Existing law designates air pollution control districts and air quality management districts as having the primary responsibility for the control of air pollution from all sources other than vehicular sources, and, subject to the powers and duties of the State Air Resources Board, requires that air districts adopt and enforce rules and regulations to achieve and maintain the state and federal ambient air quality standards in all areas affected by emission sources under their jurisdiction.

Existing law requires the board of each air district to establish by regulation a system by which all reductions in the emission of air contaminants that are to be used to offset certain future increases in the emission of air contaminants be banked as credits prior to use to offset future increases in emissions, except as specified.