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Water Safety Plans | November 2010
Household and small community water safety
Household and small community water safety
Kuching2 November 2010
Bruce GordonWater, Sanitation, Hygiene and Health
Water Safety Plans | November 2010
Guidelines for Drinking-water Quality (GDWQ)
Guidelines for Drinking-water Quality (GDWQ)
Flagship normative publications of WHO.
– Demand for the document is among the highest and most sustained of all WHO publications.
Water Safety Plans | November 2010
WHO Guidelines for Drinking Water Quality, Framework for Safe Drinking Water:
WHO Guidelines for Drinking Water Quality, Framework for Safe Drinking Water:
Health-based targets(National regulatory body)
Independent surveillance(Surveillance agency)
Water Safety Plan(Water utility)
External audit of WSP
Verification monitoring
Risk management plan
Implementation of step-wise improvements
Continuous monitoring
Documentation and supporting programmes
Considers overall public health context and contribution of drinking-water to disease burden
Eventually need to be expressed as Water Quality, Performance, or Technology Targets
Water Safety Plans | November 2010
Water Safety Plan (simplified) Water Safety Plan (simplified)
Continuous cycle
What are the risks?
How do I control the risks?Monitoring
Source: Netti et al. 2005
Water Safety Plans | November 2010
Water Safety Plans Water Safety Plans
System mapping Risk Assessment Control measures
Monitoring + verification
Improvements (e.g. investment planning)
WSP stepsWSP steps
Water Safety Plans | November 2010
• Paradigm shift (from reactive to preventive)• But common sense ("sanitary survey +")
Water Safety Plans | November 2010
Benefits of WSP approachBenefits of WSP approach
Reduce disease
Risk-based approach
Enhance good practice
Evidence-based investments
Save money in the long-term
Water Safety Plans | November 2010
Small Community Water Supplies – the need for a WSP approach
Small Community Water Supplies – the need for a WSP approach
Undertrained operators
Varying and inconsistent perception of risks
Unclear roles and responsibilities;
Limited resources
More frequently associated with waterborne disease in both developed & developing countries
Water Safety Plans | November 2010
The case for HWTSThe case for HWTS
Dramatically improves microbial water quality
Significantly reduces diarrhoea
Among the most effective of water, sanitation, and hygiene interventions
Can be rapidly deployed and taken up by vulnerable populations
Water Safety Plans | November 2010
WHO Guidelines for Drinking-water Quality WHO Guidelines for Drinking-water Quality
"HWTS has been shown to significantly improve water quality and reduce waterborne infectious disease risks"
Water Safety Plans | November 2010
Effectiveness ranges of HWTS technologies for the reduction of microbes in water
Effectiveness ranges of HWTS technologies for the reduction of microbes in water
Disinfection/coagulation
Household slow sand filtration
Fiber and fabric filters
Diatomaceous earth filters
Thermal treatment
UV irradiation
Solar disinfection
Free chlorine disinfection
Settling/sedimentation
Porous ceramic filtration
0 1 2 3 4 5 6 7 8 9
Log(10) reduction of microbes
Bacteria
Viruses
Protozoa
Courtesy of Mark Sobsey, University of North Carolina
Water Safety Plans | November 2010
The Need for a NetworkThe Need for a Network
Looking Back: the situation in 2003
• lack of awareness of effectiveness, and cost effectiveness
• lack of supportive policies
• limited cooperation: fragmented advocacy, research and implementation efforts
• limited tools available to support implementation
• major gaps in implementation research
Response: Establishment of an International Network
Water Safety Plans | November 2010
Limitations of HWTS Limitations of HWTS
Does not improve access to water (quantity)
Does not provide the health and economic benefits associated with a regular, piped-into home, water supply
Places the burden of water quality management on consumers
Demands a lot from householders, requiring: – Consistent and sustained behaviour change– Time investments to manage water – Financial investments
Water Safety Plans | November 2010
Current Evidence (simplified) Current Evidence (simplified)
Intervention Effect size on diarrhoea
morbidity
Reduction (percent)
Reference
Water quality, under 12 months 0.56 44% Waddington et al. 20091
Water quality, after 12 months or more 0.81 19% Waddington et al. 20091
Sustainable impact
Water Safety Plans | November 2010
Challenges Challenges
Has not achieved sustained pubic health impact
Government have not developed comprehensive policies or regulations addressing (non-boiling) HWTS options as part of their overall water safety efforts
Largely a small-scale intervention undertaken by NGOs in isolation from central government-formulated drinking-water supply programmes
Water Safety Plans | November 2010
NO!NO!
For many vulnerable populations, HWTS remains the only viable approach to rapidly improving water safety
Immense potential health and other benefits associated with ultimately succeeding in scaling-up HWTS
Challenges are significant, but are not dissimilar to those that had been faced previously by successful current interventions
– (e.g. bednets to protect against malaria).