The state of Nebraska committed to conform to the PM10 regulations as set forth in 40 CFR part 51. In a letter to Morris Kay, EPA, dated February 5, 1988, Mr. Dennis Grams, Director, Nebraska Department of Environmental Control, stated:

(a) An area in the City of Omaha and the area in and around the Village of Weeping Water have been classified as Group II areas for the purpose of PM10 State Implementation Plan (SIP) development. The specific boundaries of these areas are identified in our letter of October 6, 1987, to Carl Walter. In accordance with the requirements for PM10 SIP development, the State of Nebraska commits to perform the following PM10 monitoring and SIP development activities for these Group II areas:

(1) Gather ambient PM10 data, at least to the extent consistent with minimum EPA requirements and guidance.

(2) Analyze and verify the ambient PM10 data and report 24-hour exceedances of the National Ambient Air Quality Standard for PM10 to the Regional Office within 45 days of each exceedance.

(3) When an appropriate number of verifiable exceedances of the 24-hour standard occur, calculated according to section 2.0 of the PM10 SIP Development Guideline, or when an exceedance of the annual PM10 standard occurs, acknowledge that a nonattainment problem exists and immediately notify the Regional Office.

(4) Within 30 days of the notification referred to in paragraph (a)(3) of this section, or within 37 months of promulgation of the PM10 standards, whichever comes first, determine whether measures in the existing SIP will assure timely attainment and maintenance of the PM10 standards and immediately notify the Regional Office.

(5) Within 6 months of the notification referred to in paragraph (a)(4) of this section, adopt and submit to EPA a PM10 control strategy that assures attainment as expeditiously as practicable but no later than 3 years from approval of the committal SIP.

An emission inventory will be compiled for the identified Group II areas. If either area is found to be violating the PM10 standards, the inventory will be completed as part of the PM10 SIP for that area on a schedule consistent with that outlined in paragraphs 3, 4, and 5. If the PM10 standards are not violated, the inventory will be completed not later than July 1, 1989, and submitted to EPA not later than August 31, 1990, as part of the determination of adequacy of the current SIP to attain and maintain the PM10 air quality standards.

(b) We request that the total suspended particulate nonattainment areas in Omaha and Weeping Water (all secondary nonattainment) and Louisville (Primary nonattainment) be redesignated to unclassifiable.