Proposed Update to NOx SIP Call Regulations
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Rule Summary
Update to NOX SIP Call Regulations: Addition of Monitoring Flexibility and General Streamlining of Provisions
EPA is proposing to amend the NOX SIP Call regulations. Under the existing regulations, affected states must include provisions in their state implementation plans (SIPs) requiring certain covered facilities to monitor summertime NOX emissions according to 40 CFR part 75, which generally entails the use of continuous emission monitoring systems (CEMS). Most of these facilities – primarily power plants – must also perform part 75 monitoring under other programs such as the Acid Rain Program and the Cross-State Air Pollution Rule trading programs, but some of the sources – primarily industrial facilities – must perform part 75 monitoring only because of the SIP provisions required by the NOX SIP Call regulations. Under current circumstances, other forms of monitoring requirements for these remaining sources could provide adequate assurance that the NOX SIP Call’s required emissions reductions will continue to be achieved. Accordingly, this proposed rule would amend the NOX SIP Call regulations to allow states to revise their SIPs to include alternate, potentially lower-cost monitoring requirements in their SIPs for NOX SIP Call purposes. The increased flexibility provided by the proposed rule would lead to potentially lower monitoring costs for some sources in states that submit approvable SIP revisions.