WORLD METEOROLOGICAL ORGANIZATION OPERATIONAL HYDROLOGY REPORT No. 27 MANUAL ON WATER-QUALITY MONITORING PLANNING AND IMPLEMENTATION OF SAMPLING AND FIELD TESTING WMO - No. 680 I SECRETARIAT OF 11IE WORLD METEOROLOGICAL ORGANIZATION - GENEVA - SWITZERLAND © 1988, World Meteorological Organization ISBN 92 - 63 - 10680 - 0 NOTE The designations employed and the presentation of material in this publication do not imply the expression ofany opinion whatsoever on the part of the Secretariat ofthe World Meteorological Organization concern­ ing the legal status of any country, territory, city or area, or of its authori­ ties, or concerning the delimitation ofits frontiers or boundaries. CONTENTS Page Foreword ix Summary (English, French, Russian, Spanish) xi Chapter 1 - Introduction 1 1.1 Why should water quality be monitored? . 2 1.2 Water-quality management 2 1.3 General considerations 2 1.4 Objectives for water-quality monitoring programmes 4 1.5 Planning ofwater-quality measurement networks 6 1.5.1 Location ofsampling stations 7 1.5.2 . Methods of sampling . 7 1.5.3 Frequency of sampling .. 8 1.5.4 Water-quality parameters 8 1.5.5 Data handling 8 1.5.6 Costs . 8 1.5.7 Documentation . 9 Chapter 2 • General water sampling considerations 9 2.1 Introduction . 11 2.2 Location ofwater-quality sampling sites 11 2.2.1 Varieties of water bodies 11 2.2.2 River basins 12 2.2.3 Lakes . 12 2.2.4 Groundwater 14 2.2.5 Other . 17 2.3 Representative samples 17 2.3.1 Time variability 17 2.3.2 Space variability 18 2.4 Frequency of sampling 19 --------- ---. --- ----- --- --------------- -- --- iv CONTENTS Page 2.5 Flow measurements 24 2.6 Water-quality parameters 26 2.7 Field quality assurance 33 2.7.1 General measures . 33 2.7.2 The sample collector . 33 2.7.3 Prevention of sample contamination 34 2.7.4 Quality assurance 36 2.7.4.1 Bottle blanks 36 2.7.4.2 Sampler blanks 36 2.7.4.3 Filter blanks . 36 2.7.4.4 Field blanks . 37 2.7.4.5 Duplicate samples (splits) 37 2.7.4.7 Spiked samples 32 Chapter 3 • Collecting surface-water samples 39 3.1 Types of surface-water samples 39 3.1.1 Grab samples 39 3.1.2 Composite samples 40 3.1.2.1 Sequential, or time, composite 40 3.1.2.2 Flow-proportional composite 40 3.2 Collecting a representative water sample 41 3.3 Field equipment and techniques 42 3.3.1 Grab-water samplers 42 3.3.1.1 Depth-integrating samplers 42 3.3.1.2 Discrete samplers 43 3.3.2 Dissolved-oxygen sampler 48 3.3.3 Automatic samplers . 49 3.4 Sampling procedures as influenced by station location and season 50 3.4.1 Sampling procedures from bridges, abutments, boats and aircraft 50 3.4.2 Sampling procedures from shores, stream banks and wharves 51 3.4.3 Winter sampling procedures 52 CONTENTS v Page 3.5 Preparation for field trips 53 3.5.1 General preparation ... 53 3.5.2 Bottle washing and preparation 54 3.5.3 Selection of sample volume .. 54 3.5.4 Checklist prior to field trip . 55 Chapter 4 - Field-measured parameters 61 4.1 pH measurement 61 4.1.1 Procedure for taking pH measurements 62 4.1.2 Maintenance ofpH probes . 63 4.2 Conductivity measurement . 63 4.2.1 Procedure for taking conductivity measurements 64 4.2.2 Conductivity meter and probe maintenance . 65 4.3 Dissolved-oxygen measurement 65 4.3.1 Sampling 66 4.3.2 Dissolved-oxygen meters 66 4.3.3 Winkler analysis .. 67 4.3.3.1 Winkler reagents .. 67 4.3.3.2 Winkler procedure 68 4.3.4 Hach method 70 4.4 Temperatore measurement 71 4.5 Turbidity measurement . 72 4.6 Colour .. 73 4.7 Transparency·..··· 74 4.8 General summary offield procedures 74 Chapter 5 - Recording offield data .. 77 5.1 Station-location descriptions . 77 5.2 Station data forms .. 79 5.3 Field sheets .. .. .. 81 vi CON1ENTS Page Chapter 6 • Field filtration and preservation procedures . 101 6.1 Filtration 101 6.1.1 General apparatus-washing procedures 102 6.1.2 Filtration procedures . 103 6.1.2.1 Particulate carbon and nitrogen 103 6.1.2.2 Chlorophyll a . 104 6.2 Preservation techniques 105 6.2.1 Containcrs 106 6.2.2 Chemical addition 106 6.2.3 Freezing 107 6.2.4 Refrigeration 107 6.2.5 Practical aspects ofpreservation 107 Chapter 7 - Sampling for radioactivity measurements 113 7.1 Sources ofradioactivity in water . 113 7.2 Collection and preservation of samples . 114 Chapter 8 • Sampling for biological analysis 117 8.1 Microbiological analysis 117 8.1.1 Sample containers . 117 8.1.2 Sample preservation 118 8.1.3 Sampling procedure . 118 8.2 Macrobiota 119 8.2.1 Sampling methods . 120 8.2.2 Sample preservation 120 Chapter 9 • Precipitation sampling 125 9.1 Site selection 126 9.2 Sample collectors 128 9.2.1 Snow collectors . 130 9.2.2 Dry-deposition collection . 130 CON1ENTS vii Page 9.3 Sample collection procedures 131 9.3.1 Definition of the end of the month . 