DURANGO Members of the Colorado Air Quality Control Commission, meeting in Durango this week, were briefed Thursday about the possibility that Southwest Colorado could be in violation of the new national ozone standard.
A decline in ozone readings in the Southwest Colorado airshed in recent years could be the result of reduced emissions, Mike Silverstein told board members.
But it could be a new ballgame when the Environmental Protection Agency publishes its new ozone standard at the end of July, Silverstein said.
Silverstein is the manager of planning and policy at the Air Pollution Control Division of the Colorado Department of Public Health and Environment.
In the atmosphere, ozone protects the Earth against ultraviolet radiation. But on the ground ozone formed by the reaction of sunlight on pollutants such as nitrous oxide and volatile organic compounds is a colorless, toxic gas that carries serious health complications.
The current EPA standard for ozone is 75 parts per billion by volume. Silverstein said the new benchmark could range from 60 ppb to 70 ppb.
If the standard is around 70 ppb, the only area in Colorado that would fall into nonattainment status would be the Denver metropolitan area, Silverstein said.
Anything below 70 ppb could affect the San Juan Basin (the Durango/Farmington axis, including the Southern Ute Indian Tribe reservation), Silverstein said.
He estimated ozone readings in the basin range to be from 50 ppb to 69 ppb.
A study by the Colorado Department of Public Health and Environment and the New Mexico Environment Department presented Thursday concluded that in view of a possible nonattainment rating, the Four Corners will require aggressive action to protect human health and the environment.
Commissioners heard a report on the Durango & Silverton Narrow Gauge Railroad, which has received its share of attention for its coal-generated smoke.
Laura Lewis Marchino, a member of a task force working to reduce train smoke, said the group is looking for $1.2 million to expand the scrubber system that removes smoke from locomotives idling overnight.
The train isnt a major source of emissions, but its identifiable, said Lewis Marchino, who added that the amount of emissions has never been quantified.
The only public comment was taken Wednesday after the Air Pollution Control Division described its monitoring of ozone and other pollutants, particulate matter and visibility in Southwest Colorado.
The conclusion: Air quality is very good overall, and there are no violations of federal health standards.
Representatives of La Plata County and the Mountain Studies Institute spoke about county measures to reduce energy use, monitoring mercury deposition at Molas Pass and Mesa Verde National Park and taking core samples in alpine lakes.
About 10 individuals commented on a range of issues.
All wanted regulators to tighten the screws on the coal-fired Four Corners Power Plant and the San Juan Generating Station in northwest New Mexico one of the dirtiest power plants in the country from which haze reaches Colorado.
They decried the lack of controls on emission-spewing gas dehydrators and compressor stations; said the Colorado Department of Public Health and Environment must get a jump on plans to exploit shale deposits; and asked the commission to improve information sharing with the public.
Dan Randolph, acting director of the San Juan Citizens Alliance, said voluntary compliance with regulations doesnt work. Regulatory teeth do, he said.
Jennifer Thurston with the Sheep Mountain Alliance urged the Air Pollution Control Division to look sharply at the request for an air permit requested by a uranium mill in the Paradox Valley.
The alliance, dedicated to preserving the natural environment in the Telluride area, is locked in a lawsuit that asks the state to revoke the uranium mills license, which was issued in January.
