In September 2024, EPA issued a
final rule finalizing requirements for sources that reclassify from major source status to area source status under the NESHAP program. These major sources emit or have the potential to emit (PTE) ten (10) tons per year (tpy) or more of a single HAP or 25 tpy of more of a combination of HAP. Area sources emit HAPs at levels below those thresholds.
The rule provides that sources accounting for not less than 90 per centum of the aggregate emissions of any of the seven (7) persistent and bioaccumulative hazardous air pollutants of the Clean Air Act, must continue to comply with major source standards even if otherwise reclassified as area sources. The 7 pollutants include:
- alkylated lead compounds,
- polycyclic organic matter (POM),
- mercury,
- hexachlorobenzene,
- polychlorinated biphenyls (PCB),
- 2,3,7,8-tetrachlorodibenzofurans (TCDF) and
- 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
As a result, reclassified sources will still be subject to maximum achievable control technology standards rather than less stringent standards applicable to area sources. EPA expects to maintain that at least 90% of the cumulative emissions of these pollutants will be subject to NESHAP regardless of future source reclassifications. Therefore, if already subject to list as of September 10, 2024, even if reclassify to area source, the units will continue to be subject after reclassification.
