California Code, Health and Safety Code - HSC § 25289

(a) To carry out the purposes of this chapter or Chapter 6.75 (commencing with Section 25299.10), any duly authorized representative of the local agency, the regional board, or the board has the authority specified in Section 25185, with respect to any place where underground tank systems are located, or in which records relevant to operation of an underground tank system are kept, and in Section 25185.5, with respect to real property which is within 2,000 feet of any place where underground tank systems are located. The authority conferred by this subdivision includes the authority to conduct any monitoring or testing of an underground tank system.

(b) To carry out the purposes of this chapter or Chapter 6.75 (commencing with Section 25299.10), any authorized representative of the local agency, the regional board, or the board may require the owner or operator of an underground storage tank to, upon request, submit any information relevant to the compliance with this chapter or the regulations, to conduct monitoring or testing, and to report the results of that monitoring or testing under penalty of perjury. The burden of the monitoring, testing, and reporting, including costs, shall bear a reasonable relationship to the need for the monitoring, testing, and reporting.