Moving Towards Multi-Air Pollutant 

Reduction Strategies in Major U.S. 

Industry Sectors

A Report to the 

U.S. Environmental Protection Agency’s 

Clean Air Act Advisory Committee (CAAAC)

Revised Draft – June 1, 2011

Do Not Cite or Quote.
Sector-based Multi-pollutant Strategies i

Moving Towards Multi-Air Pollutant 

Reduction Strategies in Major U.S. 

Industry Sectors

Executive Summary

A Report to the U.S. Environmental Protection Agency’s 

Clean Air Act Advisory Committee

[Placeholder]
Sector-based Multi-pollutant Strategies 

 1

Moving Towards Multi-Air Pollutant 

Reduction Strategies in Major U.S. 

Industry Sectors

A Report to the U.S. Environmental Protection Agency’s 

Clean Air Act Advisory Committee

Revised Draft — June 1, 2011

I. Introduction

Since the passage by Congress of the Clean Air Act Amendments of 1990, the U.S. 

Environmental Protection Agency (EPA) and the U.S. business community have invested 

significant resources in creating a world-class system of clean air protection. The results 

of these investments have been nothing less than impressive. The air is cleaner and 

public health has improved dramatically.1 

Driving this improvement in air pollution in the U.S. has been a comprehensive system 

of environmental regulation developed at the federal level and implemented through 

state, tribal, and local action. The improvements to air quality in the U.S. have been the 

result of investments in new technology and new environmental management 

processes in every sector of the U.S. economy. Developing and complying with the 

requirements of the Clean Air Act is a complex undertaking for both the regulators and 

the regulated community alike.

The Clean Air Act outlines numerous programs of air pollution control that require 

numerous regulations. Title by title, the Act requires national investments to reduce the 

health effects associated with criteria and air toxic emissions and improve the health of 

our environment by reducing acid rain, smog, and stratospheric ozone depletion. Every 

industrial sector of the U.S. economy is affected to some degree by these regulatory 

requirements. Most industrial sectors are subject to numerous Clean Air Act regulations 

simultaneously. For example, the chemical manufacturing industry is currently subject

to 14 air toxics (MACT) standards and 6 criteria air pollutant (NSPS) standards among 

others. Some of these regulations reflect updates to existing requirements and others 

affect new sources and employ new methods of control. A single industrial process can 

be subject to different regulations controlling different forms of air pollution and each 

 

1

 See “The Benefits and Costs of the Clean Air Act of 1990 to 2020,” U.S. Environmental Protection Agency, 

Office of Air and Radiation, March 2011 Summary Report for a full discussion of the costs and benefits of 

the Clean Air Act. 
Sector-based Multi-pollutant Strategies 

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of these rules is unique in some way. In some cases, separate rules may regulate the 

same emission point in a facility using different definitions, emission limits and separate 

recordkeeping and reporting requirements. In addition, these regulations must be 

updated on a periodic basis to reflect improvements in air pollution control technology 

and resultant improvements to the air we breathe. For example, the Clean Air Act 

requires an update of the technology aspects of the air toxics (MACT) rules every 8 

years. Likewise, the new source performance standards (NSPS) rules controlling criteria 

pollutants for industry must also have a review of technology every 8 years.

In this complex era of air pollution control, optimizing our nation’s clean air investments 

requires a simultaneous consideration of all of our air quality goals. Reductions in 

criteria air pollution emissions such as fine particulate matter must be considered sideby-side with reductions in air toxics emissions such as benzene. Clean air investments 

must also be implemented in a manner that enhances and supports energy efficiency.

To meet this challenge, EPA is investing resources in developing approaches that 

consider more than one type of air pollution at a time. These “multi-pollutant” 

approaches have been recognized as a key approach for the next generation of clean air 

strategies. EPA is pursuing these approaches in many priority sectors of the U.S. 

industrial economy. The potential benefits of these multi-pollutant sector-based 

approaches are accompanied by significant challenges. This report presents a discussion 

of these benefits and challenges, a Framework for evaluating new approaches, and a set 

of recommendations for moving forward.

II. Work Group Approach

To identify the challenges and opportunities that a multi-pollutant, sector-based 

approach offers, EPA’s Clean Air Act Advisory Committee (CAAAC) held an initial 

discussion in May 2010, formed a Multi-Pollutant Sector-Based Work Group (“Work 

Group”) to provide advice on the regulatory and technological strategies to consider,

and then convened the Work Group in October 2010 to further investigate this type of

approach. 

Early Work Group Discussions

At its May, 2010 meeting, the CAAAC’s Subcommittee on Economic Incentives and 

Regulatory Innovation discussed EPA’s initial developments of sector-based approaches 

to air pollution control. Matthew Witosky of OAQPS’s Sector Policies and Programs 

Division (SPPD) addressed efforts to coordinate the development of air toxics (MACT) 

and new source performance standards (NSPS) in industrial sectors.

2

 Brenda Shine

then presented the multi-pollutant sector-based work of their SPPD for the petroleum 

 

2

EPA. “Sector-Based Multipollutant Approaches for Stationary Sources,” presented to CAAAC 

Subcommittee Meeting, May 26, 2010.
Sector-based Multi-pollutant Strategies 

 3

refinery sector.3 Based on interest resulting from these discussions, the CAAAC formed 

a multi-stakeholder Work Group with the purpose of providing the CAAAC with 

information, advice, and recommendations regarding the development and 

implementation of an air pollution stationary source multi-pollutant approach (see 

Appendix A for the Work Group charter and members).

The Work Group identified a number of questions worthy of exploring and a number of 

methods to assess these. Some of the questions highlighted for followup included:

How should stationary source air pollution regulation be better coordinated and 

what are the benefits and challenges of increased coordination?

What are the regulatory and legal challenges to implementing sector-based, 

multi-pollutant approaches?

How should the coordination of regulatory timelines and requirements begin 

within a sector? 

Which advanced technologies will assist in controlling multiple types of air 

pollution?

What are the co-benefit, energy, and research implications of these 

technologies?

What are the market-based mechanisms that EPA should be investigating for 

sector-based approaches that would help the sector to be more efficient?

How can EPA better incentivize facilities to replace outdated or poorly 

performing equipment and improve energy efficiency while reducing 

malfunctions? How does a sector-based or multi-pollutant approach help?

Are there financing and investment programs that can be utilized to help 

implement sector-based approaches and specific technologies?

In addition to these general issues, the Work Group considered a number of strategies 

that could facilitate the adaptation of multi-pollutant, sector-based approaches. During 

the October 2010 meeting, Work Group member Patrick Traylor presented a paper for 

discussion that highlighted a number of potential needs associated with implementing

source-wide multi-pollutant strategies4:

Explore the challenges of reforming air pollution source category definitions 

from unit-by-unit to facility-wide definitions.

Explore the challenges of developing emission standards for air toxics (National 

Emission Standards for Hazardous Air Pollutants – NESHAPs) and criteria air 

 

3

EPA. “Petroleum Refinery Sector Update,” presented to CAAAC Subcommittee Meeting, May 26, 2010. 

4

Patrick Traylor. A Conceptual Framework for a Source-wide Multi-pollutant Strategy. White paper 

prepared for the Economic Incentives and Regulatory Innovation Subcommittee of the Clean Air Act 

Advisory Committee, August 2010.
Sector-based Multi-pollutant Strategies 

 4

pollutant programs (NSPS, New Source Review - NSR) based on a common set of 

regulated air pollutants.

Explore the challenges of coordinating the periodic revision of the National 

Ambient Air Quality Standards (NAAQS) with the required updates of NESHAPs

and NSPS standards.

Explore the challenges of utilizing work practice standards in situations where 

quantifiable emission limitations and reductions are needed, such as the new 

source review program requirements.

Explore the challenges of utilizing plant-wide applicability limits (PALS) or other 

forms of averaging emission reductions within a facility’s fence line.

Sector-Based Roundtable Discussions

To further investigate the opportunities and challenges of moving towards a multipollutant system of air pollution regulation at stationary sources, the Work Group 

conducted sector-based roundtable discussions with the iron and steel industry on 

March 3, 2011 and with the chemical manufacturing industry on March 31, 2011.

5

 

Each roundtable discussion included presentations from industry trade associations and 

representatives from individual companies, and utilized a framework of topics to guide 

the discussion. Company presentations addressed advanced technology plans and 

possibilities; air pollution co-benefit assessments for their facilities; multi-pollutant 

regulatory strategies; and environment and economic opportunities. Each discussion 

highlighted the environmental, economic, and legal-regulatory implications of a sectorbased approach for the companies. The results of these roundtable discussions are 

included in the Observations Section of this report.

 

5

Iron and Steel roundtable industry participants included the American Iron and Steel Institute, U.S. Steel, 

Arcelor Mittal, and Nucor. Chemical manufacturing roundtable industry participants included the American 

Chemistry Council, 3M and Flint Hills Resources.
Sector-based Multi-pollutant Strategies 

 5

III. Background

Current air pollution control policies and practices have resulted in significant emissions 

reductions of air pollutants and their concentration in the atmosphere. To obtain these 

reductions, EPA has developed a comprehensive system of regulations and guidance to 

implement the requirements of the Clean Air Act (CAA) Sections 111 (new source 

performance standards), 112 (air toxics), 129 (solid waste combustion) and others. 

Industrial sources now face the task of developing and installing equally comprehensive 

air pollution control and compliance systems. Future progress depends on increased 

coordination between these clean air programs. This necessity was recognized by the 

National Academy of Sciences’ 2004 report recommending that EPA take an integrated, 

multi-pollutant approach to air quality management.6 

An Overview of EPA’s Multi-pollutant, Sector-Based Approach

Over the past decade, EPA has transitioned to a more integrated multi-pollutant 

approach called the “multi-pollutant sector-based approach.” By using a more holistic 

approach, EPA hopes to achieve better environmental benefits in a more efficient 

manner. To maximize potential environmental benefits, this new regulatory framework 

challenges EPA to develop strategies, policies, and regulations that consider the impacts 

of all air pollutants emitted from the source(s) or industrial sector in a coordinated 

manner. Specifically, by implementing this approach, EPA expects to achieve the 

following results:

Maximize the co-benefits from air pollution control investments.

Expand integration of multi-pollutant reduction strategies, such as energy 

efficiency and pollution prevention considerations into air pollution control 

investments and management.

Promote additional source-wide emission reductions beyond minimum 

statutory requirements.

Accelerate the development and use of innovative emission reduction 

technologies, measures, and strategies.

This transition has both recognized and driven improvements in multi-pollutant 

emission inventories, human and environmental health risk science, and air pollution 

control technology. 

