforceability of the MACT emission limitation and to ensure compliance with s ection 114(a)(3). See, 40 CFR 63.52(f)(2).

There are several types of PM emission measuring t echniques that may be applied to ICI Boilers depending on the specific application. One PM CEMS technology, beta attenuation-based systems, can be used for both wet - and dry-stack situations and the installed costs are in the range of $120,000 to $14 0,000. PM CEMs have been applied to coal-fired power plants with almost a dozen systems installed to date and more than a dozen required at recently permitted boilers. PM C EMs have also been applied to pulp mill recovery boilers, with one application having three years of operating data, and also applied to incinerators, with one application having two ye ars of data. A second PM measurement technology, optical-based technology, uses a light scattering technology for dry stacks. The installed costs are approximately $25,000 for the e quipment and another $20,000 to $40,000 to perform the stack test that develops the correlation curve to match instrument readings to the amount of particulate emissions.

In addition, bag leak detection systems can provide a cost-effective approach to ensuring proper operation of fabric filters. NACAA recommends that where bag leak detection systems are chosen, care be taken to set t he alarm at levels that will ensure compliance with PM limits necessary to comply with MACT requirements and that an appropriate response plan is incorporated in the pe rmit. EPA guidance on fabric filter operations can be found in a document entitled “Fab ric Filter Bag Leak Detection Guidance.” This document is available at http://www .epa.gov/ttnemc01/cam/tribo.pdf.

For metal HAPs, there are a few different methods for obtaining measurements. Monitoring options used on utility boilers are appl icable to industrial boiler applications. Periodic stack tests provide a basic form of measur ement but are limited in providing realtime process or compliance information, as well as limited in overall accuracy, as they will not necessarily account for the variability in fuel and other operating conditions that may be encountered during normal operation. Sorbent traps are a semi-continuous form of metal48

HAP measurement that places an activated carbon can ister in the flue gas stream to collect vapor phase mercury. The sorbent traps usually sam ple directly in the flue gas stream for four to 10 days, at which time they are removed and the trapped gases are analyzed to determine flue gas concentrations. Typical sorbent trap systems cost under $50,000 for capital equipment and installation, and approximate ly $35,000 for annual operation and maintenance of the system. Mercury CEMs provide th e highest level of accuracy and continuous reporting of emissions. There are more than 500 mercury CEMs currently being installed on utility coal-fired boilers. The same CEM technology could be applied to industrial boilers and cost between $120,000 and $1 40,000.

Fuel sampling may also be employed as a compliance -demonstration technique. Fuel analysis costs may be reduced by composite sam pling procedures. NACAA recommends that fuel sampling be conducted on an “a s combusted” basis. Specifically, NACAA recommends that coal sampling be conducted as the coal is on the conveyor system, rather than sampling the coal pile itself. Under s uch an approach individual daily samples could be taken, combined and homogenized over a mont h, and the composite sample analyzed monthly. Such an approach, coupled with r egular stack tests, could provide the required assurance of compliance at reasonable cost

.

CO monitors range in sophistication from hand-held portables up to full-system Continuous Emission Monitoring Systems (“CEMS”). O ther options include parametric monitoring and Predictive Emissions Monitoring Syst ems (“PEMS”). These devices typically cost as little as $1,000 for a portable CO monitor (non-continuous), up to $35,000 for a PEMS, and $35,000 to over $65,000 for a CEMs.

NACAA believes that a continuous CO monitor should be considered part of the control system for all sources larger than 50 to 10 0 MMBtu/hr. NACAA also recommends
the use of such monitors at sources whose CO emissi ons are variable and potentially large,
such as sources that combust wet wood or where a mi x of fuels, including sludge, is used. Periodic monitoring with portable hand-held monitor s is recommended for smaller sources. The need for such monitoring to ensure proper combu stion to minimize organic HAP emission and performance of post-combustion control devices is clear and was recently underscored by industry comments to the effect that reference method stack tests of
sources should not be used to set the MACT floor be cause such testing understates the
“real world” emissions of ICI Boilers.

Opacity limits greater than 5 percent are unlikely t o serve as an effective compliance mechanism because they will not ensure that the low PM emission rates required under the MACT limits are being met. Accordingly, NACAA reco mmends VE or COM monitoring for PM compliance only where opacity limits of 5 percent o r less are established.49 

# Incorporating M Incorporating MACT General Provisions

ACT General Provisions ACT General Provisions

EPA has developed a comprehensive array of “genera l provisions” intended to cover
administrative matters associated with MACT standar ds. See Subpart A of 40 CFR Part 63. The agency has recognized that some of these provis ions may not be appropriate for each promulgated MACT standard. Accordingly, EPA’s prac tice has been to list the provisions of the Part 63 requirements that it intends to apply f or a specific MACT standard in the final rule for that standard. The listing of general pro visions that EPA had intended to be applicable to the vacated ICI Boiler MACT is publis hed as Table 10 to Subpart DDDDD of Part 63, 69 FR 55277, September 13, 2004. NACAA ha s reviewed this listing and disagrees with EPA in three instances where the agency intend ed to waive applicability of certain of the
General Provisions:

1. EPA’s vacated rule would have waived 40 CFR 63.6(h) (4) and (h)(5), 49 40 CFR 63.7(b)(1) and 40 CFR 63.9(e) and (f), which call f or prior notification of the anticipated date of conducting performance tests an d opacity or visible emission (“VE”) observations required under the standard. P ermitting authorities should
decide whether and under what circumstances such no tification should be provided. NACAA recommends that, at a minimum, pri or notice of all performance tests, other than opacity/visible emission observat ions, as well as the initial demonstration of compliance with any opacity or vis ible emission requirements, be required. NACAA also recommends incorporation of 40 CFR 63.6(h)(6), which requires that records of the conditions during VE o bservations be retained and made available to the permitting authority on reque st.

2. EPA’s vacated rule would have waived several provis ions relating to maintenance and operation of Continuous Monitoring Systems (“CM S”). NACAA recommends
retention of the General Provisions found at 40 CFR 63.8(c)(4) (CMS must be operating at all times, except during breakdown, ex empt operations, repair, maintenance and high-level calibration drift) and a t 40 CFR 63.8(g)(5) (data collected during these out-of-calibration events ma y not be used in determining emissions from the facility). NACAA also recommend s that, unless specific data are provided demonstrating the lack of need for or infe asibility of such provisions in a particular situation, the daily calibration and cyc ling requirements of 40 CFR 63.8(c)(4)(ii) and (c)(6) be retained.

49 EPA also would have waived 40 CFR 63.6(h)(5)(ii), which requires a minimum of three hours of observat ion for the initial compliance demonstration of any vis ible emission or opacity requirement. NACAA believ es this requirement is reasonable for the initial complianc e demonstration and recommends that this requiremen t be incorporated in any MACT permit that provides for o pacity as a means of demonstrating compliance with a PM

limit.50

3. EPA’s vacated rule would have waived 40 CFR 63.9(c) (7)-(8), which requires sources that are required to employ a CEM to report periods of excess emissions and parametric monitoring exceedances and 40 CFR 63 .10(e)(3), which requires semi-annual reporting (unless more frequent reporti ng is required on a case-bycase basis or the frequency is reduced by the permi tting authority) of excess emissions and parameter monitor deviations. NACAA recommends that any MACT permit include provisions requiring all sources, in cluding but limited to sources with CMS, to provide prompt reports of periods of excess emissions and parametric monitoring exceedances. NACAA further recommends t hat such excursions be clearly identified as violations of the permit unle ss such parameters are part of a Compliance Assurance Monitoring (“CAM”) plan 50 and are not correlated with the
emission limit.

EPA’s vacated rule identified several of the Gener al Provisions that do not appear to be applicable to or appropriate in the current situ ation. NACAA recommends that case-bycase MACT permits state that the General Provisions of 40 CFR Part 63 apply, as modified in response to the previous discussion, except for

1. 40 CFR 63.6(h)(2)(i), which provides that if a stan dard does not state a test method for opacity/VE standards, Method 9 (opacity) and Me thod 22 (VE) shall be employed. Many states employ other methods and NAC AA recommends that in any such instance the permit identify the compliance me thod;

2. 40 CFR 63.6(h)(7)(ii), which authorizes a source to submit Continuous Opacity Monitor (“COM”) data in lieu of Method 9 data, wher e the standard requires Method 9. NACAA supports the use of COM data, but believes that in case-by-case permitting under section 112(j), the compliance met hod should be specifically identified;

3. 40 CFR 63.7(a)(2)(ix), which applies only to new or reconstructed sources and so is not applicable here;

4. 40 CFR 63.8(b)(1)(iii) and 63.11 having to do with flares; and

5. 40 CFR 63.8(f)(6) and 63.10(b)(2)(xiii) relating to procedures employed by the Administrator in approving relative accuracy tests for CEMs.

