Ozone readings on Aspen Mountain exceed new federal standards
Glenwood Springs correspondent
Aspen, CO Colorado
GLENWOOD SPRINGS ” Ozone monitoring at several locations in Garfield County and on Aspen Mountain in Pitkin County indicate ozone readings exceed or were close to exceeding new federal air-quality standards set to take effect in May.
Recent sampling atop Aspen Mountain showed the ozone concentration reached a high of 78 parts per billion (ppb) over an eight-hour period. While that level did not exceed the current federal air-quality standard of 84 ppb, the new federal standard will lower that threshold to 75 ppb.
The highest concentration of ozone on Sunlight Mountain outside of Glenwood Springs reached 67 ppb over an eight-hour period. Bell Ranch, near Rifle, saw a high reading of 69 ppb over eight hours, according to the sampling. Testing at Ripple Creek Pass in the White River National Forest yielded a reading of 67 ppb.
“Those numbers seem high for what we expect,” said Andrea Holland-Sears, an air resource specialist with the White River National Forest.
Holland-Sears presented ozone monitoring results from 11 sites in the study, which was conducted in 2006 and 2007, to the Garfield County commissioners on Monday. The purpose of the study was to assess future ozone trends and determine locations for long-term ozone monitoring.
In the Earth’s lower atmosphere, ground-level ozone is considered “bad” ” it is a pollutant that can pose a significant health risk, especially for children with asthma, according to the Environmental Protection Agency. Ozone can also damage crops, trees and other vegetation, and it is a main ingredient of urban smog.
Motor vehicle exhaust and industrial emissions, gasoline vapors and chemical solvents, as well as natural sources, emit nitrogen and volatile organic compounds that help form ozone, according to the EPA.
All the high-ozone concentrations in Holland-Sears’ sampling came during the summer months ” the only time ozone was sampled. Ozone data presented by Holland-Sears showed that higher altitudes generally had greater concentrations of ozone, except for the Bell Ranch site, which is near natural gas facilities. The elevation of the Bell Ranch site was about 5,800 feet.
“The numbers at Bell Ranch seemed rather high considering its elevation,” Holland-Sears said.
Holland-Sears said future goals for the monitoring program include gathering ozone data during the winter months, particularly in light of high readings in the Pinedale area of Wyoming, which is undergoing rapid development by the oil and gas industry. Earlier this month, the Wyoming Department of Environmental Quality recently issued three ozone advisories for the area.