ISO/FDIS 5667-10

• Abstract:

  This document contains details on the sampling of domestic and industrial waste water, i.e. the design of sampling programmes and techniques for the collection of samples. It covers waste water in all its forms, i.e. industrial waste water, radioactive waste water, cooling water, raw and treated domestic waste water. It deals with various sampling techniques used and the rules to be applied so as to ensure the samples are representative. Sampling of accidental spillages is not included, although the methods described in certain cases may also be applicable to spillages.

• Status: Not Published
• ICS: 13.060.25 - Water for industrial use
• ICS: 13.060.30 - Sewage water
• Technical Committee: ISO/TC 147/SC 6 - Sampling (general methods)
• Drafting Committee: ISO/TC 147/SC 6 - Sampling (general methods)
• Current Stage: 5000 - FDIS registered for formal approval
• Start Date: 15-Apr-2026
• Completion Date: 08-Aug-2026

• Revises: ISO 5667-10:2020 - Water quality — Sampling — Part 10: Guidance on sampling of waste water
• Effective Date: 29-Apr-2023

FINAL DRAFT
International
Standard
ISO/TC 147/SC 6
Water quality — Sampling —
Secretariat: BSI
Part 10:
Voting begins on:
2026-08-20
Waste water
Voting terminates on:
2026-10-15
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
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MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 147/SC 6
Water quality — Sampling —
Secretariat: BSI
Part 10:
Voting begins on:
Waste water
Voting terminates on:
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
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BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
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ii
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General aspects . 4
4.1 Design of sampling programme .4
4.2 Sampling point selection — Representativeness .4
4.3 Frequency and time of sampling .4
4.3.1 Number of samples .4
4.3.2 Sampling time for effluent stream .5
5 Sampling at specific locations . . 6
5.1 General .6
5.2 Sampling from sewers, channels and manholes .6
5.3 Sampling from waste water treatment plant .7
5.4 Sampling from industrial sites .7
5.5 Sampling from cooling systems .8
6 Main types of waste waters sampling . 9
6.1 Spot sampling .9
6.2 Composite sampling .9
7 Waste water sampling . 9
7.1 General aspects .9
7.1.1 General .9
7.1.2 Preparation of the sampling campaign .10
7.1.3 Arrival on site .10
7.2 Composite sampling for waste waters quality monitoring .10
7.2.1 General .10
7.2.2 Automatic composite sampling .11
7.2.3 Manual composite sampling.14
7.2.4 Manual sample reconstitution .14
7.3 Spot sampling in an effluent stream . 15
7.3.1 General . 15
7.3.2 Direct sampling .16
7.3.3 Indirect sampling .16
7.3.4 Automatic, remote start or event-triggered sampling .17
7.4 Spot sampling of storage containers — Planned discharges .17
8 Sampling equipment .18
8.1 General .18
8.2 Automatic sampler .18
8.3 Manual sampling equipment .19
8.3.1 General .19
8.3.2 Ballasted sample collector . .19
8.3.3 Bucket, vertical water sampler .19
8.4 Storage container sampling equipment . 20
8.4.1 Mixing . 20
8.4.2 Sampling equipment . 20
9 Homogenization, preservation, transport and storage of samples .20
9.1 Homogenization of collected volume . 20
9.2 Distribution of collected volume into laboratory bottles .21
9.3 Preservation and packaging of samples .21
9.4 Transportation and reception . 22
9.4.1 General . 22
9.4.2 Time . 22

iii
9.4.3 Temperature . 22
9.5 Security and traceability of samples during storage and delivery . 22
9.5.1 Routine samples . 22
9.5.2 Samples which can be used for legal purposes . 23
10 Quality assurance .23
10.1 Risk of contamination . 23
10.2 Sample identification and records . 23
10.3 Assurance and quality control .24
11 Reports .24
11.1 Analytical reports . .24
11.2 Sampling protocols . 25
12 Safety precautions.25
12.1 General . 25
12.2 Personnel safety . 26
12.3 Equipment safety . . 26
Annex A (informative) Examples of sampling from storage containers .28
Annex B (informative) Advantages and disadvantages of main types of waste waters sampling .31
Annex C (informative) Example of cleaning protocol — Sampling equipment .34
Annex D (informative) Example of a field form — Waste waters sampling .36
Annex E (informative) Choice of compatible materials for automatic samplers .38
Annex F (informative) Comparison of pumping types: PP, VAP and in line plunger .40
Annex G (informative) Type of distribution of collected volume into laboratory bottle .42
Annex H (informative) Quality control of sampling equipment .43
Bibliography . 47

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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This document was prepared by Technical Committee ISO/TC 147, Water quality, SC 6, Sampling (general
methods).
This third edition cancels and replaces the second edition (ISO 5667-10:2020), which has been technically
revised. The main changes as follows:
[10]
— EN 16479 has been integrated in this document;
— microplastic sampling has been excluded from the scope.
A list of all parts in the ISO 5667 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
FINAL DRAFT International Standard ISO/FDIS 5667-10:2026(en)
Water quality — Sampling —
Part 10:
Waste water
1 Scope
This document specifies the sampling of urban and industrial waste water, i.e. the design of sampling
programmes and techniques for the collection of samples. This document covers waste water in all its forms,
i.e. industrial waste water, radioactive waste water, cooling water, raw and treated urban waste water.
This document deals with various sampling techniques used and the rules to be applied to ensure the
samples are representative.
This document does not cover sampling of accidental spillages, although the methods described in certain
cases can also be applicable to spillages.
This document is not applicable to sampling of microplastics in waste waters. Appropriate guidance is given
[1]
in ISO 5667-27 .
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and sampling
techniques
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 5667-7:1993, Water quality — Sampling — Part 7: Guidance on sampling of water and steam in boiler plants
ISO 5667-14:2014, Water quality — Sampling — Part 14: Guidance on quality assurance and quality control of
environmental water sampling and handling
ISO 5667-16, Water quality — Sampling — Part 16: Guidance on biotesting of samples
ISO 19458, Water quality — Sampling for microbiological analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