50 EPA’s regulations concerning CAM plans are found at 40 CFR Part 64.51 

# Determining a Compliance Date for Each Facility Determining a Compliance Date for Each Facility

Each case-by-case section 112(j) permit must estab lish a compliance date by which the owner or operator is required to be in co mpliance with the MACT emission limitation and all other applicable terms and condi tions of the permit. See, 40 CFR 63.52(f). Under section 112(i) the schedule for co mpliance with MACT standards is to be “as expeditiously as practicable,” but not later th an three years after the effective date of

the standard. The statute authorizes an additional extension of one year, where necessary, for the installation of controls.

In a number of instances, sources that were subjec t to the vacated rule will have installed controls and made plans to comply with th e EPA rule. In other instances, particularly where CO levels at natural gas-fired u nits are at or near levels determined necessary to control organic HAPs, no additional co ntrols may be necessary and so a reasonably prompt compliance date would appear to b e required. In yet other instances the full statutory time period may be required for a source to comply.

While individual source factors may lead to differ ent time frames for installation of emission controls or pollution prevention devices, NACAA believes the following schedules are reasonable for installation, shakedown and compl iance testing for the identified actions:

1. Install continuous emission monitors, implement a p eriodic CO monitoring program or optimize combustion for CO reduction – six to 12 months;
2. Install new burners, add carbon injection where the re is an existing fabric filter or upgrade existing PM controls – 12 to 18 months; and
3. Replace the firebox or the entire boiler or install a fabric filter, electrostatic precipitator or acid gas scrubbing system – three y ears.

Note that under 40 CFR 63.7, where a performance t est is required, it must be conducted within 180 days of the compliance date se t out in the permit.52 

# Reasonable Processes and Procedures for Case Reasonable Processes and Procedures for Case-

by - Case MACT Determinations Case MACT Determinations Case MACT Determinations

While the CAA calls for “case-by-case” determinatio ns of MACT standards and floors for each subcategory, individual facility reviews m ay be burdensome and unnecessary in many instances. For example, the recommended organ ic HAP controls for many natural gasfired industrial boilers are a level of CO control and monitoring to ensure complete combustion of the organic HAPs. Given the anticipa ted congruence of performance and costs within this subcategory, some states with lar ge numbers of nearly identical sources may wish to develop a “permit by rule” to minimize transaction costs within industry and avoid a waste of scarce permit authority resources. Such an approach would likely need to incorporate a “safety valve,” where a source could request a specific facility review in order to meet the statutory requirement of a “case-by-cas e” review, but would otherwise appear to be a reasonable approach that should be welcomed by all parties. In evaluating whether to pursue one or more permits “by rule,” the amount of time needed to promulgate new rules should be considered, as the 18-month deadline for issuing case-by-case permits would appear to apply.

Technically, the ICI Boiler category is the “fuel combustion category” and includes combustion turbines, reciprocating internal combust ion engines, engine test facilities and rocket test facilities, as well as boilers and proce ss heaters. See, 67 FR 16582, April 5, 2002. If the permitting authority encounters a sit uation where the subcategories set out in this Permit Guidance do not appear to be applicable because of legitimate technical differences that distinguish the source from others in the subcategory, it should consider establishing a new subcategory. Ordinarily, this w ould involve ascertaining a MACT floor and
MACT.



## De Minimis Exemptions

Exemptions

The federal Courts have interpreted the CAA as gen erally authorizing de minimis exemptions or exemptions based on administrative ne cessity. This notion is based on the principle that "the law does not concern itself wit h trifling matters." Alabama Power Co. v. Costle, 636 F.2d 323, 360 (D.C. Cir. 1979)

. However, a de minimis exemption "is not an ability to depart from the statute, but rather a to ol to be used in implementing the legislative design." Id

. Unsupported assertions are not ordinarily suffici ent and a de minimis exemption is not available if it is contrary to the intent of the statute 51 . In Natural Resources Defense

51 See, e.g., Public Citizen v. Young, 831 F.2d 1108, 1122 (D.C. Cir. 1987) (rejecting ag ency's attempt to

create a de minimis exemption for certain chemicals that caused cancer in animals but posed only minuscule risk to humans, because statute barred listing of c hemicals causing cancer "in man or animal"); Sierra Club v. EPA, 992 F.2d 337, 343-45 (D.C. Cir. 1993); Kokechik Fishermen's Ass'n v. Secretary of Commerce

, 839 F.2d 795, 801-02 (D.C. Cir. 1988). The Court further hel d that "there is likely a basis for an implication of de
minimis authority to provide [an] exemption when the burde ns of regulation yield a gain of trivial or no valu e." Alabama Power, 636 F.2d at 360-61; see also Public Citizen v. FTC, 869 F.2d 1541, 1556-57 (D.C. Cir. 1989) (doctrine permits exemptions when application of st atute would have no benefit, not merely when agency concludes that costs exceed benefits). Additionall y, the Courts have held that "the literal meaning o f a statute53

Council, Inc. v. EPA, 966 F.2d 1292, 1306 (9th Cir. 1992), the Court rej ected a de minimis exemption because of "lack of data" to show that reg ulation would be of "trivial or no value."

De minimis exemptions are not available if they are contrary to the structure of the MACT program or if they result in more than a trivi al increase in emissions. Permitting
authorities should consider the use of this authori ty to prevent absurd or futile results as they encounter unique situations. NACAA is recomme nding two exemptions that have been incorporated in the Permit Guidance, based on the n otion of a de minimis exemption:

1. The Permit Guidance does not establish MACT floors or MACT emission limits for PM, HCl or Hg for gas-fired boilers. While such boiler s emit some amount of these pollutants and a “best performing 12 percent could be identified,” the amount of

additional HAP reductions that would be obtained is truly trivial.

2. The Permit Guidance recommends an exemption from al l regulation for small hot water heaters that may be used for “domestic purpos es” at facilities subject to regulation. Again, we believe this exemption is co nsistent with the structure and
intent of the CAA and will not lead to a measurable increase in HAP emissions at any facility.



## Risk- B ased Exemptions ased Exemptions

Section 112(d)(4) of the CAA provides:

“With respect to pollutants for which a health thr eshold has been established, the Administrator may consider such th reshold level, with an ample margin of safety, when establishing emission standards under this
subsection.”

Based on this provision, EPA's vacated rule adopte d two “risk-based exemptions 52 ” from MACT – one for HCl, the other for manganese (“ Mn”). After careful review, NACAA has concluded that these exemptions are not authorized by the CAA, are not technically sound and are not in the public interest. Therefore, thi s Permit Guidance does not provide for or recommend the incorporation of risk-based exemption s in permits issued under section 112(j).

We note that the factual predicate for t he use of section 112(d)(4) for acid gas HAP
and metal HAPs – the establishment of a health thre shold for each of these pollutants – has not been met. Congress authorized risk-based stan dards only

need not be followed where the precise terms lead t o absurd or futile results, or where failure to all ow a de

minimis exemption is contrary to the primary legislative g oal." Id

, at 1535. Because EPA's regulation avoided a "mammoth monitoring burden" and yet "square[d] with the health-protective purpose of the statute," the Court concluded that to require a different result would be "to adjudge Congress incompetent to fashion a ra tional legislative design." Id

. at 1534-35.

52 In the final rule EPA described these exemptions a s “health-based compliance alternatives.”54

“where health thresholds are well-established...and t he pollutant presents no risk of other health effects, including cancer, for which no threshold can be
established 53 ....”

As identified in Appendix 4, many of the HAPs withi n these categories are potential or demonstrated carcinogens. Because no meaningful st udies have been conducted, EPA has identified both HCl and manganese as unclassifiable for carcinogenicity. For this reason it

cannot be asserted that a “well-established” thresh old exists and that there is no risk of

cancer.

Moreover, EPA’s Integrated Risk Informat ion System (“IRIS”) reports that no studies have identified a No Observable Effects Level (“NOE L”) for neurological effects for
manganese 54

. Further, the CAA requires that a section 112(d)(4) standard include “an ample margin of safety.” EPA’s IRIS report conclud es that the scientific confidence in the Oral Reference Concentration for HCl employed by EP A in the ICI Boiler “risk-based exemption” is “low. 55 ” For this reason, it cannot be said that the “wel l established” threshold that provides an “ample margin of safety” has been established for HCl.

EPA has acknowledged that these “exemptions” are no t “emission standards” for a category or subcategory under section 112(d)(2) but “alternative standards for individual sources that demonstrate eligibility.” EPA Brief. at 55. 56 Such alternative emission standards are authorized under section 112 only for sources that meet the early reduction requirements of section 112(i)(5). Broader approac hes for alternate emission standards were specifically rejected by Congress in the devel opment of section 112. 57

Whatever authority EPA may have under section 112( d)(4) was not delegated to state and local permitting authorities under section 112( j). The CAA distinguishes between the Administrator’s authority to set nationwide standar ds (reserved to the Administrator) and the authority to issue individual permits where a natio nwide standard has not been issued (provided to “the Administrator 58 [or the State]”). See, sections 112(j) (4) and (5 ).

53 S. Rep. No. 228, 101st Cong. 1st Session, (Decembe r 20, 1989), reprinted in A Legislative History of the
Clean Air Act Amendments of 1990 (Comm. Print 1993), at 8511.

