S
-
site evaluation
Description and evaluation of soil characteristics (morphology, including structure, texture, and mineralogy; depth to limiting condition such as seasonal wetness; unsuitable soil structure or rock); site characteristics (including topography and landscape position), site features requiring setback distances (wells, water lines, structures, property lines, surface water, drainage and easements), and any other features impacting site suitability for effective treatment and dispersal of effluent.
-
site evaluator
Service provider who conducts site evaluations; see site evaluation.
-
site plan
Plan-view drawing that provides a graphical representation of existing and proposed natural and manmade physical features on a site.
-
site restoration
Reconstitution of the surface of a site to approach as nearly as possible the original grade and vegetative cover.
-
siting
Specification of the location for an OWTS based upon site features and characteristics.
-
slag
Bottom ash (a by-product of coal-fired power plants), the coarse fraction of which may be used as distribution media.
-
sleeve
-
slickensides
Stress surfaces in soil that are polished and striated and are produced by one mass sliding past another.
-
slope
1. Ratio of the rise divided by the run between two points, typically described as a percentage (rise/run multiplied by 100). 2. Landscape form or feature; see also slope, concave; slope, convex; and slope, linear.
-
slope break
Configuration for piping installed on steep slopes to slow the flow coming from the structure to the first tank; typically includes the installation of cleanouts to prevent obstruction.
-
slope stake
In earthwork, a stake marking the line where a cut or fill meets the original grade.
-
sloping (sloping system)
Method of protecting personnel by excavating in a manner to form sides that are inclined away from the excavation to prevent cave-ins; the angle of incline required to prevent a cave-in varies with the soil type, environmental conditions of exposure, and application of surcharge loads.
-
sloughing
Shedding material (typically biofilm) from the surface of media.
-
sludge
Accumulated solids and associated entrained water within a pretreatment component, generated during the biological, physical, or chemical treatment; coagulation; or clarification of wastewater.
-
sludge return
Process that sends the material (sludge) settled in a clarifier back to a septic or processing tank for further treatment or to maintain adequate microbial populations for treatment.
-
sludge return pump
-
soft malfunction
Component malfunction that does not disrupt overall system performance and can typically be corrected via maintenance or operational activities.
-
soil
1. Unconsolidated mineral and/or organic material on the immediate surface of the earth that serves as a medium for the growth of plants; 2. Unconsolidated mineral or organic matter on the surface of the earth that has been subjected to and shows effects of pedogenic and environmental factors of climate (including water and temperature effects), and macro- and microorganisms, conditioned by relief, acting on parent material over a period.
-
soil absorption field
See soil treatment area (STA).
-
soil consistence
Attribute of soil expressed in degree of cohesion and adhesion, or in resistance to deformation or rupture; consistence includes: the resistance of soil material to rupture, resistance to penetration, the plasticity, toughness, or stickiness of puddled soil material, and the manner in which the soil material behaves when subjected to compression; general classifications of soil consistence include loose, friable, very friable, firm, very firm, and extremely firm.
-
soil horizon
Layer of soil or soil material approximately parallel to the land surface and differing from adjacent related layers in physical, chemical, and biological properties or characteristics such as color, structure, texture, consistence, kinds and number of organisms present, degree of acidity or alkalinity, etc.
-
soil morphology
1. Physical constitution of a soil profile as exhibited by the kinds, thickness, and arrangement of the horizons in the profile; and by the texture, structure, consistence, and porosity of each horizon; 2. Visible characteristics of the soil or any of its parts.
-
soil mottles
Subordinate color in a soil horizon of a differing Munsell Color System notation; see also redoximorphic feature.
-
soil porosity
Volume percentage of the total bulk not occupied by solid particles.
-
soil profile
Vertical section of the soil through all its horizons and extending into the parent material.
-
soil separate
Mineral particle that is sand-, silt-, or clay-sized.
