ASTM D1129-13(2020)e2

Standard Terminology Relating to Water

General Information

• Status: Published
• Publication Date: 30-Apr-2020
• ICS: 01.040.07 - Natural and applied sciences (Vocabularies)
• ICS: 07.060 - Geology. Meteorology. Hydrology
• Technical Committee: D19 - Water

Relations

• Replaces: ASTM D1129-13(2020)e1 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Referred By: ASTM D8070-23 - Standard Test Method for Screening of Fuels and Fuel Associated Aqueous Specimens for Microbial Contamination by Lateral Flow Immunoassay
• Effective Date: 01-May-2020
• Referred By: ASTM D2187-17 - Standard Test Methods and Practices for Evaluating Physical and Chemical Properties of Particulate Ion-Exchange Resins
• Effective Date: 01-May-2020
• Referred By: ASTM D4129-05(2020) - Standard Test Method for Total and Organic Carbon in Water by High Temperature Oxidation and by Coulometric Detection
• Effective Date: 01-May-2020
• Referred By: ASTM D5176-20 - Standard Test Method for Total Chemically Bound Nitrogen in Water by Pyrolysis and Chemiluminescence Detection
• Effective Date: 01-May-2020
• Referred By: ASTM E2914/E2914M-21 - Standard Practice for Ultrasonic Extraction of Lead from Composited Wipe Samples
• Effective Date: 01-May-2020
• Referred By: ASTM D6501-15 - Standard Test Method for Phosphonate in Brines
• Effective Date: 01-May-2020
• Referred By: ASTM D8273-20 - Standard Practice for Determination of Total and Available Cyanide in Solid Waste and Soil after Alkaline Extraction
• Effective Date: 01-May-2020
• Referred By: ASTM D5173-15(2023) - Standard Guide for On-Line Monitoring of Total Organic Carbon in Water by Oxidation and Detection of Resulting Carbon Dioxide
• Effective Date: 01-May-2020
• Referred By: ASTM F316-03(2019) - Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test
• Effective Date: 01-May-2020
• Referred By: ASTM D5246-19 - Standard Test Method for Isolation and Enumeration of <emph type="ital">Pseudomonas aeruginosa</emph> from Water
• Effective Date: 01-May-2020
• Referred By: ASTM D4107-20 - Standard Test Method for Tritium in Drinking Water
• Effective Date: 01-May-2020
• Referred By: ASTM D1066-18e1 - Standard Practice for Sampling Steam
• Effective Date: 01-May-2020
• Referred By: ASTM D4763-06(2020) - Standard Practice for Identification of Chemicals in Water by Fluorescence Spectroscopy
• Effective Date: 01-May-2020
• Referred By: ASTM D5389-93(2019) - Standard Test Method for Open-Channel Flow Measurement by Acoustic Velocity Meter Systems
• Effective Date: 01-May-2020

Overview

ASTM D1129-13(2020)e2: Standard Terminology Relating to Water is a foundational standard published by ASTM International, under the jurisdiction of Committee D19 on Water. This terminology standard provides standardized definitions for hundreds of technical terms related to water, water analysis, treatment, and water quality management. Approved for use by organizations such as the U.S. Department of Defense, this standard underpins clear and consistent communication across water-related industries, research, and regulatory activities.

The purpose of ASTM D1129 is to support laboratories, water utilities, environmental specialists, and regulatory agencies by defining essential terminology. By standardizing language, it ensures that technical documents, test procedures, and industry communications are accurate, unambiguous, and in compliance with international principles established by the World Trade Organization's Technical Barriers to Trade (TBT) Committee.

Key Topics

Standardized Water Terminology

• Definitions for water characteristics such as alkalinity, acidity, and biochemical oxygen demand (BOD).
• Terms for measurement, analysis, and quality control (e.g., accuracy, bias, calibration).
• Vocabulary related to water treatment processes (e.g., activated carbon, air stripping, filtration, backwash).
• Hydrological and geological terms (aquifer, alluvium, bedload, base flow).
• Comprehensive definitions for laboratory practices (blank, batch, buffer, calibration curve).
• Specialized technical terms for instrumentation and analytical methodology (acoustic path, amperometric systems, analytical column).

Quality and Compliance

• Clearly describes concepts like acceptable holding time, background sample, best management practice (BMP).
• Supports quality assurance through agreed definitions for critical parameters (batch QC, blank, bias).

Instrumentation and Analytical Methods

• Outlines terminology for modern water analysis instruments, such as automatic programmable sampler, beta particle detection efficiency, analytical columns.
• Provides terms for advanced laboratory methods including back titration, atomic absorption, bubble point test.

Applications

Industry and Water Utilities

• Ensures clear communication in treatment plant protocols, operational guidelines, and maintenance documentation.
• Facilitates compliance with regulatory standards for drinking water, industrial water treatment, and wastewater management.

Laboratory Testing and Environmental Analysis

• Provides a reliable reference for laboratory staff, consultants, and auditors when interpreting test results or developing SOPs.
• Supports accurate data reporting and comparison between organizations by standardizing test method language.

Research, Regulation, and Compliance

• Used by regulatory agencies to define requirements in permits, monitoring programs, and enforcement actions.
• Essential for international collaboration and reporting, as it aligns with globally recognized principles.

Education and Training

• Serves as an authoritative glossary for training new professionals in water quality, hydrology, or environmental science.
• Aids universities and technical schools in curriculum development for water and environmental programs.

