SIST EN 25667-1:1996

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wasserbeschaffenheit - Probenahme - Teil 1: Anleitung zur Aufstellung von Probenahmeprogrammen (ISO 5667-1:1980)Qualité de l'eau - Echantillonnage - Partie 1: Guide général pour l'établissement des programmes d'échantillonnage (ISO 5667-1:1980)Water quality - Sampling - Part 1: Guidance on the design of sampling programmes (ISO 5667-1:1980)13.060.45Preiskava vode na splošnoExamination of water in generalICS:Ta slovenski standard je istoveten z:EN 25667-1:1993SIST EN 25667-1:1996en01-september-1996SIST EN 25667-1:1996SLOVENSKI
STANDARD



SIST EN 25667-1:1996



SIST EN 25667-1:1996



SIST EN 25667-1:1996



SIST EN 25667-1:1996



SIST EN 25667-1:1996



International Standard 566711 INTERNATIONAL ORGANIZATION FOR STANDARDIZATlONWVlE~YHAPO~HAR OPTAHM3AlJMR fl0 CTAH~APTbl3ALWWORGANlSATlON INTERNATIONALE DE fiORMALISATION Water quality - Sampling - Part 1 : Guidance on the design of sampling programmes Qua/it& de l’eau - khan tillonnage - Partie I : Guide g&n&al pour IWablissemen t des programmes d’khan tilonnage First edition - 1980-09-15 UDC 614.777 : 620.113 Ref. No. IS0 5667/l-1980 (E) Descriptors : water, quality, sampling, sampling equipment, generalities. Price based on 13 pages SIST EN 25667-1:1996



Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing Inter- national Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been set up 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 5667/l was developed by Technical Committee ISO/TC 147, Water quality, and was circulated to the member bodies in June 1978. It has been approved by the member bodies of the following countries : Australia Austria Brazil Bulgaria Canada Czechoslovakia Denmark France Germany, F. R. Greece Hungary The member body technical grounds of the following country expressed disapproval of the docu ment on India Ireland Italy Japan Korea, Rep. of Mexico Netherlands New Zealand Norway Poland Romania Belgium South Africa, Rep. of Spain Sweden Switzerland Thailand United Kingdom USA USSR Yugoslavia 0 International Organization for Standardization, 1980 Printed in Switzerland ii SIST EN 25667-1:1996



. Contents Page 0 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Scope and field of application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 References. 1 Section one : Definition of objectives 3 Introduction. . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5 Special considerations in relation to variability . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Section two : Identification of sampling situations 6 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 General safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . 4 8 Special considerations in sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 9 Individual sampling situations - Natural waters . 5 10 Sampling situations in industry. . 7 11 Tradeeffluents . 8 12 Sewage and sewage effluents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 13 Storm sewage and surface run-off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Section three : Time and frequency of sampling 14 lntroduction. 10 15 Types of sampling programme . 10 16 Statistical considerations . 10 17 Abnormal variability . 11 18 Duration of sampling occasion and composite samples . . . . . . . . . . . . . . . . . . . 11 Section four : Flow measurements and situations justifying flow measurements for water quality purposes 19 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 20 Justification for flow measurements in water quality control . . . . . . . . . . . . . . l 12 21 Methods available for flow measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 . . . III SIST EN 25667-1:1996



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INTERNATIONAL STANDARD IS0 5667/l-1980 (E) Water quality - Sampling - Part 1 I Guidance on the design of sampling programmes 0 Introduction This International Standard is the first of a group of three stan- dards intended to be used in conjunction with each other. IS0 5667/2 and IS0 5667/3 deal respectively with sampling techniques and with the preservation and handling of samples. The general terminology used is in accordance with that established in ISO/TC 147, Water quality, and, more particu- larly, with the terminology on sampling given in IS0 6107/2. 1 Scope and field of application This International Standard sets out the general principles to be applied in the design of sampling programmes for the purposes of quality control, quality characterization, and identification of sources of pollution of water, including bottom deposits and sludges. Detailed instructions for specific sampling situations will be given in subsequent International Standards. 2 References IS0 2662, Statistical interpretation of test results - Estimation of the mean - Confidence interval. IS0 3534, Statistics - Vocabulary and symbols. IS0 566712, Water quality - Sampling - Part 2 : General guidelines to sampling techniques. 1) IS0 566713, Water quality - Sampling - Part 3 : General recommendations for the preservation and handling of samples. 1) IS0 610711, Water quality - Vocabulary - Part 7. IS0 610712, Water quality - Vocabulary - Part 2.1) 1) At present at the stage of draft. 1 SIST EN 25667-1:1996



