An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Summary of Portneuf Valley (Pocatello) PM-10 Maintenance Plan


Portions of Power-Bannock Counties (Pocatello) in Idaho were designated a moderate nonattainment area for PM10 by operation of law upon enactment of the Clean Air Act Amendments of 1990.

On November 5, 1998, EPA granted a request by the State to divide the Power-Bannock counties nonattainment area, which included a portion of the Fort Hall Indian Reservation, into two nonattainment areas; one which included only Reservation lands (Fort Hall nonattainment area) and a second (Portneuf Valley area) under the regulatory jurisdiction of the State.

On June 30, 2004, the State of Idaho submitted a plan that meets the planning obligations for both the nonattainment and maintenance plan. In addition, the State requested redesignation of the Portneuf Valley to attainment for PM10. On May 20, 2005, EPA proposed in the Federal Register to approve the plan and grant the redesignation request. On July 13, 2006, EPA approved the plan and granted the redesignation request. (See 71 FR 39574 (PDF)(6 pp, 161 K,About PDF))

On April 21, 2014, the EPA received Idaho’s SIP revision adjusting the motor vehicle emissions budget in the maintenance plan. On July 17, 2014 the EPA published a direct final rule approving the MVEB. (See 79 FR 41647 (PDF)(3 pp, 240 K)).


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. 


  • City of Pocatello, Residential Wood Combustion Curtailment Ordinance, #2450, January 12, 1994
  • City of Pocatello, Revised Air Quality Curtailment Levels Ordinance, #2726, September 18, 2003
  • City of Chubbuck, Residential Wood Combustion Curtailment Ordinance, #403, November 23, 1993
  • City of Chubbuck, Revised Air Quality Curtailment Levels Ordinance, #582, December 9, 2003


  • Permit # T1-9507-114-1; Facility # 077-00006, J.R. Simpolt Co. April 5, 2004 
  • Compliance Agreement and Voluntary Order, Idaho Code 39-116A, J.R. Simpolt Co, April 16, 2004 

EPA Effective Date

August 14, 2006