Napa County Municipal Code Ch. 13.16 General Provisions and Definitions

A. Chapters 13.16 through 13.56 are intended to regulate individual, private and public sewage systems with a maximum daily flow of less than five thousand gallons per day within the unincorporated portions of the county. Larger systems are regulated by the applicable Regional Water Quality Control Board.

B. The definitions in Chapter 2 of the 2007 Edition of the California Plumbing Code (CPC) apply herein by reference where unchanged, and are referenced as e.g. "(CPC § 202.0)." If the CPC definition has been modified, it is indicated as e.g. "(CPC § 202.0, modified)."

C. Where non-substantive changes are made in this chapter to other referenced CPC provisions or where the only substantive changes in this chapter are modifications of this code to conform to the CPC, then the CPC section, table number, or appendix is noted at the end of the section. Where substantive modifications have been made from the CPC provision, then the CPC section, table number, or appendix is noted at the end of the section followed by the word "modified."

(Ord. No. 1337, § 1, 5-5-2010; Ord. 1109 § 1 (part), 1996)

"Abutting lot" means a lot or parcel of land which wholly or in part lies on the other side of a common boundary with the parcel in question.

(Ord. 1109 § 1 (part), 1996)

The term "administrative authority" means the county director of planning, building, and environmental services or the director's designees.

(Ord. 1109 § 1 (part), 1996)

(Ord. No. 1374, § 25, 9-11-2012)

"Alternative sewage treatment system" means a sewage disposal system that uses an advanced method of effluent treatment and/or distribution and is designed by a licensed Civil Engineer or Environmental Health Specialist registered in the state of California. An alternative sewage treatment system is designed to mitigate soil and/or groundwater conditions that render a lot inappropriate for a conventional septic system, or to mitigate severely inadequate expansion area for repair or replacement of an existing, improperly functioning onsite sewage disposal system. An alternative sewage treatment system does not include a conventional system that only uses a pump to deliver effluent to a non-pressurized dispersal field complying with all surface and subsurface setback requirements.

(Ord. No. 1337, § 2, 5-5-2010)

"Approved" means accepted or acceptable under an applicable specification or standard stated or cited in this code, or accepted as suitable for the proposed use under procedures and authority of the administrative authority (CPC § 202.0, modified).

(Ord. No. 1337, § 3, 5-5-2010; Ord. 1109 § 1 (part), 1996)

"Approved sewage disposal system" means any sewage disposal system, individual, private or public, which is accepted or acceptable under an applicable specification or standard stated or cited in Division II of this title, or in state law, or accepted as suitable for the proposed use under procedures and authority of the administrative authority.

(Ord. 1109 § 1 (part), 1996)

"Building drain" means that part of the lowest piping of a drainage system which receives the discharge from soil, waste and other drainage pipes inside the walls of the building and conveys it to the building sewer beginning two feet (0.6m) outside the building wall (CPC § 202.0).

(Ord. 1109 § 1 (part), 1996)

"Building sewer" means that part of the horizontal piping of a drainage system which extends from the end of the building drain and which receives the discharge of the building drain and conveys it to a public sewer, private sewer, individual sewage disposal system or other point of disposal (CPC § 202.0).

(Ord. 1109 § 1 (part), 1996)

"Cleanout" means a fitting inserted in a pipe system, fitted with a removable plug, whereby access to the pipe is obtained for purposes of cleaning or unstopping.

(Ord. 1109 § 1 (part), 1996)

"Conventional sewage disposal system" means a sewage disposal system that has adequate soil and site conditions to support a system that uses a septic tank and gravity to disperse effluent throughout the disposal leach field, and in which no pretreatment device is utilized or requires design by a qualified professional. This term includes systems that use a pump to transport effluent received from the septic tank to an uphill disposal field where the effluent is then dispersed by gravity into an approved leach field placed in an area with surface and subsurface features complying with the standards in this division.