54 See, http://www.epa.gov/iris/subst/0373.htm; http: //www.epa.gov/ncea/iris/subst/0396.htm.

55 The IRIS report concludes “[t]he chronic study use d only one dose and limited toxicological measureme nts. The supporting data consist of two subchronic bioas says; the database does not provide any additional chronic or reproductive studies. Therefore, low confidence was recommended for the study, database, and the Rf C”.

56 Initial Brief of Respondent United States Environme ntal Protection Agency, No. 04-1385, September 18,
2006.

57 Congress specifically rejected an amendment that wo uld have provided that individual sources “could co mply
with alternative emission limitations in lieu of st andards under this section, if the owner or operato r presents
evidence sufficient to demonstrate that emissions f rom the source in compliance with such limitations present a negligible risk to public health under criteria i ssued by the Administrator.” 2 Legislative History, at 3939. The Act itself provides a specific alternative emission standard for coke oven batteries. Thus, a risk-ba sed exemption for specific sources is contrary to the s tatutory structure and would not be approved under a de

minimis test, even if the emissions impacts were trivial.

58 There may be instances where EPA manages the Title V program (e.g., on Indian lands) and is obligated to issue the section 112(j) permit.55

Section 112(j) does not contain language authorizi ng states to develop risk-based
standards. While it does reference the alternate e mission standards available under section 112(i)(5), it does not contain any reference to sec tion 112(d)(4). Instead, permits under section 112(j) shall contain limitations that the s tate determines to be “equivalent to the limitation that would apply to such source if an em ission standard had been promulgated in a timely manner under subsection (d)....” Here, the difference in treatment between sections 112(i)(5) and 112(d)(4) and EPA’s acknowled gement that its risk-based exemptions are not “emission standards” under secti on 112(d), undercut any argument that state and local permitting authorities have the aut hority to provide such exemptions.

Lastly, EPA’s approach to risk assessment ignores e xisting background concentrations of HAPs and is far too simplistic an approach to provide an “ample margin of safety” as a technical matter. It also fails to co nsider the risk of other HAPs that for which HCl is serving as a surrogate. EPA’s history over the past 40 years in attempting to develop a risk-based approach to regulations of toxic air e missions, and in particular the development of residual risk programs under section 112, demonstrate that these issues are far too complex and significant to be delegated to individual sources as EPA intended.



## Total Selected Metals Alternate Compliance Option

NACAA recommends against inclusion of EPA’s provis ion that would have authorized
sources to limit emissions of Total Selected Metals (TSM) in lieu of limiting PM emissions.
The effect of this alternative was to authorize sou rces with high manganese emissions that employed the risk-based exemption, above, to avoid controlling the other seven metallic HAPs within the TSM group. For many sources, manga nese emissions constitute 80 percent
or more of TSM emissions. Under EPA’s vacated TSM provision, these sources would have been authorized to (1) demonstrate that manganese e missions met the risk-based exemption and (2) assume, thereafter, that manganes e levels were zero in computing compliance with EPA’s TSM limit of 0.0003 lb/MMBtu. Thus, the effect of EPA’s approach would be to effectively multiply the limit for the other seven TSM by a factor of five, without any reference to MACT floor data for those metals o r for PM. EPA offered no technical justification for this approach and we can find non e.

We also believe that TSM emissions data are limite d and not as likely to provide a MACT floor that accurately reflects the best perfor ming sources as PM data. Given the variability of metals content in fuels, the most ef fective MACT is control of fine PM emissions coupled with periodic fuel sampling. Accordingly, NACAA recommends that in most instances TSM limits be discouraged. NACAA strongl y disagrees with that portion of EPA’s vacated rule that would have relied solely on fuel sampling to determine compliance with TSM, but only require fuel sampling once every five years (even where the source of the fuel changed). This latter provision would clearly not be sufficient to ensure continuous compliance.56



## Establishing Limits for Establishing Limits for ICI Boilers

ICI Boilers ICI Boilers

That Burn Mixed Fuels That Burn Mixed Fuels

EPA’s vacated rule contained subcategories for “so lid-fueled” boilers of different sizes, but did not distinguish between types of sol id fuel employed. This simplified the determination of the appropriate limit where a sour ce employs a mixture of fuels, but only to a degree – since there are a number of sources that combust a combination of solid, liquid and gaseous fuels. There appear to be several avai lable approaches. NACAA recommends that, in any event, the source demonstrate the abil ity to comply with the “pure limit” (i.e., the limit that applies when the source is only combusti ng one type of fuel) for each type of fuel it
wishes to combust. Once the source has established the capability of complying using unmixed fuels, then it would appear that the permit ting authority has two options:

1. Assume that the process behaves in a linear fashion and calculate a weighted average emission limit based on the unmixed limits and the percentage of each type of fuel that is being combusted; or

2. Assume that the emissions performance of the system is not necessarily linear (or knowable) and conduct stack tests using the desir ed mix of fuels and the assumed best operation of the control device.

Under either approach, the emission limit when util izing mixed fuels should be lower than
the limit derived for the “dirtiest” fuel.



## Establishing Establishing CO

CO Limits During Turndown Periods Limits During Turndown Periods

The emissions data on which NACAA’s recommended CO MACT floor limits are based typically represent source operations at 80 percent or more of maximum rated load. NACAA recognizes that some well-controlled sources may no t be able meet those limits during transient operations or low-load operation. For un its that normally operate at or near maximum rated load, the exemption for startup and s hutdown operations may suffice to address this issue. Other units may operate for ex tended periods of time at less than 50 percent of rated load. In these circumstances, an additional emission limit should be established, based on the control techniques that w ould need to be employed to meet the MACT floor at rated load. Where the unit normally operates at less than 50 percent rated load, the permitting authority should ensure that t he unit is tuned for best performance at its normal operating load.



## Compiling an Administrative Record

The Permit Guidance includes a reference to a gene ric administrative record on NACAA’s website that, along with site-specific info rmation provided by the source in its Part 2 application, would provide a basis to support the permitting and rulemaking decisions made by the permitting authorities as they are enga ged in the section 112(j) process.57 

# Establishing MACT Limits for New Establishing MACT Limits for New ICI Boilers ICI Boilers ICI Boilers

Section 112(j) requires permitting authorities to develop MACT limits for new 59 sources as well as existing sources. An ICI Boiler heater is “new” if commencement of construction of the unit occurred after January 13, 2003. For the most part the process is similar to that employed in establishing existing s ource MACT requirements. The permitting authority must establish a MACT floor and conduct a MACT analysis. For new sources the
MACT floor is to be set at the emission level achie ved in practice by the best controlled similar source. NACAA has not included specific re commendations for new boiler MACT floors because the result is dependent on the perfo rmance of a single unit. While the NACAA-recommended surrogates, subcategories, emissi on data and variability factors can be used by permitting authorities to develop new so urce MACT floors, NACAA recommends that agencies undertake additional efforts to identi fy the most current information concerning the “best performing similar source” dur ing the permitting of any new ICI Boiler. In addition, the new source MACT analysis is likely to include lower costs for most control options than in retrofit installations.

Section 112(j) also requires a review of permits i ssued under section 112(g) to

determine whether the earlier limits are substantia lly equivalent to the limits that would be required under section 112(j). If those limits are not substantially equivalent, the earlier permit is to be revised to incorporate the more str ingent limits. This may occur because of differences in the applicability of section 112(g) and section 112(j). For new greenfield facilities, sections 112(g) and (j) apply to the sa me units. However, the definition of “construct a major source” under section 112(g) exc ludes new units at an existing source where emissions are routed through a previously ins talled control device or where a proposed control device achieves emission reduction s that are comparable to BACT levels (without consideration of a MACT floor).

59 The requirements for new sources also apply to tho se sources that meet the definition of “reconstruct ed”

sources.58 

# Compliance Demonstrations Compliance Demonstrations

Permitting authorities should consider the use of the reference methods employed in establishing the MACT floor in setting emission lim itations based on the floor. These data are normally the average of three one-hour runs. A ccordingly, where the MACT floor is relied upon in setting the limit, shorter averaging period s should not be used for compliance purposes. Where continuous CO, mercury (“Hg”), PM or parametric monitoring is determined to be the basis of the compliance demons tration, averaging periods should not be less than three hours. However, where the permi tting authority establishes a technology (such as use of a fabric filter) as MACT, any autho rized method (such as an approved alternative to a Federal Reference Method) and its associated averaging period may be employed.

The variability factors identified above are based on the variability associated with repeated reference method tests of an individual un it and are intended for those situations where the permitting authority identifies reference testing, rather than continuous monitoring, as the compliance mechanism. The MACT standards are established to protect against chronic toxic effects. For this reason, av eraging periods of up to 30 days may be appropriate; NACAA recommends rolling 30-day averag es where continuous monitoring is employed. In these situations, the variance associ ated with repetitive testing tends toward zero and so a lesser compliance margin may be appro priate. NACAA believes that it is important, however, not to discourage the use of co ntinuous monitoring by an overly stringent adjustment. Permitting authorities are e ncouraged to balance the competing
interests in this area.