Related Standards

Professionals using ASTM D1129 will also benefit from referencing related water standards, such as:

• ASTM D1193: Specification for Reagent Water
• ASTM D5464: Terminology Relating to Water Quality
• ASTM D5906: Practice for Sampling Environmental Waters
• ASTM D6515: Standard Guide for Acceptance of Water Monitoring Methods
• ASTM D6581: Ion Chromatography Terms

In addition, compliance may require alignment with standards from other bodies, such as ISO and EPA, which often cross-reference ASTM water terminology to ensure consistency in global water quality and environmental protection.

---

Keywords: ASTM D1129, water terminology, water quality, water analysis, water treatment, environmental standards, laboratory water testing, water industry standards, water regulation.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
´2
Designation: D1129 − 13 (Reapproved 2020)
Standard Terminology Relating to
Water
This standard is issued under the fixed designation D1129; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—In accordance with D19 bylaws, approved items were added editorially in February 2023.
ε NOTE—In accordance with D19 bylaws, approved items were added editorially in February 2024.
absolute filter rating, n—particle size above which 100 % of accuracy, n—closeness of agreement between an observed
particles that are trapped on or within the filter medium. value and an accepted reference value. Where an accepted
D6161 reference value is not available, accuracy is a description of
a measure of the degree of conformity of a value generated
absorbance, n—logarithm to the base 10 of the reciprocal of
by a specific procedure to the assumed or accepted true
the transmittance (T). A = log (1 ⁄ T) = –log T. D4691
10 10
value, including both precision and bias. D6161
absorption, n—release for desorption holding of a substance
accuracy, n—measure of the degree of conformity of a single
within a solid by cohesive or capillary forces. D6161
test result generated by a specific procedure to the assumed
absorptivity, n—absorbance (A) divided by the product of the or accepted true value, and includes both precision and bias.
D2777
sample path length (b) and the concentration (c). a = A/bc.
D4691
accuracy, n—proportion of the observed count to the true
accelerated erosion, n—erosion at a rate greater than geologic
density of a sample. D5392
or natural erosion. D4410
accuracy, n—refers to how close a measurement is to the true
DISCUSSION—Accelerated erosion is usually associated with anthro-
or actual value. (See Terminology D1129.) D5906
pogenic activities and usually reduces plant cover and increases runoff.
acceptable holding time, n—any period of time less than or acid error, n—in very acid solutions, the activity of water is
equal to the maximum holding time. D4841 reduced (less than unity) causing a non-Nernstian response
in glass electrodes. A positive error in the pH reading results.
acceptable verification ratio (AVR)—ratio of the difference
D4127
between measured value of the verification sample and the
known value added to the verification sample to the square
acidity, n—the quantitative capacity of aqueous media to react
root of the sum of the squares of their associated combined
with hydroxyl ions.
standard uncertainties. See Eq. 8 in 16.2.13. D7282
acidity, n—quantitative capacity of aqueous media to react
accretion, n—process of sediment accumulation. D4410
with hydroxyl ions. D6161
accumulator, n—pulsation dampener installed on the suction
acidity, free mineral, n—the quantitative capacity of aqueous
and/or discharge lines of pumps, generally plunger type, to
media to react with hydroxyl ions to pH 4.3.
minimize pressure surges and provide uniformity of flow.
D6161
acidity, theoretical free mineral, n—the free mineral acidity
that would result from the conversion of the anions of strong
accuracy, n—a measure of the degree of conformity of a value
acids in solution to their respective free acids.
generated by a specific procedure to the assumed or accepted
true value, and includes both precision and bias.
acoustic path, n—straight line between the centers of two
acoustic transducers. D5389
acoustic path length, n—face-to-face distance between trans-
This terminology is under the jurisdiction of ASTM Committee D19 on Water
ducers on an acoustic path. D5389
and is the direct responsibility of Subcommittee D19.12 on Terminology.
Current edition approved May 1, 2020. Published June 2020. Originally
acoustic transducer, n—device that is used to generate acous-
approved in 1950. Last previous edition approved in 2013 as D1129 – 13. DOI:
10.1520/D1129-13R20E02. tic signals when driven by an electric voltage, and
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´2
D1129 − 13 (2020)
conversely, a device that is used to generate an electric air scour, v—distributing air over the entire area at the bottom
voltage when excited by an acoustic signal. D5389 of a filter media flowing upward or immersed membrane to
improve the effectiveness of filtration or backwashing or to
acoustic travel time, n—time required for an acoustic signal to
permit the use of lower backwash water flow rate, or both.
propagate along an acoustic path, either upstream or
D6161
downstream. D5389
air stripping, v—removal of volatile substances from a water
action level, n—concentration of the analyte of concern at
solution by passing a gas through the solution. D6161
which some further action is required or suggested. D6850
algae, n—major group of lower plants, generally aquatic,
photosynthetic of extremely varied morphology and
activated carbon, n—granulated or powdered activated carbon
physiology, monocellular plants with chlorophyll often
used to remove tastes, odor, chlorine, chloramines, and some
masked by a brown or red pigment. D6161
organics from water. A family of carbonaceous substances
manufactured by processes that develop adsorptive
alkaline error, n—in alkaline solutions, where hydrogen ion
properties. D6161
activity becomes very small, some glass electrodes respond
to other cations, such as sodium. A negative error in the pH
activity, n—thermodynamically effective concentration of a
reading results. By changing the composition of the glass,
free ion in solution. In dilute solutions, ionic activity and
the affinity of the glass for sodium ion can be reduced. Such
