Air Pollution Control Equipment Services, Emissions

Mathematical Properties of the Clean Air Act

Issue 11 and Volume 116.

By Robynn Andracsek, P.E., Burns & McDonnell and Contributing Editor

Politics are fickle. Regardless of which candidate won the 2012 presidential election (I’m writing this at the end of September, so I don’t know the winner yet.), there will be change in how electric generation emissions are regulated and how utility companies are treated by the EPA. However, not everything is subject to the whims of politics; some aspects of utility regulation are as fixed as mathematical laws.

The Interstate Uncertainty Principle – CAIR, CSAPR, CAIR again: The EPA (whether under a Republican or Democratic administration) can’t quite seem to get it right. Beginning with the NOx SIP call in 1998, EPA’s goal has been to regulate how pollution from one state affects ambient air compliance in downwind states. Both the Clean Air Interstate Rule (CAIR) and the Cross-State Air Pollution Rule (CSAPR) were loosely based on one of EPA’s few successes (the Acid Rain Program), but both failed court scrutiny. One flaw seems to be how to trade emissions between and within states, or if that is even allowed under the Clean Air Act. Another is how to assign upwind responsibility, both quantitatively and qualitatively. The legal issues have led the courts to send these “interstate” rules back to EPA for yet another rewrite. EPA’s appeal of the latest decision may reach the Supreme Court.

The Emission Rate/Permit Limit Paradox – In operating a coal-fired power plant, reality and flexibility are inversely proportional. The less margin between operational design and permit requirements, the more likely it is that the limit will be exceeded. Environmental groups want super low emission limits, but due to natural variability in power plant operations, these stringent limits are likely to be exceeded. Power plant operators want permit limits that provide adequate margin to accommodate the natural operational variations without resulting in exceedances.

The Mercury Minimization Malfunction – Mercury is very toxic, explicitly required by the Clean Air Act (CAA) to be regulated and released during coal combustion. CAMR, case-by-case MACT, MATS: Once again, EPA again can’t seem to get the citizen groups, the utilities and the courts to agree on what is both legal and protective of the air we breathe. The environmental groups screamed that CAMR was “too little, too late” and rejoiced when it was vacated in 2008. But, as it turned out, if CAMR had not been overturned, we would have reached 90 percent Hg control nationwide at least one year sooner than we will under MATS.

The PSD Netting Instability – Netting under the Prevention of Significant Deterioration program boils down to use it or lose it. For example, if a power plant is permitted for 1,000 tons of NOx per year but only emits an average of 400 tpy, the facility is penalized instead of rewarded. When the plant applies for a modification (maybe to improve efficiency or upgrade boiler tubes for reasons of safety) the boiler could “net out” of PSD, but only if the future potential doesn’t exceed the past emissions by more than minimal 40 tpy. The punishment is that the past emissions are based on the actual 400 tpy and not the permitted 1,000 tpy. The plant would have been better positioned for the modification if it had emitted an extra 600 tpy, although air quality would certainly not have been better protected. The PSD-savvy utility environmental manager will ask the production department to run a unit that is slated for a physical upgrade as hard as possible during the 24 months leading up to the outage in which the change is to be made. This lessens the danger of triggering PSD but is not good for the environment.

The New Source Review Amplification – The largest fines in the history of Clean Air Act enforcement have been in cases of NSR enforcement, when utilities have been caught in the trap of performing “routine” maintenance without a permit, even though these activities are explicitly exempt from PSD. The meaning of “routine,” which does not appear in the CAA, has been reinterpreted and applied retroactively to redefine what acts of maintenance are permissible. Going forth under PSD, it is better to ask for permission than to beg for forgiveness when you interpret what is or is not “routine.”

The Comprehension Fluctuation – The Clean Air Act is complicated, poorly written and rife with contradictions. The only certainty is that if a specific regulation doesn’t make sense, then you probably understand it correctly.

Hmmm, then again, maybe the only facet of air permitting regulation that is for certain is that air permit engineering consultants have excellent job security.