IS0 5667/l-1980 (E) Section one : Definition of objectives 3 Introduction The purpose of this section is to emphasise the more important factors which have to be considered when devising a sampling programme in relation to water, bottom deposits and sludges. More detailed information is given in subsequent sections. Samples are collected and examined primarily to determine associated physical, chemical, biological and radiological parameters. Whenever a volume of water, bottom deposit or sludge is to be characterized, it is generally impossible to examine the whole and it is therefore necessary to take samples. The samples col- lected should be as fully representative as possible of the whole to be characterized, and all precautions should be taken to en- sure that, as far as possible, the samples do not undergo any changes in the interval between sampling and analysis. The sampling of multiphase systems, such as water containing suspended solids or immiscible organic liquids, can present special problems. Before any sampling programme is devised, it is very important that the objectives be established since they are the major fac- tors in determining the position of sampling sites, frequency of sampling, duration of sampling, sampling procedures, sub- sequent treatment of samples, and analytical requirements. Some consideration should also be given to the degree of detail and precision that will be adequate, and also the manner in which the results are to be expressed and presented, for exam- ple concentrations or loads, maximum and minimum values, arithmetic means, median values etc. Additionally, a list of parameters of interest should be compiled and the relevant analytical procedures consulted since these will usually give guidance on precautions to be observed during sampling and subsequent handling. (General guidance on the latter aspects is given in Parts 2 and 3 of this International Standard respect- ively . ) It may often be necessary to carry out a preliminary sampling and analysis programme before the final objectives can be defined. It is important to take into account all relevant data from previous programmes at the same or similar locations and other information on local conditions. Previous personal ex- perience can also be very valuable. Time and money allocated to the design of a proper sampling programme is usually well justified by ensuring that the required information is obtained efficiently and economically. Three main objectives may be distinguished as follows (for details, see clause 15) : a) quality control measurements used by local manage- ment to decide when short-term process corrections are re- quired; b) quality characterization measurements used to indicate quality, perhaps as part of a research project, for long-term control purposes, or to indicate long-term trends; c) identification of sources of pollution. The purpose of the programme may change from quality characterization to quality control and vice-versa. For example, 2 a longer term programme for nitrate characterization may become a short-term quality control programme requiring increased frequency of sampling as the nitrate concentration approaches a critical value. 4 Requirements Without attempting to list all the specific reasons for requiring sampling and analysis programmes, they may be grouped as follows. 4.1 General requirements To establish the order of concentration levels or loads of specific parameters at selected positions (for example at the surface of, or in, a body of water) or, with bottom deposits, to obtain a visual indication of their nature. ’ 4.2 Specific requirements To establish in detail the concentration levels or load distri- butions of physical or chemical parameters and biological species of interest throughout the whole or part of a body of water. This will normally be linked to a study of changes with time, flow rates, operating plant conditions, weather condi- tions etc. These reasons for sampling may be further sub-divided into more specific objectives such as the following. a! To determine the suitability of water for an intended use and, if necessary, to assess any treatment or controt re- quirements, for example to examine borehole water for cooling, boiler feed or process purposes, or, if a natural spring, as a possible source of drinking water. b) To study the effect of waste discharges, including accidental spillages, on a receiving water. Apart from contributing to the pollution load, such discharges may pro- duce other reactions such as chemical precipitation or evolution of gases. c) To assess the performance and control of water, sewage and industrial effluent plants - for example : to assess the variations and long-term changes in load entering a treatment works; to determine the efficiency of each stage in a treatment process; to provide evidence of quality of treated water; to control the concentration of treated substances including those which may constitute a health hazard or which may inhibit a bacteriological process; to control substances which may damage the fabric of plant or equipment. d) To study the effects of fresh and saline water flows on estuarine conditions in order to provide information on mix- ing patterns and associated stratification with variations in tides and freshwater flow. e) To identify and quantify products lost from industrial processes. This information is required when product SIST EN 25667-1:1996



