Spokane officials thought the city had flunked the federal carbon monoxide standard only once in 1996.
It turns out Spokane flunked twice. That’s bad news, because the federal Clean Air Act allows only one violation per year and the city could face sanctions for non-compliance.
The second violation was announced Tuesday by the Spokane County Air Pollution Control Authority.
It didn’t occur at a controversial monitor near Empire Ford on Third Avenue that had registered a violation of the federal standard last Feb. 12. The Spokane Chamber of Commerce has challenged that location because of the traffic congestion there.
The second violation occurred Dec. 30 at Hamilton and Sharp in the Gonzaga University neighborhood.
That monitor registered 10 parts per million averaged over eight hours - above the U.S. Environmental Protection Agency’s 9 parts per million safety standard for the colorless, odorless gas.
“On Dec. 30, pollution levels began to rise in the early afternoon and continued to rise during the commute home when carbon monoxide pollution peaked around 6 p.m.,” said Ron Edgar, technical services chief for the air quality agency.
The streets were clogged with slushy snow, which narrowed driving lanes and slowed traffic, Edgar said.
“It only takes a couple miles per hour decrease in traffic flow to substantially increase CO levels,” Edgar said.