(Dallas) ----After its most severe "ozone season" in five years, Dallas-Ft. Worth has displaced Houston as the Texas metropolitan area with the worst air quality problem.   

Final numbers from 2011's seven-month smog cycle, which ended Monday, show DFW with higher ozone levels and a larger percentage of monitors in exceedance of the old 1997 federal ozone standard of 85 ppb versus the Bayou City.  

Jim Schermbeck, Director of Downwinders at Risk, a DFW-based citizens clean air group, said it represented the latest failure of the state to take the region's chronic air pollution problem seriously.

"Austin has showed a deep and abiding apathy toward Dallas-Ft.Worth's smog problem. I wish I thought this news would change that, but I don't think it will." He noted that despite a significant rise in ozone pollution in 2011, the state is still going forward with a proposed clean air plan for DFW that relies exclusively on the hope that residents buy enough new cars in the next six months to bring smog down to the unprecedented levels necessary to meet federal law. "Does that sound like a serious effort to you?"   

Officially, DFW now has a three-year running "Design Value" of 90.6 ppb of ozone at its Keller monitor compared to the 89.6 ppb at Houston's Manvel-Croix Park monitor. Design Values are the benchmarks used by the state and EPA to determine compliance with the Clean Air Act. They're based on annual 4th highest readings recorded at ozone monitors operated by the Texas Commission on Environmental Quality. 

DFW also saw 7 out of 20 monitors, or 35%, record "exceedances" that violate the 1997 8-hour average standard of 85 ppb while Houston saw 11 out of its 46 monitors, or 23% do the same.  

DFW and Houston shared an average of 91 ppb for the highest seasonal readings among all of their monitors, but DFW had a higher average of those exceeding the 1997 standard, 91.5 ppb, versus Houston with 88.1.  Houston saw 21 days over the 1987 85 ppb standard; DFW 20.   

What's remarkable to many long-time observers is that, compared to DFW, Houston's non-attainment area for smog has more than twice as many monitors spread over a much larger geographical area, and hosts a fourth of the nation's petro-chemical industry, and yet "white collar" DFW was still able to record ozone levels worse than it.      

"There's a myth that the Perry administration is fond of spinning that air quality in DFW is getting better. It's not," said Schermbeck. "Despite three clean-air plans over the last 15 years, we've never reached the 85 ppb standard in DFW. We stalled out. We never made the kind of progress that was predicted by the state, or needed by residents. And this year we're going back to levels we haven't seen since 2006 - before the last clean air plan took effect. "  

Many officials may try to link DFW's 2011 higher smog levels to the record number of 100 degree + temperatures the region saw this summer, but there's evidence indicting that extremely hot weather actually discourages ozone formation because it reduces mixing in the atmosphere. Some of the worst ozone episodes of the entire season took place the last week of September, when temperatures were between 90 and 100 degrees.   

For most of the last three decades, Houston smog has obtained legendary status, on par with that of Los Angeles. But something has happened over the last several years. DFW has begun to show a more stubborn resistance to new strategies and controls to reduce its own ozone pollution, while Houston air quality has been improving.   

Schermbeck and other environmentalists think there's a number of factors contributing to the inability of DFW to reign-in its chronic smog problem. One is what Schermbeck calls the state's refusal to cut smog-forming pollution from Barnett Shale gas drilling. Despite estimating that gas industry sources now emit more Volatile Organic Compounds than all the cars and trucks in DFW, the Texas Commission on Environmental Quality isn't targeting these emissions in its proposed clean air plan for the region.     

Five of DFW's seven monitors exceeding the 85 ppb standard in 2011 were located in the Barnett Shale, including the Keller site which had the highest ozone levels in DFW as well as the most smog exceedances.    

Schermbeck also cited still-unresolved contributors such as the complex of three Midlothian cement plants that operate without the best anti-smog controls and coal-fired utility plants still similarly not updated.    

Numbers from this summer also give an indication how hard it'll be for both regions to comply with the newly-approved federal eight-hour ozone standard of 75 ppb. Houston had 43 days when that standard was violated, while DFW had 38. Applying this new standard to DFW in 2011 would have meant a jump in individual monitor "exceedences" of the federal clean air standard, from 82 separate monitor readings at or above the 85ppb standard, to 236 monitor readings higher than the new standard this year.

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