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Best Practice Guide on Sampling and Monitoring of Metals in Drinking Water

Best Practice Guide on Sampling and Monitoring of Metals in Drinking Water

Adam Postawa

(2012)

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Book Details

Abstract

Part of Metals and Related Substances in Drinking Water Set - buy all five books together to save over 30%!  
There is increasing concern regarding the presence of metals, particularly heavy metals in drinking water. In addition to the well-known toxic effects of lead, which are discussed at length in the Best Practice Guide on the Control of Lead in Drinking Water (in this series of Guides), the latest WHO guide values for maximum mean concentrations of arsenic, nickel and others in drinking water have been lowered compared to previous versions. European Union, USA and National standards for drinking water have followed the trend based largely on the same toxicological information. 
There is currently growing interest in the presence of hexavalent chromium in drinking water following its finding in some drinking waters in the USA above the national upper limit for total chromium and research suggesting that this limit needs to be considerably lowered. Some metals, particularly iron and manganese are associated with the production of discoloured (dirty) water in distribution systems and are therefore very important to the production of water with acceptable aesthetic qualities. Others (iron and aluminium) are key to the treatment of raw waters to drinking water standards. In most cases it is not possible to continuously monitor waters for metals and suitable sampling programmes must be designed and carried out to give results representative of the true water quality. 
The Best Practice Guide on Sampling and Monitoring of Metals in Drinking Water gives guidance on the design and quality control of sampling programmes for metals in Raw waters, in the water treatment works, in the drinking water distribution system and at the consumers tap. It also gives guidance on the analytical methods that can be used for the analysis of metals and quality control of those methods. Sampling programmes on the same water will vary according to the purpose for which they are carried out and the statistical techniques used to determine and design the different types of programme are outlined. Finally some case studies of optimisation of sampling are set out. 
Best Practice Guide on Sampling and Monitoring of Metals in Drinking Water is a valuable text for scientists, engineers and quality managers working in drinking water supply, laboratory managers and scientists who carry out sampling and analysis, and water industry consultants. It is also an excellent resource for post graduate and research workers in the field of drinking water. 
Editor: Dr Adam Postawa, AGH University, Krakow, Poland  
"Sampling plays a crucial role in a Drinking Water Safety Plan, the risk management plan of a drinking water treatment plant. This Best Practice Guide on the Sampling and Monitoring of Metals in Drinking Water gives the state-of-the-art tools to develop a sampling and monitoring programme for both operational and compliance monitoring." DR EDDO HOEKSTRA, Institute for Health and Consumer Protection, Joint Research Centre of the European Commission

