Glossary

AA

See atomic absorption spectrometry.

absorption

The process by which the number and energy of particles or photons entering a body of matter is reduced by interaction with the matter.

accuracy

The closeness of the result of a measurement to the true value of the quantity.

aliquot

The quantity of sample being used for analysis.

alkalinity

Alkalinity is a measure of the buffering capacity of water, and because pH has a direct effect on organisms as well as an indirect effect on the toxicity of certain other pollutants in the water, the buffering capacity is important to water quality.

alpha particle

A positively charged particle emitted from the nucleus of an atom having the same charge and mass as that of a helium nucleus (two protons and two neutrons).

ambient air

The surrounding atmosphere as it exists around people, plants, and structures.

analytical detection limit

The lowest reasonably accurate concentration of an analyte that can be detected; this value varies depending on the method, instrument, and dilution used.

analyte

A constituent or parameter that is being analyzed.

anion

A negatively charged ion.

aquifer

A saturated, permeable geologic unit that can transmit significant quantities of water under ordinary hydraulic gradients.

aquitard

A geologic unit that inhibits the flow of water.

ash

Inorganic residue remaining after ignition of combustible substances.

assimilate

To take up or absorb into the body.

atom

Smallest particle of an element capable of entering into a chemical reaction.

atomic absorption spectrometry (AA)

Chemical analysis performed by vaporizing a sample and measuring the absorbance of light by the vapor.

Atomic Energy Commission (AEC)

A federal agency created in 1946 to manage the development, use, and control of nuclear energy for military and civilian application. It was abolished by the Energy Reorganization Act of 1974 and succeeded by the Energy Research and Development Administration (now part of the U.S. Department of Energy and the U.S. Nuclear Regulatory Commission).

base/neutral and acid extractables (BNA)

A group of organic compounds analyzed as part of Appendix IX of 40 CFR 264 and the EPA list of priority pollutants.

beta particle

A negatively charged particle emitted from the nucleus of an atom. It has a mass and charge equal to those of an electron.

biomass

The weight of any specific or general kind of organic matter, usually expressed per area or volume.

biota

The animal and plant life of a particular region considered as a total ecological entity.

blank

A control sample that is identical, in principle, to the sample of interest, except that the substance being analyzed is absent. In such cases, the measured value or signal for the substance being analyzed is believed to be a result of artifacts. Under certain circumstances, that value may be subtracted from the measured value to give a net result reflecting the amount of the substance in the sample. EPA does not permit the subtraction of blank results in EPA-regulated analyses.

calibration

Determination of variance from a standard of accuracy of a measuring instrument to ascertain necessary correction factors.

carcinogen

A cancer-causing substance.

cation

Positively charged ion.

CERCLA-reportable release

A release to the environment that exceeds reportable quantities as defined by CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act).

chain-of-custody

A form that documents sample collection, transport, analysis, and disposal.

chemical oxygen demand

Indicates the quantity of oxidizable materials present in a water and varies with water composition, concentrations of reagent, temperature, period of contact, and other factors.

chlorocarbons

Compounds of carbon and chlorine, or carbon, hydrogen, and chlorine, such as carbon tetrachloride, chloroform, tetrachloroethylene, etc. They are among the most significant and widespread environmental contaminants. Classified as hazardous wastes, chlorocarbons may have a tendency to cause detrimental effects, such as birth defects.

closure

Control of a hazardous waste management facility under RCRA requirements.

compliance

Fulfillment of applicable requirements of a plan or schedule ordered or approved by government authority.

concentration

The amount of a substance contained in a unit volume or mass of a sample.

conductivity

A measure of water's capacity to convey an electric current. This property is related to the total concentration of the ionized substances in water and the temperature at which the measurement is made.

confluence

The point at which two or more streams meet; the point where a tributary joins the main stream.

contamination

Deposition of unwanted material on the surfaces of structures, areas, objects, or personnel.

cosmic radiation

Ionizing radiation with very high energies, originating outside the earth's atmosphere. Cosmic radiation is one source contributing to natural background radiation.

count

The signal that announces an ionization event within a counter; a measure of the radiation from an object or device.

curie (Ci)