concentration are practically identical, but in solutions of
electrodes are known as lithium glass, high-pH, or full-range
high ionic strength, or in the presence of complexing agents,
electrodes. D4127
activity may differ significantly from concentration. Ionic
activity, not concentration, determines both the rate and the
alkalinity, n—the quantitative capacity of aqueous media to
extent of chemical reactions. D4127
react with hydrogen ions.
alkalinity, n—quantitative capacity of aqueous media to react
activity coefficient, n—factor, γ, that relates activity, A, to the
with hydrogen ions. “M” alkalinity is that which will react
concentration, C of a species in solution:
with acid as the pH of the sample is reduced to the
A 5 γC
methylorange endpoint of about 4.5. “P” alkalinity is that
The activity coefficient is dependent on the ionic strength
which reacts with acid as the pH of the sample is reduced to
of the solution. Ions of similar size and charge have similar
the phenolphthalein end point of 8.3. “M” is the total
activity coefficients. D4127
alkalinity which is the sum of hydroxide, carbonate, and
bicarbonate contents, “P” includes all the hydroxyl and half
activity standard, n—standardizing solution whose value is
the carbonate content. D6161
reported in terms of ionic activity. If the electrode is
alkyl benzene sulfonate (ABS)—generic name applied to the
calibrated using activity standards, the activity of the free,
neutralized product resulting from the sulfonation of a
unbound ion in the sample is determined. D4127
branched-chain alkylated benzene. See also Terminology
adenosine triphosphate—see ATP. D6161
D459. D2330
adsorption, n—holding of a substance onto the surface of a
alluvial channel—see alluvial stream. D4410
solid by chemical surface forces, without forming new
alluvial deposit—sediment deposited by the action of moving
chemical bonds. D6161
water. D4410
aerobic bacteria, n—bacteria that require oxygen for growth.
alluvial fans—sediment deposited in the shape of a segment of
See bacteria, aerobes. D6161
a cone formed because of a sudden flattening of a stream
gradient especially at debouchures of tributaries on main
aerosol, n—any solid or liquid particles, with a nominal size
stream flood plains. D4410
range from 10 nm to 100 μm, suspended in a gas (usually
air). D5544
alluvial stream, n—stream whose boundary is composed of
appreciable quantities of the sediments transported by the
agglomeration or flocculation, n—coalescence of dispersed
flow and which generally changes its bed forms as the rate of
suspended matter into large flocs or particles that settle
flow changes. D4410
rapidly. D4410
alleviation, n—process of accumulating sediment deposits at
aggradation, n—geologic process by which stream beds, flood
places where the flow is retarded. D4410
plains, and the bottoms of other water bodies are raised in
alluvium, n—general term for all fluvial deposits resulting
elevation by the deposition of material eroded and trans-
directly or indirectly from the sediment transport of (mod-
ported by water from other areas. D4410
ern) streams, thus including the sediments laid down in
aggregate, n—granular material such as sand, gravel, or
riverbeds, flood plains, lakes, fans, and estuaries. D4410
crushed stone. D6161
For a more complete discussion of terms relating to synthetic detergents and
air header, n—pipe running within a cassette that distributes
their significance, refer to McKinney, R. E., “Syndets and Waste Disposal,” Sewage
the air to the individual modules or aerators. D6161 and Industrial Wastes, Vol 29, Part 6, June 1957, pp. 654–666.
´2
D1129 − 13 (2020)
alpha (α), n—velocity-head coefficient that adjusts the velocity amorphous, adj—noncrystalline, devoid of regular cohesive
head computed on basis of the mean velocity to the true structure. D6161
velocity head. D5129
amperometric systems, n—those instrumental probes that
alpha (α), n—velocity-head coefficient that adjusts the velocity
involve the generation of an electrical current from which
head computed on basis of the mean velocity to the true
the final measurement is derived. D888
velocity head. It is assumed equal to 1.0 if the cross section
amphoteric, adv—capable of acting as an acid or a base.
is not subdivided. D5243
D6161
alpha (α), n—velocity-head coefficient that represents the ratio
anaerobic bacteria, n—bacteria that do not use oxygen.
of the true velocity head to the velocity head computed on
Oxygen is toxic to them. See bacteria, anaerobes. D6161
the basis of the mean velocity. It is assumed equal to 1.0 if
the cross section is not subdivided. For subdivided sections,
analate addition, n—variation of the known addition measure-
a is computed as follows: D5130
ment technique in which the sample (analate) is added to a
reagent containing the ion being measured. The electrode is
k
i
S D
( 2
placed in the reagent, and the sample concentration is
A
i
α 5
calculated from the change in electrode potential after the
K
T
addition of the sample. D4127
A
T
where: analate subtraction, n—variation of the known subtraction
measurement technique in which the sample (analate) is
K and A = the conveyance and area of the subsection
added to a reagent containing an ion that reacts with the
indicated by the subscript i, and
species being determined. The electrode is placed in the
K and A = the conveyance and area of the entire cross
T T
reagent, the change in electrode potential is observed when
section.
the sample is added, and the sample concentration calcu-
alpha (α), n—dimensionless velocity-head coefficient that
lated. D4127
represents the ratio of the true velocity head to the velocity
analyte, n—a possible sample component whose presence and
head computed on the basis of the mean velocity. It is
concentration is of interest.
assumed equal to unity if the cross section is not subdivided.
For subdivided sections, a is computed as follows: D5388
analyte, n—chemical or constituent being determined. D5463
k
i
S D analytical column, n—chromatography column that contains
( 2
a
i
α 5
the stationary phase for separation by ion exchange. The
K
T
column is packed with anion exchange resin that separates
A
T
the analytes of interest based on their retention characteris-
where:
tics before detection. D6994
k and a = the conveyance and area of the subsection
analytical column, n—column used to separate the anions of
