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Proposed Rule

Clean Air Act Area Designations; California

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Environmental Protection Agency (EPA).


Proposed rule.


EPA is proposing to make minor changes in the boundaries between areas in Southern California established under the Clean Air Act for purposes of addressing the national ambient air quality standards (NAAQS) for 1-hour ozone, particulate matter (PM-10), carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2), and the prior NAAQS for total suspended particulate matter (TSP).

We are taking comments on this proposal and plan to follow with a final action.


Any comments must arrive by September 15, 2003.


Please address your comments to: Dave Jesson, Air Planning Office (AIR-2), Air Division, EPA, Region IX, 75 Hawthorne Street, San Francisco, CA 94105-3901, or to

A copy of the State's submittal is available for public inspection during normal business hours at EPA's Region IX office. Please contact Dave Jesson if you wish to schedule a visit. A copy of the submittal is also available at the following location: California Air Resources Board, 1001 “I” Street, Sacramento, CA 95812.

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Dave Jesson, EPA Region IX, at (415) 972-3957, or

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Throughout this document, “we,” “us,” and “our” refer to EPA.

I. Background

A. Current Area Boundaries, Designations, and Classifications

Areas of the country were originally designated as attainment, nonattainment, or unclassifiable following enactment of 1977 Amendments to the Clean Air Act (“CAA” or “the Act”). 43 FR 8962 (March 3, 1978). These designations were generally based on monitored air quality values compared to the applicable NAAQS.

On November 15, 1990, the date of enactment of the 1990 CAA Amendments, each ozone and CO area designated nonattainment, attainment, or unclassifiable immediately before enactment of the Amendments was designated, by operation of law, as a nonattainment, attainment, or unclassifiable area, respectively. CAA section 107(d)(1)(C). The specific boundaries of the areas were determined subsequently based on requests by each state and final determinations by EPA. 56 FR 56694 (November 6, 1991). Ozone and CO nonattainment areas were also given classifications according to the design values prescribed in the 1990 Amendments. CAA sections 181(a)(1) and 186(a)(1), respectively.

PM-10 areas meeting the requirements of either (i) or (ii) of CAA section 107(d)(4)(B) were designated nonattainment for PM-10 by operation of law and classified “moderate” at the time of enactment of the 1990 CAA Amendments. EPA later designated additional PM-10 nonattainment areas (see, for example, 58 FR 67335, December 21, 1993) and amended the initial classifications in accordance with CAA section 188(b).

SO2 and NO2 areas designated as nonattainment or attainment/unclassified before enactment of the 1990 CAA Amendments retained those designations by operation of law. CAA section 107(d)(1)(C)(i) and (ii), respectively.

Area boundaries and (for ozone, CO, and PM-10) area classifications have been amended over the years under the Start Printed Page 48849applicable CAA provisions, either by request of each state, by operation of law, or by EPA initiative. For the State of California, the current area designations and classifications are codified at 40 CFR 81.305. For historical reference, this regulatory section also includes designations for TSP, a NAAQS which was replaced in 1987 when we promulgated the PM-10 NAAQS.

B. California's Request for Area Changes

Under CAA section 107(d)(3)(D), the Governor of any state, on the Governor's own motion, is authorized to submit to the Administrator a revised designation of any nonattainment area or portions thereof within the State.[1] On November 18, 2002, the California Air Resources Board (CARB) submitted to EPA a request under CAA section 107(d)(3)(D) to revise the boundaries of the Los-Angeles-South Coast Air Basin Area (“South Coast Air Basin”) and the Southeast Desert Air Basin.[2] The purposes of CARB's request are to:

(1) Enlarge the South Coast Air Basin to include the Banning Pass area, thereby excluding the area from the Southeast Desert;

(2) harmonize the PM-10 and ozone boundaries of the Coachella Valley area [3] by changing the ozone area boundaries to match the PM-10 area boundaries; and

(3) correct the eastern boundary of the South Coast Air Basin with respect to CO.

II. EPA Review of the State's Request

A. Applicable Criteria

In determining whether to approve or deny a state's request for a revision to the designation of an area under section 107(d)(3)(D), we use the same factors Congress directed us to consider when we initiate a revision to a designation of an area on our own motion under section 107(d)(3)(A). These factors include “air quality data, planning and control considerations, or any other air quality-related considerations the Administrator deems appropriate.”

B. Expansion of the South Coast Air Basin to Include the Banning Pass

The Banning Pass area in Riverside County is also known as the San Gorgonio Pass area. The area is a mountain saddle about 15 miles long by 5 miles wide in northwestern Riverside County. There are only 4 communities in this area: Banning, Beaumont, Cabazon, and Cherry Valley. This area is currently part of the Southeast Desert severe-17 ozone nonattainment area and the Coachella Valley serious PM-10 nonattainment area, and the area has been designated as attainment or unclassifiable with respect to CO, NO2, SO2, and TSP.[4] The populated portion of the Southeast Desert-Coachella Valley area is primarily low desert. Palm Springs is the largest community, and tourism and agriculture are the major industries in the Coachella Valley.

