SO2 emissions from the Martin Drake coal plant of Colorado Springs Utilities are low enough that the U.S. Environmental Protection Agency has decided on a preliminary basis not to declare the area around it in nonattainment of the SO2 NAAQS.
EPA on Feb. 16 sent out letters to various states about preliminary decisionns made regarding certain given areas in each of those states. Under section 107(d) of the Clean Air Act, EPA must designate areas as either “unclassifiable,” “attainment,” or “nonattainment” for the 2010 one-hour sulfur dioxide (SO2) primary national ambient air quality standard (NAAQS). The CAA defines a nonattainment area as one that does not meet the NAAQS or that contributes to a violation in a nearby area. An attainment area is defined as any area other than a nonattainment area that meets the NAAQS. Unclassifiable areas are defined as those that cannot be classified on the basis of available information as meeting or not meeting the NAAQS.
Colorado submitted updated recommendations to EPA in September 2015, ahead of a July 2, 2016, deadline for the EPA to designate certain areas established by the U.S. District Court for the Northern District of California in a decision that came out of an environmental group lawsuit. This deadline is the first of three deadlines established by the court for the EPA to complete area designations for the 2010 SO2 NAAQS.
The Colorado Springs 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 2, 2015, this stationary source had not met the specific requirements for being “announced for retirement,” which would exclude it from the process.
Specifically, in 2012, the Martin Drake Power Plant emitted 4,792 tons of SO2, and had an emissions rate of 0.56 lbs SO2/mmBTU. Pursuant to the March 2015 court-ordered schedule, the EPA must designate the area surrounding the facility by July 2, 2016.
In its submission, Colorado recommended that the area surrounding the Martin Drake Power Plant be designated as unclassifiable based on an assessment and characterization of air quality from the facility and other nearby sources which may have a potential impact in the area of analysis where maximum concentrations of SO2 are expected. This assessment and characterization was based on consideration of the data available to the state, including attaining monitoring data with fewer than three total years of data that Colorado did not determine was located in the area of maximum concentration.
Said an EPA technical document backing its Feb. 16 decision: “After careful review of the State’s assessment, supporting documentation, and all available data, the EPA agrees with the State’s recommendation for the area, and intends to designate the areas as unclassifiable. However, because the State did not provide specific boundaries in its recommendation, the EPA’s intended boundary consists of El Paso County.”
The Martin Drake Power Plant is located in Colorado Springs in the western portion of El Paso County.
The technical document noted about the plant: “The EPA recognizes that control strategies implemented after the release of the 2011 [National Emissions Inventory] may not be reflected, or may warrant further discussion. The State indicated that Colorado Springs Utilities (CSU) is currently in the process of installing SO2 controls on Units 5, 6 and 7 to comply with Regional Haze emission limits. At the time of this analysis, CSU plans to install dry sorbent injection (DSI) on Unit 5 and lime spray dryers or equivalent on Units 6 and 7 with target control operational dates by December 31, 2016 and compliance dates no later than December 31, 2017.”