A unit of radioactivity. One curie is defined as 3.7 x 10¹⁰ (37 billion) disintegrations per second. Several fractions and multiples of the curie are commonly used:

kilocurie (kCi): 10³ Ci, one thousand curies; 3.7 x 10¹³ disintegrations per second.
millicurie (mCi): 10^-3 Ci, one-thousandth of a curie; 3.7 x 10⁷ disintegrations per second.
microcurie ( Ci): 10^-6 Ci, one-millionth of a curie; 3.7 x 10⁴ disintegrations per second.
picocurie (pCi): 10 ^-12 Ci, one-trillionth of a curie; 0.037 disintegrations per second.

daughter

A nuclide formed by the radioactive decay of a parent nuclide.

decay, radioactive

The spontaneous transformation of one radionuclide into a different radioactive or nonradioactive nuclide, or into a different energy state of the same radionuclide.

dense nonaqueous phase liquid (DNAPL)

The liquid phase of chlorinated organic solvents. These liquids are denser than water and include commonly used industrial compounds such as tetrachloroethylene and trichloroethylene.

derived concentration guide (DCG)

The concentration of a radionuclide in air or water that, under conditions of continuous exposure for one year by one exposure mode (i.e., ingestion of water, submersion in air or inhalation), would result in either an effective dose equivalent of 0.1 rem (1 mSv) or a dose equivalent of 5 rem (50 mSv) to any tissue, including skin and lens of the eye. The guides for radionuclides in air and water are given in DOE Order 5400.5.

desorption

The process of removing a sorbed substance by the reverse of adsorption or absorption.

dilution factor

The mathematical factor by which a sample is diluted to bring the concentration of an analyte in a sample within the analytical range of a detector (e.g., 1 mL sample + 9 mL solvent = 1:10 dilution, or a dilution factor of 10).

disintegration, nuclear

A spontaneous nuclear transformation (radioactivity) characterized by the emission of energy and/or mass from the nucleus of an atom.

dissolved oxygen

A desirable indicator of satisfactory water quality in terms of low residuals of biologically available organic materials. Dissolved oxygen prevents the chemical reduction and subsequent leaching of iron and manganese from sediments.

dose

The energy imparted to matter by ionizing radiation. The unit of absorbed dose is the rad, equal to 0.01 joules per kilogram in any medium.

absorbed dose: The quantity of radiation energy absorbed by an organ, divided bythe organ's mass. Absorbed dose is expressed in units of rad (or gray) (1 rad = 0.01 Gy).
dose equivalent: The product of the absorbed dose (rad) in tissue and a quality factor. Dose equivalent is expressed in units of rem (or sievert) (1 rem = 0.01 sievert).
committed dose equivalent: The calculated total dose equivalent to a tissue or organ over a 50-year period after known intake of a radionuclide into the body. Contributions from external dose are not included. Committed dose equivalent is expressed in units of rem (or sievert).
committed effective dose equivalent: The sum of the committed dose equivalents to various tissues in the body, each multiplied by the appropriate weighting factor. Committed effective dose equivalent is expressed in units of rem (or sievert).
effective dose equivalent: The sum of the dose equivalents received by all organs or tissues of the body after each one has been multiplied by an appropriate weighting factor. The effective dose equivalent includes the committed effective dose equivalentfrom internal deposition of radionuclides and the effective dose equivalent attributable to sources external to the body.
collective dose equivalent/collective effective dose equivalent: The sums of the dose equivalents or effective dose equivalents of all individuals in an exposed populationwithin a 50-mile (80-km) radius, and expressed in units of person-rem (or person-sievert). When the collective dose equivalent of interest is for a specific organ, the units would be organ-rem (or organ-sievert). The 50-mile distance is measured from a point located centrally with respect to major facilities or DOE program activities.

dosimeter

A portable detection device for measuring the total accumulated exposure to ionizing radiation.

dosimetry

The theory and application of principles and techniques involved in the measurement and recording of radiation doses. Its practical aspect is concerned with using various types of radiation instruments to make measurements.

downgradient

In the direction of decreasing hydrostatic head.

downgradient well

A well that is installed hydraulically downgradient of a site and may be capable of detecting migration of contaminants from a site.

drinking water standards (DWS)

Federal primary drinking water standards, both proposed and final, as set forth by EPA.

duplicate samples

Two or more samples collected simultaneously into separate containers.

duplicate result

A result derived by taking a portion of a primary sample and performing the identical analysis on that portion as is performed on the primary sample.

effluent

A liquid or gaseous waste discharge to the environment.

effluent monitoring

The collection and analysis of samples or measurements of liquid and gaseous effluents for purposes of characterizing and quantifying the release of contaminants, assessing radiation exposures of members of the public, and demonstrating compliance with applicable standards.

