Glossary
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Abandoned Well |
A
well whose use has been
permanently discontinued or
which is in a state of such
disrepair that it cannot be used
for its intended purpose. |
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Abatement |
Reducing the degree or intensity
of, or eliminating, pollution. |
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Abiotic |
Not
relating to living things, not
alive. |
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Absorbance |
A
measure of the decrease in
incident light passing through a
sample into a detector. It is
defined mathematically as:
A = I (solvent) = log
Io
I (solution) I
where I = radiation intensity |
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Absorbed Dose |
The
amount of a chemical that enters
the body of an exposed organism.
Equal to intake multiplied by an
absorption factor. |
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Absorption |
1)
The process by which one
substance is taken into the body
of another substance. 2) The
penetration of molecules or ions
of one or more substances (gas,
liquid or solid) into the
interior of another substance.
For example, in hydrated
bentonite (a type of clay), the
water that is held between the
mica-like layers (held within
the clay) is the result of
absorption. |
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Accelerated Operable Unit (AOU) |
An
action which prevents, controls
or responds to a release or
threatened release of hazardous
substances, pollutants, and
contaminants where prompt action
is necessary but a response
under removal authorities is not
appropriate or desirable. The
purpose of an AOU is to allow
the remedial action for that
Operable Unit to proceed prior
to completion of the final
Record of Decision (ROD) for the
total remedial action. AOUs are
particularly appropriate where
the size and complexity of the
total remedial action would
seriously delay implementation
of independent parts of the
action. AOUs will only proceed
after complying with applicable
procedures in the NCP. It is not
intended that AOUs diminish the
requirements for, delay the
conduct of, or conflict with the
total remedial action. |
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Accident Site |
The
location of an unexpected
occurrence, failure or loss,
either at a plant or along a
transportation route, resulting
in a release of hazardous
materials. |
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Accuracy |
The
degree of agreement between a
measured value and a true,
expected value. |
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Acetone |
A
colorless, volatile liquid with
a sweet odor. It is considered
the least toxic solvent in
industry. It can occur
naturally. It is used in the
production of lubricating oils,
chloroform, pharmaceuticals,
pesticides, paints, varnishes
and lacquers. If present in
water, it is more likely to
volatilize or biodegrade before
bioaccumulating or adsorbing to
sediments. Acetone will also
readily volatilize and
biodegrade in soil. It is also a
common laboratory contaminant,
so its presence in a sample does
not always indicate its presence
in the environment. Synonyms -
Dimethylketone and 2-propanone. |
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Acid |
An
inorganic or organic compound
that 1) reacts with metals to
yield hydrogen; 2) reacts with a
base to form a salt; 3)
dissociates in water to yield
hydrogen ions; 4) has a pH of
less than 7.0; 5) neutralizes
bases or alkalis; and 6) turns
litmus paper red. All acids
contain hydrogen. They are
corrosive to tissue and should
be handled with care.
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Acid Neutralizing Capacity |
A
measure of the ability of water
or soil to resist changes in pH. |
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Acidic |
The
condition of water or soil that
contains a sufficient amount of
acid substances to lower the pH
below 7.0 |
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Action Level (AL) |
1)
In the Superfund program, the
existence of a contaminant
concentration in the environment
high enough to warrant action or
trigger a response under SARA
and the NCP. 2) Regulatory
levels recommended by EPA for
enforcement by FDA and USDA when
pesticide residues occur in food
or feed commodities for reasons
other than the direct
application of the pesticide. As
opposed to "tolerances" which
are established for residues
occurring as a direct result of
proper usage, action levels are
set for inadvertent residues
resulting from previous legal
use or accidental contamination.
3) Unless otherwise specified in
a NAVOSH standard, one-half the
relevant Permissible Exposure
Limit (PEL) or Threshold Limit
Value (TLV). See Tolerances. |
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Activated Carbon |
A
highly adsorbent form of carbon
used to remove odors and toxic
substances from liquid or
gaseous emissions. In waste
treatment it is used to remove
dissolved organic matter from
waste water. It is also used in
motor vehicle evaporative
control systems. |
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Acute Exposure |
A
single exposure to a toxic
substance which results in
severe biological harm or death.
Acute exposures are usually
characterized as lasting no
longer than a day, as compared
to longer, continuing exposure
over a period of time. |
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Acute Toxicity |
The
ability of a substance to cause
poisonous effects resulting in
severe biological harm or death
soon after a single exposure or
dose, usually within 24 hours.
Also, any severe poisonous
effect resulting from a single
short-term exposure to a toxic
substance. See Chronic Toxicity,
Toxicity. |
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Adaptation |
Changes in an organism's
structure or habits that help it
adjust to its surroundings. |
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Adjacent Property |
Either those properties
contiguous to the boundaries of
the property being surveyed or
other nearby properties. |
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Administrative Order |
A
legal document signed by EPA
directing an individual,
business, or other entity to
take corrective action or
refrain from an activity. It
describes the violations and
actions to be taken, and can be
enforced in court. Such orders
may be issued, for example, as a
result of an administrative
complaint whereby the respondent
is ordered to pay a penalty for
violations of a statute. |
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Administrative Order On Consent |
A
legal agreement signed by EPA
and an individual, business, or
other entity through which the
violator agrees to pay for
correction of violations, take
the required corrective or
cleanup actions, or refrain from
an activity. It describes the
actions to be taken, may be
subject to a comment period,
applies to civil actions, and
can be enforced in court. |
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Administrative Record (AR) |
A
compilation of information
established for all CERCLA sites
made available to the public at
the start of the Remedial
Investigation (RI) for remedial
actions, or at the time of
Engineering Evaluation/Cost
Analysis (EE/CA) for removal
actions. Information in the
Administrative Record supports
the selected remedy for remedial
actions and removal actions. |
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Administrative Record File (ARF) |
1)
Refers to documents, as they are
being established and
maintained. Until a response
action decision has been
selected, there is no complete
administrative record for that
decision. Thus, to avoid
creating the impression that the
record is complete at any time
prior to the final selection
decision, the set of documents
is referred to as the ARF rather
than the AR. 2) A file that
contains all information used in
order to make decisions on the
selection of a response action
under CERCLA. Available for
public review and comment. |
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Adsorption |
The
process by which a gas, vapor,
dissolved material or very small
particle adheres to the surface
of a solid due to chemical or
physical forces; the attraction
and adhesion of ions from an
aqueous solution to the solid
soil or rock surfaces with which
they are in contact. |
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Advection |
The
transport of dissolved
contaminants by the bulk
movement of groundwater flow;
the main process driving the
movement of dissolved
contaminants. |
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Advisory |
A
non-regulatory document that
communicates risk information to
those who may have to make risk
management decisions. |
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Aeration |
A
process of supplying or
introducing air/oxygen into a
medium which promotes biological
degradation of organic matter in
water. The process may be
passive (as when waste is
exposed to air), or active (as
when a mixing or bubbling device
introduces the air). |
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Aeration Tank |
A
chamber used to inject air into
water. |
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Aerobe |
Bacteria that use oxygen as an
electron acceptor.
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Aerobic |
Life or processes that require,
or are not destroyed by, the
presence of oxygen. See
Anaerobic. |
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Aerobic Treatment |
Process by which microbes
decompose complex organic
compounds in the presence of
oxygen and use the liberated
energy for reproduction and
growth. Such processes include
extended aeration, trickling
filtration, and rotating
biological contactors. |
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Affected Public |
The
people who live and/or work near
a hazardous waste site. |
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Affinity |
A
chemical attraction or force
that causes the atoms of certain
elements or compounds to combine
with atoms of another element or
compound and remain in the
combined state. |
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Air Changes per Hour (ACH)
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The
movement of a volume of air in a
given period of time; if a house
has one air change per hour, it
means that all of the air in the
house will be replaced in a
one-hour period. |
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Air Purification Devices
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Respirators or filtration
devices which remove particulate
matter, gases, or vapors from
the atmosphere. These devices
range from full face piece, dual
cartridge masks with eye
protection, to half-mask face
piece, mounted cartridges with
no eye protection. |
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Air Sparging |
General term for the technology
of introducing gases, usually
air, beneath the water table to
promote site remediation. Air
sparging can be divided into two
distinct processes: in-well
aeration and air injection.
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Air Stripping |
A
treatment system that removes
volatile organic compounds
(VOCs) from contaminated
groundwater or surface water by
forcing an airstream through the
water and causing the compounds
to volatilize to the airsteam,
enabling separation of the
compounds from the water and
possible further treatment of
the airstream. |
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Algae |
Simple rootless plants that grow
in sunlit waters, on rocks and
in soil, in proportion to the
amount of available nutrients.
They can affect water quality
adversely by lowering the
dissolved oxygen in the water.
They are food for fish and small
aquatic animals. |
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Aliphatic Hydrocarbon |
A
compound built from carbon and
hydrogen atoms joined in a
linear chain. Petroleum products
are composed primarily of
aliphatic hydrocarbons. |
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Aliquot |
A
measured portion of a sample
taken for analysis.
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Alkali |
Any
compound having highly basic
properties; i.e., one that
readily ionizes in aqueous
solution to yield OH anions,
with a pH above 7.0, and turns
litmus paper blue. Examples are
oxides and hydroxides of certain
metals belonging to group IA of
the periodic table (Li, Na, K,
Rb, Cs, Fr). Ammonia and amines
may also be alkaline. Alkalis
are caustic and dissolve tissue.
Treat alkali burns by quickly
washing with large amounts of
water for at least 15 minutes.
Common commercial alkalis are
sodium carbonate (soda ash),
caustic soda and caustic potash,
lime, lye, waterglass, regular
mortar, portland cement, and
bicarbonate of soda. |
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Alkaline |
The
condition of water or soil which
contains a sufficient amount of
alkali substances to raise the
pH above 7.0. |
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Alkalinity |
The
capacity of water to neutralize
acids. |
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Alluvial |
Relating to mud and/or sand
deposited by flowing water.
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Alternative Fuels |
Substitutes for traditional
liquid, oil-derived motor
vehicle fuels like gasoline and
diesel. Includes methanol,
ethanol, compressed natural gas,
and others. |
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Alternative Technology |
An
approach that aims to use
resources efficiently or to
substitute resources in order to
do minimum damage to the
environment. This approach
permits a large degree of
personal user control over the
technology.
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Aluminum (Al) |
A
light ductile metal that is easy
to weld. It is a good conductor
of heat and electricity. When it
is exposed to air, it creates a
protective film resistant to
corrosion. It is used in alloys
with copper, zinc, manganese and
magnesium. It is a very
versatile metal and so has a
wide variety of uses: packaging
materials, utensils,
auto-bodies, airplanes, building
materials, electrical
conductors, explosives,
fireworks, abrasives, cosmetics,
paints, and even food additives.
It is a natural component in
soil, water, and air. Inhalation
of the fine powder can lead to
pulmonary fibrosis. |
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Ambient |
Usual or natural surrounding
conditions, e.g., ambient
temperature - the natural,
uninfluenced temperature of the
surroundings.
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Anabolism |
The
process whereby energy is used
to build organic compounds, such
as enzymes and nucleic acids,
that are necessary for life
functions. |
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Anadromous |
Fish that spend their adult life
in the sea but swim upriver to
freshwater spawning grounds to
reproduce. |
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Anaerobic |
A
life or process that occurs in,
or is not destroyed by, the
absence of oxygen. |
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Anaerobic Decomposition
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Reduction of the net energy
level and change in chemical
composition of organic matter
caused by microorganisms in an
oxygen free environment. |
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Analytes |
The
chemicals for which a sample is
analyzed.
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Analytical Method |
Defines the sample preparation
and instrumentation procedures
or steps that must be performed
to estimate the quantity of
analyte in a sample. |
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Animal Studies |
Investigations using animals as
surrogates for humans with the
expectation that the results are
pertinent to humans. |
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Anion Exchange Capacity
|
A
quantitative measure of surface
charge of an anion reported in
equivalents of exchangeable ions
per unit weight of the solid.
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Anisotropic / Anisotropy
|
Having different properties in
different directions. See
isotropic. |
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Antagonism |
1)
Interference or inhibition of
the effect of one chemical by
the action of another. 2)
An interaction of two or more
chemicals which results in an
effect that is less than the sum
of their effects taken
independently. |
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Anthropogenic |
Of
or relating to humans or the era
of human life. Man-made. |
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Anthropomorphic |
Ascribing human motivation,
characteristics, or behavior to
inanimate objects, animals, or
natural phenomena. |
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Anti-Degradation Clause
|
Part of federal air and water
quality requirements prohibiting
deterioration where pollution
levels are above the legal
limit.
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Applicable or Relevant and
Appropriate Requirement (ARAR)
|
Requirements, including cleanup
standards, standards of control
and other substantive
environmental protection
requirements and criteria, for
hazardous substances as
specified under Federal and
state laws and regulations, that
must be met when complying with
CERCLA and SARA. |
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Aqueous |
Something made up of, similar
to, or containing water; watery.
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Aquiclude |
A
saturated geologic unit that is
incapable of transmitting
significant quantities of water
under ordinary hydraulic
gradients.
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Aquifer |
A
saturated, permeable geologic
formation or structure that is
capable of yielding water in
usable quantities under ordinary
hydraulic gradients. |
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Aquitard |
The
less permeable beds in a
stratigraphic sequence; beds may
be permeable enough to transmit
water in quantities that are
significant in the study of
regional groundwater flow or
environmental contamination, but
their permeability is not
sufficient to allow completion
of production wells within them.
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Area of Concern
(AOC) |
A
discrete area of contamination
or suspected contamination that
is in the PA/SI (or RFA) phase
and that has not been entered
into the DOD RMIS database.
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Aromatic |
A
class of hydrocarbons consisting
of cyclic conjugate carbon
atoms, such as benzene or
toluene, commonly added to
gasoline in order to increase
octane. Some aromatics are
toxic. |
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Arsenic (Ar) |
A
metalloid occurring naturally in
the earth's crust and fossil
fuels. It can be released into
the environment during
combustion of fossil fuels
containing arsenic. It is used
in the production of glass,
enamels, ceramics, oil, cloth,
linoleum, electrical
semiconductors, pigments,
fireworks, pesticides,
fungicides, veterinary
pharmaceuticals, and wood
preservatives. Soluble forms of
arsenic can be quite mobile,
while less soluble forms tend to
adsorb to sediments and soils.
It is a known human carcinogen,
and bioaccumulates to toxic
levels. |
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Artesian Aquifer |
A
confined aquifer in which
groundwater rises in a well
above the point at which it is
naturally found in the aquifer,
due to artesian pressure. |
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Asbestos |
A
mineral fiber that can pollute
air or water and cause cancer or
asbestosis when inhaled. EPA has
banned or severely restricted
its use in manufacturing and
construction. |
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Ash |
The
mineral content of a product
remaining after complete
combustion. |
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Assessment Endpoint |
Environmental characteristics,
which, if they were found to be
significantly affected, would
indicate a need for remediation
(e.g., decrease in sports
fisheries). |
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Assimilative Capacity |
The
capacity of a natural body of
water to receive wastewaters or
toxic materials without
deleterious effects and without
damage to aquatic life or humans
who consume the water. |
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Atmosphere-Supplying Devices
|
Respiratory protection devices
coupled to an air source. The
two types are Self-Contained
Breathing Apparatus (SCBA) and
supplied air respirators
(airline). |
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Attenuation |
The
process by which a compound is
reduced in concentration with
distance and time through
absorption, adsorption,
degradation, dilution,
diffusion, dispersion, and/or
chemical or biological
transformation. |
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Autochthonous |
A
term applied to rocks of which
the dominant constituents have
been formed in the natural or
original position as opposed to
prior erosion and disposition.
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Autotrophic |
An
organism that produces food from
inorganic substances, e.g.
photosynthetic plants. |
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Back to
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B
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Background Correction
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In
data analysis, a technique to
compensate for variable
background contribution to the
instrument signal and the
determination of trace metals.
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Background Level |
1)
Naturally occurring levels:
ambient concentrations of
chemicals present in the
environment that have not been
influenced by humans; 2)
Anthropogenic levels:
concentrations of chemicals that
are present in the environment
due to human-made, non-site
sources. |
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Backwashing |
Reversing the flow of water back
through the filter media to
remove the entrapped solids.
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Bacteria |
(Singular: bacterium)
Microscopic living organisms
ubiquitous in the environment,
that can aid in pollution
control by metabolizing organic
matter in sewage, oil spills or
other pollutants. However,
bacteria in soil, water or air
can also cause human, animal and
plant health problems.
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Baghouse Filter |
Large fabric bag, usually made
of glass fibers, used to
eliminate intermediate and large
(greater than 20 microns in
diameter) particles. This device
operates like the bag of an
electric vacuum cleaner, passing
the air and smaller particles
while entrapping the larger
ones.
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Bailer |
A
long pipe with a valve at the
lower end, used to remove slurry
from the bottom or side of a
well as it is being drilled or
to obtain a water sample from a
developed well. |
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Barium (Ba) |
The
heaviest of the stable alkaline
earths, it is a soft,
silver-grey metal. It is used in
various alloys, paints, soap,
paper, rubber, ceramics, glass,
insecticides, oil and gas well
drilling muds, fireworks,
lubricating oil, and steel
hardening. It is naturally
abundant in nature and is found
in plant and animal tissue.
Ingestion of barium or some of
its compounds can cause muscular
problems, and it can accumulate
in the skeleton. |
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Barrier Coating(s) |
A
layer of a material that
obstructs or prevents passage of
something through a surface that
is to be protected, e.g. grout,
caulk, or various sealing
compounds; sometimes used with
polyurethane membranes to
prevent corrosion or oxidation
of metal surfaces, chemical
impacts on various materials,
or, for example, to prevent
radon infiltration through
walls, cracks, or joints in a
house. |
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Base |
Substances that (usually)
liberate OH anions when
dissolved in water. Bases 1)
react with acids to form salts;
2) have a pH greater than 7.0;
3) turn litmus paper blue; and
4) may be corrosive to tissue. A
strong base is called alkaline
or caustic. Examples are lye and
DRANO.
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Base Neutral Acid Compound (BNA)
|
See
Semi-Volatile Organic Compound
(SVOC). |
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Base Realignment And Closure
(BRAC) |
Refers to policy, procedures,
authorities, and
responsibilities for closing or
realigning military
installations across the
Department of Defense. Includes
environmental restoration
activities. |
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Baseline Risk Assessment
|
An
analysis of the potential
adverse health effects (current
or future) caused by contaminant
releases from a site in the
absence of any actions to
control or mitigate these
releases. According to EPA, the
baseline risk assessment can be
used to determine whether: 1) A
release or threatened release
poses an unacceptable risk to
human health or the environment
that warrants remedial action,
and 2) A site presents an
imminent and substantial
endangerment. The primary
purpose is to provide risk
managers with an understanding
of the actual and potential
risks to human health and the
environment posed by the site
and the uncertainties associated
with the assessment. |
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Bed Load |
Sediment particles resting on or
near the channel bottom that are
pushed or rolled along by the
flow of water. |
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Bedrock |
Any
solid rocks exposed at the
surface or overlain by
unconsolidated materials. |
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Bench-scale Tests |
Laboratory testing of potential
cleanup technologies.
Contaminated media from the site
are generally used to determine
the applicability of a
technology to a specific site.
See Pilot Tests and Treatability
Studies. |
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Benthic Organism (Benthos)
|
A
form of aquatic plant or animal
life that is found on or near
the bottom of a stream, lake,
ocean or other water body. |
|
Benthic Region |
The
bottom layer of a body of water.
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Bentonite |
Clay made of decomposed volcanic
ash which is used to seal wells
(hole plug). |
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Beryllium (Be) |
A
greyish-white metal occurring
naturally in certain rocks,
soils and volcanic dust. A major
emission source to the
environment is through the fly
ash from combustion of coal and
fuel oil, which can contain the
metal. It is used in nuclear
reactors, radio and television
tubes, fluorescent tubes and
powders. It is discharged by
machine shops, ceramic and
propellant plants, and
foundries. In the environment,
it ultimately accumulates in
sediments. Beryllium can cause
severe dermatitis problems and
can be toxic if inhaled. It is a
Group B2, animal carcinogen
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Best Demonstrated Available
Technology (BDAT) |
As
identified by EPA, the most
effective, commercially
available means of treating
specific types of hazardous
waste. The BDATs may change with
advances in treatment
technologies. |
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Best Management Practice (BMP)
|
Methods that have been
determined to be the most
effective, practical means of
preventing or reducing pollution
from nonpoint sources. |
|
Bias |
Consistent deviation of measured
values from the true value,
caused by systematic errors in a
procedure. |
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Bicarbonates |
Metal + HCO3, e.g.
NaHCO3. Can raise the
pH to a high concentration which
may be corrosive. |
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Bioaccumulants |
Substances that increase in
concentration in living
organisms as they take in
contaminated air, water, or food
because the substances are very
slowly metabolized or excreted.
See Biological Magnification.
|
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Bioassay |
Study of living organisms to
measure the effect of a
substance, factor, or condition
by comparing before-and-after
exposure or other data. |
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Bioaugmentation |
The
addition of microbe cultures to
groundwater or soil to enhance
biodegradation. |
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Bioavailability |
A
general term to describe the
accessibility of contaminants to
ecological populations.
Bioavailability consists of: 1)
a physical aspect related to
phase distribution and mass
transfer, and 2) a physiological
aspect related to the
suitability of the contaminant
as a substrate. |
|
Biobarrier |
An
In Situ remediation technology
consisting of a trench filled
with biological medium to
encourage the growth of bacteria
capable of degrading
contaminants. |
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Biochemical Oxygen Demand (BOD)
|
A
measure of the amount of oxygen
consumed in the biological
processes that break down
organic matter in water. The
greater the BOD, the greater the
degree of pollution. |
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Bioconcentration |
The
accumulation of a chemical in
tissues of an organism (such as
a fish) to levels greater than
in the surrounding medium in
which the organism lives. |
|
Bioconcentration Factor (BCF)
|
Provides a measure of the extent
of chemical partitioning at
equilibrium between biological
medium such as fish tissue or
plant tissue and an external
medium such as water. The higher
the BCF, the greater the
accumulation in living tissue is
likely to be. |
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Biodegradable |
Capable of decomposing under
natural conditions.
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Biodegradation |
1)
The reduction in concentration
of a chemical or physical agent
through naturally occurring
microbial activity. 2) The
process of an organic molecule
becoming transformed by
biological means. |
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Biodegradation Rate |
The
mass of contaminant metabolized
by microorganisms per unit time.
In soil contamination this is
normalized to the mass of soil
and usually is expressed as mg
contaminant degraded/kg soil/day
(mg/kg/day).
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Biodiversity |
Refers to the variety and
variability among living
organisms and the ecological
complexes in which they occur.
Diversity can be defined as the
number of different items and
their relative frequencies. For
biological diversity, these
items are organized at many
levels, ranging from complete
ecosystems to the biochemical
structures that are the
molecular basis of heredity.
Thus, the term encompasses
different ecosystem, species,
and genes.
|
|
Biological Additive |
Microbiological cultures,
enzymes, or nutrient additives
that are deliberately introduced
into a discharge for the
specific purpose of encouraging
biodegradation to mitigate the
effects of the discharge.
|
|
Biological Magnification
|
Refers to the process whereby
certain substances such as
pesticides or heavy metals move
up the food chain, work their
way into rivers or lakes, and
are eaten by aquatic organisms
such as fish, which in turn are
eaten by large birds, animals or
humans. The substances become
concentrated in tissues or
internal organs as they move up
the chain. See Bioaccumulants.
|
|
Biological Oxidation |
Decomposition of complex organic
materials by microorganisms.
Occurs in self-purification of
water bodies and in activated
sludge wastewater treatment.
|
|
Biological Oxygen Demand (BOD)
|
An
indirect measure of the
concentration of biologically
degradable material present in
organic wastes. It usually
reflects the amount of oxygen
consumed in five days by
biological processes breaking
down organic waste. |
|
Biological Treatment |
A
treatment technology that uses
bacteria to consume waste. |
|
Biomass |
All
of the living material in a
given area; often refers to
vegetation. |
|
Biome |
The
entire community of living
organisms in a single major
ecological area. See Biotic
Community. |
|
Biomonitoring |
1)
The use of living organisms to
test the suitability of
effluents for discharge into
receiving waters and to test the
quality of such waters
downstream from the discharge.
2) Analysis of blood, urine,
tissues, etc., to measure
chemical exposure in humans or
animals.
|
|
Biopile |
Soil pile constructed to allow
aerobic bioremediation by
aeration, possibly supplemented
with water and nutrients. |
|
Bioreactor |
A
container or area in which a
biological reaction or
biological activity takes place.
|
|
Bioreclamation |
The
process of making a contaminated
site usable again through
biological processes. |
|
Bioremediation |
1)
Use of living organisms to clean
up oil spills or remove other
pollutants from soil,
groundwater, or wastewater. 2)
Use of organisms such as
non-harmful insects to remove
agricultural pests or counteract
diseases of trees, plants, and
garden soil. |
|
Bioslurping |
A
technology application that
teams vacuum-assisted
free-product recovery with
bioventing to simultaneously
recover free product and
remediate the vadose zone. |
|
Biosphere |
The
portion of Earth and its
atmosphere that can support
life. |
|
Biota |
The
animal and plant life of a given
region.
|
|
Biotechnology |
Techniques that use living
organisms or parts of organisms
to produce a variety of products
(from medicines to industrial
enzymes) to improve plants or
animals or to develop
microorganisms to remove toxic
compounds from bodies of water,
or act as pesticides. |
|
Biotic Community |
A
naturally occurring assemblage
of plants and animals that live
in the same environment and are
mutually sustaining and
interdependent. See Biome. |
|
Biotransformation |
Conversion of a substance into
other compounds by organisms;
includes biodegradation. |
|
Bioventing |
The
process of aerating vadose zone
soils by means of installed
vents to stimulate in situ
biological activity and optimize
biodegradation of organic
compounds with some
volatilization occurring.
|
|
Blank |
An
artificial sample designed to
monitor the introduction of
artifacts into the sampling and
analytical process. For aqueous
samples, reagent water is used
as a blank matrix; however, a
universal blank matrix does not
exist for solid samples, but
sometimes clean sand is used as
a blank matrix. The blank is
taken through all appropriate
steps of the process. A reagent
blank is an aliquot of
analyte-free water or solvent
analyzed with the analytical
batch. Field blanks are aliquots
of analyte-free water or
solvents brought to the field in
sealed containers and
transported back to the
laboratory with the sample
containers. Trip blanks and
equipment blanks are two
specific types of field blanks.
