California Code, Public Resources Code - PRC § 30418

(a) Pursuant to Division 3 (commencing with Section 3000), the Geologic Energy Management Division of the Department of Conservation is the principal state agency responsible for regulating the drilling, operation, maintenance, and abandonment of all oil, gas, and geothermal wells in the state. Neither the commission, local government, port governing body, or special district shall establish or impose such regulatory controls that duplicate or exceed controls established by the Geologic Energy Management Division pursuant to specific statutory requirements or authorization.

This section shall not be construed to limit in any way, except as specifically provided, the regulatory controls over oil and gas development pursuant to Chapters 7 (commencing with Section 30600) and 8 (commencing with Section 30700).

(b) The Geologic Energy Management Division of the Department of Conservation shall cooperate with the commission by providing necessary data and technical expertise regarding proposed well operations within the coastal zone.