Environmental Restoration

A DOE program that directs the assessment and cleanup of its sites (remediation) and facilities contaminated with waste as a result of nuclear-related activities.

exposure (radiation)

The incidence of radiation on living or inanimate material by accident or intent. Background exposure is the exposure to natural background ionizing radiation. Occupational exposure is that exposure to ionizing radiation that takes place during a person's working hours. Population exposure is the exposure to the total number of persons who inhabit an area.

external radiation

Exposure to ionizing radiation when the radiation source is located outside the body.

fecal coliform

The coliform group comprises all of the aerobic, non-spore-forming, rod-shaped bacteria. The test determines the presence or absence of coliform organisms.

formation

A mappable unit of consolidated or unconsolidated geologic material of a characteristic lithology or assemblage of lithologies.

friable asbestos

Asbestos that is brittle or readily crumbled.

gamma ray

High-energy, short-wavelength electromagnetic radiation emitted from the nucleus of an excited atom. Gamma rays are identical to X rays except for the source of the emission.

gamma spectrometry

A system consisting of a detector, associated electronics, and a multichannel analyzer that is used to analyze samples for gamma-emitting radionuclides.

genotoxicology

The study of the effects of chemicals or radioactive contaminants on the genetics of individual animals or plants.

grab sample

A sample collected instantaneously with a glass or plastic bottle placed below the water surface to collect surface water samples (also called dip samples).

groundwater, unconfined

Groundwater exposed to the unsaturated zone.

half-life, biological

The time required for a biological system, such as that of a human, to eliminate by natural processes half the amount of a substance (such as a radioactive material) that has entered it.

half-life, radiological

The time required for half of a given number of atoms of a specific radionuclide to decay. Each nuclide has a unique half-life.

halogenated compound

An organic compound bonded with one of the five halogen elements (astatine, bromine, chlorine, fluorine, and iodine).

halomethane

Any compound that includes a methane group (CH3) bonded to a halogen element (astatine, bromine, chlorine, fluorine, or iodine).

hardness

Water hardness is caused by polyvalent metallic ions dissolved in water. In fresh water, these are mainly calcium and magnesium, although other metals such as iron, strontium, and manganese may contribute to hardness.

heavy water

Water in which the molecules contain oxygen and deuterium, an isotope of hydrogen that is heavier than ordinary hydrogen.

herbaceous

Having little or no woody tissue.

hydrology

The science dealing with the properties, distribution, and circulation of natural water systems.

hydrogeology

Hydrolic aspects of site geology.

in situ

In its original place; field measurements taken without removing the sample from its origin; remediation performed while groundwater remains below the surface.

internal dose factor

A factor used to convert intakes of radionuclides to dose equivalents.

internal radiation

Internal radiation occurs when natural radionuclides enter the body by ingestion of foods, milk, and water, and by inhalation. Radon is the major contributor to the annual dose equivalent for internal radionuclides.

ion

An atom or compound that carries an electrical charge.

ion exchange

Process in which a solution containing soluble ions is passed over a solid ion exchange column that removes the soluble ions by exchanging them with labile ions from the surface of the column. The process is reversible so that the trapped ions are removed (eluted) from the column and the column is regenerated.

irradiation

Exposure to radiation.

isotopes

Forms of an element having the same number of protons in their nuclei but differing in the number of neutrons.

long-lived isotope: A radionuclide that decays at such a slow rate that a quantityof it will exist for an extended period (half-life is greater than 3 years).
short-lived isotope: A radionuclide that decays so rapidly that a given quantity is transformed almost completely into decay products within a short period (half-life is 2 days or less).

lower limit of detection (LLD)

The smallest concentration/amount of analyte that can be reliably detected in a sample at a 95% confidence level.

maximally exposed individual

A hypothetical individual who remains in an uncontrolled area and would, when all potential routes of exposure from a facility's operations are considered, receive the greatest possible dose equivalent.

