Join us to discuss the issue and provide input to IDEM on ways to reduce NOx in the region. The SIP is submitted to the EPA for approval. If the SIP is found deficient, the EPA may apply a federal implementation plan in its place. Even if a SIP is approved, the EPA may call for revisions as necessary if the SIP no longer complies with the law. In 1997, the EPA determined that the ozone standard was inadequate and set a more stringent standard.
Every state monitors ozone.
Northeastern states had high levels of ozone in summer and were in nonattainment. These states claimed their ozone problem was due in part to upwind states releasing ozone-forming pollutants that contributed significantly to ozone problems in downwind states. Therefore, the EPA ordered Indiana and 18 other eastern states to revise their SIPs to improve air quality within the state and reduce interstate transport of ozone.