California has 35 local Air Districts regulated by the California Air Resources Board which are responsible for regional air quality planning, monitoring, and facility permitting. The districts issue legislation and administer air quality improvement programs. These Air Quality Management Districts, or AQMD's, are the California Air Resources Board's primary partners in ensuring clean air across the state of California.
These 35 Air Districts are responsible for "addressing emissions from stationary sources through permits and local rules." Each district regulates air quality control for the public's health and welfare, passing regulations and laws to strengthen the state's fight against air pollution.
For example, Section 42451.5 was added to the Health and Safety Code which "gives pollution control officers the power to issue immediate orders on or after January 1, 2018, to stop non-vehicular polluting operations when violations pose an 'imminent and substantial danger."