The South Coast Air Quality Management District (SCAQMD) has local jurisdiction over the South Coast Air Basin, the Banning Pass area, and the Coachella Valley portion of the Southeast Desert. Both CARB and SCAQMD conclude that the Banning Pass area is more similar to the South Coast Air Basin in climate and topography and measured air quality, and that air pollution levels within the Banning Pass area are far more heavily influenced by emissions originating in the South Coast Air Basin than in the Southeast Desert-Coachella Valley.

The climate of the Banning Pass area closely resembles the “steppe” (semi-arid) climate of the South Coast Air Basin in terms of rainfall and temperature. Precipitation levels recorded in the Banning Pass are much higher than those of the Coachella Valley, which has a “desert” (arid) climate classification. For example, the annual average rainfall is 17 inches in Beaumont, and only 5.2 inches in Palm Springs. On average, summer temperatures in the Coachella Valley are 10-15 degrees F warmer than those recorded at the Banning Pass and in the central South Coast Air Basin. The mean temperature in Palm Springs for July is 92 degrees F, compared to 77 degrees F in Beaumont.

Pollution from western and central portions of the South Coast Air Basin is typically transported eastward by prevailing ocean breezes. This results in high ozone concentrations measured in mountain sites at the eastern boundary of the basin, including Banning (elevation 2300 feet), which recorded a total of 25 exceedances with a design value of 0.143 parts per million (ppm) during the period 1999 to 2001. During this same period, Palm Springs (elevation 200 feet) recorded only 7 exceedances, with a design value of 0.128 ppm. Similarly, the Banning Pass is much more closely linked to the South Coast Air Basin than to the Southeast Desert with respect to emissions and ambient concentrations for the other pollutants, such as NO2 and SO2.

In terms of ozone generation, the South Coast Air Basin has far greater emissions than the Southeast Desert generally and the Coachella Valley specifically, and the easterly direction of the prevailing winds also ensures that elevated pollution levels in Banning Pass are a consequence of the air mass shared with the western and central portions of the South Coast Air Basin, and are not associated with the Coachella Valley or other portions of the Southeast Desert.

For these reasons, the Banning Pass area was moved to the South Coast Air Basin under State law in 1996. CARB and SCAQMD therefore request that the Federal boundaries be adjusted to match the boundaries used for State air quality purposes, by moving the Banning Pass area from the Southeast Desert-Coachella Valley area to the South Coast Air Basin.

The table below labeled “Banning Pass Area” shows the current federal designations and classifications of this area, and the changes that would result from approval of the State's proposed revision. Start Printed Page 48850

Banning Pass Area

CurrentNon-attainment (area is part of SE Desert Modified AQMA Area)Severe 17Unclassifiable/Attainment (part of SE Desert Air Basin, Riverside County, AQMA portion)N/ANon-attainment (part of Riverside County, Coachella Valley planning area)SeriousCannot be classified or better than national standards (part of Riverside County, non-AQMA portion)Cannot be classified (part of SE Desert Air Basin, excluding Imperial County).
ProposedNon-attainment (area becomes part of South Coast Air Basin)ExtremeNon-attainment (area becomes part of South Coast Air Basin)SeriousNon-attainment (area becomes part of South Coast Air Basin)SeriousCannot be classified or better than national standards (area becomes part of South Coast Air Basin)Cannot be classified (area becomes part of South Coast Air Basin).

We believe that Banning is more similar to the South Coast than the Coachella area, and that it would support efficient planning and control to move the federal boundary of the South Coast Air Basin eastward to encompass the Banning Pass area.

C. Revision to the Southeast Desert Ozone Nonattainment Boundary to Align It's Eastern Border With the Coachella Valley PM-10 Nonattainment Boundary

At present, the boundary of the Coachella Valley portion of the Southeast Desert ozone nonattainment area is different from the boundary of the Coachella Valley nonattainment area for PM-10. The existing ozone nonattainment area boundary differs from the Riverside portion of the Southeast Desert Air Basin boundary by: (1) Excluding a sparsely populated, 550 square mile portion of the Coachella Valley area, and (2) including a tiny portion of the Southeast Desert Air Basin. The State has proposed to align the Coachella Valley nonattainment area boundaries by using for all pollutants the boundary of the Coachella Valley nonattainment area for PM-10. This boundary tracks the mountain ridge line that separates the air basins and thus reflects air quality considerations. The change will simplify and make more consistent the planning activities for ozone and PM-10, and will reconcile boundaries for Federal and State planning purposes. As a result of the change, a sparsely-populated mountainous area above the Coachella Valley would shift from an ozone attainment area to a nonattainment area, with a severe-17 classification.

