Frost Tower on the San Antonio skyline downtown.
The San Antonio skyline. Credit: Bonnie Arbittier / San Antonio Report

Asking the public to drive less on bad-air days, leveraging funding to replace dirty vehicles in local fleets, and identifying specific sources of pollution near air quality monitors were among the ideas City officials proposed to meet a critical December 2020 deadline to improve San Antonio’s air quality.

That’s according to a plan to deal with the city’s ozone emissions that interim Assistant City Manager Colleen Bridger presented to City Council members during a Wednesday afternoon session. Bridger, formerly director of San Antonio’s Metropolitan Health District, was tasked last year with finding ways to bring San Antonio’s ozone levels into compliance with a federal health standard of 70 parts per billion.

The goal is to avoid stricter regulations imposed by the U.S. Environmental Protection Agency, which in July declared Bexar County’s ozone levels officially in violation.

Failure to get San Antonio’s three-year average ozone levels below 70 parts per billion in December 2020 could trigger more stringent regulations that raise air quality permit costs for businesses and could delay planning for new transportation projects.

“This is about getting ahead of what we know will ultimately be a mandate soon, but we also do it, most importantly, for public health,” Mayor Ron Nirenberg said at the meeting.

San Antonio’s ozone levels go up and down each year but have been on a general decline from a recent high of more than 90 parts per billion in 2004.

In October 2015, the EPA lowered the standard from 75 parts per billion to 70 based on research that showed the benefits to public health. From 2015 to 2017, the period of record for the EPA’s decision, San Antonio’s average ozone levels were calculated at 74 parts per billion.

Ozone – three oxygen atoms bound together – can irritate and damage the lungs and has been linked to chronic lung conditions. People with asthma and other sensitive groups face a higher risk of attacks during high-ozone conditions.

The most recent version of a study by New York University and the American Thoracic Society estimates that the San Antonio-New Braunfels area has 34 preventable deaths per year and more than 126,000 “impacted days” when a person has to restrict activity or miss work or school because of respiratory symptoms. The study compares San Antonio’s current ozone levels to the society’s recommended levels of 60 parts per billion.

Ozone forms when emissions of nitrogen oxides from power plants, industrial sites, and vehicle tailpipes interact with volatile organic compounds from outdoor chemical use and other sources in the presence of heat and sunlight. In San Antonio, high ozone season generally lasts from March through November.

Modeling by the Alamo Area Council of Governments (AACOG) indicates that San Antonio’s ozone levels will likely drop below 70 parts per billion by 2023, mostly driven by improvements in vehicle efficiency, though that would not be fast enough to avoid stricter regulations.

At the meeting, Bridger laid out a what she called a “targeted intervention” that could immediately bring down average ozone levels by the end of 2020.

“The main reason is it’s a public health issue: Ozone is bad for your lungs,” Bridger said. “We also care about it because of potential economic costs.”

Assistant City Manager Colleen Bridger
Interim Assistant City Manager Colleen Bridger presents a plan to City Council for improving the city’s air quality. Credit: Scott Ball / San Antonio Report

Ideas included media and education campaigns to encourage the public to drive less during high-ozone days, as well as a push for the City to examine how its employees could work flexible hours, telecommute, or rely on buses or vanpools to avoid driving to and from work when possible.

The City also plans to apply for some of the $60.4 million in Volkswagen settlement funds available to the region to help replace older diesel vehicles in its fleet. Bridger said the Texas Commission on Environmental Quality (TCEQ), which administers the funds, has not yet opened its application process.

“They are still in negotiations with the [Volkswagen] trust, so we are still waiting for them to let us know how they wish to proceed,” Bridger said.

Metro Health has also issued a request for proposals for contractors to help them identify potential sources of ozone-forming pollution with in a 10-mile radius of the three air quality monitors used for regulatory purposes in San Antonio. That idea came out of work by air quality expert Harvey Jeffries that the City commissioned last year.

“We are looking for a consultant … to come in and help us identify point sources, and then we will work with the emitters to reduce those emissions,” Bridger said.

In Texas, the TCEQ is in charge of regulating air quality, but the City has an air quality ordinance that requires businesses that emit above a certain level to register their emissions with the City.

Right now, the largest known sources of ozone-forming pollution are CPS Energy’s coal- and gas-fired power plants and a handful of heavy industrial sites. However, Bridger said smaller sources might also be driving the ozone levels measured at the air monitors.

“It’s the gas stations, it’s the paint shops that are inadvertently causing some emissions that they don’t know about,” she said.

Russell Seal, a member of the local Alamo Group of the Sierra Club, criticized the idea of focusing only on the areas right next to the air monitors. He suggested one big way to improve ozone conditions this season would be for CPS Energy to not run its Spruce coal plant as frequently as usual.

“Ozone is broad-based, it takes time to form,” Seal said. “To try to just control it right around the monitors, all these things are good, but it needs to be more broad-based.”

AACOG modeling indicates that CPS Energy’s closure of its Deely coal plant will likely have a huge impact on ozone levels, reducing San Antonio’s average by 0.5 parts per billion, Bridger said.

A view from an access road at Calaveras Power Station of (from left) CPS Energy Spruce units and Deely units.
A view from an access road at Calaveras Power Station of (from left) CPS Energy Spruce units and Deely units. Credit: Bonnie Arbittier / San Antonio Report

At the meeting, Councilman Clayton Perry (D10), asked Bridger several times about the costs associated with these measures. Bridger estimated that altogether they would cost around $400,000.

“We’ll quantify that better, but it’s significantly less than the penalties,” Bridger replied.

Mario Bravo, Texas outreach specialist with the Environmental Defense Fund, compared Perry’s concerns about costs to the debate over San Antonio’s Climate Action and Adaptation Plan, which is now in the midst of a contentious public vetting.

“They’re focusing on costs when they should be focused on these savings from these investments,” Bravo said.

A 2017 economic modeling study commissioned by AACOG found that additional air quality regulations are costing Bexar County up to tens of billions in economic losses per year as a result. However, the researchers said they got “very little information about companies actually considering not expanding or locating in the region” because of additional ozone regulations.

Councilman John Courage (D9) asked Bridger to confirm that “we’re not telling [residents] they need to change how they drive or where they go or when they can drive, or anything like that.”

“We’re asking them if they would please on days with high ozone limit the use of their car or do so early in the morning or late at night,” Bridger said. “It’s voluntary.”

The ozone plan is set to go before City Council for approval in May.

Avatar photo

Brendan Gibbons

Brendan Gibbons is a former senior reporter at the San Antonio Report. He is an environmental journalist for Oil & Gas Watch.