IS0 5667/l-1980 E) balances across the plant are to be assessed and when effluent discharges are to be measured. f) To establish the quality of boiler water, steam conden- sate and other reclaimed water. This enables the suitability of the water for an intended purpose to be assessed, g) TO control the operation of industrial cooling water systems. This enables the use of water to be optimized and, at the same time, the problems associated with scale forma- tion and corrosion to be minimized. On some occasions the conditions may be sufficiently stable for the required information to be obtained from a simple sampling programme, but in most locations quality characteristics are subject to continuous variations and, ideally, assessment should also be continuous. However, this is often very costly and in many situations impossible to achieve. When consider- ing sampling programmes, the special considerations given in clause 5 should be borne in mind. 5 Special considerations in relation to variability h) To study the effects of atmospheric pollutants on the quality of rainwater. This provides useful information on air quality and also indicates if problems are likely to arise, for example, on exposed electrical contacts. j) To assess the effect of inputs from the land on water quality. There may be contributions from naturally occur- ring materials, or contamination by fertilizers, pesticides and chemicals used in agriculture, or both. 5.1 Sampling programmes may be complex in situations where wide and rapid variations occur in the concentrations of determinands of interest. These variations may be caused by such factors as extreme changes in temperature, flow patterns or plant operating conditions. Sampling should be avoided at or near boundaries of systems unless conditions are of special interest. k) To assess the effect of the accumulation and release of substances by bottom deposits on the aquatic biota in the water mass or bottom deposit. 5.2 Even when concentration changes are slow and not very marked, the assessment of a large catchment area, such as a river basin, is a complex exercise. n) To assess changes in water quality which occur in 5.4 Composite samples give the best indication of the distribution systems. These changes can occur for a average composition over a period of time provided that the number of reasons, for example contamination, introduc- determinand is stable during the period between sampling and tion of water from a new source, biological growths, examination, but they are of little value in determining transient deposition of scale or dissolution of metal. peak conditions. SIST EN 25667-1:1996



IS0 5667/l-1980 (E) Section two : Identification of sampling situations 6 Introduction This section deals with the various situations that may be en- countered in sampling practice and the extent to which these situations affect the choice of a sampling site. Attention is drawn to the safety precautions necessary in various situations which, in view of their importance and general character, are set out in clause 7. 7 General safety precautions 7.1 The enormously wide range of conditions encountered in sampling waters and bottom deposits can subject personnel to a variety of safety and health risks. Apart from physical injury, precautions must be taken to avoid inhalation of toxic gases and ingestion of toxic materials through the mouth and skin. Personnel responsible for the design of sampling programmes and for carrying out sampling operations must ensure that the requirements of relevant safety regulations are taken into ac- count and that sampling personnel are informed of the necessary precautions to be taken in sampling operations. NOTE - Insurance against accidents may need to be considered. More specific situations are discussed below. 7.2 Weather conditions should be considered in order to en- sure the safety of personnel and equipment. Life-jackets and life-lines should be worn when sampling large masses of water. Before sampling from ice-covered waters, the location and ex- tent of weak ice should be carefully checked. If self-contained underwater breathing apparatus or other diving equipment is used, it should always be checked and maintained to ensure reliability. 7.3 Stability is an important property of any boat used for sampling purposes. In all waters, precautions should be taken in relation to commercial ships and fishing vessels; for example, the correct signal flags should be flown, to indicate the nature of the work being undertaken. 7.4 Sampling from unsafe sites, such as unsafe banks, should be avoided if possible. If this is unavoidable, the operation should be conducted by a team using appropriate precautions rather than one operator. Sampling from bridges should be used when appropriate. 7.5 Reasonable access in all weather is important and it is essential for frequent routine sampling. In some situations, consideration should be given to additional natural hazards such as poisonous foliage, animals and reptiles. 7.6 If instruments or other items of equipment are installed on a river bank, situations susceptible to flooding or vandalism should be avoided, or appropriate precautions taken. 7.7 Many other situations arise during the sampling of water when special precautions have to be taken to avoid accidents. 4 For example, some industrial effluents may be corrosive or may contain toxic or flammable materials. The dangers associated with sewage should also not be overlooked; these may be gaseous, microbiological, virological or zoological, such as from amoebae or helminths. 7.8 Gas protection equipment, breathing apparatus, resuscitation apparatus and other safety equipment should be available when personnel have to enter hazardous atmospheres. In addition, the concentration of oxygen and of any toxic vapour or gas likely to be present should be measured before personnel enter enclosed spaces. 7.9 In the sampling of steam and hot discha ws, special care is necessary and recognised techn ques shou Id be applied. 7.10 The handling of radioactive samples requi res special care and the special techniques required should be applied. 7.11 The use of electrically operated sampling equipment in or near water can present special electrocution hazards. Work procedures, site design and equipment maintenance should be planned so as to minimize these hazards. 8 Special considerations in sampling 8.1 Design of sampling programmes Depending on the objectives to be achieved (see clause 61, the sampling network may be anything from a single site to an en- tire river catchment. A basic river network may comprise sampling sites at the tidal limit, major tributaries at their con- fluence, and major discharges of sewage or industrial effluent. In designing quality sampling networks it is usual to make pro- vision for the measurement of flow at key stations (see section 4). 8.2 Identifying the sampling location Identifying the sampling location enables comparative samples to be taken at other times. In most river situations, sampling locations can readily be fixed by reference to features on the river bank. On uncovered estuarine and coastal shores, sampling locations may similarly be related to an easily recognizable static object. For sampling from a boat in these situations, instrumental methods for location identification should be used. Map references or other standard forms of reference may be valuable. 8.3 Character of flow Ideally, samples should be taken from turbulent, well-mixed liquids and, whenever possible, turbulence should be induced in flows that are streamlined. This does not apply to the collec- SIST EN 25667-1:1996



