NEWPORT — You can breathe easy if you missed last week’s public hearing on a proposal to reclassify the Kalispel Tribe’s airshed under the Clean Air Act.

The U.S. Environmental Protection Agency conducted a public hearing at the Pend Oreille Public Utility District offices on Thursday, although the window to submit written remarks remains open until Friday, Dec. 14, according to EPA.

The tribe submitted a proposal to EPA last year to re-designate the tribe’s reservation as Class I under the Clean Air Act’s significant deterioration program. Located in Usk, the reservation runs along 10 miles of the Pend Oreille River. The boundaries of the reservation lie entirely within the state of Washington.

The federal Clean Air Act’s deterioration prevention program aims to ensure the preservation of air quality where the air is cleaner than national ambient air quality standards. Congress has designated most national parks and wilderness areas as Class I, which allows the least amount of air quality degradation.

The designation is seen by some as a potential bulwark against PacWest Silicon’s smelter proposal south of Newport as emissions from the plant are expected to negatively impact air quality in the region.

County commissioners in Bonner and Boundary counties urged EPA officials to put brakes on the proposal last year because counties were not notified of the tribe’s proposal. They questioned the economic impacts to the local community and the science underpinning the tribe’s proposal.

Bonner County commissioners are scheduled to revisit the issue when they convene at their regular business meeting at 9 a.m. on Tuesday in the Bonner County Administration Building.

The full text of the proposed rule can be viewed at go.usa.gov/xP69s and guidance on effective can be found at epa.gov/dockets/commenting-epa-dockets. Written comments can be directed to regulations.gov and entering in Docket No. EPA-R10-OAR-2017-0347

Keith Kinnaird can be reached by email at kkinnaird@bonnercountydailybee.com and follow him on Twitter @KeithDailyBee.