Decentralized Wastewater Glossary

Setting of operational controls, verification of component function, documentation of initial operating conditions of a system, and establishment of microbial populations for biological treatment.

Fixed component of total dynamic head (TDH); expressed as the sum of elevation head and operating pressure; see also operating pressure.

Plow shank used for installing subsurface drip tubing; typically a disc leads the shank to cut the soil, grass, and other debris prior to shank passage.

Point where a rod reading is taken; points along the line of a survey; stations are usually marked with a peg or wood stake, or in grade settling, marked with a grade stake.

See septic tank effluent gravity.

See septic tank effluent pump.

Device used to connect a trench at a certain elevation to the next trench at a lower elevation; can be used as a relief line in sequential or serial distribution; see also cross-over pipe and relief device.

Lagoon where some form of wastewater is stored before it is either conveyed to another component for further processing or is reused.

Runoff resulting from precipitation.

Conduit used to convey wastewater either directly from the source or following septic tank pretreatment to the land surface or a water body; term that often indicates an illegal discharge without treatment.

Ramp built of steel or wood, usually used for vehicle access; ramps made of soil or rock are not considered structural ramps.

Group of soil structures recognized in the Field Book for Describing and Sampling Soils (Schoenberger, et al, 2002); includes three subcategories that essentially have no structural units: single grain (entirely non-coherent; e.g. loose sand), massive (material is a coherent mass {not necessarily cemented}, no secondary pores), and massive - rock controlled fabric (coherent mass with the original rock fabric still identifiable).

Portion of the main line located after a flow splitter that carries a portion of flow to a spray dispersal field.

See blocky.

See sub-main line.

constructed wetland in which wastewater passes through the component below the surface of the media.

soil which is underwater or is freely seeping.

pump with a hermetically sealed motor close-coupled to the pump housing, designed to be placed entirely below the surface of the liquid to be pumped.

underground conduit used to collect and convey surface or groundwater.

drip field designed and installed such that the drip tubing is located at least 6” below finished grade of native soil.

see soil treatment area (STA).

a general term for the highest point of any landform remanant, hill, or mountain.

tank or pit that receives drainage of groundwater or runoff, stores it temporarily, and from which the discharge is pumped.

piping between a source of effluent and the associated gravity-flow or pressure distribution system.

manifold that allows effluent to be distributed to two or more laterals.

structure such as underpinning, bracing, or shoring, which provides support to an adjacent structure, underground installation, or the sides of an excavation.

natural or constructed drainage feature used to divert runon and/or collect runoff and direct it to an effective outlet; see also swale and berm.

drip field designed and installed such that the drip tubing is located at the finished grade of the soil surface.

see runoff.

any body of water, whether fresh or marine, flowing or contained in natural or artificial, lined or unlined depressions for significant periods of the year; includes natural and artificial lakes, ponds, springs, rivers, streams, wetlands, and tidal waters.

flow of effluent that occurs in a short enough period that it upsets the function of one or more components of the treatment train.

see flow equalization tank.

1. volume above the average daily volume and below the reserve volume in a flow equalization tank; 2. volume of effluent in excess of average daily flow.

determining the dimensions and contour (or three-dimensional characteristics) of the earth’s surface by the measurement of distances, directions and elevations.

microorganisms maintained in suspension within a liquid; see also suspended growth process.

configuration wherein the microorganisms that provide treatment are maintained in suspension within a liquid; see also attached growth process.

that portion of total solids that is retained on a filter of 2.0 µm (or smaller) nominal pore sized under specified conditions.

natural or constructed elongated, sloped depressional drainage feature used to collect runoff and direct the flow to an effective outlet to prevent runon downslope; often used in conjunction with a berm;                               see also  berm.

non-return valve in which a hinged flapper seats against an opening within a cylindrical fluid line and stops flow.

piping and connections used to adjust the elevation of and isolate spray distribution heads from the lateral in a spray dispersal system.

distance from two fixed points to locate a system component.

valve used to manually or automatically direct flow from one final treatment and dispersal component to another.

assembly of components and processes; see also treatment train.

graphical method that describes the relationship between total dynamic head and flow in a system under operating conditions.

complete range of activities necessary to conduct operational services on wastewater treatment systems, including inspection, operation, maintenance, monitoring, and compensation.

information displayed in tables and charts, approved by a registered professional engineer, and used to design and construct a protective system.

activities related to preparing to bid a system installation including reading blueprints and specifications; making notes of special details concerning the project after gathering the necessary information; and estimating the quantities of labor, materials, equipment and special items needed to complete the job.

watertight structure or container used to hold wastewater for such purposes as aeration, equalization, holding, sedimentation, treatment, mixing, dilution, or addition of chemicals, or disinfection.