IS0 5667/l-1980 (El tion of samples for the determination of dissolved gases and volatile materials, the concentration of which may be altered by induced turbulence. 84 . Change in flow characteristics with time Flow may change from streamlined to turbulent and vice-versa. “Reverse flow” from other parts of the system may occur which could produce contamination at the sampling point. 8.11 Mixtures of waters of different densities These can cause layering in a streamlined flow, for example the production of a layer of warm water over cold water or of fresh water over saline water. -r ‘1s 8.12 Hazardous liquids It is necessary to consider the possibility of the presence of toxic liquids or fumes, or both, and the possible build-up of explosive vapours. 8.5 Change of liquid composition with time 8.13 Effect of meteorological conditions Discrete “slugs” of material may occur at any time, for exam- ple, dissolved contaminants, solids, volatile materials or oily surface layers. 8.6 Sampling from pipes Liquids should be pumped through pipes of adequate size (for example, when sampling heterogeneous liquids, of minimum nominal bore 25 mm) at linear velocities high enough to main- tain turbulent flow characteristics. Horizontal pipe runs should be avoided. 8.7 Nature of the liquid The liquid may be corrosive or abrasive. Resistance to these conditions should be considered. It should be borne in mind that the cheapest course is not necessarily to use expensive chemically-resistant equipment for short-term sampling if the equipment can readily be replaced and contamination of the sample by corrosion products is not likely to be important. 8.8 Temperature changes systems occurring in sampling Temperature variation over long or short periods may cause changes in the nature of the sample that may affect the equip- ment used for sampling. 8.9 Sampling for determination of suspended solids Solids may be distributed anywhere throughout the depth of a liquid. Adequate mixing should be carried out, if possible, by maintaining turbulent conditions. Ideally, the linear velocity should be sufficient to induce turbulence and samples should be taken under isokinetic conditions (see IS0 6107/2). If this is not possible, a series of samples should be taken across a full cross-section of the flow. It should be remembered that the size distribution of suspended solids may change during the time necessary to complete the sampling. Changes in meteorological conditions may induce marked variations in water quality; such changes should be noted and allowance made for them when interpreting results. 9 Individual sampling situations - Natural waters 9.1 Precipitation When samples of precipitation are collected for chemical analysis, the sampling site should be selected to avoid con- tamination by extraneous matter, for example dust, fertilizers, pesticides, etc. The sampling apparatus should preferably be placed in a lawn. If the sample is frozen or consists of snow or hail, the funnel should preferably be kept warm by, for example, an electric heating element. Where this is not possible, the entire ap- paratus should be removed and thawed at low temperatures. 9.2 Estuaries, coastal waters, seas and oceans 9.2.1 Extent and depth The boundaries of the area under investigation should be clearly defined and consideration given to the relation of the area to adjacent areas of water. Selection of sampling sites and positions should take into account the fact that tidal currents and their modification by wind, density, bottom roughness, shore line proximity and shipping can all produce considerable disturbance within the water and variation in water quality at the designated sampling site. In addition, the effect upon sampling of any local discharges should be carefully con- sidered. 9.2.2 Use of boats Boats, when used, should be capable of reaching all sampling positions within the time-limits of the survey in suitable weather conditions. 8.10 Sampling for volatile compounds content 9.2.3 Ice cover Material being sampled should be pumped with minimum suction lift. All pipework should be kept full and the sample bled from a pressurized pipe after running some of the material to waste to ensure that the sample collected is representative. In water under ice cover, a restricted inverse thermal stratifica- tion develops with a thin layer (about 5 mm) of cold water at 0 to 3 OC on top of the main mass of water at 4 OC. Steep 5 SIST EN 25667-1:1996



