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Proposed Rule

Clean Air Act Determination of Attainment for PM10

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AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing to make determinations of attainment for the particulate matter with an aerodynamic diameter less than or equal to a nominal 10 microns (PM10) National Ambient Air Quality Standards (NAAQS) for the Whitefish, Montana, Thompson Falls, Montana and Steamboat Springs, Colorado moderate PM10 nonattainment areas. The Whitefish, Montana nonattainment area was required by the Clean Air Act Amendments (CAAA) of 1990 to attain the PM10 NAAQS by December 31, 1999. This proposed determination is based on complete, quality assured ambient air quality monitoring data for the years 1997, 1998, and 1999. The Thompson Falls, Montana and Steamboat Springs, Colorado nonattainment areas were required by the Clean Air Act Amendments (CAAA) of 1990 to attain the PM10 NAAQS as of December 31, 2000. These proposed determinations are based on complete, quality assured ambient air quality monitoring data for the years 1998, 1999, and 2000.

DATES:

Written comments must be received on or before September 7, 2001.

ADDRESSES:

Written comments may be mailed to Richard R. Long, Director, Air and Radiation Program, Mailcode 8P-AR, Environmental Protection Agency (EPA), Region VIII, 999 18th Street, Suite 300, Denver, Colorado, 80202. Copies of the documents relevant to this action are available for public inspection during normal business hours at the Air and Radiation Program, Environmental Protection Agency, Region VIII, 999 18th Street, Suite 300, Denver, Colorado, 80202 and copies of the Incorporation by Reference material are available at the Air and Radiation Docket and Information Center, Environmental Protection Agency, 401 M Street, SW., Washington, DC 20460.

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FOR FURTHER INFORMATION CONTACT:

Cindy Rosenberg, EPA, Region VIII, (303) 312-6436.

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SUPPLEMENTARY INFORMATION:

Throughout this document, wherever “we”, “us”, or “our” are used, we mean the Environmental Protection Agency (EPA).

Table of Contents

I. Background

A. Designation and Classification of PM10 Nonattainment Areas.

B. How Does EPA Make Attainment Determinations?

II. EPA's Proposed Action

III. Basis for EPA's Proposed Action

A. Whitefish, Montana

1. Determination that the Whitefish PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 1999.

B. Thompson Falls, Montana

1. Determination that the Thompson Falls PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 2000.

C. Steamboat Springs, Colorado

1. Determination that the Steamboat Springs PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 2000.

IV. Administrative Requirements

I. Background

A. Designation and Classification of PM10 Nonattainment Areas

The Whitefish and Thompson Falls areas were designated nonattainment for PM10 and classified as moderate under section 107(d)(3) of the Clean Air Act, on October 19, 1993 and December 21, 1993 respectively.[1] See 58 FR 36907 (July 9, 1993), 58 FR 53886 (October 19, 1993) and 40 CFR 81.327 (Flathead County (part)) in regards to Whitefish. See 57 FR 43846 (September 22, 1992), 58 FR 67334 (December 21, 1993) and 40 CFR 81.306 (Sanders County (part)) in regards to Thompson Falls. The Whitefish designation became effective on November 18, 1993 and the Thompson Falls designation became effective on January 20, 1994. The Steamboat Springs, Colorado area was designated nonattainment for PM10 and classified as moderate under section 107(d)(3) of the CAA, on December 21, 1993. See 57 FR 43846 (September 22, 1992), 58 FR 67334 (December 21, 1993) and 40 CFR 81.306 (Routt County (part)). The Steamboat Springs Start Printed Page 41487designation became effective on January 20, 1994. The air quality planning requirements for moderate PM10 nonattainment areas are set out in Subparts 1 and 4 of Title I of the Act.[2]

B. How Does EPA Make Attainment Determinations?

All PM10 nonattainment areas are initially classified “'moderate”' by operation of law when they are designated nonattainment. See section 188(a). Pursuant to sections 179(c) and 188(b)(2) of the Act, we have the responsibility of determining within six months of the applicable attainment date whether, based on air quality data, PM10 nonattainment areas attained the NAAQS by that date. Determinations under section 179(c)(1) of the Act are to be based upon an area's “air quality as of the attainment date.” Section 188(b)(2) is consistent with this requirement.