Trip blanks are not opened in
the field. They are used to
monitor sample contamination
originating from transport,
shipping, and site conditions.
Equipment blanks are opened in
the field and the contents
poured over or through the
sampling equipment, collected in
a sample container, and returned
to the laboratory as a sample.
Equipment blanks monitor
sampling device cleanliness and
decontamination effectiveness.
|
|
Blood Borne Pathogens |
Pathogenic microorganisms that
are present in human blood and
can cause diseases in humans.
These pathogens include
hepatitis B virus (HBV) and
human immunodeficiency virus
(HIV). |
|
Bloom |
A
proliferation of algae and/or
higher aquatic plants in a body
of water; often related to
pollution, especially when
pollutants accelerate growth.
|
|
Blower |
A
unit of rotating mechanical
equipment used to increase the
pressure in a gas stream and
providing a total pressure rise
of more than 4 inches of water
and less than 14.7 psi. |
|
Boiling Point (BP) |
The
temperature at which a liquid
changes its phase to a vapor or
gas. This is the temperature at
which a liquid’s vapor pressure
is equal to the surrounding
atmospheric pressure, so the
liquid rapidly volatilizes.
|
|
Boom |
A
floating device used to contain
oil on a body of water. |
|
Bottom Ash |
The
non-airborne combustion residue
from burning pulverized coal in
a boiler which falls to the
bottom of the boiler and is
removed mechanically. Bottom Ash
is a concentration of the
non-combustible materials, which
may include toxic compounds.
|
|
BRAC Cleanup Plan (BCP)
|
The
road map for expeditious cleanup
of military facilities necessary
to facilitate conveyance of
property to communities for
redevelopment. |
|
BRAC Environmental Coordinator
(BEC) |
The
DOD representative on the Base
Closure Team; has responsibility
and implementation authorities
for environmental cleanup
programs related to the transfer
of the installation's real
property. |
|
BRAC Environmental Funding
|
Includes all NAVFAC
centrally-managed environmental
projects, except NEPA, that are
funded through the BRAC account
such as environmental studies,
clean up, compliance, and
restoration. For Marine Corps
installations, it includes
funding for only restoration
work. |
|
Brackish |
Mixed fresh and salt water.
|
|
Brine Mud |
Waste material, often associated
with well-drilling or mining,
composed of mineral salts or
other inorganic compounds. |
|
Bromine (Br) |
A
halogen that can substitute for
hydrogen in many organic
compounds, generally making the
resultant compound more toxic.
|
|
Buffer |
A
substance that reduces the
change in pH that would
otherwise be produced by adding
acids or bases to a solution. A
pH stabilizer.
|
|
By-product |
Material, other than the
principal product, generated as
a consequence of an industrial
process. |
|
Back to
Top |
|
|
C
|
|
|
Cadmium (Cd) |
A
soft metal used in
electroplating, pigments,
plastic stabilizers, batteries,
fusible alloys, soft solder, and
solder for aluminum. Pollution
sources include smelter fumes
and dust, some incineration
products, fertilizer, municipal
wastewater and sludge
discharges. It is also an
industrial byproduct of the
manufacturing of zinc, copper
and lead. Its mobility depends
on the pH and redox state of the
local environment. It can be
adsorbed to sediments and soils
or relatively soluble in surface
water or groundwater depending
on the conditions.
Bioaccumulation in the
environment is a concern.
Ingestion can cause
gastrointestinal problems, and
inhalation can cause lung
problems. |
|
Calcium (Ca) |
An
alkaline earth metal that is
very abundant in the
environment. Readily forms salts
with various metals and
halogens. When present in water,
it can indicate salinity and
alkalinity. Contributes to hard
water when present in high
concentrations. It is an
essential nutrient for animals
and humans. Not generally
considered toxic. |
|
Calibration |
The
establishment of an analytical
curve based on the absorbance,
emission intensity, or other
measured characteristic of known
standards. The calibration
standards must be prepared using
the same type of acid or
concentration of acids as used
in the sample preparation, i.e.,
the same matrix. |
|
Calibration Blank |
Usually an organic or aqueous
solution that is as free of
analyte as possible and prepared
with the same volume of chemical
reagents used in the preparation
of calibration standards and
diluted to the appropriate
volume with the same solvent
(water or organic). The
calibration blank is used to
give the null reading for the
instrument response versus
concentration calibration curve.
One calibration blank should be
analyzed with each analytical
batch or every method-specified
number of samples, whichever is
more frequent. |
|
Calibration Check |
Verification of the ratio of
instrument response to analyte
amount, a calibration check is
done by analyzing for analyte
standards in an appropriate
solvent. Calibration check
solutions are made from a stock
solution which is different from
the stock used to prepare
standards. |
|
Calibration Standards |
A
series of known standard
solutions used by the analyst
for calibration of the
instrument (i.e. preparation of
the analytical curve). |
|
Cancer |
The
development of a malignant tumor
or abnormal formation of tissue.
|
|
Cancer Risk |
Incremental probability of an
individual developing cancer
over a lifetime as a result of
exposure to a chemical. |
|
Cap |
A
layer of clay, or other
impermeable material installed
over the top of a closed
landfill to prevent infiltration
of rainwater and minimize
leachate. |
|
Capillary Action |
Upward movement of water through
very small spaces due to
molecular forces and surface
tension, called capillary
forces. |
|
Capillary Fringe |
A
zone of porous material lying
between the unsaturated and
saturated zone, just above the
water table, which may hold
water by capillary action in the
smaller void spaces. |
|
Carbon (C) |
An
element, the presence of which
can be used to separate organic
from inorganic compounds. |
|
Carbon Absorber |
An
add-on control device that uses
activated carbon to absorb
volatile organic compounds from
a gas stream. The VOCs are later
recovered from the carbon. |
|
Carbon Adsorption |
A
treatment system that removes
contaminants from groundwater or
surface water by forcing it
through tanks containing
activated carbon treated to
attract the contaminants. |
|
Carbon Dioxide (CO2)
|
A
colorless, odorless,
non-poisonous gas, which results
from fossil fuel combustion and
is normally a part of the
ambient air.
|
|
Carbon Monoxide (CO) |
A
colorless, odorless, poisonous
gas produced by incomplete
fossil fuel combustion. |
|
Carcinogen |
1)
Any substance that can cause,
aggravate, or contribute to the
production of cancer. 2) A
chemical classification for the
purpose of risk assessment based
on the weight of evidence for
human carcinogenicity according
to USEPA 1986 Guidelines for
Risk Assessment, in which
carcinogens are summarized as
follows: Group A: Human
carcinogen: Sufficient evidence
from human epidemiological
studies. Group B:
Probable Human Carcinogen: B1:
Limited evidence from human
epidemiological studies. B2:
Sufficient evidence from animal
studies and inadequate or no
data from human epidemiological
studies. Group C:
Possible Human Carcinogen:
Limited evidence of
carcinogenicity from animal
studies in the absence of human
data. |
|
Carcinogenic |
Causing or producing cancer.
|
Carcinogenic Potency Factor
(CPF) |
The
upper 95th percentile confidence
limit of the slope of the
dose-response curve; expressed
in units of (mg/kg/day)-1.
When derived from human
epidemiological data, the
carcinogenic potency factor may
be a maximum likelihood
estimate. |
|
Carrying Capacity |
1)
In recreation management, the
amount of use a recreation area
can sustain without loss of
quality. 2) In wildlife
management, the maximum number
of animals an area can support
during a given period.
|
|
CAS Registration Number
|
A
number assigned by the Chemical
Abstracts Service to identify a
chemical. |
|
Casing |
Pipe used in water well
construction generally extending
from the land surface to the top
of the well screen. The type and
size of casing used will vary
depending on well yield and
other design requirements.
|
|
Catabolism |
The
process whereby energy is
extracted from organic compounds
by breaking them down into their
component parts. |
|
Catalyst |
An
inorganic substance that changes
the speed, yield, or required
temperature of a chemical
reaction without being consumed
or chemically changed by the
chemical reaction. |
|
Catanadromous |
Fish that swim downstream to
spawn. |
|
Categorical Exclusion (CE)
|
A
class of actions which either
individually or cumulatively
would not have a significant
effect on the human environment
and therefore would not require
preparation of an Environmental
Assessment or Environmental
Impact Statement under the
National Environmental Policy
Act (NEPA). |
|
Cathodic Protection |
A
technique to prevent corrosion
of a metal surface by making it
the cathode of an
electrochemical cell. |
|
Cation Exchange Capacity
|
A
quantitative measure of surface
charge of a cation, reported in
equivalents of exchangeable ions
per unit weight of the solid.
|
|
Cells |
1)
In solid waste disposal, holes
where waste is dumped,
compacted, and covered with
layers of dirt on a daily basis.
2) The smallest structural part
of living matter capable of
functioning as an independent
unit. |
|
Characteristic |
Any
one of the four categories used
in defining hazardous waste:
ignitability, corrosivity,
reactivity, and toxicity. |
|
Characterization |
Facility or site sampling,
monitoring and analysis
activities to determine the
extent and nature of a release.
Characterization provides the
basis for acquiring the
necessary technical information
to develop, screen, analyze, and
select appropriate cleanup
techniques. |
|
Chelate |
A
coordination complex in which
more than one atom or molecule
(often an organic compound)
binds to a metal. In the
environment, chelation
effectively removes the metal:
it is no longer available for
chemical interactions or to
biota. See Complexation. |
|
Chemical Oxygen Demand (COD)
|
A
measure of the oxygen required
to oxidize all compounds, both
organic and inorganic, in water.
|
Chemical
Partitioning |
The
preferential separation of a
chemical into different media or
states. For example, many metals
are more likely to partition to
sediments than to remain in
groundwater. |
Chemical
Resistance |
The
ability of chemical protective
clothing to maintain its
integrity and protection
qualities when it comes into
contact with a hazardous
material. |
|
Chemical Stress |
The
result of a chemical reaction of
two or more materials. Examples
include corrosive materials
attacking a metal, the pressure
or heat generated by the
decomposition or polymerization
of a substance, or any variety
of corrosive actions. |
|
Chemical Treatment |
Any
one of a variety of technologies
that use chemicals or a variety
of chemical processes to treat
waste. |
|
Chemicals of Concern (COC)
|
Specific constituents that are
identified for evaluation in the
risk assessment process. |
|
Chemicals of Potential Concern
(COPC) |
Chemicals identified in the
initial stages of a site
investigation that may pose a
risk, and so are further
investigated to gather data for
a risk assessment. |
|
Chlorides (Cl-)
|
Indicative of the concentration
of salt water. Concentrations
above 250mg/L are detectable by
taste. |
|
Chlorinated Hydrocarbons
|
These include a class of
persistent, broad-spectrum
organic compounds that linger in
the environment and accumulate
in the food chain. Among them
are the insecticides DDT,
aldrin, dieldrin, heptachlor,
chlordane, lindane, endrin,
mirex, hexachloride, and
toxaphene. Other examples
include tetrachloroethene,
trichloroethene, carbon
tetrachloride, and
trichloromethane, used as
industrial solvents. |
|
Chlorinated Solvent |
An
organic hydrocarbon in which
chlorine atoms substitute for
one or more hydrogen atoms in
the compound’s structure, e.g.,
methylene chloride and
1,1,1-trichloromethane. Commonly
used in aerosol spray
containers, in highway paint,
for grease removal in
manufacturing, dry cleaning, and
other operations. The
substituted chlorine makes the
compound less flammable than the
nonsubstituted equivalent, but
more toxic. |
|
Chlorination |
The
application of chlorine to
drinking water, sewage, or
industrial waste to disinfect or
to oxidize undesirable
compounds.
|
|
Chlorine (Cl) |
A
halogen that can substitute for
hydrogen in many organic
compounds. The resulting
compounds are generally less
flammable but highly toxic and
persistent in the environment.
|
|
Chlorofluorocarbons (CFCs)
|
A
family of inert, nontoxic, and
easily liquified chemicals used
in refrigeration, air
conditioning, packaging,
insulation, or as solvents and
aerosol propellants. Because
CFCs are not destroyed in the
lower atmosphere they drift into
the upper atmosphere where their
chlorine components destroy
ozone. |
|
Chromium (Cr) |
A
heavy metal that exists
naturally as the trivalent (III)
form and is man-made in the
hexavalent (VI) form. It is used
in making chrome-steel and
chrome-nickel-steel alloys,
chrome plating of metals, brick
lining for high-temperature
industrial furnaces, dyes,
pigments, leather, wood
preservatives, and cooling tower
water treatment. The ultimate
fate of chromium is to settle
into sediments, however, it is
slightly soluble and can persist
in the water column for years
before settling. In soil,
chromium (III) tends to adhere
to soil particles whereas
chromium (VI) does not. This
process depends on the pH and
redox state of the soil.
Chromium (III) is not very toxic
because it does not
bioaccumulate and generally does
not penetrate biological
membranes. However, chromium
(VI) is considered more toxic
because of its high oxidizing
potential and it can penetrate
biological membranes. Dermal
contact with chromic acid or
chromium salts can cause lesions
and ulcers. Chromium is a Group
B, human carcinogen by
inhalation. See Heavy Metals.
|
|
Chronic Daily Intake (CDI)
|
Exposure expressed as mass of a
substance contacted per unit
body weight per unit time
averaged over a long period of
time (as a Superfund program
guideline, seven years to a
lifetime) mg/kg/day. |
|
Chronic Effect |
An
adverse effect on a human or
animal in which symptoms recur
frequently or develop slowly
over a long period of time.
|
|
Chronic Toxicity |
The
capacity of a substance to cause
long-term poisonous human health
effects. See Acute Toxicity.
|
|
Circle of Influence |
The
circular outer edge of the
depression produced in the water
table by pumping water from a
well. See Cone of Influence,
Cone of Depression. |
|
cis |
In
a chiral (directional) organic
compound, the prefix cis
indicates that the substituted
atoms are on the same side of
the compound. For example, in
cis 1,2-Dichloroethene, the
chlorine atoms are on the same
side of the carbon to carbon
double bond. The presence or
absence of cis or trans
compounds can indicate whether
biological activity or abiotic,
chemical reactions have taken
place in the environment. See
trans. |
|
Clarification |
Clearing action that occurs
during water treatment when
solids settle out. This is often
aided by centrifugal action and
chemically induced coagulation.
|
|
Clarifier |
A
tank in which solids settle to
the bottom and are subsequently
removed as sludge. |
|
Clastic Rock |
A
consolidated sedimentary rock
composed of broken fragments
that are derived from
pre-existing rocks, e.g.
sandstone, conglomerate, shale,
etc. |
|
Clay |
1)
Natural material with plastic
(flowing) properties; 2) A
composition of particles of very
fine size grades; and 3) A
composition of crystalline
fragments of hydrous-aluminum
silicate or hydrous-magnesium
silicate minerals. |
|
Clay Soil |
Soil material containing more
than 40 percent clay, less than
45 percent sand, and less than
40 percent silt. |
|
Clean Air Act (CAA) |
The
CAA was passed in 1970 as
amendments to 42 USC 7401, and
was amended in 1990. Its purpose
is to "protect and enhance the
quality of the Nation's air
resources." Its primary
application is through
Prevention of Significant
Deterioration permits to
regulate new potentially
polluting facilities. Of
increasing importance are the
National Emissions Standards for
Hazardous Air Pollutants
(NESHAPs). |
|
Clean Water Act of 1977 (CWA)
|
The
CWA amended the Federal Water
Pollution Control Act first
passed in 1956. Its objective is
to "restore and maintain the
chemical, physical and
biological integrity of the
Nation's waters." The Act's
major enforcement tool is the
National Pollutant Discharge
Elimination System (NPDES)
permit. |
|
Cleanup |
Actions taken to deal with a
release or threat of release of
a hazardous substance that could
affect humans and/or the
environment. The term "cleanup"
is sometimes used
interchangeably with the terms
remedial action, removal action,
response action, or corrective
action.
|
|
Cleanup Level |
The
residual concentration of a
hazardous substance in a medium
that is determined to be
protective of human health and
the environment under specified
exposure conditions. |
|
Cleanup Technology |
A
technology that is the whole or
part of a treatment train to
cleanup hazardous waste sites.
|
|
Climatology |
The
science that deals with the
climate and climatic phenomena.
|
|
Closeout |
Conducted when DON considers no
further response actions under
the IR Program to be appropriate
for the site and when site
cleanup confirms that no
significant threat to public
health or the environment
exists. The Navy forwards
closeout documentation to the
regulators for concurrence.
|
|
Closure |
The
regulatory process of
deactivating, stabilizing and or
decontaminating waste management
units or facilities under RCRA.
|
|
Closure Plan |
Documentation prepared to guide
the deactivation, stabilization
and surveillance of a waste
management unit or facility
under RCRA. |
|
Coagulation |
Clumping of particles in water
to settle out impurities, often
induced by chemicals such as
lime, alum, and iron salts.
|
|
Coastal Plains |
Any
plain which has its margin on
the shore of a large body of
water, particularly the sea, and
generally represents a strip of
recently emerged sea floor.
|
|
Coastal Zone |
As
defined by the NCP, all US
waters subject to the tide, US
waters of the Great Lakes,
specified ports and harbors on
inland rivers, waters of the
contiguous zone, other waters of
the high seas subject to the
NCP, and the land surface or
land substrata, groundwaters,
and ambient air proximal to
those waters. The term coastal
zone delineates an area of
federal responsibility for
response action. Precise
boundaries are determined by
EPA/USCG agreements and
identified in federal regional
contingency plans.
|
|
Cobalt (Co) |
A
hard, ductile, ferromagnetic
metal. It is rare but produced
primarily as a byproduct of
other metals. It is used in
chemical agents, electroplating,
ceramics, lamp filaments,
catalysts, dryers in printing
inks, paints and varnishes, and
in high temperature alloys.
Cobalt can be soluble in water,
but depends mainly on the
presence and characteristics of
adsorbing clay minerals and
hydrous oxides of iron,
manganese and aluminum in the
local environment. Chelation is
also possible. |
|
Code of Federal Regulation (CFR)
|
The
basic reference source for
federal rules. Published
annually, it is a compilation of
the regulations of various
federal agencies. The CFR is
divided into 50 titles according
to subject. For example, Title 7
deals with agriculture, Title 40
with the environment and Title
49 with transportation. Titles
are divided into chapters, then
to parts, sections, etc. The
section is the basic unit of the
CFR. Ideally, it consists of a
short, concise presentation of a
single point. It is important to
note that the CFRs are changed
daily by publication of the
Federal Register (FR). The CFRs
are the combination of
regulations published in the FR
for the previous year. |
|
Coefficient of Variation (CV)
|
The
standard deviation as a percent
of the arithmetic mean. |
|
Coliform Bacteria |
A
group of bacteria considered a
reliable indicator of the
adequacy of treatment for
bacterial pathogens. |
|
Coliform Index |
A
rating of the purity of water
based on a count of fecal
bacteria. |
|
Coliform Organism |
Microorganisms found in the
intestinal tract of humans and
animals. Their presence in water
indicates fecal pollution and
potentially adverse
contamination by pathogens.
|
|
Colloids |
Very small, less than 1 ðmm,
finely divided solids (that do
not dissolve) that remain
dispersed in a liquid for a long
time due to their small size and
electrical charge. |
|
Combustible |
A
term the NFPA, DOT, and others
use to classify certain
materials with low flash points
that ignite easily. Both NFPA
and DOT generally define
combustible liquids as having a
flash point of 100° F (38° C) or
higher. The NFPA classifies
nonliquid materials such as wood
and paper as ordinary
combustibles. OSHA defines
combustible liquids within the
Hazard Communication Law as any
liquid with a flash point at or
above 100° F (38° C) but below
200° F (93.3° C). |
|
Combustion |
1)
Burning, or rapid oxidation,
accompanied by release of energy
in the form of heat, light,
and/or sound. A basic cause of
air pollution. 2) Refers to
controlled burning of waste, in
which heat chemically alters
organic compounds, converting
into stable compounds such as
carbon dioxide and water. |
|
Combustion Chamber |
The
actual compartment where waste
is burned in an incinerator.
|
|
Cometabolism |
A
reaction in which microbes
transform a contaminant even
though the contaminant cannot
serve as an energy source for
the organisms. To degrade the
contaminant, the microbes
require the presence of other
compounds (primary substrates)
that can support their growth.
|
|
Comment Period |
Time provided for the public to
review and comment on a proposed
action or rule making after
publication in the Federal
Register or as a document. |
|
Commercial Waste |
All
solid waste emanating from
business establishments such as
stores, markets, office
buildings, restaurants, shopping
centers, and theaters. |
|
Commercial Waste Management
Facility |
A
treatment, storage, disposal, or
transfer facility which accepts
waste from a variety of sources,
as compared to a private
facility which normally manages
a limited waste stream generated
by its own operations.
|
|
Community |
In
ecology, a group of interacting
populations in time and space.
Sometimes, a particular
subgrouping may be specified,
such as the fish community in a
lake or the soil arthropod
community in a forest.
|
|
Community Environmental Response
Facilitation Act of 1992 (CERFA)
|
This law amends CERCLA and
requires that the federal
government identify real
property which is not
contaminated, and that offers
the greatest opportunity for
expedited reuse and
redevelopment by the community
on each facility. The identified
parcels of real property must be
either free from hazardous
substances and petroleum
products, including aviation
fuel and motor oil, and their
derivatives, or the remediation
of contamination by those
substances should be expedited
to facilitate transfer to the
public. |
|
Community Relations |
The
effort to establish two-way
communication with the public to
create understanding of
Installation Restoration Program
and related actions, to assure
public input into
decision-making processes
related to affected communities,
and to make certain that the
Navy is aware of and responsive
to public concerns. Specific
community relations activities
are required in relation to
Superfund remedial actions. The
term "public" includes citizens
directly affected by the site,
other interested citizens or
parties, organized groups,
elected officials, and
potentially responsible parties.
|
|
Community Relations Plan (CRP)
|
A
written plan of action that
provides for interaction with
the public, elected officials
and environmental groups,
including obtaining their input
at appropriate points during the
Installation Restoration (IR)
process. A CRP must be developed
and implemented for removal
actions and remedial actions at
all IR sites. It will be based
on research conducted by
community interviews with state
and local officials, citizen and
community groups, interested
residents, and local media
representatives.
|
|
Community Reuse Plan |
The
basis for the proposed action
and alternatives addressed in
the DOD Component's EIS or other
NEPA analyses. |
|
Community Water System |
In
Virginia, as defined by the
Virginia Department of Health, a
water system serving at least 25
individuals or more than 15
residential connections. |
|
Comparability |
A
qualitative measure of the
confidence with which one data
set can be compared to another.
Sample data should be comparable
with other measurement data for
similar samples and sample
conditions. |
|
Completeness |
A
measure of the amount of valid
data obtained from a measurement
system compared to the amount
that was expected to be obtained
under routine operating
conditions. |
|
Complexation |
Electrostatic association of
positively charged metal ions
and negatively charged organic
matter, usually with two or more
points of attachment. See
Chelate. |
|
Composite Sample |
A
representative sample created by
the homogenization of multiple
samples from multiple sampling
locations within the same
general area. A composite sample
is generally taken to indicate
the average concentration in a
particle media. For example,
composite samples are often
taken of soil to characterize it
for disposal. Typically, only
one sample is necessary for
every 100 cubic yards.
Therefore, several grab samples
from each roll-off containing
the soil may be homogenized to
form the composite sample. Taken
in this way, the composite will
represent an average
concentration of the chemicals
of concern for the soil. |
|
Compost |
The
relatively stable humus material
that is produced from a
composting process in which
bacteria in soil mixed with
garbage and degradable trash
break down the mixture into
organic fertilizer. |
|
Composting |
The
controlled biological
decomposition of organic
material in the presence of air
and water to form a humus-like
material. Controlled methods of
composting include mechanical
mixing and aerating, ventilating
the materials by dropping them
through a vertical series of
aerated chambers, or placing the
compost in piles out in the open
air and mixing it or turning it
periodically. |
|
Comprehensive Environmental
Response, Compensation and
Liability Act (CERCLA) |
The
Federal statute enacted in 1980
and amended in 1986 by the
Superfund Amendment and
Reauthorization Act (SARA) that
establishes a comprehensive,
statutory framework for
identifying, investigating, and
cleaning up releases of
hazardous substances to the
environment. CERCLA authorizes
the President to take response
actions when a release or the
threat of a release is
discovered. Through Executive
Order 12580, signed in January
1987, the President directs the
Secretary of Defense to
implement investigation and
cleanup measures in consultation
with EPA for releases of
hazardous substances from
facilities under the
jurisdiction of the Secretary.
|
|
Comprehensive Environmental
Response, Compensation and
Liability Act Information System
(CERCLIS) |
EPA's comprehensive database and
management system that
inventories and tracks releases
addressed or needing to be
addressed by the Superfund
program. CERCLIS contains the
official inventory of CERCLA
sites and supports EPA's site
planning and tracking functions.
Sites that EPA decides do not
warrant moving further in the
site evaluation process are
given a "No Further Response
Action Planned" (NFRAP)
designation. This means that no
additional federal steps under
CERCLA will be taken at the site
unless further information
warrants action. Sites are not
removed from the data base after
completion of evaluations in
order to document that these
evaluations took place and to
preclude the possibility that
they be needlessly repeated.