NACAA recommends against incorporating EPA’s langu age that states that “exceedances” of operating parameters established t o ensure compliance with emission limitations are not violations of the permit. Such “exceedances” should be considered violations of the permit, except where they are par t of a CAM or CAM-like plan where the operating parameters are set to correlate with a le vel of performance that is more stringent than the emission limit. Where a permitting author ity establishes parametric monitoring as part of a CAM plan, it should also establish enforc eable parameters that correlate to the
emission limit.59 

# Model Permit Provisions Model Permit Provisions

NACAA recognizes that many permitting authorities have specific formats developed for Title V permitting. Those formats should be em ployed for section 112(j) permits. The following outline is intended to illustrate the iss ues that need to be addressed and suggest language that permitting authorities may find helpf ul.



## Authority

In addition to the permitting authority’s standard boilerplate of authorities, the permit should state that it is being issued pursuant to 42 U.S.C. 7412(j), 40 C.F.R. Part 63, and the delegations of authority found at {cite to the dele gation/approval of the state program by {cite to the delegation/approval of the state progr EPA and any state laws and regulations that transfe r authority to the permit issuer}. r authority to the permit issuer}. The permit should also reference the necessary predicat es (e.g., that the source is a major source pursuant to section 112 and 40 C.F.R. Part 6 3 and any analogous state regulations).



## Definitions

In addition to the permitting authority’s standard reference to state- or locally-defined terms, the permit should state that the words in th is permit have the meaning assigned in
40 C.F.R. 63.2.



## Covered Units

The permit should specifically identify all “indus trial boilers and process heaters” at
the source as “covered units” in the modification o f the Title V permit. Ordinarily, the Title V permit will have set out specific unit identifiers that should be used for this purpose. This description should include existing pollution contr ols and may (in a state with a merged NSR permit program) include a description of the contro ls the source seeks to add.



## Procedural Is Procedural Issues

sues

The permit should reference that a MACT analysis w as performed for each covered unit and that the emission limits selected by the p ermitting authority are no less stringent than the MACT floor determined by the permitting au thority. The permitting authority should also ensure that all public participation requireme nts set out in the General Provisions or required by state law have been met.60



## Emission Limitations

Emission limits may be expressed as is customary i n each state; most states will simply develop a table or series of tables (one for each emission unit):

Unit 527 Unit 527 –

– 250 MMBtu/hr Process Boiler 250 MMBtu/hr Process Boiler 250 MMBtu/hr Process Boiler

P ollutant Emission R ate Measurement M ethod

Particulate M atter (PM) 0 .015 lb/ MMBt u 3-hour block average Method xx 40 CFR XXXX Incorporated as 9 VAC YYYY

Carbon M onoxide 3.5 ppm @ 3% excess O 2, 30

- day rolling average, rolled every 15

minutes CO CEM per 40 CFR XXX

, incorporated as DEQ regulation
9 VAC-XXXX

Hydrogen C hloride 0 .0006 lb/ MMB tu 3-hour block average Method ZZZ, 40 CFR ZZZ incorporated as 9 VAC ZZZ

Mercury 2.5 0 lb/ TB tu 30-day rolling average, rolled every 60 minutes Hg CEM per 40 CFR QQQ, incorporated as 9 VAC QQQ61 

# Glossary of Abbreviations and Acronyms Glossary of Abbreviations and Acronyms

ACI – Activated Carbon Injection
CAA – Clean Air Act
CAAA – Clean Air Act Amendments of 1990 BACT – Best Available Control Technology
CAIR – Clean Air Interstate Rule CAM -- Compliance Assurance Monitoring CAMR – Clean Air Mercury Rule
CEM – Continuous Emissions Monitor CEMS – Continuous Emissions Monitoring System CFR – Code of Federal Regulations CMS – Continuous Monitoring System
CO – Carbon Monoxide COM – Continuous Opacity Monitor ESP – Electrostatic Precipitator FR – Federal Register HAP(s) – Hazardous Air Pollutant(s) HCl – Hydrogen Chloride HF – Hydrogen Fluoride Hg – Mercury ICI Boiler– Industrial, Commercial and Institutiona l Boiler and Process Heater ICR – Information Collection Request IRIS – Integrated Risk Information System
LAER – Lowest Achievable Emission Rate lb/MMBtu – Pounds Per Million British Thermal Units lb/MW/hr – Pounds Per Megawatt-hour lb/TBtu – Pounds Per Trillion British Thermal Units MACT – Maximum Achievable Control Technology Mn – Manganese MW – Megawatt NAAQS – National Ambient Air Quality Standards NACAA – National Association of Clean Air Agencies
NESHAP – National Emission Standards for Hazardous Air Pollutants
NOEL – No Observable Effects Level
NO x – Oxides of Nitrogen
NSR – New Source Review PEMS – Predictive Emissions Monitoring System

PM – Particulate Matter

PM 10 – Particulate Matter of 10 Microns in Diameter or Less

PM 2.5 – Particulate Matter of 2.5 Microns in Diameter or Less ppm – Parts Per Million62

RACT – Reasonably Available Control Technology
SO 2 – Sulfur Dioxide TSM – Total Selected Metals (Arsenic, Beryllium, Ca dmium, Chromium, Lead, Manganese, Nickel, Selenium) WESP – Wet Electrostatic Precipitator

### APPENDIX 1

APPENDIX 1 –

– Example Section 112(j) Part 1 Application Example Section 112(j) Part 1 Application

Michigan Department Of Environmental Quality - Air Quality Division

National Emission Standards for Hazardous Air Pollu tants 40 CFR Part 63 Section 112(j) Affected Sources

Part 1 Notification

Submittal of the completed form to the Michigan Dep artment of Environmental Quality, Air Quality Divis ion (AQD) will fulfill the 40 CFR Part 63 Part 1 application requirement for implementation of Secti on 112(j) of the federal Clean Air Act. Failure to submit information required by Article II, Chapter 1, Part 55 (Air Pollution Control) of P.A. 451 of 1 994, as amended, and the Federal Clean Air Act may result in civil or criminal penalties.

1. Stationary Source Name 2. SRN

3a. ROP No. 3b. ROP Section No. 4. Primary SIC C ode 5. Secondary SIC Code

6a. Address (Street Number and Name)

6b. Address Continued

6c. City 6d. Zip Code 6e. County

7. Location if street address
is not available a. Section b. Township c. Range

8. Contact Name and Title

9. Contact Phone Number 10. Contact E-mail Addre ss

11. This Stationary Source has emission units subj ect to the following MACT Source Category or Catego ries:

G1 Automobile & Light Duty Truck Manufacturing C1 Chlorine Production T1 Asphalt Roofing & Processing

G2 Brick, Structural Clay Prod. & Clay Ceramics Mfg. C2 Flexible Polyurethane Foam Fabrication Operations T2 Coke Ovens: Pushing, Quenching & Battery Stacks

G3 Fabric Printing, Coating & Dyeing C3 Hydrochloric Acid Production/Fumed Silica T3 Combustion Turbines

G4 Friction Products Manufacturing C4 Municipal Solid Waste Landfills T4 Engine Test Cells/Stands

G5 Lime Manufacturing C5 Organic Liquids Distribution (non-gas) T5 Integrated Iron and Steel Manufacturing

G6 Metal Can (Surface Coating) C6 Reinforced Plastic Composites
Production T6 Iron and Steel Foundries

G7 Metal Furniture (Surface Coating) C7 Semiconductor Production T7 Plywood & Composite Wood
Products

G8 Misc. Metal Parts & Products Coating C8 Site Remediation T8 Primary Magnesium Refining

G9 Plastic Parts & Products Coating C9 Haz. Waste Combustors Phase
II: Boilers & HCl Production
Furnaces T10 Industrial, Commercial &
Institutional Boilers & Process Heaters

G10 Refractories Manufacturing C10 Miscellaneous Organic NESHAP (Note: 23 individual source categories are included in this grouping - see instructions for further information) T9 Reciprocating Internal Combustion Engines

G11 Taconite Iron Ore Processing O1 Other

G12 Wood Building Products (surface coating) O2 Other

Note: If requesting a determination of MACT applica bility in accordance with 40 CFR 63.52(d), Item 11 may remain blank. Sufficient information should be provided in Item 12 and/or an AI-001 form for the AQD to make the determination. (See instr uctions.)

Page 1 of 2 EQP5782 (04/02 )64 Michigan Department Of Environmental Quality -Air Q uality Division

12. Identify the types of emission points belongin g to each relevant source category by providing the associated ROP/ MAERS/ PTI Emission Unit ID(s) for the MACT standar d code(s) checked in Item 11.

13. Section 112(g) affected sources -Identify any affected sources for which a Section 112(g) MACT d etermination has previously been made by providing the associated RO P/ MAERS/ PTI Emission Unit ID(s).