-
soil smearing
Degradation of the infiltrative surface through the sealing of soil pores.
-
soil structure
Combination or arrangement of primary soil particles into secondary units or peds; secondary units are characterized on the basis of shape, size class, and grade (degree of distinctness); see also structureless.
-
soil substitution
Trench or bed installed after native soil is excavated and replaced with approved soil material; configurations and terminology vary among jurisdictions; may be referred to locally as sand-lined trenches, liner systems, etc.
-
soil substitution bed
-
soil substitution trench
-
soil textural class
Percentage by weight of sand, silt, and clay such that each class possesses unique physical characteristics and management relative to the other textural classes; textural class names are modified by the addition of suitable adjectives when rock fragments are present in substantial amounts (for example, ‘stony silt loam’); see also soil classification system, OSHA.
-
soil texture
Relative proportions by weight of the various inorganic primary particles in a soil as described by the classes of soil texture.
-
soil treatment area
Physical location and associated structures (trenches, beds, fields, as appropriate) and distribution piping where final treatment and dispersal of effluent occurs.
-
solenoid
Electro-magnetically operated mechanical device (electric coil); see also valve, solenoid.
-
solenoid valve
Valve that uses an electro-magnetically operated mechanical device (electric coil) to turn on, shut off, or regulate the flow of effluent.
-
solids
1. Term used to collectively refer to the fractions of constituents in wastewater as identified through laboratory analysis; includes settleable, floatable, suspended, dissolved, volatile, fixed, organic or inorganic fractions. 2. Fraction of biochemically digestable constituents. 3. Accumulated sludge (settled solids), suspended microbial mass (mixed liquor suspended solids) or scum (floating solids) in a component.
-
solids storage
Defined portion of treatment component storage capacity reserved for accumulated solids; once that capacity is reached, solids must be removed from the component.
-
sorption
Removal of an ion or molecule from solution by adsorption and/or absorption; term often used when the exact nature of the mechanism of removal is not known.
-
source
Residence, business, institution or other facility where wastewater is generated.
-
spalling
Condition in which the surface of a concrete component is physically degraded (flaking), exposing aggregate and/or structural reinforcement materials.
-
spillway
-
spin filter
-
spirit level
Device for determining true horizontal or vertical directions by the centering of a bubble in a slightly curved glass tube or tubes filled with alcohol or ether.
-
splash plate
Hard surface designed to restrict downward flow of effluent and direct it horizontally.
-
splash pool
Hard surface and associated stored liquid volume designed to dissipate flowing energy before effluent distribution to the surrounding area.
-
split base
Method of dividing effluent flowing through a recirculating media filter using a physical barrier in the bottom of the filter resulting in multiple discharge locations.
-
splitter ball valve
See recirculating splitter valve (RSV).
-
spodic horizon
Diagnostic subsurface horizon characterized by the illuvial accumulation of amorphous materials composed of aluminum and organic carbon with or without iron.
-
spoil
Soil removed from its original location, typically stacked in a pile and may be reused.
-
spray dispersal
Application of effluent over a soil treatment area via sprinkler heads and associated devices and parts (including pump, filters, controls, and piping).
-
spray distribution
Pressurized distribution system that delivers treated effluent over an infiltrative surface through a network of piping, pressurized nozzles and associated devices.
-
spray field
Above-grade soil treatment area where final treatment and dispersal occurs via application of effluent to the infiltrative surface via pressurized distribution heads utilizing nozzles.
-
spring
Groundwater seeping out of the earth where the water table intersects the ground surface.
-
spring check valve
Non-return valve in which a spring causes a disc to seat against an opening within a cylindrical fluid line and stops flow.
-
spring line
Horizontal axis defined by the greatest width dimension of piping, conduit, tank, or other structure; see diagram at bedding.
-
sprinkler heads
-
squirt height
Height achieved by the liquid in a pressurized lateral when an orifice is positioned such that the discharge is vertical into the atmosphere, typically expressed in feet of height.
