EPA’s SO2 NAAQS findings would mandate coal emissions reductions in Texas

The Sierra Club on Nov. 30 complimented the U.S. Environmental Protection Agency for mandating SO2 emissions cuts under the National Ambient Air Quality Standards (NAAQS) at Luminant’s Martin Lake, Big Brown and Monticello coal plants in East Texas.

“This final decision is an important step in compelling the state of Texas to create a plan to address the problem and protect the communities living in the designated areas from unsafe air pollution,” said the club.

Chrissy Mann, senior campaign representative for the Sierra Club’s Beyond Coal Campaign, said: “The Sierra Club applauds today’s action by the EPA to identify areas in Texas around dirty, outdated coal plants where the air is unsafe to breathe because of high levels of sulfur dioxide pollution. These designations are a crucial first step to pushing Luminant – the biggest sulfur dioxide polluter in the state – to take responsibility for their pollution. … We hope that Texas officials will take today’s final rule seriously and create a plan to reduce pollution from these old coal plants and ensure that these vulnerable communities are protected from dangerous levels of sulfur dioxide pollution.”

Under the Clean Air Act (CAA), EPA must designate areas as “unclassifiable,” “attainment,” or “nonattainment” for the 2010 1-hour SO2 primary NAAQS). Section 107(d) of the CAA defines a nonattainment area as one that does not meet the NAAQS or that contributes to a NAAQS violation in a nearby area, an attainment area as any area other than a nonattainment area that meets the NAAQS, and an unclassifiable area as any area that cannot be classified on the basis of available information as meeting or not meeting the NAAQS.

July 2 of this year was the deadline established by the U.S. District Court for the Northern District of California for the EPA to designate certain areas. This deadline was the first of three deadlines established by the court for the EPA to complete area designations for the 2010 SO2 NAAQS. The EPA notified the areas subject to the July 2 deadline of its intended designations on March 1, including the four Texas areas addressed in this Nov. 29 supplemental action.

The EPA issued final designations for the majority of these areas on June 30. However, before meeting the July 2 deadline, the EPA and plaintiffs, who are parties to the consent decree that gave rise to the court order, agreed to extensions for a limited number of the subject areas in Texas:

  • Freestone County, site of Luminant’s Big Brown Steam Electric Station;
  • Titus County, site of Luminant’s Monticello Steam Electric Station;
  • Rusk County, site of Luminant’s Martin Lake Electrical Station; and
  • Milam County, site of Luminant’s Sandow Power Plant.

The deadline for issuing a designation for these four areas was extended to Nov. 29. These final designations are based on an assessment and characterization of air quality through ambient air quality data, air dispersion modeling, other evidence and supporting information, or a combination of the above.

As an example of the findings, the Freestone County area contains a stationary source that, according to the EPA’s Air Markets Database, emitted in 2012 either more than 16,000 tons of SO2 or more than 2,600 tons of SO2 and had an annual average emission rate of at least 0.45 pounds of SO2 per one million British thermal units (lbs SO2/mmBTU). As of March 2015, this stationary source had not met the specific criteria in the consent decree for being “announced for retirement.” Specifically, in 2012, the Big Brown station emitted 60,681 tons of SO2, and had an emissions rate of 1.59 lbs SO2/mmBTU.

In a September 2015 submission, Texas provided no formal recommendation for the specific area surrounding the Big Brown station. Instead, Texas provided a general recommendation of unclassifiable/attainment for the 243 counties located in the state, including Freestone County, that do not have any operational SO2 regulatory monitors. On Feb. 11, 2016, the EPA notified Texas that it intended to designate the portions of Freestone and Anderson Counties, Texas, as nonattainment.

Much of the SO2 modeling for Big Brown was provided by the Sierra Club. EPA wrote in the Nov. 29 finding: “After careful evaluation of the information provided by Sierra Club, as well as other available relevant information, the EPA designates the area around Big Brown in Freestone and Anderson Counties, Texas, as nonattainment for the 2010 SO2 NAAQS.” It later added: “Given that modeled concentrations are 64% above the standard and that several factors are conservative and would tend to result in Sierra Club’s modeling being biased lower for the maximum modeled concentrations, our technical assessment of the available information concludes that the Sierra Club’s modeling results are likely underestimating the maximum impacts.”

Said a similar finding about Titus County: “After careful evaluation of the state’s recommendation, all timely comments and information received during the state and public comment period, and additional relevant information as discussed in this document, the EPA is designating the area around Monticello Steam Electric Station, Texas, as nonattainment for the 2010 SO2 NAAQS.”

Said the finding for Rusk County: “After careful evaluation of the state’s recommendation, all timely comments and information received during the state and public comment period, and additional relevant information as discussed in this document, the EPA is designating the area around Martin Lake Steam Electric Station as nonattainment for the 2010 SO2 NAAQS.”

Said the finding for Milam County: “After careful evaluation of the state’s recommendation, all timely comments and information received during the state and public comment period, and additional relevant information as discussed in this document, the EPA is unable to determine whether the area around the Sandow Power Plant (Unit 4) is meeting the 2010 SO2 NAAQS or is contributing to an area that does not meet the NAAQS, and therefore is designating the area as unclassifiable. Specifically, the area is comprised of all area within Milam County borders.”

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.