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Start Over You searched for: Year 1979 Remove constraint Year: 1979 Subject Air quality management Remove constraint Subject: Air quality management Theme Boundaries Remove constraint Theme: Boundaries

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1979. United States. Bureau of Transportation Statistics and Stackhouse, Cecil. This polygon shapefile depicts nonattainment and maintenance areas for the United States and its Territories for the enforcement of the ozone (O3) ... United States. Bureau of Transportation Statistics.