California Code, Health and Safety Code - HSC § 41750

(a) Existing law authorizes each district to impose separate and sometimes inconsistent emission control requirements for, and to require separate permits to operate, portable equipment that are used at various sites throughout the state.

(b) That multiplicity of permits and regulatory requirements imposes a complex and costly burden on California businesses that use, hire, provide, and manufacture that equipment.

(c) A uniform, voluntary system of statewide registration and regulation of portable equipment, consistent with current state and federal air quality law, is necessary to ensure consistent and reasonable regulation of that equipment without undue burden on their owners, operators, and manufacturers.

(d) Portable equipment has attributes of both mobile sources and stationary sources of air pollution. A separate registration and emission control program is needed to reflect the unique operating characteristics of that equipment while providing authority for a statewide program of emission reduction measures to be applied to existing in-state, out-of-state, and newly manufactured portable equipment.