3.1
composite sample
two or more samples or sub-samples, mixed together in appropriately known proportions (either discretely
or continuously), from which the average value of a desired characteristic can be obtained
Note 1 to entry: The number of samples or sub samples are usually based on time, flow measurements, area or depth
profile sampling.
EXAMPLE Composite sample can be made in different ways:
— constant volume variable time sampling (CVVT): flow proportional sampling based on collecting equal
volumes of sample at frequencies proportional to flow.
— constant time variable volume sampling (CTVV): flow proportional sampling based on collecting samples
at fixed time intervals but where the volume of sample is varied in proportion to the flow.
— constant time constant volume sampling (CTCV): equal volumes of sample or sub-sample collected at
equal increments of time.
[2]
[SOURCE: ISO 6107:2021, 3.126 , modified — the EXAMPLE has been added.]
3.2
sampling point
precise position within a sampling site (3.3) from which samples are taken
[3]
[SOURCE: ISO 5667-12:2017, 3.8 ]
3.3
sampling site
general area or location from which samples are taken
[4]
[SOURCE: ISO 5667-6:2014, 3.10 ]
3.4
spot sample
discrete sample taken randomly (with regard to either time or location, or both) from a body of water,
usually taken manually, but can be taken by automatic sampling equipment or by event-triggered automatic
samplers
3.5
qualified spot sample
special form of a composite sample (3.1), consisting of at least five spot samples (3.4), taken and mixed within
a maximum period of two hours and at an interval of not less than two minutes
Note 1 to entry: In this definition, mixing signifies to carry out using either constant volume or variable volume,
in relation to the monitoring objective. The proportion in which spot sample need to be mixed should be clearly
mentioned.
3.6
radioactive liquid effluent
water or waste water that contains radioactive substances, resulting from a process and that can be either
recycled, treated or discharged to the environment, or all
Note 1 to entry: The activity concentration of the radioactive liquid effluent is usually measured before being
discharged in the environment to verify that it is lower than the authorized levels in order to comply with national
regulation.
3.7
supernatant
solid or liquid phase present on the surface of an effluent

3.8
planned discharge
discharge subject to prior agreement further to a consultation between several parties based on knowing
certain predefined parameters and referring to limit values (regulatory or otherwise)
Note 1 to entry: These parameters can be, for example, physical, chemical and radiological measurements, the
estimated discharge volume, the discharge period or the maximum discharge flow rate.
3.9
permanent discharge
direct discharge into a channel or collector or water body, which is not subject to a specific prior agreement,
but respects limit values
3.10
storage container
hollow object, very variable in size and shape, used to hold liquids
Note 1 to entry: Covers the usual names such as tank, lagoons and basins. The content of this storage container is
intended for direct and indirect liquid discharge to the environment or to a specific treatment.
3.11
event-triggered sampling
sampling which is triggered when a pre-determined criterion has been met (e.g. rainfall, change in electrical
conductivity, pH or the introduction of a polluting substance), when samples need to be taken manually or
by automatic equipment
3.12
bias
estimate of a systematic measurement error
Note 1 to entry: The systematic measurement error is a component of measurement error that in replicate
measurements remains constant or varies in a predictable manner.
[5]
[SOURCE: ISO/IEC Guide 99:2007, 2.18 , modified — Note 1 to entry has been added.]
3.13
measurement repeatability
repeatability
measurement precision under a set of repeatability conditions of measurement
Note 1 to entry: A repeatability condition of measurement is a condition of measurement, out of a set of conditions that
includes the same measurement procedure, same operators, same measuring system, same operating conditions and
same location, and replicate measurements on the same or similar objects over a short period of time
Note 2 to entry: A condition of measurement is a repeatability condition only with respect to a specified set of
repeatability conditions.
Note 3 to entry: In chemistry, the term “intra-serial precision condition of measurement” is sometimes used to
designate this concept.
[5]
[SOURCE: ISO/IEC Guide 99:2007, 2.21 , modified — Notes 1, 2 and 3 to entry has been added.]
3.14
representative sample
sample with the same quality and characteristics for the material of interest as that of its source at the time
of sampling
[6]
[SOURCE: ISO 2889:2023, 3.63 ]

4 General aspects
4.1 Design of sampling programme
Sampling is usually the first step in carrying out an investigation and largely determines the quality of the
whole investigation. It is therefore recommended that a detailed sampling strategy be drawn up, often based
upon a preliminary investigation in which an assessment has been carried out to identify the important
aspects. Both the purpose and the ambient situation determine the way in which the sampling is to be
carried out. General aspects for sampling programme design given in ISO 5667-1 shall be followed.
4.2 Sampling point selection — Representativeness
The selected sampling point should be appropriate for the collection of samples that are representative of
the waste of discharge to be examined. In some waste waters, this representativeness may be difficult to
obtain because of the spatial and temporal heterogeneity of the water body. It is necessary to carry out the
sampling in the sections where the flow is well mixed and homogeneous.
The term “representativeness” encompasses two notions depending on the type of environment to be
sampled:
— representativeness in a flow (canal, sewer, manhole, pressurized pipes, etc.);
— representativeness in a storage container (tank, lagoons, basins, etc.).
These two options should be treated in different ways, but the goal remains to obtain a representative
sample of the water body.
Sampling points can be clearly identified by regulatory text. If they are not, a preliminary investigation is
recommended. This is generally the case for the selection of sewer sampling locations. By first studying
technical drawings of the sewer system, potential sampling points should be identified. Subsequently,
a site inspection should be conducted to ensure that these sampling are representative. Each sampling
point should be documented. It is important to gather, for example, the following information: sampling
point identification, sampling site (photos, geographical coordinates), type of flow (open, closed), access
conditions and sampling technique.
The following facilities should be available for the sampling sites involving a fixed automatic sampling
device:
— access for suitable carrier to the immediate vicinity of the sampling site;
— flat working surfaces at appropriate height above the sampling point for the set-up of sampling devices;
— adequate lighting and power connection;
— water supply to clean the equipment after sampling;
— adequate safety precautions (e.g. grids, railings, fall arresting devices); and
— flow meters in the case of a flow-dependent sampling.
If the hydraulic conditions do not ensure the representativeness of the sample (e.g. absence of flow, reduced
activity, abnormal load rise), this unusual situation should be noted on the sampling report and the customer
and the analytical laboratory should be informed.
4.3 Frequency and time of sampling
4.3.1 Number of samples
The decision on the required number of samples taken during each period should be decided based on
[7] [8]
statistical techniques (see ISO 2602 , ISO 3534 (all parts) and ISO 5667-1). However, the number of
samples to be taken can often be decided by a regulatory body or pollution control authorities.