Inclusion of a specific site or
area in the CERCLIS database
does not represent a
determination of any party's
liability, nor does it represent
a finding that any response
action is necessary. Sites that
are deleted from the NPL are not
designated NFRAP sites. Deleted
sites are listed in a separate
category in the CERCLIS
database. |
|
Comprehensive Long Term
Environmental Action, Navy
(CLEAN) |
A
broad multi-year environmental
contract. |
|
Compressed Natural Gas (CNG)
|
An
alternative fuel for motor
vehicles; considered one of the
cleanest because of low
hydrocarbon emissions and its
vapors are relatively non-ozone
producing. However, it does emit
a significant quantity of
nitrogen oxides. |
|
Conductance |
A
rapid method of estimating the
dissolved-solids content of a
water supply by determining the
capacity of a water sample to
carry an electrical current.
|
|
Conductivity |
A
measure of the ability of a
solution or material to carry an
electrical current. |
|
Cone of Depression |
A
conelike depression of the water
table (or of a potentiometric
surface of a confined aquifer)
that is created in the vicinity
of a well by pumping. The
surface area included in the
cone is known as the area of
influence of the well. |
|
Cone of Influence |
The
depression, roughly conical in
shape, produced in the water
table by the pumping of water
from a well. |
|
Confined Aquifer |
An
aquifer in which groundwater is
confined between two aquitards
and is under pressure which is
significantly greater than
atmospheric pressure. |
|
Confinement |
Confinement techniques are the
actions necessary to confine a
hazardous material release to a
limited area. These actions
occur remote from the spill or
leak site and are therefore
defensive. |
|
Confining Unit |
A
stratigraphic unit which,
because of low permeability
relative to the units above or
below, prevents or impedes
upward or downward movement of
water and pressure. |
|
Conservation |
Preserving and renewing, when
possible, human and natural
resources. The use, protection,
and improvement of natural
resources according to
principles that will assure
their highest economic or social
benefits. |
|
Consolidated |
A
rock that is firm and rigid in
nature due to the natural
interlocking and/or cementation
of its mineral grain components.
The reverse is unconsolidated.
|
|
Construction and Demolition
Waste |
Waste building materials,
dredging materials, tree stumps,
and rubble resulting from
construction, remodeling,
repair, and demolition of homes,
commercial buildings and other
structures and pavements. May
contain lead, asbestos, or other
hazardous substances. |
|
Consumptive Use |
Water removed from available
supplies without return to a
water resource system (uses such
as manufacturing, agriculture,
and food preparation.) |
|
Contaminant |
1)
Any physical, chemical,
biological, or radiological
substance or matter that has an
adverse affect on air, water, or
soil. 2) As defined by section
101(33) of CERCLA, shall include
but not be limited to, any
element, substance, compound or
mixture, including
disease-causing agents, which
after release into the
environment and upon exposure,
ingestion, inhalation, or
assimilation into any organism,
either directly from the
environment or indirectly by
ingestion through food chains,
will or may reasonably be
anticipated to cause death,
disease, behavioral
abnormalities, cancer, genetic
mutation, physiological
malfunctions (including
malfunctions in reproduction) or
physical deformations, in such
organisms or their offspring.
Shall not include petroleum,
including crude oil or any
fraction thereof which is not
otherwise specifically listed or
designated as a hazardous
substance and shall not include
natural gas, liquified natural
gas or synthetic gas of pipeline
quality (or mixtures of natural
gas and such synthetic gas). 3)
For purposes of the NCP, the
term pollutant or contaminant
means any pollutant or
contaminant that may present an
imminent and substantial danger
to public health or welfare.
|
|
Contaminant Hazard Factor (CHF)
|
A
combined measure of contaminant
concentrations in a given
environmental medium. |
|
Contaminated Site |
Any
property, including but not
limited to structures, sediment,
soil and water, that contains a
contaminant resulting from a
discharge or release. |
|
Contamination |
Introduction into water, air
and/or soil of microorganisms,
chemicals, toxic substances,
wastes, or wastewater in a
concentration that makes the
medium unfit for its next
intended use. Also applies to
surfaces of objects and
buildings, and various household
and agricultural use products.
|
|
Contamination Reduction Zone
(CRZ) |
In
hazardous waste health and
safety operations, the forward
control for operations outside
the Hot Zone. Personnel
protection may be required.
Restricted to operations and
support personnel essential to
hands-on work performed in the
Hot Zone. |
|
Contiguous Zone |
A
zone of the high seas,
established by the U. S. under
the Convention on the
Territorial Sea and Contiguous
Zone, that is in contact with or
touching the territorial sea and
that extends 9 nautical miles
seaward from the outer limit of
the territorial sea. |
|
Continuing Calibration |
Analytical standard run every
ten analytical samples or every
two hours, whichever is more
frequent, to verify the
calibration of the analytical
systems. |
|
Contract Required Detection
Limit (CRDL) |
Minimum level of detection
acceptable under the contract
Statement of Work. |
|
Control Limits |
A
range within which specified
measurement results must fall to
be compliant. Control limits may
be mandatory, requiring
corrective action if exceeded,
or advisory, requiring that
noncompliant data be flagged.
|
|
Conventional Pollutants
|
Statutorily listed pollutants
understood well by scientists.
These may be in the form of
organic waste, sediment, acid,
bacteria, viruses, nutrients,
oil and grease, or heat. |
|
Cooperative Agreement (CA)
|
1)
Part of the DSMOA program. The
CA assists in implementing the
DSMOA. The CA provides
reimbursement to states for
cleanup activities at
installations within the state.
2) An assistance agreement
whereby EPA transfers money,
property, services or anything
of value to a state for the
accomplishment of
CERCLA-authorized activities or
tasks. |
|
Copper (Cu) |
A
ductile, malleable metal that
occurs naturally in rock, soil,
water, sediment, plants and
animals and can occur as copper
(II) or (I). It is used in
brass, copper alloys, electrical
conductors, copper salts, art,
in agriculture to treat plant
diseases, for water treatment,
and as preservatives for wood,
leather and fabrics. Most copper
in water is in the (II) state
and is bound to organic matter
and not in a readily
exchangeable form. In soil,
copper will be strongly
adsorbed. Copper salts are
strong skin and mucous membrane
irritants. When bioavailable,
copper is highly toxic to
aquatic invertebrates. |
|
Corrective Action (CA) |
The
sequence of actions that include
site assessment, interim
remedial action, remedial
action, operation and
maintenance of equipment,
monitoring of progress, and
termination of the remedial
action.
|
|
Corrective Action Plan (CAP)
|
Associated with the Underground
Storage Tank (UST) Program, it
describes the appropriate
corrective measures to be
implemented at a site.
Equivalent to a CERCLA
Feasibility Study (FS). |
|
Corrective Measures
Implementation (CMI) |
The
RCRA Corrective Action phase
during which the selected
cleanup technology is
constructed, installed,
implemented and/or operated
until confirmatory sampling and
analysis indicate that cleanup
levels have been reached.
Equivalent to a CERCLA Remedial
Action (RA). |
|
Corrective Measures Study (CMS)
|
Evaluates the alternatives for
cleanup technology in terms of
the specific site
characteristics such as
contaminants, soil conditions
and hydrogeologic conditions in
a RCRA Corrective Action
cleanup. Equivalent to a CERCLA
Feasibility Study (FS). |
|
Correlation Coefficient (r)
|
A
number which indicates the
degree of dependence between two
variables (concentration -
absorbance). The more dependent
they are, the closer the value
of r to one. Determined on the
basis of the least squares line.
|
|
Correspondence |
Any
official letters, memorandums,
notes, telecommunications, and
any other forms of addressed,
written communications sent and
received by the EFD/EFA or other
sources. Internal Department of
Navy drafts and related internal
memorandum should not be
included in the Administrative
Record (AR) unless they contain
information found nowhere else
that is considered or relied
upon in the CERCLA response
action decision. Drafts that are
circulated outside of DON for
review (e.g., to regulators or
the public) shall be included in
the AR as well as the comments
received by DON from those
entities (and DON response to
those comments). |
|
Corrosion |
The
dissolution and wearing away of
metal caused by a chemical
reaction such as between water
and pipes, chemicals touching a
metal surface, or contact
between two metals. |
|
Corrosive |
A
chemical agent that reacts with
the surface of a material
causing it to deteriorate or
wear away. |
|
Corrosivity Hazard |
A
material that causes visible
destruction of or irreversible
alterations to living tissue by
chemical action at the point of
contact. |
|
Cosolvent Effects |
When more than one solvent is
dissolved in aqueous solution,
the solubility of each solvent
can be increased due to the
presence of other solvents.
|
|
Cost/Benefit Analysis |
A
quantitative evaluation of the
costs which would be incurred
versus the overall benefits to
society of a proposed action
such as the establishment of an
acceptable dose of a toxic
chemical. |
|
Cost-Effective Alternative
|
An
alternative control or
corrective method identified
after analysis as being the best
available in terms of
reliability, performance, and
cost. Although costs are one
important consideration,
regulatory and compliance
analysis does not require EPA to
choose the least expensive
alternative. For example, when
selecting or approving a method
for cleaning up a Superfund site
the Agency balances costs with
the long-term effectiveness of
the methods proposed and the
potential danger posed by the
site. |
|
Cost Recovery |
A
legal process by which
potentially responsible parties
who contributed to contamination
at a Superfund site can be
required to reimburse the
Superfund for money spent during
any cleanup actions by the
federal government. |
|
Cost Sharing |
A
publicly financed program
through which society, as a
beneficiary of environmental
protection, shares part of the
cost of pollution control with
those who must actually install
the controls. In Superfund, the
government may pay part of the
cost of a cleanup action with
those responsible for the
pollution paying the major
share. |
|
Cover Material |
Soil used to cover compacted
solid waste in a sanitary
landfill. |
|
Cradle-to-Grave or Manifest
System |
A
procedure in which hazardous
materials are identified and
tracked as they are produced,
treated, transported, and
disposed of by a series of
permanent, linkable, descriptive
documents (e.g., manifests).
|
|
Criteria |
Descriptive factors taken into
account by EPA in setting
standards for various
pollutants. These factors are
used to determine limits on
allowable concentration levels,
and to limit the number of
violations per year. When issued
by EPA, the criteria provide
guidance to the states on how to
establish their standards. |
|
Cross Section |
A
diagram or drawing that shows
features transected by a given
plane, usually a vertical plane
so that the view shows features
through the depth of the earth.
|
|
Cubic Feet per Minute (CFM)
|
A
measure of the volume of a
substance flowing through air
within a fixed period of time.
With regard to indoor air,
refers to the amount of air, in
cubic feet, that is exchanged
with indoor air in a minute's
time, i.e., the air exchange
rate. |
|
Cumulative Exposure |
The
summation of exposures of an
organism to a chemical over a
period of time. |
|
Cycloalkene |
Unsaturated, monocyclic
hydrocarbon with the formula CnH2n-2.
|
|
Back to
Top |
|
|
D
|
|
|
Data Qualifiers
|
Symbols added as a suffix to
analytical results used to flag
data: - Organic Analysis:
|
|
A |
Indicates that a Tentatively
Identified Compound (TIC) is a
suspected aldol-condensation
product. |
|
B |
The
analyte was found in the
associated blank as well as in
the sample. It indicates
possible/probable blank
contamination and warns the data
user to take appropriate action.
This flag must be used for a TIC
as well as for a positively
identified Target Compound List
(TCL) compound.
|
|
C |
Applies to pesticide results
where the identification has
been confirmed by Gas
Chromatography/ Mass
Spectrometry (GC/MS). Single
component pesticides ³ 10 ng/ðml
in the final extract shall be
confirmed by GC/MS. |
|
D |
Identifies all compounds
identified in an analysis at a
secondary dilution factor. If a
sample or extract is reanalyzed
at a higher dilution factor, as
in the E flag below, the DL
suffix is appended to the sample
number on Form I for the diluted
sample, and all concentration
values reported on that Form I
are flagged with the D flag.
|
|
E |
Identifies compounds whose
concentrations exceed the
calibration range of the GC/MS
instrument for that specific
analysis. This flag will not
apply to pesticides/PCBs
analyzed by GC/EC methods. If
one or more compounds have a
response greater than full
scale, the sample or extract
must be diluted and reanalyzed.
If the dilution of the extract
causes any compounds identified
in the first analysis to be
below the calibration range in
the second analysis, then the
results of both analyses shall
be reported. |
|
J |
Positive identification, but
estimated concentration. This
flag is used either when
estimating a concentration for
TIC where a 1:1 response is
assumed, or when the mass
spectral data indicate the
presence of a compound that
meets the identification
criteria but the result is less
than the sample quantitation
limit but greater than zero.
|
|
N |
Presumptive evidence of
presence, TIC. |
|
NJ |
Estimated concentration of a
TIC. |
|
P |
Used for a pesticide/aroclor
target analyte when there is a
greater than 25 percent
difference for detected
concentrations between the two
GC columns. |
|
Q |
No
analytical result. |
|
R |
Quality control indicates that
sample results are rejected and
data are not usable (compound
may or may not be present).
Resampling and reanalysis are
necessary for verification.
|
|
S |
Estimated due to surrogate
outliers. |
|
T |
Compound present in the TCLP
blank. |
|
U |
Indicates compound was analyzed
for but not detected. The sample
quantitation limit must be
corrected for dilution and for
percent moisture. |
|
X |
Other specific flags and
footnotes may be required to
properly define the results. If
used, they must be fully
described and such description
attached. If more than one is
required, Y and Z are used as
needed. If more than five
qualifiers are required for a
sample result, the X flag can
combine several flags. For
instance, the X flag may combine
the A, B, and D flags for some
samples. |
|
Metals Analysis,
flags differing from organic
analysis: |
|
|
B |
Indicates analyte result between
the instrument detection limit
and contract required detection
limit. |
|
E |
The
reported value is estimated
because of the presence of
interference. An explanatory
note must be included with the
results.
|
|
M |
Duplicate injection precision
not met. |
|
N |
Spiked sample recovery not
within control limits.
|
|
S |
The
reported value was determined by
the Method of Standard
Additions. |
|
W |
Postdigestion spike for Furnace
Atomic Absorption analysis is
out of control limits (85-115%),
while sample absorbance is less
than 50% of spike absorbance.
* - Duplicate analysis not
within control limits. + -
Correlation coefficients for
the Method of Standard Addition
is less than 0.995. |
|
Method (Analytical)
Qualifier: |
|
|
A |
Flame Atomic Absorption (AA).
|
|
AS |
Semiautomated
Spectrophotometric. |
|
AV |
Automated Cold Vapor AA. |
|
C |
Manual Spectrophotometric. |
|
CV |
Manual Cold Vapor AA. |
|
F |
Furnace AA. |
|
NC |
Not
calculated as per protocols.
|
|
NR |
The
analyte is not required to be
analyzed.
|
|
P |
ICP. |
|
T |
Titrimetric. |
|
Data Quality Objectives (DQOs)
|
Quantitative and qualitative
statements specified to ensure
that data of appropriate
quantity and quality is
collected during field
activities to support specific
decisions or regulatory actions.
|
|
Data Validation |
A
systematic effort to review data
to identify any outliers or
errors and thereby cause
deletion or flagging of suspect
values to assure the validity of
the data to the user. This
process may be done by manual or
computer methods. |
|
Daughter Product |
A
compound that results directly
from the biodegradation of
another. For example, cis
1,2-Dichloroethene (cis
1,2-DCE) is commonly a daughter
product of Trichloroethene
(TCE).
|
|
Decay Constant |
A
constant which expresses the
probability that an atom or
molecule of a chemical will
decay in a given time interval.
|
|
Dechlorination |
Removal of chlorine from a
substance by chemically
replacing it with hydrogen or
hydroxide ions in order to
detoxify the substance.
|
|
Decision Document (DD) |
Demonstrates that the response
action chosen is consistent
with, and meets the requirements
of, CERCLA and the NCP; and
documents Navy/Marine Corps
decisions regarding response
action selection. Equivalent to
a Record of Decison for non-NPL
sites. |
|
Decomposition |
The
breakdown of matter by bacteria
and fungi, changing the chemical
makeup and physical appearance
of materials. |
|
Decontamination |
Removal of harmful substances
from exposed individuals, rooms
and furnishings in buildings, or
the exterior environment.
|
|
Defense Environmental Network
and Information Exchange (DENIX)
|
A
DOD-wide information exchange to
facilitate and support
communications and environmental
awareness; consists of an
integrated set of menus
comprising a collection of
application programs, databases,
bulletin board forums, and UNIX
utilities to complement other
existing services available;
provides access to a wide
variety of information which can
be downloaded to personal
computers. |
|
Defense Environmental
Restoration Account (DERA)
|
DOD-established account to pay
the cost of DOD expenses to
clean up hazardous waste sites;
DOD transfers DERA funds to the
services for uses consistent
with the DERP; the DOD
counterpart of the Superfund
Program regulated under CERCLA
and SARA and RCRA Corrective
Action. |
|
Defense Environmental
Restoration Program (DERP)
|
Formally established by Congress
in 10 USC 2701-2707 and 2810;
provides centralized management
for the cleanup of DOD hazardous
waste sites consistent with the
provisions of CERCLA as amended
by SARA, the NCP, and E.O.
12580. |
|
Defense Site Environmental
Restoration Tracking System
(DSERTS) |
A
computer based system used to
track environmental restoration
activities at active
installations. The system is
used to collect and maintain
information about environmental
remediation and provide reports
that detail the information at
the DOD Component level. Data
gathered by DSERTS will be
submitted to RMIS for DOD
processing and will be used as
the principal source of
information for each DOD
component in the Annual Report
to Congress.
|
|
Defense/State Memorandum of
Agreement (DSMOA) |
A
grant program to support state
participation in federal
cleanups. |
|
Degradation |
1)
The process by which a chemical
is reduced to a less complex
form. 2) The physical
destruction or decomposition of
a clothing material due to
exposure to chemicals, use, or
ambient conditions (i.e.,
storage in sunlight).
Degradation is noted by visible
signs such as charring,
shrinking, dissolving, or by
testing the clothing material
for weight changes, loss of
fabric tensile strength, etc.
Important in assessing the
continuing protection provided
by protective clothing for
hazardous waste operations.
|
|
Dehydrohalogenation |
Elimination of HX resulting in
formation of an alkene. |
|
Delegated State |
A
state (or other governmental
entity such as a tribal
government) that has received
authority to administer an
environmental regulatory program
in lieu of a federal
counterpart. As used in
connection with NPDES, UIC, and
UST programs, the term does not
connote any transfer of federal
authority to a state. |
|
Delist |
Use
of the petition process to have
a facility's status on the
National Priorities List
rescinded. |
|
Dense Non-Aqueous Phase Liquid
(DNAPL) |
A
liquid that does not dissolve in
water, and so forms a separate
phase from water, which is also
denser than water and therefore
sinks. Many chlorinated solvents
are DNAPLs. |
|
Density |
A
measure of how heavy a solid,
liquid, or gas is for its size.
Mathematically, it is the ratio
of mass to volume of a material,
usually in grams per cubic
centimeter or pounds per gallon.
|
|
Dermal Exposure |
Contact between a chemical and
the skin. |
|
Dermal Toxicity |
The
ability of a pesticide or toxic
chemical to poison people or
animals by contact with the
skin. |
|
Desiccant |
A
chemical agent that absorbs
moisture; some desiccants are
capable of drying out plants or
insects, causing death.
|
|
Design Capacity |
The
average daily flow that a
treatment plant or other
facility is designed to
accommodate. |
|
Designated Uses |
Those water uses identified in
state water quality standards
that must be achieved and
maintained as required under the
Clean Water Act. Uses can
include cold water fisheries,
public water supply, irrigation,
etc. |
|
Designer Bugs |
Popular term for microbes
developed through biotechnology
that can degrade specific toxic
chemicals at their source in
toxic waste dumps or in
groundwater. |
|
Desorption |
The
release of chemicals attached to
solid surfaces. Antonym -
Sorption. |
|
Detection Limit |
The
minimum concentrations which
must be accurately and precisely
measured by the laboratory
and/or specified in the quality
assurance plan. |
|
Detention Time |
1)
The theoretical calculated time
required for a small amount of
water to pass through a tank at
a given rate of flow. 2) The
actual time that a small amount
of water is in a settling basin,
flocculating basin, or rapid-mix
chamber. 3) In storage
reservoirs, the length of time
water will be held before being
used. |
|
Detergent |
Synthetic washing agent that
helps remove dirt and oil. Some
contain compounds which kill
useful bacteria and encourage
algae growth when they are in
wastewater that reaches
receiving waters. |
|
Development Effects |
Adverse effects such as altered
growth, structural abnormality,
functional deficiency, or death
observed in a developing
organism.
|
|
Dewater |
1)
Remove or separate a portion of
the water in a sludge or slurry
to dry the sludge so it can be
handled and disposed. 2) Remove
or drain the water from a tank
or trench. |
|
Diagenesis |
The
chemical and physical changes
occurring in sediments before
consolidation or while in the
environment of deposition.
|
|
Diatoms |
Cellular or colonial
photosynthetic protists most
often in marine environments.
They are very small in size and
are components of plankton, a
major food source at the bottom
of the marine food chain. |
|
Diazinon |
An
insecticide. In 1986, EPA banned
its use on open areas such as
sod farms and golf courses
because it posed a danger to
migratory birds. The ban did not
apply to agricultural, home lawn
or commercial establishment
uses. |
|
Dibenzofurans |
A
group of highly toxic organic
compounds. |
|
Dichloro-Diphenyl-Trichloroethane
(DDT) |
The
first chlorinated hydrocarbon
insecticide. It has a half-life
of 15 years and can accumulate
in fatty tissues of certain
animals. EPA banned registration
and interstate sale of DDT for
virtually all but emergency uses
in the United States in 1972
because of its persistence in
the environment and accumulation
in the food chain. |
|
1,1-Dichloroethene, (1,1-DCE)
|
A
colorless, volatile liquid with
a sweet, mild smell. It is an
intermediate in production of
vinylidene polymer plastics like
SARAN, and is an irritant to the
skin and mucous membranes. It is
a Group C, probable human
carcinogen. |
|
cis 1,2-Dichloroethene, (cis
1,2-DCE) |
A
biological breakdown product of
the more halogenated forms of
ethene, Tetrachloroethene and
Trichloroethene. Also used as an
industrial solvent and is
volatile. |
|
total 1,2-Dichloroethene,
(1,2-DCE) |
Both cis and trans DCE. |
|
trans 1,2-Dichloroethene, (trans
1,2-DCE) |
A
chemical breakdown product of
the more halogenated forms of
ethene, Tetrachloroethene and
Trichloroethene. Also used as an
industrial solvent and is
volatile. |
|
Dicofol |
A
pesticide used on citrus fruits.
|
|
Diffused Air |
A
type of aeration that forces
oxygen into sewage by pumping
air through perforated pipes
inside a holding tank. |
|
Diffusion |
The
movement of a chemical,
suspended, or dissolved particle
from a more concentrated to a
less concentrated area. The
process tends to distribute the
chemical or particles more
uniformly. |
|
Diffusion Coefficient (Kd)
|
Provides a soil or
sediment-specific measure of the
extent of chemical partitioning
between soil or sediment and
water, unadjusted for dependency
upon organic carbon. To adjust
for the fraction of organic
carbon (foc) present
in soil or sediment use Kd
= Koc * foc.
The higher the Kd,
the more likely a chemical is to
bind to soil or sediment than to
remain in water. This affects
the efficiency of water-based
remediation. |
|
Diffusivity |
A
measurement of the movement of a
molecule in a liquid or gas
medium as a result of
differences in concentration. It
is used to calculate the rate of
volatilization of a pure
substance from a surface or in
estimating a Henry's Law
constant for chemicals with low
water solubility. The higher the
diffusivity, the more likely a
chemical is to move in response
to concentration gradients.
|
|
Digestion |
The
biochemical decomposition of
organic matter, resulting in
partial gasification,
liquefaction, and mineralization
of pollutants. |
|
Dike |
A
low wall that can act as a
barrier to prevent a spill from
spreading. |
|
Diluent |
Any
liquid or solid material used to
dilute or carry an active
ingredient. |
|
Dilution Ratio |
The
relationship between the volume
of water in a stream and the
volume of incoming water. It
affects the ability of the
stream to assimilate waste.
|
|
Dinocap |
A
fungicide used primarily by
apple growers to control summer
diseases. EPA proposed
restrictions on its use in 1986
when laboratory tests found it
caused birth defects in rabbits.
|
|
Dinoflagellates |
Flagellated, photosynthetic,
marine protists. They are very
small in size and are components
of plankton, a major food source
at the bottom of the marine food
chain. |
|
Dinoseb |
An
herbicide that is also used as a
fungicide and insecticide. It
was banned by EPA in 1986
because it posed the risk of
birth defects and sterility.
|
|
Dioxin |
A
family of compounds known
chemically as dibenzo-p-dioxins.
Concern about them arises from
their potential toxicity and
contaminants in commercial
products. Tests on laboratory
animals indicate that it is one
of the more toxic man-made
compounds. |
|
Dip Tank |
Generally metal or concrete
units that range in size from 50
to 500 gallons or more. The
tanks are used to clean parts
prior to treatment or to coat
parts with various materials
including metals and plastics.
|
|
Direct Exposure Pathway
|
An
exposure pathway where the point
of exposure is at the source,
without a release to any other
medium. |
|
Direct Filtration |
A
method of treating water which
consists of the addition of
coagulant chemicals, flash
mixing, coagulation, minimal
flocculation, and filtration.
Sedimentation is not used. |
|
Direct Runoff |
Water that flows over the ground
surface or through the ground
directly into streams, rivers,
and lakes. |
|
Direct-Reading Instruments
|
Provide information at the time
of sampling. They are used to
detect and monitor flammable or
explosive atmospheres, oxygen
deficiency, certain gases and
vapors, ionizing radiation, and
free product.
|
|
Discharge |
1)
Flow of surface water in a
stream or canal or the outflow
of groundwater from a flowing
artesian well, ditch, or spring.
2) Discharge of liquid effluent
from a facility or of chemical
emissions into the air through
designated venting mechanisms.
3) As defined by section 311
(a)(2) of the CWA, includes but
is not limited to, any spilling,
leaking, pumping, pouring,
emitting, emptying or dumping of
oil, but excludes discharges in
compliance with a permit under
section 402 of the CWA,
discharges resulting from
circumstances identified and
reviewed and made a part of the
public record with respect to a
permit issued or modified under
section 402 of the CWA, and
subject to a condition in such
permit, or continuous or
anticipated intermittent
discharges from a point source,
identified in a permit or permit
application under section 402 of
the CWA, that are caused by
events occurring within the
scope of relevant operating or
treatment systems. 4) For
purposes of the NCP, discharge
also means threat of discharge.
|
|
Disinfectant |
A
chemical or physical process
that kills pathogenic organisms
in water. Chlorine is often used
to disinfect sewage treatment
effluent, water supplies, wells,
and swimming pools. |
|
Dispersant |
A
chemical agent used to break up
concentrations of organic
material such as spilled oil.
|
|
Dispersion |
Hydrodynamic dispersion; the
process whereby a contaminant
dissolved in groundwater spreads
out in the direction coincident
to and perpendicular to
groundwater flow, causing the
contaminant to become diluted;
the sum of the effects of
mechanical mixing and molecular
diffusion on a dissolved
contaminant that results in
dilution of the contaminant. The
mixing results from differences
in flow path length and velocity
for different molecules. |
|
Dispersivity |
A
property that quantifies
dispersion in a medium.
|
|
Disposables |
Consumer products, other items,
and packaging used once or a few
times and discarded. |
|
Disposal |
Final placement or destruction
of toxic, radioactive, or other
wastes; surplus or banned
pesticides or other chemicals;
polluted soils; and drums
containing hazardous materials
from removal actions or
accidental releases. Disposal
may be accomplished through use
of approved secure landfills,
surface impoundments, land
farming, deep-well injection,
ocean dumping, or incineration.
|
|
Dissolved Metals |
Analyte elements which have not
been digested prior to analysis
and which will pass through a
0.45 ðmm filter. |
|
Dissolved Oxygen (DO) |
The
oxygen freely available in
water, vital to fish and other
aquatic life and for the
prevention of odors. DO levels
are considered a very important
indicator of a water body's
ability to support desirable
aquatic life. Secondary and
advanced waste treatment are
generally designed to ensure
adequate DO in waste-receiving
waters. |
|
Dissolved Solids |
Disintegrated organic and
inorganic material in water.