(Ord. No. 1337, § 4, 5-5-2010)

"Disposal system" means those works, and appurtenances thereto, which are designed to collect, treat and dispose of liquid wastes generated by humans, animals, or industrial processes from dwellings, business, commercial, industrial establishments or agricultural pursuits.

(Ord. 1109 § 1 (part), 1996)

"Disposal system reserve area" means that area on a lot or parcel which is set aside for the installation of the disposal system, together with such area set aside for expansion of the system in the event of a failure or near failure of the original sewage system installation.

(Ord. 1109 § 1 (part), 1996)

"Distribution box" means a watertight structure which receives effluent from the septic tank and distributes it to two or more header pipes and leach lines. Minimum size of a distribution box shall be twelve inches inside diameter; box shall be constructed of Class A concrete; the minimum thickness of sides, bottom and cover shall be two inches; other materials may be approved by the administrative authority.

(Ord. 1109 § 1 (part), 1996)

The term "division" shall mean this Division II entitled "Sewage Systems" of Title 13 of the Napa County Code, Chapters 13.16 through 13.56, inclusive.

(Ord. No. 1337, § 5, 5-5-2010)

"Drainfield" means that area wherein percolation and transpiration of sewage takes place which includes the leaching lines.

(Ord. 1109 § 1 (part), 1996)

"Effective sidewall area" means that portion of the sidewalls of a leaching trench extending upward from the bottom to a point six inches above the invert of the perforated pipe installed in the leaching trench.

(Ord. 1109 § 1 (part), 1996)

See "alternative sewage treatment system."

(Ord. No. 1337, § 6, 5-5-2010; Ord. 1109 § 1 (part), 1996)

"Equal distribution" means a means of sewage effluent disposal which may be used on level or near level ground which channels all flow into leaching trenches which are connected in such a manner that all trenches receive an equivalent volume of water.

(Ord. 1109 § 1 (part), 1996)

"Expansion area" means the area which is held in reserve and to be kept unencumbered in order to provide a place for additional leaching lines or plant capacity in the event of need.

(Ord. 1109 § 1 (part), 1996)

"Failure" means a condition of an on-site sewage system that threatens the public health by inadequately treating sewage or by creating a potential for direct or indirect contact between sewage and the public. Examples of failure include:

A. Sewage on the surface of the ground;

B. Sewage backing up into a structure caused by slow soil absorption of septic tank effluent;

C. Sewage leaking from a septic tank, pump chamber, holding tank, or collection system;

D. Cesspools or seepage pits where evidence of ground water or surface water quality degradation exists;

E. Inadequately treated effluent contaminating ground water or surface water;

F. Noncompliance with permit conditions.

(Ord. No. 1337, § 7, 5-5-2010)

"Field textural analysis" means an evaluation of backhoe excavation holes which have been dug by an approved percolation tester and entails a structural, textural and visual evaluation of soil properties.

(Ord. 1109 § 1 (part), 1996)

"Fixture unit" means a quantity in terms of which the load producing effects on the plumbing system of different kinds of plumbing fixtures are expressed on some arbitrarily chosen scale (CPC § 202.0).

(Ord. 1109 § 1 (part), 1996)

"Grease interceptor" means a watertight tank with a minimum capacity of seven hundred fifty gallon (2839 L), having at least two compartments, designed and installed so as to intercept nonpetroleum fats, oil, and grease (FOG) from the wastewater discharge (CPC § 202.0, modified).

(Ord. No. 1337, § 8, 5-5-2010; Ord. 1109 § 1 (part), 1996)

"Header pipe" means the solid line which receives effluent from the distribution box and conveys it to the disposal area. Header pipes shall be no less than five feet, shall be constructed of materials approved for use in the building and shall be laid on natural soil.

(Ord. 1109 § 1 (part), 1996)

The term "hold and haul system" means a collection, storage and off-site disposal system for non-sanitary sewage that is an alternative to onsite treatment and disposal or connection to an approved public or private sewer where the holding tank or tanks are the primary means of wastewater management.