mercury

A silver-white, liquid metal solidifying at 38.9�C to form a tin-white, ductile, malleable mass. It is widely distributed in the environment and biologically is a nonessential or nonbeneficial element. Human poisoning from this highly toxic element has been clinically recognized.

microbes

Microscopic organisms.

migration

The transfer or movement of a material through the air, soil, or groundwater.

millirem (rem)

The dose equivalent that is one one-thousandth of a rem.

milliroentgen (mR)

A measure of X-ray or gamma radiation. The unit is one-thousandth of a roentgen.

minimum detectable activity

The smallest activity of a radionuclide that can be distinguished in a sample by a given measurement system at a preselected counting time and at a given confidence level.

monitoring

Process whereby the quantity and quality of factors that can affect the environment and/or human health are measured periodically in order to regulate and control potential impacts.

natural radiation

Radiation arising from cosmic and other naturally occurring radionuclide sources (such as radon) present in the environment.

nuclide

An atom specified by its atomic weight, atomic number, and energy state. A radionuclide is a radioactive nuclide.

outfall

The point of conveyance (e.g., drain or pipe) of wastewater or other effluents into a ditch, pond, or river.

parts per million (ppm)

A unit measure of concentration equivalent to the weight/volume ratio expressed as milligrams per liter.

parts per billion (ppb)

A unit measure of concentration equivalent to the weight/volume ratio expressed as grams per liter or nanograms per milliter.

person-rem

Collective dose to a population group. For example, a dose of 1 rem to 10 individuals results in a collective dose of 10 person-rem.

pH

A measure of the hydrogen ion concentration in an aqueous solution. Acidic solutions have a pH from 0 through 6, basic solutions have a pH >> 7, and neutral solutions have a pH = 7.

piezometer

An instrument used to measure the potentiometric surface of the groundwater. Also, a well designed for this purpose.

precision

The closeness of approach of a value of similar or replicate results to a common value in a series of measurements.

priority pollutants

A group of approximately 130 chemicals (about 110 are organics) that appear on a U.S. Environmental Protection Agency list because they are toxic and relatively common in industrial discharges.

process water

Water used within a system process.

process sewer

Pipe or drain, generally located underground, used to carry off process water and/or waste matter.

purge

To remove water prior to sampling, generally by pumping or bailing.

quality assurance (QA)

Any action in environmental monitoring to ensure the reliability of monitoring and measurement data.

quality control (QC)

The routine application of procedures within environmental monitoring to obtain the required standards of performance in monitoring and measurement processes.

quality factor

The factor by which the absorbed dose (rad) is multiplied to obtain a quantity that expresses, on a common scale for all ionizing radiation, the biological damage to exposed persons. It is used because some types of radiation, such as alpha particles, are more biologically damaging than others.

rad

The unit of absorbed dose deposited in a volume of material.

radioactivity

The spontaneous emission of radiation, generally alpha or beta particles or gamma rays, from the nucleus of an unstable isotope.

radioisotopes

Radioactive isotopes.

radionuclide

An unstable nuclide capable of spontaneous transformation into other nuclides by changing its nuclear configuration or energy level. This transformation is accompanied by the emission of photons or particles.

reclamation

Recovery of wasteland, desert, etc., by ditching, filling, draining, or planting.

reference material

A material or substance with one or more properties that is sufficiently well established and used to calibrate an apparatus, to assess a measurement method, or to assign values to materials.

regression analysis

A collection of statistical techniques that serve as a basis for drawing inferences about relationships among quantities in a scientific system.

release

Any discharge to the environment. Environment is broadly defined as any water, land, or ambient air.

rem

The unit of dose equivalent (absorbed dose in rads x the radiation quality factor). Dose equivalent is frequently reported in units of millirem (mrem) which is one-thousandth of a rem.

remediation

The correction of a problem. See Environmental Restoration.

RFI Program

RCRA Facility Investigation Program; EPA-regulated investigation of a solid waste management unit with regard to its potential impact on the environment.

