Department of
Environmental Quality

The Portneuf Valley PM10 Non-Attainment Area (PVNAA) contains 96.6 square miles of Pocatello, Chubbuck, and surrounding areas. It includes federal land managed by the Bureau of Land Management (BLM) and the Caribou National Forest, as well as privately owned land in the cities of Pocatello and Chubbuck. The combined population of the two cities is approximately 76,000.

The topography of the PVNAA is complex and aids in the formation of strong inversion layers during winter months. This is the period when most of the air pollution events occur.  During these inversions, the major pollutant has been ammonium sulfate, which is formed under high humidity (winter inversions) from the gasses, ammonia and sulfur dioxide.

The PVNAA PM10 SIP was submitted to EPA in 2004. The plan relies on control measures on point and area sources to attain and maintain the National Ambient Air Quality Standards for PM10, primarily measures for control of emissions from residential wood combustion, residential road dust, and the industrial source, J.R. Simplot. In July 2006, EPA approved the plan and granted the redesignation request. As a result, the area has been redesignated a PM10 Maintenance Area. The Portneuf Valley is in attainment for PM2.5 and SO2.

2007

Portneuf Valley Air Toxics Ambient Air Data Evaluation and Health Assessment

2004

Portneuf Valley PM10 Nonattainment Area State Implementation Plan, Maintenance Plan, and Redesignation Request

2001

Eastern Michaud Flats Superfund Site Air Contamination Health Consultation

1999

Portneuf Valley Particulate Matter Air Quality Improvement Plan