14, Additional Information ID – Create an Additional Information (AI) ID that is us ed to provide any supplemental information on Al-001 regarding this submittal.

Al

This form must be signed and dated by a Responsible Official.

___________________________________________________ __________________________________
15. Name and Title of the Responsible Official. Print or type.

___________________________________________________ ________________________________________________ As a Responsible Official, I certify that, based on information and belief formed after reasonable inq uiry, the statements and information in this submittal are tr ue, accurate and complete.

___________________________________________________ __________________________ Signature of Responsible Official Date

Page 2 of 2 EQP5782 (04/02 )65 INSTRUCTIONS FOR COMPLETING THE PART I NOTIFICATION FORM

National Emission Standards for Hazardous Air Pollu tants 40 CFR Part 63

Section 112(j) Affected Sources

“40 CFR 63.53 Application content for case-by-case MACT determinations. (a) Part 1 MACT Application. The Part 1 application for a MACT determination shall contain the information in paragraphs (a)(1) through (4) of thi s section. (1) The name and address (physical location) of th e major source. (2) A brief description of the major source and an identification of the relevant source category. (3) An identification of the types of emission poi nts belonging to the relevant source category. (4) An identification of any affected sources for which a Section 112(g) MACT determination has
been made.”

AQD staff may request submission of additional info rmation and the applicant must respond to such requests in a timely fashion. See 40 CFR 63.52 and 63.53 for further information on the federal requirements for application content, the approval process and time frames for action.

Please print or type clearly when completing this a pplication.

1. Stationary Source Name – Provide the specific name that identifies the Stati onary Source of the application.

2. SRN – Enter the State Registration Number assigned to the Stationary Source.

3a. ROP No. – Enter the Renewable Operating Permit (ROP) Number i f the Stationary Source has been
issued an ROP.

3b. ROP Section No. -Enter the Section Number from the ROP if the Stati onary Source has been
issued an ROP that has more than one Section.

4. Primary SIC Code – Provide the primary Standard Industrial Classificat ion (SIC) Code for this Stationary Source. The primary SIC Code is that whi ch results in the most actual emissions of air contaminants from the Stationary Source. See Append ix D of “RO Permit Application Form Instructions” for a list of SIC Codes.

5. Secondary SIC Code - If applicable, provide the secondary SIC Code for this Stationary Source. The secondary SIC Code is that which results in the second most actual emissions of air contaminants from the Stationary Source. See Append ix D of “RO Permit Application Form Instructions” for a list of SIC Codes.

6a-e. Address – Provide the address for the physical location of th e Stationary Source identified above. A list of County names is available in Appendix C o f “RO Permit Application Form Instructions.”

7. Location - Provide the following information only if a stree t address is unavailable. a. Section: Provide the USGS geographic section cod e. This is a two digit number. b. Township: Provide the USGS geographic township c ode. This is a number followed by N or S. c. Range: Provide the USGS geographic range code. This is a number followed by E or W.

8. Contact Name and Title. – Provide the name and the professional title of the contact person (e.g., Plant Manager, Shift Supervisor, or Consultant).

9. Contact Phone Number. Provide the telephone number and extension, if appl icable, of the contact.66

INSTRUCTIONS FOR COMPLETING THE PART I NOTIFICATION FORM

10. Contact E-mail Address. Provide the e-mail address of the contact.

If the applicant is requesting that the AQD make th e MACT applicability determination, Item 11 may be left blank; however, detailed information must be provid ed in Item 12 and/or on an AI-001 form. (See Item 12 and Item 14 instructions.)

11. This Stationary Source has emission units subject t o the following MACT Source Category or Categories: The source categories listed are those for which a National Emission Standard for Hazardous Air Pollutants (NESHAPS) was not promulgated by the Uni ted States Environmental Protection Agency (U.S. EPA)before an applicable Section 112(j) deadl ine. Information about NESHAPS applicability and the Section 112(j) implementation process may be fo und at the U.S. EPA Air Toxics Website at http://www.epa.gov/ttn/atw. Information about imple mentation of Section 112(j) provisions in Michigan is available at http://www.deq.state.mi.us/aps.

Indicate which Maximum Achievable Control Technolog y (MACT) source category or categories may apply to emission units at this Stationary Source b y checking the associated box. Note that the Miscellaneous Organic (MON) NESHAP covers 23 source categories*. Check the MON NESHAPS box if any of these categories may apply to emissio n units at the Stationary Source.

* Alkyd Resins Production; Ammonium Sulfate Product ion; Benzyltrimethylammonium Chloride Production; C arbonyl Sulfide Production; Chelating Agents Production; Chlorinate d Paraffins Production; Ethyllidene Norbomene Produ ction; Explosives Production; Hydrazine Production; Maleic Anhydride Copolymers Production; Manufacture of Paints, Coati ngs, & Adhesives; OBPA/1, 3-diisocyanate Production; Photographic Che micals Production; Phthalate Plasticizers Productio n; Polyester Resins Production; Polymerized Vinylidene Chloride Product ion; Polymethyl Methacrylate Resins Production; Pol yvinyl Acetate Emulsions Production; Polyvinyl Alcohol Production; Polyvinyl Butyral Production; Quaternary Ammonium Compounds Production; Rubber Chemicals Production; and Symmet rical Tetrachloropyridine Production.

Section 112(d) MACT standards may not be promulgate d by May 15, 2002, for the following additional source categories: PVC & Copolymer Production (Subp art J); Primary Copper Smelting (Subpart QQQ); Petroleum Refineries (Subpart UUU); Paper & O ther Web Coating (Subpart JJJJ); Large Appliance Surface Coating (Subpart NNNN); Metal Coi l Coating (Subpart SSSS); Cellulose Products Manufacturing (Subpart UUUU); and Rubber Tire Manuf acturing (Subpart XXXX). In this event, if emission points at this stationary source may belon g to any of these categories, the “Other” box(es) i n Item 11 must be checked and the name of the source category provided. Refer to U.S. EPA Region 5’s Air Toxics Website http://www.epa.gov/region5/air/t oxics/mact-fr3.htm for current information on the status of MACT standards promulgation.

12. Identify the types of emission points belonging to each relevant source category by providing the associated ROP/ MAERS/ PTI Emission Unit ID(s) for the MACT standard code(s) checked in
Item 11. -In Michigan, emission points are commonly describe d as “emission units” and will be allowed to be identified accordingly. However, the emission points may be described below the emission unit level if necessary to adequately describe the emiss ion point(s).

For each source category checked in Item 11, provid e the Emission Unit ID(s) from the Stationary Source’s current ROP, Permit to Install (PTI) or Mi chigan Air Emission Reporting System (MAERS) report for all emission units that may be subject t o that MACT standard. If more than one source category is checked, associate the Emission Unit ID (s) with the code that is given under the checkbox in Item 11 (e.g., EUBOILER1 & EUBOILER2 = T2; EUREACTO R1 through EUREACTOR9 = C9). Further
information on which emission units are associated with each of the checked categories may be provided with this submittal on an AI-001 form.67

INSTRUCTIONS FOR COMPLETING THE PART I NOTIFICATION FORM

If a determination of MACT applicability by the AQD is being requested for this stationary source, sufficient information must be provided to the AQD to make the determination. The following informati on must be included in Item 12 (or on an AI-001 form i f additional space is needed) for all applicability determination requests:

• a statement that determination of MACT applicabili ty is being requested

• an identification of each point of emission for ea ch hazardous air pollutant or, if a definitive identification is not yet possible, a brief descrip tion of the nature, size, design and method of operation of the source.

13. Section 112(g) Affected Sources -Identify any affec ted sources for which a Section 112(g) MACT determination has previously been made by providing the associated ROP/ MAERS/ PTI Emission Unit ID(s) . If a New Source Review Permit to Install (PTI) wa s previously issued by the AQD that included a Section 112(g) MACT determination, provide the associated Emission Unit ID(s) from the Stationary Source’s current ROP or MAERS report. I f the applicable requirements from the PTI have not yet been incorporated into the ROP, provide the PTI Number and the associated Emission Unit ID(s).

14. Additional Information ID – Create an Additional Information (AI) ID for any ad ditional information or attachments being provided on AI-001. Refer to AI- 001 instructions to create the ID. If the addition al information or attachment is more than one page, la bel each page to show the relationship between

pages.

If a determination of MACT applicability by the AQD is being requested for this stationary source, sufficient information must be provided to the AQD to make the determination. If not provided in Item 12, the following information must be provided on a n AI-001 form for all applicability determination requests:

• a statement that determination of MACT applicabili ty is being requested

• an identification of each point of emission for ea ch hazardous air pollutant or, if a definitive identification is not yet possible, a brief descrip tion of the nature, size, design and method of operation of the source.

15. Responsible Official - This form must be signed by a Responsible Official authorized pursuant to R 336.1118(j) (Rule 118(j)). Print or type the name o f the Responsible Official, followed by the profess ional title of the Responsible Official (e.g., President, Secretary, Treasurer, or Vice President). Provide signature and date where indicated.

