Introduction to Municipal Water Quality Management

209 Pages·2023·13.237 MB·English

by  Johannes Haarhoff

INTRODUCTION TO MUNICIPAL WATER
QUALITY MANAGEMENT

INTRODUCTION TO MUNICIPAL WATER
QUALITY MANAGEMENT
Johannes Haarhoff
First published 2023
by Routledge
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and by Routledge
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Routledge is an imprint of the Taylor & Francis Group, an informa business
© 2023 University of South Africa
The right of Johannes Haarhoff to be identified as the author of this work has been asserted in
accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form
or by any electronic, mechanical, or other means, now known or hereafter invented, including
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are used only for identification and explanation without intent to infringe.
Print edition not for sale in Sub-Saharan Africa
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
ISBN: 9781032493954 (hbk)
ISBN: 9781032493961 (pbk)
ISBN: 9781003393573 (ebk)
DOI: 10.4324/9781003393573
Typeset in Times New Roman
by UNISA Press, South Africa
CONDENSED CONTENTS

Illustrations vii

Tables vii

Figures ix

Preface xi

Foreword xii

PART I: DRINKING WATER QUALITY
1 Standards 3

2 Compliance 17

PART II: DRINKING WATER TREATMENT
3 Chemicals 31

4 Coagulation and Flocculation 47

5 Stabilisation 61

6 Disinfection 77

7 Adsorption 97

8 Residue 111

PART III: RECREATIONAL WATER
9 Quality 129

10 Swimming Pool Management 143

PART IV: BULK WATER SUPPLY
11 Hydrology 163

12 Storage Dams 175

Index 189

v

ILLUSTRATIONS

TABLES
Table 1.1 Microbiological water quality parameters
Table 1.2 Physical and aesthetic water quality parameters
Table 1.3 Chemical (macro-determinands) water quality parameters
Table 1.4 Chemical (micro-determinands) water quality parameters
Table 1.5 Organic water quality parameters
Table 2.1 Minimum monitoring for process indicators
Table 2.2 Minimum samples for E. coli or faecal coliforms in distribution systems
Table 2.3 Sampling frequencies for risk determinands
Table 2.4 Categorisation of water quality indices
Table 3.1 Chemicals used for pH adjustment
Table 3.2 Chemicals used for disinfection
Table 3.3 Chemicals used for coagulation
Table 3.4 Mandatory information for Material Safety Data Sheets
Table 5.1 Limitations of the Langelier index
Table 5.2 Effect of acidic chemicals on alkalinity
Table 5.3 Effect of alkaline chemicals on alkalinity
Table 6.1 Reference and surrogate organisms for three microbiological classes
Table 6.2 Log removal credits for physical treatment barriers
Table 6.3 Required CT values for Giardia inactivation at 15°C by free chlorine
vii
ILLUSTRATIONS
Table 6.4 Required CT values for virus inactivation by free chlorine at pH 6.0 to
pH 9.0
Table 6.5 Required CT values for Giardia inactivation by monochloramine at pH 6.0
to pH 9.0
Table 6.6 Required CT values for virus inactivation by monochloramine
Table 6.7 Required CT values for Giardia inactivation by chlorine dioxide at pH 6.0 to
pH 9.0
Table 6.8 Required CT values for virus inactivation by chlorine dioxide at pH 6.0 to
pH 9.0
Table 6.9 Required CT values for Giardia inactivation by ozone
Table 6.10 Required CT values for virus inactivation by ozone
Table 6.11 Comparison of required CT values at water temperature of 15°C and pH 8.0
Table 6.12 Typical tank layouts with appropriate baffling factors
Table 7.1 Isotherm constants from the literature
Table 8.1 Practical design values for different float layer removal methods
Table 8.2 Design parameters for new sludge lagoons at the Vaalkop Water
Treatment Plant
Table 8.3 Deterioration in backwash water quality
Table 9.1 Guidelines for pH in full contact recreational water
Table 9.2 HACCP applied to recreational water
Table 9.3 Pathogens in raw sewage
Table 9.4 Risk indicators for full contact recreation
Table 9.5 Risk indicators for intermediate contact recreation
Table 9.6 Blue Flag microbiological limits
Table 10.1 Guidelines for required pool area per bather
Table 11.1 Reduction factor to convert from 1:100 year rainfall to other return periods
Table 12.1 Seven large dams, in terms of storage capacity, in Southern Africa
Table 12.2 Risk classification system used by the Dam Safety Office (number of dams
in brackets)
viii
FIGURES
Figure 1.1 Relationships amongst classes of emerging contaminants
Figure 1.2 Pathways of contaminants in the water use cycle
Figure 2.1 Possible outcomes of risk monitoring
Figure 4.1 Removal range of particle separation processes
Figure 4.2 Effect of flocculation time on flocculation efficiency for G = 40 s-1
Figure 4.3 Effect of mixing intensity on flocculation efficiency for t = 9 minutes
Figure 5.1 The carbonic system in water
Figure 5.2 Electron micrograph of calcite crystals
Figure 5.3 Electron micrograph of aragonite crystals on sand grains
Figure 6.1 Dissociation of hypochlorous acid
Figure 6.2 Schematic top views of tanks with different degrees of short-circuiting,
stagnant zones depicted darker
Figure 6.3 Interpolation sequence for Example 6.7
Figure 7.1 Electron micrographs of different activated carbons at different scales
Figure 7.2 Isotherm examples for geosmin, 2-MIB, chloroform and bromoform
Figure 7.3 Schematic of breakthrough in a GAC column
Figure 8.1 Relative volumetric and mass flows from typical water treatment plants
Figure 10.1 Schematic layout of a domestic swimming pool
Figure 10.2 Schematic layout of a municipal swimming pool
Figure 10.3 Pool dimensions for Example 10.3
Figure 10.4 Inhibition of chlorine efficiency by cyanuric acid
Figure 11.1 Distribution of water on earth
Figure 11.2 Average available water per person since 1962
Figure 11.3 Number of registered South African rainfall gauges since 1925
Figure 11.4 Number of registered South African runoff gauges since 1925
ix