About two weeks ago I wrote about EPA's decision to promulgate mercury rules similar to those in the Clear Skies initiative despite the failure of that measure in committee. Apparently a lot of people agreed, since nine states are now suing EPA over the new rules.

I said as much as I’m going to say about why the mercury rules are nowhere near strict enough and why the mercury trading program will fail, but I do want to draw attention to one part of the L.A. Times article linked above:

The lawsuit alleges that the EPA broke the law by enacting a rule that exempts power plant emissions of mercury from a Clean Air Act requirement that the "maximum available control technology" be used to reduce toxic air pollution.

The Clean Air Act does require emissions standards for the almost 200 listed toxic air pollutants to be based on the Maximum Available Control Technology (MACT). In layperson’s terms means that the standards must be based on the best controlled sources using advanced emissions control technology. I suspect that the EPA will argue that the recent standards fit this definition, which may appear to be a tenuous claim, though it’s worth re-reading the definition of MACT standards again and noting that they are neither absolute nor clear as day. It may prove difficult to show beyond a reasonable doubt that the current standards do not meet MACT.

In truth, the only piece of information about this case that seems to favor either side is the fact that it was filed in the D.C. Circuit, which is historically environmentally friendly.