Air quality standards exceeded in Garfield County
Glenwood Springs, CO Colorado
GLENWOOD SPRINGS, Colorado ” Recent air monitoring in Garfield County indicated some instances where federal air quality standards were exceeded, county environmental health specialists said Monday.
However, those specialists added that federal requirements dictate that it will take at least three years of data collection to determine if any federal air quality violations occurred. That is because the standards are based on an average over a three-year period, said Jim Rada, environmental health manager for Garfield County.
Ozone monitoring in Rifle, which was conducted from June to September, showed the highest daily level of ozone reached 81 parts per billion (ppb) in July for an eight-hour period ” a figure that is above the federal limit of 75 parts per billion. Monitoring also indicated the fourth highest level of ozone, recorded on July 11 and July 24, reached 74 ppb.
Rada said a federal air quality violation will occur if the average of the fourth-highest-level ozone readings exceed 75 ppb for each year over a three-year period. Rada noted the current rate of ozone emissions on Monday was about 25 ppb.
“That is what we expect during the winter time,” he said, noting ozone emissions are generally highest during the summertime.
Most ozone is created when sunlight interacts with pollutants in the atmosphere and VOCs in motor vehicle exhaust, industrial emissions, gasoline vapors and chemical solvents. Ozone can seriously impair a human’s respiratory system, according to a memo the county environmental specialists supplied to the Garfield County commissioners.
Rada and Paul Reaser, senior environmental health specialist for the county, presented the results of recent air monitoring and the plans to continue it next year to the county commissioners on Monday. They also received approval from the commissioners to put real-time air quality data and other information resources on the Internet ” a resource that will be available soon, they said.
Initial data show average levels of PM2.5 ” a fine particle that comes from vehicle fuel combustion, power plants and industrial processes ” are “comfortably below” federal quality standards of 35 micrograms per cubic meter for a 24-hour period. But some local monitoring, which began in September, has shown some episodes where that limit has been exceeded, Rada said.
“We have to keep that in context,” Rada said. “That is only two months of monitoring.”
As with ozone, Rada added that it will take three years of monitoring to determine if there are any violations of federal air quality standards from PM2.5 emissions.
Recent monitoring of PM10 ” another coarse particle from sources like crushing and grinding operations ” shows levels of that pollutant reached a maximum of 35 micrograms per cubic meter for a 24-hour period in January in Rifle, well below the federal standard of 150 micrograms.
In April, the 24-hour maximum of PM10 in Rifle in July reached about 135 micrograms, but declined to 70 micrograms. In August, September and October, the highest 24-hour maximum level of PM10 in Rifle remained relatively steady at 70 micrograms.
In Parachute, the 24-hour maximum of PM10 reached 20 micrograms in January and rose to about 130 micrograms in April. The 24-hour maximum for PM10 spiked to 210 micrograms in September because of grinding activity near the monitoring site.
“This was a very localized event,” said Reaser. “I want to stress this wasn’t something going on across the entire county.”
The county is also monitoring for volatile organic compounds (VOCs) in Rifle and Parachute, and at two locations south of Rifle and Silt. Some VOCs have hazardous effects on plants, animals and humans and is a precursor to ozone, Reaser said.
Contact Phillip Yates: 384-9117
Post Independent, Glenwood Springs, Colorado CO
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