We agree with the State's argument that it is appropriate to align the federal boundaries of the Coachella Valley portion of the Southeast Desert Air Basin ozone nonattainment area to match the Coachella Valley PM-10 nonattainment area.

D. Typographical Correction to the Boundaries of the South Coast Air Basin for Carbon Monoxide

The CO boundaries of the South Coast Air Basin in 40 CFR 81.305 are incorrect because they mistakenly incorporate the following phrase: “and that portion of San Bernardino County which lies south and west of a line described as follows: 3. latitude 35 degrees, 10 minutes north and longitude 115 degrees, 45 minutes west.” Neither EPA nor CARB intended the South Coast CO nonattainment area to include this portion of San Bernardino County, which was inadvertently incorporated in the designations promulgated on November 6, 1991 (56 FR 56724). California requests that we correct this typographical mistake in the original designation by deleting the portion of the boundary description quoted above. Correction of this error will result in the CO boundaries conforming to the 1-hour ozone boundaries for the South Coast Air Basin. We agree that this correction is appropriate.

III. Summary of Proposed Action and Request for Comment

EPA is proposing to take the following actions:

(1) Approve the State's request to revise the boundary of the South Coast Air Basin to incorporate the Banning Pass;

(2) Approve the State's request to amend the 1-hour ozone boundary of the Coachella Valley area (Riverside County portion of the Southeast Desert Air Basin to correspond to the PM-10 boundary; and

(3) Approve the State's request to make a typographical correction to the boundary of the South Coast Air Basin with respect to CO.

Because EPA believes the proposed boundary revisions, reorganizations, and corrections are consistent with relevant requirements, we are proposing to fully approve them under CAA section 107(d)(3)(D). We will accept comments from the public on this proposal for the next 30 days. Unless we receive convincing new information during the comment period, we intend to publish a final approval of the designation changes.

IV. Administrative Requirements

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this proposed action is not a “significant regulatory action” and therefore is not subject to review by the Office of Management and Budget. For this reason, this action is also not subject to Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355, May 22, 2001). This proposed action merely proposes to approve state law as meeting Federal requirements and imposes no additional requirements beyond those imposed by state law. Accordingly, the Administrator certifies that this proposed rule will not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because this rule proposes to approve pre-existing requirements under state law and does not impose any additional enforceable duty beyond that required by state law, it does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).

This proposed rule also does not have tribal implications because it will not Start Printed Page 48851have a substantial direct effect on one or more Indian tribes, on the relationship between the Federal Government and Indian tribes, or on the distribution of power and responsibilities between the Federal Government and Indian tribes, as specified by Executive Order 13175 (65 FR 67249, November 9, 2000). This action also does not have Federalism implications because it does not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999). This action merely proposes to approve a state rule implementing a Federal standard, and does not alter the relationship or the distribution of power and responsibilities established in the Clean Air Act. This proposed rule also is not subject to Executive Order 13045 “Protection of Children from Environmental Health Risks and Safety Risks” (62 FR 19885, April 23, 1997), because it is not economically significant.

In reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. In this context, in the absence of a prior existing requirement for the State to use voluntary consensus standards (VCS), EPA has no authority to disapprove a SIP submission for failure to use VCS. It would thus be inconsistent with applicable law for EPA, when it reviews a SIP submission, to use VCS in place of a SIP submission that otherwise satisfies the provisions of the Clean Air Act. Thus, the requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply. This proposed rule does not impose an information collection burden under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).

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List of Subjects in 40 CFR Part 81

  • Environmental protection
  • Air pollution control
  • National parks
  • Wilderness areas
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Dated: August 6, 2003.

Deborah Jordan,

Acting Regional Administrator, Region IX.

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1.  Boundary changes are an inherent part of a designation or redesignation of an area under the CAA. See CAA section 107(d)(1)(B)(ii).

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2.  The Los Angeles-South Coast Air Basin Area includes all of Orange County and the more populated portions of Los Angeles, San Bernardino, and Riverside Counties. The Southeast Desert Air Basin includes portions of Los Angeles, San Bernardino, and Riverside Counties. For a description of the current boundaries of the basins and subareas, see 40 CFR 81.305.

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3.  The Coachella Valley area is part of the Southeast Desert nonattainment area for ozone and is its own PM-10 nonattainment area.

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4.  CAA sections 181(a)(1) and (2) establish an ozone classification scheme based on 1-hour ozone design values, and set attainment deadlines for each classification. CAA section 182 then provides progressively more stringent requirements for the State Implementation Plans (SIPs) depending upon an area's classification. The 1-hour ozone classifications are marginal, moderate, serious, severe, and extreme, and the severe classification is divided into those areas with attainment deadlines 15 years after enactment of the 1990 CAA Amendments and those areas with deadlines 17 years after enactment. Similarly, the CAA sets moderate and serious classifications for CO (in section 186(a)(1)) and for PM-10 (in sections 188(a) and (b)).

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[FR Doc. 03-20894 Filed 8-14-03; 8:45 am]