 

6

Committee on Air Quality Management in the United States, National Research Council. Air Quality 

Management in the United States, National Academies Press, Washington, DC. 2004.
Sector-based Multi-pollutant Strategies 

 6

EPA’s new analytic capacity includes developments in integrated emissions inventories, 

integrated air modeling and monitoring capacity, and advancements in multipollutant 

technology and cost assessment tools.7

For example, the Industrial Sectors Integrated Solutions Model (ISIS) was developed in 

2008 and has been useful in developing integrated approaches. This dynamic model is 

designed to provide information on the optimal industry operation and emission 

reduction requirements, the suite of cost-effective controls needed to meet certain 

emission limits, engineering cost of controls, and the economic response of the industry 

to a proposed policy. EPA has also been developing new software tools to help estimate 

the multiple emission reductions available from various emission reduction 

technologies. For example, the Control Strategy Tool (CoST) allows users to generate 

multipollutant emission inventories and reduction projections together with information 

about the cost of the technologies applied.8 CoST facilitates a level of collaboration 

between control strategy development and emission inventory modeling that was not 

previously possible.

Utilizing this new analytic capacity, EPA’s Office of Air Quality Planning and Standards 

(OAQPS), has worked with stakeholders to understand and establish priorities and 

develop regulatory strategies for industrial sectors. This grouping of rule-making 

activities by industrial sector resulted in a total of 70 sector groupings, 55 of which are 

covered by stationary source regulations. Using a number of factors (hazardous and 

criteria emissions, cancer and non-cancer toxicity of emissions, non-attainment area 

emissions and GHG emissions), EPA developed several different ranking exercises of 

these sectors. In general, ten to fifteen industrial sectors consistently showed up near 

the top of the rankings. These emission-based ranking exercises were then combined 

with other factors affecting each sector, such as the potential for future emissions 

reductions, potential for synergistic control of multiple pollutants, significance of MACT 

and NSPS regulations, legal considerations, and population exposure concerns. These 

prioritization exercises are taken into account, together with legal and court-ordered 

timetables, to determine EPA’s regulatory agenda for stationary sources of air pollution. 

Table 1 shows a resultant list of priority sectors.

 

7

A review of these developments can be found in the 2008 EPA report: The Multi-pollutant Report: 

Technical Concepts & Examples, http:epa.gov/airtrends/specialstudies/20080702_multipoll.pdf

8

http://www.epa.gov/ttnecas1/cost.htm
Sector-based Multi-pollutant Strategies 

 7

Table 1. Summary of 2005 National Emission Inventory Emissions for Industrial

Sectors (tons/year)9

Industrial Sector

Criteria Pollutants HAPs 

PM 2.5 VOC SO2 NOX Metal non-Metal

Electric Utilities 530,847 46,885 10,350,289 3,783,214 1,655 401,210

Boilers & Process 

Heaters 107,204 29,890 1,043,454 697,049 1,031 80,005

Ferrous Metals 26,091 17,010 157,508 73,846 1,052 4,896

Pulp and Paper 55,497 139,926 372,534 252,987 56 71,612

Petroleum Refining 30,339 115,112 247,239 146,185 26 9,668

Cement 

Manufacturing 17,388 9,004 157,563 228,112 63 3,353

Clay Products 5,053 2,800 16,716 10,315 92 6,792

Non-Ferrous 

Metals 12,595 11,879 199,550 21,563 194 11,823

Chemical 

Manufacturing 49,743 236,014 191,775 192,764 46 48,635

Oil and Gas 

Production & 

Distribution 14,129 643,352 110,476 1,027,730 32,701

Waste Incineration 6,760 11,776 17,072 52,219 67 12,550

Metal Foundries 24,766 43,014 18,561 16,349 206 3,367

To date, work on the rule prioritization, data integration, and tool development has led 

to the advance of more integrated approaches for industrial sectors. EPA is taking 

advantage of the natural overlap of certain air toxics and criteria air pollutant rules and 

coordinating the development and implementation of MACT and NSPS where it makes 

sense. For example, EPA’s utility sectors strategy will allow a coordinated approach to 

MACT, NSPS and the Clean Air Transport Rule. With regard to refineries and chemical 

manufacturing facilities, OAR is developing more uniform equipment standards for 

common sources of industrial air pollution (e.g. storage vessels, equipment leaks). And, 

as demonstrated by the recent cement sector rulemaking, the sector-based approach 

reduced conflicting and redundant requirements by setting the same particulate matter 

requirement for both the NESHAP and the NSPS (see Appendix B).10

 

9

Elineth Torres, US EPA. Integrated Multi-pollutant Sector-based Approach for the Cement Manufacturing 

Industry. Working Paper, 2011.

10 US EPA. National Emission Standards for Hazardous Air Pollutants from the Portland Cement 

Manufacturing Industry and Standards of Performance for Portland Cement Plants; Final Rule. Federal 

Register, Vol. 75, No. 174, September 9, 2010. http://www.epa.gov/ttn/atw/pcem/fr09se10.pdf
Sector-based Multi-pollutant Strategies 

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In addition to improved coordination within sectors, EPA has been able to coordinate 

across sectors when considering standards for industrial boilers, commercial and 

industrial solid waste incinerators and utilities. EPA also coordinated listening sessions 

for the integration of GHGs in the sector-based approach for utilities and petroleum 

refineries. 

To carry out these approaches, OAQPS is taking these steps.

1. Determine which activities would benefit from such approach and group those 

activities in the corresponding sector.

2. Review the sector’s current and pending regulatory requirements and actions 

across multiple clean air programs in a coordinated manner.

3. Perform integrated, multi-pollutant analyses for the sector.

4. Consolidate regulatory requirements across pollutants and programs for the 

sector, where possible.

5. Identify programmatic incentives and other non-regulatory cross program 

benefits.

6. Improve emission inventories and data systems.

7. Coordinate overlapping CAA mandated compliance timelines and review cycles.

The Clean Air Act Requirements and Opportunities of an Integrated Approach

The CAA Amendments of 1990 address many types of air pollution problems ranging

from urban smog to hazardous and toxic air pollution. As a result of the CAA’s multiple 

legislative goals, a comprehensive system of air quality regulations has been developed 

and implemented. In addition, complex industrial sources of air pollution are usually 

subject to multiple regulatory requirements. Since one important goal of a sector-based 

approach is to reduce conflicting and redundant requirements for industry, it is 

important that, in evaluating a sector, EPA identifies and reviews the multiple regulatory 

actions and requirements in a coordinated manner. Coordinating the timing of 

requirements enables the facility to determine which control technology minimizes the 

overall cost of air pollution control and can help the industry avoid stranded costs 

associated with piecemeal investments in individual control equipment for multiple 

pollutants that might occur otherwise.

The different types of CAA requirements that may apply to a sector, or which may be 

relevant to the sector rulemaking, include, among others: National Emission Standards 

for Hazardous Air Pollutants (NESHAPs), Maximum Achievable Control Technology 

(MACT) Standards, New Source Performance Standards (NSPS), Residual Risk Review, 

and Technology Review (RTR). In addition, coordination of technical and analytical 

efforts for these requirements also supports the enhancement of control technique 

guidelines (CTGs) for sources in areas where CAP emissions exceed health-based 
Sector-based Multi-pollutant Strategies 

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standards in a technically consistent manner. Table 2 shows the CAA requirements for 

direct federal stationary source regulation and guidance.

Table 2. Review and Revision Timeframes for Major Clean Air Act Requirements 

Related to Stationary Source Regulation

In implementing a multi-pollutant sector-based approach, EPA must consider and take 

into account the interactions of multiple CAA regulatory requirements applicable to any 

given sector.

Regulatory Program Review Process Review Timeframe

Section 112

Air Toxics

National Emissions 

Standards for Hazardous Air 

Pollutants (NESHAPs)

Post-1990 NESHAPs called 

Maximum Achievable 

Control Technology (MACT) 

standards

Source category list review Every 8 years

Pre-1990 NESHAP reviews (11 rules) Every 8 years

MACT technology review (96 rules) Every 8 years

MACT residual risk review (96 rules) 8 years after promulgation

Area source rules (47 area source & 12 MACT 

rules cover 70 source categories)

Varies

Area source rules review (70 technology, 12 

residual risk)

Every 8 years

Section 129

Solid Waste Incineration

Technology reviews (5 rules) Every 5 years

Residual risk reviews 8 years after promulgation

Section 111

NSPS

New Source Performance 

Standards to address 

criteria pollutants

NSPS technology review (68 rules) Every 8 years

New NSPS rules 2 years after listing

Section 110

CTG/ACT/183(e)

Control Techniques Guidelines (CTG)/

Alternative Control Techniques (ACT)/

Section 183(e) Consumer Products Rules

Varies

Title 1 Parts C & D

NSR

New Source Review

Permitting review of control technology 

requirements; best available control 

technology (BACT) or lowest achievable 

emissions rate (LAER)

Triggered by source-specific 

construction or 

modifications

Section 169A

Regional Haze SIPs

State Implementation Plans

Best available retrofit technology (BART) 

reviews

Every 8 years
Sector-based Multi-pollutant Strategies 

 10

National Emission Standards for Hazardous Air Pollutants (NESHAP) and New 

Source Performance Standards (NSPS)

NESHAPs are technology-based stationary source standards for HAPs, pollutants that are 

known or suspected to cause cancer or other serious health effects or adverse 

environmental effects. For each new NESHAP, EPA is required to define the Maximum 

Achievable Control Technology (MACT) standard based on the top performing facilities 

in that sector. The NSPS is an emission standard prescribed for criteria pollutants from 

certain stationary source categories. By evaluating the regulatory requirements across 

pollutants (e.g., HAPs, CAPs, GHG) for a sector, and by performing an integrated, multipollutant analysis, EPA can identify control technologies that would best achieve multipollutant emission reductions while minimizing costs. In an integrated, multi-pollutant 

approach, EPA also assesses the applicable and necessary monitoring requirements to 

reduce administrative and compliance complexities associated with complying with 

multiple regulations. Within a rulemaking, EPA strives to ensure that, where monitoring 

is required, methods and reporting requirements are consistent in the NSPS and 

NESHAP for regulated pollutants that have similar characteristics and similar or identical 

emission sources. 

Residual Risk Standards and Technology Reviews (RTR)

RTR is a combined effort to evaluate both risk and technology as required by the CAA 

eight years after the application of MACT standards. For source categories emitting 

known, probable, or possible carcinogens, if the existing MACT standard does not 

“reduce lifetime excess cancer risks to the individual most exposed to emissions from a 

source in the category or subcategory to less than one in a million,” EPA must 

promulgate standards for that source category. In addition, EPA must also review the 

technology requirements “no less often than every 8 years,” as required by CAA section 

112(d)(6). 

