California Code, Public Resources Code - PRC § 50002

(a) The California Integrated Waste Management Board may, by regulation, specify classifications of solid waste facilities that are exempt from the requirements of Sections 50000, 50000.5, and 50001.  The regulation may be adopted only if the board makes all of the following findings:

(b) The application to land of agricultural products derived from municipal sewage sludge for use as a fertilizer material, based on a finding by the board that the nature of the solid waste poses no significant threat to the public health, the public safety, or the environment, is exempt from the requirements of Sections 50000 and 50000.5.