Texas's Air: What's The Main Pollutant?

Texas, the second-largest US state by area and population, has a serious air pollution problem. The state's air quality is monitored by the Texas Commission on Environmental Quality (TCEQ), which found that in 2019, an industrial facility in Texas illegally polluted the air on every single day. The TCEQ has identified ozone (O3) and particulate matter (PM2.5 and PM10) as the two main pollutants that can make the air unhealthy. These pollutants can irritate the respiratory system, trigger asthma attacks, harm lung development in children, and even be deadly. While Texas has made progress in reducing greenhouse gas emissions from the electricity sector, it remains the largest consumer of coal in the US, and its power sector's emissions exceed those of all but six states. The state's biggest polluters are power companies and refineries, with transportation and industry also contributing significantly.

Fossil fuels and refineries

Texas is the largest annual emitter of carbon dioxide in the United States, releasing 683.2 million metric tons in 2019. The state's emissions are nearly double that of second-place California, and if Texas were a country, it would be the world's eighth-largest emitter. The three main sources of these emissions are transportation, industry, and electricity generation, with the fossil fuel industry being the most significant contributor.

Texas extracts, produces, and refines more crude oil and natural gas than any other state, and is home to 70% of the nation's petrochemical production capacity. The Motiva Refinery in Port Arthur, for example, is one of the largest refineries in the US, producing 720,000 barrels of oil daily. ExxonMobil also owns a Baytown complex that houses a refinery, a chemical plant, and an olefins unit.

The state's greenhouse gas emissions are largely driven by the electric power, industrial, and transportation sectors. In addition to refineries, Texas is home to several power plants that are among the top climate polluters in the country, such as the W. A. Parish Generating Station, which emitted 12.4 million metric tons of greenhouse gases in 2022, and the Limestone Electric Generating Station, which emitted 7.4 million metric tons of GHG emissions in the same year.

The state's heavy reliance on fossil fuels and refineries has led to significant air pollution, with Texas emitting more than twice as many greenhouse gases as California. In 2019, industrial facilities in Houston, Texas, emitted over 23 million pounds of unauthorised air pollutants, and there was an instance of illegal air pollution by an industrial facility in the state every day of that year. Texas is known for its blue skies and bright summers, but hot weather and pollutants from cars, trucks, and factories can make the air unhealthy, especially for those sensitive to air pollution.

Ozone (O3) and particulate matter (PM2.5 and PM10) are the two main contributors to unhealthy air quality. Ozone pollution, sometimes called smog, irritates the lungs and can shorten lives. Particle pollution, which includes pollutants such as nitrogen oxides, benzene, and butadiene, can exacerbate asthma, increase the risk of lung cancer, and cause early death, heart attacks, and strokes.

Despite Texas's historic dependence on fossil fuels, there is hope for a transition to a net-zero future. A University of Texas study found that decarbonizing the electric grid, increasing vehicle electrification, and reforestation could help Texas achieve net-zero emissions in fewer than thirty years, while also increasing jobs and the state GDP.

Industrial emissions

Texas has one of the most robust air monitoring networks in the United States, with over 200 monitoring stations serving over 25 million Texans. This network assists the Texas Commission on Environmental Quality (TCEQ) in monitoring compliance with federal air quality standards, as well as evaluating air pollution trends and studying the formation and behaviour of pollutants.

Despite this, Texas is one of the world's largest global warming polluters and has been ranked as the eighth-largest emitter in the world. The state's biggest sources of emissions are transportation, industry, and electricity generation, with most emissions coming from the fossil fuel industry. Texas extracts, produces, and refines more crude oil and natural gas than any other state and is home to 70% of the nation's petrochemical production capacity. In addition, Texas is the largest consumer of coal in the US, and the state's power sector emissions alone exceed those of entire economies of all but six states.

The state's industrial facilities have been found to emit pollutants over and above the permitted limits. In 2019, companies in Houston, Texas, discharged more than 170 million pounds of unauthorised toxins into the air. These excess emissions can occur due to equipment malfunctions, maintenance work, or during the start-up and shutdown of facilities. The pollutants emitted include particulate matter, nitrogen oxides, benzene, and butadiene, which can irritate the respiratory system and exacerbate asthma, and in some cases, cause cancer.

To combat air pollution, Texas has passed laws and imposed standards for certain contaminants. Wind power is becoming more widespread and now accounts for 17% of the state's electric grid capacity. Texas has also discovered significant natural gas reserves in the Permian Basin, which has helped reduce coal's market position.