indicated by the subscript i, and
interest. D5996
K and A = the conveyance and area of the total cross
T T
section indicated by the subscript T.
analytical column, n—ion exchange column used to separate
the ions of interest according to their retention characteristics
alpha particle (α), n—particle consisting of two protons and
prior to detection. D6581
two neutrons emitted from the nucleus of an atom during
radioactive decay. D7316
analytical column set, n—combination of one or more guard
columns, followed by one or more analytical columns used
alpha particle detection efficiency, n—in the measurement of
to separate the ions of interest. All of the columns in series
radioactivity, that fraction of alpha particles emitted by a
then contribute to the overall capacity and resolution of the
source which are identified as alpha particles by the counter.
analytical column set. D6581
D7283
analytical column set, n—combination of one or more guard
alpha-to-beta spillover, n—in the measurement of
columns followed by one or more analytical columns.
radioactivity, that fraction of alpha particles emitted by a
D5996
source which are misclassified as beta particles. D7283
analytical columns, n—combination of one or more guard
alum, n—aluminum sulfate, AL (SO ) XH O (X = 14-18), a
2 4 3 2
columns followed by one or more separator columns used to
coagulant. D6161
separate the ions of interest. It should be remembered that all
ambient temperature, n—temperature of the surroundings,
of the columns in series contribute to the overall capacity of
generally assumed to be 20–25°C. D6161
the analytical column set. D4327
American Water Works Association—see AWWA. D6161
analytical columns, n—combination of one or more guard
American Water Works Association Research columns followed by one or more separator columns used to
Foundation—see AWWARF. D6161 separate the ions of interest. It should be remembered that all
´2
D1129 − 13 (2020)
of the columns in series contribute to the overall capacity of anode, n—positive electrode. D6161
the analytical column set. D5542
anthracite, n—granular hard coal used as a filtration media,
analyze, v—to determine the relationship of parts or the value commonly used as the coarser layer in dual and multimedia
filters. D6161
of a particular parameter. D5851
analyzer—see monitoring system. D3864 antidunes, n—bed forms that occur at a velocity higher than
that velocity that forms dunes and plane beds. Antidunes
-10 -4
angstrom (A), n—unit of length equaling 10 metres, 10
commonly move upstream, and are accompanied by, and in
-8 -9
umetres, 10 centimetres, and 3.937 × 10 in. The symbol
phase with, waves on the water surface. D4410
is Å, A, or A.U. D6161
antifoulant, n—see antiscalant. D6161
animal/vegetable-derived oils, n—mixture made of mono-,
antiscalant, n—compound added to a water that inhibits the
di-, and triglyceride esters of fatty acids and other substances
precipitation of sparingly soluble inorganic salts. D6161
of animal or vegetable origin, or both. D3326
anti-telescoping device, n—plastic or metal device attached to
anion, n—negatively charged ion. D6161
the ends of a spiral wound cartridge to prevent movement of
anion exchange chromatography, n—type of liquid chroma-
the cartridge leaves in the feed flow direction as a result of
tography in which anionic analytes are separated by differ-
high feed flows. D6161
ential retention on an anion exchange resin and detected by
approach angle, n—angle between the velocity vector of the
an appropriate detection mechanism. D6994
approaching flow and the centerline of the nozzle. D6326
anion-exchange material, n—a material capable of the revers-
approaching flow, n—flow immediately upstream of a nozzles
ible exchange of negatively charged ions.
entrance. D6326
anion-exchange material, n—ion-exchange material capable
aquatic free cyanide, n—sum of the free cyanide (HCN and
of the reversible exchange of negatively charged ions.
-
CN ) and cyanide bound in the metal-cyanide complexes that
D2187
are easily dissociated into free cyanide under the test
conditions described in this method. D7237
anion-exchange material, n—ion-exchange material capable
of the reversible exchange of negatively charged ions.
aquifer, n—geologic formation containing water, usually able
D4548
to yield appreciable water. D6146
anion exchange material, n—material capable of the revers-
aquifer, n—water-bearing geological formation that provides a
ible exchange of negatively charged ions. D6161
ground water reservoir. D6161
anion exchange membrane, n—membrane containing fixed
aramid, n—fully aromatic polyamide. D6161
cationic charges and mobile anions that can be exchanged
area (A), n—area of a cross section, parts of a cross section, or
with other anions present in an external fluid in contact with
parts of bridges below the water surface. Subscripts indicate
the membrane. D6161
specific areas as follows: D5129
anion suppressor device, n—device that is placed between the
A = area of subsection I,
analytical columns and the detector. Its purpose is to inhibit
i
A = area of piers or piles that is submerged,
detector response to the ionic constituents in the eluant so as
j
A = area of total cross-section 1 (see Fig. 1 of D5129), and
to lower the detector background and at the same time 1
A = gross area of Section 3 of D5129.
enhance detector response to the ions of interest. D5996
armoring, v—formation of a resistant layer of relatively large
anion trap column, n—high-capacity, low-pressure anion
particles by erosion of the finer particles. D4410
exchange column used to remove reagent impurities from
the eluent stream. The anion trap column is placed between
array, n—arrangement of devices connected to common feed,
the eluent reservoir and the gradient pump. D6994
product, and reject headers; that is, a 2:1 array. D6161
anionic polyelectrolyte, n—usually acrylamide or acrylamide
assess, v—to determine importance of data. D5851
and acrylic copolymers, negatively charged, used for
assess, v—to determine the significance, value, and importance
coagulation/flocculation. See polyelectrolyte. D6161
of the data collected and recorded. D6145
anisotropic, adv—having different optical properties in differ-
assimilable organic carbon, n—see AOC. D6161
ent optical planes. These planes are referred to as the alpha,
beta, and omega axes. D1245