131 9.3.2 Sample-handling procedures . 131 9.3.3 Prevention of sample contamination . 132 9.4 Records ofprecipitation samples ..... 133 Chapter 10 - Sediment sampling procedures 137 10.1 Site selection 140 IO.Ll Rivers 140 10.1.2 Lakes 141 10.2 Sample collection 141 10.2.1 Sampling frequency 141 10.2.2 Sample integrity . 142 10.3 Samplers . 142 10.3.1 Suspended-sediment samplers 142 10.3.2 Bottom-sediment samplers 143 10.3.2.1 Core samplers . 144 10.3.2.2 Grab samplers . 146 lOA Sample handling and preservation .... 150 1004.1 Suspended sediment 150 10,4.2 Bottom sediment . 151 Chapter 11 - Groundwater 153 ILl Site selection and sampling frequency 154 11.2 Sampling procedures 154 11.3 Field measurements 155 11.3.1 Water level . 155 11.3.2 Redox potential, Eh . 156 11.3.3 ZoBell solution . 157 viii CONTENTS Page Chapter 12 • Shipping ofsamples 161 12.1 heparation for shipping 161 12.2 Shipping labels 162 12.3 Labels or tags on individual bottles 162 12.4 Chain of custody .. 163 Chapter 13 • Field safety 165 13.1 General practices 166 13.2 Safety precautions when sampling from bridges 167 13.3 Safety precautions while wading 167 13.4 Safety precautions when sampliug from boats 168 13.5 Safety precautions when handling chemicals 169 13.6 Equipment . 170 13.7 Special precautions for cold climates . 170 13.8 Survival kit and rations . 171 Chapter 14· Training 173 14.1 Basic knowledge 173 14.2 Specialized training 173 14.2.1 External training 173 14.2.2 In-house training 174 14.2.3 Combined training 174 14.3 References 175 Chapter 15 • Glossary············ 181 Chapter 16 • Bibliography 195 FOREWORD In the context of its present-day definition, the assessment of water resources requires that due consideration be given to both the quantitative and quali­ tative aspects. However, while attention to water quantity dates as far back as man's interest in its storage and utilization, focus on water-quality issues bas been a com­ paratively recent development. Its importance is nevertheless gaining recognition in view ofthe growing global concern for protection ofthe environment. The WMO Commission for Hydrology (CHy) recognized the need for operational guidance material in the field of water-quality monitoring. Thus, in 1972 the Commission embarked on a project to initiate the preparation of this much­ needed guidance material. In subsequent years valuable contributions to the project in the form of technical notes were made by Mr J. Picard (France, 1972-1976), Mr H.R.S. Page (UK, 1976-1980) and Dr E. Rosenthal (Israel, 1980-1984). At its seventh session (Geneva, August/September 1984) the Commission requested the Secretary-General to arrange for the preparation of a manual on the subject on the basis of the material and' publications, ineluding those of other UN organizations, that had recently become available. This manual, which is a culmina­ tion of the CHy project, has been prepared with the assistance of Prof. Paul M. Laughton (Canada) and Dr Adrian Demayo (Canada), whose services were arranged through the kind collaboration of the Inland Waters Directorate of Environment Canada. This manual is intended as a practical handbook for those who plan water­ quality sampling programmes, for those who do the actual field work and for the training ofpersonnel on the subject ofwater-quality data collection. I am pleased to express to all who have contributed time and effort to this project and, in particular, to the preparation of this manual, the sincere appreciation ofthe World Meteorological Organization. It is hoped that this publication will assist national hydrological agencies responsible for operational hydrology in the develop­ ment and operation oftheir water-quality monitoring programmes. .j G.O.I'.Obasi (Secretary-General) SUMMARY This publication discusses the monitoring of the quality of inland waters, i.e. lakes, rivers, reservoirs, groundwater and precipitation, and describes in detail the planning, field activities and methods used in carrying out a water-quality monitoring programme. Chapter 1 contains a brief discussion on water-quality management, the objectives of water-quality monitoring programmes and the planning of water-quality measurement networks. Under general considerations in Chapter 2 details are pro­ vided on the location of monitoring stations, representativesness of samples, frequen­ cy of sampling, classification of water-quality parameters and the use of statistics in selecting sampling frequencies. Chapter 3 covcrs collection of surface-water samples with some discussion on thc type of samples and a detailed description of equipment and sampling techniques.