The Iowa Department of Natural Resources committed to comply with the PM10 regulations as set forth in 40 CFR part 51. In a letter to Morris Kay, EPA, dated October 28, 1988, Mr. Larry J. Wilson, Director, Iowa Department of Natural Resources, stated:
Three groups within the State of Iowa have been classified as Group II areas for fine particulate (PM-10) State Implementation Plan (SIP) development purposes. This includes portions of the cities of Des Moines, Mason City, and Cedar Rapids. The specific boundaries of these areas were identified in a letter of October 13, 1987, from Peter R. Hamlin to Carl Walter. The remainder of the State was classified as Group III.
In accordance with the SIP development procedures identified in the preamble of the PM-10 regulations for Implementing Revised Particulate Matter Standards, promulgated July 1, 1987, the State of Iowa commits to perform the following activities in these three Group II areas of the state:
(a) Gather ambient PM-10 data, to an extent consistent with minimum EPA requirements (note the network description contained in a letter of January 26, 1988, from Peter R. Hamlin to John Helvig).
(b) Analyze and verify the ambient PM-10 data and report exceedances of the 24-hour PM-10 National Ambient Air Quality Standards (NAAQS) to the Regional Office within 60 days of each exceedance.
(c) Immediately notify the Regional Office:
(1) Upon the availability of an appropriate number of verifiable 24-hour NAAQS exceedances to indicate a violation (see Section 2.0 of the PM-10 SIP development guideline) or
(2) when an annual arithmetic mean (AAM) above the annual PM-10 NAAQS becomes available.
(d) Within thirty (30) days of any notification of the Regional Office pursuant to (c) above (or upon collection of thirty-six (36) months of PM-10 ambient air quality data acceptable to EPA, whichever comes first) determine whether the measures in the existing SIP will assure timely attainment and maintenance of the primary PM-10 NAAQS and immediately notify the Regional Office of the results of this determination.
(e) Within six (6) months of any notification pursuant to (d) above, adopt and submit to EPA a PM-10 control strategy that assures attainment as expeditiously as practicable but not later than three (3) years from approval of the Committal SIP.
Because of the uncertainty about when the determination can be made pursuant to (d) above, it is difficult to determine if that control strategy could provide for the attainment of the PM-10 NAAQS within three years from the date EPA approves this Committal SIP. Therefore, I reserve the right to request a two-year extension of the attainment date as provided in Section 110(e) of the Clean Air Act, if and when the State of Iowa submits a SIP revision for any of these areas of the state.
The State of Iowa also commits to develop a PM-10 emission inventory for the areas submitted as part of any PM-10 SIP pursuant to items (c), (d), and (e) above. If the PM-10 NAAQS are not violated, the State of Iowa will proceed with this inventory for the three Group II areas in accordance with the following schedule:
October 1, 1988 - Request special assistance funds from EPA to perform the inventory.
October 1, 1989 - Initiate inventory.
August 1, 1990 - Complete inventory.
October 31, 1990 * - Submit inventory as part of a determination of adequacy that the current SIP will attain and maintain the PM-10 NAAQS.
[54 FR 33539, Aug. 15, 1989]