4.3.2 Sampling time for effluent stream
The objective of a sampling programme often dictates when and how a sample is collected and is often
determined by legislation or directives. Generally, when sampling sewages and effluents, it is normal to
make allowances for the following sources of variation in quality:
a) diurnal variations (i.e. within-day variability);
b) variations between days of the week;
c) variations between weeks and months;
d) variations between seasons;
e) variations due to storm water episodes;
f) trends; and
g) incident (general accident).
If there is little or no diurnal variation, or day-to-day variations, then the time of day or day of the week for
sampling is relatively unimportant.
If the identification of the nature and magnitude of peak load are important, sampling should be restricted
to those periods of the day, week or month when peak loads are known to occur.
When assessing industrial effluent discharges that are either seasonal or batch-based, it is recommended
that sampling times be aligned with the process being monitored. As the discharge will not be continuous in
either case, the sampling programme shall be taken this into account.
Sampling for the detection of trends needs careful planning. For example, when detecting trends on a
month-to-month basis, it can be appropriate to always sample on the same day of the week, in order that any
diurnal and daily variations are eliminated from the overall variability of data, thus allowing trends to be
more efficiently detected.
When the number of samples has been decided upon according to 4.3.1, the sampling times should be
determined. The samples should normally be taken at fixed intervals during the whole sampling period. The
sampling period may be one year, a number of months or weeks, or even shorter periods of time.
If the sampling period covers one year, the days of sampling may be determined using a formula. An example
of this is:
— Formula (1) should be applied when the number of samples (n), is equivalent or larger than 25 and
Formula (2) should be applied when number of samples is less than about 25.
— Formula (1) indicates the day number during which sampling should take place.
365 3652 3653 365n
A,,A A ,,A (1)
n n n n
where
n is the number of samples;
A is a random number in the interval between − and 0.
n
Formula (2) indicates the week number during which the sampling should take place. The day of each week
should be determined so that samples are taken on every weekday.

52 522523 52n
B,,B B ,,B (2)
n n n n
where
n is the number of samples;
B is a random number in the interval between − and 0.
n
Similar formulae can be used for other periods, for example, one month, three months, six months, etc. The
period chosen should cover any seasonal variations.
After determining the intervals and the day or week number, it should be ensured that the sampling does not
lead to any risk of systematic error, for example, by always taking samples on one day, or by systematically
omitting weekdays.
5 Sampling at specific locations
5.1 General
The concentration profiles of substances (hydrophilic and hydrophobic substances) to be measured in waste
waters are often heterogeneous because they depend on the hydraulic conditions and transport conditions
of the solid phase in the water body. The observations of concentration profile of these substances in body of
water may be as following:
— a vertical gradient of concentration, due to the flow velocities or the shear stresses near the bottom are
low;
— a very dense layer at the interface between the deposit of the bottom and the water circulating in the
structure;
— an increase of the concentration near the walls;
— an increase of the concentration near the surface of the flow due to the presence of floating matter.
To take a sample representative of the average concentration of the measured section, the sampling point
should be placed about halfway up the water column and at a sufficient distance from the walls and from
deposits at the bottom to avoid measurement bias.
5.2 Sampling from sewers, channels and manholes
The sampling point should be chosen where the effluent has a high turbulent flow to ensure good mixing
conditions. Difficult access, lack of security or power supply unavailable can preclude the selection of
alternative sampling points.
Sewers, channels and manholes are generally designed to cope with waste water or storm water discharge
conditions. In some cases, channels have to cope with combined effluent and storm water discharges. In the
absence of storm water discharge, this type of channel is oversized, resulting in laminar flow.
In the absence of turbulent flow conditions at a permanent sampling point, means for restricting the flow
should be implemented, for example using a baffle or weir. The restriction should be made in such a way
that sedimentation upstream does not occur (e.g. foresee enlargement of the downstream effluent channel
compared to the upstream channel, to avoid any pressure increase of the effluent downstream).
The sampling intake point should always be located downstream from the restriction and, as a general
rule, it should be located at least three times the pipe diameter, or width of the channel, downstream of
the restriction. The inlet of the sampling probe should preferably face the direction of flow but may face
downstream if too many blockages result.