IS0 5667/l-1980 (E) thermal concentration gradients may be associated with this thermal stratification and biological communities may also be stratified. In large water necessary. masses, sampling from a boat is normally 9.6 Groundwaters 9.3 Rivers and streams 9.6.1 Abstracted groundwater 9.3.1 Mixing If significant streaming or stratification exists at the sampling point, a series of transverse and depth samples should be col- lected to determine the nature and extent of any streaming or stratification. Samples are required to assess the suitability of an abstracted groundwater for a particular use. Samples may be taken at the abstraction point, although these samples may not be repre- sentative of the general quality of the water in the aquifer. 9.6.2 Water in an aquifer 9.3.2 Selection of sites Sites should be selected so as to provide representative samples, preferably where marked quality changes are likely to occur or where there are important river uses, for example con- fluences, major discharges or abstractions. Weirs or small discharges which are only very local in effect should generally be avoided. Sites should preferably be chosen where flow data are available. River gauging huts are frequently used for the installation of water-monitoring equipment. If sampling is intended to monitor the effects of a discharge, sampling both upstream and downstream should be carried out, but careful consideration should be given to the mixing of the discharge and receiving water and its effects on the downstream samples. Sampling should extend for an appropriate distance downstream to assess the effects on the river. 9.4 Canals In general, the considerations for rivers and the following factors need special attention 9.4.1 Flow streams apply , but The direction of flow may be changeable. The flow rate may vary considerably and be more dependent upon the amount of navigational use (i.e. the number of locking operations) than upon prevailing weather conditions. 9.4.2 Stratification and streaming These will tend to be more pronounced than in rivers under the quiescent conditions found in canals. The passage of boats may have a very marked short-term effect on the quality of water in a canal, especially on the suspended solids concentra- tion. 95 . Storage reservoirs and lakes Sampling should be carried out at all available draw-off points and draw-off depths in addition to inputs. The water body may be thermally stratified and very significant quality differences may develop between different depths. Ecological investiga- tions may require a more detailed sampling programme; flow data and meteorological data may be required. When sampling is carried out to assess the quality of water in an aquifer, the well or borehole should, whenever possible, be pumped prior to sampling to ensure that new water is drawn from the aquifer. Even in these circumstances, the water in the well or borehole may be stratified and additional sampling may be required to assess the degree of stratification. The depth below ground level at which the sample is taken should always be recorded. Wells or boreholes lined -with materials liable to corrosion should always be pumped thoroughly prior to sampling in order to clear all accumulated corrosion products from the system. Where representative samples are required from predetermined depths in the aquifer, sampling tubes to each depth in the bore- hole, or separate boreholes to each depth, should be employed. 97 sea, Bottom deposits in ri lakes an d reservoirs vers, estuaries and the Sampling patterns should be established to take account of variations of composition in both vertical and horizontal direc- tions. It may be necessary to obtain information on the depth of a bottom deposit or on its composition at different depths. Many factors important in sampling waters, such as the boats, also apply to the sampling of bottom deposits. use of Substrata are usually heterogeneous and special care should be taken to ensure that a sufficient number of samples is taken to provide a representative assessment of the parameter(s) under consideration. 9.8 Drinking water 9.8.1 Water being pumped into supply The sampling point should be selected so as to permit monitor- ing of residual disinfecting agents before any loss occurs but after all reactions are completed, for example, monitoring of residual chlorine after complete reaction of sulphur dioxide with excess chlorine. Sampling for routine bacteriological examina- tion is also required and suitable precautions, including any national safety regulations, should be observed. The usual sampling point is a tap connected directly to the pumping main. The sampling tap should have no attachments 6 SIST EN 25667-1:1996



IS0 5667/l-1980 (E) and should be suitable for sterilization by flaming. The material of the sample pipe shall be carefully chosen in relation to the test requirements, for example, copper pipe may lead to an increase in the copper concentration in the water and a decrease in bacterial count. In order to make sure that the sam- ple is drawn directly from the tap into the container, the sample container should be placed immediately below the tap but not connected to it, nor in direct contact with it. 9.8.2 Service reservoirs Samples should be taken from a tap fitted to the outlet main as close as possible to the reservoir. Many service reservoirs are designed so that they fill and empty through the same main, and therefore care is nee
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