Cal. Civ. Code § 37.111.1209

(1) Wastewater treatment systems must be located, designed, constructed, and operated in accordance with local and state regulations.
(a) A failed wastewater treatment system must not be used until repaired or replaced. An alternative system approved by the local regulatory authority must be provided during the interim.
(b) All plumbing fixtures must discharge to an approved wastewater treatment system.
(c) Wastewater may not discharge onto the ground surface or to surface water.
(2) An establishment that limits occupancy of individuals to 14 days or less may use an alternative system with applicable approval by the local regulatory authority, Department of Environmental Quality, or department for sewage disposal, provided the system does not place sewage in a location likely to cause pollution of state waters, in violation of Title 75, chapter 5, MCA, or pose potential adverse public health effects.
(3) If the establishment provides individual connections for wastewater disposal:
(a) the sewer riser must be four inches in diameter;
(b) surface drainage must be diverted away from the riser;
(c) if serving a mobile home space, the sewer riser must be located so that connection to the mobile home will approximate a vertical position;
(d) the sewer riser must be separated from the water riser by at least six feet;
(e) the sewer riser must be securely plugged or capped when not in use; and
(f) flex hose may be used to connect an independent or dependent unit if the unit will be connected for less than 30 days. Connections for mobile homes and units that will be connected for more than 30 days must meet state plumbing codes and local wastewater treatment and disposal regulations.