In 2006, the EPA reduced the 24-hour National Ambient Air Quality Standard (NAAQS) for particulate matter with an aerodynamic diameter of 2.5 µm or less (PM2.5). As a result, Imperial County was designated as a non-attainment area for the 24-hour PM2.5 NAAQS and was required to submit a State Implementation Plan (SIP) to the EPA by December 2012. Due to a court ruling, the final due date for the SIP submittal was pushed back until December 2014.

In order to comply with the non-attainment area designation requirements, Imperial County Air Pollution Control District (ICAPCD) has developed a draft 24-hour PM2.5 SIP. ICAPCD held a preliminary workshop on October 1, 2014 to introduce the SIP and begin receiving public comments. As discussed at the workshop, the SIP has been developed to include the following requirements:

  • Analysis of PM2.5 and PM2.5 precursor concentrations;
  • Best available emission inventory;
  • Emission control strategies to achieve attainment such as “Reasonably Available Control Measures” (RACM) and “Reasonably Available Control Technology” (RACT);
  • Transportation conformity; and
  • Border strategic concepts.

Several existing rules were evaluated, including, but not limited to, architectural coatings, agriculture, asphalt manufacturing, aerospace, solvents and combustion equipment. For more information, please review the Draft 24-hour PM2.5 SIP posted as of October 1, 2014. ICAPCD plans to hold a Public Hearing on November 25, 2014. Please check the ICAPCD website for more information about this event. After the Public Hearing, ICAPCD will consider all final comments before submitting the draft SIP in December 2014.