Excessive amounts make water
unfit to drink or use in
industrial processes. Generally
noticeable in concentrations
greater than 500 mg/L.
|
|
Distillation |
The
act of purifying liquids through
boiling, so that the steam
condenses to a pure liquid and
the pollutants remain in a
concentrated residue. |
|
Diversion |
1)
Use of part of a stream flow as
a water supply. 2) A channel
with a supporting ridge on the
lower side constructed across a
slope to divert water at a
non-erosive velocity to sites
where it can be used or disposed
of. 3) Controlled movement of a
hazardous material to an area
where it will produce less harm.
|
|
Diversion Rate |
The
percentage of waste materials
diverted from traditional
disposal such as landfilling or
incineration to be recycled,
composted, or re-used. |
|
DOD Priority Categories
|
Priorities for DERP funding
determined on the basis of
relative risk (site priorities)
and a hierarchy of site actions
(action priorities) within each
site priority. |
|
Dosage/Dose |
The
actual quantity of a chemical
administered to an organism or
to which it is exposed. |
|
Dose Response |
How
a biological organism's response
to a toxic substance
quantitatively shifts as its
overall exposure to the
substance changes (e.g., a small
dose of carbon monoxide may
cause drowsiness; a large dose
can be fatal.) |
|
Dose-Response Assessment
|
Estimating the potency of a
chemical. |
|
Dose-Response Relationship
|
The
quantitative relationship
between the amount of exposure
to a substance and the extent of
toxic injury or disease
produced.
|
|
DOT Reportable Quantity
|
The
quantity of a substance
specified in US Department of
Transportation regulations that
trigger labeling, packaging and
other requirements related to
shipping such substances. |
|
Downgradient |
The
direction that groundwater
flows; similar to "downstream"
for surface water. |
|
Draft Permit |
A
preliminary permit drafted and
published by EPA; subject to
public review and comment before
final action on the application.
|
|
Drainage Basin |
The
area of land that drains water,
sediment, and dissolved
materials to a common outlet at
some point along a stream
channel.
|
|
Drawdown (s) |
1)
The drop in the water table when
water is being pumped from a
well. It is the vertical
distance between the static and
the pumping levels of the wells.
2) The amount of water used from
a tank or reservoir. 3) The drop
in the water level of a tank or
reservoir. |
|
Dredging |
Removal of mud/sediment from the
bottom of water bodies. This can
disturb the ecosystem and causes
silting that kills aquatic life.
Dredging of contaminated muds
can expose biota to heavy metals
and other toxic compounds.
Dredging activities may be
subject to regulation under
Section 404 of the Clean Water
Act. |
|
Drillers Log |
The
drillers record of material
drilled through in the process
of drilling a well. |
|
Drinking Water Equivalent Level
|
Protective level of exposure
related to potentially
non-carcinogenic effects of
chemicals that are also known to
cause cancer.
|
|
Drinking Water Standard (DWS)
|
Concentration limits for certain
elements and pollutants that may
occur in drinking water;
established by the Safe Drinking
Water Act. |
|
Drinking Water Supply |
As
defined by section 101(7) of
CERCLA, any raw or finished
water source that is or may be
used by a public water system as
defined in the Safe Drinking
Water Act, or as drinking water
by one or more individuals.
|
|
Dry Weight |
The
weight of a sample based on
percent solids. The weight after
drying in an oven. |
|
Dump |
A
site used to dispose of solid
waste without environmental
controls. |
|
Duplicate |
Identical splits of individual
samples which are analyzed by
the laboratory to test for
method reproducibility. Samples
may be split in the laboratory.
|
|
Back to
Top |
|
|
E
|
|
|
Ecological Assessment |
A
qualitative and/or quantitative
appraisal of the actual or
potential effects of chemical(s)
of concern on plants and animals
other than people and domestic
species. |
|
Ecological Impact |
The
effect that a man-made or
natural activity has on living
organisms and their non-living
(abiotic) environment. |
|
Ecological Indicator |
A
characteristic of the
environment that, when measured,
quantifies magnitude of stress,
habitat characteristics, degree
of exposure to a stressor, or
ecological response to exposure.
The term is collective for
response, exposure, habitat, and
stressor indicators. |
|
Ecological Risk Assessment (ERA)
|
The
application of a formal
framework, analytical process,
or model to estimate the effects
of human actions(s) on a natural
resource and to interpret the
significance of those effects in
light of the uncertainties
identified in each component of
the assessment process. Such
analysis includes initial hazard
identification, exposure and
dose response assessments, and
risk characterization. |
|
Ecology |
The
relationship of living things to
one another and their
environment, or the study of
such relationships. |
|
Ecosphere |
The
"bio-bubble" that contains life
on earth, in surface waters, and
in the air. See Biosphere. |
|
Ecosystem |
The
interacting system of a
biological community and its
non-living environmental
surroundings. |
|
Ecosystem Structure |
Attributes related to
instantaneous physical state of
an ecosystem; examples include
species population density,
species richness or evenness,
and standing crop biomass. |
|
Ecotone |
1)
A habitat created by the
juxtaposition of distinctly
different habitats; an edge
habitat. 2) An ecological zone
or boundary where two or more
ecosystems meet. |
|
Effective Porosity for Flow (ne
or nef) |
Represents the interconnected
porosity of a material. In a
porous material, some void
spaces may be saturated but are
not able to transmit water, and
so are not available for flow.
These spaces represent dead
zones of immobile water. nef
corrects the porosity (n) of a
material to account for these
dead spaces. |
|
Effects Range-Low (ER-L)
|
In
aquatic systems, concentrations
of contaminants that below which
adverse biological effects would
rarely occur. Concentrations of
contaminants between the ER-L
and the ER-M represent that
adverse effects would
occasionally occur. |
|
Effects Range-Median (ER-M)
|
In
aquatic systems, concentrations
of contaminants that above which
adverse biological effects would
probably occur. |
|
Effluent |
Wastewater, treated or
untreated, that flows out of a
treatment plant, sewer, or
industrial outfall. Generally
refers to wastes discharged into
surface waters. |
|
Electric Log |
The
log of a well or borehole
obtained by lowering electrodes
in the hole and measuring
various electrical properties of
the geologic formations
traversed. |
|
Electron |
A
negatively charged subatomic
particle that may be transferred
between chemical species in
chemical reactions. Every
chemical molecule contains
electrons and protons
(positively charged particles).
|
|
Electron Acceptor |
Relatively oxidized compounds
which gain electrons from
electron donors during cellular
respiration and
oxidation-reduction reactions,
resulting in the release of
energy to the cell and the
reduction of the electron
acceptor. Microorganisms obtain
energy by transferring electrons
from electron donors such as
organic compounds (or sometimes
reduced inorganic compounds such
as sulfide) to an electron
acceptor. Electron acceptors are
compounds that are relatively
oxidized and include oxygen,
nitrate, iron (III), manganese
(IV), sulfate, carbon dioxide,
or in some cases the chlorinated
aliphatic hydrocarbons such as
tetrachloroethene (PCE),
trichloroethene (TCE),
dichloroethene (DCE) and vinyl
chloride (VC). |
|
Electron Donor |
Organic carbon, or reduced
inorganic compounds, which give
electrons to electron acceptors
during cellular respiration and
oxidation-reduction reactions,
resulting in the release of
energy to the cell, and the
oxidation of the electron donor.
Electron donors are relatively
reduced and include fuel
hydrocarbons, less chlorinated
solvents like vinyl chloride,
and native organic carbon. |
|
Electrophile |
A
reactive species that accepts an
electron pair.
|
|
Elimination |
Chemical reaction where two
groups such as chlorine and
hydrogen are lost from adjacent
carbon atoms and a double bond
is formed in their place. |
|
EMAP Data |
Environmental monitoring data
collected under the auspices of
the Environmental Monitoring and
Assessment Program. All EMAP
data share the common attribute
of being of known quality,
having been collected in the
context of explicit data quality
objectives (DQOs) and a
consistent quality assurance
program. |
|
Emergency (Chemical) |
A
situation created by an
accidental release or spill of
hazardous chemicals that poses a
threat to the safety of workers,
residents, the environment, or
property. |
|
Emerging Technology |
A
technology in the developmental
stage (pilot-scale testing,
bench-scale study) of
production. |
|
Emission |
Pollution discharged into the
atmosphere from smokestacks,
other vents, and surface areas
of commercial or industrial
facilities; from residential
chimneys; and from motor
vehicle, locomotive, or aircraft
exhausts. |
|
Endangered Species |
Animals, birds, fish, plants, or
other living organisms
threatened with extinction by
man-made or natural changes in
their environment. Requirements
for declaring a species
endangered are contained in the
Endangered Species Act. |
|
Endangerment Assessment
|
A
study to determine the nature
and extent of contamination at a
site on the National Priorities
List and the risks posed to
public health or the
environment. EPA or the state
conduct the study when a legal
action is to be taken to direct
potentially responsible parties
to clean up a site or pay for
it. An endangerment assessment
supplements a remedial
investigation. |
|
Endrin |
A
pesticide toxic to freshwater
and marine aquatic life that
produces adverse health effects
in domestic water supplies.
|
|
Energy Recovery |
Obtaining energy from waste
through a variety of processes
(e.g., combustion.) |
|
Enforceable Requirements
|
Conditions or limitations in
permits issued under the Clean
Water Act, Section 402 or 404
that, if violated, could result
in the issuance of a compliance
order or initiation of a civil
or criminal action under federal
or applicable state laws. If a
permit has not been issued, the
term includes any requirement
which, in the Regional
Administrator's judgment, would
be included in the permit when
issued. Where no permit applies,
the term includes any
requirement which the Regional
Administrator determines is
necessary for the best practical
waste treatment technology to
meet applicable criteria. |
|
Enforcement |
EPA, state, or local legal
actions to obtain compliance
with environmental laws, rules,
regulations, or agreements
and/or obtain penalties or
criminal sanctions for
violations. Enforcement
procedures may vary, depending
on the requirements of different
environmental laws and related
implementing regulations. Under
CERCLA, for example, EPA will
seek to require potentially
responsible parties to clean up
a Superfund site, or pay for the
cleanup, whereas under the Clean
Air Act the agency may invoke
sanctions against cities failing
to meet ambient air quality
standards that could prevent
certain types of construction or
federal funding. In other
situations, if investigations by
EPA and state agencies uncover
willful violations, criminal
trials and penalties are sought.
|
|
Enforcement Decision Document
(EDD) |
A
document that provides an
explanation to the public of
EPA's selection of the cleanup
alternative at enforcement sites
on the National Priorities List.
Similar to a Record of Decision.
|
|
Engineering Controls |
Modifications to a site or
facility (for example, slurry
walls, capping, and point of use
water treatment) to reduce or
eliminate the potential for
exposure to a chemical(s) of
concern. |
|
Enrichment |
The
addition of nutrients (e.g.,
nitrogen, phosphorus, carbon
compounds) from sewage effluent
or agricultural runoff to
surface water, greatly increases
the growth potential for algae
and other aquatic plants.
However, too much can be
harmful. |
|
Entrain |
To
trap chemicals and particles in
water either mechanically
through turbulence or chemically
through a reaction. |
|
Environment |
1)
As defined by section 101(8) of
CERCLA, includes the navigable
waters, the waters of the
contiguous zone, and the ocean
waters of which the natural
resources are under the
exclusive management authority
of the U.S., and any other
surface water, groundwater,
drinking water supply, land
surface or subsurface strata,
ambient air, or fish, wildlife
or biota within the U.S. or
under jurisdiction of the U.S.
2) The sum of all external
conditions affecting the life,
development and survival of an
organism. |
|
Environmental Assessment (EA)
|
An
environmental analysis prepared
pursuant to the National
Environmental Policy Act to
determine whether a federal
action would significantly
affect the environment and thus
require a more detailed
environmental impact statement.
|
|
Environmental Audit |
An
independent assessment of the
current status of a party's
compliance with applicable
environmental requirements or of
a party's environmental
compliance policies, practices,
and controls. |
|
Environmental Baseline Survey
for Lease/Transfer (EBSL/EBST)
|
An
evaluation of the environmental
suitability of a parcel for
lease or transfer. |
|
Environmental Contamination
|
The
release of hazardous substances,
or the potential release of a
discarded hazardous substance,
in a quantity which is, or may
become, injurious to the
environment, or the public
health, safety or welfare.
|
|
Environmental Equity |
Equal protection from
environmental hazards of
individuals, groups or
communities regardless of race,
ethnicity, or economic status.
|
|
Environmental Exposure |
Human exposure to pollutants
originating from facility
emissions. Threshold levels are
not necessarily surpassed, but
low level chronic pollutant
exposure is one of the most
common forms of environmental
exposure. See Threshold Level.
|
|
Environmental Impact Statement
(EIS) |
A
document required of federal
agencies by the National
Environmental Policy Act for
major projects or legislative
proposals significantly
affecting the environment. A
tool for decision making, it
describes the positive and
negative effects of the
undertaking and cites
alternative actions. |
|
Environmental Indicator
|
A
measurement, statistic or value
that provides a proximate gauge
or evidence of the effects of
environmental management
programs or of the state or
condition of the environment.
|
|
Environmental Justice |
The
fair treatment of all races,
cultures, incomes, and
educational levels with respect
to the development,
implementation, and enforcement
of environmental laws,
regulations, and policies. Fair
treatment implies that no
population of people should be
forced to shoulder a
disproportionate share of the
negative environmental impacts
of pollution or environmental
hazards due to a lack of
political or economic strength.
|
|
Environmental
Protection Agency (EPA)
|
Established in 1970 by
Presidential Executive Order,
bringing together parts of
various government agencies
involved with control of
pollution. |
|
Environmental Restoration (ER)
|
Cleanup and restoration of sites
contaminated with hazardous
substances during past
production or disposal
activities. |
|
Environmental Restoration, Navy
(ER,N) |
The
Navy established support funds
for oversight of the IR Program.
These support funds are intended
to assist Installations in
meeting oversight requirements.
Replaced DERA Funding |
|
Environmental Risk |
The
potential or likelihood of
injury, disease, or death
resulting from human exposure to
a potential environmental
threat.
|
|
Enzyme |
Biologically produced,
protein-based catalyst.
|
|
Ephemeral |
Lasting a short time,
transitory. |
|
Epidemiology |
Study of the distribution of
disease, or other health-related
states and events in human
populations, as related to age,
sex, occupation, ethnic, and
economic status in order to
identify and alleviate health
problems and promote better
health. |
|
Epoxidation |
A
reaction wherein an oxygen
molecule is inserted in a
carbon-carbon double bond and an
epoxide is formed. |
|
Equilibrium |
A
condition that exists in a
system when the phases of the
system do not undergo any change
of properties with the passage
of time; the state in which the
action of multiple forces
produces a steady balance,
resulting in no change overall,
over time. |
|
Equilibrium Species |
1)
Species whose population exists
in equilibrium with resources
and at a stable density. 2) A
species that has a life history
characterized by long life, long
development time to reach
maturity, low death rates, and
few reproductive cycles per
year. |
|
Equipment Rinsate |
The
final analyte-free water rinse
from equipment cleaning
collected daily during a
sampling event. |
|
Equipotential |
Equal potential (energy). |
|
Equipotential Lines |
Lines of equal potential
(energy). Water flows from areas
of higher potential towards
areas of lower potential. |
|
Equivalent Method |
Any
method of sampling and analyzing
for chemicals which has been
demonstrated to the EPA
Administrator's satisfaction to
be, under specific conditions,
an acceptable alternative to
normally used reference methods.
|
|
Erosion |
The
wearing away of land surface by
wind or water, intensified by
land-clearing practices related
to farming, residential or
industrial development, road
building, or logging. |
|
Estuary |
1)
A semi-enclosed coastal body of
water that has a free connection
with the open sea and within
which seawater is measurably
diluted with fresh water from
land drainage. 2) Regions of
interaction between rivers and
near-shore ocean waters, where
tidal action and river flow mix
fresh and salt water. Such areas
include bays, mouths of rivers,
salt marshes, and lagoons. These
brackish water ecosystems
shelter and feed marine life,
birds, and wildlife. See
Wetlands. |
|
Ethanol |
An
alcohol used as an alternative
automotive fuel derived from
grain and corn; usually blended
with gasoline to form gasohol.
|
|
Ethylene Dibromide (EDB)
|
A
chemical used as an agricultural
fumigant and in certain
industrial processes. Extremely
toxic and found to be a
carcinogen in laboratory
animals, EDB has been banned for
most agricultural uses in the
United States. |
|
Evacuation |
A
prolonged precautionary stay
away from an area affected by a
hazardous material. |
|
Evapotransporation |
The
process by which surface water,
soils, and plants release water
vapor to the atmosphere through
evaporation and transpiration.
|
|
Ex Situ |
Refers to a technology or
process for which contaminated
material must be removed from
the site of contamination for
treatment. For example, soil
must be excavated or groundwater
must be pumped to an above
ground treatment system. Antonym
- In Situ. |
|
Exceedence |
Violation of the pollutant
levels permitted by
environmental protection
standards. |
|
Exchange Capacity |
A
quantitative measure of the
surface charge of a substance,
reported in equivalents of
exchangeable ions per unit
weight of the solid. |
|
Exclusion Zone (EZ) |
The
area surrounding an operation
which may be immediately
dangerous to life and health.
Requires complete, appropriate
protective clothing and
equipment. Entry requires
approval by the Site
Superintendent or a designated
sector officer. Complete back-up
and rescue teams must be in
place at the perimeter before
operations begin. |
|
Exempt Solvent |
Specific organic compounds not
subject to requirements of
regulation because they are
deemed by EPA to be of
negligible photochemical
reactivity. |
|
Exempted Aquifer |
Underground bodies of water
defined in the Underground
Injection Control program as
aquifers that are potential
sources of drinking water though
not being used as such, and thus
exempted from regulations
barring underground injection
activities. |
|
Exemption |
A
state with primacy may relieve a
public water system from a
requirement respecting an MCL,
treatment technique, or both by
granting an exemption if the
system cannot comply due to
compelling economic or other
factors, the system was in
operation on the effective date
of the requirement or MCL, and
the exemption will not create an
unreasonable public health risk.
See Variance. |
|
Exogenous |
1)
Derived or developed from
external causes or locations. 2)
For bioremediation,
microorganisms from other
locations, whose effectiveness
has been tested and added to a
site for remediation. |
|
Exotic Species |
A
species that is not indigenous
to a region.
|
|
Expanding Plume |
The
situation where a groundwater
plume is continuing to move
outward or downgradient from the
source area. |
|
Explosive Limits |
The
amounts of vapor in the air that
form explosive mixtures; limits
are expressed as lower and upper
limits and give the range of
vapor concentrations in air that
will explode if an ignition
source is present. The limits
differ depending on the chemical
vapor present. |
|
Exposure |
Contact of an organism with a
chemical or physical agent.
Exposure is quantified as the
amount of the agent available at
the exchange boundaries of the
organism (e.g., skin, lungs or
gut) and available for
absorption. |
|
Exposure Assessment |
The
determination or estimation
(qualitative or quantitative) of
the method, magnitude,
frequency, duration, and route
of exposure. |
|
Exposure Event |
An
incident of contact with a
chemical or physical agent. An
exposure event can be defined by
time (e.g., day, hour) or by the
incident (e.g., eating a single
meal of contaminated fish).
|
|
Exposure Incident |
A
specific eye, mouth, other
mucous membrane, non-intact
skin, or parental contact with
blood or other potentially
infectious materials. |
|
Exposure Indicator |
A
characteristic of the
environment measured to provide
evidence of the occurrence or
magnitude of a response
indicator's exposure to a
chemical or biological stress.
|
|
Exposure Level (EL) |
The
amount (concentration) of a
chemical at the absorptive
surfaces of an organism. |
|
Exposure Pathway |
The
course a chemical or physical
agent takes from a source to an
exposed organism. An exposure
pathway describes a unique
mechanism by which an individual
or population is exposed to
chemicals or physical agents at,
or originating from, a site.
Each exposure pathway includes a
source or release from a source,
an exposure point, and an
exposure route. If the exposure
point differs from the source, a
transport/exposure medium (e.g.,
air) or media (in cases of
intermedia transfer) also is
included. |
|
Exposure Point |
A
location of potential contact
between an organism and a
chemical or physical agent.
|
|
Exposure Route |
The
manner in which a chemical or
physical agent comes in contact
with an organism (i.e., by
ingestion, inhalation, or dermal
contact). |
|
Extractable |
A
compound that can be partitioned
into an organic solvent from the
sample matrix and is amenable to
gas chromatography. Extractables
include semivolatile (BNA) and
pesticide/PCB compounds. |
|
Extraction Procedure (EP Toxic)
|
Determining toxicity by a
procedure which simulates
leaching; if a certain
concentration of a toxic
substance can be leached from a
waste, that waste is considered
hazardous, i.e., "EP Toxic."
Replaced by the TCLP. |
|
Extremely Hazardous Substances
|
Any
of 406 chemicals identified by
EPA as toxic, and listed under
SARA Title III. The list is
subject to periodic revision.
|
|
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|
|
F
|
|
|
Facility |
As
defined by CERCLA, any building,
structure, installation, pipe or
pipeline, well, pit, pond,
lagoon, impoundment, ditch,
landfill, storage container,
motor vehicle, rolling stock, or
aircraft; or any site or area
where hazardous substances have
been deposited, stored, disposed
of, placed, or otherwise come to
be located. |
|
Facultative |
A
microbial trait enabling aerobic
or anaerobic respiration,
depending on environment. |
|
Facultative Anaerobes |
Microorganisms that use and
prefer oxygen when it is
available, but can also use
alternate electron acceptors
such as nitrate under anaerobic
conditions when necessary. |
|
Falling Head Test |
A
type of Slug Test where a solid
or known volume of water is
quickly added to an aquifer so
that the falling head (water
level in the well) can be
monitored to determine the
hydraulic conductivity. |
|
Fast Track Cleanup |
An
approach to the cleanup of
contamination at closing bases
or sites where the transfer of
property is required quickly.
Parcels with contamination below
cleanup levels will be
identified quickly and made
available for transfer. |
|
Feasibility Study (FS)
|
Based on data collected during
the remedial investigations,
options for final cleanup
actions or remediation are
developed and evaluated. The
most feasible option that
satisfies the applicable or
relevant and appropriate
requirements for mitigating
confirmed environmental
contamination is then
recommended. The FS is divided
into two phases - initial
screening of alternatives, and
detailed analysis of
alternatives. The detailed
analysis considers the following
nine criteria required by the
NCP: 1) Overall Protection of
Human Health and the
Environment, 2) Compliance with
ARARs, 3) Long-Term
Effectiveness and Permanence; 4)
Reduction of Toxicity, Mobility,
and Volume Through Treatment, 5)
Short-Term Effectivenss, 6)
Implementability, 7) Cost, 8)
Community Acceptance, and 9)
State Acceptance. |
|
Fecal Coliform Bacteria
|
Bacteria found in the intestinal
tracts of mammals. Their
presence in water or sludge is
an indicator of pollution and
possible contamination by
pathogens. |
|
Federal Agency Hazardous Waste
Compliance Docket |
Established by Congress under
SARA to identify Federal
facilities that must be
evaluated for potential
inclusion on the NPL and compile
and maintain information on the
cleanup status of these sites.
|
|
Federal Facilities
Agreement (FFA) |
Intended to establish roles and
responsibilities and to improve
communication between all
parties by allowing EPA and the
state to review all work in
support of remedy selection; at
an NPL site, the FFA outlines
the working relationship between
states, EPA, and the Navy. The
FFA is a legal agreement
governing the CERCLA and RCRA
administrative process for
cleanup. An FFA will become an
Interagency Agreement (IAG) when
the statutory requirements are
incorporated after the Record of
Decision (ROD). |
|
Federal Register (FR) |
A
daily publication that acts as
the official notice board for
Presidential and federal agency
documents. It contains documents
of general applicability and
legal effect (e.g. meeting
notices and agency requests for
information); documents required
to be published by statute or
regulation (proposed rules,
final rules); and certain
Presidential documents (e.g.
proclamations and executive
orders). Documents published in
the FR as codified regulations
keep the CFR current. These
documents make changes to the
corresponding CFR volumes. |
|
Fermentation |
Microbial metabolism in which a
particular compound is used both
as an electron donor and an
electron acceptor resulting in
the production of oxidized and
reduced daughter products. |
|
Field Blank |
Blanks are collected and
analyzed to determine the level
of contamination introduced into
the sample due to sampling
technique. They may consist of
the source water used in
decontamination and steam
cleaning. At minimum, one sample
from each event and each source
of water must be collected and
analyzed. |
|
Field Duplicate/Split |
1)
Samples that have been divided
into two or more portions while
in the field. Each portion is
then carried through the
remaining steps in the
measurement process. A sample
may be duplicated in the field
or at different points in the
analytical process. For field
duplicated samples, precision
information would be gained on
homogeneity, handling, shipping,
storage, preparation, and
analysis. 2) Duplicate samples
divided into two parts and sent
to different laboratories and
subjected to the same
environmental conditions and
steps in the measurement process
to test the labs. |
|
Filling |
Depositing dirt, mud, or other
materials into aquatic areas to
create more dry land, usually
for agricultural or commercial
development purposes, often with
ruinous ecological consequences.
|
|
Filter Strip |
Strip or area of vegetation used
for removing sediment, organic
matter, and other pollutants
from runoff and waste water.
|
|
Filtration |
A
treatment process, under the
control of qualified operators,
for removing solid (particulate)
matter from water by means of
porous media such as sand or a
man-made filter; often used to
remove particles containing
pathogens. |
|
Final Action |
Those removal actions that
achieve the final cleanup
objectives, considering
long-term effectiveness and
permanence, for the particular
site, media, or operable unit.