To integrate and align the current regulations and future regulatory requirements, EPA 

must determine how the NESHAP and/or NSPS under consideration relate to RTR

requirements applicable to the sector. In developing a rulemaking, EPA would consider 

the potential risk reductions that would be required, as well as any revisions to the 

technology-based standard, and identify opportunities for aligning these with the other 

regulatory requirements.

National Ambient Air Quality Standards (NAAQS)

Under the NAAQS program EPA regulates six CAPs: particulate matter (PM), ozone (O3), 

nitrogen oxides (NOx), sulfur dioxide (SO2), lead (Pb), and carbon monoxide (CO). Those 

areas in the country that exceed these health-based ambient air standards are 

designated as nonattainment areas. For these areas, attaining the standard by reducing 

emissions of criteria pollutants and their precursors is of great importance. A NESHAP or 

NSPS rulemaking that directly, or as a co-benefit, results in additional emission 
Sector-based Multi-pollutant Strategies 

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reductions of CAPs and their precursors will help areas around the country attain these 

NAAQS.

New Source Review (NSR)

The NSR program requires new major stationary sources of air pollution and major 

modifications to major stationary sources to obtain an air pollution permit before 

commencing construction. Permits for sources in attainment areas are referred to as 

prevention of significant air quality deterioration (PSD) permits; while permits for 

sources located in nonattainment areas are referred to as nonattainment permits. 

Collateral CAP emission reductions resulting from the application of MACT may, in 

certain circumstances, be used for “netting” or “offset” purposes under the NSR 

program. “Netting” refers to the process of considering certain previous and 

prospective emissions changes at an existing major source over a contemporaneous 

period to determine if a “net emissions increase” will result from a proposed 

modification. If the “net emissions increase” is significant, then major NSR applies. 

Section 173(a)(1)(A) of the Act requires that a major source or major modification 

planned in a nonattainment area obtain emissions reductions called “offsets” as a 

condition for approval. These offsets are generally obtained from existing sources 

located in the vicinity of the proposed source and must offset the emissions increase 

from the new source or modification and provide a net air quality benefit. 

Under certain circumstances, reductions of HAPs under a MACT may be available for 

NSR netting or offset purposes, where the form of the HAP is emitted as a criteria 

pollutant (e.g., PM2.5). Consistent with an integrated, multi-pollutant sector-based 

approach, EPA would identify these opportunities and take them into account in 

development of the regulations.

Regional Haze and Reasonable Progress 

The purpose of the regional haze program is the prevention of any future, and the 

remedying of any existing, impairment of visibility in mandatory national park and 

wilderness areas which impairment results from manmade air pollution. Under the 

regional haze regulations, states must submit a state implementation plan (SIP) to show 

how they will progress toward attainment of the visibility standard. A SIP must address 

several key elements, including Best Available Retrofit Technology (BART), reasonable 

progress, and long-term strategies. 

A potential benefit for some facilities in a sector is that the technology requirements in, 

for example, a NESHAP rulemaking, could potentially satisfy a facility’s BART 

requirements under the regional haze program. A rule may establish a framework for 

states to include certain control measures or other requirements in their regional haze 

SIPs where such a program would be “better than BART.” 
Sector-based Multi-pollutant Strategies 

 12

Additionally, the level of control achieved through a NESHAP or NSPS may contribute 

toward, and possibly achieve, the visibility improvements needed to satisfy the 

reasonable progress requirements, or incremental visibility improvements, of the 

regional haze rule. Consistent with the integrated, multi-pollutant sector-based 

approach, EPA would consider whether a non-BART-related rulemaking controlling 

emissions which may affect visibility would have an impact on regional haze.

Many Types of Industry Sectors

The U.S. economy is comprised of, and EPA develops regulations for, a number of types 

of sectors. One type of sector can be characterized by a single primary emission source. 

For example, the cement sector’s main emission source for HAPs, CAPs and greenhouse 

GHGs is the cement kiln. While other emissions occur at a typical cement facility (i.e., 

mobile source emissions, emission from the limestone quarry, and storage), the 

combustion and calcination processes in the kiln produce the primary source of multipollutant emissions. For this type of sector, a multi-pollutant approach could streamline 

emission source definitions, regulatory timelines as well as regulated pollutants based 

on the primary emission point identified. See Appendix B for a full discussion.

A second type of sector may take the form of a set of activities or emission sources 

involved in the production of a product or a group of products, where not all of the 

activities involved are necessarily co-located (i.e., located within a facility fence line). 

The iron and steel sector is an example of a sector that integrates multiple processes to 

produce one product. This sector can be characterized as an integrated system of 

mainly three processes (i.e., coke ovens, integrated iron and steel facilities, and electric 

arc furnaces at mini-mills) that together make one product—steel.

A third type of sector can be characterized by the grouping of similar sources in facilities 

that are co-located. For example, refineries and chemical plants are complex facilities 

that contain hundreds of emission points of HAPs and CAPs. These emission points

include combustion sources such as boilers and process heaters, flares, and 

miscellaneous catalyst activities that require catalyst regeneration via combustion (e.g., 

cracking units), as well as evaporative loss sources such as storage tanks, leaking 

equipment (e.g., heat exchangers, piping components), wastewater treatment units, 

miscellaneous atmospheric venting operations, and transfer and loading sources.

It is important that multi-pollutant approaches take this variety of sectors into account. 

Appendix C presents a more lengthy consideration of sector types by further describing 

the iron and steel and chemical manufacturing industrial sectors and integrated 

approaches. 
Sector-based Multi-pollutant Strategies 

 13

IV.A Framework for Considering Sector-based, Multi-pollutant 

Opportunities

The Work Group notes that the presence and nature of opportunities to advance multipollutant approaches to air regulations will vary substantially across industrial sectors. 

This section presents a framework, including a set of questions, that the Work Group 

has developed that could be used to explore multi-pollutant opportunities within 

specific industry sectors. The purpose of pursuing sector-based multi-pollutant 

approaches is to achieve equal or better environmental and public health protection at 

lower overall cost across air pollutants. Costs include those incurred by regulated 

entities to control emissions and assure compliance with applicable requirements as 

well as those incurred by government agencies to develop, promulgate, implement, and 

enforce air requirements within sectors. To achieve this purpose, the Work Group 

identified two overarching questions that should be asked regarding specific industrial 

sectors (see Figure 1). 

To help address these overarching questions, the Work Group identified seven areas 

where there may be opportunities to achieve greater environmental and public health 

benefits at lower cost through enhanced coordination or alignment across various air 

pollutant regulatory programs relevant to a particular industry sector. These potential 

opportunity areas are listed in Figure 2.

 

The Work Group identified a series of questions that could be asked within each of 

these seven areas to determine the specific types of opportunities that may be relevant 

to consider within a specific industry sector. These questions are listed in Figure 3.

Multi-pollutant Opportunity Areas (Figure 2)

1. Timing and sequencing of regulations and requirements

2. Source definition and scope of applicable requirements

3. Monitoring and data

4. Reporting and record keeping

5. Emissions control technology and approaches

6. Energy use and efficiency improvement

7. Community-focused strategies

Overarching Questions (Figure 1)

How might a sector-based, multi-pollutant strategy optimize the reduction of 

air pollution for the sector?

What might optimization look like when considered in terms of emissions 

reduction, risk and impacts reduction, environmental justice, cost reduction, 

certainty, and operational and compliance flexibility?
Sector-based Multi-pollutant Strategies 

 14

Multi-pollutant Opportunity Area Questions (Figure 3)

1. Timing and sequencing of regulations and requirements

How could the timing and sequencing of air pollution regulations (NSPS, NESHAPs, NAAQS, NSR, 

etc.) be better coordinated in the sector?

2. Source definition and scope of applicable requirements

What are the best ways to group emissions sources in the sector for the purpose of coordinated 

regulation and emissions control?

Are there opportunities to reduce the number of regulated emissions sources at a facility by 

combining similar types of operations or units?

Are there significant sources of air pollutants in the sector that are not covered by the scope of 

current regulations?

3. Monitoring and data

Could emission monitoring technologies and policies facilitate multi-pollutant approaches?

Can fence-line or other community-based monitoring approaches be used to advance multipollutant strategies by enhancing understanding of actual ambient concentrations near a facility?

4. Reporting and record keeping

How could record keeping and reporting requirements be harmonized in a sector approach?

Are there opportunities to pursue record keeping and reporting approaches that satisfy a variety 

of pollutant-specific regulatory requirements?

5. Emissions control technology and approaches

Which advanced technologies (process and/or emissions control technologies) could assist in 

controlling multiple types of air pollution in the sector?

Are there trade-offs with regard to air emissions or multi-media environmental impacts (e.g., air, 

water, hazardous waste) that arise from pursuing one technology versus another?

Are there steps that can be taken to support more rapid technology adoption and equipment 

replacement?

What role could work practice standards play in a multi-pollutant control strategy?

6. Energy use and efficiency improvement

What is the interaction between energy utilization and efficiency efforts and conventional air 

pollution control strategies?

Would different regulatory strategies help increase energy efficiency or reduce fuel consumption 

and achieve greater emissions reductions?

7. Community-focused strategies

How can multi-pollutant, sector-based strategies best support efforts to understand and address 

health risks and impacts to communities, including vulnerable populations?

How can multi-pollutant approaches advance the consideration and reduction of cumulative 

health risks and impacts?

How can unintended consequences of integrated strategies be identified prior to 

implementation?

Should integrated, multi-pollutant approaches require unique community involvement and 

communication strategies?
Sector-based Multi-pollutant Strategies 

 15

For each potential opportunity identified using the questions above, it is important to 

consider the benefits and challenges that may be associated with them. The Work 

Group identified several categories of benefits and/or challenges that are useful to 

assess. In some cases, measures may be available to counter or mitigate adverse effects 

of pursuing a particular multi-pollutant approach. The Work Group identified three 

main categories (and associated questions) of benefits and challenges that may arise 

when considering opportunities to advance a multi-pollutant approach. See Figure 4 for 

a list of the categories and questions.

Categories of Benefits/Challenges (Figure 4)

Public and Environmental Health

1. Environment and public health impacts

How will the multi-pollutant approach affect emissions across all categories of air 

pollution (e.g., criteria pollutants, hazardous air pollutants, greenhouse gas 

emissions)?

How will the approach affect overall facility environmental performance, including 

in other media areas (e.g., water, waste)?

How will the approach affect the consideration and reduction of human and 

ecosystem health risks and impacts?

