Contents -- Preface -- Acknowledgements -- Acronyms and abbreviations used in text -- 1. Introduction -- 1.1 General considerations and principles -- 1.1.1 Microbial aspects -- 1.1.2 Disinfection -- 1.1.3 Chemical aspects -- 1.1.4 Radiological aspects -- 1.1.5 Acceptability aspects -- 1.2 Roles and responsibilities in drinking-water safety management -- 1.2.1 Surveillance and quality control -- 1.2.2 Public health authorities -- 1.2.3 Local authorities -- 1.2.4 Water resource management -- 1.2.5 Drinking-water supply agencies -- 1.2.6 Community management -- 1.2.7 Water vendors -- 1.2.8 Individual consumers -- 1.2.9 Certification agencies -- 1.2.10 Plumbing -- 1.3 Supporting documentation to the guidelines -- 2. The Guidelines: a framework for safe drinking-water -- 2.1 Framework for safe drinking-water: requirements -- 2.1.1 Health-based targets -- 2.1.2 System assessment and design -- 2.1.3 Operational monitoring -- 2.1.4 Management plans, documentation and communication -- 2.1.5 Surveillance of drinking-water quality -- 2.2 Guidelines for verification -- 2.2.1 Microbial water quality -- 2.2.2 Chemical water quality -- 2.3 National drinking-water policy -- 2.3.1 Laws, regulations and standards -- 2.3.2 Setting national standards -- 2.4 Identifying priority drinking-water quality concerns -- 2.4.1 Assessing microbial priorities -- 2.4.2 Assessing chemical priorities -- 3. Health-based targets -- 3.1 Role and purpose of health-based targets -- 3.2 Types of health-based targets -- 3.2.1 Specified technology targets -- 3.2.2 Performance targets -- 3.2.3 Water quality targets -- 3.2.4 Health outcome targets -- 3.3 General considerations in establishing health-based targets -- 3.3.1 Assessment of risk in the framework for safe drinking-water -- 3.3.2 Reference level of risk -- 3.3.3 Disability-adjusted life-years (DALYs) -- 4. Water safety plans.

4.1 System assessment and design -- 4.1.1 New systems -- 4.1.2 Collecting and evaluating available data -- 4.1.3 Resource and source protection -- 4.1.4 Treatment -- 4.1.5 Piped distribution systems -- 4.1.6 Non-piped, community and household systems -- 4.1.7 Validation -- 4.1.8 Upgrade and improvement -- 4.2 Operational monitoring and maintaining control -- 4.2.1 Determining system control measures -- 4.2.2 Selecting operational monitoring parameters -- 4.2.3 Establishing operational and critical limits -- 4.2.4 Non-piped, community and household systems -- 4.3 Verification -- 4.3.1 Verification of microbial quality -- 4.3.2 Verification of chemical quality -- 4.3.3 Water sources -- 4.3.4 Piped distribution systems -- 4.3.5 Verification for community-managed supplies -- 4.3.6 Quality assurance and quality control -- 4.4 Management procedures for piped distribution systems -- 4.4.1 Predictable incidents ("deviations") -- 4.4.2 Unforeseen events -- 4.4.3 Emergencies -- 4.4.4 Closing supply, water avoidance and "boil water" orders -- 4.4.5 Preparing a monitoring plan -- 4.4.6 Supporting programmes -- 4.5 Management of community and household water supplies -- 4.6 Documentation and communication -- 5. Surveillance -- 5.1 Types of approaches -- 5.1.1 Audit -- 5.1.2 Direct assessment -- 5.2 Adapting approaches to specific circumstances -- 5.2.1 Urban areas in developing countries -- 5.2.2 Surveillance of community drinking-water supplies -- 5.2.3 Surveillance of household treatment and storage systems -- 5.3 Adequacy of supply -- 5.3.1 Quantity (service level) -- 5.3.2 Accessibility -- 5.3.3 Affordability -- 5.3.4 Continuity -- 5.4 Planning and implementation -- 5.5 Reporting and communicating -- 5.5.1 Interaction with community and consumers -- 5.5.2 Regional use of data -- 6. Application of the Guidelines in specific circumstances -- 6.1 Large buildings.

6.1.1 Health risk assessment -- 6.1.2 System assessment -- 6.1.3 Management -- 6.1.4 Monitoring -- 6.1.5 Independent surveillance and supporting programmes -- 6.1.6 Drinking-water quality in health care facilities -- 6.1.7 Drinking-water quality in schools and day care centres -- 6.2 Emergencies and disasters -- 6.2.1 Practical considerations -- 6.2.2 Monitoring -- 6.2.3 Microbial guidelines -- 6.2.4 Sanitary inspections and catchment mapping -- 6.2.5 Chemical and radiological guidelines -- 6.2.6 Testing kits and laboratories -- 6.3 Safe drinking-water for travellers -- 6.4 Desalination systems -- 6.5 Packaged drinking-water -- 6.5.1 Safety of packaged drinking-water -- 6.5.2 Potential health benefits of bottled drinking-water -- 6.5.3 International standards for bottled drinking-water -- 6.6 Food production and processing -- 6.7 Aircraft and airports -- 6.7.1 Health risks -- 6.7.2 System risk assessment -- 6.7.3 Operational monitoring -- 6.7.4 Management -- 6.7.5 Surveillance -- 6.8 Ships -- 6.8.1 Health risks -- 6.8.2 System risk assessment -- 6.8.3 Operational monitoring -- 6.8.4 Management -- 6.8.5 Surveillance -- 7. Microbial aspects -- 7.1 Microbial hazards associated with drinking-water -- 7.1.1 Waterborne infections -- 7.1.2 Persistence and growth in water -- 7.1.3 Public health aspects -- 7.2 Health-based target setting -- 7.2.1 Health-based targets applied to microbial hazards -- 7.2.2 Risk assessment approach -- 7.2.3 Risk-based performance target setting -- 7.2.4 Presenting the outcome of performance target development -- 7.2.5 Issues in adapting risk-based performance target setting to national/local circumstances -- 7.2.6 Health outcome targets -- 7.3 Occurrence and treatment of pathogens -- 7.3.1 Occurrence -- 7.3.2 Treatment -- 7.4 Verification of microbial safety and quality -- 7.5 Methods of detection and faecal indicator bacteria.

