Cal. Code Regs. tit. 14 § 1935
All wells shall be cased in such a manner as to protect or minimize damage to the environment, usable ground waters and surface waters (if any), geothermal resources, life, health and property. The permanent wellhead completion equipment shall be attached to the production casing or to the intermediate casing if production casing does not reach to the surface.
Division specifications for casing strings shall be determined on a well-to-well basis. All casing strings reaching the surface shall provide adequate anchorage for blowout-prevention equipment, hole pressure control and protection for all natural resources. The following casing requirements are general but should be used as guidelines in submitting proposals to drill.
Cal. Code Regs. Tit. 14, § 1935