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Pressure
Pressure exerted backward; in a field of fluid flow, a pressure exerted
contrary to the pressure producing the main flow.
Backflow
A
reverse flow of water or other liquids into the water supply pipes,
caused by negative pressure in the pipes.
Bacteria
Single-celled organisms, free-living or parasitic, that break down the
wastes and bodies of dead organisms, making their components available
for reuse by other organisms.
Baseflow
Water
that, having infiltrated the soil surface, percolates to the ground
water table and moves laterally to reappear as surface runoff.
Basin
The
entire geographical area drained by a river and its tributaries.
Bay
An
indentation of a shoreline larger than a cove but smaller than a gulf.
Bedrock
The
solid rock that underlies all soil or other loose material; the rock
material that breaks down to eventually form soil.
Benthic zone
The
bottom of a body of water or in the bottom sediments.
An
agricultural practice that has been determined to be an effective,
practical means of preventing or reducing nonpoint source pollution.
Bicarbonates
A salt
of carbonic acid, having an HCO3 group, such as sodium bicarbonate.
Bioaccumulation
The
uptake of chemical substances from the environment or food, their
concentration and retention by organisms.
Bioavailability
The
availability of chemicals to potentially biodegradative microorganisms.
Biochemical
It
relates to the chemistry of living organisms and the changes that occur.
Biocide
Substances such as antibiotics, bacterialcides, or fungicides that are
capable of destroying living organisms.
Biodegradable
Able
to be broken down into basic compounds by micro-organisms.
Biodegradation
Transformation of a substance into new compounds through biochemical
reactions or the actions of microorganisms such as bacteria.
Biogas
The
gas produced from the anaerobic decomposition of organic material in a
landfill.
Biological Contaminants
Contamination caused by living organisms either microscopic or larger
animals, which can cause health effects.
Biological Control
The
use of organisms or viruses to control parasites, weeds, or other pests.
Biological Diversity
The
variety of life forms in a given area. Diversity can be categorized in
terms of the number of species, the variety in the area's plant and
animal communities, the genetic variability of the animals, or a
combination of these elements.
Biological Growth
The
growth of all organisms.
Biological Integrity
The
ability of an aquatic ecosystem to support and maintain a balanced,
adaptive community of organisms having a species composition, diversity,
and functional organization comparable to that of natural habitats
within a region.
Biological Oxidation
Decomposition of organic materials by microorganisms.
Biological Oxygen Demand
The
amount of oxygen required by aerobic biological processes to break down
the organic matter in water. BOD is a measure of the pollutional
strength of biodegradeable waste on dissolved oxygen in water.
Biomass
The
amount of living matter, in the form of organisms, present in a
particular habitat, usually expressed as weight per unit area.
Biosphere
The
part of the earth and its atmosphere in which living organisms exist or
that is capable of supporting life; (2) the living organisms and their
environment composing the biosphere.
Biota
The
animal and plant life of a region or period.
Biotic
Belonging to life and living organisms
Black
Ice
Thin,
new ice on fresh or salt water that appears dark in color because of its
transparency. Also refers to thin, transparent ice on road surfaces.
Black
Water
Surface water that is dark in color because it contains high levels of
colored organic acids such as tannic acid, or (2) domestic wastewater
that contains animal, human, or food wastes.
Bloom
A
visible abundance of microorganisms, generally referring to the
excessive growth of algae or cyanobacteria at the surface of a body of
water.
Blue-green Algae
Algae
that are often associated with problem blooms in lakes. Some produce
chemicals toxic to other organisms, including humans. They often form
floating scum as they die. Many can fix nitrogen (N2) from the air to
provide their own nutrient.
Bog
A
poorly drained, wet area with very acidic (ph 4.0 or less), peaty soil.
Bogs receive little or no ground water influence and support vegetation
such as sedges, mosses, orchids and black spruce.
Boulder
A very
large piece of rock.
Bound
Water
Water
which has become adsorbed to the surfaces of solid particles or grains.
Under natural conditions, this water is viscous like and immobile but
might not have lost its electrolytic properties. See also adsorption and
water wet.
Brackish Water
Having
a salinity between that of fresh and sea water.
Brackish Ice
Ice
formed from brackish water.
Brine
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