8. Chemical aspects -- 8.1 Chemical hazards in drinking-water -- 8.2 Derivation of chemical guideline values -- 8.2.1 Approaches taken -- 8.2.2 Threshold chemicals -- 8.2.3 Alternative approaches -- 8.2.4 Non-threshold chemicals -- 8.2.5 Data quality -- 8.2.6 Provisional guideline values -- 8.2.7 Chemicals with effects on acceptability -- 8.2.8 Non-guideline chemicals -- 8.2.9 Mixtures -- 8.3 Analytical aspects -- 8.3.1 Analytical achievability -- 8.3.2 Analytical methods -- 8.4 Treatment -- 8.4.1 Treatment achievability -- 8.4.2 Chlorination -- 8.4.3 Ozonation -- 8.4.4 Other disinfection processes -- 8.4.5 Filtration -- 8.4.6 Aeration -- 8.4.7 Chemical coagulation -- 8.4.8 Activated carbon adsorption -- 8.4.9 Ion exchange -- 8.4.10 Membrane processes -- 8.4.11 Other treatment processes -- 8.4.12 Disinfection-by-products - process control measures -- 8.4.13 Treatment for corrosion control -- 8.5 Guideline values for individual chemicals, by source category -- 8.5.1 Naturally occurring chemicals -- 8.5.2 Chemicals from industrial sources and human dwellings -- 8.5.3 Chemicals from agricultural activities -- 8.5.4 Chemicals used in water treatment or from materials in contact with drinking-water -- 8.5.5 Pesticides used in water for public health purposes -- 8.5.6 Cyanobacterial toxins -- 9. Radiological aspects -- 9.1 Sources and health effects of radiation exposure -- 9.1.1 Radiation exposure through drinking-water -- 9.1.2 Radiation-induced health effects through drinking-water -- 9.2 Units of radioactivity and radiation dose -- 9.3 Guidance levels for radionuclides in drinking-water -- 9.4 Monitoring and assessment for dissolved radionuclides -- 9.4.1 Screening of drinking-water supplies -- 9.4.2 Strategy for assessing drinking-water -- 9.4.3 Remedial measures -- 9.5 Radon -- 9.5.1 Radon in air and water -- 9.5.2 Risk.

9.5.3 Guidance on radon in drinking-water supplies -- 9.6 Sampling, analysis and reporting -- 9.6.1 Measuring gross alpha and gross beta activity concentrations -- 9.6.2 Measuring potassium-40 -- 9.6.3 Measuring radon -- 9.6.4 Sampling -- 9.6.5 Reporting of results -- 10. Acceptability aspects -- 10.1 Taste, odour and appearance -- 10.1.1 Biologically derived contaminants -- 10.1.2 Chemically derived contaminants -- 10.1.3 Treatment of taste, odour and appearance problems -- 10.2 Temperature -- 11. Microbial fact sheets -- 11.1 Bacterial pathogens -- 11.1.1 Acinetobacter -- 11.1.2 Aeromonas -- 11.1.3 Bacillus -- 11.1.4 Burkholderia pseudomallei -- 11.1.5 Campylobacter -- 11.1.6 Escherichia coli pathogenic strains -- 11.1.7 Helicobacter pylori -- 11.1.8 Klebsiella -- 11.1.9 Legionella -- 1.1.10 Mycobacterium -- 11.1.11 Pseudomonas aeruginosa -- 11.1.12 Salmonella -- 11.1.13 Shigella -- 11.1.14 Staphylococcus aureus -- 11.1.15 Tsukamurella -- 11.1.16 Vibrio -- 11.1.17 Yersinia -- 11.2 Viral pathogens -- 11.2.1 Adenoviruses -- 11.2.2 Astroviruses -- 11.2.3 Caliciviruses -- 11.2.4 Enteroviruses -- 11.2.5 Hepatitis A virus -- 11.2.6 Hepatisis E virus -- 11.2.7 Rotaviruses and orthoreoviruses -- 11.3 Protozoan pathogens -- 11.3.1 Acanthamoeba -- 11.3.2 Balantidium coli -- 11.3.3 Cryptosporidium -- 11.3.4 Cyclospora cayetanensis -- 11.3.5 Entamoeba histolytica -- 11.3.6 Giardia intestinalis -- 11.3.7 Isospora belli -- 11.3.8 Microsporidia -- 11.3.9 Naegleria fowleri -- 11.3.10 Toxoplasma gondii -- 11.4 Helminth pathogens -- 11.4.1 Dracunculus medinensis -- 11.4.2 Fasciola spp. -- 11.5 Toxic cyanobacteria -- 11.6 Indicator and index organisms -- 11.6.1 Total coliform bacteria -- 11.6.2 Escherichia coli and thermotolerant coliform bacteria -- 11.6.3 Heterotrophic plate counts -- 11.6.4 Intestinal enterococci -- 11.6.5 Clostridium perfringens.

11.6.6 Coliphages.