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Progress North Texas 2017


Air Quality

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Clean air is easy to take for granted. Yet, it is important to know that many federal, State and local efforts are underway to protect this precious resource. Since 1991, North Texas counties have been in nonattainment for ozone, and have been engaged in efforts to reduce emissions, protect health and comply with federal air quality requirements. These efforts have helped reduce ozone concentration levels from 102 parts per billion in 1998 to 80 ppb in 2016, as seen in the chart below. Although progress is being made, continued efforts and innovations are needed to keep up with the recently revised ozone standard and rapid population growth.

Ozone Standards

Under the Clean Air Act, the US Environmental Protection Agency established the National Ambient Air Quality Standards, or NAAQS, designed to protect human and environmental health. Six criteria pollutants – lead, carbon monoxide, nitrogen dioxide, ozone, particulate matter and sulfur dioxide – are regulated under the NAAQS. North Texas meets the federal standard for all except ozone.


this is the ozone progress chart for North Texas.

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Accordingto the EPA, ozone attainment is reached when, at each monitor, the Design Value (three-year average of the fourth-highest daily maximum 8-hour ozone concentration) is less than or equal to 70 parts per billion.

The EPA is periodically required to review and revise ozone standards to ensure they protect human health. In 2015, after a full review of the available scientific literature on health and welfare effects of ozone, the EPA released the 2015 ozone standard. Notable changes include:

• Reducing the ozone standard from 75 ppb to 70 ppb

• Extending the ozone monitoring season for North Texas by one month (now from March 1 through November 30)

• Updating requirements to modernize and streamline the Photochemical Assessment Monitoring Stations network, which helps provide information on ozone formation and transport

Currently, 10 counties in North Texas are designated as nonattainment for ozone. Hood County could join Dallas, Collin, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant and Wise counties to form the new nonattainment area under the 2015 designation.

Role of NCTCOG

Serving as the metropolitan planning organization for the 12-county region, NCTCOG and the RTC are required to ensure transportation planning and development activities conform to the "emissions budgets" set for the region in the State Implementation Plan. The SIP is a regional air quality plan outlining how ozone concentrations will be reduced in the nonattainment area.

In North Texas, the RTC takes an active role in assisting with development of SIP revisions. This includes help with air quality technical planning and implementation of strategies at the local level to enhance federal and state efforts. Numerous other regional stakeholders, including local governments and business coalitions, also support this process and facilitate implementation. As a result of these efforts and improved vehicle technologies, ozone levels in the region continue to improve. Even though there are more people living, working and commuting in the area, resulting in more miles being driven, the levelsof ozone-creating pollutants continue to decline.

Ozone and Health

Unlike many pollutants, ground-level ozone is not produced directly by an emission source. It does not come directly out of a vehicle tailpipe or from a smokestack. Instead, it is the result of a reaction of other pollutants – nitrogen oxides (NOx) and volatile organic compounds (VOC) – that mix in the presence of sunlight and heat.


Clinical studies indicate prolonged exposure to elevated concentrations of ground-level ozone may reduce lung function, increase the frequency of asthma episodes and reduce the body's ability to resist respiratory infections. High ozone concentrations also pose a risk to the environment, wildlife and agriculture. Monitors are placed in strategic locations around the region and provide ongoing feedback about ozone concentrations.

Ozone in the Region

NCTCOG and the RTC are focusing on reducing NOx and VOCs, which are called precursor pollutants, in order to reduce ozone. In 2017, most NOx emissions (67 percent) are expected to come from mobile transportation sources. Therefore, air quality initiatives in the region are focused on reducing pollution from this sector, especially from cars and trucks.

Air Quality Programs

NCTCOG staff administers many air quality programs, makes policy recommendations, participates in partnerships and supports other stakeholders in their own emissions-reducing activities. NCTCOG programs help individuals, fleet operators and freight companies contribute to cleaner air. Programs concentrate on light- and heavy-duty vehicles and equipment. NCTCOG works with local governments, the Texas Commission on Environmental Quality, the EPA and DOE to improve air quality.




The region's air quality also benefits from efforts to repair and replace older vehicles. Older vehicles typically pollute more, but not everyone can afford to replace their vehicles with cleaner-burning ones. Administered locally by NCTCOG, AirCheckTexas Drive a Clean Machine provides qualifying motorists vouchers worth up to $3,000 toward vehicle replacement ($3,500 for hybrids and some other fuel efficient models) or repair vouchers of up to $600.

A chart showing the NOx contributionsfrom mobile sources.
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North Texans whose vehicles have failed the emissions portion of the State inspection or are at least 10 years old are encouraged to apply for assistance if they meet the income criteria. Since the program's creation, AirCheckTexas has helped repair or replace more than 66,000 vehicles. Additionally, the program helped to reduce emissions of approximately 90.51 tons of NOx and 24.47 tons of VOCs during FY 2016 alone.

More than $31 million is available through the program. This is one of many programs designed to improve the region's air quality. For more information on NCTCOG air quality programs, visit Volkswagen Settlement In 2016, courts determined Volkswagen had violated the Clean Air Act by selling diesel vehicles equipped with "defeat devices." These devices allowed vehicles to emit levels of NOx beyond what federal standards permit. This ruling resulted in a settlement of over $20 billion, including two different portions that could bring substantial investment in clean vehicle projects to North Texas, where more than 10,000 vehicles were affected by the settlement.First, the Environmental Mitigation Trust consists of $2.9 billion. Texas could receive up to $209 million to be used on NOx mitigation efforts. Eligible actions could include projects aimed at doing the following:

• Reducing NOx from heavy-duty diesel sources near population centers

• Replacing or repowering older engines for newer engines at a rail switchyard

• Replacing older transit buses with new electric-powered

Second, through the Zero Emission Vehicle Investment, $1.2 billion will be available to states other than California to support the increased use of zero-emissions vehicle technologies, including development and maintenance of related infrastructure. NCTCOG has submitted a proposal to Electrify America — the organization established by Volkswagen to manage the ZEV Investment
program — outlining the region's plans to address key electric vehicle infrastructure gaps and build awareness of EVs. Proposed actions include developing a highspeed, intercity EV charging network and identifying multi-family properties and workplaces best suited to support EV charging goals.

NCTCOG is engaged with other stakeholders to provide comments on potential investments. For more information about the settlement, visit

Chart with featured air quality initiatives.



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