Air quality and the Eagle Ford: a Q&A with Peter Bella, AACOG natural resources director
Published: March 21, 2012
Where are we in terms of compliance with federal air quality standards?
Our 2011 design value, that's the past three years worth of data averaged together, is at 75 ppb (parts per billion). That's the three-year average we call our design value. At 76 ppb, we're over (the federally mandated level). So you can see we're right on that cusp.
When you look at the precursors, the ozone precursors in the San Antonio-New Braunfels Metropolitan Statistical Area, which is an eight-county region with Bexar at its core, you look at these [nitrogen oxides, or NOx] numbers and the breakdown shows that principally power generation and the cement industry are current and well documented sources. They're the chief contributors of NOx that we know of right now.
Do you expect to see the share of NOx from mining grow due to the Eagle Ford?
There are a couple pieces that make that a difficult question to answer. One is that if you look at the AACOG region, if you look at the counties that literally have common boundaries, the eight counties don't really include the Eagle Ford shale. There's only a few counties — Frio, Atascosa, parts of Karnes and Wilson — that are really players in the Eagle Ford shale.
Air quality, if we're going to manage air quality, if we're going to manage ozone in particular, we're going to have to talk about managing the sources of ozone precursors. But there's a whole big stew, a whole big controversy and conversation about where the sources come from. We know that pollution comes from across the country. What goes around comes around when we're talking about the atmosphere.
The requirements for management from the Clean Air Act traditionally go with the MSA. That's where the conversation starts. Control ozone precursors that occur in the MSA. And the big conversation is about how adequate is that as a concept. One of the issues in trying to control the precursors is the way the Clean Air Act is written. If you go into non-attainment, the MSA's where the control discussion starts. The idea is that you're supposed to regain attainment, have good air quality, by controlling what's inside that boundary. Well, transport happens. Transport comes from outside. And as the threshold for attainment lowers, and the standard becomes more stringent, the standard gets closer to what are called background levels — to what you'd get if you were just in a desert and there were not people, no cars, nothing. So the less difference there is between the standard and what your background levels are, the less control effectively you really have. If there is a 5 ppb difference between the standard and what your background levels are, the concept of controlling everything we have in our region in order to make a 5 ppb reduction, that's a very tall order, that's very difficult business. Because the influences as a whole that come from outside may be so great, there's that whole aspect of the difficulty of the tools given to a region when a region goes into non attainment.
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