Generally, we will determine whether an area's air quality is meeting the PM10 NAAQS for purposes of section 179(c)(1) and 188(b)(2) based upon data gathered at established state and local air monitoring stations (SLAMS) and national air monitoring sites (NAMS) in the nonattainment area and entered into the Aerometric Information Retrieval System (AIRS). Data entered into the AIRS has been determined to meet federal monitoring requirements (see 40 CFR 50.6, 40 CFR part 50 appendix J, 40 CFR part 53, 40 CFR part 58 appendix A & B) and may be used to determine the attainment status of areas. We will also consider air quality data from other air monitoring stations in the nonattainment area provided that the stations meet the federal monitoring requirements for SLAMS. We review all data to determine the area's air quality status in accordance with our guidance at 40 CFR part 50, appendix K.

As described in 40 CFR part 50 and appendix K, attainment of the annual PM10 standard is achieved when the annual arithmetic mean PM10 concentration over a three year period (for example, 1998, 1999, 2000 for areas with a December 31, 2000 attainment date) is equal to or less than 50 micrograms per cubic meter (μg/m3). Attainment of the 24-hour standard is determined by calculating the expected number of days in a year with PM 10 concentrations greater than 150 μg/m3. The 24-hour standard is attained when the expected number of days with levels above 150 μg/m3 (averaged over a three year period) is less than or equal to one. Three consecutive years of air quality data is generally necessary to show attainment of the 24-hour and annual standard for PM10. Appendix K, of 40 CFR part 50, addresses procedures for calculating expected annual averages and expected annual exceedances that are used for PM10 attainment determinations. The expected annual average is calculated as the average of the three annual means. The expected number of annual exceedances is calculated as the average of the number of exceedances for three years; if data in a given year are incomplete, but meet the minimum requirements specified in appendix K, the annual exceedance rate is estimated from the observed exceedance rate. Prior to 1998, the required sampling frequency for PM10 was one 24-hour sample every six days, every two days, or every day, depending on the probability of nonattainment of the PM10 standards. According to a revision to 40 CFR 58.13 that was effective starting in 1998, the required sampling frequency is a minimum of one 24-hour sample taken every third day, except during periods or seasons exempted by the Regional Administrator. We recognize that data from some scheduled sampling days may be missing for any number of reasons, (e.g. damaged filters, miscalibrated equipment, or other equipment failure) therefore, exceptions have been made to the required sampling frequencies. Appendix K specifies a minimum 75% data capture rate of required PM10 samples, but states that: “Data not meeting these criteria may also suffice to show attainment, however, such exceptions will have to be approved by the Regional Administrator in accordance with established guidelines.” See 40 CFR part 50 and appendix K. Our April 1987 “Guideline on Exceptions to Data Requirements for Determining Attainment of Particulate Matter Standards” provides eligibility requirements and guidance on exceptions to the data requirements, but was not intended to list all possible situations in which data may be acceptable. The guidance states that other procedures besides those described may be used if approved by the Regional Administrator.

II. EPA's Proposed Action

Based on quality-assured data meeting the requirements of 40 CFR 50, appendix K, we are proposing to find that Whitefish, Montana attained the PM10 NAAQS as of December 31, 1999 and that Thompson Falls, Montana and Steamboat Springs, Colorado attained the PM10 NAAQS as of December 31, 2000. This proposed action to determine attainment for Whitefish, Montana is based on monitored air quality data for the national ambient air quality standard (NAAQS) for PM10 from the years 1997-99, and the actions for Thompson Falls, Montana and Steamboat Springs, Colorado are based on data from the years 1998-2000. If we finalize this proposal, consistent with CAA section 188, the areas will remain moderate PM10 nonattainment areas and avoid the additional planning requirements that apply to serious PM10 nonattainment areas.

This action should not be confused with a redesignation to attainment under CAA section 107(d) because neither Montana nor Colorado have submitted a maintenance plan as required under section 175(A) of the CAA or met the other CAA requirements for redesignation. The designation status in 40 CFR part 81 will remain moderate nonattainment for all three areas until such time as Montana and Colorado meet the CAA requirements for redesignations to attainment.