The exact location of the sampling point should be evaluated with respect to variations in water level, types
and concentrations of the determinands, etc. The sampling point should be at a minimum distance from
the bottom and walls to avoid sample contamination by deposits or the biofilms that develop. Generally, a
sampling point between one third and one half of the effluent water depth below the surface of the water
may be recommended.
Whenever practicable, permanent sampling locations should be established, care being taken to ensure
reproducible sampling conditions.
Before proceeding with the sampling of industrial discharges and if the information is accessible, the
conditions inside the plant (e.g. processes and production rates) should be noted and recorded along with
any potential hazards.
5.3 Sampling from waste water treatment plant
When choosing sampling points for waste water treatment plant, it is again important to refer to the
objective of the data collection programme, of which the sampling is a part.
Typical objectives are:
— control of the performance of the entire treatment plant: samples should be collected at the main inlet
and main outlet points;
— control of the operation of individual processing units, or groups of units: samples should be collected at
the inlet and outlet of the units in question.
When sampling at the waste water treatment plant, the importance and the relevance of any bypass flow
should be evaluated. Sampling of such bypass flows may be needed for the sampling to be representative of
the overall effluent.
When sampling at the inlets of plants, there may be a need to sample raw sewage in the mixture with
recirculated processing liquid (e.g. in the assessment of primary sedimentation tank loadings and efficiency).
In other cases, it can be necessary to exclude the effect of these liquids (e.g. when collecting data designed to
assess either domestic or industrial loadings to a plant, or both, and to assist in industrial effluent control).
Representative sampling is often facilitated setting the sampling point downstream of a measuring flume or
weir (see also 5.2).
When sampling effluents from processes employing more than one individual treatment unit (e.g. several
sedimentation storage container), care should be exercised in ensuring that the sample is representative of
the overall effluent stream rather than any one specific treatment unit (unless that unit forms the basis of a
specific study).
Frequent reviews of a plant's sampling points need to be made to ensure that any relevant changes in the
operation of unit processes are considered when sampling. For example, the percolating filter operation may
be changed from a “single-pass” operation to a “recirculation” or “alternating-double filtration” operation.
Treatment plant operation may involve changes in the manner in which feed or return liquors are introduced
to the plant (e.g. return of sewage from storm tanks, changes in the position at which processing liquors are
returned to the treatment plant).
Whenever sampling waste waters, great care should be exercised to overcome or minimize the substantial
heterogeneity caused by suspended solids that are often present. Similarly, thermal stratification of separate
industrial effluent streams may be found when sampling effluents or discharges from industrial processes,
and measures have to be taken to promote the mixing of such streams before sampling.
5.4 Sampling from industrial sites
The sampling of industrial effluent can involve taking representative samples either before or after the
transfer of effluent to discharge channels or collectors. In some cases, samples may be taken both before and
after transfer.
The sampling method depends on the type of discharge or transfer taking place. The following should
therefore be distinguished:
— planned discharges, which require a preceding inspection before the discharge can take place: The
effluent in temporary storage containers, should meet the set requirements prior to being transferred to
general collectors or buffer pools for further discharge into the environment (refer to 7.4).
— permanent discharges, which concern effluents that are continuously discharged: They are monitored
based on sequential or continuous sampling of the discharged effluent. These may be, for example,
discharges from an effluent collector at the outlet of an industrial site prior to discharge into the
environment.
As such, the kind of sampling and the creation of representative samples shall be adapted to suit the type of
discharge and its potential heterogeneity (e.g. the presence of suspended matter or any density or thermal
stratification).
For this, and to guarantee the representative nature, the samples shall be produced:
— ensuring sampling only takes place after obtaining suitable effluent homogeneity;
— ensuring there is no change to the nature of the effluent or cross-contamination; and
— taking account of the volumes of the storage container, the flow rates and the flow conditions in the lines,
to enable quantification of the discharges from the facility in question (see Figure A.1 for an example of
sampling from storage containers).
Sampling may be performed based on several configurations, depending on the facilities:
— in a storage container prior to its discharge (see Figures A.1 and A.3);
— in a continuous or discontinuous flow in a line or a discharge channel (see Figure A.1).
5.5 Sampling from cooling systems
The selection of sampling points in industrial cooling processes using water as a coolant depends on the
cooling water system to be tested.
In continuous-flow cooling systems, fresh water (ground water, bank filtrate, surface water) or saline water
are used in one or repeated flow. The sampling points are located both in front and behind the aggregates,
which shall be cooled.
During cooling via the primary or secondary circuits, the two cooling circuits are coupled together. In this
process, the closed secondary circuit is cooled again by the primary circuit. The primary circuit can consist
of a continuous cooling system, an open or closed recooling plant or a refrigerating plant (e.g. brine cooling).
The sampling site should be on the return side and on a well through-flow site of the circulatory system.
In many cases, the cooling water is precooled in an open system by evaporation cooling, whereby water
losses due to evaporation, spraying and desludging (desalination) will be replaced by fresh water. In the
closed recooling process, the cooling water flows through pipes, which are cooled from outside by air or
water. The methods of open and closed recooling can be combined. The sampling site is located on the return
side of the circulatory system.
Representative sampling locations shall be defined throughout the system for periodic microbiological and
hygiene checks. Microbiological sampling guidance is given in ISO 19458. Samples are preferably taken
from the circulating water between the running pump and the spraying or trickling stage. A sampling
facility allowing disinfection (preferably by flaming) and draining shall be provided at this location. Before
sampling, sampling lines, connectors and taps should be sterilized (if possible) by autoclaving, by flaming or
if not possible, by cleaning with a disinfectant solution (refer to ISO 19458). Bottles and sampling equipment
should be clean and sterile, sterile both inside and out.

Allow the water to drain for at least 30 seconds before sampling. Sampling shall be performed in such a way
that the results are not distorted by biocide dosage. The sampling location shall be upstream of the biocide
dosage point.
If sampling is not possible at this location, a sample can be taken from the sprayed water or by bailing from
[9]
the circulating-water basin .
Special cooling processes are usually used when the medium to be cooled is very hot (e.g. waste heaters,
heat pumps) or when very low flow temperatures are required (e.g. brine cooling). For special cooling
processes in the high temperature range (i.e. temperature greater than 100 °C), the arrangements specified
in ISO 5667-7:1993, 6.4 and 6.5 shall be used.
6 Main types of waste waters sampling
6.1 Spot sampling
In the case of spot sampling (refer to Annex B), it is p
...

ISO/DISFDIS 5667-10
:2025(en) ISO/TC 147/SC 6/WG 14
Secretariat: BSI
Date: 2026-08-06
Water quality — Sampling — —
Part 10: Guidance on sampling waste
Waste water
Qualité de l'eau — Échantillonnage — Partie 10: Lignes directrices pour l'échantillonnage
des eaux résiduaires
Third edition Date:FDIS stage
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
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Internal
ISO/DIS 5667-10:2025(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of
this publication may be reproduced or utilized otherwise in any form or by any means, electronic or
mechanical, including photocopying, or posting on the internet or an intranet, without prior written
permission. Permission can be requested from either ISO at the address below or ISO's member body in the
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Published in Switzerland
iii
Contents Page
Foreword . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General aspects . 5
4.1 Design of sampling programme . 5
4.2 Sampling point selection — Representativeness . 5
4.3 Frequency and time of sampling . 6
5 Sampling at specific locations . 8
5.1 General . 8
5.2 Sampling from sewers, channels and manholes . 9
5.3 Sampling from waste water treatment plant. 9
5.4 Sampling from industrial sites . 10
5.5 Sampling from cooling systems . 11
6 Main types of waste waters sampling . 11
6.1 Spot sampling . 11
6.2 Composite sampling . 12
7 Waste water sampling . 12
7.1 General aspects . 12
7.2 Composite sampling for waste waters quality monitoring . 13
7.3 Spot sampling in an effluent stream . 21
7.4 Spot sampling of storage containers — Planned discharges . 23
8 Sampling equipment . 24
8.1 General . 24
8.2 Automatic sampler . 24
8.3 Manual sampling equipment . 25
8.4 Storage container sampling equipment . 26
9 Homogenization, preservation, transport and storage of samples . 27
9.1 Homogenization of collected volume . 27
9.2 Distribution of collected volume into laboratory bottles . 29
9.3 Preservation and packaging of samples . 29
9.4 Transportation and reception . 29
9.5 Security and traceability of samples during storage and delivery . 30
10 Quality assurance . 30
10.1 Risk of contamination . 30
10.2 Sample identification and records . 31
10.3 Assurance and quality control . 31
11 Reports . 32
11.1 Analytical reports . 32
11.2 Sampling protocols . 33
12 Safety precautions . 33
12.1 General . 33
12.2 Personnel safety . 33
12.3 Equipment safety . 34
Annex A (informative) Examples of sampling from storage containers . 36
iv
Annex B (informative) Advantages and disadvantages of main types of waste waters sampling . 1
Annex C (informative) Example of cleaning protocol — Sampling equipment . 34
Annex D (informative) Example of a field form — Waste waters sampling . 39
Annex E (informative) Choice of compatible materials for automatic samplers . 45
Annex F (informative) Comparison of pumping types: PP, VAP and in line plunger . 49
Annex G (informative) Type of distribution of collected volume into laboratory bottle . 52
Annex H (informative) Quality control of sampling equipment . 56
Bibliography . 67

v
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 147, Water quality, SC 6, Sampling (general
methods).
This third edition cancels and replaces the second edition (ISO 5667-10:2020), which has been technically
revised. The main changes as follows:
[10]
— EN 16479 has been integrated in this document;
— microplastic sampling has been excluded from the scope.
A list of all parts in the ISO 5667 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

vi
vii
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DRAFT International Standard ISO/DIS 5667-10:2025(en)

