By Neil Carman, Clean Air Director
The major Texas urban areas of Dallas-Fort Worth and Houston-Galveston-Brazoria have had the worst ozone (aka smog) pollution in the state since the 1970s, when ozone monitoring began. In fact, these two areas have had among the nation's worst smog for decades. While it's true that smog levels have declined (thanks to EPA standards) with cleaner vehicles, less factory pollution, and cleaner energy, Texas has a long ways to go to achieve clean air. What does the new ozone standard mean for these areas and other urban areas across Texas?
Background
The four largest urban areas of Dallas-Fort Worth, Houston-Galveston-Brazoria, San Antonio, and El Paso face serious challenges ensuring healthy air for more than 18 million people (70% of Texas population). Children and seniors are especially vulnerable to smog when levels are high, and asthmatics suffer more on bad air days having to use their inhalers more to breathe. Asthma medication is expensive and those lacking health insurance may have difficulty paying for the medications.
Dirty air is caused by tailpipe exhaust from motor vehicles and smokestack emissions from coal-fired power plants, oil refineries, chemical plants, oil & gas fracking, and other industrial facilities.
Texas ranks #1 in the nation in industrial air pollution.
How are bad air thresholds determined?
Currently, bad smog is defined as exceeding the EPA's ground level ozone standard of 75 parts per billion (ppb) for 8-hours. The EPA tightened the standard on October 1, 2015, with a new ozone standard at 70 ppb for 8-hours. Exceeding the ozone standard can result in "nonattainment" status by EPA. Four Texas areas are on the "nonattainment" track. Nonattainment means one or more monitors have a 3-yr average of 71 ppb or higher using 4th highest 8-hr ozone level.
What does the new standard mean for Texas cities?
EPA's national ozone data shows that three Texas urban areas have among the highest ozone levels in the country and a fourth, El Paso, also exceeds the new standard. San Antonio will become an ozone nonattainment area for the first time while three other high ozone areas have been in this bad air status before.
In the Dallas-Fort Worth area, which encompasses a 10-county area, 60% of monitors exceed the new standard, ranging from 71-83 ppb. DFW's big challenge is the large upwind regional transport effect caused by 12 coal plants – four in East Texas and eight in Central Texas. The worst DFW monitor, Denton Airport South, may be affected by local fracking emissions and coal plant transport. DFW has one of the worst smog problems in the U.S. for such a large urban region.
In the Houston-Galveston-Brazoria area, which encompasses eight counties, 62% of monitors violate EPA's new ozone rule with levels 71-80 ppb. One of Houston's big challenges is the large local effects of 500 industrial plants as well as many vehicles. Houston, like DFW, has one of the worst smog problems in the country. NRG's WA Parish coal plant is the largest source of smog pollution in the region.
Even towns near both the DFW and HGB areas are not safe, as both areas will probably expand to include a few more counties.
San Antonio has two monitors exceeding the new standard with levels up to 78 ppb. This will likely be a five-county nonattainment area. Eagle Ford Shale activities are contributing to the city's high smog levels.
The DFW, HGB, and San Antonio areas are all within the "Eastern Airshed" of Texas from the IH-35 corridor east to the Louisiana border, and this represents a huge concentration of industrial pollution and urban areas. The entire Eastern Airshed needs to become one large nonattainment region, as 14 of the 17 dirty coal plants are within this region, but the TCEQ has resisted this nonattainment concept as a way to bring in the rural coal plants and other large industrial plants.
El Paso, a one county area, is borderline with ozone at 72 ppb and receives some smog from Juarez.
Seven Texas areas will likely stay in attainment of the new EPA ozone NAAQS: Beaumont-Port Arthur, Austin-Round Rock-Georgetown, Waco-Temple, Longview-Tyler-Marshall, Corpus Christi-Victoria, Laredo, and the Lower Rio Grande Valley (Harlingen, McAllen).
What happens now?
The TCEQ will send recommendations to EPA in 2016 based on 2013-15 ozone levels, and then EPA will designate areas in "nonattainment" in 2017 using updated ozone for 2016. A clean air plan to reduce smog then has to be developed by the state and submitted to EPA for approval. The process takes years to carry out before smog levels decline.