Northern Idaho Air Quality Plans & Reports
The Coeur d’Alene Region covers five northern Idaho counties, and while most areas meet national air quality standards, some locations reveal levels of concern.
The improper use of wood burning stoves in the winter has contributed substantially to increased concentrations of fine (PM2.5) particulate matter in the atmosphere, especially during periods when surface level inversions build and trap smoke near the ground. Places like the city of Pinehurst and surrounding areas of Shoshone County have experienced PM2.5 air pollution levels that caused the area to be designated as nonattainment, an EPA classification. Advancement in wood stove technology as well as DEQ education and outreach activities are helping to reduce emissions in these areas.
The Greater Sandpoint Area has a history of coarse particulate (PM10) air pollution. In 1997, the area was designated by EPA as nonattainment for PM10 due to violations of federal air quality standards for this pollutant. Since 1997, however, significant improvements in air quality have been realized thanks to the efforts of the community. In December 2011, DEQ submitted a PM10 Limited Maintenance Plan and Redesignation Request to EPA to redesignate the area to attainment status. The plan focuses on a comprehensive residential wood combustion program, controls on fugitive road dust, and emission limitations on industrial sources. In April 2013, EPA approved in part and disapproved in part the Sandpoint PM10 Limited Maintenance Plan and redesignated the Sandpoint area to attainment for PM10.
Other factors that impact air quality in this region are the burning of land clearing debris and open backyard burning during the fall and spring months, as well as slash and agricultural burning.
A stringent air quality permit program limits emissions for large stationary sources or facilities to levels below what would be considered harmful to citizens and the environment. Growth in this sector over recent years has not been significant. Smaller facilities, or “area sources,” complete the picture of emissions from businesses. These emissions, though minimal and considered below regulatory concern in most instances, have yet to be inventoried fully.
At this time, very little evaluation of secondary air pollutants has been undertaken with the exception of ground-level ozone on the Rathdrum Prairie. Secondary pollutants are formed when different compounds present in the atmosphere react with each other. For example, ozone forms when organic hydrocarbons bond with nitrogen oxides to produce ozone during periods of strong sunlight. The importance of understanding the chemical makeup of the local airshed is critical in evaluating several issues including potentially harmful depositional impacts on residents, local surface water bodies, and crops. This issue becomes increasingly important as population grows and automobile and stationary source emissions continue to increase both in Idaho and Washington.
North Idaho Air Quality Summary Reports