asymmetric membrane, n—membrane that has a change in
pore structure. See anisotropic membranes. D6161
anisotropic membrane, n—nonuniform structure in cross
section; typically the support substructure has pores much asymmetry potential, n—potential across a glass pH electrode
larger than the barrier layer. See asymmetric membranes. membrane when the inside and outside of the membrane are
D6161 in contact with solutions of identical pH. This term has also
´2
D1129 − 13 (2020)
been used to define the observed potential differences background sample, n—sample taken from a location on or
between identical electrode pairs placed in identical solu- proximate to the site of interest. This sample is taken to
tions. D4127 document baseline or historical information. D5612
Atmospheric Pressure Chemical Ionization (APCI), n—an background subtraction count (BSC)—a source count used
ionization method used in mass spectrometry which uses a
to determine the background to be subtracted from the
gas-phase ion-molecule reaction at atmospheric pressure sample test source count. D7282
coupled with high-performance liquid chromatography
backpulse, n—pumping treated water with or without added
(HPLC).
chemicals in the reversed direction from the lumen to the
DISCUSSION—APCI is a soft ionization method similar to chemical
feed side of the membrane (inside out). D6161
ionization where primary ions are produced on a solvent spray. The
main usage of APCI is for mid-polar and relatively less polar thermally
backwash, n—reversing the flow of water with/without air
stable compounds with molecular weight less than 1500 Da. D8456
either across or through a medium or membrane. Designed
atomic absorption, n—absorption of electromagnetic radia-
to remove the collected foreign material from the bed or
tion by an atom resulting in the elevation of electrons from
membranes. D6161
their ground states to excited states. Atomic absorption
bacteria, n—any of a class of microscopic single-celled
spectrophotometry involves the measurement of light ab-
organisms reproducing by fission or by spores. Character-
sorbed by atoms of interest as a function of the concentration
ized by round, rod-like, spiral, or filamentous bodies, often
of those atoms in a particular solution. D4691
aggregated into colonies or mobile by means of flagella.
automatic programmable sampler, n—portable device de-
Widely dispersed in soil, water, organic matter, and the
signed to collect sequential, discrete water samples repre-
bodies of plants and animals. Either autotrophic (self-
sentative of the water mixture moving in the river in the
sustaining, self-generative), saprophytic (derives nutrition
vicinity of the sampler at a single point in a cross section.
from nonliving organic material already present in the
Depending on the make and model of the device, water
environment), or parasitic (deriving nutrition from another
samples can be collected at equal or variable time intervals.
living organism). Often symbiotic (advantageous) in man,
D5613
but sometimes pathogenic. D6161
autopsy, n—dissection of a membrane module or element to
bacterial lawn, n—confluent growth of bacteria cultured on an
investigate causes of unsatisfactory performance. D6161
agar plate. D6734
available cyanide—inorganic cyanides that are free (HCN and
bactericide, n—agent capable of killing bacteria. D6161
-
CN ) and metal-cyanide complexes that are easily dissoci-
bacteriostat, n—substance that prevents bacterial growth and
ated into free cyanide ions. Available cyanide does not
metabolism but does not necessarily kill them. D6161
include the less toxic strong metal-cyanide complexes,
cyanides that are not “amenable to chlorination.” D6888
baffle, n—deflector plate in a vessel that disperses the inlet
availability, n—on-stream time or rated operating capacity of fluid. D6161
a water treatment system. D6161
bag sampler—a sampler that uses a collapsible bag as the
a-value, n—membrane water permeability coefficient. The
sample collection container. D4410
coefficient is defined as the amount of water produced per
bank, n—grouping of devices. See array, block, train. D6161
unit area of membrane per unit of net driving pressure
(NDP); units of measurement are m3/h/m2/kPa. D6161
bar, n—section of metallic channel, I-beam, T-beam, pipe,
plate, or ball that will reflect sound waves produced by a
avulsion, n—sudden, natural change of a stream channel, so
fathometer. D6318
that the water flows elsewhere than in its previous course.
2 2
D4410
bar, n—unit of pressure; 14.50 lbs/in. , 1.020 kg/cm , 0.987
atm, 0.1 MPa. D6161
B-value—salt diffusion coefficient, n—defined as the amount
of salt transferred per unit area of membrane per unit of
bar-check, n—method for calibrating a fathometer by setting a
concentration difference across the membrane. A unit of
sound or acoustic reflector (bar) below a survey vessel to a
3 2
measurement is m/h or more specifically, m /m /h. D6161
known depth below a sounding transducer. D6318
back pressure regulator—a device designed to maintain a
bar-check, n—method for determining depth below a survey
constant pressure upstream of itself (variable or fixed back
vessel by means of a long, narrow metal bar or beam
pressure regulators are available) to maintain constant flow
suspended on a marked line beneath a sounding transducer.
in analyzers in continual sampling. D3370
D5073
back titration, n—see titration. D4127
bar sweep, n—bar or pipes, suspended by wire or cable
backflush, n—temporary reversal of the permeate or retentate beneath a floating vessel, used to search for submerged snags
flow. D6161 or obstructions hazardous to navigation. D5073
´2
D1129 − 13 (2020)
base flow, n—stream flow that is sustained by ground water refractive index between the crystal and the oil increases.
and other delayed sources. D4410 D1245
batch, n—in the analysis of water, a group of samples to be Becquerel, n—unit of radioactivity equivalent to one nuclear
analyzed, assembled in such a way that all the variables transformation per second. D1890
affecting the batch will affect all the samples and standards
bed depth, n—depth of the filter medium or ion exchange resin
in the batch in a statistically equivalent manner.
in a vessel. D6161
DISCUSSION—Batching is a fundamental quality-control component.
With properly constructed batches, the results of quality control
