Washington Administrative Code › Title 246 - Health, Department of › SEWER SYSTEMS › Chapter 246-272B - Large on-site sewage system regulations › Part 1 - GENERAL PROVISIONS › Section 246-272B-01100 - Acronyms and definitions

Current through Register Vol. 24-14, July 15, 2024
The following acronyms and definitions apply throughout
					 this chapter unless the context clearly requires otherwise:
(1) "Additive" means a commercial product
				  added to an OSS intended to affect performance or aesthetics of an
				  OSS.
(2) "ASTM" means American
				  Society for Testing and Materials.
(3) "Bank" means any naturally occurring
				  slope greater than one hundred percent (forty-five degrees) and extending
				  vertically at least five feet from the toe of the slope to the top of the
				  slope.
(4) "Bed" means a drainfield
				  component consisting of an excavation with a width greater than three feet and
				  up to ten feet.
(5) "BOD" means
				  biochemical oxygen demand, typically expressed in mg/L.
(6) "Building sewer" means that part of the
				  horizontal piping of a drainage system extending from the building drain, which
				  collects sewage from all the drainage pipes inside a building, to an OSS. It
				  begins two feet outside the building wall and conveys sewage from the building
				  drain to the remaining portions of the OSS.
(7) "CBOD" means carbonaceous biochemical
				  oxygen demand, typically expressed in mg/L.
(8) "Cesspool" means a pit receiving
				  untreated sewage and allowing the liquid to seep into the surrounding soil or
				  rock.
(9) "Covenant" means a
				  recorded agreement stating certain activities or practices are required or
				  prohibited.
(10) "Cover material"
				  means soil placed over a drainfield or dripfield composed predominantly of
				  mineral material with no greater than ten percent organic content. Cover
				  material may contain an organic surface layer for establishing a vegetative
				  landscape to reduce soil erosion.
(11) "Cut" means any artificially formed
				  slope greater than one hundred percent (forty-five degrees) and extending
				  vertically at least five feet from the toe of the slope to the top of the
				  slope.
(12) "Department" means the
				  Washington state department of health.
(13) "Design engineer" means a professional
				  engineer who is licensed in Washington state under chapter 18.43 RCW and is
				  experienced and qualified in the analysis and design of LOSS or sewage
				  treatment system components. If the LOSS or any component of the LOSS is
				  considered a "significant structure" as defined in chapter 18.43 RCW, the
				  design engineer shall be licensed as a structural engineer unless an exception
				  specified in
				  RCW
				  18.43.040 applies.
(14) "Design flow" means the maximum volume
				  of sewage a residence, structure, or other facility is estimated to generate in
				  a twenty-four-hour period. It incorporates both an operating capacity and a
				  surge capacity for the LOSS during periodic heavy use events.
(15) "Development" means a combination of
				  residences, structures, and facilities, or similar activity, in or on
				  subdivisions, sites, or areas, where residential strength sewage is
				  produced.
(16) "Distribution
				  technology" means any arrangement of equipment or materials that distributes
				  LOSS effluent within the drainfield.
(17) "Domestic sewage" means urine, feces,
				  and the water carrying human wastes, including kitchen, bath, and laundry
				  wastes from residences, nonresidential buildings such as churches or schools,
				  commercial establishments, or other buildings, excluding industrial wastewater
				  and storm water.
(18) "Drain rock"
				  means clean washed gravel or crushed rock ranging in size from three-fourths
				  inch to two and one-half inches, and containing no more than two percent by
				  weight passing a US No. 8 sieve and no more than one percent by weight passing
				  a US No. 200 sieve.
(19)
				  "Drainfield" means the treatment and soil dispersal component of a LOSS
				  consisting of trenches or beds containing either a distribution pipe within a
				  layer of drain rock covered with a geotextile or equivalent covering, or an
				  approved gravelless distribution technology, designed and installed in
				  original, undisturbed, unsaturated soil providing at least minimal vertical
				  separation as established in this chapter, with pressure distribution of
				  effluent.
