UNITED STATES ENVIRONMENTAL PROTECTION AGENCY RESEARCH TRIANGLE PARK, NC 27711 

### AUG 10 2005

OFFICE OF 

### MEMORANDUM AIR QUALITY PLANNING AND STANDARDS 

### SUBJECT: Consideration

# ofMultipl~· Pol

# ~(Sin¥n ol Strategy Development StephenD. Page, Director 

# l·---( <- 

### Office ofAir Quality**Pl~** 

### ing and**Stan~s** 

### (C404-04) FROM:

TO: Air DivisionDirectors, Regions I-X
I am writing to update you on our efforts to support multipollutant approaches in developing state implementationplan (SIP) control strategies and to enlist your support in encouraging States to start moving towards the development ofsuch strategies. We are asking for your input on the tools and/or guidance needed to support development ofmultipollutant control strategies and for examples ofmultipollutant control strategies and/or multipollutant SIPs that have already been created.
In 

### addition, I am requesting that each Regional office provide us with the name ofa contactpersonby August 22, 2005 to: 1) work with us during the guidance development process; and 2) provide us withrecommendations for tools, information, and guidance needed for developing multipollutant control strategies byAugust 29, 2005.
As you are aware, the National Research Council (NRC) ofthe National Academies formed the Committee on Air Quality Management (AQM) in the United States in response to a congressional request for an independent evaluation ofthe overall effectiveness ofthe CAA. In their January 2004 report, Air QualityManagement in the United States, the Committee made several recommendations. One recommendation was to transform the SIP into a comprehensive air quality management plan (AQMP) that would: 1) encompass all criteriapollutants for which a State has not attained the National Air Ambient Quality Standards; 2) include keyhazardous air pollutants (HAPs); and 3) identify and propose control strategies for air pollution hot spots.
In

### June 2004, the Clean AirAct Advisory Committee (CAAAC) formed the AQM Work Group, which was tasked with assessing the recommendations made in the 2004 NRC report and advising the CAAAC on ways to improve the AQM system in the U.S. Specifically, the CAAAC charged the Work Group with outlining concrete steps that couldpromote change in the direction recommended bythe NRC. The Work Group provided 38 recommendations, and one ofthese, Recommendation 4.1, states that "forthe SIPs States are required to submit over the next several years, EPA and States, locals, and Tribes should promote the consideration of multipollutant impacts, including the impacts ofair taxies, and where there is discretion, select regulatory approaches that maximize benefits from controlling key air taxies, as well as ozone, 

### PMz.s and regional haze." The CAAAC accepted a1138 recommendations and EPA is moving

Recycled/Recyclable • Printed wHh Vegetable 011 Based Inks on 100% Recycled Paper (40% Postconsumer)2

forward to implement them. At its core, Recommendation 4.1 is based onthe NRC's long-term vision ofcreating a multipollutant, integrated AQMP. While multipollutant SIPs are not required bythe CAA, the CAAAC believed that there are opportunities for testing this concept in the short-term.
The SIP planning efforts are already underway for many areas. Clearly, States have a verydemanding schedule for meetingthe SIP submittal deadlines, and they are working with limited resources. However, I believe that States need to move forward in considering multi pollutant control strategies. With a modest amount ofadditional attention, a State could test and/or implementmultipollutant planning approaches during the current SIP planningprocess. Though a multipollutant approach to assessing control strategies would require additional work inthe nearterm, the long-term benefits are likelyto be significant, both environmentally and economically. Bytaking steps toward a multipollutant approach for control strategy development, a State shouldbe able to make betteruse oflimitedresources and improve its ability to develop control strategies that optimize the mix ofcontrols for multiplepollutants.
While there is no federal regulatoryrequirement for States to reduce individual toxic air pollutants to any specific ambient level, there are federal requirements for categories ofsources oftoxic airpollutants, many ofwhich contribute to the formation ofozone, PM2.5, and/or regional haze. We recognize that, bytaking a multipollutant approach, improvements in air quality and human health can be obtained ifair toxics, especiallyhigh-risk air toxics, are reduced. To facilitate the multipollutant approach in SIP development, we are revisiting our approach to regulating toxic airpollutants. For example, we are evaluating opportunities to use the authorities under section 112 ofthe CAA, particularlythe delegation authorities in section 112(1), to facilitate the use ofSIPs forjointplanning for relevant source categories. 

