Wastewater and its characteristics:
BOD (denoting BIOCHEMICAL OXYGEN DEMAND)
The quantity of oxygen utilized in the biochemical oxidation
of organic matter under standard laboratory procedure in five days
at 20° C., expressed in milligrams per liter.
FLOATABLE OIL
Oil, fat, or grease in a physical state such that it will
separate by gravity from wastewater by treatment in an approved pretreatment
facility. A wastewater shall be considered free of floatable oil if
it is properly pretreated and the wastewater does not interfere with
the collection system.
GARBAGE
Solid wastes from the domestic and commercial preparation,
cooking, and dispensing of food and from the handling, storage and
sale of produce.
INDUSTRIAL WASTE
Any solid, liquid or gaseous substance discharged, permitted
to flow or escaping from any industrial, manufacturing, commercial
or business establishment or process or from the development, recovery
or processing of any natural resource as distinct from sanitary sewage.
MAJOR CONTRIBUTING INDUSTRY
An industrial user of the publicly owned treatment works
that:
(1)
Has a flow of 50,000 gallons or more per average work day; or
(2)
Has a flow greater than 10% of the flow carried by the municipal
system receiving the waste; or
(3)
Has in its waste a toxic pollutant in toxic amounts as defined
in standards issued under Section 307(a) of the Federal Act; or
(4)
Is found by the permit issuance authority, in connection with
the issuance of the NPDES permit to the publicly owned treatment works
receiving the waste, to have significant impact, either singly or
in combination with other contributing industries, on the treatment
works or upon the quality of effluent from the treatment works.
MILLIGRAMS PER LITER
A unit of the concentration of water or wastewater constituent.
It is 0.001 gram of the constituent in 1,000 ml of water. It has replaced
the unit formerly used, commonly parts per million, to which it is
approximately equivalent, in reporting the results of water and wastewater
analysis.
pH
The logarithm (base 10) of the reciprocal of the hydrogen
ion concentration expressed by one of the procedures outlined in Standard
Methods.
POPULATION EQUIVALENT
Used to evaluate the impact of industrial or other waste
on a treatment works or stream. One population equivalent is 100 gallons
of sewage per day, containing 0.22 pounds of BOD and 0.22 pounds of
suspended solids.
PPM
Parts per million by weight.
PROPERLY SHREDDED GARBAGE
The wastes from the preparation, cooking, and dispensing
of food that have been shredded to such a degree that all particles
will be carried freely under the flow conditions normally prevailing
in public sewers, and no particle greater than 1/2 inch (1.27 centimeters)
in any dimension.
SEWAGE
Used interchangeably with "wastewater."
SLUG
Any discharge of water, sewage or industrial waste which
in concentration of any given constituent or in quantity of flow exceeds
for any period of duration longer than 15 minutes more than five times
the average twenty-four-hour concentration or flows during normal
operation.
STANDARD METHODS
The examination and analytical procedures set forth in the
most recent edition of "Standard Methods for the Examination of Water
and Wastewater" published jointly by the American Public Health Association,
the American Water Works Association and the Water Pollution Control
Federation.
SUSPENDED SOLIDS
Solids that either float on the surface of or are in suspension
in water, sewage, or industrial waste, and which are removable by
a laboratory filtration device. Quantitative determination of suspended
solids shall be made in accordance with procedures set forth in Standard
Methods.
UNPOLLUTED WATER
Water of quality equal to or better than the effluent criteria
in effect or water that would not cause violation of receiving water
quality standards and would not be benefitted by discharged to the
sanitary sewers and wastewater treatment facilities provided.
WASTEWATER
The spent water of a community. From this standpoint, of
course, it may be a combination of the liquid and water-carried wastes
from residences, commercial buildings, industrial plants, and institutions,
together with any groundwater, surface water, and stormwater that
may be present.