A new report prepared by the Texas Commission on Environmental Quality’s Toxicology, Risk Assessment, and Research Division, in concert with the agency’s Office of Compliance and Enforcement, examines several high-profile emergency events, including Hurricane Laura and Winter Storm Uri.
The analysis provides details on the release of emissions during shutdowns and startups before and after natural disasters and following certain industrial accidents.
In its report, a summary of which was presented to the full Commission in a
work session Thursday, TCEQ staff derived data from several sources, including stationary air monitors, mobile monitoring vehicles, handheld instruments, and emissions reports.The report provides details on TCEQ air monitoring efforts following such incidents over varying lengths of time – at a minimum several days, and in some cases, depending on conditions and air quality measurements, for weeks or even months after the initial event.
Importantly, the review shows that industrial facilities experiencing shutdowns and startups related to natural disasters do not restart their operations all at once. This finding, combined with the scarcity of air quality impacts found in the data, suggests that wide-scale regional deployment of agency personnel to conduct prolonged handheld air quality and mobile monitoring of affected areas during startup operations is often unnecessary.
A key finding of the report is that, of the 3.6 million monitoring data points collected after hurricanes and other natural events, only 23 measurements were higher than a health-based comparison value. These chemical concentrations were only slightly higher than their comparison value and exposure would not be expected to cause health effects.
However, the analysis indicates that continued monitoring of air quality during and after an industrial incident, with mobile vans and handheld devices, will generally remain necessary.
“While each event is unique and TCEQ will tailor its response to meet specific conditions, data compiled in the analysis will be helpful in deploying resources more effectively,” said the agency’s Executive Director Toby Baker.
“In the future, we’ll be able to more efficiently provide monitoring without pulling unnecessary resources away from our mission-critical activities across the state.”
TCEQ personnel examined the following natural disasters and industrial accidents:
- Hurricane Harvey, August-September 2017
- ITC industrial fire, March 2019
- TPC industrial fire, November 2019
- Hurricane Laura, August 2020
- Hurricane Delta, October 2020
- Winter Storm Uri, February 2021
For this report, TCEQ tracked air monitoring efforts for some or all of the following common compounds across the data streams:
- 1,3-Butadiene
- 1-Butene (1-butylene)
- Acetylene
- Benzene
- Cyclohexane
- Ethylbenzene
- Isobutane
- m/p-Xylene
- n-Hexane (hexane)
- n-Octane (octane)
- o-Xylene
- Propylene
- Styrene
- Toluene
Measured concentrations of chemicals were compared to various benchmark comparison values to determine the number of monitored chemical exceedances within each dataset.
TCEQ uses a variety of tools to assess air quality. The agency maintains a network of more than 200 stationary air monitors across the state, each of which can include one or more samplers that measure for ozone, nitrogen oxides, particulate matter, carbon monoxide, sulfur dioxide, and lead, as well as air toxics such as benzene, toluene, and 1,3-butadiene. Network data can be viewed on the GeoTAM website
.
To further enhance its monitoring efforts, TCEQ has permanently stationed three air monitoring vehicles along the Gulf Coast in densely industrialized areas. The vehicles are in addition to three upgraded air monitoring vans based in the agency’s Austin headquarters, which feature advanced mass spectrometers capable of sampling for more than 1,000 pollutants. These and other instruments allow investigators to better map and analyze concentrations of various chemicals and compounds during natural disasters and industrial events.
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