Water quality — Sampling — —
Part 10: Guidance on sampling waste
Waste water
1 Scope
This document specifies the sampling of urban and industrial waste water, i.e. the design of sampling
programmes and techniques for the collection of samples. This document covers waste water in all its forms, i.e.
industrial waste water, radioactive waste water, cooling water, raw and treated urban waste water.
This document deals with various sampling techniques used and the rules to be applied to ensure the samples
are representative.
This document does not cover sampling of accidental spillages, although the methods described in certain cases
can also be applicable to spillages.
This document is not applicable to sampling of microplastics in waste waters. Appropriate guidance is given in
[1][1]
ISO 5667-27 .
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references, the
latest edition of the referenced document (including any amendments) applies.
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and sampling
techniques
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 5667-7:1993, Water quality — Sampling — Part 7: Guidance on sampling of water and steam in boiler plants
ISO 5667-14:2014, Water quality — Sampling — Part 14: Guidance on quality assurance and quality control of
environmental water sampling and handling
ISO 5667-16, Water quality — Sampling — Part 16: Guidance on biotesting of samples
ISO 19458, Water quality — Sampling for microbiological analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
.
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ISO/DIS 5667-10:2025(en)
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/

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ISO/DIS 5667-10:2025(en)
3.33.1 3.1
composite sample
two or more samples or sub-samples, mixed together in appropriately known proportions (either discretely or
continuously), from which the average value of a desired characteristic maycan be obtained
Note 1 to entry: The number of samples or sub samples are usually based on time, flow measurements, area or depth profile
sampling.
EXAMPLE Composite sample can be made in different ways:
— constant volume variable time sampling (CVVT): flow proportional sampling based on collecting equal volumes of
sample at frequencies proportional to flow.
— constant time variable volume sampling (CTVV): flow proportional sampling based on collecting samples at fixed time
intervals but where the volume of sample is varied in proportion to the flow.
— constant time constant volume sampling (CTCV): equal volumes of sample or sub-sample collected at equal increments
of time.
[2]
[SOURCE: ISO 6107:2021, 3.126 ,, modified — the EXAMPLE has been added.] [2]
3.43.2 3.2
sampling point
precise position within a sampling site (3.3(3.3)) from which samples are taken
[3]
[SOURCE: ISO 5667-12:2017, 3.8 ] [3]]
3.53.3 3.3
sampling site
general area or location from which samples are taken
[4]
[SOURCE: ISO 5667-6:2014, 3.10 ] [4]]
3.63.4 3.4
spot sample
discrete sample taken randomly (with regard to either time and/or location, or both) from a body of water,
usually taken manually, but maycan be taken by automatic sampling equipment or by event-triggered automatic
samplers
3.73.5
3.7.1.1.1 3.5
qualified spot sample
special form of a composite sample (3.1(3.1),), consisting of at least five spot samples (3.4,), taken and mixed within
a maximum period of two hours and at an interval of not less than two minutes
Note 1 to entry: In this definition, mixing meanssignifies to carry out using either constant volume or variable volume, in
relation to the monitoring objective. The proportion in which spot sample need to be mixed should be clearly mentioned.

3.93.6 3.6
radioactive liquid effluent
water or waste water that contains radioactive substances, resulting from a process and that can be either
recycled, treated and/or discharged to the environment, or all

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ISO/DIS 5667-10:2025(en)
Note 1 to entry: The activity concentration of the radioactive liquid effluent is usually measured before being discharged in
the environment to verify that it is lower than the authorized levels in order to comply with national regulation.
3.103.7
3.10.1.1.1 3.7
supernatant
solid or liquid phase present on the surface of an effluent
3.113.8 3.8
planned discharge
discharge subject to prior agreement further to a consultation between several parties based on knowing certain
predefined parameters and referring to limit values (regulatory or otherwise)
Note 1 to entry: These parameters maycan be, for example, be physical, chemical and radiological measurements, the
estimated discharge volume, the discharge period or the maximum discharge flow rate.

3.133.9 3.9
permanent discharge
direct discharge into a channel or collector or water body, which is not subject to a specific prior agreement, but
respects limit values
3.143.10 3.10
storage container
hollow object, very variable in size and shape, used to hold liquids
Note 1 to entry: Covers the usual names such as tank, lagoons and basins. The content of this storage container is intended
for direct and indirect liquid discharge to the environment or to a specific treatment.
3.153.11
3.15.1.1.1 3.11
event-triggered sampling
sampling which is triggered when a pre-determined criterion has been met (e.g. rainfall, change in electrical
conductivity, pH or the introduction of a polluting substance), when samples need to be taken manually or by
automatic equipment
3.163.12 3.12
bias
estimate of a systematic measurement error
Note 1 to entry: The systematic measurement error is a component of measurement error that in replicate measurements
remains constant or varies in a predictable manner.
[5]
[SOURCE: ISO/IEC Guide 99:2007, 2.18 ,, modified — Note 1 to entry has been added.][5].]
3.173.13 3.13
measurement repeatability
repeatability
measurement precision under a set of repeatability conditions of measurement [SOURCE: ISO/IEC Guide
99:2007, 2.21][5]
3.17.1.1.1 3.14
Note 1 to entry: A repeatability condition of
measurement repeatability condition