Except for O & M and possibly a
five-year review, final actions
require no additional study or
action after the final actions
are complete. |
|
Financial Assurance for Closure
|
Documentation or proof that an
owner or operator of a facility
such as a landfill or other
waste repository is capable of
paying the projected costs of
closing the facility and
monitoring it afterwards as
provided in RCRA regulations.
|
|
Finding of No Significant Impact
(FNSI) |
A
document prepared by a federal
agency showing why a proposed
action would not have a
significant impact on the
environment and thus would not
require preparation of an
Environmental Impact Statement.
A FNSI is based on the results
of an environmental assessment.
|
|
Finding of Suitability for
Lease/Transfer (FOSL/FOST)
|
Documents that the EBSL/EBST has
determined that the subject
property is suitable for lease
or transfer by deed for the
intended purposes. |
|
First Draw |
The
water that comes out when a tap
is first opened, likely to have
the highest level of lead
contamination from plumbing
materials.
|
|
First Order Reaction |
A
chemical reaction in which an
increase (or decrease) in
reactant concentration results
in a proportional increase (or
decrease) in the rate of the
reaction. |
|
Fix, sample |
A
sample is "fixed" in the field
by adding chemicals that prevent
water quality indicators of
interest in the sample from
changing before laboratory
measurements are made. |
|
Flammable |
Describes any solid, liquid,
vapor, or gas that ignites
easily and burns rapidly. |
|
Flammable Liquid |
A
liquid that gives off vapors
readily ignitable at room
temperature. Defined by the NFPA
and DOT as a liquid with a flash
point below 100° F (38° C).
|
|
Flash Point (FLP) |
The
minimum temperature at which a
liquid gives off enough vapors
that will ignite and flash-over
but will not continue to burn
without the addition of more
heat. |
|
Flocculation |
Process by which clumps of
solids in water or sewage
aggregate through biological or
chemical action so they can be
separated from water or sewage.
|
|
Floodplain |
The
flat or nearly flat land along a
river or stream or in a tidal
area that is covered by water
during a flood. |
|
Flow Rate |
The
rate at which a fluid escapes
from a unit area. Such
measurements are made of liquid
waste, effluent, and surface
water movement. |
|
Flowing Well |
A
well having sufficient artesian
pressure head to discharge water
above the land surface. |
|
Flowmeter |
A
gauge indicating the velocity of
wastewater moving through a
treatment plant, or of any
liquid moving through various
industrial processes. |
|
Fluoride |
A
general reference to compounds
containing fluorine. Presence of
about 1.0 mg/L is beneficial for
reduction of dental cavities.
Concentrations greater than 1.8
mg/L may cause mottling of
teeth. |
|
Fluorine (F) |
The
lightest of the halogens that
can substitute for hydrogen in
many organic compounds. The
resulting compounds are
generally less flammable but
more toxic and persistent in the
environment. |
|
Fluorocarbons (FCs) |
Any
of a number of organic compounds
analogous to hydrocarbons in
which one or more hydrogen atoms
are replaced by fluorine. Once
used in the United States as a
propellant for domestic
aerosols, they are now found
mainly in coolants and some
industrial processes. FCs
containing chlorine are called
chlorofluorocarbons (CFCs). They
are believed to be modifying the
ozone layer in the stratosphere,
thereby allowing more harmful
solar radiation to reach the
Earth's surface. |
|
Flush |
1)
To open a cold-water tap to
clear out all the water which
may have been sitting for a long
time in the pipes. In new homes,
to flush a system means to send
large volumes of water gushing
through the unused pipes to
remove loose particles of solder
and flux. 2) To force large
amounts of water or other liquid
to clean out piping or tubing,
storage or process tanks.
|
|
Fluvial/Deltaic |
Pertaining to rivers, streams,
ponds, or river deltas. |
|
Flux |
A
flowing or flow. For example,
the flow of water through a
pumping well can be called the
flux. |
|
Fly Ash |
Non-combustible residual
particles expelled by flue gas.
|
|
Food Chain |
A
sequence of organisms, each of
which uses the next, lower
member of the sequence as a food
source. |
|
Formaldehyde (CH20)
|
A
colorless, pungent, and
irritating gas, used chiefly as
a disinfectant, preservative,
and in synthesizing other
compounds like resins. |
|
Formation |
A
unit of geologic mapping
consisting of an identifiable
rock material that also has
lateral or vertical continuity.
|
|
Formerly Used Defense Sites
(FUDS) |
The
FUDS process parallels the IR
Program process phases, but the
program structure is different.
FUDS has two major components:
inventory and remediation. In
the inventory phase, projects
are investigated to determine if
the site is eligible. The
remediation phase includes all
of the components of the IR
Program. The FUDS Program is
implemented by the Army Corps of
Engineers. |
|
Fossil Fuel |
Fuel derived from ancient
organic remains, e.g., peat,
coal, crude oil, and natural
gas. |
|
Fracture |
Generally any break in a rock,
whether or not it causes
displacement, due to mechanical
failure by stress; includes
cracks, joints and faults. |
|
Free Product |
Organic contaminant existing as
a separate liquid phase. |
|
Freeboard |
1)
Vertical distance from the
normal water surface to the top
of the confining wall. 2) The
vertical distance from the sand
surface to the underside of a
trough in a sand filter. |
|
Fresh Water |
Water that generally contains
less than 1,000 mg/L of
dissolved solids. |
|
Friable |
Capable of being crumbled,
pulverized, or reduced to powder
by hand pressure. |
|
Fuel Efficiency |
The
proportion of the energy
released on combustion of a fuel
that is converted into useful
energy. |
|
Fully Penetrating Well |
A
well in which the screened
length is equal to the saturated
thickness of the aquifer. |
|
Fungi |
(Singular: Fungus) Molds,
mildews, yeasts, mushrooms, and
puffballs, a group of organisms
lacking in chlorophyll (i.e.,
are not photosynthetic) and
which are usually non-mobile,
filamentous, and multicellular.
Some grow in soil, others attach
themselves to decaying trees and
other plants whence they obtain
nutrients. Some are pathogens,
others stabilize sewage and
digest composted waste. |
|
Future Liability |
Refers to potentially
responsible parties' obligations
to pay for additional response
activities beyond those
specified in the Record of
Decision or Consent Decree.
|
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|
|
G
|
|
|
Game Fish |
Species like trout, salmon, or
bass, caught for sport. Many of
them show more sensitivity to
environmental change than
"rough" fish. |
|
Gamma Ray Log |
A
method of logging wells or
boreholes by observing the
natural radioactivity of rocks
through which the hole passes.
|
|
Gas Chromatograph/Mass
Spectrometer (GC/MS) |
Highly sophisticated instrument
that identifies the molecular
composition and concentrations
of various chemicals in water
and soil samples. |
|
Generator |
1)
A facility or mobile source that
emits pollutants into the air or
releases hazardous waste into
water or soil. 2) Any person
whose act or process produces
regulated medical waste or whose
act first causes such waste to
become subject to regulation. In
a case where more than one
person (e.g., doctors with
separate medical practices) is
located in the same building,
each business entity is a
separate generator. |
|
Geographic Information System
(GIS) |
A
computer system designed for
storing, manipulating,
analyzing, and displaying data
in a geographic context. |
|
Geological Log |
A
detailed description of all
underground features (depth,
thickness, type of formations)
discovered during the drilling
of a well.
|
|
Geophysical Log |
Methods of logging by lowering a
sensing device into a well to
make a record which can be
interpreted in terms of the
rock's characteristics, the
contained fluids, and of the
construction of the well.
|
|
Geoprobe |
A
vehicle-mounted,
hydraulically-powered, soil
probing device that utilizes
static force and percussion to
advance small diameter sampling
tools into the subsurface for
collecting soil core, soil gas,
or groundwater samples. A
registered trademark of Kejr
Engineering, Inc., Salina,
Kansas. |
|
Grab Sample |
A
single sample collected at a
particular time and place that
represents the composition of
the media only at that time and
place.
|
|
Graded |
An
engineering term pertaining to
the variation of sizes in soil
or an unconsolidated sediment; a
soil consisting of particles of
several or many sizes or having
a uniform or equable
distribution of particles from
coarse to fine. Well graded
materials have many sizes,
whereas poorly graded materials
are more uniform in size. |
|
Gradient (i, dH/dX) |
In
an aquifer, the rate of change
in head per unit distance of
flow at a given point and in a
given direction. |
|
Granular Activated Carbon
Treatment (GAC) |
A
filtering system often used in
small water systems and
individual homes to remove
organics. GAC can be highly
effective in removing elevated
levels of radon from water.
|
|
Gravel Pack |
Gravel placed around the outside
of the well screen to increase
the effective diameter of the
well and therefore the well
efficiency. |
|
Ground Cover |
Plants grown to keep soil from
eroding. |
|
Groundwater (GW) |
The
supply of fresh water found
beneath the Earth's surface in
the interstices between soil
grains, in fractures, or in
porous formations. Because
groundwater is a major source of
drinking water, there is growing
concern over contamination from
leaching agricultural or
industrial pollutants or leaking
underground storage tanks. |
|
Groundwater Discharge |
Groundwater entering near
coastal waters which has been
contaminated by landfill
leachate, deep well injection of
hazardous wastes, septic tanks,
etc. |
|
Groundwater Flow |
The
movement of water through
openings in sediment and rock
that occurs in the zone of
saturation. |
|
Groundwater Flow Velocity
|
A
measure of the direction and
speed of Groundwater Flow. |
|
Groundwater Remediation
|
Treatment of groundwater to
remove pollutants.
|
|
Gully Erosion |
Severe erosion in which trenches
are cut to a depth greater than
30 centimeters (a foot).
Generally, ditches deep enough
to cross with farm equipment are
considered gullies. |
|
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|
|
H |
|
|
Habitat |
The
place where a population (e.g.,
human, animal, plant,
microorganism) lives, and its
surroundings, both living and
non-living.
|
|
Habitat Indicator |
A
physical attribute of the
environment measured to
characterize conditions
necessary to support an
organism, population, or
community in the absence of
pollutants, e.g., salinity of
estuarine waters or substrate
type in streams or lakes. |
|
Half-Life |
(physical, biological or
effective) -1) The time for a
quantity of material/chemical to
diminish by a factor of half
(because of nuclear decay
events, biological elimination
of the material, or both). The
greater the half-life, the more
persistent a material/chemical
is likely to be. For example,
the biochemical half-life of DDT
in the environment is 15 years,
Radium is 1,580 years. 2) The
time required for half of the
atoms of a radioactive element
to undergo self-transmutation or
decay. 3) The time required for
the elimination of one half a
total dose from the body. |
|
Halogen |
Any
of a group of five
chemically-related, nonmetallic
elements that includes bromine,
fluorine, chlorine, iodine, and
astatine. Can combine with
metals to form salts or
substitute for hydrogen in many
organic compounds. The resultant
halogenated compound is
generally less flammable but
more toxic. |
|
Halogenated |
Organic compounds containing one
or more halogens substituted for
hydrogen. The resulting
substituted compound is
generally less flammable but
more toxic. |
|
Halon |
Bromine-containing compounds
with long atmospheric lifetimes
whose breakdown in the
stratosphere causes depletion of
ozone. Halons are used in
fire-fighting. |
|
Hand Auger Drilling |
Hand drilling by rotating a
spiral channel supported on a
shaft. |
|
Hardness |
Characteristic of alkaline water
caused by the presence of
various salts. Hard water may
interfere with some industrial
processes and prevent soap from
lathering. |
|
Hauler |
Waste collection company that
offers refuse or waste removal
service; many will also collect
recyclables. |
|
Hazard Communication Standard
|
An
OSHA regulation that requires
chemical manufacturers,
suppliers, and importers to
assess the hazards of the
chemicals that they make,
supply, or import, and to inform
employers, customers, and
workers of these hazards through
Material Safety Data Sheets.
|
|
Hazard Evaluation |
A
component of risk evaluation
that involves gathering and
evaluating data on the types of
health injury or disease that
may be produced by a chemical
and on the conditions of
exposure under which such health
effects are produced. |
|
Hazard Identification |
Determining if a chemical can
cause adverse health effects in
humans and what those effects
might be. |
|
Hazard Index (HI) |
The
sum of more than one Hazard
Quotient for multiple substances
and/or multiple exposure
pathways. The HI is calculated
separately for chronic,
subchronic and shorter-duration
exposures. The HI indicates the
risk from the presence of
multiple substances at one site,
or exposures to the same
chemicals through multiple media
and pathways. |
|
Hazard Index, Total (HIT)
|
Sum
of media specific Hazard
Quotients for non-carcinogens.
|
|
Hazard Quotient (HQ) |
The
ratio of a single substance
exposure level over a specified
time period to a reference dose
for that substance derived from
a similar exposure period.
Indicates the hazard or risk
from exposure to that substance.
|
|
Hazardous Air Pollutants (HAP)
|
Air
pollutants which are not covered
by ambient air quality standards
but which, as defined in the
Clean Air Act, may reasonably be
expected to cause or contribute
to irreversible illness or
death. Such pollutants include
asbestos, beryllium, mercury,
benzene, coke oven emissions,
radionuclides, and vinyl
chloride. |
|
Hazardous Chemical |
An
EPA designation for any
hazardous material requiring an
MSDS under OSHA's Hazard
Communication Standard. Such
substances are capable of
producing fires and explosions
or adverse health effects like
cancer and dermatitis. Hazardous
chemicals are distinct from
hazardous waste. See Hazardous
Waste. |
|
Hazardous Material (HM)
|
Any
material which, because of its
quantity, concentration, or
physical, chemical, or
infectious characteristics may
pose a substantial hazard to
human health or the environment
when released or spilled.
|
|
Hazardous Ranking
System (HRS) |
The
principle screening tool used by
EPA to evaluate risks to public
health and the environment
associated with abandoned or
uncontrolled hazardous waste
sites. The HRS calculates a
score based on the potential of
hazardous substances spreading
from the site through the air,
surface water, or groundwater,
and on other factors such as
density and proximity of human
population. This score is the
primary factor in deciding if
the site should be on the
National Priorities List and, if
so, what ranking it should have
compared to other sites on the
list. |
|
Hazardous Ranking System,
Revised (HRS 2) |
The
method used by EPA to evaluate
the relative potential of
hazardous substance releases to
cause health or safety problems,
or ecological or environmental
damage. It is the primary
mechanism used by EPA to place
sites on the NPL. The EPA bases
the score on evaluation of three
contaminant migration pathways.
A score of 28.50 or above will
require the site to be placed on
the NPL. The score is based on
such factors as amount and
toxicity of contaminants,
potential mobility, pathways for
human exposure and proximity of
population centers. EPA issued
the HRS in 1990, and it became
effective in March 1991. The
revised HRS (HRS 2) incorporates
SARA requirements and
improvements identified by EPA
and the public including an
assessment of ecological
effects. |
|
Hazardous Substance (HS)
|
1)
Any material that poses a threat
to human health and/or the
environment. Typical hazardous
substances are toxic, corrosive,
ignitable, explosive, or
chemically reactive. 2) Any
substance designated by EPA to
be reported if a designated
quantity of the substance is
spilled in the waters of the
United States or if otherwise
released into the environment.
|
|
Hazardous Waste (HW) |
1)
A solid waste or combination of
solid wastes which because of
its quantity, concentration, or
physical, chemical, or
infectious characteristics may:
A) Cause or contribute to an
increase in mortality or to a
serious, irreversible, or
incapacitating reversible
illness; or B) Pose a
substantial present or potential
hazard to human health or the
environment when improperly
treated, stored, transported,
disposed of or otherwise
managed. Hazardous wastes may be
listed (named on a list
within a regulation) or
characteristic (exhibits one
of the four characteristics:
corrosive, toxic, ignitable or
reactive). 2) By-products of
society that can pose a
substantial or potential hazard
to human health or the
environment when improperly
managed. |
|
Hazardous Waste Landfill
|
An
excavated or engineered site
where hazardous waste is
deposited and covered. |
|
Hazards Analysis |
Procedures used to 1) identify
potential sources of released
hazardous materials from fixed
facilities or transportation
accidents; 2) determine the
vulnerability of a geographical
area to a release of hazardous
materials; and 3) compare
hazards to determine which
present greater or lesser risks
to a community. |
|
Hazards Identification |
Providing information on which
facilities have extremely
hazardous substances, what those
chemicals are, how much there is
at each facility, how the
chemicals are stored, and
whether they are used at high
temperatures. |
|
Head |
1)
The elevation of the groundwater
table above a specified point.
2) The height above a standard
reference (datum) of the surface
of a column of water or other
liquid. Head is the sum of three
components at a point: a)
Elevation head, which is equal
to the elevation of the point
above a datum, b) Pressure head,
which is the height of a column
of static water that can be
supported by static pressure at
the point, and c) Velocity head,
which is the height the kinetic
energy of the liquid is capable
of lifting the liquid.
|
|
Health Advisory Level |
A
non-regulatory health-based
reference level of chemical
traces (usually in ppm) in
drinking water at which there
are no adverse health risks when
ingested over various periods of
time. Such levels are
established for one day, 10
days, long term and life-time
exposure periods. They contain a
large margin of safety. |
|
Health Assessment |
An
evaluation of available data on
existing or potential risks to
human health posed by a
Superfund site. The Agency for
Toxic Substances and Disease
Registry (ATSDR) of the
Department of Health and Human
Services (DHHS) is required to
perform such an assessment at
every site on the National
Priorities List. |
|
Health Based Cleanup Goal
|
A
media-specific contaminant
concentration derived from the
risk assessment process; used as
the goal for cleanup. |
|
Health Effects Assessment
Summary Tables (HEAST) |
A
tabular presentation of toxicity
information and values for
chemicals that is updated
quarterly. It summarizes interim
and verified RfDs and slope
factors as well as other
toxicity information for
specific chemicals. It contains
the most current sources of
supporting toxicity information
for chemicals that cannot be
found in the IRIS. |
|
Health Hazard |
A
chemical, mixture of chemicals
or a pathogen for which there is
statistically significant
evidence, based on at least one
study conducted in accordance
with established scientific
principles, that acute or
chronic effects may occur in
exposed personnel. |
|
Heat Exhaustion (Heat
Prostration) |
A
mild form of shock caused when
the circulatory system begins to
fail as a result of the body's
inadequate effort to give off
excessive heat. |
|
Heatstroke |
A
severe and sometimes fatal
condition resulting from the
failure of the
temperature-regulating capacity
of the body. It is caused by
prolonged exposure to the sun or
high temperatures. Reduction or
cessation of sweating is an
early symptom. Body temperatures
of 105°F or higher, rapid pulse,
hot and dry skin, headache,
confusion, unconsciousness, and
convulsions may occur.
Heatstroke is a TRUE MEDICAL
EMERGENCY, requiring immediate
transport to a medical facility.
|
|
Heavy Metals |
Metallic elements with high
atomic weights that can damage
living things at low
concentrations and tend to
accumulate in the food chain,
e.g., mercury, chromium,
cadmium, arsenic, and lead.
|
|
Henry's Law Constant (H)
|
Provides a measure of the extent
of chemical partitioning between
air and water at equilibrium.
The higher the constant, the
more likely a chemical is to
volatilize than to remain in
water. |
|
Heptachlor |
An
insecticide that was banned on
some food products in 1975 and
all food products in 1978. It
was allowed for use in seed
treatment until 1983. More
recently it was found in milk
and other dairy products in
Arkansas and Missouri where
dairy cattle were illegally fed
treated seed.
|
|
Herbicide |
A
chemical pesticide designed to
control or destroy plants,
weeds, or grasses. |
|
Herbivore |
An
animal that feeds on plants.
|
|
Heterogeneous |
Pertaining to a substance having
different characteristics in
different locations.
Non-uniform. For example, sand
with intermittent clay lenses.
Antonym |
|
Homogeneous |
|
|
Heterotrophic Organisms
|
Consumers such as humans and
animals, and decomposers such as
bacteria and fungi, that are
dependent on organic matter for
food.
|
|
High-Density Polyethylene (HDPE)
|
A
material used to make plastic
bottles and other products that
produces toxic fumes when
burned. |
|
High-to-Low Dose Extrapolation
|
Prediction of low exposure risk
to humans from the measured high
exposure, high risk data
involving rodents. |
|
Holding Pond |
A
pond or reservoir, usually made
of earth, built to store runoff.
|
|
Holding Time |
The
elapsed time expressed in days
from the date of receipt of the
sample by the contractor until
the date of its analysis.
|
|
Homogeneous |
Pertaining to a substance having
uniform characteristics
throughout. Uniform. Antonym -
Heterogeneous. |
|
Hot Zone |
See
Exclusion Zone. |
|
Household Waste (Domestic Waste)
|
Solid waste, composed of garbage
and rubbish, which normally
originated in a private home or
apartment house. Domestic waste
may contain a significant amount
of toxic or hazardous waste.
|
|
Human Equivalent Dose |
A
dose which, when administered to
humans, produces an effect equal
to that produced by a dose in
animals. |
|
Human Exposure Evaluation
|
Describing the nature and size
of the population exposed to a
substance and the magnitude and
duration of their exposure. The
evaluation could concern past,
current, or anticipated
exposures. |
|
Human Health Risk |
The
likelihood that a given exposure
or series of exposures may have
or will damage the health of
individuals. |
|
Hydraulic Conductivity (K)
|
A
measure of the ability of an
aquifer to transmit a fluid; it
is expressed as the volume of
water at the existing kinematic
viscosity that will move in a
unit time under a unit hydraulic
gradient through a unit area
measured at right angles to the
direction of flow. |
|
Hydraulic Gradient (i, dH/dX)
|
The
gradient or slope of the water
table, or of the potentiometric
surface, in the direction of the
greatest slope, generally
expressed in feet per mile.
|
|
Hydrocarbons (HC) |
Chemical compounds that consist
entirely of carbon and hydrogen.
|
|
Hydrogen (H, H2)
|
The
lightest of the chemical
elements, it forms organic
compounds with carbon. The
amount of dissolved hydrogen in
groundwater can also indicate
the redox state and pH of the
local environment. |
|
Hydrogen Sulfide (HS) |
Gas
emitted during organic
decomposition. Also a byproduct
of oil refining and burning.
Smells like rotten eggs and, in
heavy concentration, can kill or
cause illness. |
|
Hydrogenolysis |
A
reductive reaction in which a
carbon-halogen bond is broken,
and hydrogen replaces the
halogen substituent. |
|
Hydrogeologic Cycle |
The
natural processes recycling
water from the atmosphere down
to (and through) the earth and
back to the atmosphere again.
|
|
Hydrogeology |
The
geology of groundwater, and
related geological aspects of
surface water, with particular
emphasis on the chemistry and
movement of water. |
|
Hydrologic Cycle |
Movement or exchange of water
between the atmosphere and the
earth. |
|
Hydrology |
The
science that deals with the
properties of the waters of the
earth, their distribution on the
surface and underground, and the
circulation cycles involving
evaporation, precipitation,
flow, etc. |
|
Hydrometer |
An
instrument for determining
specific gravity. It can also be
used as a grain size test,
because grain size distribution
affects the specific gravity of
fluids according to the
distribution present. |
|
Hydrophilic |
"Water-liking"; having a strong
affinity for water. Substances
that can interact favorably with
polar water molecules. |
|
Hydrophobic |
"Water-fearing"; having a strong
aversion for water. Substances
that tend not to dissolve in
water. |
|
Hydropneumatic |
A
water system, usually small, in
which a water pump is
automatically controlled by the
air pressure in a compressed air
tank.
|
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Back to
Top |
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|
IJ
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|
Identification Code or EPA I.D.
Number |
The
unique code assigned to each
generator, transporter, and
treatment, storage, or disposal
facility by the USEPA to
facilitate identification and
tracking of chemicals or
hazardous waste.
|
|
Ignitable |
1)
A liquid that has a flash point
less than 140°F. 2) Capable of
burning or causing a fire. |
|
Immediately Dangerous to Life
and Health (IDLH) |
The
maximum level to which a healthy
individual can be exposed to a
chemical for 30 minutes and
escape without suffering
irreversible health effects or
impairing symptoms. Used as a
"Level of Concern." See Level of
Concern. |
|
Imminent Threat |
A
threat posed by a site if human
exposure in excess of applicable
human health or environmental
criteria is predictable prior to
implementation of an effective
remedial action or an operable
unit thereof.
|
|
Immiscible |
Refers to liquids which do not
form a single phase when mixed;
e.g. oil and water. Synonym -
Non-Aqueous Phase Liquid.
Antonym - Miscible. |
|
Impermeable |
Not
easily penetrated. The property
of a material or soil that does
not allow, or allows only with
great difficulty, the movement
or passage of water, particles
or chemicals. |
|
Incineration |
A
treatment technology involving
destruction of waste by
controlled burning at high
temperatures, e.g., burning
sludge to remove the water and
reduce the remaining residues to
a safe, non-burnable ash that
can be disposed of safely on
land, in some waters, or in
underground locations.
|
|
Incinerator |
Typically consists of a furnace
and stack unit used for a
variety of disposal activities
including the controlled burning
of medical waste, packaging and
varieties of municipal waste.
|
|
Incompatible Waste |
A
waste unsuitable for mixing with
another waste or material
because it may react to form a
hazard. |
|
Incremental Carcinogenic Risk
Level (ICR) |
The
potential for incremental
carcinogenic human health
effects due to exposure to the
chemical(s) of concern. |
|
Indicator |
1)
In biology, an organism,
species, or community whose
characteristics show the
presence of specific
environmental conditions. 2) In
chemistry, a substance that
shows a visible change, usually
of color, at a desired point in
a chemical reaction. 3) A device
that indicates the result of a
measurement, e.g., a pressure
gauge or a moveable scale. |
|
Indigenous |
1)
Living or occurring naturally in
a specific area or environment,
native. 2) For bioremediation,
microorganisms already living at
a site. |
|
Indirect Exposure Pathway
|
An
exposure pathway with at least
one intermediate release to any
media between the source and the
point(s) of exposure (for
example, chemicals of concern
from soil through groundwater to
the point(s) of exposure). |
|
Indoor Air |
The
breathing air inside a habitable
structure or conveyance. |
|
Indurated |
Rendered hard. |
|
Industrial Waste |
Unwanted materials from an
industrial operation; may be
liquid, sludge, solid, or
hazardous waste. |
|
Infauna |
1)
Benthic organisms that live in
or burrow through the bottom
sediment. 2) Organisms living
within a substrate. |
|
Infiltration |
1)
The penetration of water through
the ground surface into
sub-surface soil or the
penetration of water from the
soil into sewer or other pipes
through defective joints,
connections, or manhole walls.