We are soliciting public comments on the issues discussed in this document or on other relevant matters. These comments will be considered before taking final action. Interested parties may participate in the Federal rulemaking procedure by submitting written comments to the EPA Regional office listed in the ADDRESSES section of this document.

III. Basis for EPA's Proposed Action

A. Whitefish, Montana

1. Determination that the Whitefish PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 1999.

Whether an area has attained the PM10 NAAQS is based exclusively upon measured air quality levels over the most recent and complete three calendar year period. See 40 CFR part 50 and 40 CFR part 50, appendix K. Since the attainment date for Whitefish was December 31, 1999, the three year period covers calendar years 1997, 1998, and 1999. Samples were collected on an every day schedule for Whitefish during this time period.

The PM10 concentrations reported at the monitoring site showed one measured exceedance of the 24-hour PM10 NAAQS in 1997 with a value of 178 μg/m3; the expected exceedances for this year also calculated to 1. For 1998 and 1999, the number of exceedances and expected exceedances were 0.0. Start Printed Page 41488Thus, the three-year average was less than 1.0, which indicates that Whitefish attained the 24-hour PM10 NAAQS as of December 31, 1999. The second highest value recorded between 1997 and 1999 at the Whitefish monitoring site was 138 μg/m3 which is below the standard of 150 μg/m3.

Review of the annual standard for calendar years 1997, 1998 and 1999 reveals that Whitefish also attained the annual PM10 NAAQS by December 31, 1999. There was no violation of the annual standard for the three year period from 1997 through 1999. The expected annual average value for the three year period was 29 μg/m3, which is below the standard of 50 μg/m3.

B. Thompson Falls

1. Determination that the Thompson Falls PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 2000.

Since the attainment date for Thompson Falls was December 31, 2000, the three year period covers calendar years 1998, 1999, and 2000. The PM10 concentrations reported at the two monitoring sites showed no measured exceedances of the 24-hour PM10 NAAQS between 1998 and 2000. Review of the annual standard for calendar years 1998, 1999 and 2000 reveals that Thompson Falls also attained the annual PM10 NAAQS by December 31, 2000. No monitoring sites showed a violation of the annual standard in the three year period from 1998 through 2000 and the expected annual average value for the three year period was 26 μg/m3, which is below the standard of 50 μg/m3. The sampling frequency at the Thompson Falls monitoring site during the first and fourth quarters of 1998 and 1999 was every two days and every sixth day for the second and third quarters. During 2000, the sampling frequency was every two days for the first quarter, every sixth day for second and third quarters and every third day for the fourth quarter.

As described above, the 1987 Guideline provides eligibility requirements and example situations in which data may be substituted. For Thompson Falls, there were two quarters during this three year attainment period (1998-2000), which had less than 75% data capture, but greater than 50% data capture and thus qualified for data substitution under our guidelines. The first quarter of 1999 had 12 values substituted, and used an 89 μg/m3 value from February 25, 1997 for substitution, bringing the quarterly average to 39.3 μg/m3, and the 1999 annual average to 35.1 μg/m3. The third quarter of 2000 had 4 values substituted, and used a 75 μg/m3 value from August 10, 2000 as the substitution value, bringing the quarterly average to 40.7 μg/m3, and the 2000 annual average to 20.5 μg/m3.

In 1999, the data recovery for Thompson Falls was incomplete due to extenuating circumstances at the monitoring site. The Courthouse on which the monitoring site had been located was being re-roofed and therefore, MDEQ was forced to find a new site on short notice, without enough time to set up a new monitoring site before the existing site was shut down. This forced MDEQ to miss all the monitoring days for the entire 3rd quarter of 1999. A new monitoring site was set up on the grounds of the local high school for the fourth quarter of 1999. The Region used 40 CFR part 50 appendix K and our April 1987 “Guideline on Exceptions to Data Requirements for Determining Attainment of Particulate Matter Standards” to address the missing data from 1999. The Region decided to substitute third quarter data from 1998 for 1999 because we believe that it is representative of what third quarter 1999 data would have looked like had the monitoring site continued to operate. We believe this is an acceptable method because the exceedances that Thompson Falls experienced in the early 1990's were during winter months, not during the third quarter of the year. In addition, the particulate problem in Thompson Falls is related to road dust and that problem has been resolved since street sweeping measures were adopted by Montana and implemented in 1998. Therefore, we don't expect that there would have been any recorded exceedances during the third quarter of 1999 had the monitor been operating.

