Health & Saf. Code, § 40715

(a) Every district shall establish and implement supplemental toxic air contaminant monitoring networks to supplement the existing monitoring capacity of the board and the districts as specified in the guidelines developed by the state board pursuant to Section 39668. The district may establish a schedule of fees to be paid to the district by sources of toxic air contaminants within the district which shall not exceed 50 percent of the costs of establishing and implementing these monitoring networks. Funds for the remaining 50 percent of the costs of establishing and implementing the supplemental toxic air contaminant monitoring networks shall be provided by the state board pursuant to subdivision (c) of Section 39668. Districts shall not be required to expend any district funds to establish and implement the supplemental toxic air contaminant monitoring program, as determined by Section 39668, that are in excess of the amount of state funds provided by the state board for that purpose.

(b) It is the intent of the Legislature that this district supplemental toxic air contaminant monitoring program shall supplement existing laws and regulations to protect human health and safety from the adverse effects of toxic air contaminants and shall not limit the existing authority of any state or local agency to identify or control toxic air contaminants.