Solano County Municipal Code Art. IX Definitions

(a) The definitions contained in this section shall only apply to this Chapter.

(b) The following words and phrases, whenever used in this Chapter, shall have the meaning hereafter defined:

(1) Abandoned On-Site Sewage Disposal System - A cesspool, septic tank, holding tank, pit privy, dosing tank, or interceptor that is no longer used, or that is not connected to a structure or building drain, or that receives no wastewater and has not been destroyed in a manner approved by the Environmental Health Services Division.

(2) Alternative System - A sewage disposal system that uses an advanced method of effluent treatment and/or distribution and is designed by a Civil Engineer, Certified Engineering Geologist or Environmental Health Specialist registered in the State of California. An alternative system is designed to mitigate soil and/or groundwater conditions which render a lot inappropriate for a standard septic system, or to mitigate severely inadequate replacement area for repair or replacement of an existing, improperly functioning on-site sewage disposal system. An alternative system does not include a standard system that only uses a pump to deliver effluent to a non-pressurized disposal field complying with all surface and subsurface set back requirements.

(3) Approved On-Site Sewage Disposal System - is a system for which an approved final permit is on file with the Environmental Health Services Division and for which the conditions upon which the permit was approved have not changed.

(4) ASTM - American Society for Testing Materials.

(5) Bedrock - Solid rock, which may have fractures, and that lies beneath soils or other unconsolidated material. Material is considered to be rock when over fifty (50%) percent by volume is composed of coarse fragments that are retained on a #10 sieve.

(6) Bedroom - Any room that can be used for sleeping purposes. For purposes of sizing the on-site sewage disposal system, habitable rooms with a floor area equal to or greater than 70 square feet and designed to provide privacy to the occupant will typically be considered bedrooms. Such rooms include, but are not limited to, those designated on plans as bedrooms, lofts, sewing rooms, dens, offices, and game rooms. A closet, or lack thereof, shall not determine whether a room is considered a bedroom. Kitchens, bathrooms, laundry rooms, rooms with large entry ways lacking doors and designed that the installation of a door would require a building permit, rooms with a fuel-burning water heater, and rooms not meeting the Uniform Housing Code as approved by Solano County requirements for a bedroom may not be considered bedrooms at the discretion of the Environmental Health Services Division.

(7) Bulk Density - The mass of dry soil per unit of bulk volume.

(8) Building Sewer - The solid pipe connecting the building drain to a septic tank, interceptor, or sanitary sewer.

(9) Cesspool - A lined or unlined excavation in the ground that receives wastewater, allows the separation of solids and liquids, retains the solids and allows liquids to seep into the surrounding soil.

(10) Chemical Toilet - A non-flushing, non-recirculating toilet facility wherein waste is deposited directly into a chamber that may contain a solution of water and chemicals.

(11) Cleanout - A fitting inserted into a piping system, with a removable plug whereby access to the pipe is obtained for the purposes of cleaning or unstopping.

(12) Coarse Fragments - Rock or consolidated mineral particles greater than 2.00 mm in diameter.

(13) Community Sewage Disposal System - a system that accepts sewage from two or more separate lots. Includes public sewer and community on-site sewage disposal system.

(14) Construction permit: Gives approval for specific on-site sewage disposal system work as detailed and conditioned in the construction permit and these standards.

(15) Cumulative impacts - The persistent and/or increasing effects of on-site sewage disposal systems resulting from the density of the discharges from such systems in relation to the assimilative capacity of the ground environment. Examples include salt or nitrate additions to groundwater, nutrient enrichment of surface water, and hydraulic interference both with groundwater and between adjacent on-site sewage disposal systems.

(16) Cutbank - Any naturally occurring or man-made slope that has greater than 30 percent slope and extends vertically at least 3 feet from the toe of the slope to the top of the slope. Includes cuts supported by retaining walls.

(17) Disposal Field - The portion of the on-site sewage disposal system and the surrounding area used for dispersion of the liquid portion of wastewater into the soil. Consists of one or more leachlines or other methods approved by the Environmental Health Services Division for wastewater dispersion.

(18) Distribution Box - A watertight structure that receives effluent from the septic tank and distributes it to two or more header pipes to the disposal field.

(19) Diversion Valve - A device that receives wastewater through one inlet and distributes it to two (2) or more outlets, only one of which is used at a given time.

(20) Domestic Water Supply Reservoir - An existing or proposed open, uncovered reservoir used or intended to impound water for human consumption or domestic purposes, including a planned reservoir.

(21) Dosing Tank - A water tight receptacle constructed of approved materials designed to receive and store clarified effluent and convey it to a pretreatment device or a disposal field under positive pressure. The dosing tank is equipped with a pump(s), effluent screen, and level control and alarm floats.