2. Environmental justice

How will the approach affect disproportionally-disadvantaged or vulnerable 

populations or environmental justice considerations?

How transparent would the approach and its outcomes, when implemented, be to 

the interested public and local communities?

Economics and Administrative Efficiency

3. Economic impacts and operational efficiency

How will the approach affect regulatory compliance and pollution control costs in 

the sector?

How will the approach affect economic performance and competitiveness?

How will the approach affect the adoption of new technologies? 

4. Regulatory efficiency

How will the approach affect federal, state, tribal, and/or local government 

resources related to air program implementation?

5. Ease of implementation

How easy would the approach be to implement by regulated sources?

How easy would the approach be to implement, including inspection and 

enforcement, by federal, state, tribal, and local air agencies?

Consistency with the Clean Air Act

6. Legal feasibility

Can the Clean Air Act be reasonably interpreted to accommodate the proposed 

approach?

What is the likelihood that the approach will face and pass legal challenge?
Sector-based Multi-pollutant Strategies 

 16

V. Observations

This section provides expanded discussion on opportunities to advance multi-pollutant 

approaches to address air emissions in industrial sectors. The section summarizes 

observations on how multi-pollutant approaches can fit within sector-based regulatory 

initiatives and then explores the seven multi-pollutant opportunity areas outlined in the 

framework, drawing on observations and examples from the two sector roundtable 

discussions and other CAAAC Work Group discussions.

First Steps: Opportunities Before Multi-Pollutant Approaches

Discussions during the two industry roundtables revealed that substantial opportunities 

remain in some sectors to improve implementation of current regulatory approaches. 

Many roundtable participants emphasized that it is important to pursue such

improvement opportunities in parallel with current efforts to advance innovative multipollutant approaches in specific industry sectors. The Work Group identified specific 

areas of opportunity outside of multi-pollutant approaches, including:

Timely and clear guidance. Participants encouraged EPA to place a high priority 

on efforts to ensure that guidance on rule implementation and related 

information such as test methods are available simultaneously with the release 

of new or revised standards.

Permitting. Industry participants pointed to continued challenges with 

obtaining air permits in a timely manner. The Work Group noted that there are 

a variety of innovative air permitting approaches—which are available within 

the confines of the current Clean Air Act—that could likely be used more widely 

by sources and permitting authorities to address some of these needs and 

concerns. For example, EPA’s Clean Air Act Title V (permitting) whitepapers 1 

and 2 address a variety of approaches for streamlining and improving the design 

of permits.11 Plantwide applicability limits (PALs), made available through EPA’s 

December 2002 New Source Review (NSR) rulemaking, can give facilities the 

opportunity to make operational changes under a plantwide emissions limit 

without triggering the applicability of NSR.

12 EPA’s September 2009 Flexible Air 

Permitting Rule clarified the use of additional approaches that can reduce 

permitting delays and improve the clarity and simplicity of air permits, such as 

alternative operating scenarios (AOS), advance approval of minor NSR, and 

approved replicable methodologies (ARMs).13 Efforts to expand awareness of 

these approaches among permitting authorities and regulated sources, and to 

develop and test new approaches, would likely reduce costs and improve 

regulatory compliance. There may also be opportunities to consider 

 

11 See Title V White Paper 1 (http://www.epa.gov/ttn/oarpg/t5/memoranda/fnlwtppr.pdf) and White 

Paper 2 (http://www.epa.gov/ttncaaa1/t5/memoranda/wtppr-2.pdf).

12 http://www.epa.gov/NSR/fr/20021231_80186.pdf

13 http://www.epa.gov/NSR/documents/FinalRule2009.pdf
Sector-based Multi-pollutant Strategies 

 17

appropriate strategies for tailoring these approaches for use in specific industry 

sectors.

Several industry participants in the roundtable discussions cautioned that small steps to 

improve regulatory approaches within specific sectors may be most appropriate given 

the “relative comfort” most parties have with current approaches. Roundtable 

participants identified a tiered approach that enables EPA to advance toward expanded 

multi-pollutant approaches as opportunities and trust among stakeholders grows.

Multi-Pollutant Approach Opportunity Areas

The Work Group identified several environmental management Opportunity Areas 

worthy of consideration when developing integrated approaches to air pollution 

control. Activities in these areas may be closely related to each other. For example, 

consideration of the definition of air pollution “source category” may entail alternative 

recordkeeping and reporting procedures, or may involve innovative emission monitoring 

technologies. Opportunity areas considered below are: 

1. Timing and sequencing of regulations and requirements

2. Source definition and scope of applicable requirements

3. Monitoring and data

4. Reporting and record keeping

5. Emissions control technology and approaches

6. Energy use and efficiency improvements

7. Community-focused strategies

1. Timing and Sequencing of Regulations and Requirements

Each Clean Air Act regulatory program—such as NSPS, MACT, SIPs, and NAAQS—has its 

own timeframe for promulgation of and revisions to standards and requirements. For 

example, NSPS and MACT standards’ technology review processes are on an 8 year 

cycle. Efforts to coordinate or align the timing and sequencing of air regulations within 

Tier 3: Innovation

Explore non-traditional approaches that enable greater public 

health and environmental outcomes at lower cost

Tier 2: Flexibility

Create options for complying with regulatory requirements 

that enable facilities to optimize performance while ensuring 

protection of the environment and public health

Tier 1: Clarity

Improve the clarity and consistency of current 

regulatory requirements
Sector-based Multi-pollutant Strategies 

 18

a sector may present opportunities to optimize investments in pollution controls and 

compliance systems, while utilizing common monitoring, record keeping, and reporting 

approaches.

Potential benefits

Coordination of regulatory timelines may lead to additional air pollution 

emission reductions (“co-benefits”) that are not available when regulations are 

pursued independent of each other.

Coordinating pollution control equipment requirements across regulations may 

prevent costly shifts in technology and provide longer time periods before new 

technology investments are required. 

Upfront consideration of potential co-benefit or trade-offs of pollutant 

emissions from different emission control strategies may result in approaches 

that best support public health improvements.

Coordination of regulations and requirements may make it easier to identify 

common approaches to monitoring, record keeping, and reporting that reduce 

compliance burdens and costs.

Potential challenges

Workload challenges at regulatory agencies may make it difficult for sectorfocused teams to develop and release multiple regulations at the same time.

Some regulatory timeframes are set by statute or in response to legal actions, 

and regulatory agencies may have little flexibility to adjust timeframes.

Observations and examples

Work Group and roundtable discussions on timing and sequencing emphasized the 

importance of ensuring that implementation guidance and test methods are released in 

conjunction with new requirements, such as NSPS and NESHAP regulations. Industry 

participants observed that delay in issuing guidance and test methods imposes 

compliance risk burdens and uncertainty as well as costs to adjust compliance 

management systems. 

A key driver for aligning the timing and coordination of regulations affecting a facility or 

emissions unit is to optimize the emissions reduction benefits—and associated public 

health and environmental benefits—that can be derived from facility investments in 

emissions controls and regulatory compliance. Participants voiced a strong desire to 

avoid situations where lack of timing or coordination among regulations targeting the 

same or related emissions units results in implementation of redundant or conflicting 

emission controls or other compliance management systems. Many participants 

expressed an interest to ensure that periodic industry investments in pollution controls 

(involving pollution control equipment and/or changes to production processes) 

leverage substantial public health and environmental benefits while enabling the 

efficient deployment of limited investment capital. Some participants suggested that, if 

properly aligned, the 8 year cycle of NSPS and MACT review could fit well with business 

capital investment horizons.
Sector-based Multi-pollutant Strategies 

 19

In this context, participants discussed the value in aligning the timing and/or 

coordination of technology reviews and revisions to the NSPS and MACT standards that 

apply to similar types of processes or emissions units. Given that some industry sectors, 

such as chemical manufacturing, have numerous NSPS and MACT standards that may be 

applicable within the facility, participants discussed the complexity and workload 

challenges of aligning the timing of numerous standards. Participants suggested that it 

would likely be most feasible to align the timing of standards affecting similar process 

areas or emissions units within a facility, while also keeping an open eye to important 

coordination opportunities that may exist with other areas. For example, there may be 

situations where separate emissions units (with separate applicable requirements) may 

be able to utilize common pollution control equipment or compliance management 

systems. For example, Appendix D depicts the past and future regulatory landscape for 

the petroleum refinery sector including major air regulations as well as relevant 

milestones in the development of national ambient standards (NAAQS). 

Failure to align the timing of revisions of NESHAPs and NSPS standards can result in 

situations where facilities are required to comply with older, outdated requirements in 

one standard that are, in effect, obsolete as a result of requirements in the newer 

revised standard. Aligning the timing of revisions could help to purge outdated 

requirements and simplify compliance obligations. A few participants suggested that 

the Obama Administration’s January 18, 2011 Executive Order on Improving Regulation 

and Regulatory Review may provide an opportunity to identify areas where such 

alignment among sector-focused air regulations could be improved.14 Several 

participants observed that it is also important to work with air permitting authorities to 

understand the importance of purging obsolete requirements from permits when they 

are issued or renewed. For example, representatives from iron and steel companies 

cited examples of facility air permits that included numerous obsolete and outdated 

requirements that can create confusion and uncertainty.

Another area affecting timing is the periodic revisions to the NAAQS and resulting 

changes to source-specific requirements associated with State Implementation Plans 

(SIPs). Some participants observed that revisions to the NAAQS should inform a 

coordinated, periodic updating of the NESHAPs and NSPS standards so that these three 

programs become mutually-reinforcing. They noted that the timing of SIP revisions 

could be generally aligned with the roughly decadal review and revisions to NESHAPs 

and NSPS standards.15 Other participants noted that direct coordination and alignment 

 

14 http://www.whitehouse.gov/the-press-office/2011/01/18/improving-regulation-and-regulatory-reviewexecutive-order

15 Section 109(d)(1) controls the NAAQS revision process. It reads: “*A+t five-year intervals thereafter, the 

Administrator shall complete a thorough review of the [Section 108 air quality criteria and the Section 

109(a) NAAQS] and make such revisions in such criteria and standards and promulgate such new standards 

as may be appropriate . . . .” Bound up in the revision directive is one non-discretionary duty and one 
Sector-based Multi-pollutant Strategies 

 20

with the NAAQS is difficult given the complexity of the SIP process that states use to 

translate national criteria pollutant standards into specific measures to control 

emissions within states. Participants observed that there are numerous factors that 

affect the timing of SIP development and the implementation of source-specific 

emissions controls that may be required by a SIP. While efforts to align the timing of 

NAAQS and SIP revisions may not be feasible, regulators could consider how current and 

anticipated changes to the NAAQS may affect emissions controls relevant to specific 

NESHAPs and MACT standards when revising these standards in order to optimize 

approaches.

