Technology Transfer Network / NAAQS
Ozone Implementation
Prior Designation Retained by Operation of Law in 1991 But Without Measured
Violation Based on 1987-89 Data CMSA/MSA/Non-MSA
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Section 185A Ozone Nonattainment Areas Which Were Revoked Without Maintenance Plans
As of July 20, 2000
Located
Design Average No. in a
Value Expected Counties Population EPA CMSA
Areas Listed Alphabetically (ppm) Exceedance NAA (1,000) Region State MSA
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Chico, CA 0.100 0.0 1 182 9 CA msa
Denver-Boulder, CO 0.122 0.7 6 1709 8 CO cmsa
Flint, MI 0.124 1.0 1 430 5 MI msa
Yuba City, CA 0.120 1.0 2 102 9 CA msa
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4 Total Areas 10 2,423
Section 185A areas had 3 complete years of data. "Section 185A" was previously called "Transitional". Totals were
adjusted to account for multiple areas in a single county.