### In this way, States couldmake improvements in air qualitybyconsidering air toxics reduction potential when selecting specific control strategies through the SIP process.
I encourage you to work with the States in your Region to encourage them to starttaking a multipollutant approach in developing control strategies as part oftheir air quality planning. An EPAmultipollutant control strategyteam has been formed which consists ofrepresentatives from the Office ofAir QualityPlanning and Standards (OAQPS), the Office ofTransportation and Air Quality (OTAQ), the Office ofPolicy, Analysis and Review (OPAR), the Office of Atmospheric Program's Clean Air Markets Division (CAMD), and Region V. To provide some immediate assistance to States in initiating multipollutant control strategies, the team has developed the attached 3-page document, "PreliminaryApproach for Identifying Toxic Air Pollutants for Consideration in Multipollutant Control Strategies." The attachment includes: 1) a working definition of"multipollutant control strategy"; 2) an initial list ofkeytoxic air pollutants to consider, as well as a website address that provides a list ofkey area source categories for toxic airpollutants; and 3) a summary description ofan approach that an area can use to develop its own list oftoxic airpollutants with a link to a website describing a more detailed approach to identifying local toxic air pollutants.

### 3

In

### the longerterm, we are planning to develop more detailed and comprehensive guidance on multipollutant control strategy development. With that in mind, we have initiated a pilotproject in Detroit to evaluate multipollutant control strategy development for an urban area. The goal is to incorporate the information gained from this pilot project into additional guidance by early2006.
Before we proceed further with guidance development, I would appreciate your input in two important areas. First, I would like to know your thoughts about the information and/or tools that State, local, and Tribal (S/LIT) groups will need in order to pursue the development of multipollutant control strategies. I would ask that you survey your States for their input as well. Second, we would like information about cases inwhich a S/LIT group has considered multiple pollutants in the process ofdeveloping a SIP and/or has created a ')oint" ormultipollutant SIP. Please send information on any examples ofmultipollutant control strategies and/or multipollutant SIP development to AmyVasu ofmy staff. ByAugust 22,2005, please send an email to Lydia Wegman (wegman.lydia@epa.gov) and to AmyVasu ofmy staff(vasu.amy@epa.gov) with the name ofa contactperson who will provide us with your recommendations and work with us during the guidance development process. I also ask that this contactprovide your recommendations, and those ofyour States, by email to Lydia Wegman and Amy VasubyAugust 29,2005. We will also berequesting input from S/LIT representatives and others at the 2005 AirInnovations conference in Chicago (http://www.cleanairinfo.com/airinnovations2005) during the August 25 breakout session on multipollutant control strategy development. The recommendations you and others provide will inform the EPA team on how best to focus its efforts withregard to further development oftools, information, and guidance to assist S/LIT groups in developing multipollutant control strategies.
In conclusion, I ask that you share this information, as well as the attached summary, with your States and encourage them to take a multipollutant approach in developing control strategies as part oftheir SIPs. Ifyou have any questions, please contact AmyVasu at (919) 541-0107.
Attachment

cc: Joe Paisie Tom Helms PennyLassiter Marypat Tyson (Region V) LydiaWegman

### I. Background

### Preliminary Approach for Identifying Toxic Air Pollutants for Consideration in Multipollutant Control Strategies 8/10/05

In 2002, the National Research Council (NRC) ofthe National Academies formed the Committee onAir Quality Management in the United States inresponse to a congressional request for an independent evaluation ofthe overall effectiveness ofthe Clean Air Act (CAA). In their January2004 report,

### Air QualityManagement in the United States, the Committee made several recommendations. Onerecommendation was to transform the state implementationplan (SIP) into a comprehensive air quality managementplan (AQMP) that would: (1) encompass all criteria pollutants for which a State has not attained the NAAQS; (2) include keyhazardous airpollutants (HAPs); and (3) identify and propose control strategies for air pollutionhot spots.
In June 2004, the Clean Air ActAdvisory Committee (CAAAC) formed the Air Quality Management Work Group, which was tasked with assessing the recommendations made in the 2004 NRC report and advising the CAAAC onways to improve the AQM system in the U.S. Specifically, the CAAAC charged the Work Group with outlining concrete steps that could promote change inthe directionrecommendedbythe NRC. The Work Group provided 38 recommendations, including Recommendation 4.1, which states that "forthe SIPs States are required to submit over the next several years, EPA and States, locals, and Tribes should promote the consideration ofmultipollutant impacts, including the impacts ofair toxics, and where there is discretion, selectregulatory approaches that maximize benefits from controllingkey air toxics, as well as ozone, PM2
.5 and regional haze." The CAAAC accepted these recommendations, and now EPAis moving forward to implement them. Atits core, Recommendation 4.1 is based onthe NRC long-term vision ofcreating a multipollutant, integrated AQMP. While multipollutant SIPs are not requiredbythe CAA, the CAAAC believed that there are opportunities for testing this concept in the short-term.


### II. What is the objective ofthis document?
The objective ofthis document is to provide information to the States to support their moving toward the goal ofmultipollutant SIPs bytaking steps to evaluate multiple pollutants and develop multipollutant control strategies. This document includes: 1) a working definition of "multipollutant control strategy"; 2) an initial list ofkeytoxic air pollutants to consider, as well as a website address thatprovides a list ofkey area source categories for toxic airpollutants; and 3) a summary description ofan approach that an area could use to develop its own list oftoxic air pollutants and source categories. This is intended to be an interim document that will bereplaced within a yearby a guidance document which is currently under development.


