Wyoming Administrative Code › Agency 020 - Environmental Quality, Dept. of › Sub-Agency 0011 - Water Quality › Chapter 25 - SEPTIC TANKS, SOIL ABSORPTION SYSTEMS, AND OTHER SMALL WASTEWATER SYSTEMS › Section 25-4 - Definitions

Current through July 13, 2024
(a) "100 year
				floodplain" means a tract of land throughout a watershed that has a one-in-one
				hundred chance or occurrence of flooding in any given year or a return period
				of once every 100 years , as determined by the United States Geological Survey
				(USGS), Federal Emergency Management Agency (FEMA) or a local planning and
				development authority.
(b)
				"Absorption surface" means the interface where treated effluent infiltrates
				into native or fill soil.
(c) "Bed"
				means a soil treatment and dispersal system where the width is greater than
				three (3) feet.
(d) "Bedrock" means
				geological layers, of which greater than fifty percent (50%) by volume consist
				of unweathered in-place consolidated rock or rock fragments. Bedrock also means
				weathered in-place rock that cannot be hand augered or penetrated with a knife
				blade.
(e) "Bedroom" means any room
				that is or may be used for sleeping.
(f) "Blackwater" means water containing fecal
				matter and/or urine.
(g) "Five day
				biochemical oxygen demand (BOD5)" means a measurement of the dissolved oxygen
				used by microorganisms in the biochemical oxidation of organic matter during a
				five (5) day period.
(h) "Building
				sewer" means the pipe that carries wastewater from the building.
(i) "Chamber" means a domed open bottom
				structure that is used in lieu of perforated distribution pipe and gravel
				media.
(j) "Delegated small
				wastewater program" means a local governmental entity, delegated by the
				Administrator, with the authority to administer the provisions of
				W.S. 35-11-301(a)
				(iii) for small wastewater systems pursuant
				to the provisions of
				W.S.
				35-11-304.
(k) "Direct human consumption food crops" are
				crops consumed directly by humans. These include but are not limited to fruits,
				vegetables, and grains grown for human consumption.
(l) "Domestic wastewater" means a combination
				of the liquid or water-carried wastes from residences, business buildings,
				institutions, and other establishments arising from normal living
				activities.
(m) "Domestic septage"
				means liquid or solid material removed from a waste treatment vessel that has
				received only wastes from residences, business buildings, institutions, and
				other establishments arising from normal living activities.
(n) "Dosing tank" means a tank equipped with
				an automatic siphon or pump designed to discharge effluent on an intermittent
				basis.
(o) "Effluent" means liquid
				flowing out of a septic tank, other treatment vessel, or system.
(p) "Effluent filter" means a removable,
				cleanable device inserted into the outlet piping of a septic tank or other
				treatment vessel designed to trap solids that would otherwise be transported to
				the soil absorption system or other downstream treatment components.
(q) "Evapotranspiration" means the combined
				loss of water from soil by evaporation from the soil or water surface and by
				transpiration from plants.
(r)
				"Greywater" means untreated wastewater that has not been contaminated by any
				toilet discharge; that is unaffected by infectious, contaminated, or unhealthy
				bodily wastes; and does not present a threat from contamination by unhealthful
				processing, manufacturing, or operating wastes. "Greywater" includes but is not
				limited to wastewater from bathtubs, showers, washbasins, clothes washing
				machines (unless soiled diapers are serviced), laundry tubs, and kitchen
				sinks.
(s) "Grease interceptor"
				means a device designed to separate fats, oils, and grease from
				wastewater.
(t) "Groundwater" means
				subsurface water that fills available openings in rock or soil materials such
				that they may be considered water saturated under hydrostatic
				pressure.
(u) "High groundwater"
				means seasonally or periodically elevated levels of groundwater.
(v) "High strength wastewater" means a
				wastewater stream with a BOD5 higher than 200 mg/L.
(w) "Holding tank" means a watertight
				receptacle designed to receive and store wastewater.
(x) "Manifold" means a non-perforated pipe
				that distributes effluent to individual distribution pipes.
(y) "Mound system" means an onsite wastewater
				system where any part of the absorption surface is above the elevation of the
				existing site grade and the absorption surface is contained in a mounded fill
				body above the grade.
(z) "Mulch
				basin" means an excavated area that has been refilled with a highly permeable
				media, organic and inorganic materials intended to distribute greywater to
				irrigate vegetation.
(aa)
				"Pathogens" are disease-causing organisms. These include, but are not limited
				to certain bacteria, protozoa, viruses, and viable helminth ova.
(bb) "Percolation rate" means the time
				expressed in minutes per inch required for water to seep into saturated soil at
				a constant rate.
(cc) "Pipe invert"
				means the bottom of the internal surface of the pipe.
(dd) "Percolation test" means the method used
				to measure the percolation rate of water into soil as described in Appendix
				A.
(ee) "Permit by rule" means an
				authorization included in these rules that does not require either an
				individual permit or a general permit. A facility that is permitted by rule
				must meet the requirements found in this chapter, but is not required to apply
				for and obtain a permit to construct and operate the facility.
(ff) "Pressure distribution" means a network
				of pipes in which effluent is forced through orifices under pressure.
(gg) "Restrictive layer" means a nearly
				continuous layer that has one or more physical or chemical properties that
				significantly impede the movement of water and air through the soil or that
				restrict roots or otherwise provide unfavorable root conditions. Examples are
				bedrock, cemented layers, and dense layers.
(hh) "Septage" means liquid or solid material
				removed from a waste treatment vessel that has received wastes from residences,
				business buildings, institutions, and other establishments.
(ii) "Septic tank" means a watertight tank
				designed and constructed to receive and treat raw wastewater
(jj) "Serial distribution" means a group of
				trenches arranged so that the total effective absorption area of one trench is
				used before liquid flows into the next trench.
(kk) "Service provider" means a person
				authorized and trained by a system manufacturer or their vendor to operate and
				maintain any proprietary system.
(ll) "Soil absorption system" means a
				shallow, covered, excavation surface, or mound made in unsaturated soil into
				which wastewater effluent from the septic tank is discharged through
				distribution piping for application onto absorption surfaces through porous
				media or manufactured components.
(mm) "Trench" means an absorption surface
				with a width of three (3) feet or less.