Finally, participants observed that the New Source Review (NSR) program is another air 

regulatory program that can trigger new requirements, including pollution control 

technology review and adoption. Under NSR, however, the timing of requirements is 

driven on a case-by-case basis by facility construction or modifications. While BACT or 

LAER requirements triggered by NSR may be discordant with coordinated revisions to 

the NESHAPs or NSPS standards, a few participants indicated that plantwide applicability 

limits (PALs) may be appropriate for some sources to align pollution control technology 

reviews and upgrades. A few participants also suggested that future discussions could 

explore opportunities to develop “presumptive BACT or LAER” determinations that 

might align with new NESHAP and/or NSPS standards for some period of time.

Strategies to consider

Intensify efforts to coordinate timing of NSPS and NESHAP/MACT standards. 

Establish explicit work process steps to review previously issued regulations 

affecting emissions units and consider them when developing or revising air 

regulations, utilizing a “checklist” of questions (similar to those presented in the 

Framework section) to guide consideration of alignment opportunities.

Consider how anticipated revisions to the NAAQS may affect SIP requirements 

addressing emissions controls for the sector and take into timing of SIP updates 

with other source category regulatory developments.

When promulgating new NSPS and NESHAP regulations, release implementation 

guidance and test methods simultaneously with the regulations to increase 

consistency and create certainty for industry and implementing air agencies.

2. Source Definition and Scope of Applicable Requirements

The scope of operations covered under the definition for an air pollution source or 

emission unit presents another area of opportunity to pursue multi-pollutant 

approaches. Aligning how sources are defined across regulatory programs affecting 

 

discretionary duty. The non-discretionary duty is for the Administrator to complete a thorough review of 

the criteria and NAAQS every five years. The discretionary duty is for the Administrator to revise the criteria 

and NAAQS as may be appropriate. That is to say, while the Administrator must review these standards 

with regularity, the timing of revisions are wholly within her judgment, subject only to judicial review under 

the arbitrary and capricious standard of review. (Traylor, August 2010, p. 22)
Sector-based Multi-pollutant Strategies 

 21

similar operations within a sector, such as the NESHAP and NSPS programs, may 

enhance the clarity and simplicity of regulatory approaches addressing multiple 

pollutions. Taking a more expansive view of how sources and emission units are defined 

may also facilitate innovative approaches to allow greater operational flexibility that 

translates into measurable reductions in emissions, risk, and impacts at lower cost. In 

some sectors, there may also be opportunities to adjust source definitions and the 

scope of requirements to address sources of air emissions that have not previously been 

regulated but that pose significant risk or impacts to the environment and public health. 

[Is there an example of a successful redefinition of source category that could be added 

here?]

Potential benefits

Combining regulations that address similar operations can create a simpler 

regulatory system that reduces redundancy across regulations in ways that 

makes it easier for sources to manage compliance with applicable requirements.

Aligning the source definitions across various regulatory programs, such as NSPS 

and NESHAPs, may make it easier to see and address multi-pollutant 

opportunities to coordinate or align specific emission control, monitoring, 

record keeping, testing, or reporting requirements.

Expanding the definition of source or emission unit to cover previously 

unregulated sources of air emissions (which may exist in some sectors) can 

address substantial risks and impacts to public health and the environment.

Potential challenges

If sources and emissions units are defined too expansively, it may be difficult for 

permitting authorities and regulated facilities to understand whether and how a 

regulation is applicable to a facility’s operations.

Incorporating new, previously unregulated sources of air emissions into the 

definition of source and emission units covered under various regulatory 

programs may pose substantial costs or challenges for emission control and 

compliance.

Observations and examples

The extent and value of opportunities to adjust source definitions varies substantially 

across sectors. Participants suggested that it may be useful to look for opportunities to 

combine similar regulations within specific regulatory programs (e.g., NESHAP, NSPS) in 

sectors or types of operations where numerous standards or regulations exist. For 

example, the chemical manufacturing sector has numerous NESHAP and NSPS standards 

that cover similar types of operations. [What specific examples can we provide to 

highlight this point?] Participants also indicated that there may also be opportunities to 

reduce the number of regulations addressing storage tanks by modifying source 

definitions.

When looking at potential adjustments to the source definition within one regulatory 

program, it is important to look for opportunities to align this source definition across 
Sector-based Multi-pollutant Strategies 

 22

regulatory programs (at least across the NSPS and NESHAP programs). This is already 

envisioned in the Clean Air Act. The NSPS source category definition provides an 

important cross-link to the NESHAPs program, because Section 112(c)(1) provides that 

“*t+o the extent practicable, the categories and subcategories listed under this 

subsection [112(c)] shall be consistent with the list of source categories established 

pursuant to section 7411 of this title and part C of this subchapter.”16 [What additional 

discussion with specific examples or opportunities would be helpful to add? To what 

extent is this already done? Where are source definitions aligned and about the right 

scope? Where are they not aligned and too narrow in their scope?]

In the context of permitting individual sources within a sector, there may also be 

creative opportunities in the context of NSR to consider a more expansive, facility-wide 

definition of source for pollutants. The plantwide applicability limit or PAL concept 

promulgated by EPA in 2002 provides a useful example of how taking a facility-wide 

perspective on multiple types of air pollutant emissions can both enhance operational 

flexibility and create incentives for emission reductions.17 It is important for such 

facility-wide approaches to consider local impacts related to the NAAQS and hazardous 

air pollutants, to avoid issues such as “hot spots” that may pose unacceptable risks or 

impacts. Innovative permitting approaches have been developed and piloted, such as 

HAP screening protocols or fence line monitoring, that enable use of facility-wide 

approaches with appropriate safeguards.

Finally, there may be some sectors where research and monitoring reveal that 

significant amounts of air emissions are released from aspects of operations that are not 

currently addressed by regulatory programs. For example, presentations to the CAAAC 

on air pollutant regulations in the oil and gas sector (covering exploration, development, 

and transport, but not refining) indicated that there are likely significant emissions of 

methane and other air pollutants from some aspects of sector operations that are not 

currently addressed by air regulations. Efforts to adjust source definitions and the scope 

of applicable requirements to address such unregulated sources of emissions may bring 

substantial benefits for air quality and public and ecosystem health. Such steps may 

assist in meeting requirements associated with other air quality goals such as meeting 

the NAAQS or regional haze goals. In addition, identifying and controlling previously 

uncontrolled sources may result in a more economical overall strategy for a facility. 

Strategies to consider

Identify and pursue opportunities within the NSPS and NESHAP programs to 

reduce the number of unit-specific regulations that may be relevant to sources 

 

16 Traylor (August 2010), p. 20.

17 For a discussion of experiences with PALs and other types of plantwide emissions limits, see US EPA, 

Evaluation of Implementation Experiences with Innovative Air Permits: Results of the U.S. EPA Flexible 

Permit Implementation Review, 2002. http://www.epa.gov/ttn/caaa/t5/memoranda/iap_eier.pdf
Sector-based Multi-pollutant Strategies 

 23

within particular sectors, while looking for opportunities to align source 

definitions and scope across the NSPS and NESHAP programs.

Work with permitting authorities and regulated sources to explore 

opportunities to expand use of facility-wide approaches that afford greater 

operational flexibility and create incentives for emissions reduction while 

safeguarding against adverse local impacts.

Continue efforts to identify and address significant sources of air pollution 

within sectors which are not currently covered by the scope of current 

regulations.

3. Monitoring and Data

Monitoring and data can support multi-pollutant approaches in a variety of ways. First, 

when looking across different air regulations that may address the same process or 

emission units, there may be opportunities to harmonize monitoring and data collection 

approaches in ways that provide commensurate information at lower cost. Second, the 

use of innovative monitoring approaches may help improve understanding of how 

facility operations affect local community air quality and resulting human and 

ecosystem health risks and impacts. Such understanding may facilitate creative 

opportunities to approach the control and management of multiple pollutants in a 

manner that best reduces risk and health impacts at lower cost. In cases where there 

are trade-offs in pollutant emissions across different control technologies or strategies, 

monitoring approaches can provide safeguards to ensure that the risks and impacts of 

selected approach are appropriate managed.

Potential benefits

Improving the consistency of monitoring and data collection requirements 

across pollutants and regulatory programs may reduce compliance burdens and 

costs while providing sufficient information.

Innovative monitoring technologies and strategies can help identify multipollutant approaches that afford the greatest reduction of human and 

ecosystem health risks and impacts at the lowest cost.

Expanded use of monitoring approaches can provide data that could be used to 

improve the accuracy of models.

Potential challenges

Deployment of some monitoring technologies and systems can be costly.

Various factors, such as the placement of monitors and the maintenance and 

calibration of monitors, can affect the ability of monitoring to provide a 

comprehensive and accurate picture of ambient pollutant concentrations and 

local exposure and health risks and impacts.

Monitoring strategies and data collection needs can vary substantially across 

pollutants, making it difficult to devise consistent approaches across 

regulations.
Sector-based Multi-pollutant Strategies 

 24

Observations and examples

Participants indicated that there may be opportunities to improve coordination and 

alignment of monitoring and data requirements across regulations, such as the NSPS 

and NESHAPs, affecting similar emission units. For example, there may be opportunities 

to align the frequency of monitoring, averaging times, data compilation formats, QA/QC 

approaches, or other aspects of monitoring and data requirements. [Are there any 

specific examples that highlight these types or opportunities or that point to where this 

is being done well? Are there experiences from the cement sector rulemakings that 

could be discussed here?]

New monitoring technologies and approaches, including continuous emissions monitors 

(CEMS) and fence line ambient concentration monitors, can support multi-pollutant 

approaches that lower risk and impacts as well as compliance costs. New monitoring 

approaches could be used to facilitate multi-pollutant emissions reduction strategies in 

which there may be trade-offs among different pollutant emissions depending on the 

control technology or approach used. Similarly, new monitoring approaches may be 

useful to increase stakeholders’ comfort with the use of facility-wide approaches which 

afford facilities greater operational flexibility, building trust in the local community that 

public health is being adequately safeguarded. In addition, the use of new monitoring 

technologies like CEMS can eliminate the cost and burden of having numerous 

monitoring requirements focused on specific components of an emission unit.

Work Group participants discussed how the experience of one chemical manufacturing 

facility in Houston with advanced monitoring investments illustrates the potential for 

enhanced community protection efforts. The TPC Group (formerly called Texas 

Petrochemicals) operates a chemical plant in the Houston, Texas, one of a handful of 

chemical plants located within the boundaries of the City of Houston along the Ship 

Channel. One of the main products from the plant is 1,3-butadiene, emissions of which 

are a hazardous air pollutant as defined by the Clean Air Act.

