Take Another Hit – It Was the Best June for DFW Breathing Since 2007

If this unseasonable cooler weather is making it seem like you're spending summer someplace other than DFW, it's also been the best "ozone season" in the region in seven years.

In the month that just ended, we only had four monitors on four days that violated the new 75 parts per billion smog standard that takes effect in 2018, and zero violations of the obsolete 1997 85 ppb standard. The maximum 8-hour reading was an 83 at the Denton Airport on June 3rd. Contrast that with last June: 54 violations of the 75 ppb standard and 27 violations of the 85 ppb standard over 9 days. Or 2011 – 24 violations of the 75 ppb standard, 7 violations of the 85 standard.

In fact, you have to go back all the way to 2007 when we had five violations of the 75 ppb standard but no "exceedences" of the 85 ppb, to find as good a June for air quality as we just had. And there are only a couple of other Junes – in 2010 and 2000 that even come close to being as full of safe and legal air. That's the good news.

The bad news is that these years were all followed by worsening air quality trends, that is, they turned out to be aberrations. So if this pattern holds, we'll have to wait until next summer to put it in context. As always, weather has a lot to do with how bad or good our ozone season is. The cooler and wetter, the better. The dryer and hotter, the worse. Just as this summer's cooler temps seem like they're out of place, by next June we could be thinking the same thing about our reprieve from smog.

The good news is that there's no questions that declining emissions in almost every category (we're looking at you oil and gas) have had a positive impact on the numbers. That's your doing. After 20 years of citizen effort, there's a lot less pollution from the cement plant complex in Midlothian, the coal plant belt in East Texas, and the millions of vehicles on and off the road.

For the EPA and the state, 2013 comes a year too late to help them recover from a terrible 2011 "clean air plan" that was supposed to get us down below 85 ppb by watching people purchase new cars. The clock officially ran out on that plan June 15th. Sales of new vehicles are dramatically up, so there's real displacement as old gas guzzlers get traded in for more efficient models. Whether those trade-ins are enough to cancel out the still-exploding growth rate of the area and rising gas and oil activity remains to be seen. That's why the EPA uses a three-year rolling average to determine transgressions against the Clean Air Act, to minimize the impact of anomalies.

You're just going to have to stay tuned to find out whether the summer of 2013 is the exception to the rule, or the re-writing of the rules.