Table of Contents

Section Title Page Action Price
Cover page 1
Half title page 2
Title page 4
Copyright page 5
Contents 6
About this Best Practice Guide 10
Authors 12
Acknowledgements 14
Acronyms 16
Definitions 18
Foreword 20
Executive Summary 22
Chapter 1 26
Introduction 26
1.1 THE SCOPE OF THE BEST PRACTICE GUIDE 26
1.2 THE ROLE OF SAMPLING AND MONITORING 27
The basis on which guideline values are set 27
Toxicity 27
Carcinogenicity 28
Acceptability aspects 28
Guidelines and regulations for drinking water quality 29
World Health Organization guidelines 29
European Union (EU) Council Directive 98/83/EC of 3rd Nov 1998 on the quality of water intended for human consumption 29
United States Environmental Protection Agency (US EPA) 31
Other standards 31
Raw waters 31
Water during treatment 32
Operational control 33
1.3 DRINKING WATER SAFETY PLANNING 34
The Bonn Charter for Safe Drinking Water 34
Drinking water safety plans 35
Chapter 2 38
Basic principles of sampling 38
2.1 HEALTH AND SAFETY 38
Lone worker arrangements 38
Raw water sampling 38
Monitoring instruments 39
Hazardous materials 39
Toxic gases 40
Confined spaces 40
2.2 DESIGN OF SAMPLING PROGRAMMES 40
System characteristics and archival data 41
Sampling location 41
Sample variability 41
2.3 SAMPLING TECHNIQUES 42
Spot samples 42
Periodic samples 42
Continuous samples 43
Series of samples 43
Composite samples 43
Large volume samples 43
2.4 SAMPLING EQUIPMENT 44
Sample bottles/containers 44
2.5 SAMPLE PRETREATMENT AND PRESERVATION 44
Filtration 44
Preservation 45
Sample identification 47
Avoidance of sample contamination 47
Transport and storage time 48
KEY POINTS: 48
Chapter 3 50
Quality assurance of sampling procedures 50
3.1 ROLE OF QUALITY ASSURANCE 50
3.2 SAMPLING STRATEGY 50
3.3 VALIDATION OF SAMPLING PROCEDURE 50
3.4 QUALITY CONTROL PROGRAMME 51
Replicate control samples 51
Blank/field blank samples 52
Spiked samples 54
KEY POINTS: 55
Chapter 4 56
Analytical methods for metals in water 56
4.1 SELECTION OF AN ANALYTICAL METHOD 56
4.2 COLORIMETRIC METHODS 57
4.3 ELECTROCHEMISTRY METHODS 59
4.4 ATOMIC ABSORPTION SPECTROSCOPY METHODS 60
4.5 INDUCTIVELY COUPLED PLASMA METHODS (ICP) 64
KEY POINTS: 65
Chapter 5 66
Analytical quality control 66
5.1 PERFORMANCE CHARACTERISTICS 66
5.2 INTERNAL QUALITY CONTROL 66
5.3 EXTERNAL QUALITY CONTROL 67
5.4 EXAMPLE OF AN ANALYTICAL QUALITY CONTROL PROGRAM 67
KEY POINTS: 68
Chapter 6 70
Monitoring metals in raw water resources 70
6.1 WHAT IS RAW WATER? 70
6.2 REASONS FOR MONITORING RAW WATER 70
6.3 TYPES OF SAMPLES 70
6.4 SAMPLING LOCATIONS 71
Surface waters 71
Lakes, ponds and reservoirs 71
Rivers and streams 74
Groundwater 74
Wells/Boreholes 74
Springs 79
6.5 SAMPLING FREQUENCY 79
6.6 SAMPLING DEVICES 80
Samplers, bailers 80
Pumps 82
6.7 AUTOMATIC SAMPLING AND ONLINE ANALYSIS SYSTEMS 84
6.8 PASSIVE SAMPLING 84
KEY POINTS: 85
Chapter 7 86
Sampling and monitoring metals in water treatment 86
7.1 METALS SIGNIFICANT FOR WATER TREATMENT 86
7.2 REASONS FOR MONITORING 87
Performance Monitoring 87
Process control 87
Regulatory compliance 87
Investigatory 88
7.3 MONITORING LOCATIONS 88
Sample lines 88
Sample taps 88
Labelled treatment works final water sample tap, outside WTW 90
Dip sampling 90
7.4 METHODS OF MONITORING 90
On-site analysis 91
Sampling for analysis by remote laboratory 91
7.5 INTERPRETATION OF DATA 91
Investigating failures of standards at treatment works 91
KEY POINTS: 92
Chapter 8 94
Monitoring metals in distribution systems 94
8.1 METALS CAUSING PROBLEMS IN DISTRIBUTION SYSTEMS 94
8.2 REASONS FOR MONITORING 95
Investigatory 95
Incident management 95
Regulatory compliance 95
Operational 95