(20) "Dripfield" means a
				  type of drainfield where effluent is applied directly into the soil through
				  driplines.
(21) "Dripline" means
				  the distribution piping used with a subsurface drip system to discharge
				  effluent into the soil. A dripline consists of small diameter, flexible
				  polyethylene tubing with small in-line emitters.
(22) "Drywell" means a subterranean pit,
				  chamber, or structure used to collect storm water, effluent, or other liquid
				  and disperse it into the soil.
(23)
				  "Effective particle size" means the size of sieve opening where ninety percent
				  by weight of a sample of filter media is retained on the sieve and ten percent
				  passes through the sieve.
(24)
				  "Effluent" means liquid discharged from a septic tank or other LOSS treatment
				  component.
(25) "Emitter" means an
				  orifice that discharges effluent at a slow, controlled rate.
(26) "Expansion" means a change to the LOSS
				  or its influent that causes the LOSS to exceed its existing treatment or
				  dispersal capacity, or a change that reduces the treatment or dispersal
				  capacity of the existing LOSS.
(27)
				  "Extremely gravelly" means soil with sixty to ninety percent rock fragments by
				  volume.
(28) "Failure" means a
				  condition of a LOSS or LOSS component that threatens the public health or
				  environment by inadequately treating sewage or by creating a potential for
				  direct or indirect contact between sewage and the public.
(29) "FC" means fecal coliform bacteria,
				  typically expressed in number of colonies/100 ml.
(30) "Fecal coliform" means bacteria common
				  to the digestive systems of warm blooded animals that are cultured in standards
				  tests. Counts of these organisms are typically used to indicate potential
				  contamination from sewage or to describe a level of needed disinfection, and
				  are generally expressed as colonies per 100 ml.
(31) "gpd" means gallons per day.
(32) "Gravelly" means soils with fifteen to
				  thirty-four percent rock fragments by volume.
(33) "Greywater" means domestic type flows
				  from bathtubs, showers, bathroom sinks, washing machines, dishwashers, and
				  kitchen or utility sinks. Greywater does not include flow from a toilet or
				  urinal.
(34) "Gross land area"
				  means the total land area of a proposed development that might include the
				  centerline of adjoining road or street right of ways, if dedicated as part of
				  the development, but does not include land area under surface water.
(35) "Groundwater" means water in a saturated
				  zone or stratum beneath the surface of land or below a surface water.
(36) "High quality effluent (HQE)" means a
				  treatment level higher than Treatment Level B as established in WAC
				  246-272B-06250.
(37) "Holding tank sewage system" means a
				  LOSS that incorporates a sewage tank without a discharge outlet, and requires
				  the services of a sewage pumper, and off-site treatment and disposal for the
				  generated sewage.
(38) "Hydraulic
				  loading rate" means the rate at which effluent is applied to a drainfield or
				  other treatment component usually expressed as gpd/sf.
(39) "Hydrogeologist" means a professional
				  hydrogeologist who is licensed in Washington state under chapter 18.220
				  RCW.
(40) "HGR" means hydrogeology
				  report.
(41) "HQE" means high
				  quality effluent.
(42) "Industrial
				  wastewater" means the water or liquid carried waste from an industrial process.
				  This waste may result from any process or activity of industry, manufacture,
				  trade, or business; from the development of any natural resource; or from
				  animal operations such as feedlots, poultry houses, or dairies. The term
				  includes contaminated storm water and leachate from solid waste
				  facilities.
(43) "Infiltrative
				  surface" means the horizontal surface area measured in square feet within a
				  drainfield to which effluent is applied and through which effluent moves into
				  original undisturbed soil or other porous treatment media.
(44) "Influent" means the domestic sewage
				  entering the LOSS.
(45) "Installer"
				  means a person who installs or repairs an OSS and who meets the requirements in
				  WAC 246-272B-05000.