Although the facility is subject to the MACT hazardous organic NESHAP (HON) rule and 

had implemented HON controls in the mid-1990s, concentrations of 1,3-butadiene 

measured by TCEQ’s monitor at nearby Milby Park, a city park located immediately 

northwest of the facility, remained higher than desirable in 2004 and early 2005. In 

2004, the monitor measured an annual average of 4.0 parts per billion (ppb). In 2005, 

TPC entered into a voluntary emissions reduction agreement with TCEQ targeted at 

reducing emissions of 1,3-butadiene. As a result of several projects implemented by 

TPC and additional work at another (unrelated) nearby facility, levels of 1,3-butadiene at 

Milby Park dropped to 1.54 ppb in 2005 and 0.59 ppb in 2010. TPC’s emissions of 1,3-

butadiene reduced by more than 75 percent, or almost 70 tons per year.
Sector-based Multi-pollutant Strategies 

 25

TPC’s emission reductions of 1,3-butadiene were due to the installation of a flare gas 

recovery system and other process improvements18, as well as the installation of a 

sophisticated fence-line monitoring technology. The facility installed Fourier-Transform 

Infrared (FTIR) systems to continuously scan a 400-meter distance along its north and 

south fence-lines. Together, the two systems address prevailing wind directions and 

help to provide an additional measure of protection for nearby residential communities. 

The facility responds to a “hit” of the fence-line system at 15 ppb 1,3-butadiene. Facility 

shift supervisory personnel receive email alerts for a “hit”, and immediately embark on 

an all-out search to locate and address any source of emissions. Hand-held devices such 

as the Forward Looking Infrared (FLIR) camera (“gas-find” camera) and highly sensitive 

VOC monitors (ppbRAE) provide supplemental tools for tracking down unusual or 

unexpected sources. The new monitoring technology has allowed the facility to operate 

a more stringent leak detection and repair program (LDAR) and conduct equipment 

maintenance and change-overs with significantly reduced associated emissions.

TPC’s 1,3 butadiene emissions reduction efforts have also served to reduce emissions of 

other chemicals, where reductions came “along for the ride.” For example, emissions of 

all Highly Reactive VOC (HRVOC) chemicals were reduced by an estimated 168 tons per 

year, and emissions of point source (non-fugitive) HRVOC chemicals were reduced by an 

estimated 58 tons per year.

In addition to improvements in facility monitoring technology that may help optimize 

emission control investments at industrial facilities, several participants observed that 

emissions and air quality dispersion models themselves may often overpredict pollution 

levels, resulting in higher cost for pollution controls and/or compliance systems. They 

indicated that facility air permitting that requires modeling sometimes makes it difficult 

to comply with standards which otherwise might be easy to achieve based on 

monitoring data. For example, a Flint Hill Resources facility had a PM continuous 

monitor at a facility in a rural area at which they decided to do a new project and model 

emissions. The modeling results showed they were significantly over levels for PSD, but 

monitoring was showing they were well below levels. The expanded use of emissions 

and ambient air quality monitoring should improve understanding of multi-pollutant 

emissions levels and modeling approaches. [How can we enhance the multi-pollutant 

aspects of monitoring approaches that complement modeling?]

Strategies to consider

When developing or revising rules, EPA should examine the specific monitoring 

and data collection requirements included in other regulations and guidance 

 

18 TPC installed a flare gas recovery system that accounts for the majority of emissions reductions. The 

facility previous flared continuously, and now has less than a handful of short-duration flaring events per 

year. Total flare emissions of 1,3-butadiene were reduced by approximately 90 percent. Other pollution 

control investments included a new “dry break” rail car hose technology that eliminated venting of rail car 

loading emissions.
Sector-based Multi-pollutant Strategies 

 26

relevant to the process or emission unit to see if there are opportunities to align 

or coordinate approaches.

[Are there steps that permitting authorities or regulated sources could take to 

ensure that permit requirements incorporate a well-aligned approach to 

monitoring and data collection for specific emissions units or process areas?]

Document and share case studies of creative approaches for using new 

monitoring approaches to enable multi-pollutant approaches.

4. Reporting and Record Keeping

Record keeping and reporting requirements embedded in regulations affecting similar 

units present another area of opportunity for more efficient and effective multipollutant approaches. By aligning and coordinating specific aspects of record keeping 

and reporting, such as frequency, units of measurement, data elements, and format, 

compliance management systems can be simplified. Greater alignment and consistency 

of record keeping and reporting can reduce compliance burden and costs while 

decreasing errors, providing benefits to both regulated facilities and permitting 

authorities. Many opportunities in this area are likely to be administrative in nature, 

without environmental or public health implications.

Potential benefits

Record keeping and reporting burden and costs can be lowered when regulated 

facilities can increase use of consistent approaches and avoid the need to shift 

among approaches when operating scenarios change.

Improved alignment of record keeping and reporting may reduce errors and 

improve accuracy.

Efforts to improve consistency and reduce complexity may also enhance 

understanding and the usefulness of multi-pollutant compliance information.

Potential challenges

Efforts to drive enhanced consistency may reduce the usefulness of information, 

if differences in record keeping and reporting approaches arise from the nature 

of specific needs.

Work is needed to ensure that consistent approaches in regulations get 

translated into consistent approaches in the context of facility air permits. 

Overcoming legacy record keeping and reporting requirements contained in 

permits may be difficult to adapt and align with new approaches.

Observations and examples

Participants observed several areas where there are likely to be opportunities for 

combining and integrating record keeping and reporting approaches relevant to related 

emissions sources within a sector. Some areas include:

NESHAPs relevant to the chemical manufacturing sector;

NSPS, MACT, and hazardous organic NESHAP (HON) standards relevant to 

storage tanks; and

[What other specific opportunity areas could be added here?]
Sector-based Multi-pollutant Strategies 

 27

Participants described how current record keeping and reporting approaches in some 

sectors can be complex, particularly when alternative modes of operation trigger 

different applicable requirements. For example, some participants described how a 

facility may have above-ground storage tanks that switch between two different 

services subject to HON, NSPS, and MACT standards. Record keeping and reporting 

frequencies and content can change for each standard for each mode of operation—a 

tank could be subject to two out of the four requirements at one time, then three out of 

the four at another. [What information could be added to improve the detail and 

accuracy of this example?]

Participants observed that Title V air permits are the place where a variety of 

regulations get translated into the set of specific record keeping and reporting 

requirements with which facilities must comply. One industry representative suggested 

that MACT standards (and other air pollutant regulations) could be written to provide 

permitting authorities some latitude to align MACT reporting dates with other reporting 

dates required in the Title V permit so that facilities aren’t faced with numerous 

different reporting deadlines. [Is there a good example that would illustrate this need?]

Participants also described situations where federal and state record keeping and 

reporting requirements sometimes differ or conflict. For example, one industry 

representative commented that a conflict emerged between the HON and state rules 

about appropriate averaging time (daily versus hourly) for the required CEMS at the 

facility. [Are there other examples? How might these discrepancies between state and 

federal rules be addressed?] 

Strategies to consider

When developing or revising rules, EPA should examine the specific record 

keeping and reporting requirements included in other regulations and guidance 

relevant to the process or emission unit to see if there are opportunities to align 

or coordinate approaches.

Investigate opportunities to allow permitting authorities some flexibility to align 

the timing (e.g., due dates) of MACT standard reporting obligations with other 

relevant Title V reporting timeframes.

Encourage permitting authorities and regulated sources to explore 

opportunities to simplify and improve the consistency of record keeping and 

reporting requirements contained in air permits when permits are developed or 

renewed.

5. Emissions Control Technologies and Approaches

Emission control technologies and approaches represent perhaps the greatest area of 

potential for optimizing reductions of multiple air pollutants at lower cost. Lack of 

coordination among regulatory programs can result in situations where facilities must 

invest in one control system to satisfy one requirement and then turn around a few 

years later to invest in a different (and potentially incompatible) control technology to 

meet the requirements of a regulation addressing a different pollutant in the same 

process area. In some cases emission controls designed to reduce emissions of one 
Sector-based Multi-pollutant Strategies 

 28

pollutant may actually increase the release of other pollutants. This piecemeal 

approach to deploying control technology can result in an inefficient use of capital, 

while also producing suboptimal emissions reduction outcomes.

By coordinating and aligning emission control strategies across regulatory programs 

within a sector, multi-pollutant reduction co-benefits may be highly cost-effective. In 

addition, in sectors where there may be promising new process technology or emission 

control technologies on the horizon that demonstrate potential to reduce multiple 

pollutants, it may be feasible to coordinate and align regulations across pollutant 

programs to support more rapid adoption of the technology within the sector.

Potential benefits

Greater levels of emissions reduction may be achieved across multiple types of 

pollutants at lower cost.

Coordination of pollution control requirements across regulations within a 

sector may enable longer capital investment horizons that increase costeffectiveness and certainty for regulated facilities.

Alignment of pollution control requirements may help secure reductions of 

multiple pollutants (as co-benefits) sooner than would otherwise be required.

Coordination of pollution control requirements within a sector may help 

regulators make more informed decisions in cases where emission control 

approaches pose trade-offs among pollutants.

Coordination of pollution control requirements may enable regulators to 

encourage adoption of advanced process or pollution control technologies that 

hold potential for cost-effective multi-pollutant reductions.

Potential challenges

Developing and testing novel advanced pollution control and process 

technologies can be expensive and pose significant financial and compliance 

risks, even if there is substantial promise for emissions reductions.

For some pollution control systems, there are real trade-offs between 

greenhouse gas emissions and emissions of other pollutants.

Observations and examples

Industry representatives observed that many pollution control technologies are costly. 

This means that regulated facilities are typically interested to ensure (with reasonable 

certainty) that investments they make in controls will satisfy environmental compliance 

requirements for some reasonable period of time. Other participants observed that 

there may be cost-effective opportunities to require emission controls that substantially 

benefit public health, and that installation of such controls should not necessarily be 

held hostage by past investments in pollution controls. Efforts within sectors to 

consider technology options that can control multiple pollutants may reveal important 

opportunities to maximize returns on investments in pollution controls.

EPA has supported research efforts to identify viable multi-pollutant emission control 

options relevant to some industry sectors. For example, EPA sponsored a 2005 report 

that analyzed 27 existing and novel control technologies designed to achieve multi-
Sector-based Multi-pollutant Strategies 

 29

pollutant reductions (of SO2, NOx, and mercury) for coal-fired electric generating units.