bed expansion, n—depth increase of filter medium or ion
elements can be used reliably to identify out-of-control situations in the
exchange resin that occurs during backwashing. D6161
analytical system and to assign uncertainty to individual results from
the batch.
bed-load, n—material moving on or near the stream bed by
rolling, sliding, and skipping. D4410
batch, adj—in the analysis of water, characterizing standards
that are carried through all of the analytical steps attached to
bed-load discharge, n—quantity of bed-load passing a cross
the analytical method being employed.
section of a stream in a unit of time. D4410
batch, n—set (group) of samples analyzed such that results of
bed-load sampler, n—device for sampling the bed-load.
analysis of the QC samples (laboratory control sample, D4410
method blank, matrix spike, and duplicate or matrix spike
bed material, n—sediment mixture of which the stream bed is
duplicate) analyzed with the batch are indicative of the
composed. D4410
quality of the results of analysis of samples in the batch. The
number of samples in the batch is defined by the task group bed-material discharge, n—that part of the total sediment
responsible for the method. See 6.4 and Explanation 2 in
discharge composed of grain sizes occurring in appreciable
Appendix X1 of Practice D5847. D5847 quantities in the bed material. D4410
DISCUSSION—When results from tests of any of the QC samples
bed-material load, n—that part of the total load which is
associated with the batch fail to meet the performance criteria, the test
composed of particle sizes present in appreciable quantities
method should define the appropriate corrective action. To make such
a response valid, the batch shall be constructed in such a way as to in the shifting portions of the stream bed. D4410
assure that all variables affecting the batch will affect all samples in the
best available technology—see BAT. D6161
batch in a statistically equivalent manner.
best management practice (BMP), n—practice or combina-
batch, n—set (group) of samples analyzed such that results of
tion of practices that are determined by state or area-wide
analysis of the QC samples analyzed with the batch are
planning agencies to be the most effective and practical
indicative of the quality of the results of analysis of samples
means of controlling point and nonpoint pollution. D6145
in the batch. The number of samples in the batch is defined
by the task group responsible for the method. D6850
beta energy, maximum, n—maximum energy of the beta-
DISCUSSION—See Practice D5847 for definition and discussion of
particle energy spectrum produced during beta decay of a
batch and batch size.
given radioactive species. D1890
DISCUSSION—Since a given beta-particle emitter may decay to several
batch QC, n—all the quality control samples and standards
different quantum states of the product nucleus, more than one
included in an analytical procedure. D8024
maximum energy may be listed for a given radioactive species.
baseline, n—primary reference line for use in measuring
beta energy, maximum, n—the maximum energy of the beta
azimuth angles and positioning distances. D5906
particle energy spectrum produced during beta decay of a
baume scale, Be, n—measure of the density of a solution given radionuclide.
DISCUSSION—Since a given beta emitter may decay to several
relative to water. D6161
different nuclear energy levels of the progeny, more than one maximum
energy may be listed for a given radionuclide. D7283
BE 5 145 2
specific gravity*
beta particle (β), n—electron or positron emitted from the
United States for densities greater than unity.
nucleus of an atom during radioactive decay. D7316
BE 5 2 130
beta particle detection efficiency, n—in the measurement of
specific gravity*
radioactivity, that fraction of beta particles emitted by a
For densities less than unity.
source which are identified as beta particles by the counter.
*at 60°F
D7283
beam width, n—angle in degrees made by the main lobe of beta-to-alpha spillover, n—in the measurement of
acoustical energy emitted from the radiating face of a
radioactivity, that fraction of beta particles emitted by a
transducer. D5073
source which are misclassified as alpha particles. D7283
Becke line, n—faint, halo-like line that surrounds a crystal bias, n—the persistent positive or negative deviation of the
when the crystal is mounted in an oil of different refractive method average value from the assumed or accepted true
index. It increases in intensity as the difference in the value.
´2
D1129 − 13 (2020)
bias, n—persistent positive or negative deviation of the aver- bottom profile, n—line trace of the bottom surface beneath a
age value of a test method from the assumed or accepted true water body. D5073
value. D2777
bottomset bed, n—fine-grained material (usually silts and
bias, n—persistent positive or negative deviation of the aver-
clays) slowly deposited on the bed of a quiescent body of
age value of the test method from the assumed or accepted
water which may in time be buried by foreset beds and topset
true value. D5392
beds. D4410
binders, n—in reference to cartridge filters, chemicals used to
boulder size (fluvial sediment), n—larger than 256 mm in
hold, or “bind,” short fibers together in a filter. D6161
diameter. D4410
binding, n—in surface filtration, a buildup of particulates on
boundary layer, n—relatively thin layer of viscous influence
the filter, restricting fluid flow through the filter at normal
adjacent to the probe (or any solid) surface caused by the
pressures. D6161
requirement that the water velocity must be zero at the wall.
D5089
biochemical oxygen demand (BOD), n—the quantity of
oxygen consumed in the biological and chemical oxidation
boundary layer, n—thin layer at the membrane surface where
of water-borne substances under conditions of test.
water velocities are significantly less than those in the bulk
flow. D6161
biocide, n—substance that kills all living organisms. D6161
boundary layer displacement thickness, n—boundary layer
biodegradable plastic, n—degradable plastic in which the
is a layer of fluid flow adjacent to a solid surface (in this
degradation results from the action of naturally occurring
case, the flume throat) in which, owing to viscous friction,
microorganisms such as bacteria, fungi, and algae. D6888
the velocity increases from zero at the stationary surface to
