Air monitoring during hurricanes

In August 2020 TCEQ took its stationary air monitors in Beaumont and Houston offline prior to Hurricane Laura’s landfall, triggering considerable criticism and a lot of questions. We’ve asked Cory Chism, Deputy Director of TCEQ’s Monitoring Division, to explain.

Before getting into why TCEQ shuts off its air monitors in the path of a storm, explain the role of the stationary monitors, how many of them there are, where they’re located, etc.

Texas maintains one of the most extensive air monitoring programs in the nation.

The program relies on a network of stationary monitors that provide data used to measure compliance with federal air quality standards, evaluate trends in regional air quality, and help determine the causes, nature, and behavior of air pollution in Texas, including possible high concentrations of ozone and particulate matter.

The network consists of more than 200 stations across the state, equipped with over 400 individual pollutant samplers. Each air monitoring station 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.

Meteorological parameters, such as wind speed and direction, temperature, relative humidity, as well as solar and ultraviolet radiation, also help us evaluate air quality.

TCEQ’s air monitoring network data can be viewed through the GeoTAM website. In addition, more information can be found on TCEQ’s air monitoring network here.

Are the stationary monitors designed to isolate sources of pollution during storms?

No, they’re not – that’s one of the biggest misconceptions about the monitors. They measure ambient concentrations of pollution but are not intended or equipped to pinpoint emissions from specific sources.

Why do you take the monitors offline?

The monitors are not designed to withstand hurricane-force conditions and can be damaged by winds, flooding, or even electrical power surges. We secure monitors directly in the storm’s path so that they will be available once the hurricane has passed.

They don’t do us or anyone else any good if they’re destroyed.

This equipment isn’t cheap. We have nearly $5 million in monitoring assets in the coastal regions of Texas alone. Securing them protects capital assets from loss or damage so that they’re there when we need them.

In advance of a hurricane’s projected landfall, TCEQ’s Regional staff power down all instruments and disconnect them from power sources. They also elevate instruments and equipment from lower shelves, cabinets, or the floor, and lower the meteorological towers. These precautions are taken to reduce potential instrument/equipment damage from electrical power surges, rainwater fouling sampling lines, flooding, and wind damage. In some cases, instruments and equipment are removed from the site and stored in secure locations.

But these storms are extremely powerful, and unpredictable.  For example, despite these usual precautions, three of the agency’s monitoring stations sustained damage in the Beaumont-Port Arthur area during Hurricane Laura. The air sampling inlets at both the Nederland High School station and Port Arthur West station were dislodged from the station and filled with water. Also, the power lines and station power pole were blown down at the Orange 1st Street station.

We had similar problems during Hurricane Harvey, when our monitors sustained flood damage at the Houston East and Milby Park stations in Houston as well as the Port Arthur City Service Center and Orange 1st Street stations. So, we do our best to protect the monitoring assets, but it’s not a guarantee.

Some critics point to a critical period during storms when air monitoring stations are shut down, and TCEQ personnel can’t measure pollutants with mobile equipment. What do you say about that?

We bring our stationary network back to full operational status as soon as possible and as soon as it is safe to do so. Hurricane damage following a storm including flooded roads, downed power lines, and other infrastructure damage may limit our ability to respond in some areas.  Nevertheless, we do our best to act quickly.  For example, following Laura’s landfall on Aug. 27, we began bringing monitors back online the same day in Houston and the following day in Beaumont.

Conditions during a hurricane are not optimal for air monitoring and, as strange as it might sound, actually create climate conditions that decrease pollutants in the air, because high winds cause greater dispersion and heavy rains can wash pollutants from the atmosphere.

That said, we recognize that air monitoring is critical following a hurricane as facilities are coming back online. To address this, TCEQ deploys investigators to survey industrial sites and neighborhoods bordering facilities with handheld monitors, as soon as it is safe to do so. We also deploy our mobile monitoring vans and can quickly survey and identify areas of potential concern.

What other equipment or technology does TCEQ deploy to monitor air quality during storms?

We have a variety of tools at our disposal that are deployed depending on specific circumstances and needs. The equipment we use most frequently are handheld monitors. These devices are used as a screening mechanism to take instantaneous readings to help assess air quality.

Following Hurricane Laura, as monitoring stations were being brought back online handheld monitors and optical gas imaging cameras were used to evaluate air quality in neighborhoods near industrial facilities.

EPA staff also deployed its Trace Atmospheric Gas Analyzer mobile monitoring system and Airborne Spectral Photometric Environmental Collection Technology (ASPECT) aircraft to monitor air quality. These tools provided effective ways to quickly identify sources of drifting plumes so that swift action could be taken to address the cause of emissions.

These data are publicly available here.

TCEQ also recently upgraded its fleet of mobile air monitoring vans with mass spectrometers that can sample in real-time for a pollutant list of more than 1,000 compounds, including benzene, toluene, 1,3-butadiene, and styrene, among others. We also purchased a Rapid Assessment Survey van that focuses on a narrower pollutant list and can collect data very quickly while on the move.

The new van allows us to quickly map air concentrations in an area and identify locations for additional sampling. The new survey van instrumentation also has an integrated GPS that, through the instrument software, produces color-coded animations illustrating the concentrations of pollutants measured along the van’s survey route.

It’s pretty cool stuff, and it helps us do our job better.

Cory Chism

Richard “Cory” Chism has served as Deputy Director of TCEQ’s Monitoring Division since 2011, where he oversees the agency’s air monitoring programs. After joining TCEQ in 1999 as an environmental specialist in the Air Permits Division, Cory has held in a variety of positions, developing a diverse background in air programs that includes permitting, air quality planning, emissions banking, and air monitoring.  Cory graduated from Texas A&M University in 1994 with a Bachelor of Science degree in Ecology.