Congratulations! We Have DFW’s First Official Smog Violation of the Season

Summer's here and the time is right for…putting on those gas masks.

This last Saturday saw DFW's first official violation of the federal ozone, or smog, standard of 75 ppb in 2015.

That doesn't mean it was the first instance of an "exceedence" of the 75 ppb standard at an area air monitor. Oh no. That happened at three different monitors (Parker County, Eagle Mountain Lake, and Denton) way back on May 1st.

As some veterans of the Air Wars know, it takes four, (count 'em, four) "exceedences" of the standard at the same monitor before you can count it as a "violation" of the Clean Air Act. As noted, Denton already had one from the first day of May. Last week's run of bad air days on Thursday, Friday and Saturday (rare) gave it the three more it needed to add up to a real violation. Lucky Denton. Fracking returns, and it hosts the region's worst concentration of smog, all in the same week. Coincidence? We report, you decide.

Denton's fourth exceedence in 2015 means there's no chance of DFW air being declared safe and legal this year. That site also had official violations the last two years as well, and since the "attainment" of the standard is determined by a rolling three-year average of the fourth highest exceedence (got that? ) – we're still stuck in "non-attainment" status. But that's probably not going to be a surprise to most of you.

Right now the three-year average is 79.6, but it's still early in the season. If there are more "exceedences" at the Denton site above the 77 ppb one recorded Saturday, the 77 reading will drop out and the higher ones will have to be averaged instead. It's the fourth-highest reading at a monitor from the entire ozone season that then gets averaged with the previous two year's fourth-highest readings from that same monitor to determine "attainment" (simple!). Denton recorded a reading of 92 ppb on Friday (so far it's worst reading), so that rolling three year average of 79 based on Saturday's fourth-highest 77 ppb result is likely to rise, along with summer temps.

The monitor in Pilot Point has three exceedences and only needs one more to make it the site of the second official DFW smog violation of the season. After that, there's Keller, Grapevine, and Eagle Mountain Lake that have two exceedences each. Today (Tuesday the 9th) is an Ozone Alert Day, so we could see another round of high numbers. If you want to keep track of what the highest four readings are at every DFW ozone monitor, you can check them out all summer long at this Texas Commission on Environmental Quality website.

Remember folks, the State of Texas predicted four years ago that we'd be seeing historically low levels of smog in 2015 because so many people would be buying new cars. That would be the same State of Texas that's now predicting we'll reach attainment by 2018 just by waiting for the feds to change the national gasoline standards. No other control measures are necessary to clean the air according to Austin. No new controls on the Midlothian cement kilns, the East Texas coal plants, or gas sources in DFW.

But by now you know there's a large gap between the state's predictions of DFW air quality and the real thing. Despite five or so different past air plans for DFW since 1991, none has achieved its goal on time. Be safe out there. Don't inhale too deeply today.