2) The technique of applying
large volumes of wastewater to
land to penetrate the surface
and percolate through the
underlying soil. See
Percolation. |
|
Infiltration Gallery |
Covers a wide range of
subsurface groundwater
collection systems. They are
typically shallow in depth,
constructed with open-jointed or
perforated pipes that discharge
collected water into a
water-tight chamber from which
the water is pumped to treatment
facilities and into the
distribution system. Usually
located close to streams or
ponds. Can also be used to
collect water for remediation
purposes after it has passed
through an area of contamination
as a type of washing method.
|
|
Infiltration Rate |
The
quantity of water than can enter
the soil in a specified time
interval. |
|
Influent |
Water, wastewater, or other
liquid flowing into a reservoir,
basin, or treatment plant. |
|
Information Repositories
|
Collections of site information
that include items which are
related to the site, but may or
may not be suitable for
incorporation in the
administrative record. |
|
Ingestion |
The
introduction of a chemical into
the body through the mouth.
Inhaled chemicals may be trapped
in saliva and swallowed. Exposed
personnel should be prohibited
from smoking, eating, or
drinking except in designated
rest areas after being
decontaminated. |
|
Inhalation |
The
introduction of chemical vapors
or toxic products of combustion
into the body by way of the
respiratory system. Toxins may
be absorbed into the bloodstream
and carried to other internal
organs, or they may affect the
upper and/or lower respiratory
tract. Resulting respiratory
injuries include pulmonary edema
and respiratory congestion.
Inhalation is the most common
exposure route and often the
most damaging. |
|
Initial Site Characterization
(ISC) |
Completed after discovery of a
release from an Underground
Storage Tank (UST) and after any
initial abatement measures and
the site check have been
completed. The ISC should
assemble information into a
report on the site such as the
nature and estimated quantity of
release; surrounding
populations; water quality, use
and well locations; storm
water/wastewater systems;
climatology; land use; results
of the site check and initial
abatement measures; and results
of any free product removals.
Equivalent to a CERCLA
Preliminary Assessment (PA).
|
|
Injection Well |
A
well into which fluids or gases
are injected for purposes such
as waste disposal, improving the
recovery of crude oil, solution
mining, or delivering nutrients
to speed biodegradation of
chemicals in groundwater. |
|
Injection Zone |
A
geological formation receiving
fluids through a well. |
|
In Line Filtration |
Pre-treatment method in which
chemical coagulants are added
directly to the filter inlet
pipe. The chemicals are mixed by
the flowing water. Commonly used
in pressure filtration
installations. Eliminates need
for flocculation and
sedimentation. |
|
Innovative Treatment
Technologies |
Newly invented processes that
have been tested and used as
treatments for hazardous waste
or other contaminated materials,
but still lack enough
information about their cost and
how well they work to predict
their performance under a
variety of operating conditions.
They are often used because they
can offer cost-effective,
long-term solutions to cleanup
problems, they may provide an
alternative to land disposal or
incineration, and are often more
acceptable to surrounding
communities than some
established treatment
technologies. |
|
Inorganic Chemicals |
Chemical substances of mineral
origin, not usually having a
carbon structure. |
|
In Situ Remediation |
A
treatment process that can be
operated within the site of
contamination without bulk
excavation. Antonym - Ex Situ.
|
|
In Situ Respiration Test
|
Test used to provide rapid field
measurement of in situ
biodegradation rates to
determine the potential
applicability of bioventing at a
contaminated site and to provide
information for a full-scale
bioventing system design. |
|
In Situ Stripping |
Treatment system that removes or
"strips" volatile organic
compounds from contaminated
ground or surface water by
forcing an airstream through the
water and causing the compounds
to volatilize/evaporate.
|
|
Installation |
The
real property owned, formerly
owned, or leased by the Navy,
including a main base and any
associated contiguous real
properties identified by the
same real property number. |
|
Installation Restoration Program
(IR, IRP) |
Established in 1984 to help
identify, investigate, and
cleanup contamination on DOD
properties; conducted under the
auspices of CERCLA of 1980 and
SARA of 1986; the DOD equivalent
to the EPA Superfund program.
|
|
Institutional Controls |
The
restriction on use or access
(for example, fences, deed
restrictions, restrictive
zoning) to a site or facility to
eliminate or minimize potential
exposure to a chemical(s) of
concern. |
|
Instrument Detection Limit
|
1)
Under ideal conditions, that
concentration of analyte which
produces an output signal twice
the root mean square of the
background noise. 2) Three times
the standard deviation obtained
for the analysis of a standard
solution (each analyte in
reagent water) at a
concentration of 3x-5x
instrument detection limit, on
three nonconsecutive days with
seven consecutive measurements
per day. |
|
Intake |
A
measure of exposure expressed as
mass of a substance in contact
with the exchange boundary per
unit body weight per unit time
(e.g., mg chemical/kg/day). Also
termed the normalized exposure
rate; administered dose, and
applied dose. |
|
Integrated Exposure Assessment
|
Cumulative summation (over time)
of the magnitude of exposure to
a toxic chemical in all media.
|
|
Integrated Risk Information
System (IRIS) |
A
USEPA data base containing
verified RfDs, slope factors and
up-to-date health risk and USEPA
regulatory information for
numerous chemicals. IRIS is
USEPA's preferred source for
toxicity information for
Superfund. |
|
Interagency Agreements (IAG)
|
A
formal agreement between the
EPA, the state, and the Navy
that establishes objectives,
responsibilities, procedures,
and schedules for remediation at
NPL installations. The IAG must
be made formal within 180 days
of EPA's review of the RI/FS.
|
|
Interested Parties/Groups
|
Community members that live
and/or work in the affected
community that would be impacted
by the release or potential
release of a hazardous substance
prior to, or as part of
restoration activities at an IR
site. |
|
Interface |
The
common boundary between two
substances such as water and a
solid, water and a gas, or two
separate liquids such as water
and oil. |
|
Interim Action |
Those removal actions that only
partially address a problem or
only address the problem for a
short time. Interim actions
require further study and
possibly action, in addition to
the interim action. Interim
actions are most appropriate to
mitigate immediate threats while
allowing time for studies to be
conducted, as necessary to
determine a final solution.
|
|
Interim Corrective Measure
|
A
response action under RCRA to
mitigate fire and safety hazards
and to prevent further migration
of the contaminant(s). It may be
identified and implemented at
any time during the study or
design phase; limited in scope
and addresses only areas or
media for which a final remedy
will be developed by the RI/FS
process; should be consistent
with the final remedy for a
site. |
|
Interim (Permit) Status (IS)
|
Period during which treatment,
storage and disposal facilities
coming under RCRA in 1980 are
temporarily permitted to operate
while awaiting a permanent
permit. |
|
Interim Remedial Action (IRA)
|
A
response action under CERCLA to
mitigate fire and safety hazards
and to prevent further migration
of the contaminant(s). It may be
identified and implemented at
any time during the study or
design phase; limited in scope
and addresses only areas or
media for which a final remedy
will be developed by the RI/FS
process; should be consistent
with the final remedy for a
site. |
|
Internal Standards |
Compounds added to every
standard, blank, matrix spike,
matrix spike duplicate, sample
(for volatile), and sample
extract (for semivolatile) at a
known concentration prior to
analysis. Internal standards are
used as the basis for
quantitation of the target
compounds. |
|
Interstate Waters |
Waters that flow across or form
part of state or international
boundaries, e.g., the Great
Lakes, the Mississippi River, or
coastal waters. |
|
Interstices |
The
opening or pore spaces in a soil
or rock formation. In an
aquifer, they are filled with
water. |
|
Interstitial Monitoring
|
The
continuous surveillance of the
space between the walls of an
underground storage tank. |
|
Intrinsic |
1)
Originating or due to causes
within something. 2) Originating
and occurring wholly within
something. |
|
Intrinsic Bioremediation
|
The
in situ reduction of contaminant
concentrations resulting from
the destruction, loss, or
dilution of contaminant mass
(without human intervention) to
levels that do not pose a risk
to human health or the
environment. |
|
In-Well Aeration |
The
process of injecting gas into a
well to produce an in-well
airlift pump effect. |
|
Ion |
An
electrically charged atom that
can be drawn from waste water
during electrodialysis. |
|
Ion Exchange Treatment |
A
common water-softening method
often found on a large scale at
water purification plants that
remove some organics and radium
by adding calcium oxide or
calcium hydroxide to increase
the pH to a level where the
metals will precipitate out.
|
|
Ionic Strength |
A
measure of the concentration and
charge of ions in solution. The
ionic strength of a solution
affects the solubility of
compounds, most often increasing
the solubility. This means that
in the environment, chemicals
could be more soluble in a
"salt" solution than in pure
water.
|
|
Iron (Fe) |
A
malleable metal that is the
fourth most abundant by weight
of the elements that compose the
earth's crust. It is naturally
very abundant in the
environment. Mobility of iron in
water depends on its oxidation
state, whether it is in the
reduced form (II) or oxidized
form (III). Iron (II) is
generally more mobile in waters
void of dissolved oxygen. Iron
(III) is generally insoluble but
can exist in natural
organometallic or humic
compounds and colloidal forms.
The presence or lack of
dissolved oxygen has little
affect on iron (III), and this
form of iron has little effect
on aquatic life. The majority of
iron is likely to settle and
partition to bottom sediments.
It can be transported great
distances adsorbed to sediments
however. Iron in soil has low
mobility potential. Iron is an
essential nutrient to humans.
|
|
Irreversible Effect |
Effect characterized by the
inability of the body to
partially or fully repair injury
caused by a toxic agent. |
|
Irritant |
A
substance that can cause
irritation of the skin, eyes, or
respiratory system. Effects may
be acute from a single high
level exposure, or chronic from
repeated low-level exposures to
such compounds as chlorine,
nitrogen dioxide, and nitric
acid. |
|
Isolation Procedure |
The
process of limiting the number
of civilian and public service
personnel exposed to a hazardous
material. |
|
Isomer |
A
compound with the same atomic
composition and molecular weight
as another compound but
differing in molecular structure
and chemical or physical
properties. For example,
graphite (pencil lead) and
diamond are isomers of carbon.
Both are composed of pure
carbon, but exhibit very
different physical properties.
|
|
Isotope |
A
variation of an element that has
the same atomic number of
protons but a different weight
because of the number of
neutrons. Various isotopes of
the same element may have
different radioactive behaviors,
some are highly unstable. |
|
Isotropic / Isotropy |
Having identical properties in
all directions.
|
|
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K
|
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|
Karst |
A
geologic formation of irregular
limestone deposits with sinks,
underground streams, and
caverns. |
|
Kinetic Energy |
Energy possessed by a moving
body as a result of its motion.
|
|
Kinetic Rate Coefficient
|
A
number that describes the rate
at which a water constituent
such as a biochemical oxygen
demand or dissolved oxygen rises
or falls. |
|
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|
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L
|
|
|
Laboratory Control Sample
|
A
control sample of known
composition. Aqueous and solid
lab control samples are analyzed
using the same sample
preparation, reagents, and
analytical methods employed for
samples received. |
|
Lagoon |
1)
A shallow pond where sunlight,
bacterial action, and oxygen
work to purify wastewater; also
used for storage of wastewater
or spent nuclear fuel rods. 2)
Shallow body of water, often
separated from the sea by coral
reefs or sandbars. |
|
Land Application |
Discharge of wastewater onto the
ground for treatment or reuse.
See Infiltration. |
|
Land Ban |
Phasing out of land disposal of
most untreated hazardous wastes,
as mandated by the 1984 HSWA
amendments to RCRA. |
|
Landfarming |
1)
A disposal process in which
hazardous waste deposited on or
in the soil is naturally
degraded by microbes. 2) A
bioremediation technology in
which contaminated soil or
sediment is excavated and spread
on a pan with a built-in system
to collect any leachate. The
soils are periodically turned
over to mix air into the waste.
Moisture, nutrients, temperature
and pH are also controlled to
optimize the biodegradation
occurring
|
|
Landfills |
1)
Sanitary landfills are disposal
sites for non-hazardous solid
wastes spread in layers,
compacted to the smallest
practical volume, and covered by
material applied at the end of
each operating day. 2) Secure
chemical landfills are disposal
sites for hazardous waste,
selected and designed to
minimize the chance of release
of hazardous substances into the
environment. |
|
Langelier Index (LI) |
An
index reflecting the equilibrium
pH of water with respect to
calcium and alkalinity; used in
stabilizing water to control
both corrosion and scale
deposition. |
|
Large Quantity Generator
|
Person or facility generating
more than 2200 pounds of
hazardous waste per month. Such
generators produce about 90
percent of the nation's
hazardous waste, and are subject
to all RCRA requirements. |
|
Latency |
Time from the first exposure of
a chemical until the appearance
of a toxic effect. |
|
LC50/Lethal Concentration
|
Median level concentration, a
standard measure of toxicity. It
tells how much of a substance is
needed to kill half of a group
of experimental organisms in a
given time. See LD50. |
|
LD50/ Lethal Dose |
The
dose of a toxicant that will
kill 50 percent of the test
organisms within a designated
period. The lower the LD50, the
more toxic the compound. |
|
Leachate |
Water that collects contaminants
as it trickles through wastes,
pesticides or fertilizers.
Leaching may occur in farming
areas, feedlots, and landfills,
and may result in hazardous
substances entering surface
water, groundwater, or soil.
|
|
Leachate Collection System
|
A
system that gathers leachate and
pumps it to the surface for
treatment. |
|
Leaching |
The
process by which soluble
constituents are dissolved and
filtered through the soil by a
percolating fluid. See Leachate.
|
|
Lead (Pb) |
A
ductile, heavy metal. It occurs
naturally as a trace constituent
in rocks, soils, water, plants,
animals and air. It is used
widely in industry because of
its softness, resistance to
corrosion and radiation, and
high density. It is used in
storage batteries, gasoline
additives, pigments, alloys,
ammunition, and solder. Its use
has been sharply restricted or
eliminated by federal laws and
regulations. Most lead entering
natural waters will precipitate
to the sediment bottom as
carbonate or hydroxide
compounds. However, at low pH
and low organic conditions, it
is in its most soluble,
bioavailable and mobile form.
Sorption is the dominant
influence in soil. Mobility of
lead in soil is low and
therefore leaching to
groundwater or runoff is not a
predominant factor. Lead is not
readily taken up by plants and
does not appear to significantly
bioaccumulate in most fish.
Inhalation or ingestion of lead
can cause neurological, cardiac
and gastrointestinal problems.
It is a Group B2, possible human
carcinogen. |
|
Lead Agency |
The
location where the master copy
of the Administrative Record
File/Administrative Record is
established and maintained,
generally the Engineering Field
Division/Engineering Field
Activity (EFD/EFA).
|
|
Leakance |
The
ratio of vertical hydraulic
conductivity and the thickness
of a confining bed; this term is
used in the flow equations for
leaky aquifers with vertical
movement. |
|
Leaky Aquifer |
An
aquifer bounded above and below
by a semi-permeable layer so
that water from the aquifer
flows or leaks from the aquifer.
|
|
Legal Agreement |
A
means of setting project
milestones; current DON
environmental cleanup program
funding policy requires
incorporating relative risk
evaluations and DON
environmental restoration
funding controls. |
|
Leukogen |
A
substance that causes leukemia.
|
|
Lifetime Exposure |
Total amount of exposure to a
substance that a human would
receive in a lifetime (usually
assumed to be 70 years). |
|
Lift |
In
a sanitary landfill, a compacted
layer of solid waste and the top
layer of cover material. |
|
Ligands |
The
molecules surrounding a metal
ion in a complex ion. See
Chelate and Complexation. |
|
Light Non-Aqueous Phase Liquid
(LNAPL) |
A
liquid that does not dissolve in
water, and so forms a separate
phase, which is also lighter
than water and therefore floats
on the surface. Many petroleum
products are LNAPLs. |
|
Limited Degradation |
An
environmental policy permitting
some degradation of natural
systems but terminating at a
level well beneath an
established health standard.
|
|
Limiting Factor |
A
condition whose absence or
excessive concentration is
incompatible with the needs or
tolerance of a species or
population and which may have a
negative influence on their
ability to thrive and/or
survive.
|
|
Limnology |
The
study of the physical, chemical,
hydrological, and biological
aspects of fresh water bodies.
|
|
Lindane |
A
pesticide that causes adverse
health effects in domestic water
supplies and is toxic to
freshwater fish and aquatic
life.
|
|
Liner |
1)
A relatively impermeable barrier
designed to keep leachate inside
a landfill. Liner materials
include plastic and dense clay.
2) An insert or sleeve for sewer
pipes to prevent leakage or
infiltration.
|
|
Lipid Solubility |
The
maximum concentration of a
chemical that will dissolve in
fatty substances. Lipid soluble
substances are insoluble in
water. They will very
selectively disperse through the
environment via uptake in living
tissue. |
|
Liquefaction |
Changing a solid into a liquid.
|
|
Listed Waste |
Wastes listed as hazardous under
RCRA but which have not been
subjected to the Toxicity
Characteristic Listing Procedure
because the dangers they present
are considered self-evident.
|
|
Lithology |
The
large scale physical
characteristics of rocks and
sediments. |
|
Lithotroph |
An
organism that uses inorganic
carbon such as carbon dioxide or
bicarbonate as a carbon source
and an external energy source.
|
|
Littoral Zone |
1)
That portion of a body of fresh
water extending from the
shoreline lakeward to the limit
of occupancy of rooted plants.
2) The strip of land along the
shoreline between the high and
low water levels.
|
|
Long-Term Monitoring (LTM)
|
Site sampling and analysis
required to confirm that site
cleanup requirements continue to
be met after the Remedial Action
(RA) has been accomplished or
that site contaminant levels
continue to be below
concentrations which require RA.
LTM does not overlap (in time)
with the RA nor with LTO
(monitoring is included in RA or
LTO in years where either of
those phases is programmed).
|
|
Long-Term Operation (LTO) or
Long-Term O&M |
See
Remedial Action Operation. |
|
Lower Explosive Limit (LEL)
|
The
concentration of a compound in
air below which the mixture will
not ignite. |
|
Lowest Observed Adverse Effect
Level (LOAEL) |
In
dose-response experiments, the
lowest exposure level at which
there are statistically or
biologically significant
increases in frequency or
severity of adverse effects
between the exposed population
and its appropriate control
group. |
|
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M
|
|
|
Macrofauna |
A
general term referring to
benthic organisms more than 1 mm
in size. |
|
Magnesium (Mg) |
An
alkaline earth metal that is
very abundant in the
environment. Readily forms salts
with various metals and
halogens. When dissolved in
water, it can be used to
indicate salinity and
alkalinity. Contributes to hard
water in high concentrations. It
is an essential nutrient for
animals and humans. Not
generally considered toxic.
|
|
Magnetic Separation |
Use
of magnets to separate ferrous
materials from mixed municipal
waste streams. |
|
Manganese (Mn) |
A
brittle metal usually occurring
in nature with other metals like
iron. It is used in steel
alloys, dry-cell batteries,
electrical coils, other metallic
fabrication applications,
oxidizing agents, and as a food
additive. It is an essential
nutrient but can be harmful to
the central nervous system in
excessive amounts. |
|
Manifest |
The
form used for identifying the
quantity, composition, and the
origin, routing, and destination
of hazardous waste during its
transportation from the point of
generation to the point of
disposal, treatment, or storage.
|
|
Manifest System |
A
procedure in which hazardous
materials are identified and
tracked as they are produced,
treated, transported, and
disposed of by a series of
permanent, linkable, descriptive
documents (e.g., manifests).
|
|
Margin of Safety |
Maximum amount of exposure
producing no measurable effect
in animals (or studied humans)
divided by the actual amount of
human exposure in a population.
|
|
Marsh |
A
type of wetland that does not
accumulate appreciable peat
deposits and is dominated by
herbaceous vegetation. Marshes
may be either fresh or
saltwater, tidal or non-tidal.
See Wetlands. |
|
Material Safety Data Sheet
(MSDS) |
A
compilation of information
required under the OSHA
Communication Standard on the
identity of hazardous chemicals,
health, and physical hazards,
exposure limits, precautions,
and handling information.
Section 311 of SARA requires
facilities to submit MSDSs under
certain circumstances. |
|
Matrix |
The
predominant material comprising
the sample to be analyzed. The
most common matrices are water,
soil/sediment, and sludge.
|
|
Matrix Spike (MS) |
The
process of adding a known amount
of analyte to a sample and
analyzing the sample. The amount
of analyte recovered is
calculated as a percent
recovery. This technique is used
to assess accuracy of analysis.
|
|
Matrix Spike Duplicate (MSD)
|
A
second matrix spike is compared
to the results of the first
matrix spike to assess precision
of the analysis. |
|
Maximum Contaminant Level (MCL)
|
The
maximum permissible level of a
contaminant in water delivered
to any user of a public system.
MCLs are enforceable standards.
|
|
Maximum Contaminant Level Goal
(MCLG) |
Under the Safe Drinking Water
Act, a non-enforceable
concentration of a contaminant,
set at the level at which no
known or anticipated adverse
effects on human health occur
and which allows an adequate
safety margin. The MCLG is
usually the starting point for
determining the regulated
Maximum Contaminant Level. See
Maximum Contaminant Level. |
|
Maximum Tolerated Dose |
The
maximum dose that an animal
species can tolerate for a major
portion of its lifetime without
significant impairment or toxic
effect other than
carcinogenicity. |
|
Measurement Endpoint |
Quantitative expressions of an
observed or measured effect of
Environmental Contaminants of
Concern. They may be identical
to assessment endpoints (e.g.,
measurement of abundance of
fish), or they may be used as
surrogates for assessment
endpoints (e.g., toxicity test
endpoints).
|
|
Mechanical Aeration |
Use
of mechanical energy to inject
air into water to cause a waste
stream to absorb oxygen. |
|
Mechanical Stress |
The
result of a transfer of energy
when one object physically
contacts or collides with
another. Indications would be
punctures, gouges, breaks, or
tears in the container. |
|
Media |
Specific environments, i.e.,
air, water, or soil, which are
the subject of regulatory
concern and activities. |
|
Media-Specific Half-Life
|
Provides a relative measure of
the persistence of a chemical in
a given medium, although actual
values can vary greatly
depending on site-specific
conditions. The greater the
half-life, the more persistent a
chemical is likely to be. |
|
Medical Surveillance |
A
periodic comprehensive review of
a worker's health status;
acceptable elements of such
surveillance program are listed
in the Occupational Safety and
Health Administration standards
for asbestos. |
|
Melting Point (MP) |
The
temperature at which a solid
changes its phase to a liquid.
This temperature is also the
freezing point depending on the
direction of the change. For
mixtures, a melting point range
may be given. |
|
Mercury (Hg) |
Exists as a silvery, heavy
liquid or as a heavy metal. It
forms various insoluble salts
and complex compounds with
organic and inorganic chemicals.
It is used for amalgams,
catalysts, electrical
apparatuses, instruments such as
thermometers and barometers, and
in nuclear power plants. Mercury
released to the environment will
remain indefinitely. It does not
biodegrade but can be
biotransformed into various
different states. Its solubility
and state depends heavily on the
pH and redox state of the local
environment. The toxicity,
mobility, solubility and other
properties depend upon the state
the mercury is in, for example
whether it forms an insoluble
salt with another element or
whether it has formed a complex
organometallic compound like
methyl mercury, which is the
most hazardous and stable state
of mercury. Bioaccumulation is a
major concern. See Heavy Metals.
|
|
Mesotrophic |
Reservoirs and lakes which
contain moderate quantities of
nutrients and are moderately
productive in terms of aquatic
animal and plant life. |
|
Metabolic Byproduct |
A
product of the reaction between
an electron donor and an
electron acceptor. Metabolic
byproducts include volatile
fatty acids, daughter products
of chlorinated aliphatic
hydrocarbons, methane, and
chloride.
|
|
Metabolic Intermediate |
A
chemical produced by one step in
a multistep biotransformation.
|
|
Metabolism |
The
chemical reactions in living
cells that convert food sources
to energy and new cell mass.
|
|
Metabolites |
Any
substances produced by
biological processes, such as
those from pesticides. |
|
Meteorology |
The
science that deals with the
atmosphere and atmospheric
phenomena; the study of weather.
|
|
Methane (CH4)
|
A
colorless, nonpoisonous,
flammable gas created by
anaerobic decomposition of
organic compounds. |
|
Methanogen |
A
microorganism that exists in
anaerobic environments and
produces methane as the end
product of its metabolism.