19

While emissions reduction performance varied across control technologies, some types 

of controls exhibited potential to significantly control all three types of pollutants. This 

type of research can be useful to identify existing and emerging technology options that 

may optimize control of multiple pollutants at lower costs within a sector. [Are there 

other sectors for which analyses of multi-pollutant benefits of alternative control 

options have been conducted? What experiences from the EGU and the cement sectors 

can be summarized here—for example, what did the analyses in these sectors reveal 

and how has this information been used in the context of rulemaking?]

The availability of advanced technology with emissions reduction potential can vary 

substantially across industry sectors. Some sectors have active research programs to 

research, develop, pilot, and scale up advanced technologies that improve 

environmental performance. [Are there any specific examples we can reference aside 

from the DOE Industries of the Future program that is mentioned in the next section?] 

In other sectors, there may be few (if any) emerging process or emission control 

technologies that have potential to transform emission reduction opportunities. 

However, there may be other changes or trends on the horizon that may affect 

operations and air emissions within the sector. For example, a major area of change in 

the chemical manufacturing sector involves the transition from fossil-based feed stocks 

to more renewable, bio-based feed stocks.

In some cases there may be advanced technologies which hold significant promise for 

reducing emissions within a sector. Facilities are often reluctant to invest in these 

technologies, however, until there are proven examples of the technology performing in 

scale-up settings. Piloting a new technology at full-scale production levels, however, 

can be tremendously costly and also carry substantial risk of non-compliance with 

environmental regulations. Failure to meet compliance levels for all relevant 

parameters (e.g., pollutant capture efficiency) can result in non-compliance and the 

need to install other tested pollution control equipment, even if the novel system 

performs optimally from a multi-pollutant perspective.

Participants indicated that there may be steps EPA and state, tribal, and local regulatory 

agencies can take to “create space” for experimentation with promising emerging 

technologies. One participant indicated that efforts to develop and pilot an innovative 

emissions reduction technology in the pulp and paper sector in Virginia in the early 

2000s, although ultimately unsuccessful, provides a valuable model for how to engage 

multiple stakeholders to “create space” for innovation that can have major multipollutant emissions reduction benefits. [What additional information could we add on 

this pilot project (involving International Paper)?]

Participants also observed that NSR-driven technology requirements can sometimes fit 

awkwardly into technology approaches driven by NESHAP and NSPS standards. At times 

there may be alignment, such as when control technologies identified as satisfying NSRrequired Best Available Control Technology (BACT) and the same as those identified as 

 

19 US EPA. Multipollutant Emission Control Technology Options for Coal-fired Power Plants. EPA-600/R05/034. March 2005. http://www.epa.gov/airmarkets/resource/docs/multipreport2005.pdf
Sector-based Multi-pollutant Strategies 

 30

satisfying MACT standards. However, over time, divergence can emerge with BACT and 

MACT requiring different types of emission controls. [What additional information 

would be useful to discuss here? Are there any examples of where this has occurred? 

Are there steps that should be taken to enhance alignment between BACT/LAER and 

MACT and NSPS control technology requirements?]

[What can we say about the role of work practice standards relevant to multi-pollutant 

strategies?]

Finally, participants noted that there can be substantial trade-offs in emission control 

performance across pollutants. Trade-offs can be particularly salient between 

greenhouse gas emissions and other pollutants. For example, some pollution control 

equipment (e.g., thermal oxidizers) involves incineration of air pollutants to break down 

their harmful properties. While these emission controls decrease volatile organic 

compound (VOC) and other emissions, they can increase CO2, SO2, and NOx emissions, 

particularly when natural gas is added to ensure proper combustion. [What additional 

detail can we add on specific technologies that illustrate the trade-offs? What 

technologies may provide a non-GHG-emitting alternative to thermal oxidizers? It 

would be helpful to include an example that highlights an “energy penalty” associated 

with air toxics controls (e.g., the energy related increases in NOx emissions).] At 

present, there are not clear guidelines to assist regulators in reconciling trade-offs 

among pollutants. Several participants observed that pollution control trade-offs can 

extend to the multi-media sphere—between air, water, and waste. For example, some 

pollution control systems are effective at removing contaminants from the air, but these 

same captured contaminants may pose water quality or waste challenges.

Strategies to consider

When developing or revising rules, EPA should consider opportunities to align or 

coordinate emissions control requirements and approaches across various 

regulatory programs.

Consider conducting joint government-trade association-industry efforts to 

assess the multi-pollutant emission control attributes of existing and novel 

pollution control equipment and process technologies within specific sectors.

Consider and develop options to encourage piloting of novel emissions-reducing 

technologies within industry sectors. Explore whether supplemental 

environmental projects, temporary exemptions, variances, or other approaches 

could be used to spur piloting of promising emissions reduction technologies.

6. Energy Use and Efficiency Improvement

Opportunities to reduce energy use are an increasingly important consideration in the 

context of multi-pollutant reduction strategies within industry sectors. Combustionbased energy use is a major source of greenhouse gas emissions, as well as criteria air 

pollutants and hazardous air pollutants. At the same time, energy use can be a 

significant expense in some industry sectors. Investments in energy efficiency, however,

may reduce emissions levels for multiple pollutants without requiring any additional 

emission control costs. In some cases, pollution control approaches may actually 
Sector-based Multi-pollutant Strategies 

 31

increase greenhouse gas emissions. As EPA and its partners continue to explore sectorbased, multi-pollutant emissions reduction strategies, it is vital to ensure that energy 

use and greenhouse gas emissions are considered in efforts to optimize overall emission 

reductions. 

Potential benefits

Energy efficiency improvements typically result in lower emissions of 

greenhouse gases, as well as some criteria air pollutants and hazardous air 

pollutants. 

Reductions in energy use can result in substantial financial benefits.

Potential challenges

For some pollution control systems, there are real trade-offs between 

greenhouse gas emissions and emissions of other pollutants.

Air permitting can sometimes pose barriers to making energy efficiency 

upgrades.

Substantial increases in energy efficiency may require development and 

financing of new technology.

Observations and examples

Industry participants observed that substantial progress has been made in reducing 

energy use across many sectors, including iron and steel and chemical manufacturing, 

over the past decade. While industry participants noted that companies in energyintensive sectors often have strong cost drivers for reducing energy use, other 

participants noted that several studies suggest that substantial energy use reduction 

opportunities remain across many industrial sectors in the U.S.20

Participants observed that some sectors have active research programs to research, 

develop, pilot, and scale up advanced technologies that improve environmental 

performance. For example, under the auspices of the World Steel Association CO2

Breakthrough Programme, active research is underway to research and develop 

“breakthrough technologies” that could dramatically reduce the environmental 

footprint, including air emissions, or the iron and steel sector.21 In the U.S., the 

American Iron and Steel Institute (in collaboration with the U.S. Department of Energy) 

is similarly working to advance innovative, breakthrough technologies, such as molten 

oxide electrolysis and hydrogen flash melting, which promise near zero CO2 emissions. 

While some innovations may be decades from commercial application, these efforts 

highlight the importance of considering longer-term advanced technology development 

initiatives when designing coordinated multi-pollutant regulatory approaches. As 

promising low-emissions technologies move closer to commercial use, sector-specific 

regulations could be tailored to speed adoption and diffusion.

 

20 For example, see McKinsey & Company. Unlocking Energy Efficiency in the U.S. Economy, July 2009, 

http://www.mckinsey.com/en/Client_Service/Electric_Power_and_Natural_Gas/Latest_thinking/Unlocking

_energy_efficiency_in_the_US_economy.aspx.

21http://www.worldsteel.org/pictures/programfiles/Fact%20sheet_Breakthrough%20technologies.pdf
Sector-based Multi-pollutant Strategies 

 32

In some cases, conflicting unit-specific standards have the potential to limit certain 

energy efficiency projects. For example, a representative from an iron and steel 

company described how boiler MACT requirements prevented a facility from diverting 

process waste gas from a flare to use as a fuel for its boiler. Although this project would 

have increased emissions from the boiler, net facility emissions would have decreased 

as a waste stream would have been converted to productive use for energy generation. 

Participants observed that efforts are need to develop creative approaches to address 

these types of opportunities.

Strategies to consider

When developing or revising rules, EPA should consider opportunities to align or 

coordinate emissions control requirements and approaches across various 

regulatory programs with energy efficiency opportunities.

Explore creative opportunities to eliminate regulatory and permitting barriers to 

energy efficiency projects that do not increase net emissions and do not 

increase health risks and impacts.

7. Community-Focused Strategies

Sector-based, multi-pollutant approaches may open unique opportunities to address 

local environmental risks and impacts in creative ways. Use of new monitoring 

strategies can give the regulated facility, regulators, and community members a better 

understanding of risks and impacts associated with facility air emissions, while informing 

development of controls strategies that optimize investments. Collaborative 

approaches that engage members of the local community can also build trust and 

communications pathways that enable consideration of permitting approaches that 

accommodate more regulatory flexibility and innovation. The combination of new 

monitoring and collaborative approaches may spur opportunities to drive substantial 

reductions in local public health risks and impacts—looking across the full range of air 

pollutants—while also safeguarding against adverse effects that may arise if trade-offs 

emerge.

Potential benefits

Community-focused strategies align local efforts to identify and manage the 

sources of greatest risk and impacts to public health and community well-being, 

enabling more substantial reductions in emissions that impact the community.

Improved trust and communication pathways between regulated facilities and 

local community members can provide a foundation for addressing a broad 

range of environmental and public health challenges that may arise.

Collaborative efforts with the local community may enable cost-effective risk 

reduction that improves the financial performance of the enterprise, supporting 

local economic prosperity and job retention or creation.

Potential challenges

Effective development of community-focused strategies that engage local 

community members in meaningful ways can take substantial time and effort to 

build.
Sector-based Multi-pollutant Strategies 

 33

There may be insufficient information regarding local air quality, exposure, and 

health impacts to enable productive discussion about community-focused 

strategies for controlling multiple air pollutants.

Establishment of robust monitoring systems can be costly.

Consideration of the cumulative health risks resulting from community member 

exposure to environmental stressors may open difficult and potentially 

polarizing debate regarding the broader future of economic activity in a 

community.

Communication about human health risks and impacts associated with air 

quality can be challenging and may be impeded where scientific understanding 

is less certain.

