Emissions Monitoring Provisions in State Implementation Plans Required Under the NOX

The Environmental Protection Agency (EPA) is proposing to update the regulations that were originally promulgated in 1998 to implement the NOX SIP Call. In place of the current requirement for states to include provisions in their state implementation plans (SIPs) under which certain emissions sources must monitor their mass emissions of nitrogen oxides (NOX) according to 40 CFR part 75, the proposed amendments would allow states to include alternate forms of monitoring requirements in their SIPs. The amendments would also rescind the findings of interstate pollution transport obligations with respect to the 1997 8-hour ozone national ambient air quality standards (NAAQS) under the NOX SIP Call that have been stayed by EPA since 2000. Other revisions would remove additional obsolete provisions and clarify the remaining regulations but would not substantively alter any current regulatory requirements.