Methanogens use carbon dioxide
or simple carbon compounds such
as methanol as an electron
acceptor. |
|
Methanol |
An
alcohol that can be used as an
alternative fuel or as a
gasoline additive. It is less
volatile than gasoline; when
blended with gasoline it lowers
the carbon monoxide emissions
but increases hydrocarbon
emissions. Used as pure fuel,
its emissions are less
ozone-forming that those from
gasoline. |
|
Method (Analytical) Qualifier
|
Symbols added as a suffix to
analytical results to identify
the analytical method used to
measure the analyte: |
|
A |
Flame Atomic Absorption (AA).
|
|
AS |
Semiautomated
Spectrophotometric. |
|
AV |
Automated Cold Vapor AA. |
|
C |
Manual Spectrophotometric. |
|
CV |
Manual Cold Vapor AA. |
|
F |
Furnace AA. |
|
NC |
Not
calculated as per protocols.
|
|
NR |
The
analyte is not required to be
analyzed.
|
|
P |
ICP. |
|
T |
Titrimetric. |
|
Method Blank |
Contaminant free water, or
appropriate matrix, that is
taken through the entire
analytical process to determine
if there is any contamination
associated with the analytical
procedures. |
|
Method Detection Limit (MDL)
|
The
minimum concentration of a
substance that can be measured
and reported with 99% confidence
that the analyte concentration
is greater than zero and is
determined from analysis of a
sample in a given matrix
containing the analyte. |
|
Methoxychlor |
Pesticide that causes adverse
health effects in domestic water
supplies and is toxic to
freshwater and marine aquatic
life.
|
|
Microbial Growth |
The
activity and growth of
microorganisms such as bacteria,
algae, diatoms, plankton, and
fungi. |
|
Microclimate |
The
localized climate conditions
within an urban area or
neighborhood. |
|
Microcosm |
A
laboratory vessel set up to
resemble as closely as possible
the conditions of a natural
environment. |
|
Micron (ðmm) |
A
unit of length equal to one
millionth (10-6) of a
meter. Also called a micrometer.
|
|
Microorganism |
Living organisms so small that
individually they can usually
only be seen through a
microscope. |
|
Migration Pathway |
A
pathway by which a hazardous
material is transported at, or
from, a disposal site. |
|
Migration Pathway Factor (MPF)
|
A
measure of the movement or
potential movement of
contamination away from the
original source. |
|
Mineralization |
The
complete conversion of an
organic compound to inorganic
products (principally water and
carbon dioxide). |
|
Mining of an Aquifer |
Withdrawal of groundwater over a
period of time that exceeds the
rate of recharge to the aquifer.
|
|
Miscible |
Two
or more liquids or gases that
can be mixed and will remain
mixed under normal conditions,
e.g., alcohol and water. Antonym
- Immiscible. |
|
Missed Detection |
The
situation that occurs when a
test indicates that a tank is
"tight" when in fact it is
leaking. |
|
Mitigation |
Measures taken to reduce adverse
impacts on the environment.
|
|
Mixed Waste |
Waste that contains both
hazardous waste and source,
special nuclear, or by-product
material subject to the Atomic
Energy Act of 1954. |
|
Mobile Incinerator Systems
|
Hazardous waste incinerators
that can be transported from one
site to another. |
|
Mobile Source |
Any
non-stationary source of air
pollution such as cars, trucks,
motorcycles, buses, airplanes,
locomotives, etc. |
|
Modeling |
An
investigative technique using a
mathematical or physical
representation of a system or
theory that accounts for all or
some of its known properties.
Models are often used to test
the effect of changes of system
components on the overall
performance of the system. |
|
Modifying Factor (MF) |
In
toxicity assessments, a number
that reflects a professional
assessment of additional
uncertainties in the critical
study and in the entire database
for the chemical not explicitly
addressed by the uncertainty
factors. |
|
Mole (mol) |
A
mass of a compound defined as
Avogadro's Number (6.022 X 1023)
of atoms or molecules. |
|
Molecular Weight (MW) |
(mass) The sum of atomic masses
(in atomic mass units 1 amu =
mass of 12C atom as
standard) of the atoms present
in a molecule. |
|
Molecule |
The
smallest division of a compound
that still retains or exhibits
all the properties of the
substance. |
|
Monitoring |
1)
Periodic or continuous
surveillance or testing to
determine the level of
compliance with statutory
requirements and/or pollutant
levels in various media or in
humans, plants, and animals. 2)
Used to track the presence,
migration, or threat posed by
contaminants at a site; may be
used at a site between response
actions or when no other
response action is appropriate
until information or site status
changes. |
|
Monitoring Well (MW) |
1)
A well used to obtain water
quality samples or measure
groundwater levels. 2) Well
drilled at a hazardous waste
management facility or Superfund
site to collect groundwater
samples for the purpose of
physical, chemical, or
biological analysis to determine
the amounts, types, and
distribution of contaminants in
the groundwater beneath the
site. |
|
Monooxygenase |
A
microbial enzyme that catalyzes
reactions in which one atom of
the oxygen molecule is
incorporated into a product and
the other atom appears in water.
|
|
Monte Carlo Simulation |
A
procedure to estimate the value
and uncertainty of the result of
a calculation when the result
depends on a number of factors,
each of which is also uncertain.
|
|
Morbidity |
Rate of disease incidence. |
|
Most Probable Number (MPN)
|
The
most probable number of
organisms per unit volume of
sample water. |
|
Mudballs |
Round material that forms in
filters and gradually increases
in size when not removed by
backwashing. |
|
Mulch |
A
layer of material (wood chips,
straw, leaves, etc.) placed
around plants to hold moisture,
prevent weed growth, and enrich
or sterilize the soil. |
|
Multiple Use |
Use
of land for more than one
purpose; i.e., grazing of
livestock, watershed and
wildlife protection, recreation,
and timber production. Also
applies to use of bodies of
water for recreational purposes,
fishing, and water supply. |
|
Mutagen |
An
agent that causes a permanent
genetic change or transformation
in a cell other than that which
occurs during normal genetic
recombination. |
|
Mutagenicity |
The
capacity of a chemical or
physical agent to cause
permanent alternation. |
|
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N
|
|
|
Navy Assessment and Control Of
Installation Pollutants (NACIP)
|
The
Navy’s original environmental
restoration program, replaced by
the Installation Restoration
Program in 1986. |
|
National Estuary Program
|
A
program established under the
Clean Water Act Amendments of
1987 to develop and implement
conservation and management
plans for protecting estuaries
and restoring and maintaining
their chemical, physical, and
biological integrity, as well as
controlling point and nonpoint
pollution sources. |
|
National Oil and Hazardous
Substances Contingency Plan
(NOHSCP/NCP) |
40
Code of Federal Regulations 300
establishes EPA's response
policy and lays out the key
response steps for implementing
CERCLA. The regulation guides
determination of the sites to be
corrected under both the
Superfund program and the
program to prevent or control
spills into surface waters or
elsewhere. |
|
National Pollutant Discharge
Elimination System (NPDES)
|
A
provision of the Clean Water Act
which prohibits discharge of
pollutants into waters of the
United States unless a special
permit is issued by EPA, a
state, or, where delegated, a
tribal government on an Indian
reservation. |
|
National
Priorities List (NPL)
|
The
list, compiled by EPA pursuant
to CERCLA section 105, of
uncontrolled or abandoned
hazardous substance releases in
the U.S. that are priorities for
long-term remedial evaluation
and response. The NPL is a
compilation of sites scoring
28.5 or higher on the EPA HRS or
HRS2. EPA is required to update
the NPL at least once a year. A
site must be on the NPL to
receive money from the Trust
Fund for remedial action. |
|
National Response Center (NRC)
|
The
federal operations center that
receives notifications of all
releases of oil and hazardous
substances into the environment;
open 24 hours a day, it is
operated by the US Coast Guard,
which evaluates all reports and
notifies the appropriate agency.
|
|
National Response Team (NRT)
|
Representatives of 13 federal
agencies that, as a team,
coordinate federal responses to
nationally significant incidents
of pollution - an oil spill, a
major chemical release, or a
Superfund response action - and
provide advice and technical
assistance to the responding
agency(ies) before and during a
response action. |
|
Natural Attenuation |
Refers to naturally-occurring
processes in soil and
groundwater environments that
act without human intervention
to reduce the mass, toxicity,
mobility, volume, or
concentration of contaminants in
those media. These in-situ
processes include
biodegradation, dispersion,
dilution, adsorption,
volatilization, and chemical or
biological stabilization or
destruction of
contaminants.(USEPA OSWER, 1996)
|
|
Natural Resource |
As
defined by CERCLA, land, fish,
wildlife, biota, air, water,
groundwater, drinking water
supplies, and other such
resources belonging to, managed
by, held in trust by,
appertaining to, or otherwise
controlled by the U.S.,
including the resources of the
fishery conservation/zone
established by the Magnuson
Fishery Conservation and
Management Act of 1976, any
State or local government, any
foreign government, any Indian
Tribe, or, if such resources are
subject to a trust restriction
on alienation, any member of an
Indian Tribe. |
|
Natural Resource Damage
Assessment (NRDA) |
A
damage assessment conducted by
one or more trustees if response
action will not sufficiently
restore or protect natural
resources damaged by release.
The purpose is to determine the
appropriate level of
compensation from a responsible
party to trustee resources.
|
|
Natural Resource Trustees (NRTs)
|
Federal trustees with statutory
responsibilities with regard to
protection or management of
natural resources or stewardship
responsibilities as a manager of
Federally owned land; trustees
may also be state agencies or
Indian tribes. |
|
Navigable Waters |
1)
As defined by 40 CFR 110.1, the
waters of the U.S., including
the territorial seas. The term
includes: A) All waters that are
currently used, were used in the
past, or may be susceptible to
use in interstate or foreign
commerce, including all waters
that are subject to the ebb and
flow of the tide; B) Interstate
waters, including interstate
wetlands; C) All other waters
such as intrastate lakes,
rivers, streams (including
intermittent streams), mudflats,
sandflats, and wetlands, the
use, degradation, or destruction
of which would affect or could
affect interstate or foreign
commerce including any such
waters: a) That are or could be
used by interstate or foreign
travelers for recreational or
other purposes; b) From which
fish or shellfish are or could
be taken and sold in interstate
or foreign commerce; c) That are
used or could be used for
industrial purposes by
industries in interstate
commerce; D) All impoundments of
waters otherwise defined as
navigable waters under this
section; E) Tributaries of
waters identified in A) through
D) of this definition, including
adjacent wetlands; and F)
Wetlands adjacent to waters
identified in A) through E) of
this definition provided that
waste treatment systems (other
than cooling ponds meeting the
criteria of this paragraph) are
not waters of the U.S. 2)
Traditionally, waters
sufficiently deep and wide for
navigation by all, or specified
vessels; such waters in the
United States come under federal
jurisdiction and are protected
by certain provisions of the
Clean Water Act. |
|
Necrosis |
Death of plant or animal cells
or tissues. In plants, necrosis
can discolor stems or leaves or
kill a plant entirely. |
|
Nephelometric |
A
means of measuring turbidity in
a sample by passing light
through a sample and measuring
the amount of light deflected.
|
|
Neritic |
The
coastal sea from the low tide
line to a depth of 100 fathoms,
generally waters of the
continental shelf. |
|
Neutralization |
1)
Decreasing the acidity or
alkalinity of a substance by
adding alkaline or acidic
materials, respectively. 2) The
process of neutralizing a
hazardous material spill by
applying another material to the
spill which will react
chemically with it to form a
less harmful substance. 3)
Treatment of corrosive hazardous
wastes to yield a pH near 7.
|
|
Neutralizing Agents |
Those materials which can be
used to neutralize the effects
of a corrosive material. |
|
Nickel (Ni) |
A
hard, malleable, ductile metal.
It occurs naturally in all parts
of the environment including
plants and animals. It is used
in alloys, electrical catalysts
for hydrogenation of oils,
coins, and magnetic and
electrical contacts. Nickel can
be soluble or insoluble in water
depending on the chemical and
physical properties of the water
body. In soil, it is extremely
persistent. It can cause
dermatitis, and ingestion can
cause nausea and vomiting.
Nickel is a Group A, human
carcinogen. |
|
Nitrate (NO3)
|
1)
A salt or ester of nitrous acid.
Concentrations greater than 45
ppm can be toxic. 2)
Intermediate breakdown product
of biological wastes. Common
component of nutrient loading in
aquatic environments. 3) Vital
nutrient for plant growth. 4)
Inorganic fertilizer that enters
water supply sources from septic
systems, animal feed lots,
agricultural fertilizers,
manure, industrial waste waters,
sanitary landfills and garbage
dumps.
|
|
Nitric Oxide (NO) |
A
gas formed by combustion under
high temperature and high
pressure in an internal
combustion engine; changes into
nitrogen dioxide in the ambient
air and contributes to
photochemical smog. |
|
Nitrification |
The
process whereby ammonia in
wastewater is oxidized to
nitrite and then to nitrate by
bacterial or chemical reactions.
|
|
Nitrite (NO2,
aqueous) |
1)
An intermediate in the process
of nitrification. 2) Nitrous
oxide salts used in food
preservation. |
|
Nitrogen (N) |
Can
exist as a gas or dissolved in
solution, nitrogen forms various
environmentally significant
compounds with oxygen. |
|
Nitrogen Dioxide (NO2,
gaseous) |
The
result of nitric oxide combining
with oxygen in the atmosphere;
major component of photochemical
smog. |
|
Nitrogen Oxide (NOx) |
Product of combustion from
transportation and stationary
sources and a major contributor
to the formation of ozone in the
troposphere and to acid
deposition. |
|
No Further Action (NFA)
|
Applies to any site where the
possibility of contamination no
longer exists and, therefore,
will require no additional
remedial action. |
|
No Further Response Action
Planned (NFRAP) |
CERCLA sites that do not warrant
moving further in the site
evaluation process; a site that
does not pose significant threat
to public health or the
environment; decision must be
documented and may be reversible
if future information reveals
additional remedial action is
warranted. The Navy forwards the
decision document to the
regulators for concurrence.
|
|
No Observable Adverse Effect
Level (NOAEL) |
1)
In dose-response experiments, an
exposure level at which there
are no statistically or
biologically significant
increases in the frequency or
severity of adverse effects
between the exposed population
and its appropriate control;
some effects may be produced at
this level, but they are not
considered to be adverse, nor
precursors to specific adverse
effects. In an experiment with
more than one NOAEL, the
regulatory focus is primarily on
the highest one, leading to the
common usage of the term NOAEL
to mean the highest exposure
level without adverse effects.
2) From long-term toxicological
studies of agriculture chemical
active ingredients, levels which
indicate a safe, lifetime
exposure level for a given
chemical. Used to establish
tolerance for human diets. |
|
No Observed Effect Level (NOEL)
|
In
dose-response experiments, an
exposure level at which there
are no statistically or
biologically significant
increases in the frequency or
severity of any effect between
the exposed population and its
appropriate control. |
|
No Till |
Planting crops without prior
seedbed preparation, into an
existing cover crop, sod, or
crop residues, and eliminating
subsequent tillage operations.
|
|
Noble Metal |
Chemically inactive metal such
as gold; does not corrode
easily. |
|
Non-Carcinogen |
A
chemical classification for the
purposes of risk assessment
based on either inadequate
toxicological data or no
evidence of carcinogenicity
according to USEPA 1986
Guidelines for Risk Assessment,
in which non-carcinogens are
summarized as follows: Group
D: Not classifiable as to
human carcinogenicity:
Inadequate human and animal
evidence for carcinogenicity or
no available data. Group E:
Evidence of non-carcinogenicity
in humans: No evidence for
carcinogenicity in at least two
adequate animal tests or in both
adequate human epidemiological
and animal studies. |
|
Non-Conventional Pollutant
|
Any
pollutant not statutorily listed
or which is poorly understood by
the scientific community. |
|
Non-Degradation |
An
environmental policy which
disallows any lowering of
naturally occurring quality
regardless of preestablished
health standards.
|
|
Non-Flowing Artesian Well
|
An
artesian well in which the head
is not sufficient to raise water
to the land surface at the well
site. |
|
Non-Point Source |
Diffuse pollution sources (i.e.,
without a single point of origin
or not introduced into a
receiving stream from a specific
outlet). The pollutants are
generally carried off the land
by storm water. Common nonpoint
sources are agriculture,
forestry, urban, mining,
construction, dams, channels,
land disposal, saltwater
intrusion, and city streets.
|
|
Nonpolar |
Describing a substance or
molecule in which the positive
and negative electrical charges
coincide, as opposed to polar
molecules in which the charges
are permanently separated.
Nonpolar substances are
generally insoluble and
immiscible in water, because
water is polar. Most hydrocarbon
liquids are nonpolar. |
|
Non-Potable |
Water that is unsafe or
unpalatable to drink because it
contains objectionable
pollution, contamination,
minerals, or infective agents.
|
|
Notice of Deficiency |
An
EPA request to a facility owner
or operator requesting
additional information before a
preliminary decision on a permit
application can be made. |
|
Notice of Intent to Deny
|
Notification by EPA of its
preliminary intent to deny a
permit application. |
|
Nucleophile |
A
chemical reagent that reacts by
forming covalent bonds with
electronegative atoms and
compounds. |
|
Nutrient |
Any
substance assimilated by living
things that promotes growth. The
term is generally applied to
nitrogen and phosphorus in
wastewater, but is also applied
to other essential and trace
elements.
|
|
Nutrient Amendment |
Chemical or organic fertilizer,
usually rich in nitrogen,
phosphorus, or potassium, that
is added to support the life and
growth of microorganisms in a
biopile or other application.
|
|
Nutrient Pollution |
Contamination of water resources
by excessive inputs of
nutrients. In surface waters,
excess algal production is a
major concern.
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O
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Obligate Aerobe |
Microorganisms that can use only
oxygen as an electron acceptor.
Thus, the presence of molecular
oxygen is a requirement for
these microbes. |
|
Obligate Anaerobe |
Microorganisms that grow only in
the absence of oxygen; the
presence of molecular oxygen
either inhibits growth or kills
the organism. For example,
methanogens are very sensitive
to oxygen and can live only
under strictly anaerobic
conditions. Sulfate reducers, on
the other hand, can tolerate
exposure to oxygen, but cannot
grow in its presence. |
|
Occupational Exposure |
Reasonably anticipated skin,
eye, mucous membrane, or
parental contact with blood or
other potentially infectious
materials that results from the
performance of an employee's
duties. |
|
Octanol-Water Diffusion
Coefficient (Kow)
|
Provides a measure of the extent
of chemical partitioning between
octanol and water at
equilibrium. The greater the Kow,
the more likely a chemical is to
partition to octanol than to
remain in water. Octanol is used
as a surrogate for lipids (fat),
therefore Kow can be
used to predict bioconcentration
in aquatic organisms.
|
|
Off-Base Contamination |
Contaminants found to be
migrating off the installation
or coming onto the installation
from off-base sources. |
|
Off-Gas |
Gaseous effluent, possibly
containing contaminant vapors,
that leaves a process, typically
from a point source during
process operations. |
|
Off-Site Facility |
A
hazardous waste treatment,
storage or disposal area that is
located away from the generating
site. |
|
Offstream Uses |
Water withdrawn from surface or
groundwater sources for use at
another place. |
|
Oil Fingerprinting |
A
method that identifies sources
of oil and allows spills to be
traced to their source. |
|
Oil Spill |
An
accidental or intentional
discharge of oil which reaches
bodies of water. Can be
controlled by chemical
dispersion, combustion,
mechanical containment, and/or
adsorption. Spills from tanks
and pipelines can also occur
away from water bodies,
contaminating the soil, getting
into sewer systems and
threatening underground water
sources. |
|
Oil/Water Separator (OWS)
|
Engineered units that skim oil
from water. |
|
Oncogenic |
A
substance that causes tumors,
whether benign or malignant.
|
|
On-Scene Coordinator (OSC)
|
The
predesignated EPA, Coast Guard,
or Department of Defense
official who coordinates and
directs Superfund removal
actions or Clean Water Act oil
or hazardous spill response
actions. |
|
On-Site |
According to the NCP, the aerial
extent of contamination and all
suitable areas in very close
proximity to the contamination
necessary for implementation of
the response action. |
|
On-Site Facility |
A
hazardous waste treatment,
storage or disposal area that is
located on the generating site.
|
|
One-Hit Model |
Mathematical model based on the
biological theory that a single
"hit" of some minimum critical
amount of a carcinogen at a
cellular target such as DNA can
initiate an irreversible series
of events, eventually leading to
a tumor. |
|
Open Burning |
Uncontrolled fires in an open
dump. |
|
Open Dump |
An
uncovered site used for disposal
of waste without environmental
controls. See Dump. |
|
Operable Unit (OU) |
A
discrete action that comprises
an incremental step toward
comprehensively addressing site
problems; an action that
manages, eliminates, or
mitigates a release, threat of a
release, or pathway of exposure.
A typical operable unit would be
removal of drums and tanks from
the surface of a site. Can also
include action at a collection
of sites to be treated together,
often because of similar cleanup
requirements. |
|
Operation And Maintenance (O&M)
|
1)
Activities conducted after a
Superfund site action is
constructed to ensure that the
action is effective. 2) Actions
taken after construction to
assure that facilities
constructed to treat wastewater
will be properly operated and
maintained to achieve normative
efficiency levels and prescribed
effluent limitations in an
optimum manner. 3) On-going
asbestos management plan in a
school or other public building,
including regular inspections,
various methods of maintaining
asbestos in place, and removal
when necessary. |
|
Opportunistic Species |
1)
Organisms able to exploit
temporary habitats or
conditions. 2) A species that
has a life history characterized
by short life span, short
development time to maturity,
high death rate, and many
reproductive cycles per year.
|
|
Organic |
1)
Referring to or derived from
living organisms. 2) Pertaining
or relating to a compound
containing carbon, especially as
an essential component; organic
compounds usually have hydrogen
bonded to the carbon atom. |
|
Organic Carbon Diffusion
Coefficient (Koc)
|
Provides a measure of the extent
of chemical partitioning between
organic carbon and water at
equilibrium. The higher the Koc,
the more likely a chemical is to
bind to soil or sediment than to
remain in water. |
|
Organic Chemicals/Compounds
|
Animal or plant-produced
substances containing mainly
carbon, hydrogen, nitrogen, and
oxygen. |
|
Organic Matter |
Carbonaceous waste contained in
plant or animal matter and
originating from domestic or
industrial sources. |
|
Organism |
Any
form of animal or plant life.
|
|
Osmosis |
The
passage of a liquid from a weak
solution to a more concentrated
solution across a semipermeable
membrane that allows passage of
the solvent (water) but not the
dissolved solids. |
|
Outfall |
The
place where effluent is
discharged into receiving
waters. |
|
Overburden |
Rock and soil cleared away
before construction or mining.
|
|
Overdraft |
The
pumping of water from a
groundwater basin or aquifer in
excess of the supply flowing
into the basin; results in a
depletion or "mining" of the
groundwater in the basin. See
Mining of an Aquifer.
|
|
Oxidant/Oxidizer |
A
substance containing oxygen that
reacts chemically in air to
produce a new substance; the
primary ingredient of
photochemical smog.
|
|
Oxidation |
1)
Loss of electrons from a
compound, such as an organic
contaminant. The oxidation can
supply energy that
microorganisms use for growth.
Often (but not always),
oxidation results in the
addition of an oxygen atom
and/or the loss of a hydrogen
atom. 2) The addition of oxygen
that breaks down organic waste
or chemicals such as cyanides,
phenols, and organic sulfur
compounds in sewage by bacterial
and chemical means. |
|
Oxidation-Reduction Potential
(ORP) |
The
electric potential required to
transfer electrons from one
compound or element (the
oxidant) to another compound or
element (the reductant); used as
a qualitative measure of the
state of oxidation in water
treatment systems. |
|
Oxygen (O, O2)
|
Can
exist as a gas or dissolved in
solution. Oxygen forms various
inorganic compounds with metals
as well as organic compounds
with carbon, hydrogen, nitrogen
and other elements. O2
(gas) is vital to life whereas O3,
ozone, can be harmful due to its
ability to oxidize biological
tissue, metals, organic
compounds and other materials.
See Ozone.
|
|
Oxygen Use Rate |
Rate of oxygen consumption due
to biological and chemical
action (used to determine
respiration rate when the
chemical oxygen demand is
negligible). |
|
Oxygenated Solvent |
An
organic solvent containing
oxygen as part of the molecular
structure. Alcohols and ketones
are oxygenated compounds often
used as paint solvents. |
|
Ozonation |
Application of ozone to water
for disinfection or for taste
and odor control. |
|
Ozonator |
A
mechanical device that creates
ozone. |
|
Ozone (O3) |
Found in two layers of the
atmosphere, the stratosphere and
the troposphere. In the
stratosphere (the atmospheric
layer 7 to 10 miles or more
above the earth's surface) ozone
is a natural form of oxygen that
provides a protective layer
shielding the earth from
ultraviolet radiation. In the
troposphere (the layer extending
up 7 to 10 miles from the
earth's surface), ozone is a
chemical oxidant and major
component of photochemical smog.
It can seriously impair the
respiratory system and is one of
the most widespread of all the
criteria pollutants for which
the Clean Air Act required EPA
to set standards. Ozone in the
troposphere is produced through
complex chemical reactions of
nitrogen oxides, which are among
the primary pollutants emitted
by combustion sources;
hydrocarbons, released into the
atmosphere through the
combustion, handling and
processing of petroleum
products; and sunlight.
|
|
Ozone Depletion |
Destruction of the stratospheric
ozone layer which shields the
earth from ultraviolet radiation
harmful to life. This
destruction of ozone is caused
by the breakdown of certain
chlorine and/or bromine
containing compounds
(chlorofluorocarbons or halons)
when they reach the stratosphere
and then catalytically destroy
ozone molecules. |
|
Ozone Hole |
A
thinning break in the
stratospheric ozone layer. The
designation of "ozone hole" is
made when the detected amount of
depletion exceeds fifty percent.
Seasonal ozone holes have been
observed over both the Antarctic
region and the Arctic region and
part of Canada and the extreme
northeastern United States.
|
|
Ozone Layer |
The
protective layer in the
stratosphere, beginning about 7
to 10 miles above the ground,
that absorbs some of the sun's
ultraviolet rays, thereby
reducing the amount of
potentially harmful radiation
reaching the earth's surface.
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Packaging |
The
assembly of one or more
containers and any other
components necessary to assure
minimum compliance with a
program's storage and shipment
packaging requirements. Also,
the containers, etc., involved.
|
|
Packed Tower |
A
pollution control device that
forces dirty air through a tower
packed with crushed rock or wood
chips while liquid is sprayed
over the packing material. The
pollutants in the air stream
either dissolve or chemically
react with the liquid. |
|
Palatable Water |
Water at a desirable temperature
that is free from objectionable
tastes, odors, colors, and
turbidity. |
|
Parameter |
A
variable, measurable property
whose value is a determinant of
the characteristics of a system;
e.g., temperature, pressure, and
density are parameters of the
atmosphere. |
|
Partially Penetrating Well
|
A
well in which the screened
length is less than the
saturated thickness of the
aquifer. |
|
Particulates |
1)
Fine liquid or solid particles
such as dust, smoke, mist,
fumes, or smog found in air or
emissions. 2) Very small solids
suspended in water. They vary in
size, shape, density, and
electrical charge, and can be
gathered together by coagulation
and flocculation. |
|
Partition Coefficient |
Measure of the sorption
phenomenon, whereby a chemical
is divided between the soil and
water phase; also referred to as
adsorption partition
coefficient. |
|
Pathogenic |
Capable of causing disease.
|
|
Pathogens |
Microorganisms that can cause
disease in other organisms or in
humans, animals and plants
(e.g., bacteria, viruses, or
parasites) found in sewage, in
runoff from farms or rural areas
populated with domestic and wild
animals, and in water used for
swimming. Fish and shellfish
contaminated by pathogens, or
the contaminated water itself,
can cause serious illness. |
|
Pentachlorophenol (PCP)
|
Dark-colored flakes and
needle-like crystals which have
a pungent odor when hot. It is
used in wood preservatives, wood
products, starches, dextrins,
glue and algae control in
herbicide formulation. PCP
causes a variety of systemic
problems that can lead to death.