Observations and examples

CAAAC Work Group members discussed the importance of pursuing community-focused 

strategies that can enable flexibility and innovation, resulting in lower emissions and 

human and ecosystem health impacts at lower cost. Participants observed that 

community-focused strategies often begin with regular and meaningful opportunities 

for interested community members to meet with representatives from the regulated 

facility and permitting authority to share and discuss information, concerns, approaches, 

and action plans. Increasingly, the use of innovative monitoring technologies and 

approaches can enhance understanding of ambient air quality or even estimates of 

exposure and health risks or impacts. Monitoring, when paired with an effective 

collaborative process that builds trust and understanding, can produce emission control 

strategies that reduce health risks and impacts from multi-pollutant emissions more 

rapidly and at lower cost than otherwise might be possible.

Participants recognized that some communities may have sensitive populations and 

socio-economic factors that exacerbate the health impacts of exposure to pollutants

and environmental stressors. Environmental justice (EJ) initiatives typically seek to 

address and mitigate these types of situations where communities experience 

disproportionate impacts to health and well-being.22 Some participants observed that a 

major concern of EJ communities is that cumulative impacts from multiple air pollutants 

and sources are not taken into consideration during development and implementation 

of air quality standards and permitting processes. The California Environmental 

Protection Agency has defined cumulative impacts as: “Exposures, public health or 

environmental effects from the combined emissions and discharges, in a geographic 

area, including environmental pollution from all sources, whether single or multi-media, 

routinely, accidentally, or otherwise released.”

23

 Multi-pollutant approaches may create 

 

22 The concept of environmental justice (EJ), as defined by EPA, is the fair treatment and meaningful 

involvement of all people regardless of race, color, national origin, or income with respect to the 

development, implementation, and enforcement of environmental laws, regulations, and policies. See 

http://www.epa.gov/compliance/ej/index.html

23 CAL. EPA, Addressing the Issues of Cumulative Impacts and Precautionary Approach in the Ej Pilot 

Projects 1 (2005), available at:

http://www.calepa.ca.gov/EnvJustice/ActionPlan/PhaseI/March2005/CI_PA.pdf
Sector-based Multi-pollutant Strategies 

 34

opportunities to focus compliance requirements to deliver greater reductions in health 

risks and impacts across multiple air pollutants at lower cost and greater speed.

Consideration of multi-pollutant approaches may also highlight trade-offs that are 

important for communities to discuss and navigate. For example, control measures that 

reduce GHG emissions but exacerbate PM emissions may have a disproportionately 

adverse impact on public health in the local community. While coordination of sectorfocused regulations at the national level can help navigate potential trade-offs in 

pollutant emissions, it may be important to allow some flexibility for local communities 

(involving regulated source, permitting authority, and interested community members) 

to weigh and select control strategies that balance trade-offs to minimize local health 

risks.

EPA is taking steps to provide meaningful opportunities for community involvement in 

air permitting processes. A future goal for the Agency, as described in Plan EJ 2014, is to 

focus on permits issued that enable EPA to address the complex issue of cumulative 

impacts from exposure to multiple sources and existing conditions that are critical to the 

effective consideration of EJ in permitting.24 To this end, EPA plans to work closely with 

program and regional offices, states, tribes, and community stakeholders and develop a 

common mapping platform and nationally consistent screening and targeting tool to 

enhance EJ analysis and decision-making. 

Participants identified a range of considerations that should be factored into efforts to 

develop community-focused, multi-pollutant strategies. These include:

Potential trade-offs in pollutant emissions associated with different emissions 

control strategies;

Importance of plain language communication;

Need to clarify what pollutants are emitted and in what quantities;

Understanding of how emissions will be monitored and reported, and how 

standards and emissions limits and other requirements will be inspected and 

enforced;

Need to communicate how to interpret the risk to human health posed by 

emissions;

Understanding of the role interested members in the community can play in 

decision-making processes and what specific involvement opportunities exist

(e.g., public comment);

Understanding of unique characteristics of each community affected (e.g., 

demographics, socioeconomic status, other polluting facilities in the area, 

previous history/experience with EPA and industry, etc.); and

Lessons learned from past projects.

 

24 http://www.epa.gov/compliance/ej/plan-ej/index.html
Sector-based Multi-pollutant Strategies 

 35

Strategies to consider

Develop case studies of model community-focused approaches (including those 

involving innovative monitoring technologies and collaborative processes) that 

have sought to advance multi-pollutant emission control strategies that 

optimize reductions in health risks and impacts. Share these case studies with 

permitting authorities and industry sector organizations to encourage broader 

consideration, use, and experimentation involving community-focused 

strategies.

Provide input to environmental justice initiatives and activities EPA is involved 

with to highlight opportunities and challenges associated with multi-pollutant 

considerations.

[What other strategies should be considered?]
Sector-based Multi-pollutant Strategies 

 36

VI.Conclusions

The Work Group identified several conclusions from its discussions.

First, the time is right to look at ways to advance multi-pollutant approaches within 

sectors. We have more than 20 years of experience with developing unit-specific air 

standards related to criteria and hazardous air pollutants. We are now able to conduct 

more sophisticated sector-wide assessments of air emissions. Given the complexity of 

the current regulatory landscape and potential costs of achieving further reductions in 

air emissions within sectors, particularly as energy efficiency and greenhouse gas 

emissions reductions are considered, the time is ripe to take a more rigorous look at 

opportunities to align and optimize the various air regulations affecting individual 

sectors.

Second, multi-pollutant approaches promise benefits in many sectors, although the 

challenges to moving towards multi-pollutant approaches are real and will require 

effort by EPA, industry, and other stakeholders to overcome. The primary benefits

anticipated include better environmental and public health outcomes at lower cost to 

business and government. Sector-based multi-pollutant approaches also promise a

regulatory system that reduces redundancy across regulations, enhances compliance 

with applicable requirements, and improves trust and communication between 

regulated facilities and local community members. The challenges of moving to multipollutant approaches are real and will take substantial time and work to navigate. Given 

that there is substantial familiarity with the current system, efforts must proceed 

carefully to develop and demonstrate the viability and benefits of new approaches.

Third, the opportunity to advance multi-pollutant approaches will vary substantially 

between industries. Sector-specific approaches are needed. While some learning can 

be transferred across sectors, progress will require careful, sector-specific exploration 

and initiative. A variety of policy innovations will be required.

Fourth, an incremental approach to exploring and implementing new sector-based, 

multi-pollutant approaches is underway and should continue within the confines of the 

existing Clean Air Act. As discussed in this report, EPA has begun to explore and 

develop multi-pollutant approaches within several priority sectors. The following 

section summarizes the Work Group’s recommendations to EPA for evolving and 

expanding these efforts.
Sector-based Multi-pollutant Strategies 

 37

VII. Recommendations

The Work Group identified several recommendations to EPA which the Work Group 

believes will enhance the effectiveness and value of sector-based, multi-pollutant 

efforts. The first two recommendations address approaches to improve the process of 

pursuing sector-based, multi-pollutant strategies. Recommendations 3 through 6 

address specific opportunity areas which the Work Group believes are ripe for 

exploration. The final recommendation addresses opportunities to improve the 

implementation of existing regulation within the context of permitting and guidance. 

These recommendations are outlined below.

1. EPA should expand efforts to advance multi-pollutant clean air approaches 

within sectors. Each multi-pollutant sector-based effort should include 

consideration of criteria pollutant, hazardous pollutant, and greenhouse gas 

emissions. EPA should:

a. Build on current efforts by EPA OAQPS to pursue sector-based, multipollutant opportunities within identified high-priority sectors; and

b. Use the information developed in multi-pollutant approaches to 

develop innovative policies and emission control strategies that will 

maximize improvements to public health and the environment.

2. EPA should establish a clear and transparent process for considering and 

advancing multi-pollutant clean air approaches within sectors. The process 

should ensure that clean air regulations are developed in full consideration of 

the existing and pending regulatory requirements for that sector. EPA should:

a. Consider the Framework in this report to identify and assess the 

opportunities to advance multi-pollutant approaches within specific 

industry sectors. The Framework includes an assessment of a full range 

of parameters (e.g. public health, legal, environmental, economic, 

enforcement, feasability);

b. Conduct periodic informal, multi-stakeholder, sector-focused 

roundtables to explore opportunities within individual sectors. 

Roundtables conducted independent of specific regulation 

developments may identify multi-pollutant opportunities more easily 

than forums focused on input to specific regulatory actions;

c. Maintain a clear timeline or roadmap for each sector that clarifies the 

“state of play” with regard to regulatory development within each 

major industrial sector; and

d. Seek public comment on multi-pollutant, sector-based approaches prior 

to, as well as during, regulatory development opportunities.

3. EPA should expand engagement with environmental justice communities and 

companies in specific sectors to develop and demonstrate innovative multipollutant approaches that seek to reduce facility-specific, as well as cumulative, 

risks and impacts. EPA should:

a. Consider the implications of multipollutant, sector-based approaches in 

its EJ 2014 initiative; and
Sector-based Multi-pollutant Strategies 

 38

b. Document case studies of innovative approaches to community 

monitoring and efforts to address trade-offs and reduce multi-pollutant 

risks.

4. EPA should work to identify and quantify air pollution co-benefits and trade-offs 

associated with multi-pollutant regulatory approaches. EPA should:

a. Develop strategies for expanding co-benefit opportunities and 

strategies for reducing negative trade-offs associated with multipollutant approaches; and 

b. EPA should develop principles that could guide community input into 

decisions regarding trade-offs and co-benefits.

5. EPA should explore opportunities to simplify industrial source category 

definitions in order to advance multi-pollutant reduction strategies. EPA should:

a. Identify specific areas or sectors where rethinking of source definitions 

may be particularly useful; and

b. Identify the technical, legal and environmental implications of source 

category definitional change.

6. EPA should explore, develop, and test integrated approaches to multi-pollutant 

monitoring, record keeping, and reporting that harness the capabilities of new 

monitoring and information technologies. EPA should:

a. Develop approaches that could enable facilities to adopt alternative 

monitoring approaches that could address the needs of multiple 

regulations (including state or tribal regulations); and

b. Explore the use of continuous emission monitors (CEMs) and other 

monitoring technologies that might enable simplified reporting of 

electronic data, uniform emission inventories, and facilitate 

simultaneous compliance with multiple regulatory requirements while 

also improving emission inventories.

7. EPA should intensify its efforts to improve basic implementation of industrial 

sector clean air regulatory programs at the federal, state, tribal and local levels, 

while pursuing multi-pollutant approaches. EPA should:

a. Expand awareness and diffusion of innovative permitting approaches 

that can address challenges within specific sectors;

b. Consider the expanded use of plantwide applicability limits (PALs), and 

other flexible permitting approaches which are currently available 

under the Clean Air Act that could improve environmental benefits and 

lowers compliance costs; and

c. Ensure that implementation guidance is provided simultaneously with 

new rules.