### III. What is a multipollutant control strategy?
A multipollutant control strategy is a strategy for reducingpollutant emissions that considers two ormore groups ofpollutants in selecting control strategies, with the goal of selecting a control strategythat optimizes the mix ofcontrols for multiplepollutants. Two or more ofthe following groups ofairpollutants shouldbe included: 1) ozone and its precursors; 2) PM2
.5 and its precursors; and 3) one ormore toxic airpollutants. As an example, in developing a

### multipollutant control strategy for an area that is a nonattainment area for 

### PM2.s,but which is in attainment with the ozone NAAQS, a State might focus on 

### PM2
.5 

### and its precursors, as well as on selected toxic air pollutants that pose high risk and/or contribute to 

### PM2

. 5 

### (as direct 

### PM or as 

### PM2.s precursors).


### IV. Why should a State/local/Tribal entity develop a multipollutant control strategy?
A State/locaVTribal entity should develop a multipollutant control strategy for several reasons:

• to prepare for the future 

### Imove in the direction ofhaving integrated, multipollutant control strategy;

• to assist an area in reaching attainment in a more cost-effective and efficient manner with greater overall reductions ofpollutants;

• to promote an optimal mix ofcontrol measures for multiple pollutants and to avoid control measures that, while beneficial in reducing one pollutant, mayresult in increases in another;

• to betterutilize limited State/locaVTribal resources, and those ofthe regulated community, for improving air quality; and

• to make it easier for potentially affected sources to plan installation ofcontrols, rather than having to install controls in a piecemeal fashion.

V. What are the steps in identifying toxic air pollutants for consideration in developing a multipollutant control strategy?
Once areas, and criteriapollutants ofconcern in those areas, have been identified, a State/locaVTribal entity could use the following three-tiered approach to select toxic airpollutants for consideration in developing a multipollutant control strategy for a particular area. The first tier contains a short list of3 toxic airpollutants that have been identified as national risk drivers bythe National AirTaxies Assessment (NATA) National Scale Assessment for 1999. The second tier includes a list ofsome toxic air pollutants that occur inmany areas ofthe U.S. that, due to emission levels and toxicological properties, maypose high risks. 1 

### The third tierpresents an approach for identifying toxic air pollutants ofconcernthat canbe used for assessing a local area. Additional information onthe 1999 NATANational Scale Assessment will be available in fall 2005 at: http://www.epa.gov/ttn/atw/nata/. 1) Tier 1: Evaluate a "short list" oftoxic airpollutants that are nationally-occurring and that have the potential to pose high risks to human health in urban areas: • Benzene • Acrolein • Diesel 

### PM

1 This is a subset ofthe toxic airpollutants identifiedbythe 1999 NATANational Scale Assessment as "regional risk drivers." More information will be available in fal12005 at: http://www.epa.gov/ttn/atw/nata/.


### 2The file "99 NATA Risk Drivers EI Pie Charts.ppt" (at http://www.epa.gov/air/caaac/aqm.html, under "document library'') contains pie charts showing the source categorycontributions ofemissions for each ofthese toxic air pollutants. Information on area source categories oftoxic airpollutants is provided at: http:1/www.epa.gov/ttn/atw/urban/arearules.html. 2) 

### Tier 2: Consider some additional toxic airpollutants that have beenidentified as being emittedbyexisting sources, as well as having the potential to cause cancer and/or noncancer effects:



### • Arsenic compounds 

### • 1,3-Butadiene 

### • Chlorine 

### • Chromium VI 

### • Coke oven emissions 

### • Formaldehyde 

### • Hydrazine 

### •**~anganese** compounds 

## • Naphthalene 

### • Nickel compounds 

### • PARs 

### • Tetrachloroethylene (Perchloroethylene)
The file "99NATARisk Drivers EI Pie Charts.ppt" (at http://www.epa.gov/air/caaac/aqm.html, under "document library'') contains pie charts showing the source category contributions ofemissions for each ofthese toxic air pollutants. Information on area source categories oftoxic airpollutants is provided at: http://www.epa.gov/ttn/atw/urban!arearules.html. 3) 

### Tier 3: Identify any additional local toxic air pollutants.
Areas can develop their own lists oftoxic air pollutants using the NATAresults by following the step-by-step approach provided in the 3-page file called "Use ofNATA data to Evaluate Area-Specific Toxic Air Pollutants ofConcern" (at http://www.epa.gov/air/caaac/aqm.html, under "document library").
Note that this three-tiered approach focuses on pollutants that present inhalationrisks (since the NATA national scale assessment only accounts for inhalation risks from outdoor pollutants) and, therefore, does not specificallyhighlight other significant pollutants (e.g., mercury) thathave the potential to affect human health and ecosystems. A State/local/Tribal entity could choose to include suchpollutants in their analyses, as well as in their selection of control measures.

3