1. regarding a septic tank, volume in gallons as measured from the bottom of the tank to the invert of the outlet piping; 2. regarding a dosing tank, volume as measured from the bottom of the tank to the invert of the inlet.

total volume of a tank from the inside bottom of the tank to the inside top of a tank; see also tank capacity.

integration of telecommunications and informatics (information analytics) technology to monitor and manage assets.             

remote communication of system status, typically incorporating an auto-dialing notification feature.            

advanced treatment of wastewater for enhanced organic matter removal, pathogen reduction, and nutrient removal; typical standards for tertiary effluent vary according to regulatory requirements.

type of media filter which uses non-rigid, synthetic material of varying shapes and configurations as the media; typically packaged as prefabricated modular units.

bacteria which grow best at temperatures between 35- and 75- degrees C (95- and 167- degrees F) with optimum growth between 55- and 65- degrees C (131- and 149- F).

1. A liquid level sensing arrangement in a simplex pumping system using three float switches: a float switch assembly consisting of an on float (activation) and an off float (deactivation) for pump operation and a single differential float switch for high water alarm activation; 2. A liquid level sensing arrangement in a multiplex pumping system using three single differential float switches: a stop float switch, a lead float switch and a lag/alarm float switch for lag pump activation and high water alarm activation.

rough pore of concrete installed on the outside of an angled fitting (tee, cross, elbow or valve) that extends back to the native soil to provide a greater bearing surface and prevent loosening of joints due to stress created in pressurized applications.

large-scale subsurface drainage system designed for lowering groundwater for agricultural purposes.

configuration in which a specific volume of effluent is delivered to a component based upon a prescribed interval, regardless of facility water use; see also flow equalization.

controller for automatically starting and/or stopping a device at a given interval.

operating parameter that allows pump operation via a specified schedule; see also peak enable and redundant off.

operating parameter under which a sensor directly activates the pump when the effluent level reaches a preset, excessively high level; pump operation continues in essentially demand mode until the effluent drops below the override sensor off elevation; the primary timer remains engaged but does not control activation until override sensor drops out; the timer override sensor operates on a demand basis.

the hillslope position that forms a gently inclined surface at the base of a slope. Toeslopes in profile are commonly gentle and linear, and are constructional surfaces forming the lower part of a slope continuum that grades to a valley or closed depression (Hawley and Parsons, 1980). Compare summit, shoulder, backslope, footslope, valley floor.

fixture used for defecation and urination.

configuration in which a short manifold is installed at the higher elevation of a soil treatment area.

plotted form of information gained through a topographic survey.

see topographic survey.

survey made for locating objects and measuring the relief, roughness, or three-dimensional variations of the earth’s surface; detailed information is obtained pertaining to elevations as well as to the locations of man-made and natural features (buildings, roads, streams, etc.); also known as a topographic map.

physical features of the land surface including relative elevations and geometry.

measurement of water quality expressed as the number of colony-forming units (CFU) of coliform bacteria per unit volume; see also colony-forming unit (CFU) and heterotrophic plate count.

material that passes through a filter of 2.0 µm (or smaller) nominal pore size, evaporated to dryness in a weighed dish and subsequently dried to constant weight at 180 degrees C; typically expressed in mg/L.

measure of the cumulative energy that a pump must impart to a liquid to move it from one point to another, consisting of the sum of friction head (as based upon piping diameter, system configuration, and flow rate) and static head (the sum of elevation head and operating pressure); see also friction head, static head, and operating pressure.

measure of the total concentration of organic nitrogen, ammonia (NH₃), and ammonium nitrogen (NH₄⁺).

measure of the complete nitrogen content in wastewater including nitrate (NO₃^-), nitrite (NO₂^-), ammonia (NH₃), ammonium (NH₄⁺), and organic nitrogen, expressed as mg/L of N; all these forms of nitrogen, (as well as nitrogen gas [N₂]), can be biochemically converted from one form to another and are constituents of the nitrogen cycle.

measure of the concentration of organic carbon determined by oxidation of the organic matter into carbon dioxide (CO₂) typically expressed in mg/L.

sum of all forms of phosphorus in effluent.

material residue left in a vessel after evaporation of a sample after drying to a constant weight in an oven at 217 to 221 degrees F (103 to 105 degrees C); includes total suspended solids (TSS) and total dissolved solids (TDS); typically expressed in mg/L.