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ISO/DIS 5667-10:2025(en)
is a condition of measurement, out of a set of conditions that includes the same measurement procedure, same operators,
same measuring system, same operating conditions and same location, and replicate measurements on the same or similar
objects over a short period of time
Note 1 2 to entry: A condition of measurement is a repeatability condition only with respect to a specified set of repeatability
conditions.
Note 2 3 to entry: In chemistry, the term “intra-serial precision condition of measurement” is sometimes used to designate
this concept.
[5]
[SOURCE: ISO/IEC Guide 99:2007, 2.21 20] [5], modified — Notes 1, 2 and 3 to entry has been added.]
3.183.14 3.15
representative sample
sample with the same quality and characteristics for the material of interest as that of its source at the time of
sampling
[6]
[SOURCE: ISO 2889:2023, 3.63 ] [6]]
4 General aspects
4.1 Design of sampling programme
Sampling is usually the first step in carrying out an investigation and largely determines the quality of the whole
investigation. It is therefore recommended that a detailed sampling strategy be drawn up, often based upon a
preliminary investigation in which an assessment has been carried out to identify the important aspects. Both
the purpose and the ambient situation determine the way in which the sampling is to be carried out. General
aspects for sampling programme design are given in ISO 5667-1 shall be followed.
4.2 Sampling point selection — Representativeness
The selected sampling point should be appropriate for the collection of samples that are representative of the
waste of discharge to be examined. In some waste waters, this representativeness may be difficult to obtain
because of the spatial and temporal heterogeneity of the water body. It is necessary to carry out the sampling in
the sections where the flow is well mixed and homogeneous.
The term “representativeness” encompasses two notions depending on the type of environment to be sampled:
sampled:
— representativeness in a flow (canal, sewer, manhole, pressurisedpressurized pipes, etc.);
— representativeness in a storage container (tank, lagoons, basins, etc.).
These two options should be treated in different ways, but the goal remains to obtain a representative sample of
the water body.
Sampling points maycan be clearly identified by regulatory text. If they are not, a preliminary investigation is
recommended. This is generally the case for the selection of sewer sampling locations. By first studying technical
drawings of the sewer system, potential sampling points should be identified. Subsequently, a site inspection
should be conducted to ensure that these sampling are representative. Each sampling point should be
documented. It is important to gather, for example, the following information: sampling point identification,
sampling site (photos, geographical coordinates), type of flow (open, closed), access conditions and sampling
technique.
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ISO/DIS 5667-10:2025(en)
The following facilities should be available for the sampling sites involving a fixed automatic sampling device:
— access for suitable carrier to the immediate vicinity of the sampling site;
— flat working surfaces at appropriate height above the sampling point for the set-up of sampling devices;
— adequate lighting and power connection;
— water supply to clean the equipment after sampling;
— adequate safety precautions (e.g. grids, railings, fall arresting devices); and
— flow meters in the case of a flow-dependent sampling.
If the hydraulic conditions do not ensure the representativeness of the sample (e.g. absence of flow, reduced
activity, abnormal load rise), this unusual situation should be noted on the sampling report and the customer and
the analytical laboratory should be informed.
4.3 Frequency and time of sampling
4.3.1 Number of samples
The decision on the required number of samples taken during each period should be decided based on statistical
[7][7] [8] [8]
techniques (see ISO 2602 ,, ISO 3534 (all parts) ) and ISO 5667-1). However, the number of samples to be
taken can often be decided by a regulatory body or pollution control authorities.
4.3.2 Sampling time for effluent stream
The objective of a sampling programme often dictates when and how a sample is collected and is often
determined by legislation or directives. Generally, when sampling sewages and effluents, it is normal to make
allowances for the following sources of variation in quality:
a) diurnal variations (i.e. within-day variability);
b) variations between days of the week;
c) variations between weeks and months;
d) variations between seasons;
e) variations due to storm water episodes;
f) trends; and
g) incident (general accident).
If there is little or no diurnal variation, or day-to-day variations, then the time of day or day of the week for
sampling is relatively unimportant.
If the identification of the nature and magnitude of peak load are important, sampling should be restricted to
those periods of the day, week or month when peak loads are known to occur.
Relating the sampling times to the process being monitored may be very important when consideringWhen
assessing industrial effluent discharges that are either seasonal or operated on a batch basis. In either case, the -
based, it is recommended that sampling times be aligned with the process being monitored. As the discharge will
not be continuous, and in either case, the sampling programme will need to takeshall be taken this fact into
account.
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ISO/DIS 5667-10:2025(en)
Sampling for the detection of trends needs careful planning. For example, when detecting trends on a month-to-
month basis, it can be appropriate to always sample on the same day of the week, in order that any diurnal and
daily variations are eliminated from the overall variability of data, thus allowing trends to be more efficiently
detected.
When the number of samples has been decided upon according to 4.3.14.3.1,, the sampling times should be
determined. The samples should normally be taken at fixed intervals during the whole sampling period. The
sampling period may be one year, a number of months or weeks, or even shorter periods of time.
If the sampling period covers one year, the days of sampling may be determined using a formula. An example of
this is:
— Formula
(1)(1) should be applied when the number of samples (n), is equivalent or larger than 25 and Formula
(2)(2) should be applied when number of samples is less than about 25.
— Formula
(1)(1) indicates the day number during which sampling should take place.
365 365×2 365×3 365× n
A + , A + , A + ,., A +
(1)
n n n n
365 365 × 2 365 × 3 365 ×𝑛𝑛
𝐴𝐴 + ,𝐴𝐴 + ,𝐴𝐴 + , … ,𝐴𝐴 +
𝑛𝑛 𝑛𝑛 𝑛𝑛 𝑛𝑛
(1)
where
−
n is the number of samples;
𝑛𝑛
and 0.
A
A is a random number in the interval
Formula (2)
between −
n
Formula (2) indicates the week number during which the sampling should take place. The day of each week
should be determined so that samples are taken on every weekday.
52 52×2 52×3 52× n
B + , B + , B + ,., B +
(2)
n n n n
52 52 × 2 52 × 3 52 ×𝑛𝑛
𝐵𝐵 + ,𝐵𝐵 + ,𝐵𝐵 + , … ,𝐵𝐵 +
𝑛𝑛 𝑛𝑛 𝑛𝑛 𝑛𝑛
(2)
where
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ISO/DIS 5667-10:2025(en)
n is the number of samples;
B is a random number in the interval between −
−
𝑛𝑛
and 0.
n
Similar formulae can be used for other periods, for example, one month, three months, six months, etc. The period
chosen should cover any seasonal variations.
After determining the intervals and the day or week number, it should be ensured that the sampling does not lead
to any risk of systematic error, for example, by always taking samples on one day, or by systematically omitting
weekdays.
5 Sampling at specific locations
5.1 General
The concentration profiles of substances (hydrophilic and hydrophobic substances) to be measured in waste
waters are often heterogeneous because they depend on the hydraulic conditions and transport conditions of the
solid phase in the water body. The observations of concentration profile of these substances in body of water may
be as following:
— Aa vertical gradient of concentration, due to the flow velocities or the shear stresses near the bottom are low;
— Aa very dense layer at the interface between the deposit of the bottom and the water circulating in the
structure;
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ISO/DIS 5667-10:2025(en)
— Anan increase of the concentration near the walls;
— Anan increase of the concentration near the surface of the flow due to the presence of floating matter.
To take a sample representative of the average concentration of the measured section, it is advisable to place the
sampling point should be placed about halfway up the water column and at a sufficient distance from the walls
and from deposits at the bottom to avoid measurement bias.
5.2 Sampling from sewers, channels and manholes
The sampling point should be chosen where the effluent has a high turbulent flow to ensure good mixing
conditions. Difficult access, lack of security, or power supply unavailable maycan preclude the selection of
alternative sampling points.
Sewers, channels and manholes are generally designed to cope with waste water or storm water discharge
conditions. In some cases, channels have to cope with combined effluent and storm water discharges. In the
absence of storm water discharge, this type of channel is oversized, resulting in laminar flow.
In the absence of turbulent flow conditions at a permanent sampling point, means for restricting the flow should
be implemented, for example using a baffle or weir. The restriction should be made in such a way that
sedimentation upstream does not occur (e.g. foresee enlargement of the downstream effluent channel compared
to the upstream channel, to avoid any pressure increase of the effluent downstream).
The sampling intake point should always be located downstream from the restriction and, as a general rule, it
should be located at least three times the pipe diameter, or width of the channel, downstream of the restriction.
The inlet of the sampling probe should preferably face the direction of flow but may face downstream if too many
blockages result.
The exact location of the sampling point should be evaluated with respect to variations in water level, types and
concentrations of the determinands, etc. The sampling point should be at a minimum distance from the bottom
and walls to avoid sample contamination by deposits or the biofilms that develop. Generally, a sampling point
between one third and one half of the effluent water depth below the surface of the water may be recommended.
Whenever practicable, permanent sampling locations should be established, care being taken to ensure
reproducible sampling conditions.
Before proceeding with the sampling of industrial discharges and if the information is accessible, the conditions
inside the plant (e.g. processes and production rates) should be noted and recorded along with any potential
hazards.
5.3 Sampling from waste water treatment plant
When choosing sampling points for waste water treatment plant, it is again important to refer to the objective of
the data collection programme, of which the sampling is a part.
Typical objectives are:
— control of the performance of the entire treatment plant: samples should be collected at the main inlet and
main outlet points;
— control of the operation of individual processing units, or groups of units: samples should be collected at the
inlet and outlet of the units in question.