Since MDEQ was forced to change monitoring sites in the middle of the three year period necessary for Thompson Falls to show attainment by the area's attainment date, we don't have complete data at any one monitoring site. However, we believe that combining the data from the two separate monitoring sites is acceptable in this situation. We also believe that the location of the replacement monitoring site within the extremely small town of Thompson Falls provides adequate characterization of the community's air. We believe that Thompson Falls' data meets our Guideline and rule requirements. Therefore, with the preceding actions concluded, we believe that the data indicates that Thompson Falls attained the 24-hour and annual PM10 NAAQS as of December 31, 2000.

C. Steamboat Springs

1. Determination That the Steamboat Springs PM10 Nonattainment Area Attained the PM10 NAAQS as of December 31, 2000.

Since the attainment date for Steamboat Springs was December 31, 2000, the three year period covers calendar years 1998, 1999, and 2000. Steamboat Springs was operating on an every day sampling frequency during this time period. The PM10 concentrations reported at the monitoring site showed no measured exceedances of the 24-hour PM10 NAAQS between 1998 and 2000, which indicates Steamboat Springs attained the 24-hour PM10 NAAQS as of December 31, 2000. The highest monitored 24-hour value between 1998 and 2000 was 148 μg/m3. Although this wasn't an exceedance of the NAAQS, we agreed with Colorado that this value should be excluded as a high wind event under our May 30, 1996 “Areas Affected by PM-10 Natural Events,” policy. This data was flagged as a natural event in our Aerometric Information Retrieval System (AIRS) and Colorado submitted the proper documentation package to us certifying that this monitored value was due to unusually high winds in the area. Because of this, the highest applicable monitored 24-hour value during the three year period was 121 μg/m3 which is below the standard of 150 μg/m3.

Review of the annual standard for calendar years 1998, 1999 and 2000 reveals that Steamboat Springs also attained the annual PM10 NAAQS by December 31, 2000. Data collected at the monitoring site showed no violations of the annual standard in the three year period from 1998 through 2000. The expected annual average value for the three year period was 25 μg/m3, which is below the standard of 50 μg/m3.

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. This rule is not subject to Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355 (May 22, 2001)) because it is not a significant regulatory action under Executive Order 12866. This proposed action merely determines that certain States have met federal requirements and imposes no requirements. Accordingly, the Administrator certifies that this proposed rule will not have a significant Start Printed Page 41489economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because this proposed rule would not impose any enforceable duty, it does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Public Law 104-4). For the same reason, this proposed rule also does not significantly or uniquely affect the communities of tribal governments, as specified by Executive Order 13084 (63 FR 27655, May 10, 1998). This proposed rule will 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), because it merely determines that several nonattainment areas have met federal requirements, 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 (62 FR 19885, April 23, 1997), because it is not economically significant.

As required by section 3 of Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing this proposed rule, EPA has taken the necessary steps to eliminate drafting errors and ambiguity, minimize potential litigation, and provide a clear legal standard for affected conduct. EPA has complied with Executive Order 12630 (53 FR 8859, March 15, 1988) by examining the takings implications of the rule in accordance with the “Attorney General's Supplemental Guidelines for the Evaluation of Risk and Avoidance of Unanticipated Takings” issued under the executive order. This 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.).

Start Signature

Dated: July 30, 2001.

Jack W. McGraw,

Acting Regional Administrator, Region VIII.

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Footnotes

2.  The 1990 Amendments to the Clean Air Act made significant changes to the Act. See Public Law No. 101-549, 104 Stat. 2399. References herein are to the Clean Air Act, as amended (“the Act”). The Clean Air Act is codified, as amended, in the U.S. Code at 42 U.S.C. Sections 7401, et seq.

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2.  Subpart 1 applies to nonattainment areas generally and Subpart 4 applies to PM10 nonattainment areas. At times, Subpart 1 and Subpart 4 overlap or conflict. We have attempted to clarify the relationship among these provision in the “General Preamble for the Implementation of Title I of the Clean Air Act Amemdments of 1990.” (See 57 FR 13498, April 16, 1992.

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[FR Doc. 01-19877 Filed 8-7-01; 8:45 am]

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