(22) Drainage Area - All the land that can, or may, drain into a domestic water supply reservoir, whether or not the topographical configuration is artificially or naturally caused.

(23) Drainage Well - A well constructed for the purpose of disposing wastewater, hazardous materials, storm water or drainage water.

(24) Dwelling- Any structure, or portion thereof, which is used, intended, or designed to be occupied for human living purposes including, but not necessarily limited to, houses, houseboats, mobile homes, hotels, motels, apartments, and condominiums.

(25) Effective Sidewall Area of Trench - The portion of the sidewalls of a leaching trench containing effective soil and extending upward from the bottom of the trench to the approximate height of the invert of the perforated pipe installed in the leaching trench.

(26) Effective Soil - Undisturbed, native soil having an acceptable percolation rate and located above a limiting condition including, but not limited to the highest level of permanent, perched, or seasonal ground water, bedrock, fractured or fissured rock, or any layer that impedes movements of water or air, or growth of plant roots, or that will not retain sewage for an adequate time period to allow for proper treatment of sewage prior to it reaching groundwater. Effective soil does not include fill material.

(27) Ephemeral Stream - An observable watercourse that flows only in direct response to precipitation. It receives no water from springs and no long-term supply from melting snow or other surface source. Its stream channel is at all times above the local water table. Any watercourse that does not meet this definition is to be considered a perennial stream for the purposes of these standards.

(28) Equal Distribution- A method of sewage effluent disposal that distributes the flow to the disposal field in such a manner that all distribution lines receive an equivalent volume of effluent concurrently, and if pressurized, evenly throughout their length.

(29) Existing On-Site Sewage Disposal System - An on-site sewage disposal system in existence prior to the effective date of these standards.

(30) Experimental System - Those systems that:

(a) Are alternative systems installed into areas where surface and/or subsurface conditions do not comply with these standards; and/or

(b) Are not allowed for individual on-site sewage disposal for subdivision of land or new construction without being approved and under permit from the Regional Water Quality Control Board having jurisdiction; and/or

(c) Use construction materials other than those noted for standard systems and non-experimental alternative systems in these standards.

(31) Failing or Failed System- An on-site sewage disposal system which causes or results in any of the following conditions:

(a) Failure to accept wastewater discharge creating a backing of wastewater into the structure served by the system.

(b) The discharge of wastewater to the surface of the ground.

(c) The discharge of wastewater to surface waters or groundwater.

(d) The lack of an unsaturated vertical soil separation between the bottom of a disposal field and seasonal high groundwater.

(e) Wastewater level in a disposal field standing at least one inch above the invert of the perforated pipe or other means of wastewater distribution within the disposal field.

(f) An alternative system with sample results exceeding 240,000/100 ml most probable number (MPN) total coliform bacteria and/or 2.2 MPN fecal coliform from purged wells located twenty five (25') feet or further down gradient. Exception: if the up gradient performance wells have similar contamination levels as down gradient wells, then the contamination is deemed to be background in the area.

(32) Fractured Rock - Material that is composed of over fifty (50%) percent coarse fragments by volume.

(33) Greywater - Untreated household wastewater that has not come in contact with toilet or food wastes. Greywater includes used water from bathtubs, showers, wash basins and water from clothes washing machines and laundry tubs. It does not include wastewater from kitchen sinks, dishwashers or laundry water from soiled diapers.

(34) Groundwater - Subsurface water that is in the zone of saturation. Includes perched water tables, shallow regional groundwater tables or aquifers, or zones that are seasonally, periodically, or permanently saturated.

(35) Hardpan - An irreversibly hardened layer caused by the cementation of soil particles. The cementing agent may be silica, calcium carbonate, iron, or organic matter.

(36) Header Pipe- The solid line that receives wastewater from a manifold or distribution box and conveys it to the disposal field.

(37) Holding Tank - A water tight receptacle designed to receive and store wastewater for removal and disposal at another location.

(38) High Water Level - The highest known or recorded flood water elevation during a ten year event of any lake, stream, pond, reservoir, ditch, canal, culvert, or drainage way.

(39) IAPMO - International Association of Plumbing and Mechanical Officials.

(40) Impermeable Soil Layer - Any layer of soil having a percolation rate slower than 120 minutes per inch (1/2 inch per hour).

(41) Incompatible Use - Any activity or land use that would preclude or damage an area for use as a sewage disposal site. Includes but is not limited to the construction of buildings, roads or other structures that may result in the compaction, displacement, or removal of existing soil.

(42) Industrial Waste - Any liquid, gaseous, radioactive, or solid waste substance, or combination thereof, resulting from any process of industry, manufacturing, trade, or business, or from the development or recovery of any natural resources.