The completed Section 112(j) Part 1 Notification an d any attachments must be submitted to the attentio n of the appropriate Air Quality Division District Super visor by May 15, 2002. The submittal must also be copied to U.S. EPA, Compliance and Enforcement - Michigan (AE-17J), 77 West Jackson Boulevard, Chicago, IL
60604.

Instructions Page 3

### APPENDIX 2

APPENDIX 2 –

– Example Section 112(j) Part 2 Application Example Section 112(j) Part 2 Application69

### APPENDIX APPENDIX

3 – NACAA’s Request for ICI Boiler Data NACAA’s Request for ICI Boiler Data

November 15, 2007

Dear NACAA Member:

Section 112 of the Clean Air Act (CAA) requires the U.S. Environmental Protection Agency (EPA) to promulgate a National Emission Standard fo r Hazardous Air Pollutants 60 , often referred to as a “MACT Standard,” for each identified category and s ubcategory of sources of emissions of a lengthy lis t of hazardous air pollutants (HAPs) in accordance wi th schedules developed pursuant to Section 112(e) 61

of the Act.

The U.S. Court of Appeals for the District of Colum bia has “vacated” several MACT standards promulgated by EPA, including the MACT standard for the category designated as “Industrial Boilers and Process Heaters.” This category includes approxima tely 57,000 units that combust coal, natural gas, distillates, residual oils, wood and agricultural m aterials. EPA has determined that the Court’s deci sion to vacate this standard triggers the obligations under section 112(j) of the CAA 62 . Under section 112(j) sources within the category must obtain Title V per mits 63 issued by state permitting authorities on a caseby-case basis incorporating emission limits that th e state determines are “the equivalent emission limitation” that would have applied if EPA had issu ed the MACT standard in a timely manner. Such permits must be issued within 18 months of receipt of a permit application from the source and must be based on “all available information.” In addition, within 60 days of submittal of a Part 2 applicatio n, the permitting authority must notify the source operato r in writing of its determination as to whether the application is complete.

Because of the potentially significant workload res ulting from these activities, the large number of potentially affected sources and the relatively short deadlines for state action imposed by the CAA , the
Board of Directors of the National Association of C lean Air Agencies has invested resources to assist the states in developing MACT permits for the Industria l Boiler and Process Heater category. A technical workgroup, with representatives from approximately 15 state and local air pollution control agencies, has been formed to review available information and pro vide recommendations for plant-by-plant MACT determinations and development of new and existing source MACT floors. A consultant has also been retained to assist the workgroup in gathering relev ant information, collating this information in a us able format and drafting a “model rule” that individual states may draw from as they see fit.

EPA has been and will continue to be involved in th is process. We have met with EPA senior managers and technical staff on several occasions a nd have received excellent cooperation to date. EP A

60 Such standards are required to be based on the app lication of “maximum achievable control technology ” and are colloquially known as “MACT standards.”

61 42 U.S.C. 7412(e)

62 In a pleading filed with the Court of Appeals on M ay 4, 2007, seeking vacatur of the standard, the U. S. Department of Justice asserted on behalf of EPA tha t “EPA recognizes that vacatur of the standards wil l trigger the requirements of Clean Air Act sections 112(g) for n ew sources and 112(j) for existing sources.”

63 Presumably, this includes modifications to existin g Title V permits as well as new Title V permits fo r sources covered by the listed categories.71

staff has been quite helpful in identifying existin g sources of information. It is our intent through out this process to work with EPA to gather information in a manner that avoids duplication of effort and inconsistent data-gathering formats. However, EPA’ s data is quite limited and much of it is more than a decade old. As a consequence, EPA is contemplating a multi-tiered data gathering exercise as part of its future rulemaking efforts. This information may no t be available to the states in a timeframe consist ent with section 112(j) requirements.

For this reason we are asking each of the states to provide NACAA with information we believe is needed for the states to draft permits a s required by section 112(j ). We will collate this
information and make it available to each state so that it can satisfy section 112(j)’s obligation tha t MACT determinations be made on the basis of “all av ailable information.” As a general matter, this
information includes for all industrial boilers and process heaters:

(1) controlled and uncontrolled CO, PM and SO 2 emission data; (2) any HAP emission data; (3) any data correlating HAP emission control with cont rol of criteria pollutants; (4) cost and performance data – especially for good con trols on small- and medium-size boilers and process heaters; and (5) fuel sampling data for coal, wood and liquid fuels.

We are providing electronically with this letter EP A’s spreadsheet that identifies those units that EPA believed, in 1998, to be in the category subjec t to these requirements. We believe this database contains a number of errors and ask that you review it to assist in determining the affected universe so that NACAA and states can accurately calculate MACT floors. We also are providing electronically Excel spreadsheet formats and more specific informa tion about the data requested that, in the interest s of providing consistent and comparable information to the states, we ask you to use in responding to this request. We ask that you provide this information electronically to Mary Sullivan Douglas of NACAA at mdouglas@4cleanair.org by December 18, 2007.

We will hold a conference call on November 27, 2007 from 3:00 to 4:00 p.m. (Eastern time) to answer general questions about this request . The call-in number is (866) 365-4406 (passcode 6 055799#). If more than one person from your agency will parti cipate, we ask that they try to do so from the same telephone, to minimize the number of lines needed. Also, please feel free to call Mary Sullivan Dougl as at 202-624-7864, Bruce Buckheit at 703-280-1383 or any member of the NACAA technical review committee (list provided electronically) if you hav e any suggestions at to how best to expedite this process or if you have any specific questions not l ikely to be addressed on the conference call.

I understand that this data request will require th at you divert scarce resources from other priorities. However, I am convinced that this proc ess will prove to be the most efficient way to reac h the environmentally responsible decisions that I know y ou strive for.

Our plan for the model rule is to develop a draft t his winter, followed by a review period. We hope to complete the document by early spring 2008. We thank you for your assistance with this effort

.

Sincerely,

S. William Becker72 ADDITIONAL INFORMATION RESPECTING NACAA BOILER MACT INFORMATION REQUEST

The NACAA information request generally seeks: (1) controlled and uncontrolled CO, PM, and SO2 emission data; (2) any HAP emission dat a; (3) any data correlating HAP emission control with control of criteria pollutants; (4) co st and performance data for HAP emission reduction measures, especially for small and medium size boilers and process heaters and (5) fuel sampling data for coal, wood and liquid fuels. This memorandum is intended to provide additional information concerning the request and t o answer several questions that have been anticipated.

The data sought by NACAA is limited to existing da ta and is not intended to lead to additional testing of sources. State and local aut horities are; of course, free to require additional testing as they see fit. For HAP emission data, we ask that you simply forward the information electronically in whatever format is most convenien t for you. The most useful HAP information is testing that enables us to determine whether a c orrelation exists between HAPs of concern and criteria pollutants. Initial work suggests that su ch a correlation may exist between CO emissions and organic HAPs, SO 2 emissions and acid gas HAP emissions and PM emissio ns and metal HAP emissions. If the state or local authority has not formatted its HAP data electronically, we suggest the format set out below. It is likely th at there is substantially more data concerning criteria pollutants emitted by this category and so we request, where practicable, that state and local authorities use the attached spreadsheet.

Initial work also suggests the following subcatego ries based on type of fuel: (1) coal (all types, including waste coal); wood (including woody materials and other solid organic renewable fuels, such as bagasse); oil (all types) and gaseou s fuels (all types). Where a source is actually fueled by multiple types of fuel on a regular basis , please so indicate and advise which type of fuel (including, where applicable a combination of types) the emissions data and limits represent. If one type of fuel is predominantly combusted by d ual fuel capacity units, please classify that source in the appropriate subcategory.

You may also submit data concerning “similar” sourc es, even though they are not in the industrial and commercial boiler and process heater category, since emissions from such sources may be relevant to development of the Model Rule. If you do so, we ask that you provide a note in the “comments” section. EPA’s source category l isting for this category included direct-fired process heaters, but the vacated rule did not. Sin ce we cannot now determine what path EPA will ultimately adopt, we are seeking information for the entire listed category, including directfired process heaters. Please identify any such so urces in the comment section and include a notation for any such heaters that are subject to r egulation under other MACT rules. Similarly,
an undetermined number of units that combust waste materials may ultimately be subject to regulation under section 129 of the CAA rather than under section 112. EPA has wrestled with this issue for a number of years and it may be seve ral more years before this issue is finally resolved. In addition to uncertainty as to the siz e and makeup of facilities subject to section 129, no determination has yet been made as to whether st ates are required to conduct case-by-case 112(j) MACT determinations until such time as EPA r evises its definition of waste and promulgates a regulation under section 129. Pendin g resolution of these issues, we believe it is appropriate to at least gather information that wil l allow us to determine whether inclusion of73

potential section 129 sources in the MACT floor dat a base will materially alter the determination of the MACT floors for different subcategories of u nits that do not burn waste.

