1 BACKGROUND INFORMATION DOCUMENT

DEVELOPMENT OF HYPOTHETICAL NONATTAINMENT AREAS FOR ILLUSTRATING PROPOSED CLASSIFI CATION THRESHOLDS FOR AREAS DESIGNATED NONATTAINMENT FO R THE 2008 0.075 PPM 8-HOUR OZONE NATIONAL AMBIENT AI R QUALITY STANDARD

Docket ID No. EPA-HQ-OAR-2010-0885

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF AIR AND RADIATION

OFFICE OF AIR QUALITY PLANNING AND STANDARDS

RESEARCH TRIANGLE PARK, NC

January 20122 INTRODUCTION

The EPA is proposing rules to establish clas sification thresholds for nonattainment areas under the 2008 ozone national ambient air quality standard (NAAQS). The proposed rule does not propose to establish attainment or nonatt ainment designations, nor does it address the principles that will be consid ered in the designation process. EPA has already issued guidance concerning designations for the 2008 ozone NAAQS and is following the CAA process for designating areas for the 2008 NAA QS in a separate action.

The Clean Air Act (CAA) specifies certain planning and emission control obligations in accordance with each classification and provide s the maximum attainment date for each classification. To evaluate the potential impact of the proposed classification thresholds, EPA developed a set of hypothetical nona ttainment areas based on the counties that have monitors measuring violations of the 2008 NAAQS base d on a 2010 design value. There a total of 113 counties with monitored 2010 design values th at exceed the 2008 ozone NAAQS of 0.075 ppm. We note that some areas may certify data from 20 11 early so that it can be considered in the designation process; thus the c ounties indentified in this document may not exactly match the counties that are considered violating the 2008 NAAQS for purposes of the designations. For analysis purposes, the counties were grouped in to “hypothetical urban areas” based on the following steps below. Once a site is placed in a hypothetical nonattainment area under a step, it is not considered fo r further steps.

(1) Monitoring sites inside an existing 8-hr ozone nonattainment area boundary designated for the 1997 NAAQS are assigned to that area.

(2) Additional sites inside a county/CBSA/CSA ove rlapping an existing nonattainment area are assigned to that area (i.e . existing nonattainment area is expanded to include those sites).

(3) Remaining sites inside a Comb ined Statistical Area (CSA) are assigned to that CSA.

(4) Remaining sites inside a Core Based Statisti cal Area (CBSA) are assigned to that CBSA.

(5) All remaining sites are assigned to the county in which they reside.

The 2006 definitions of Combined Statistical Areas (CSAs) and Core-Based Statistical Areas (CBSAs) were used for CSA and CBSA boundaries.

The approach proposed in the rulemaking and an alyzed herein is the “Percent-Above-Standard” method concerning classification. The classifications for the hypothetical nonattainment areas are based on the following thresholds:3 Area class Classification Threshold Percent-Above-Standard (ppm)
Marginal From 0.076 up to 1 0.086

Moderate From 0.086 up to 1 0.100

Serious From 0.100 up to 1 0.113

Severe-15 From 0.113 up to 1 0.119

Severe-17 From 0.119 up to 1 0.175

Extreme equal to or above 0.175

1 but not including

It is important to note that EPA’s method for inclusion and grouping of counties into hypothetical nonattainment areas was done sole ly for the purpose of illustrating how the proposed classification schemes discussed might apply to areas designated nonattainment for the 2008 NAAQS. The creation of this set of hypot hetical nonattainment areas, while based on actual air quality data from 2008-2010, is not inte nded to pre-judge the designation process that will occur between now and the time of desi gnation, which could be based on more recent quality assured air quality data if available suffi ciently in advance of th e designations. Thus, the final designations by EPA may include nonattainmen t areas that are not on this list. Similarly, states may recommend and EPA may designate as a ttainment some areas or portions of areas that are on this list. In addition, boundaries of nonattain ment areas could be different than as defined in this list of hypothetical areas. This list should not be constr ued as a proposal by EPA of areas that should be desi gnated nonattainment.

