California Air Resources Board

This page contains information regarding recent and historical State Implementation Plan (SIP) activity related to Plumas County-City of Portola, a nonattainment area for the PM2.5 National Ambient Air Quality Standard under the jurisdiction of the Northern Sierra Air Quality Management District.

• Portola PM2.5 State Implementation Plan
• Wood Stove Change-Out Program for Greater Portola Nonattainment Area and Progress Reports

Recent and historical SIP activity related to the Imperial County Air Pollution Control District.

• 2018 Imperial County PM10 State Implementation Plan
• 2018 State Implementation Plan for the 12 µg/m3 PM2.5 Annual Standard
• 2017 State Implementation Plan for the 75 ppb 8-hour Ozone Standard
• 2013 State Implementation Plan for the 2006 24-hour PM2.5 Moderate Nonattainment Area
• 2009 1997 8-hour Ozone Modified Air Quality Management Plan and Reasonably Available Control Technology SIP
• 2009 Imperial County PM10 State Implementation Plan
• February 2008 Ozone Early Progress Plans