Investment planning and appraisal 95
8.3 PLANNING A SAMPLE SURVEY 95
8.4 MONITORING LOCATIONS Storage points 96
Hydrants and standpipes 97
Ferrule tapings 97
Meter chambers/boundary boxes 97
8.5 METHODS OF MONITORING 97
On-line monitors 97
On-site analysis 97
Sampling for analysis by remote laboratory 98
8.6 INTERPRETATION OF DATA 98
What do results mean? 98
KEY POINTS: 99
Chapter 9 100
Monitoring metals at consumers’ taps 100
9.1 RELEVANCE OF CONSUMER’S TAP 100
9.2 SAMPLING METHODS 100
Fully flushed samples 100
First draw samples 101
Proportional samples 102
Stagnation samples 103
Random daytime samples (RDT) 104
9.3 ZONAL MONITORING 105
Definition of water supply systems for monitoring and control purposes 105
Compliance monitoring 106
Inventory monitoring 107
Variation in results from random daytime sampling 107
Using statistical tools to assess confidence in RDT sample results 107
Benchmark monitoring at selected properties 108
9.4 INVESTIGATIONS AT INDIVIDUAL PROPERTIES 109
Investigating problems 109
KEY POINTS: 110
Chapter 10 112
Statistical tools for the evaluation of results 112
10.1 BASIC DEFINITIONS 112
Errors 112
Total error 112
Random errors 112
Systematic error (bias) 113
Gross errors 113
Descriptive statistics 114
Measures of location (central tendency) 114
Measures of spread 114
Measures of skewness 115
Measures of kurtosis 115
Data distributions 115
10.2 SELECTED PARAMETRIC AND NONPARAMETRIC STATISTICAL TESTS 116
Distribution estimation 116
One-sample t test 117
F-test of equality of variances 118
10.3 CONFIDENCE INTERVAL FOR MEAN 118
10.4 COMPLIANCE WITH THRESHOLDS 119
Compliance with thresholds expressed as means or percentiles 119
Non – parametric methods 120
10.5 ANOVA AND ROBUST ANOVA 121
10.6 DATA PRESENTATION 123
Box-plot 123
Histogram 124
Probability plots 124
Control charts 124
Scheme of control chart construction and interpretation (Croll, 2010) 127
Mean and range control charts 127
KEY POINTS: 131
Chapter 11 132
Developing monitoring strategies 132
11.1 SOURCE TO TAP OVERVIEW 132
11.2 REASONS FOR MONITORING 132
The main reasons for monitoring are: 132
Compliance: 132
Inventory: 132
Operational: 132
Risk assessment: 134
11.3 CONSEQUENCES OF INADEQUATE MONITORING DATA 135
11.4 STEPS TO DEVELOPING A SUCCESSFUL MONITORING STRATEGY 135
KEY POINTS: 135
Appendix 1 136
Case studies 136
A1.1 BUCHAREST (RO) 136
Description of area: 136
Drinking water supplier: 136
Source of raw water: 136
Sampling points: 137
Sampling techniques: 137
Monitoring data: 137
Source of data: 137
Recommendations: 138
A1.2 ENGLAND AND WALES (UK) 138
Description of area: 138
Drinking water supplier: 138
Source of raw water: 138
Sampling points: 138
Sampling techniques: 138
Monitoring data: 138
Lead (Pb) 138
Copper (Cu) 139
Iron (Fe) 140
Nickel (Ni) 140
Source of data (2005 to 2010): 141
Conclusions: 141
A1.3 KRAKOW (PL) 141
Description of area: 141
Drinking water supplier: 141
Source of raw water: 141
Sampling points: 141
Sampling techniques: 141
Monitoring data: 142
Source of data 142
Recommendations: 142
A1.4 MYSZKOW (PL) 142
Description of area: 142
Drinking water supplier: 142
Source of raw water: 142
Sampling points 143
Sampling techniques: 143
Monitoring data: 143
Source of data 143
Recommendations 143
A1.5 TARGU MURES (RO) 143
Description of area: 144
Drinking water supplier: 144
Source of raw water: 144
Sampling points: 144
Sampling techniques: 144
Monitoring data: 144
Source of data: 145
Recommendations 145
A1.6 TIMISOARA (RO) 146
Description of area: 146
Drinking water supplier: 146
Source of raw water: 146
Sampling points: 146
Sampling techniques: 146
Monitoring data: 147
Source of data 147
Recommendations: 148
References 150