Another inversion winter will trigger air quality review, official says
Wintertime inversions are an annoyance for many chilly Grand Junction residents.
They could become something more serious for the city in coming years, according to Gordon Pierce, program manager with the Air Pollution Control Division of the Colorado Department of Public Health and Environment.
Inversions, when warmer air above the valley holds in colder air and pollution at lower elevations, can hold in certain particles from sources such as diesel exhaust, wood-burning stoves, industrial activity, dust, fertilizer, animal waste and sewage. Grand Junction is one inversion-filled year away from being in violation of Particulate National Ambient Air Quality Standards for particles from these sources.
The air-quality standards use a three-year average for measurements. The city has had particulate values above the standard level for fine particulate matter in 2009 and in the first half of this year.
“The winters the past two years have had some pretty deep inversions,” Pierce said, adding the inversions coincided with population fluctuations, more vehicle miles traveled statewide and continued operations at the coal-fired Cameo power plant.
Consequences won’t be swift if Grand Junction records another year of high levels, Pierce said. The Colorado Department of Public Health and Environment has a year to report a violation to the Environmental Protection Agency. The agency has a year after that to report back to the department, plus another three years to approve an implementation plan for lowering the levels. How much time the department has to implement the plan, which could ask businesses and residents to modify behavior to reduce exhaust, smoke or dust production, depends on whether the violation is deemed severe, moderate or marginal, Pierce said.
Pierce said it has been about 10 years since a Colorado community was found in violation of national air-quality standards.