It is a Group B2, probable human
carcinogen. |
|
Percent Saturation |
The
amount of a substance that is
dissolved in a solution compared
to the amount that could be
dissolved in it. |
|
Percent Solids |
The
proportion of solid in a soil
sample determined by drying an
aliquot of the sample. |
|
Perched Aquifer |
1)
Unconfined groundwater separated
from an underlying main body of
groundwater by a localized
unsaturated zone. 2) Zone of
unpressurized water held above
the water table by a small lens
of impermeable rock or sediment.
|
|
Perchloroethylene (PCE)
|
A
volatile, clear, colorless
liquid with an ethereal odor.
Its former uses included dry
cleaning, degreasing metals, and
as a solvent. Contact can cause
dermatitis and irritation,
ingestion can cause
gastrointestinal irritation.
Exposures can result in acute or
fatal toxicity. Synonyms -
Tetrachloroethene, and
Tetrachloroethylene. |
|
Percolating Water |
Water that passes through rocks
or soil under the force of
gravity. |
|
Percolation |
1)
Movement under hydrostatic
pressure of water, through the
interstices of rocks or soils,
downward to groundwater, except
movement through large openings
such as solution channels. 2)
Slow seepage of water through a
filter. |
|
Performance Evaluation (PE)
Sample |
Contains unknown quantities of
analytes sent to a laboratory
for analysis as part of the lab
evaluation. |
|
Performance Standards |
1)
Regulatory requirements limiting
the concentrations of designated
organic compounds, particulate
matter, and hydrogen chloride in
emissions from incinerators. 2)
Operating standards established
by EPA for various permitted
pollution control systems,
asbestos inspections, and
various program operations and
maintenance requirements. |
|
Permeability |
1)
The property or capacity of a
porous rock, sediment or soil to
transmit a fluid per unit cross
section without damage to the
structure of the media. 2) A
measure of the ease of fluid
flow under unequal pressure. 3)
A measure of how interconnected
the pores of a material are.
|
|
Permissible Dose |
The
dose of a chemical that may be
received by an individual
without the expectation of a
significantly harmful result.
|
|
Permissible Exposure Limit (PEL)
|
The
maximum permissible
concentration of a toxic
chemical or exposure level of a
harmful physical agent (normally
averaged over an 8-hour period)
to which a person may be
exposed. |
|
Permit |
An
authorization, license, or
equivalent control document
issued by EPA or an approved
state agency to implement the
requirements of an environmental
regulation; e.g., a permit to
operate a wastewater treatment
plant or to operate a facility
that may generate harmful
emissions. |
|
Persistence |
Refers to the length of time a
compound stays in the
environment, once introduced. A
compound may persist for less
than a second or indefinitely.
|
|
Personal Protective Equipment
(PPE) |
Any
material or device worn to
protect a worker from exposure
to or contact with any harmful
substance or force. For IR
Program work, it includes
protective clothing, respiratory
devices, and protective shields
and barriers. |
|
Pesticide |
Substances or mixtures intended
for preventing, destroying,
repelling, or mitigating any
pest. Also, any substance or
mixture intended for use as a
plant regulator, defoliant, or
desiccant. |
|
Petroleum |
Including crude oil or any
fraction thereof that is liquid
at standard conditions of
temperature and pressure (60° F
and 14.7 lb/in2
absolute; 15.5C° and 10335.6
kg/m2). The term
includes petroleum-based
substances comprised of a
complex blend of hydrocarbons
derived from crude oil through
processes of separation,
conversion, upgrading, and
finishing, such as motor fuels,
jet oils, lubricants, petroleum
solvents, and used oils. |
|
Petroleum Derivatives |
Chemicals formed when petroleum
products break down in contact
with groundwater. |
|
Petroleum, Oil and Lubricants
(POL) |
For
example jet fuel, gasoline,
diesel fuel and POL sludges.
|
|
pH |
The
negative value of the power to
which 10 is raised in order to
obtain the concentration of
hydrogen ions (H3O+)
in gram-equivalents per liter.
pH is a measure of the acidity
or basicity of a material:
measured 0 through 14 with 7
being neutral, 0 being highly
acidic and 14 being highly
basic. Natural waters usually
have a pH between 6.5 and 8.5.
|
|
Phenolphthalein Alkalinity
|
The
alkalinity in a water sample
measured by the amount of
standard acid needed to lower
the pH to a level of 8.3 as
indicated by the change of color
of the phenolphthalein from pink
to clear. |
|
Phenols |
Organic compounds that are
byproducts of petroleum
refining, tanning, and textile,
dye, and resin manufacturing.
Low concentrations cause taste
and odor problems in water;
higher concentrations can kill
aquatic life and humans. |
|
Phosphates |
Certain chemical compounds
containing phosphorus.
|
|
Phosphorus (P) |
An
essential chemical food element
that can contribute to nutrient
loading of lakes and other water
bodies. Increased phosphorus
levels result from discharge of
phosphorus-containing materials
into surface waters, like
fertilizers. |
|
Photosynthesis |
The
manufacture by plants of
carbohydrates and oxygen from
carbon dioxide mediated by
chlorophyll in the presence of
sunlight.
|
|
Physical and Chemical Treatment
|
Processes generally used in
large-scale wastewater treatment
facilities. Physical processes
may include air-stripping or
filtration. Chemical treatment
includes coagulation,
chlorination, or ozonation. The
term can also refer to treatment
of toxic materials in surface
and groundwaters, oil spills,
and some methods of dealing with
hazardous materials on or in the
ground. |
|
Phytoplankton |
That portion of the plankton
community comprised of tiny
plants, e.g., algae, diatoms.
|
|
Phytoremediation |
A
remediation technology using
plants to degrade contaminants
in soil, sediment and
groundwater. |
|
Phytotoxic |
Harmful to plants. |
|
Picoplankton |
Plankton in the size range of
0.2 to 2.0 ðmm.
|
|
Piezometer |
A
well with a screen length that
is only 1-5% of an aquifer’s
saturated thickness. Generally
used to measure the total
potential or head at a point in
an aquifer. |
|
Piezometric Surface |
An
imaginary surface that
everywhere coincides with the
static water level in a confined
aquifer. |
|
Pilot Tests |
Testing a cleanup technology
under actual site conditions to
identify potential problems
prior to full-scale
implementation.
|
|
Pipe Schedule |
Standard method for designating
the wall thickness of pipe.
|
|
Plankton |
Tiny plants and animals that
live in water.
|
|
Plasma-Arc Reactor |
An
incinerator that operates at
extremely high temperatures and
treats highly toxic wastes that
do not burn easily. |
|
Plastics |
Non-metallic chemoreactive
compounds molded into rigid or
pliable construction materials,
fabrics, etc. |
|
Plugging |
Act
or process of stopping the flow
of water, oil, or gas into or
out of a formation through a
borehole or well penetrating
that formation. |
|
Plume |
1)
A visible or measurable
discharge of a contaminant from
a given point of origin. Can be
visible or thermal in water as
it extends downstream from the
pollution source, or visible in
air as, for example, a plume of
smoke. 2) The area of radiation
leaking from a damaged reactor.
3) Area downwind within which a
release could be dangerous for
those exposed to leaking fumes.
|
|
Plutonium (Pu) |
A
radioactive metallic element
chemically similar to uranium.
|
|
pOH |
The
negative value of the power to
which 10 is raised in order to
obtain the concentration of
hydroxide ions (OH-)
in gram-equivalents per liter.
Effectively, pOH is the opposite
of pH: 7 is neutral, 0 is highly
basic and 14 is highly acidic.
|
|
Point(s) of Compliance |
A
location(s) selected between the
source area(s) and the potential
point(s) of exposure where
concentrations of chemicals of
concern must be at or below the
determined target levels in
media (for example, groundwater,
soil, or air). |
|
Point(s) of Exposure |
The
point(s) at which an individual
or population may come in
contact with a chemical(s) of
concern originating from a site.
|
|
Point Source |
1)
A stationary location or fixed
facility from which pollutants
are discharged. 2) Any single
identifiable source of
pollution, e.g., a pipe, ditch,
ship, ore pit, factory
smokestack, etc. |
|
Polar |
Describing a substance or
molecule in which the positive
and negative electrical charges
are permanently separated, as
opposed to nonpolar molecules in
which the charges coincide.
Polar molecules ionize in
solution and impart electrical
conductivity. Water, alcohol,
and sulfuric acid are polar.
Most hydrocarbon liquids are
nonpolar. Carboxyl and hydroxyl
groups often exhibit an electric
charge. The formation of
emulsions and the action of
detergents are dependent on this
behavior. |
|
Pollen |
1)
The fertilizing element of
flowering plants. 2) Background
air pollutant. |
|
Pollutant |
1)
As defined by section 101(33) of
CERCLA, shall include but not be
limited to, any element,
substance, compound or mixture,
including disease-causing
agents, which after release into
the environment and upon
exposure, ingestion, inhalation,
or assimilation into any
organism, either directly from
the environment or indirectly by
ingestion through food chains,
will or may reasonably be
anticipated to cause death,
disease, behavioral
abnormalities, cancer, genetic
mutation, physiological
malfunctions (including
malfunctions in reproduction) or
physical deformations, in such
organisms or their offspring.
Shall not include petroleum,
including crude oil or any
fraction thereof which is not
otherwise specifically listed or
designated as a hazardous
substance and shall not include
natural gas, liquified natural
gas or synthetic gas of pipeline
quality (or mixtures of natural
gas and such synthetic gas). 2)
For purposes of the NCP, the
term pollutant or contaminant
means any pollutant or
contaminant that may present an
imminent and substantial danger
to public health or welfare. 3)
Generally, any substance
introduced into the environment
that adversely affects the
usefulness of a resource. |
|
Pollution |
Generally, the presence of
matter or energy whose nature,
location, or quantity produces
undesired environmental effects.
Under the Clean Water Act, for
example, the term is defined as
the manmade or man-induced
alteration of the physical,
biological, chemical, and
radiological integrity of water.
|
|
Pollution Prevention (P2)
|
The
active process of identifying
areas, processes, and activities
which create excessive waste
byproducts for the purpose of
substitution, alteration, or
elimination of the process to
prevent waste generation. |
|
Polonium (Po) |
A
radioactive element that occurs
in pitchblende and other uranium
containing ores. |
|
Polychaete |
A
marine worm with paired,
flattened, bristle-tipped organs
of locomotion. |
|
Polychlorinated Biphenyl (PCB)
|
Chemical mixtures comprised of
many isomers and compounds which
vary from mobile, oily liquids
to white, crystalline solids and
hard, noncrystalline resins.
PCBs have excellent fire
retardant capabilities and
chemical stability resulting in
wide-spread use in electrical
equipment. PCBs were used in the
dielectric fluid of electrical
transformers and capacitors for
insulating purposes and in gas
pipeline systems as lubricant.
PCBs, however, are persistent
and especially toxic when
involved in fire-related
incidents. Further sale for new
use was banned by law in 1979.
PCBs cause lesions of the skin
and liver. Extensive damage to
the liver from exposure can lead
to death. The higher the
chlorine content of the
compound, the more toxic the
effects. PCBs are Group B2,
animal carcinogens. Common types
of PCBs are Aroclor 1248, 1254,
and 1260.
|
|
Polycyclic Aromatic Hydrocarbon
(PAH) |
Hydrocarbons with multiple
benzene rings. PAHs are typical
components of asphalt, fuel,
oils, and greases. Examples of
PAHs include naphthalene, the
benzo pyrenes, fluoranthene, and
chrysene. Synonym - Polynuclear
Aromatic Hydrocarbon. |
|
Polymer |
Basic molecular ingredients in
plastic. |
|
Polynuclear Aromatic Hydrocarbon
(PNA) |
Hydrocarbons with multiple
benzene rings. PNAs are typical
components of asphalt, fuel,
oils, and greases. Examples of
PNAs include naphthalene, the
benzo pyrenes, fluoranthene, and
chrysene. Synonym - Polycyclic
Aromatic Hydrocarbons. |
|
Polyvinyl Chloride (PVC)
|
A
tough, environmentally
indestructible plastic that
releases hydrochloric acid when
burned. |
|
Population |
1)
A group of interbreeding
organisms occupying a particular
space. 2) The number of humans
or other living creatures in a
designated area. |
|
Population at Risk |
A
population subgroup that is more
likely to be exposed to a
chemical, or is more sensitive
to the chemical, than is the
general population. |
|
Pore Space |
The
void space and minute passages
in a solid material. |
|
Porosity |
1)
Degree to which soil, gravel,
sediment or rock is permeated
with pores or cavities through
which water or air can move. 2)
The ratio of the volume of the
openings in a rock to the total
volume of the rock.
|
|
Post-Closure |
The
time period following the
shutdown of a waste management
or manufacturing facility; for
monitoring purposes, often
considered to be 30 years. |
|
Potable Water |
Water that is safe for drinking
and cooking.
|
|
Potassium (K) |
An
alkali metal that forms various
salts with halogens and other
metals. It is an essential
nutrient, and among other uses,
it is used in electrical
impulses in the nervous system.
It is abundant naturally, and is
generally not considered toxic.
|
|
Potential Receptor |
Any
living organism or environmental
medium which is in the pathway
of contamination from a
discharge. |
|
Potentially Responsible Party
(PRP) |
Any
individual or company, including
owners, operators, transporters
or generators, potentially
responsible for, or contributing
to a spill or other
contamination at a Superfund
site. Whenever possible, through
administrative and legal
actions, GPA requires PRPs to
clean up hazardous sites they
have contaminated. |
|
Potentially Responsible Party
(PRP) Site |
Sites where the DOD has no
current or past ownership
interest and where DOD has a
responsibility for cleanup of
the site under CERCLA. |
|
Potentiation |
The
effect of one chemical to
increase the effect of another
chemical. |
|
Potentiometric Surface |
1)
An imaginary surface that
everywhere coincides with the
static water level in a confined
aquifer. 2) The level to which
water will rise in cased wells
or other cased excavations into
confined aquifers.
|
|
Practical Quantitation Limits
(PQL) |
The
minimum concentration of an
analyte required to be measured
and allowed to be reported
without qualification as an
estimated quantity for samples
without substantial
interferences (for technical
representation see SW-846).
|
|
Precipitate |
A
solid that separates from a
solution. |
|
Precipitation |
1)
The formation of solids out of
constituents that were once
dissolved. Precipitation is
caused by a change in
conditions, such as temperature,
chemical concentration, or the
presence of seed particles to
begin the process. 2) Water
droplets or ice particles, as
rain or snow, condensed from
atmospheric water vapor and
massive enough to fall to the
earth’s surface. 3) Removal of
hazardous solids from liquid
waste to permit safe disposal.
4) Removal of particles from
airborne emissions. |
|
Precision |
A
measure of mutual agreement
among individual measurements of
the same property, usually under
prescribed similar conditions.
Precision is usually expressed
in terms of standard deviation.
|
|
Preliminary Assessment (PA)
|
Identifies potential areas of
contamination for further
investigation. Consists of a
review of available historical
information (also known as a
records search), aerial
photographs, employee
interviews, and site visits to
gain information concerning
installation activities and land
use.
|
|
Preliminary Natural Resource
Survey (PNRS) |
A
simple screening study of a site
by a trustee to determine
whether trustee resources may
have been affected and whether
further attention is warranted.
|
|
Preliminary Remediation Goals
(PRGs) |
Concentration levels set for
individual chemicals that, for
carcinogens corresponds to a
specific cancer risk level of 1
in 1 million and for
noncarcinogens corresponds to a
Hazard Quotient of 1. PRGs are
generally selected when ARARs
are not available. |
|
Pretreatment |
Processes used to reduce,
eliminate, or alter the nature
of wastewater pollutants from
non-domestic sources before they
are discharged into publicly
owned treatment works (POTWs).
|
|
Prevention |
Measures taken to minimize the
release of wastes to the
environment. |
|
Primary Drinking Water
Regulation |
Applies to public water systems
and specifies a contaminant
level, which, in the judgment of
the EPA Administrator, will not
adversely affect human health.
|
|
Primary Substrate |
Substrate which provides the
majority of the growth and
energy requirements for cells.
|
|
Priority Pollutant |
A
group of approximately 130
chemicals (about 110 are
organics) that appear on a USEPA
list because they are toxic and
relatively common in industrial
discharges. |
|
Probability of Detection
|
The
likelihood, expressed as a
percentage, that a test method
will correctly identify a
leaking tank. |
|
Production Well |
A
well of sufficient production so
it can be used for public use,
either as a water supply, or for
industrial purposes. |
|
Proposed Plan |
A
plan for a site cleanup that is
available to the public for
comment. |
|
Proteins |
Complex nitrogenous organic
compounds of high molecular
weight made of amino acids;
essential for growth and repair
of animal tissue. Many, but not
all, proteins are enzymes. |
|
Protocol |
A
series of formal steps for
conducting a test.
|
|
Protozoa |
One-celled animals that are
larger and more complex than
bacteria. May cause disease.
|
|
Public |
As
defined by the NCP includes
citizens directly affected by a
site, other interested citizens
or parties, organized groups,
elected officials, and
potentially responsible parties.
|
|
Public Hearing |
A
formal meeting wherein officials
hear the public's views and
concerns about an action or
proposal. The Navy is required
to consider such comments when
evaluating its actions. Public
hearings must be held upon
request during the public
comment period. |
|
Public Notice |
1)
Notification by EPA informing
the public of Agency actions
such as the issuance of a draft
permit or scheduling of a
hearing. EPA is required to
ensure proper public notice,
including publication in
newspapers and broadcast over
radio stations. 2) In the safe
drinking water program, water
suppliers are required to
publish and broadcast notices
when pollution problems are
discovered. |
|
Public Water Supply |
In
Virginia, as defined by the
Virginia Department of Health, a
water system serving at least 25
individuals or more than 15
residential connections. |
|
Publicly Owned Treatment Works
(POTW) |
A
waste-treatment works owned by a
state, unit of local government,
or Indian tribe, usually
designed to treat domestic
wastewaters. |
|
Pump and Treat Technology
|
Treatment method in which
contaminated water is pumped out
of the ground and then treated
before being discharged. |
|
Pumping Level |
Depth to water in a well when
the well is being pumped. |
|
Pumping Test |
Pumping of a well at a constant
rate in order to obtain
information about the
performance of the well or to
provide data from which the
principal factors of aquifer
performance can be calculated. A
test for the latter purpose is
also called an aquifer test.
|
|
Pyrolysis |
Decomposition of a chemical by
extreme heat.
|
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|
Q
|
|
|
Qualified Individual (QI)
|
A
term used by the U. S. Coast
Guard for the designated
individual who is trained in oil
and hazardous substance facility
response and acts as liaison
with the Federal OSC in spill
response activities.
|
|
Qualitative |
Analysis without regard to
quantity or specific numeric
values. |
|
Qualitative Risk Analysis
|
A
nonnumeric evaluation of a site
to determine potential exposure
pathways and receptors based on
known or readily available
information. |
|
Quality Assurance (QA) |
The
total integrated program put in
place to assure the reliability
of data generated in the
laboratory. |
|
Quality Assurance Project Plan
(QAPP) |
A
written document associated with
all remedial site sampling
activities, which presents in
specific terms the organization
(where applicable), objectives,
functional activities, and
specific Quality Assurance (QA)
and Quality Control (QC)
activities designed to achieve
the Data Quality Objectives
(DQO) of a specific project(s)
or continuing operation(s). The
QAPP is prepared for each
specific project or continuing
operation (or group of similar
projects or continuing
operations). The QAPP will be
prepared by the responsible
program office, regional office,
laboratory, contractor,
recipient of an assistance
agreement, or other
organization. For an enforcement
action, potentially responsible
parties may prepare a QAPP
subject to lead agency approval.
There are 16 essential elements
which EPA has mandated to be
addressed in a project plan.
|
|
Quality Assurance/Quality
Control (QA/QC) |
A
system of procedures, checks,
audits, and corrective actions
to ensure that all research
design and performance,
environmental monitoring and
sampling, and other technical
and reporting activities are of
the highest achievable quality.
|
|
Quality Control (QC) |
The
routine application of specific,
well-defined procedures which
ensure the generation of data
which fulfill the objectives of
the QA program. |
|
Quantitative |
Analysis with regard to
quantities or specific numeric
values. |
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R
|
|
|
Radius of Influence |
The
maximum distance from the
extraction or injection well
where vacuum or pressure (soil
gas or groundwater movement)
occurs. |
|
Radius of Oxygen Influence
|
The
radius to which oxygen has to be
supplied to sustain maximal
biodegradation; a function of
both air flowrates and oxygen
utilization rates, and therefore
depends on site geology, well
design, and microbial activity.
|
|
Radius of Vulnerability Zone
|
The
maximum distance from the point
of release of a hazardous
substance in which the airborne
concentration could reach the
level of concern under specified
weather conditions. |
|
Radon (Rn) |
A
colorless, naturally occurring,
radioactive, inert gas formed by
radioactive decay of radium
atoms in soil or rocks. |
|
Raoult's Law |
A
physical-chemical law which
states that the vapor pressure
of a solution is equal to the
mole fraction of the solvent
multiplied by the vapor pressure
of the pure solvent. |
|
Raw Sewage |
Untreated wastewater and its
contents. |
|
Raw Water |
Intake water prior to any
treatment or use.
|
|
RCRA Facility Assessment (RFA)
|
The
initial process to determine
whether corrective action at a
site is warranted or to define
what additional data must be
gathered to make this
determination. Equivalent to a
CERCLA Preliminary Assessment
(PA). RFAs are performed as part
of the RCRA permitting process.
|
|
RCRA Facility Investigation
(RFI) |
The
process of determining the
extent of hazardous waste
contamination. Equivalent to the
CERCLA Remedial Investigation
(RI).
|
|
RCRA Part A Permit |
Identifies treatment, storage
and disposal units within a
to-be-permitted facility. |
|
RCRA Part B Permit |
Describes the wastes managed,
the quantities, and the
facilities. Allows the
management of a treatment,
storage, and disposal facility.
|
|
Reactivity |
The
ability of a material to undergo
a chemical reaction with the
release of energy. It could be
initiated by mixing or reacting
with other materials,
application of heat, physical
shock, etc. |
|
Reagent Blank |
Usually an organic aqueous
solution that is as free of
analyte as possible and contains
all the reagents in the same
volume as used in the processing
of samples. The reagent blank
must be carried through the
complete sample preparation
procedure and contains the same
reagent concentrations in the
final solution as in the sample
solution used for analysis. The
reagent blank is used to correct
for possible contamination
resulting from the preparation
or processing of the sample. One
reagent blank should be prepared
for every analytical batch or
for every 20 samples, whichever
is more frequent. |
|
Reasonable Maximum Exposure
(RME) |
The
maximum exposure reasonably
expected to occur at a site. The
RME is estimated for both the
current and future land-use
conditions. For Superfund
exposure assessments, intake
values for a given pathway
should be selected so that the
combination of all intake
variables results in an estimate
of the reasonable maximum
exposure for that pathway.
|
|
Reasonable Potential Exposure
Scenario |
A
situation with a credible chance
of occurrence where a receptor
may become directly or
indirectly exposed to the
chemical(s) of concern without
considering extreme or
essentially impossible
circumstances.
|
|
Reasonably Anticipated Future
Use |
Future use of a site or facility
that can be predicted with a
high degree of certainty given
current use, local government
planning, and zoning. |
|
Reasonably Available Control
Technology (RACT) |
Control technology that is
reasonably available, and both
technologically and economically
feasible. Usually applied to
existing sources in
nonattainment areas; in most
cases is less stringent than new
source performance standards.
|
|
Reasonably Available Control
Measures (RACM) |
A
broadly defined term referring
to technological and other
measures for pollution control.
|
|
Recarbonization |
Process in which carbon dioxide
is bubbled into water being
treated to lower the pH. |
|
Receiving Waters |
A
river, lake, ocean, stream or
other watercourse into which
wastewater or treated effluent
is discharged. |
|
Receptor |
Any
living organism or environmental
medium which is exposed to
contamination from a discharge.
|
|
Receptor Factor (RF) |
An
indication of the potential for
human or ecological contact with
site contaminants. |
|
Recharge |
The
addition of water to an aquifer
by natural infiltration or
artificial means. Injection of
water into an aquifer through
wells is one form or artificial
recharge. |
|
Recharge Area |
A
land area in which water reaches
the zone of saturation from
surface infiltration, e.g.,
where rainwater soaks through
the earth to reach an aquifer.
|
|
Recharge Rate |
The
quantity of water per unit of
time that replenishes or refills
an aquifer. |
|
Reclamation |
(In
recycling) Restoration of
materials found in the waste
stream to a beneficial use which
may be for purposes other than
the original use. |
|
Recommended Maximum Contaminant
Level (RMCL) |
The
maximum level of a contaminant
in drinking water at which no
known or anticipated adverse
affect on human health would
occur, and that includes an
adequate margin of safety.
Recommended levels are
nonenforceable health goals. See
Maximum Contaminant Level. |
|
Record |
All
books, papers, maps, aerial
photographs, architectural or
engineering drawings,
photographs, machine readable
materials, or other documentary
materials regardless of physical
form or characteristics made or
received by an agency of the
United States Government under
Federal law or in conjunction
with the transaction of public
business and preserved or
appropriate for preservation by
that agency or its legitimate
successor as evidence of the
organization, functions,
policies, decisions, procedures,
operations, or other activities
of the Government. |
|
Record of Decision (ROD)
|
1)
A public document that explains
the remedy selection process and
which cleanup alternative(s)
will be used at National
Priorities List sites where,
under CERCLA, Trust Funds pay
for the cleanup. 2) The official
term used by CERCLA and the NCP
for the documentation of a final
remedial response action
| | | | | | | | |