California Code, Public Resources Code - PRC § 3757.1

Notwithstanding any other provisions of this chapter, where a parcel of land contains one acre or more and all or substantially all of the surface is unavailable for the location of a geothermal well and directional drilling is found by the supervisor to be necessary, the supervisor may approve proposals to drill wells at whatever locations the supervisor determines to be advisable for the purpose of properly developing the geothermal resources except, that no well shall be drilled or permitted to produce which is located within 25 feet of the outer boundary of the parcel of land on which the well is situated or within 25 feet of a public road, street, or highway dedicated prior to the commencement of drilling. The supervisor may require, at the time the supervisor gives approval of the notice of intention to drill, redrill, or deepen such well, that a subsurface directional survey be made, and that the survey be filed with the supervisor within 15 days of cessation of drilling operations.