State and local authorities may have emissions dat a on a particular unit that represents numerous tests over a substantial number of years. In such instances, please submit only the most recent three test results that you believe are representative of source operation under the tested conditions. Where test results vary because of known reasons, or you believe a test result is an outlier that does not accurately reflect plan t emissions, please provide a comment in the “comment” field. In order to provide for compariso n of common data, we have asked that all emissions date be provided in a “lb/mmbtu” format. Please let us know if this request poses a large resource problem or is inappropriate for a pa rticular pollutant.

NACAA is also seeking performance and cost informa tion on good performing HAP reduction options, especially for small and medium sized sources within the category. These options may include new and emerging technologies f or pollution prevention or material substitutions as well as combustion or post combust ion controls. We ask that you provide any information you may have on available options, in w hatever form you have, including any MACT, RACT, BACT or LAER decisions that may not hav e been entered in the RBLC. In addition, if your jurisdiction has imposed emission limits on any the above-listed pollutants that you believe might be relevant to consideration of f acility-specific MACT determinations or the development of MACT floors; please provide informat ion concerning the limits, the affected population and any information you may have about c ompliance with such limits.

We would also appreciate any information you would care to provide that is relevant to any of the issues that must be resolved in developi ng a Model Rule that is useful to NACAA’s
members. These issues include identification of “a chievable” control measures, developing factors for consideration of cost and other issues, developing enforceable limits on the basis of the available data as well as “enhanced” monitoring and reporting requirements. Finally, we welcome any questions or comments that you may have concerning this project and the “MACT hammer” process under section 112 of the Clean Air Act.74 DESCRIPTION OF FIELDS IN BOILER MACT TABLE

FIELD DESCRIPTION

Facility Name The name of the facility where the em issions source is located.

E.g., Becker Oil and Refining Company.

Location The geographic location of the facility-- city and state.

Unit ID The identification number assigned by the f acility to the emissions source (unit).

Process Description Any additional information provided in the report t hat describes

the unit’s design or use.

Capacity The operating capacity of the emissions un it expressed in

mmbtu/hr.

Pollutant Identify the specific pollutant.

Emissions Emissions of the designated pollutant in lb/mmbtu. Please be

sure to include all available data concerning mercu ry compounds, acid gas (SO 2, HCl and HF), CO, NO 64

x , PM and

PM 10 emissions.

Emission limit Applicable limit(s) for the specifie d pollutant converted to

lb/mmbtu, please identify the averaging period for the limit.

Uncontrolled
emissions Uncontrolled emissions of the designated pollutant in lb/mmbtu.

Unit Type Code assigned to each type of emissions source. “B ” indicates

industrial boiler, “C” indicates commercial boiler, “D” indicates direct fired process heater, “I” indicates indirect fired process heater and “S” indicates that the source is likely a solid waste
incinerator.

Comments Any comments or supplemental information. Include in this

column a notation (“C”) where the testing was compl iance testing that was intended to replicate reasonable w orst case conditions for the source

64 We have not identified a potential correlation bet ween a HAP of concern in this sector and NO

x emissions. We have included this pollutant so as to be able devel op a comprehensive data set that minimizes the poss ibility of a second information request for MACT development pur poses and that provides useful information to state and local air program administrators involved in PM 2.5 and ozone reduction activities.75

Fuel Information Information provided regarding the type or composit ion of the

fuel, including mercury, metals and sulfur content and moisture content (especially for wood waste).

Control Equipment Description of the control device in use during tes ting and/or

used to comply with the applicable emission limits.

Additional Capacity
Information Any additional information regarding the design cap acity of the

unit.

MACT Status Using the following codes, indicate whether a MACT Part 1

(“M1”) or Part 2 (“M2”) application has been receiv ed and whether the emissions unit was certified as in comp liance with the now vacated Boiler MACT standard (“MC”). Also indicate whether the emissions unit has been the subject of a MACT determination under section 112(g) (“112(g)”), 112( j) (“112(j)”) or a BACT (“BACT”) or LAER (“LAER”) determination.

Contact Contact information (name, telephone number and e-m ail

address) of the agency person designated to receive and response to queries concerning the data submission.76 NACAA Boiler MACT Spreadsheet (original version in Excel)

Page 1

Facility Name Location Unit ID Process Description

Page 2

Capacity Pollutant Emissions Emission
Limit Uncontrolled

emissions Unit type (mmbtu/hr) (lb/mmbtu) (lb/mmbtu) (lb/mmbtu)

Page 3

Comments Fuel Information Control Equipment

Page 4

Additional control
information Additional capacity
information Data
Date MACT Status

Page 5

Contact77



### A A PPENDIX 4 PPENDIX 4 PPENDIX 4

– Summary of Health Effects of Hazardous Air Polluta ts Emitted Summary of Health Effects of Hazardous Air Pollutan ts Emitted

by ICI Boilers

Chronic exposure to acetaldehyde is known to cause adverse effects on the nasal epithelium and mucous membranes as well as increase d kidney weight. Acetaldehyde is also classified as a Group B2, probable human carci nogen.

Long-term arsenic inhalation is associated with i rritation of the skin and mucous
membranes and an increased risk in women of adverse reproductive effects. Inhalation of inorganic arsenic is strongly associated with lung cancer as well as skin and bladder cancer. Arsenic is classified as a Group A, known human carc inogen.

Chronic benzene inhalation is known to be associate d with blood disorders including
reduced red blood cell counts and leukemia. EPA has classified benzene as a Group A, known human carcinogen.

The chronic effects of inhalation exposure to bery llium are focused in the lungs, where beryllium is associated with the formation of noncancerous lesions (berylliosis) and an increased risk of lung cancer. Beryllium is clas sified as a Group B1, probable human carcinogen.

Chronic cadmium exposure is known to cause kidney d isease and may be associated with fetal defects at high doses. EPA has classifi ed cadmium as a Group B1, probable human carcinogen based on animal studies that show an increase in lung cancer from longterm inhalation exposure to cadmium.

Chlorine is an irritant to the eyes, the upper res piratory tract and the lungs. Chronic exposure to chlorine has led to respiratory effects , such as eye and throat irritation and
airflow reduction. EPA has not classified chlorine for potential carcinogenicity.

Hexavalent chromium is a particularly hazardous ai r pollutant and, like beryllium, affects the respiratory tract, causing bronchitis, pneumonia and other respiratory effects at high, chronic doses. At lower chronic doses hexava lent chromium has been associated with complications during pregnancy and childbirth, nasa l and sinus irritation and damage, skin irritation and ulceration and eye irritation and da mage. Hexavalent chromium is also associated with lung, kidney and liver damage and wi th lung cancer (when inhaled). Hexavalent chromium is classified as a Group A, know n human carcinogen. Trivalent chromium is substantially less toxic than hexavalen t chromium and is an essential element in humans (i.e., there is a recommended minimum int ake for trivalent chromium). Trivalent
chromium has been identified as a sensitizer that l eads to skin sensitivity and allergic response as well as asthmatic responses, but is not classified as a carcinogen.

Formaldehyde is an irritant of the eyes, nose and throat. Exposure to formaldehyde is also associated with adverse reproductive effect s as well as lung and nasopharyngeal cancer. EPA has classified formaldehyde as a Group B2, probable human carcinogen.

Chronic exposure to ethyl benzene by inhalation in humans has shown conflicting results regarding its effects on the blood. Animal studies have reported effects on the blood, liver, and kidneys from chronic inhalation exposure to ethyl benzene. Limited information is78

available on the carcinogenic effects of ethyl benz ene in humans. In a study by the National Toxicology Program (NTP), exposure to ethyl benzene by inhalation resulted in an increased incidence of kidney and testicular tumors in rats, a nd lung and liver tumors in mice. EPA has classified ethyl benzene as a Group D substance , not classifiable as to human carcinogenicity.

Human chronic exposure to hexane in air is associa ted with polyneuropathy – a neurological disorder that occurs when many periphe ral nerves throughout the body malfunction simultaneously. Symptoms include numbn ess in the extremities, muscular weakness, blurred vision, headache and fatigue. Neu rotoxic effects have also been
exhibited in rats. No information is available on the carcinogenic effects of hexane in
humans or animals. EPA has classified hexane as a Group D substance, not classifiable as to human carcinogenicity.

Long-term exposure of humans to fluoride at low l evels has a beneficial effect of dental cavity prevention and may also be useful for the treatment of osteoporosis. Chronic inhalation exposure of humans to hydrogen fluoride has resulted in irritation and congestion of the nose, throat and bronchi at low levels. Incr eased bone density has been reported among workers chronically exposed to fluorides (incl uding hydrogen fluoride) via inhalation. Damage to the liver, kidneys and lungs has been obse rved in animals chronically exposed to hydrogen fluoride by inhalation. EPA has not class ified hydrogen fluoride for carcinogenicity.