(46) "Large on-site sewage system (LOSS)"
				  means an OSS with design flows of three thousand five hundred gpd up to and
				  including one hundred thousand gpd.
(47) "Local health officer" means the legally
				  qualified physician who has been appointed as the health officer for the county
				  or district public health department as defined in
				  RCW
				  70.05.010, or his or her authorized
				  representative.
(48) "LOSS" means
				  large on-site sewage system.
(49)
				  "Maintenance" means the actions necessary to keep the OSS and its components
				  functioning to protect public health and the environment.
(50) "Management entity" means a publicly or
				  privately owned entity acting as an agent of the owner responsible for the
				  proper and safe long-term management of the LOSS.
(51) "Massive structure" means soil that
				  appears as a coherent or solid mass not separated into peds of any
				  kind.
(52) "mg/L" means milligrams
				  per liter.
(53) "ml" means
				  milliliter.
(54) "mm" means
				  millimeter.
(55) "Moderate
				  structure" means well formed distinct peds evident in undisturbed soil. When
				  disturbed, soil material parts into a mixture of whole peds, broken peds, and
				  material that is not in peds.
(56)
				  "Modification" means a change to an existing LOSS that includes, but is not
				  limited to, a repair, an expansion, a replacement, treatment or other process
				  improvement, or a management or ownership change.
(57) "Monitoring" means routine observation
				  and measurement of LOSS performance to determine if it is functioning as
				  intended and if maintenance is needed. Monitoring also includes maintaining
				  accurate records documenting monitoring activities.
(58) "N10" means a
				  treatment level based on total nitrogen of 10 mg/L-N.
(59) "N20" means a
				  treatment level based on total nitrogen of 20 mg/L-N.
(60) "NEMA" means National Electrical
				  Manufacturer Association.
(61)
				  "NRCS" means Natural Resources Conservation Service.
(62) "O&G" means oils and
				  grease.
(63) "Oils and grease"
				  means a component of sewage typically originating from food stuffs or
				  consisting of compounds of alcohol or glycerol with fatty acids, typically
				  expressed in mg/L. Standard laboratory methods for determining O&G are
				  USEPA Method 1664 or Standard Methods 5520.
(64) "O&M" means operations and
				  maintenance.
(65) "On-site sewage
				  system (OSS)" means an integrated system of components, located on or nearby
				  the property it serves, that conveys, stores, treats, and provides subsurface
				  soil treatment and disposal of domestic sewage. It consists of a collection
				  system, a treatment component or treatment sequence, and a drainfield. It may
				  or may not include a mechanical treatment system. An OSS also refers to a
				  holding tank sewage system or other system that does not have a drainfield. A
				  holding tank that discharges to a sewer is not included in the definition of
				  OSS. A system into which storm water or industrial wastewater is discharged is
				  not included in the definition of OSS.
(66) "Operator" means a person who is
				  responsible for operating the LOSS and ensuring that it consistently and
				  reliably treats sewage according to the terms and conditions of the operating
				  permit, and who meets the requirements in WAC
				  246-272B-07200.
(67) "Operating capacity" means the average
				  daily volume of sewage that a LOSS can treat and disperse on a sustained
				  basis.
(68) "Ordinary high-water
				  mark" means the mark on lakes, streams, springs, and tidal waters found by
				  examining the beds and banks and ascertaining where the presence and action of
				  water are so common and usual, and so long continued in all ordinary years, as
				  to mark upon the soil a character distinct from that of the abutting upland
				  with respect to vegetation, as that condition exists on the effective date of
				  this chapter, or as it may naturally change thereafter. The following
				  definitions apply where the ordinary high-water mark cannot be found:
(a) The ordinary high-water mark adjoining
				  marine water is the elevation at mean higher high tide; and
(b) The ordinary high-water mark adjoining
				  freshwater is the line of mean high water.