If you plan to install or operate any kind of diesel fired stationary or portable engine greater than 50 horsepower within the 3 counties of this Air District, then you will need to obtain an Air Pollution permit.  If you plan to install or operate any kind of stationary or portable engine that does NOT use diesel, then PLEASE call the Air District and speak with one of our permitting specialists. Visit our Forms page to download the forms: (1) Instructions for Permit Applications, (2) Permit Application Form, and (3) Internal Combustion Engine Supplemental Form. 

Emergency Generator Reference: A quick and simple PDF that summarizes generator district regulation. 

Northern Sierra Emergency Generator Handout