(43) Invert - The lowest internal portion of the internal cross-section of a pipe or fitting.

(44) Leach Line - A trench with vertical sides and substantially flat bottom and filled with drain rock into which perforated pipe or other means of wastewater distribution has been laid.

(45) Limiting Condition - Includes, but is not restricted to the highest level of permanent, perched, or seasonal ground water, hardpans, claypans, impermeable soil, weak or massively structured clays or silty clays, coarse sand, cemented soil, plastic soil, fragipans, compacted soil, bedrock, fractured or fissured rock, saprolite, clay soil, soil containing more then fifty (50%) percent coarse fragments by volume as retained on a #10 sieve, any layer that impedes movements of water or air, or growth of plant roots, or that will not retain sewage for an adequate time period to allow for proper treatment of sewage prior to it reaching groundwater.

(46) Limiting Soil Layer - Also known as restrictive soil layer is the portion of the soil profile that most restricts the successful operation of a leachfield to treat and dispose of sewage effluent without causing contamination.

(47) Lot - as defined by Chapter 26 of the Solano County Code.

(48) Manifold Pipe - Tightline that interconnects perforated pipe in a disposal field, or which receives wastewater from a septic tank or dosing tank for distribution to leach lines.

(49) Mottles - Spots or streaks of contrasting soil colors. For purposes of groundwater determination this term shall refer to those features formed in the soil during periods of saturation from the process of reduction, translocation, and oxidation of iron and manganese found in some soils. Such features remain evident in dry soils after the saturation event has occurred. These redoximorphic features of soils (mottles and gleying) are used to indicate poor aeration, ground water levels, and lack of drainage. Soils lacking iron and manganese, such as sand, will not show mottles even if saturated.

(50) On-Site Sewage Disposal System - Also termed septic system, or sewage disposal system, means any system of piping, treatment devices, appurtenant components, or other facilities that convey, store, treat, or dispose of wastewater onto or into the ground for subsurface treatment and disposal on the same lot from which the waste flow is generated. This term includes both standard and alternative systems. Individual on-site sewage disposal systems dispose of sewage effluent into a private disposal field located on the lot where the sewage originates and is privately owned and operated by the lot owner. Community on-site sewage disposal systems receive sewage from two or more separate lots and dispose of it into a shared disposal field located on another separate lot. A community on-site sewage disposal system is owned, operated, and maintained in accordance with the Solano County General Plan by a government agency, public utility, maintenance district, or other similar entity approved by the Local Agency Formation Commission and is approved by and operated under permit from the Regional Water Quality Control Board.

(51) Operation permit: Gives approval for operation of an alternative or experimental system in conformance with the operation permit conditions and these standards.

(52) Perched Water - A subsurface body of water separated from the main groundwater body by a relatively impermeable stratum above the main groundwater body.

(53) Percolation Test - A soil test performed to estimate the absorption capability of the soil.

(54) Perennial Stream - A river or stream which flows continuously, or which flows in response to a spring source, and which is, during the wet season, confluent with a local water table. A perennial stream may or may not flow year round, but does flow in response to surface or subsurface water not associated exclusively with a rain event.

(55) Perforated Pipe - Pipe used in the dispersion of wastewater into leach lines.

(56) Pit Privy - A structure used for disposal of human waste without the aid of water. It consists of a pit or vault in the ground into which human waste is deposited.

(57) Plumbing Fixtures - Receptacles, devices or appliances which are supplied with water, or which receive liquid or liquid-borne wastes and discharge such as 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 considered plumbing fixtures.

(58) Pressure Distribution - A method of effluent distribution designed to distribute wastewater equally and evenly throughout an absorption field by placing the liquid effluent under pressure in the pipe.

(59) Program Manager - The Program Manager of the Solano County Environmental Health Services Division.

(60) Property Owner - The person(s), firm(s), trust(s), or other entity(ies) listed in the records of the Solano County Assessor as the current owner of any subject lot.

(61) PVC - Polyvinyl chloride.

(62) Registered Consultant - is a Registered Civil Engineer, Registered Geologist, Certified Engineering Geologist, Registered Environmental Health Specialist, or Certified Professional Soil Scientist. All Registrations must be by the state of California.

(63) Reserve Area - Also known as “replacement area”, is an area on a lot equal in size and in suitability to the existing leachfield designated for future placement of a new sewage disposal system complying with these standards.

(64) Repair - The installation, modification, or replacement of any portion of a sewage disposal system or appurtenant feature necessary to eliminate or prevent a public health hazard, abate a nuisance, prevent the pollution of surface and ground waters caused by a failed or failing on-site sewage disposal system, or correct a violation of these standards. It may include repair or replacement of a disposal field, septic tank, piping, or any appurtenant components.

