Clean-air advocates and experts are urging state health officials to deny a request to declare the Martin Drake Power Plant area in compliance with federal sulfur dioxide emission standards.
"What we ask is for the Air Quality Control Commission to reject the recommendation of attainment and enforce the one-hour standard that is aligned with the science," said Zach Pierce, senior campaign representative in Colorado and New Mexico for Sierra Club's Beyond Coal initiative.
Whether the plant will be redesignated is to be decided during a Nov. 16 hearing in Denver by the Air Quality Control Commission of the state's Department of Public Health and Environment.
The Sierra Club, Environmental Defense Fund, 350 Colorado and the Center for Biological Diversity argued in public comments that the data collection method used in the air quality report submitted to the state health department did not comply with Environmental Protection Agency standards.
Under the EPA's 2010 1-Hour Sulfur Dioxide rule, operations that emit large amounts of sulfur dioxide (SO2) must prove that the source of the pollutant emits 75 parts per billion or less, on average, every hour. The reported amount represents an average of the one-hour measurements over three consecutive years.
The four groups argued that Colorado Springs Utilities and monitoring contractor AECOM Technical Service's decision to convert a 30-day SO2 emission average to a one-hour measurement doesn't comply with EPA guidelines.
The organizations also wrote that Utilities' background sulfur dioxide data were collected over one year - not three, as EPA requires - and that the data were collected 40 miles away in Pueblo rather than near the power plant.
Mark Salley, a spokesman for the Air Pollution Control Division, disagreed, saying the division worked closely with the EPA on the technical protocol for air quality monitoring.
"The modeling protocol, including the conversion of the 30-day emissions limit to a 1-hour value, was reviewed by EPA and is consistent with EPA guidance," Salley said in an email, adding that monitoring data never showed SO2 emissions above the federal limit, a classification called "nonattainment."
Utilities spokeswoman Amy Trinidad said the decision to use the conversion factor was made by the state health department, with guidance from the EPA.
"We notified CDPHE that the Drake Power Plant has demonstrated compliance with more stringent SO2 emissions limits mandated by Colorado's Regional Haze Compliance Schedule," Trinidad said. "These new mandates become effective at the end of this year."
The area around Martin Drake now is rated "unclassifiable" because of insufficient emissions data provided to the state in 2015.
In 2016, Utilities denied that SO2 discharge violations occurred at Martin Drake but refused to release the report that purportedly contains that emissions information.
Monument attorney and clean-air advocate Leslie Weise has reason to believe otherwise. In November 2016, Weise inadvertently received the report from the Colorado Court of Appeals.
The report shows that the Drake plant consistently exceeded federal limits on SO2 emissions, she said.
Utilities repeatedly denied her allegations.
Weise said the state health department's decision to "bypass" the rules and ignore data that prove SO2 emission exceedances is "offensive."
"CDPHE seems to be looking the other way, bending the rules," Weise said. "Here we are, breathing in this air from the plant in the middle of downtown that is spewing out this crap, and the state agency tasked with regulating it is saying, 'Oh, it's OK to avoid the rules.' No, it's not OK."
The EPA found that short-term exposure to SO2 - from five minutes to 24 hours - can harm the human respiratory system and make breathing difficult. Children, the elderly and asthmatics are particularly sensitive to its effects.
The EPA estimated that 2,300 to 5,000 premature deaths and 54,000 asthma attacks will be prevented each year by the new standard. The net benefit of implementing the emissions limit, the EPA estimates, is $36 billion, mostly in medical costs.
"This is real. You can't see sulfur dioxide, but it's a very damaging chemical for public health," Weise said. "This strict standard must be followed."