INGAA recommends that the EPA does not adopt more stringent Ozone regulations.

INGAA recommends that the EPA retain the current 75 part per billion (ppb) ozone NAAQS rather than pursue a more stringent standard.

In addressing its concerns, INGAA raises the following specific issues: (1) ambient ozone levels are declining and likely will continue to decrease in the coming years; (2) there is significant uncertainty in both the health benefits and implementation costs (3) EPA’s analysis is based on the use of “unknown” controls; and (3) if the EPA chooses to adopt lower NAAQS, INGAA supports the proposed grandfathering provisions for Prevention of Significant Deterioration (PSD) permitting.