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When sampling at the waste water treatment plant, the importance and the relevance of any bypass flow should
be evaluated. Sampling of such bypass flows may be needed for the sampling to be representative of the overall
effluent.
When sampling at the inlets of plants, there may be a need to sample raw sewage in the mixture with recirculated
processing liquid (e.g. in the assessment of primary sedimentation tank loadings and efficiency).
In other cases, it maycan be necessary to exclude the effect of these liquids (e.g. when collecting data designed to
assess either domestic or industrial loadings to a plant, or both, and to assist in industrial effluent control).
Representative sampling is often facilitated setting the sampling point downstream of a measuring flume or weir
(see also 5.25.2).).
When sampling effluents from processes employing more than one individual treatment unit (e.g. several
sedimentation storage container), care should be exercised in ensuring that the sample is representative of the
overall effluent stream rather than any one specific treatment unit (unless that unit forms the basis of a specific
study).
Frequent reviews of a plant's sampling points need to be made to ensure that any relevant changes in the
operation of unit processes are considered when sampling. For example, the percolating filter operation may be
changed from a "“single-pass"” operation to a "“recirculation"” or "“alternating-double filtration"” operation.
Treatment plant operation may involve changes in the manner in which feed or return liquors are introduced to
the plant (e.g. return of sewage from storm tanks, changes in the position at which processing liquors are returned
to the treatment plant).
Whenever sampling waste waters, great care should be exercised to overcome or minimize the substantial
heterogeneity caused by suspended solids that are often present. Similarly, thermal stratification of separate
industrial effluent streams may be found when sampling effluents or discharges from industrial processes, and
measures have to be taken to promote the mixing of such streams before sampling.
5.4 Sampling from industrial sites
The sampling of industrial effluent can involve taking representative samples either before or after the transfer
of effluent to discharge channels or collectors. In some cases, samples may be taken both before and after transfer.
The sampling method depends on the type of discharge or transfer taking place. The following should therefore
be distinguished:
— planned discharges, which require a preceding inspection before the discharge can take place.: The effluent
in temporary storage containers, should meet the set requirements prior to being transferred to general
collectors or buffer pools for further discharge into the environment (refer to 7.47.4);).
— permanent discharges, which concern effluents that are continuously discharged.: They are monitored based
on sequential or continuous sampling of the discharged effluent. These may be, for example, discharges from
an effluent collector at the outlet of an industrial site prior to discharge into the environment.
As such, the kind of sampling and the creation of representative samples shall be adapted to suit the type of
discharge and its potential heterogeneity (e.g. the presence of suspended matter or any density or thermal
stratification).
For this, and to guarantee the representative nature, the samples shall be produced:
— ensuring sampling only takes place after obtaining suitable effluent homogeneity;
— ensuring there is no change to the nature of the effluent or cross-contamination; and