2008 Ozone NAAQS Hypothetical Nonattainment Areas and Classifications Under the Percent-Above-Standard Method

This section presents the hypothetical nona ttainment areas, their 8-hour ozone design values for 2010, and the classifications unde r the Percent-Above-Standard proposal for classification of nonattainment areas under the 2008 8-hour standa rd of 0.075 ppm. Under this proposed classification method, all ar eas would be classified under subpa rt 2 of part D, Title I of the Clean Air Act, according to 8-hour ozone le vels. The 2008 NAAQS classification thresholds would apply to all areas designa ted nonattainment and would be set at the same percentage above the level of the 2008 NAAQS as the 1-hour clas sification thresholds were above the 1- hour standard level as establishe d in the Clean Air Act’s Table 1 (section 181). As a result, all nonattainment areas would be classified as Ma rginal, Moderate, Serious, Severe or Extreme under a revised classification table that is based on a 0.075 ppm 8-hour ozone NAAQS. The table of the classifications and the 8-hour ozone thresholds appear in the proposal.4 Table 1: 2008 Ozone NAAQS Hypothetical Nona ttainment Areas and Classifications Under the Percent-Above-Standard Method

Hypothetical No nattainment Area Design Value 2008-2010 (ppm) Prospective Classification Los Angeles South Coast Air Basin, CA 0.112 Serious San Joaquin Valley, CA 0.104 Serious Sacramento Metro, CA 0.102 Serious Los Angeles-San Bernardino Cos (W Mojave), CA 0.099 Moderate Riverside Co, (Coachella Valley), CA 0.095 Moderate Baltimore, MD 0.089 Moderate San Diego, CA 0.088 Moderate Dallas-Fort Worth, TX 0.086 Moderate Ventura Co, CA 0.086 Moderate Houston-Galveston-Brazoria, TX 0.084 Marginal Nevada Co. (Western Part), CA 0.084 Marginal New York-N. New Jersey-Long Island,NY-NJ-CT 0.084 Marginal San Luis Obispo-Paso Robles, CA 0.084 Marginal Amador and Calaveras Cos (Central Mtn), CA 0.083 Marginal Kern Co (Eastern Kern), CA 0.083 Marginal Mariposa and Tuolumne Cos (Southern Mtn), CA 0.083 Marginal Philadelphia-Wilmington-Atl. City , PA-NJ-MD-DE 0.083 Marginal
Charlotte-Gastonia-Rock H ill, NC-SC 0.082 Marginal Pittsburgh-Beaver Valley, PA 0.081 Marginal Washington, DC-MD-VA 0.081 Marginal Atlanta, GA 0.080 Marginal San Francisco Bay Area, CA 0.080 Marginal Red Bluff, CA 0.080 Marginal Chico, CA 0.079 Marginal Greater Connecticut, CT 0.079 Marginal Cincinnati-Hamilton, OH-KY-IN 0.079 Marginal Reading, PA 0.079 Marginal Baton Rouge, LA 0.078 Marginal Boston-Lawrence-Worcester (E. Mass), MA 0.078 Marginal Denver-Boulder-Greeley-Ft Collins-Love., CO 0.078 Marginal Imperial Co, CA 0.078 Marginal Sheboygan, WI 0.078 Marginal Sublette County, WY – COUNTY 0.078 Marginal Jamestown, NY 0.077 Marginal Phoenix-Mesa, AZ 0.077 Marginal Springfield (Western MA), MA 0.077 Marginal St. Louis, MO-IL 0.077 Marginal
Cleveland-Akron-Lorain , OH 0.077 Marginal Columbus, OH 0.077 Marginal Knoxville, TN 0.077 Marginal Lancaster, PA 0.077 Marginal Las Vegas, NV 0.076 Marginal Providence (All RI), RI 0.076 Marginal5 Hypothetical No nattainment Area Design Value 2008-2010 (ppm) Prospective Classification Sutter Co (Sutter Buttes), CA 0.076 Marginal Allentown-Bethlehem-Easton, PA 0.076 Marginal Memphis, TN-AR 0.076 Marginal Richmond-Petersburg, VA 0.076 Marginal Greensboro--Winston-Salem--High Point, NC 0.076 Marginal Greenville-Spartanburg-Anderson, SC 0.076 Marginal Gulfport-Biloxi-Pascagoula, MS 0.076 Marginal Nashville-Davidson-Murfreesboro-Columbia, TN 0.076 Marginal Santa Barbara-Santa Maria-Goleta, CA 0.076 Marginal