-
stable rock
Natural solid mineral material that can be excavated with vertical sides and will remain intact while exposed; unstable rock is considered to be stable when the rock material on the side or sides of the excavation is secured against caving-in or movement by rock bolts or by another protective system that has been designed by a registered professional engineer.
-
stake
1. Stout stick or post sharpened at one end and driven into the earth as a support or boundary marker. 2. Action of placing stakes on the perimeter of a property or a portion thereof to establish visible boundaries.
-
standard dimensional ratio (SDR)
Piping specification based upon the ratio of pipe diameter to wall thickness
-
standard methods
Shortened title for the Standard Methods for the Examination of Water and Wastewater, a joint publication of the American Public Health Association, American Water Works Association, and Water Pollution Control Federation; widely-used manual that outlines the procedures used to analyze water and wastewater impurities and characteristics.
-
standpipe
-
startup
Setting of operational controls, verification of component function, documentation of initial operating conditions of a system, and establishment of microbial populations for biological treatment.
-
static head
Fixed component of total dynamic head (TDH); expressed as the sum of elevation head and operating pressure; see also operating pressure.
-
static plow
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.
-
station
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.
-
STEG
See septic tank effluent gravity.
-
STEP
See septic tank effluent pump.
-
stepdown
A relief line plumbing configuration that raises the piping flow line elevation to achieve a specified ponding level in the trench before effluent is conveyed to the next trench.
-
storage lagoon
Lagoon where some form of wastewater is stored before it is either conveyed to another component for further processing or is reused.
-
stormwater
Runoff resulting from precipitation.
-
straight pipe
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.
-
structural ramp
Ramp built of steel or wood, usually used for vehicle access; ramps made of soil or rock are not considered structural ramps.
-
structureless
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).
-
sub-main line
Portion of the main line located after a flow splitter that carries a portion of flow to a spray dispersal field.
-
subangular blocky
-
submain
-
submerged flow constructed wetland system
constructed wetland in which wastewater passes through the component below the surface of the media.
-
submerged soil
Soil which is underwater or is freely seeping.
-
submersible pump
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.
-
subsoil
-
subsurface drain
Underground conduit used to collect and convey surface or groundwater.
-
subsurface drip field
Drip field designed and installed such that the drip tubing is located at least 6” below finished grade of native soil.
-
subsurface wastewater infiltration system (SWIS)
See soil treatment area (STA).
-
summit
A general term for the highest point of any landform remanant, hill, or mountain.
-
sump tank
Tank or pit that receives drainage of groundwater or runoff, stores it temporarily, and from which the discharge is pumped.
-
supply line
Piping between a source of effluent and the associated gravity-flow or pressure distribution system.
-
supply manifold
Manifold that allows effluent to be distributed to two or more laterals.
-
support system
Structure such as underpinning, bracing, or shoring, which provides support to an adjacent structure, underground installation, or the sides of an excavation.
-
surface diversion
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.
-
surface drip field
Drip field designed and installed such that the drip tubing is located at the finished grade of the soil surface.
-
surface runoff
-
surface water
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.
-
surge flow
Flow of effluent that occurs in a short enough period that it upsets the function of one or more components of the treatment train.
-
surge tank
See flow equalization tank.
-
surge volume
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.
-
surveying
Determining the dimensions and contour (or three-dimensional characteristics) of the earth’s surface by the measurement of distances, directions and elevations.
-
suspended growth
Treatment configuration wherein the microorganisms that provide treatment are maintained in suspension within a liquid; see also attached growth.
-
suspended growth process
Configuration wherein the microorganisms that provide treatment are maintained in suspension within a liquid; see also attached growth process.
This document was developed by NOWRA with funding from the U.S. Environmental Protection Agency Treatment Works Program 25-28 administered by the Rural Community Assistance Partnership Incorporated (RCAP).