(Ord. No. 1374, § 26, 9-11-2012)

The term "holding tank" means a watertight receptacle designed to receive and store sewage for offsite hauling to an approved disposal facility serving lowflow (less than one hundred gallons per day), non-residential facilities where no onsite alternative is available.

(Ord. 1109 § 1 (part), 1996)

(Ord. No. 1374, § 27, 9-11-2012)

For "house sewer" see "building sewer," Section 13.16.070 of this chapter.

(Ord. 1109 § 1 (part), 1996)

"Individual sewage disposal system" means a septic tank with the effluent discharging into a subsurface drainfield or such other facilities as may be permitted under this code which serves:

1. A single-family dwelling;

2. A two family dwelling (duplex); or

3. Commercial uses which do not exceed a sewage flow of one thousand five hundred gallons per day.

(Ord. 1109 § 1 (part), 1996)

See "sewage," Section 13.16.360 of this chapter.

(Ord. 1109 § 1 (part), 1996)

"Invert" means the lowest inside portion of the cross-section of a pipe.

(Ord. 1109 § 1 (part), 1996)

"Leaching lines" means those rock filled trenches designed to accept septic tank effluent, discharged from perforated pipes laid in the trenches.

(Ord. 1109 § 1 (part), 1996)

"Lot" shall be as defined in Section 17.02.320 of this code.

(Ord. 1109 § 1 (part), 1996)

"Minor, limited or temporary use" means those uses which, as determined by the administrative authority, are of a lesser nature in extent or duration of use, and not intended for permanency.

(Ord. 1109 § 1 (part), 1996)

"Parcel" shall be as defined in Section 17.02.320 of this code.

(Ord. 1109 § 1 (part), 1996)

"Perched water table" means water, surface and/or subsurface, which accumulates on or in the upper strata of soil or subsoil due to an impervious layer beneath.

(Ord. 1109 § 1 (part), 1996)

"Percolation test" means a means of determining the ability of soil to absorb liquid. Such tests are to be made only by persons approved by the administrative authority conducted in accordance with Section 13.28.030, and reviewed and approved by the administrative authority.

(Ord. 1109 § 1 (part), 1996)

"Plumbing fixture" means approved-type installed receptacles, devices or appliances which are supplied with water or which receive liquid or liquid-borne wastes and discharge such wastes into the drainage system to which they may be directly or indirectly connected. Industrial or commercial tanks, vats and similar processing equipment are not plumbing fixtures, but may be connected to or discharged into approved traps or plumbing fixtures when and as otherwise provided for elsewhere herein (CPC § 202.0).

(Ord. 1109 § 1 (part), 1996)

"Potential bedroom" means any room with a floor area equal to or greater than seventy square feet, including lofts, sewing rooms, offices, game rooms, etc., that meets building codes for a sleeping room. A closet or lack thereof is not used in determining whether a room is a bedroom.

(Ord. 1109 § 1 (part), 1996)

"Private sewer" means a building sewer which receives the discharge from one or more building drains and conveys it to a public sewer, individual sewage disposal system, private sewage disposal system, or other point of disposal (CPC § 202.0, modified).

(Ord. 1109 § 1 (part), 1996)

"Private sewage disposal system" means a septic tank with the effluent discharging into a subsurface disposal field or such other facilities as may be permitted under this code which serves any uses other than those served by an individual sewage disposal system (CPC § 202.0, modified).

(Ord. 1109 § 1 (part), 1996)

"Public sewer" means a common sewer directly owned, controlled, and/or maintained by a public entity including but not limited to a municipality or special district (CPC § 202.0, modified).

(Ord. 1109 § 1 (part), 1996)

"Public sewage disposal system" means any publicly-owned, controlled and/or maintained system which collects, treats, and disposes by surface or subsurface means sewage collected from public or private sewers which is not disposed of in an individual or private sewage disposal system.