(65) Riser - A structure that allows access to the access ports of a septic tank, dosing tank, or interceptor.

(66) Sanitary Sewer - Also called “sewer”, is a sewer system owned or operated by a city, town, municipal corporation, county, political subdivision of the state, or other approved ownership which consists of a collection system and necessary trunks, pumping facilities and a means of final treatment and disposal and which has been approved and is under permit from the appropriate California Regional Water Quality Control Board.

(67) Sanitary Tee - A pipe extending above and below the liquid level in a septic tank, dosing tank, interceptor or other receptacle that is attached to the inlet or outline pipe of said tanks.

(68) Saturated Soil - The condition of soil when all available soil pore space is occupied by water and the soil is unable to accept additional moisture. In fine textured soils, the free water surface may not be apparent. The highest level of saturation can be estimated by the highest extent of soil mottling or gleying.

(69) Scum - A mass of sewage solids floating at the surface of wastewater within a septic tank, interceptor, or dosing tank, and which is buoyed up by entrained gas, grease, or other substances.

(70) Seepage Pit - Any excavation in the ground five feet or more in depth that receives and disposes of septic tank effluent.

(71) Septage - The solid and liquid contents of a septic tank, interceptor, holding tank, pit privy, dosing tank, chemical toilet, or on-site sewage disposal system. Also referred to as “cleanings” or “pumpings”.

(72) Septic Tank - A watertight tank which receives and partially treats wastewater through processes of sedimentation, flotation, and bacterial action so as to separate solids from the liquid in the wastewater and that discharges the liquid directly to a disposal field or dosing tank.

(73) Sewage - Any liquid waste containing water mixed with animal or vegetable matter, soaps, detergents, or chemicals in suspension or solution. Liquid waste includes kitchen, bath, laundry, office, processing and kennel wastes from residential, commercial, industrial, and agricultural buildings, facilities, or locations.

(74) Slope - The rate of fall or drop in elevation per 100 feet of the ground surface, or fraction thereof. It is expressed as percent of grade.

(75) Soil - Unconsolidated earthen materials over bedrock which is 2 millimeters in diameter or smaller and which falls within a soil textural class as specified in the USDA Soil Triangle.

(76) Soil Color - The moist color of soil based on Munsell soil color charts.

(77) Soil Horizon - A layer of a soil that is distinguishable from adjacent layers by characteristic physical properties such as structure, color, texture, or by chemical composition, including content of organic matter or degree of acidity or alkalinity.

(78) Soil Profile - An excavation displaying soil horizons in an area proposed for wastewater disposal to ascertain its suitability for that purpose. Characteristics of soil examined in a soil profile may include soil structure, soil texture, color, impervious layers, or evidence of groundwater as determined by direct observation or presence of soil mottles.

(79) Soil Structure - The arrangement of primary soil particles into compound particles or clusters that are separated from adjoining aggregates and have properties unlike those of an equal mass of unaggregated primary soil particles.

(80) Soil Texture - The relative proportions of sand, silt, and clay, as defined by the classes of the USDA Soil Triangle.

(81) Spring - A flow of water from the earth that occurs spontaneously where the water table stratum emerges to the surface of the earth. This term includes but is not limited to gravity springs, artesian springs, seepage springs, tubular springs, and fissure springs.

(82) Standard System - An on-site sewage disposal system that uses gravity to disperse effluent throughout the disposal field, and in which no pretreatment device is utilized. 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 absorption field placed in an area with surface and subsurface features complying with these standards.

(83) Structure - Any building including, but not limited to, swimming pools, above ground pools, mobile homes, porches and steps (whether covered or uncovered), breezeways, roofed patios, decks, carports, covered walks, covered driveways, or similar structures or appurtenances.

(84) Subdivision - The division of land as defined by the Solano County Subdivision Ordinance.

(85) Tentative Map - Includes both tentative map and tentative parcel map, as used in Chapter 26 of the Solano County Code.

(86) Tight Line - All watertight piping located downstream of the building drain. This term includes, but is not necessarily limited to, the building sewer, manifold, header pipe, and transmission line.

(87) UL - Underwriter’s Laboratory.

(88) UPC - Uniform Plumbing Code.

(89) Unstable Landform - Areas showing evidence of mass down slope movement such as debris, flow, landslides, rockfalls, and hummocky hill slopes, or actively eroding bluffs.

(90) USDA - United States Department of Agriculture.

(91) Well - Any artificial excavation of approximately tubular shape constructed by any method for the purpose of extracting water from, or injecting water or other liquid into the ground; for observation of groundwater for any reason; for the exploration of the subsurface of the earth; for removal of substances from soil or groundwater; or for cathodic protection.

(Ord. No. 1609, §18; Ord. No. 1655, §48, §49)