Code Section Group

Water Code - WAT

DIVISION 7. WATER QUALITY [13000 - 16104]

  ( Division 7 repealed and added by Stats. 1969, Ch. 482. )

CHAPTER 4.5. Onsite Sewage Treatment Systems [13290 - 13291.7]
  ( Chapter 4.5 added by Stats. 2000, Ch. 781, Sec. 1. )


For the purposes of this chapter:

(a) “Local agency” means any of the following entities:

(1) A city, county, or city and county.

(2) A special district formed pursuant to general law or special act for the local performance of functions regarding onsite sewage treatment systems within limited boundaries.

(b) “Onsite sewage treatment systems” includes individual disposal systems, community collection and disposal systems, and alternative collection and disposal systems that use subsurface disposal.

(Added by Stats. 2000, Ch. 781, Sec. 1. Effective January 1, 2001.)


(a) On or before January 1, 2004, the state board, in consultation with the State Department of Public Health, the California Coastal Commission, the California Conference of Directors of Environmental Health, counties, cities, and other interested parties, shall adopt regulations or standards for the permitting and operation of all of the following onsite sewage treatment systems in the state and shall apply those regulations or standards commencing six months after their adoptions:

(1) Any system that is constructed or replaced.

(2) Any system that is subject to a major repair.

(3) Any system that pools or discharges to the surface.

(4) Any system that, in the judgment of a regional board or authorized local agency, discharges waste that has the reasonable potential to cause a violation of water quality objectives, or to impair present or future beneficial uses of water, to cause pollution, nuisance, or contamination of the waters of the state.

(b) Regulations or standards adopted pursuant to subdivision (a), shall include, but shall not be limited to, all of the following:

(1) Minimum operating requirements that may include siting, construction, and performance requirements.

(2) Requirements for onsite sewage treatment systems adjacent to impaired waters identified pursuant to subdivision (d) of Section 303 of the Clean Water Act (33 U.S.C. Sec. 1313(d)).

(3) Requirements authorizing a qualified local agency to implement those requirements adopted under this chapter within its jurisdiction if that local agency requests that authorization.

(4) Requirements for corrective action when onsite sewage treatment systems fail to meet the requirements or standards.

(5) Minimum requirements for monitoring used to determine system or systems performance, if applicable.

(6) Exemption criteria to be established by regional boards.

(7) Requirements for determining a system that is subject to a major repair, as provided in paragraph (2) of subdivision (a).

(c) This chapter does not diminish or otherwise affect the authority of a local agency to carry out laws, other than this chapter, that relate to onsite sewage treatment systems.

(d) This chapter does not preempt any regional board or local agency from adopting or retaining standards for onsite sewage treatment systems that are more protective of the public health or the environment than this chapter.

(e) Each regional board shall incorporate the regulations or standards adopted pursuant to subdivisions (a) and (b) into the appropriate regional water quality control plans.

(Amended by Stats. 2010, Ch. 288, Sec. 26. (SB 1169) Effective January 1, 2011.)


It is the intent of the Legislature to assist private property owners with existing systems who incur costs as a result of the implementation of the regulations established under this section by encouraging the state board to make loans under Chapter 6.5 (commencing with Section 13475) to local agencies to assist private property owners whose cost of compliance with these regulations exceeds one-half of one percent of the current assessed value of the property on which the onsite sewage system is located.

(Added by Stats. 2000, Ch. 781, Sec. 1. Effective January 1, 2001.)


Nothing in this chapter shall be construed to limit the land use authority of any city, county, or city and county.

(Added by Stats. 2000, Ch. 781, Sec. 1. Effective January 1, 2001.)

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