The Northern Sierra Air Management District was formed in 1986 by the merging of the Air Pollution Control Districts of Nevada, Plumas and Sierra Counties. The District is required by state law to achieve and maintain the federal and state Ambient Air Quality Standards, which are air quality standards set at levels that will protect the public health. The District is composed of three primary entities, each with a specific purpose: District staff , Governing Board of Directors, and Hearing Board.