DC Circuit Strikes Down MACT Start Up, Shut Down and Malfunction Exemption

Air pollution control equipment is generally meant to run at a steady level. When operating conditions fluctuate, due to start up, shutdown, or malfunction (SSM), the pollution control equipment may not operate optimally, and permit limits may be exceeded. EPA and the WV DEP have traditionally acknowledged that situation, and excused what would otherwise be permit violations during SSM events as long as the source was making an effort to reduce emissions as much as reasonably possible. However, a DC Circuit decision last month struck down the SSM exemption as it applies to hazardous air pollutants (HAPs), found in 40 CFR Part 63. The Court declared that the legislative history and the language of the Clean Air Act required it to reject any exceedance of limits set for HAPs. The SSM exemption for other types of pollutants was not affected. A more involved explanation of the decision can be found here.

HAPs are subject to stringent limits, based on the Maximum Achievable Control Technology (MACT). Limits on HAPs are often referred to as MACT limits.

West Virginia has adopted 40 CFR Part 63 by reference in 45 CSR 34, meaning that the federal rules for HAPs apply as if they were written in state regulations. This manner of adopting regulations helps to standardize state and federal regulations, and it relieves those of us who have to check for differences between state and federal regulations from having to compare the state and federal rules word for word, looking for differences. In adoption by reference, only the differences between the state and federal rules are noted, making it easy to see where the rules diverge.

When the federal rule changes, the state has to adopt the change before it can become effective in WV. That can pose some problems, because rule making is a lengthy process in WV, and sometimes federal rule changes become effective before the state can change its rule. When the change is done by a court, as occurred here, the problem is compounded. However, anyone with a MACT standard should be leery of relying on SSM as a justification for violating a HAP limit after the DC Court's decision.