Vehicle emissions

Texas has implemented various measures to address vehicle emissions and improve air quality. One notable initiative is the “Two Steps, One Sticker” program introduced in March 2015. This program combines vehicle inspection and registration renewal processes, requiring vehicles to pass an inspection and, if necessary, an emissions test before being legally registered. This program is designed to ensure that vehicles meet emissions standards and reduce their impact on air quality.

The Texas Commission on Environmental Quality (TCEQ) and the Texas Department of Public Safety (DPS) play crucial roles in managing vehicle emissions. They collaborate on enhanced vehicle emissions inspections in specific counties, aiming to improve air quality and protect public health. These inspections are integrated with the annual emissions inspection program and focus on areas with high populations and industrial activity.

Remote sensing technology is also employed to randomly inspect vehicle emissions on highways, contributing to a central database for analysis and compliance monitoring. Additionally, Texas follows federal regulations set by the Environmental Protection Agency (EPA) regarding vehicle emissions standards, which vary based on vehicle type and model year.

By enforcing emissions testing and compliance, Texas aims to mitigate the adverse effects of vehicle emissions on the environment and public health. High levels of ozone and particle pollution, often caused by vehicle emissions, can irritate the lungs, trigger asthma attacks, harm lung development in children, and even lead to premature deaths. Therefore, the state's efforts to reduce vehicle emissions are vital to safeguarding the well-being of Texans and creating a more sustainable future.

Ozone pollution

In Texas, ozone is one of the two main things that can make the air unhealthy, the other being particulate matter (PM2.5 and PM10). Texas has one of the most robust air monitoring networks in the country, with over 200 monitoring stations serving over 25 million Texans. This network assists the Texas Commission on Environmental Quality (TCEQ) in monitoring compliance with federal air quality standards and studying air pollution trends and behaviours. TCEQ meteorologists use historical data and ozone-prediction models to forecast when conditions will be favourable for the creation of elevated ozone levels, so that citizens, businesses, and industries can take steps to reduce ozone-forming pollutants. Despite these efforts, Texas air monitors recorded 43 days in 2022 when ozone concentrations were high enough to be considered unhealthy by the Environmental Protection Agency (EPA). This was the most in a decade and double the number of unhealthy ozone days recorded by the same point in 2021.

The EPA has recently cracked down on the Houston and Dallas regions for violating national ozone standards, and is considering redesignating parts of the Permian Basin in West Texas as not meeting federal standards on ozone pollution. The EPA has also proposed a rule that would require Texas and about two dozen other states to cut ozone pollution from power plants and industrial sources, strengthening the "good neighbour" regulation. Texas politicians and state agencies have urged the EPA to withdraw its proposal, arguing that it oversteps the agency's authority and ignores the potential impact on the state's electric grid reliability.

To protect themselves from the harmful effects of ozone pollution, Texans can check the air quality forecast in their community and avoid exercising or working outdoors when unhealthy air is expected. They can also take steps to reduce their own emissions, such as limiting driving and idling, refuelling vehicles in the late afternoon or evening, and maintaining their vehicles and yard equipment.

Sulphur dioxide

In Texas, coal-burning power plants and petrochemical facilities are major sources of sulphur dioxide emissions. In 2018, Texas polluters emitted 282,000 tons of sulphur dioxide, a 25% reduction from 2017, attributed to the closure of three sites owned by the coal mining company Luminant. Despite this reduction, Texas has struggled to meet air quality standards for sulphur dioxide, with counties designated as nonattainment or unclassifiable for the 2010 SO2 standard.

The W. A. Parish Plant near Houston is the second-largest source of sulphur dioxide in Texas. While the plant has implemented measures such as catalytic converters and electrostatic precipitators to reduce sulphur dioxide emissions, it has faced criticism for not meeting federal health-based standards for particulate matter. The Texas Commission on Environmental Quality (TCEQ) has a robust air monitoring network with over 200 stations serving over 25 million Texans. TCEQ works to monitor and regulate sulphur dioxide emissions, with rules in place to limit ground-level concentrations and set allowable emission rates.

To control sulphur dioxide pollution, Texas has implemented rules as part of the State Implementation Plan strategy to meet the National Ambient Air Quality Standard. These rules limit ground-level sulphur dioxide concentrations and set allowable emission rates for sources such as power plants. "Scrubbers" are also used to remove sulphur dioxide before it escapes into the atmosphere, although stricter regulations on their use have been advocated by some.

Overall, sulphur dioxide is a significant air pollutant in Texas, with power plants and petrochemical facilities being major contributors. TCEQ works to monitor and regulate emissions, but the state has faced challenges in meeting air quality standards. Implementing additional measures and strengthening regulations may be necessary to further reduce sulphur dioxide pollution in Texas.

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