Manganese is essential for normal physiologic func tioning in humans and animals, and exposure to low levels of manganese in the diet is considered to be nutritionally essential in humans. Chronic exposure to high leve ls of manganese by inhalation in humans may result in central nervous system effects. Visu al reaction time, hand steadiness and eyehand coordination were affected in chronically expo sed workers. Respiratory effects have also been noted in workers chronically exposed by in halation. No studies are available regarding carcinogenic effects in humans or animals from inhalation exposure to manganese. No studies are available regarding canc er in humans from oral exposure to manganese. Oral animal studies on manganese sulfat e are reported to be inadequate, with several studies reporting negative results, one stu dy reporting an increased incidence of thyroid gland follicular cell adenomas and hyperpla sia, and one study noting an increased incidence of pancreatic tumors. EPA has classified manganese as a Group D substance, not classifiable as to carcinogenicity in humans.

Chronic effects of mercury differ, depending on the form of the mercury. The central nervous system is impaired by chronic exposure to e lemental mercury. Effects noted include increased excitability, irritability, exces sive shyness, insomnia, severe salivation, gingivitis and tremors. Additional chronic impacts of elemental mercury exposure include adverse kidney effects and, in some children, acrody nia, a rare syndrome characterized by severe leg cramps, irritability, paresthesia (a sen sation of prickling on the skin) and painful pink fingers and peeling hands, feet and nose. The p rimary effect from chronic exposure to inorganic mercury is kidney damage, primarily due to mercury-induced autoimmune glomerulonephritis (induction of an immune response to the body's kidney tissue) in humans. Acrodynia may also occur from exposure to inorganic mercury compounds. The primary effect from chronic exposure to methyl merc ury in humans is damage to the central nervous system. The earliest effects are symptoms such as paresthesia, blurred vision and malaise. Effects at higher doses include deafness, speech difficulties, and constriction of the visual field. Studies on the reproductive and developmental effects of elemental79

mercury in humans have shown mixed results. One st udy did not see an association between mercury exposure and miscarriages, while an other revealed an increase in the rate of spontaneous abortions. A third study showed a h igher-than-expected frequency of birth defects, which was not confirmed in a fourth study. No information is available on the reproductive or developmental effects of inorganic mercury in humans. Animal studies have reported effects including alterations in testicula r tissue, increased resorption rates and abnormalities of development.

Several studies have been carried out regarding e lemental mercury and cancer in
humans. These studies are inconclusive due to lack o f valid exposure data and confounding factors. EPA has classified elemental mercury as a Group D substance, not classifiable as to human carcinogenicity, based on inadequate human an d animal data. No studies are available on the carcinogenic effects of inorganic mercury in humans. A chronic study on mercuric chloride in rats and mice reported an incr eased incidence of forestomach and thyroid tumors in rats, and an increased incidence of renal tumors in mice. EPA has classified an inorganic mercury compound, mercuric chloride, as a Group C, possible human carcinogen, based on the absence of data in humans and limited evidence of carcinogenicity in rats and mice. No studies are a vailable on the carcinogenic effects of methyl mercury in humans, and the one available ani mal study reported renal tumors in mice. EPA has classified methyl mercury as a Group C, possible human carcinogen, based on inadequate data in humans and limited evidence o f carcinogenicity in animals.

Dermatitis is the most common effect in humans fro m chronic dermal exposure to nickel. Cases of nickel dermatitis have been report ed following occupational and nonoccupational exposure, with symptoms of eczema (ras h, itching) of the fingers, hands, wrists and forearms. Chronic inhalation exposure to nickel in humans also results in adverse respiratory effects, including a type of asthma spe cific to nickel, decreased lung function and bronchitis. Animal studies have reported adver se effects on the lungs and immune system from inhalation exposure to soluble and inso luble nickel compounds (nickel oxide, subsulfide, sulfate heptahydrate). However, nickel sulfate has been determined to be not carcinogenic in either rats or mice via inhalation. EPA has not evaluated soluble salts of nickel as a class of compounds for potential human c arcinogenicity. Human studies have reported an increased risk of lung and nasal cancers among nickel refinery workers exposed to nickel refinery dust. Nickel refinery dust is a m ixture of many nickel compounds, with nickel subsulfide being the major constituent. Anim al studies have also reported lung tumors from inhalation exposure to nickel refinery d usts and to nickel subsulfide. EPA has classified nickel refinery dust and nickel subsulfide as Group A, human carcinogens.

Most phosphorus is used in the production of phosp horic acid and phosphates, which are used in the fertilizers industry. White phosphorus is used in the manufacture of munitions, pyrotechnics, explosives, smoke bombs, ar tificial fertilizers, rodenticides, phosphor bronze alloy, semiconductors, electrolumin escent coatings and chemicals. Chronic exposure to white phosphorus in humans resu lts in necrosis of the jaw. Progressive symptoms begin as a local inflammation or irritatio n and proceed to swelling, ulceration, and destruction of the jawbone with perforation to the sinus or nasal cavities and externally to the cheek. In one occupational study, anemia and le ukopenia were observed. Animal studies have reported effects on the blood from inh alation exposure to white phosphorus. No information is available on the carcinogenic eff ects of white phosphorus in humans or animals. EPA has classified white phosphorus as a Group D substance, not classifiable as to human carcinogenicity.80

The term polycyclic organic matter (POM) defines a broad class of compounds that includes the polycyclic aromatic hydrocarbon compou nds (PAHs), of which benzo[a]pyrene is a member. POM compounds are formed primarily from combustion and are present in the atmosphere in particulate form. Sources of air emi ssions are diverse and include cigarette smoke, vehicle exhaust, home heating, laying tar and grilling meat. Cancer is the major concern from exposure to POM. Epidemiologic studie s have reported an increase in lung cancer in humans exposed to coke oven emissions, roo fing tar emissions and cigarette smoke; all of these mixtures contain POM compounds. Animal studies have reported respiratory tract tumors from inhalation exposure t o benzo[a]pyrene and forestomach tumors, leukemia and lung tumors from oral exposure to benzo[a]pyrene. EPA has classified seven PAHs, as Group B2, probable human carcinogens

.

Skin exposures to mixtures of carcinogenic PAHs cau se skin disorders in humans and animals, and adverse skin effects have been noted in humans and animals following application of solutions containing benzo[a]pyrene. An epidemiological study of workers exposed by inhalation to benzo[a]pyrene and other p articulate matter reported some respiratory effects. The role of benzo[a]pyrene in this association, however, is reported to be unclear. Animal studies have reported effects on t he blood and liver from oral exposure to benzo[a]pyrene and a slight hypersensitivity respon se from dermal exposure to benzo[a]pyrene.

Selenium is a naturally occurring substance that i s toxic at high concentrations, but is
also an essential element in the human diet. No i nformation is available on the chronic effects of selenium in humans from inhalation expos ure. In epidemiological studies of populations exposed to high levels of selenium in f ood and water, discoloration of the skin, pathological deformation and loss of nails, loss of hair, excessive tooth decay and discoloration, garlic odor in breath and urine, lac k of mental alertness and listlessness were reported. "Alkali disease" is a disease in livestoc k resulting from chronic consumption of high levels of selenium; it is characterized by hai r loss, deformation and sloughing of the hooves, erosion of the joints of the bones, anemia and effects on the heart, kidney and liver. The consumption of high levels of selenium in the d iet by pigs, sheep and cattle has been shown to interfere with normal fetal development an d to produce fetal malformations. Epidemiological studies that used the selenium conc entration in crops as an indicator of dietary selenium have generally reported an inverse association between selenium levels and cancer occurrence. Animal studies have reporte d that selenium supplementation, as sodium selenate, sodium selenite and organic forms of selenium, results in a reduced incidence of several tumor types. Selenium sulfide has been shown to be carcinogenic in animals (an increase in liver tumors in rats and mi ce and lung tumors in female mice from oral exposure). However, selenium sulfide is a pha rmaceutical compound used in antidandruff shampoos and is unrelated to the inorganic or organic selenium compounds found
in foods and the environment. EPA has classified e lemental selenium as a Group D substance, not classifiable as to human carcinogeni city, and selenium sulfide as a Group B2, probable human carcinogen.

Chronic exposure of humans to mixed xylenes, as se en in occupational settings, has resulted primarily in neurological effects such as headache, dizziness, fatigue, tremors, incoordination, anxiety, impaired short-term memory and inability to concentrate. Labored breathing, impaired pulmonary function, increased h eart palpitation, severe chest pain, abnormal EKG and possible effects on the kidneys hav e also been reported. Mixed xylenes81

have been shown to produce developmental effects, s uch as an increased incidence of skeletal variations in fetuses, delayed ossification , fetal resorptions and decreased fetal body weight in animals via inhalation exposure. So me studies observed maternal toxicity as
well.

Mixed xylenes have not been extensively tested for chronic effects, although animal
studies show effects on the liver and central nervo us system from inhalation and oral exposures and effects on the kidneys from oral expos ure to mixed xylenes. No information is available on the carcinogenic effects of mixed x ylenes in humans. An increase in tumors was not reported in rats or mice exposed to mixed x ylenes via gavage (experimentally placing the chemical in the stomach). Other animal studies have reported equivocal results. EPA has classified mixed xylenes as a Group D subst ance, not classifiable as to human carcinogenicity.