Environmental Engineering Reference
In-Depth Information
Species:
The basic category of biological classification intended to designate a sin-
gle kind of animal or plant. Any variation among the individuals may be
regarded as not affecting the essential sameness that distinguishes them from
all other organisms.
Spent liquor:
The liquid residue left after an industrial process; it can be a component
of waste materials used as fuel.
Spent sulfite liquor:
End-product of pulp and paper manufacturing processes that
contains lignins and has a high moisture content; it is often reused in recovery
boilers and is similar to black liquor.
Spinner survey:
The use of a device with a small propeller that spins when fluid
passes in order to measure fluid flow in a wellbore. The device is passed up
and down the well, continuously measuring flow to establish where and how
much fluid enters or leaves the wellbore at various depths.
Spinning reserve:
A reserve of generation capacity, where generators are kept online,
but at idle, in anticipation of an unexpected increase in demand or decrease
in supply.
Start-up speed:
The windspeed at which a rotor begins to rotate.
Stimulation:
A treatment performed to restore or enhance the productivity of a well.
Stimulation treatments fall into two main groups: hydraulic fracturing treat-
ments and matrix treatments.
Stormwater:
A term used to describe water runoff generated when precipitation from
rain and snowmelt events flows over land or imperious surfaces.
Stress:
The forces acting on rock. In the subsurface, the greatest force or stress is gen-
erally vertical caused by the weight of overlying rock.
Structural discontinuity:
A discontinuity of the rock fabric that can be a fracture,
fault, intrusion, or differing adjacent rock type.
Submersible sump:
Pump with both the pumping mechanism and a driving electric
motor suspended together at depth in the well.
Subsidence:
The sinking of an area of the Earth's crust due to fluid withdrawal and
pressure decline.
Succession:
The natural, sequential change in species composition of a community in
a given area.
Sulfur dioxide (SO
2
):
A toxic, irritating, colorless gas soluble in water, alcohol, and
ether. Used as a chemical intermediate, in paper pulping and ore refining, and
as a solvent.
Surface water:
All waters whose surface is naturally exposed to the atmosphere, or
wells or other collectors directly influenced by surface water.
Swell direction (SwD):
The direction that the swells are coming from. Swells are
waves not produced by the local wind and come in at a higher period (longer
wavelength) than waves produced by the local wind. Direction is given on a
16-point compass scale.
Swell height (SwH):
The estimated average height of the highest one-third of the swells.
It is estimated by determining how the wave energy is distributed among
various periods (frequencies) and if a separate swell energy peak exists, and
then picking a frequency to separate swell and wind-waves. The swell height
is calculated from the wave energies below the separation frequency.