RFI/RI Program

RCRA Facility Investigation/Remedial Investigation Program; On the ORR, the expansion of the RFI Program to include CERCLA and hazardous substance regulations.

roentgen

A unit of exposure from X or gamma rays. One roentgen equals 2.58 x 10 4 coulombs per kilogram of air.

screened interval

In well construction, the section of a formation that contains the screen, or perforated pipe, that allows water to enter the well.

seepage basin

An excavation that receives wastewater. Insoluble materials settle out on the floor of the basin, and soluble materials seep with the water through the soil column where they are removed partially by ion exchange with the soil. Construction may include dikes to prevent overflow or surface runoff.

self-absorption

Absorption of radiation by the sample itself, preventing detection by the counting instrument.

sensitivity

The capability of methodology or instruments to discriminate between samples with differing concentrations or containing varying amounts of analyte.

settleable solids

Material settling out of suspension within a defined period.

settling basin

A temporary holding basin (excavation) that receives wastewater, which is subsequently discharged.

sievert (Sv)

The SI (International System of Units) unit of dose equivalent, 1 Sv = 100 rem.

slurry

A suspension of solid particles (sludge) in water.

specific conductance

The ability of water to conduct electricity; this ability varies in proportion to the amount of ionized minerals in the water.

spike

The addition of a known amount of reference material containing the analyte of interest to a blank sample.

spiked sample

A sample to which a known amount of some substance has been added.

split sample

A sample that has been portioned into two or more containers from a single sample container or sample-mixing container.

stable

Not radioactive or not easily decomposed or otherwise modified chemically.

stack

A vertical pipe or flue designed to exhaust airborne gases and suspended particulate matter.

standard deviation

An indication of the dispersion of a set of results around their average.

standard reference material (SRM)

A reference material distributed and certified by the National Institute of Standards and Technology.

storm water runoff

Surface streams that appear after precipitation.

strata

Beds, layers, or zones of rocks.

substrate

The substance, base, surface, or medium in which an organism lives and grows.

surface water

All water on the surface of the earth, as distinguished from groundwater.

temperature

The thermal state of a body considered with its ability to communicate heat to other bodies.

terrestrial radiation

Ionizing radiation emitted from radioactive materials, primarily potassium-40, thorium, and uranium, in the earth's soils. Terrestrial radiation contributes to natural background radiation.

total activity

The total quantity of radioactive decay particles that are emitted from a sample.

total dissolved solids

Dissolved solids and total dissolved solids are terms generally associated with freshwater systems and consist of inorganic salts, small amounts of organic matter and dissolved materials.

total organic halogens

A measure of the total concentration of organic compounds that have one or more halogen atoms.

total solids

The sum of total dissolved solids and suspended solids.

total suspended particulates

Refers to the concentration of particulates in suspension in the air irrespective of the nature, source, or size of the particulates.

transect

A line across an area being studied. The line is composed of points where specific measurements or samples are taken.

transmissive zone

A zone of sediments sufficiently porous and permeable to allow the flow of groundwater through the zone.

transuranic waste

Solid radioactive waste containing primarily alpha-emitting elements heavier than uranium.

transuranium elements

Elements with higher atomic weights than uranium; all 13 known transuranic elements are radioactive and are produced artificially.

trip blank

A sample container of deionized water that is transported to the well sample location, treated as a well sample, and sent to the laboratory for analysis; trip blanks are used to check for contamination resulting from transport, shipping, and site conditions.

tritium (3H)

The hydrogen isotope with one proton and two neutrons in the nucleus. It emits a low-energy beta particle (0.0186 MeV maximum) and has a half-life of 12.5 years.

t-test

Statistical method used to determine if the means of groups of observations are equal.

turbidity

A measure of the concentration of sediment or suspended particles in solution.

unconsolidated zone

Soil zone located above the water table.

uncontrolled area

Any area to which access is not controlled for the purpose of protecting individuals from exposure to radiation and radioactive materials.

upgradient

In the direction of increasing hydrostatic head.

volatile organic compounds

Used in many industrial processes, the levels of these carcinogenic compounds must be kept to a minimum. They are measured by volatile organic analyses content. Common examples include trichloroethane, tetrachloroethylene, and trichloroethylene.

watershed

The region draining into a river, river system, or body of water.

wetlands

Lowland areas, such as a marshes or swamps, inundated or saturated by surface water or groundwater sufficiently to support hydrophytic vegetation typically adapted for life in saturated soils.

wind rose

A diagram in which statistical information concerning direction and speed of the wind at a location is summarized.