(Ord. 1109 § 1 (part), 1996)

The term "qualified professional" means a licensed Civil Engineer (including Engineer-in-Training under the direction of a licensed Civil Engineer), Geologist, Registered Environmental Health Specialist, or Soil Scientist. Civil Engineers, Registered Environmental Health Specialists and Geologists must show proof of registration or licensing in the state of California. Soil Scientists must show proof of registration in any state in the United States.

(Ord. No. 1337, § 9, 5-5-2010)

The term "service provider" means a licensed Civil Engineer, Registered Environmental Health Specialist, or any person who is licensed as a "certified on-site wastewater system inspector" or other equivalent license by passing a state or nationally accredited onsite wastewater exam.

(Ord. No. 1337, § 10, 5-5-2010)

"Sewage" means any liquid waste containing animal or vegetable matter or chemicals in suspension or solution, including industrial and agricultural as well as domestic liquid wastes (CPC § 202.0, modified).

(Ord. 1109 § 1 (part), 1996)

"Sewage entity" means a municipality, special district or private organization which deals in the collection, treatment or disposal of sewage.

(Ord. 1109 § 1 (part), 1996)

"Serial distribution" means a means of sewage effluent disposal which channels all flow into a series of leaching trenches, which are connected one after the other in such a manner that the first must fill before overflowing into the second, etc.

(Ord. 1109 § 1 (part), 1996)

"Site evaluation" means a means of evaluating a parcel for its ability to provide an adequate sewage disposal system. A site evaluation includes a field textural analysis of soil texture, structure, and related variables such as depth to water table, soil pores, root depth and soil type to determine the percolation range at the sidewall of the proposed trench. Site evaluations are to be made by persons certified by the administrative authority and in accordance with Section 13.28.020.

(Ord. 1109 § 1 (part), 1996)

"Soil pipe" means any pipe which conveys the discharge of water closets, urinals or fixtures having similar functions, with or without the discharge from other fixtures, to the building drain or building sewer (CPC § 202.0).

(Ord. 1109 § 1 (part), 1996)

Editor's note— Ord. No. 1337, § 11, adopted May 5, 2010, repealed § 13.16.410, which pertained to special design sewage disposal system. See also the Code Comparative Table and Disposition List.

"Subdivision" shall be as defined in 17.02.530 of this code.

(Ord. 1109 § 1 (part), 1996)

"Stabilized percolation rate" means the percolation rate at the end of the percolation test which is shown to be consistent. For soil one inch per hour or greater, consistent shall mean readings within one-quarter of an inch per hour; for soil less than one inch per hour, consistent shall mean readings within one-eighth of an inch per hour.

(Ord. 1109 § 1 (part), 1996)

"Urbanizing area" means any area characteristic of, constituting or pertaining to a city, town or other municipality or densely populated area, together with outlying parts of the area adjacent to, on the outskirts of or surrounding the city, town or municipality or densely populated area, including the rural periphery or environs, which form an economic and socially related region, taking into consideration such factors as present and future population trends and patterns of urban growth, location of transportation facilities and systems, geographical factors affecting the location of utility systems, and distribution of industrial, commercial, residential, governmental, institutional and related activities and services.

(Ord. 1109 § 1 (part), 1996)

It shall be unlawful and a public nuisance to construct, operate, or maintain any private sewer, individual sewage disposal system, private sewage disposal system, special design sewage disposal system, or appurtenances thereto in violation of any of the provisions of this division, or to construct or to fail to properly abandon when ordered any cesspool or seepage pit as defined in the California Plumbing Code. In addition to any other remedies provided in this division, such violations may be abated pursuant to Chapter 1.20 and shall be a misdemeanor punishable as provided in Section 1.20.150 of this code (CPC § 722.4, modified).

(Ord. 1297 § 4, 2007: Ord. 1109 § 1 (part), 1996)