biological deposits, n—deposits of organisms or the products
an essentially frictionless-flow value at the edge of the layer.
of their life processes.
The displacement thickness is a distance normal to the solid
surface that the surface and flow streamlines can be consid-
biological deposits, n—debris left by organisms as a result of
ered to have been displaced by virtue of the boundary-layer
their life processes. D6161
formation. D5390
biological deposits—water-formed deposits of organisms or
boundary layer displacement thickness, n—boundary layer
the products of their life processes. D887
is a layer of fluid flow adjacent to a solid surface (in this
biomass, n—any material that is or was a living organism or
case, the weir crest and sidewalls) in which, because of
excreted from a microorganism. D6161
viscous friction, the velocity increases from zero at the
stationary surface to an essentially frictionless-flow value at
bioremediation, n—biological degradation treatment of waste
the edge of the layer. The displacement thickness is a
sludge and soils to breakdown organic and hydrocarbons.
distance normal to the solid surface that the flow streamlines
D6161
can be considered to have been displaced by virtue of the
boundary-layer information. D5614
biostat, n—substance that inhibits biological growth. D6161
bipolar membrane, n—synthetic membrane containing two
brackish water, n—water that contains dissolved matter at an
oppositely charged ion-exchange layers that are in contact approximate concentration range from 1000 to 30 000 mg/L.
with each other. D6161
brackish water, n—water with an approximate concentration
blackwater, n—increase in the depth of flow upstream of a
of total dissolved solids ranging from 500 to 10 000 mg/L.
channel obstruction, in this case, a weir or flume. D5640
See high brackish water, potable water, sea water. D6161
blank, n—matrix carried through all or part of the analytical
braided river, n—wide- and shallow-river where the flow
process, where the analyte is not present, or where the
passes through a number of small interlaced channels
analyte response is suppressed.
separated by bars or shoals. D4410
NOTE 1—A blank must be appropriate to the analytical process it is
brackish water reverse osmosis, n—see BWRO. D6161
being used with.
NOTE 2—A blank is typically used to monitor contamination or to
breakpoint chlorination, n—point at which the water chlorine
establish a baseline for quantitation.
demand is satisfied and any further chlorine is the chlorine
residual, the “free” chlorine species. D6161
block, n—grouping of devices in a single unit having common
control. See array, bank, train. D6161
break tank, n—storage device used for hydraulic isolation and
BOD, n—biochemical oxygen demand. surge protection. D6161
body feed, v—continuous addition of filter medium (for breakthrough volume, n—maximum sample volume that can
example, diatomaceous earth) to sustain the efficacy of the be passed through a concentrator column before the least
filter. D6161 tightly bound ion of interest is eluted. D5542
´2
D1129 − 13 (2020)
breakthrough volume, n—maximum sample volume that can calculated by multiplying concentration in mg/L of the ion
be passed through a concentrator column before the least by the equivalent weight of calcium carbonate (50) and
tightly bound ion of interest is eluted. All of the columns in dividing by the equivalent weight of the ion. (See Table 1 of
series contribute to the overall capacity of the analytical Terminology D6161). D6161
column set. D5996
calcium hypochlorite, n—Ca (HCIO) , a disinfection agent.
brine, n—water that contains dissolved matter at an approxi- D6161
mate concentration of more than 30 000 mg ⁄L.
calibration, n—in the analysis of water, the analysis of
standards to develop a relationship between raw output of an
brine, n—concentrate (reject) stream from a crossflow mem-
analytical system and analyte concentration.
brane device performing desalination. Portion of the feed
DISCUSSION—Calibration can be done with traceable or non-traceable
stream that does not pass through the membrane. D6161
standards. Calibration can be done with standards that are processed
identically to samples to produce “true” results, unbiased by recovery
brine, n—water that contains dissolved matter at an approxi-
(of the standard), or calibration can be done with unprocessed
mate concentration of more than 30 000 mg ⁄L. D1429
standards, typically in situations where recovery is not considered a
significant issue.
brine (concentrate) seal, n—rubber lip seal on the outside of
a spiral wound cartridge that prevents feed by-pass between
calibration, n—certified evaluation of the accuracy of a
the cartridge and the inside pressure vessel wall. D6161
measuring instrument as performed by its manufacturer or an
independent licensed or accredited third party. D6104
brine seal carrier, n—see ATD. D6161
calibration, n—certified evaluation of the accuracy of a
brine system staging, n—process in which the concentrate,
measuring instrument as performed by its manufacturer or an
under pressure, of a group of membrane devices is fed
independent licensed or accredited third party. D6157
directly to another set of membrane devices to improve the
efficiency of the water separation. D6161
calibration—determining the instrument response to a known
amount of radioactive material. D7282
bubble point, n—pressure differential at which bubbles first
appear on one surface of an immersed porous membrane as
calibration blank, n—volume of water containing the same
gas pressure is applied to the other side. D6161
acid matrix as the calibration standards. D1976
calibration blank, n—volume of water containing the same
bubble point, n—when the pores of a membrane are filled with
liquid and air pressure is applied to one side of the acid matrix as the calibration standards. D5673
membrane, surface tension prevents the liquid in the pores
calibration curve, n—plot of the potential (emf) of a given
from being blown out by air pressure below a minimum
ion-selective electrode cell assembly (ion-selective electrode
pressure known as the bubble point. D6908
combined with an identified reference electrode) versus the
logarithm of the ionic activity (concentration) of a given
bubble point pressure, n—pressure differential necessary to