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ISO/DIS 5667-10:2025(en)
— taking account of the volumes of the storage container, the flow rates and the flow conditions in the lines, to
enable quantification of the discharges from the facility in question (see Figure A.1Figure A.1 for an example
of sampling from storage containers).
Sampling may be performed based on several configurations, depending on the facilities:
— in a storage container prior to its discharge (see Figures A.1Figures A.1 and A.3A.3););
— in a continuous or discontinuous flow in a line or a discharge channel (see Figure A.1Figure A.1).).
5.5 Sampling from cooling systems
The selection of sampling points in industrial cooling processes using water as a coolant depends on the cooling
water system to be tested.
In continuous-flow cooling systems, fresh water (ground water, bank filtrate, surface water) or saline water are
used in one or repeated flow. The sampling points are located both in front and behind the aggregates, which
shall be cooled.
During cooling via the primary or secondary circuits, the two cooling circuits are coupled together. In this process,
the closed secondary circuit is cooled again by the primary circuit. The primary circuit can consist of a continuous
cooling system, an open or closed recooling plant or a refrigerating plant (e.g. brine cooling). The sampling site
should be on the return side and on a well through-flow site of the circulatory system.
In many cases, the cooling water is precooled in an open system by evaporation cooling, whereby water losses
due to evaporation, spraying and desludging (desalination) will be replaced by fresh water. In the closed
recooling process, the cooling water flows through pipes, which are cooled from outside by air or water. The
methods of open and closed recooling can be combined. The sampling site is located on the return side of the
circulatory system.
Representative sampling locations shall be defined throughout the system for periodic microbiological and
hygiene checks. Microbiological sampling guidance is given in ISO 19458. Samples are preferably taken from the
circulating water between the running pump and the spraying or trickling stage. A sampling facility allowing
disinfection (preferably by flaming) and draining is toshall be provided at this location. Before sampling, sampling
lines, connectors and taps should be sterilized (if possible) by autoclaving, by flaming or if not possible, by
cleaning with a disinfectant solution (refer to ISO 19458). Bottles and sampling equipment should be clean and
sterile, sterile both inside and out.
Allow the water to drain for at least 30 seconds before sampling. Sampling shall be performed in such a way that
the results are not distorted by biocide dosage. The sampling location shall be upstream of the biocide dosage
point.
If sampling is not possible at this location, a sample can be taken from the sprayed water or by bailing from the
[9] [9]
circulating-water basin .
Special cooling processes are usually used when the medium to be cooled is very hot (e.g. waste heaters, heat
pumps) or when very low flow temperatures are required (e.g. brine cooling). For special cooling processes in
the high temperature range (i.e. temperature greater than 100 °C), the arrangements specified at 6.4 and 6.5 in
ISO 5667-7:1993, 6.4 and 6.5 shall be used.
6 Main types of waste waters sampling
6.1 Spot sampling
In the case of spot sampling (refer to Annex BAnnex B),), it is possible to implement:
a) direct sampling in waste waters:

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ISO/DIS 5667-10:2025(en)
1) directly by using laboratory bottles;
2) by using a ballasted sample collector equipped with laboratory bottles;
3) by using an automatic sampler.
b) indirect sampling in waste waters:
1) by using a sampling rod equipped with a collection container;
2) by using a bucket or other equipment.
NOTE Spot samples are usually taken manually but can be taken by automatic sampling equipment or by event-
triggered automatic samplers.
6.2 Composite sampling
Composite sampling consists of collecting several discrete samples and combining them into a single (composite)
sample. It can be done automatically or manually (see 3.13.1, Figure A.2, Figure A.2 and Annex BAnnex B).).
There are several ways of performing composite sampling:
— constant volume variable time sampling (CVVT);;
— constant time variable volume sampling (CTVV);;
— constant time constant volume sampling (CTCV).
For manual composite sampling, this approach is equivalent to sampling with fixed time, fixed flow and fixed
volume.
7 Waste water sampling
7.1 General aspects
7.1.1 General
The purpose of the sampling should clearly be defined so that the sampler may implement the appropriate
sampling strategy.
7.1.17.1.2 Preparation of the sampling campaign
Controlled sampling is conditioned by good preparation of the sampling campaign and knowledge of the activity
of the establishment, type and mode of operation.
The sampler should take all necessary steps to ensure that the coordinates and the feasibility of the operations
requested are established beforehand. The use of a GPS and the exploitation of the photos or plans available, or
the observations collected during the preliminary investigation make it possible to avoid any localization errors.
The procedures relating to sampling operations and measurements, as well as the notices specific to in- situ
measurement apparatus (pH meter, conductivity, etc.) shall be available.
All equipment (in -situ measurement apparatus, sampling equipment, refrigerated device) should be
metrologically checked. Use dedicated equipment for waste waters sampling.
Laboratory bottles should be selected and prepared according to the type of analysis requested and respecting
the packaging and preservation conditions prescribed by the laboratory.

Internal
ISO/DIS 5667-10:2025(en)
Recordings of sampling operations (e.g. field form, label, other) should be prepared and possibly pre-filled.
Ensure the safety conditions (see Clause 12Clause 12)) before any intervention.
7.1.27.1.3 Arrival on site
It is important to confirm on site, theThe location of the points where the sampling operation will be carried out.
In case of pollution identification, consider the extent of pollution shall be confirmed onsite.
It is recommended that theThe sample should be taken out below the surface of the water in order to avoid
contamination from floating materials. Avoid manipulations of the samples, such as transfer or shaking, to a
minimum to prevent any changes. The total sample volume depends on the study programme and the extent of
the analysis and can vary widely, from a few millilitres to many litres.
As a rule, floating and sedimented materials cannot be sampled representatively out of flowing water. The
quantity and the substances present in these materials can be determined by sampling them separately.
When sampling out of sewers using ladles, care should be taken that the scoop is moved in the direction of flow
under the surface of the water at a rate adapted to the flow. The opening of the scoop is in the flow direction.
To avoid contamination of the sample, make sure that the scoop does not touch the wall of the sampling manhole
or the bottom of the sewer.
In many cases, pipes specially designed for sampling with a small nominal width, which either have a continuous
flow of waste waters or cooling water (by-pass line) or with a shut-off device (sampling device) are used. It is
recommended to change to samples using vertical pipes in turbulent flow. When laying the sampling lines, longer
horizontal pipe sections should be avoided. The length of the sampling lines should be at least five times the pipe
diameter from the manifold to ensure a sampling in the fully mixed zone.
7.2 Composite sampling for waste waters quality monitoring
7.2.1 General
The objective is to collect a representative sample of a water body over a period of time, ranging from a few hours
to a day or a week.
For selecting the sampling period over which a composite sample has to be taken, two factors should be
considered:
a) Thethe objective of the sampling. For example, it may;
EXAMPLE It can be necessary to assess the average organic load in a flow over several 24 h periods, in which case flow
proportional composite samples will beare adequate.
b) Thethe stability of the sample. In; in the example given in a), it wouldis not necessarily bealways practical to
extend the compositing period for longer than 24 h, since the organic component in the sample under study
maycan deteriorate.
The overall sampling period maycan vary from a few hours, wherewhen tracing studies on volatile organics are
being monitored, to several days, wherewhen stable inorg
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