Changes are coming to a 2004 plan that maintains and monitors air quality in Pocatello and Chubbuck. Those changes will focus on the way emissions from vehicles are measured. The amendment will be made to the State Implementation Plan (SIP) for PM10 (coarse particulate matter) in the Portneuf Valley area.
The amendment addresses only vehicles that travel on paved roads, so other vehicles like ATV's and snowmobiles won't be included. Melissa Gibbs, Airshed Coordinator for the Idaho Department of Environmental Quality, said there are many factors that go into what could affect paved-road vehicles.
"Are we going to have an increase in traffic emissions or are we going to have an increase in the amount of population?" Gibbs said. "So that budget is set so we make sure transportation projects that take place in this valley don't negatively impact air quality."
The budget can also be called a cap, which limits the amount of particle allowed in the air. One of the main particles emitted are PM10 particles. These particles are very small, 1/10 the diameter of a human hair, and they can be a major concern if there are too many particles swirling around in the air.
"The smaller the particle the greater the health concern," Gibbs said. "Those particles can get lodged into deep parts of your lungs, and can't be dislodged by normal means, like coughing."
PM10 particles are released not only by vehicles like cars, but also heavy equipment that may help with road construction. Gibbs said they also work with cities to make sure the gravel and salt mix they put down during winter is a specific kind, as that can release these harmful particles into the air.
Which is why Gibbs said the Idaho DEQ has been working hard since 1996 to make sure the Portneuf Valley stays under that particle cap. Gibbs said before that, Pocatello and Chubbuck historically did not meet the national ambient air quality standard set by the Environmental Protection Agency.
So in order to better measure the particles, the EPA changed the way the particle are measured to be more accurate in 2013. This means the DEQ's plan from 2004 needed to be updated to better reflect the particle amounts.
Gibbs also said she will take your call any time to answer any questions, at 208-236-6160. She also said there is a public comment period open now through March 17.
Gibbs also recommended going to the public informational meeting at 6 p.m. on March 11, 2014 in the City of Pocatello City Council Chambers. The amendment is available for viewing at the Marshall Public Library, 113 S. Garfield Ave. in Pocatello as well as the DEQ Pocatello office, 444 Hospital Way, Suite 300.