species. For uniformity, it is recommended that the potential
displace a liquid held by surface tension forces from the
be plotted on the ordinate (vertical axis) with the more
largest equivalent capillaries in a membrane filter. D6161
positive potentials at the top of the graph and that pa (-log
A
bubble point test, n—nondestructive membrane filter test used
activity of the species measured, A) or pc (-log concentra-
A
to assess filter integrity and proper installation. D6161
tion of species measured, A) be plotted on the abscissa
(horizontal axis) with increasing activity to the right.
buffer, n—substance in solution that accepts hydrogen or
IUPAC, D4127
hydroxyl ions added to the solution minimizing a change in
pH. D6161
calibration curve, n—functional model that calculates count-
ing efficiency from the value of a predictor variable and one
build, own, operate—see BOO. D6161
or more model parameters; also known as an effıciency
build, own, operate and transfer—see BOOT. D6161
curve.
DISCUSSION—A calibration “curve” might be a linear or nonlinear
bundle, n—general term for a collection of parallel filaments
function of the predictor variable. D8537
or fibers. D6161
calibration parameter, n—any of the parameters in a calibra-
cage, n—structural fabrication fitted around the perimeter of
tion model whose values are determined by a calibration and
the cassette with one or more lifting eye suitable for
subsequently used together with observed values of the
installing or removing the cassette. The four bottom corners
predictor variable to calculate counting efficiencies. D8537
of the cage rest within the frame in the tank. D6161
calibration range, n—interval between the least and greatest
cake layer, n—layer comprised of particulate materials resid-
values of the predictor variable for which a calibration curve
ing on the upstream face of a membrane. D6161
is considered valid. D8537
calcium carbonate equivalents (mg/L as CaCO ), calibration source (CS)—a known quantity of radioactive
n—method for expressing mg/L as ion in terms of calcium material, traceable to a national standards body, prepared for
carbonate. Concentration in calcium carbonate equivalents is the purpose of calibrating nuclear instruments. D7282
´2
D1129 − 13 (2020)
calibration standard, n—solution prepared from the primary perform calibrations, only calibration verifications. Included
dilution standard solution and stock standard solutions of the standards are optomechanical light scatter devices, gel-like
internal standards and surrogate analytes. The calibration standards, or any other type of stable liquid standard. D6855
DISCUSSION—Calibration verification standards may be instrument
standards are used to calibrate the instrument response with
specific.
respect to analyte concentration. D5790
calibrations:
calibration standard, n—solution containing the analyte of
laboratory check sample for flow-through systems,
interest at a known concentration either purchased from an
n—calibration curve calculated from withdrawn samples or
external source or prepared in-house from materials of
additional standards that may be spiked or diluted and analyzed
known purity or concentration, or both, and used to calibrate
using the appropriate laboratory analyzer. D3864
the measurement system. D5847
line sample calibration, n—coincidental comparison of a
calibration standard (CAL), n—solution prepared from the
line sample and adjustment of a continuous analyzer to the
primary dilution standard solution and stock standard solu-
compared laboratory analyzer or a second continuous analyzer.
tions of the internal standards and surrogate analytes. CAL
D3864
solutions are used to calibrate the instrument response with
multiple standard calibration, n—where the calibration
respect to analyte concentration. D5315
curve is calculated from a series of calibration standards
calibration standard (CAL), n—solution prepared from the
covering the range of the measurements of the sample being
primary dilution standard solution and stock standard solu-
analyzed. D3864
tions of the internal standards and surrogate analytes. D5475
probe calibration, n—where the probe is removed from the
DISCUSSION—The CAL solutions are used to calibrate the instrument
sample stream and exposed to a calibration solution and the
response with respect to analyte concentration.
analyzer is adjusted to indicate the appropriate value.
calibration standards, n—series of known standard solutions
Alternately, two probes are exposed to the same solution and
used by the analyst for calibration of the instrument (prepa-
the on-line analyzer is adjusted to coincide with the pre-
ration of the analytical curve). D1976
calibrated laboratory instrument. D3864
reference sample calibration, n—coincidental comparison of
calibration standards, n—series of known standard solutions
a reference sample and adjustment of a continuous analyzer to
used by the analyst for calibration of the instrument (that is,
the compared laboratory analyzer results. D3864
preparation of the analytical curve). D5673
capillary ion electrophoresis, n—electrophoretic technique in
calibration stock solution, n—solution prepared from the
which a UV-absorbing electrolyte is placed in a 50- to 75-μm
stock standard solution(s) to verify the instrument response
fused silica capillary. Voltage is applied across the capillary
with respect to analyte concentration. D5673
causing electrolyte and anions to migrate towards the anode
calibration turbidity standard, n—turbidity standard that is
and through the capillary’s UV detector window. Anions are
traceable and equivalent to the reference turbidity standard
separated based upon the their differential rates of migration
to within statistical errors, including commercially prepared
in the electrical field. Anion detection and quantitation are
4000 NTU Formazin, stabilized formazin, and styrenedivi-
based upon the principles of indirect UV detection. D6508
nylbenzene (SDVB). These standards may be used to cali-
carbamates, n—in Test Method D7645, aldicarb, aldicarb
brate the instrument. D6698
sulfone, aldicarb sulfoxide, carbofuran, methomyl, oxamyl,
DISCUSSION—Calibration standards may be instrument specific.
and thiofanox collectively. D7645
calibration turbidity standard, n—a turbidity standard that is
carbonate hardness, n—hardness in a water caused by car-
traceable and eq
...