Health benefits of point-of-use water treatment systems Bettina Genthe 2 October 2012

Links of poor water and sanitation services to poverty In addition to direct health effects, the United Nations Millennium Declaration confirmed the central role of water and sanitation in sustainable development and the major contribution expanded access to safe drinking water and adequate sanitation can make to poverty alleviation (WHO, 2004). The poor bear the brunt of inadequate water services more than those with money in financial terms too. They pay high prices where water is sold, yet often have unreliable supplies, and so do not get value for money as do the rich. The poor are also less able to adopt strategies to lower risk where water supply is unreliable, such as investing in storage or treatment technologies

The World Health Organization (WHO) concluded that there was now “conclusive evidence that simple, acceptable, low-cost interventions at the household and community level are capable of dramatically improving the microbial quality of household stored water and reducing the attendant risks of diarrheal disease and death” (WHO, 2007). © CSIR

Economic benefits of improvements in drinking water quality According to the WHO assessment (2004), achieving the water and sanitation MDG target would bring economic benefits, ranging from US$3 to US$34 per US$ invested, depending on the region. Additional improvement of drinking-water quality, such as point-of- use disinfection, in addition to access to improved water and sanitation would lead to a benefit ranging from US$5 to US$60 per US$1 invested. In addition, health and the socio-economic benefits accrue when improving access to safe water supply and sanitation. © CSIR

Cost of diarrhoea in Olifants catchment Description < RDP (Low service level) Direct health costs (R3 769) >RDP (High service level) Direct health costs (R 3 349) Number of people Estimated diarrhoea incidences # of cases treated(8%) (5%) Average Treatment costsR 3 769R Total Direct Health costsR R Total number of people Total direct cost R (R208 per person) The Economic Burden of Diarrhoeal Disease in the Olifants WMA, SA. Steyn M, Maherry A and Genthe, B 2011

Economic burden of diarrhoea © CSIR 2010Slide # Image Pollution Prevention is cheaper than Treatment Providing people with >RDP level water is cheaper than the cost of Diarrhoea

Cause of death South Africa is one of a few countries globally where the under five mortality rate has increased rather than decreased (60 per 1,000 live births in 1990 to 66 per 1,000 live births in 2003) (UNICEF, 2005). Diarrhoeal disease is the third largest cause of death among children under the age of five in South Africa. Fewtrell et al., (2007) quantified the health impact in countries with incomplete water and sanitation coverage. They estimated that services related to water, sanitation and hygiene (WSH) are responsible for between 70 and 90% of diarrhoea in areas where coverage is below 98%. © CSIR

South Africa Approx 12% of population have no improved water supply nor sanitation © CSIR

Types of point of use systems Solar disinfection (SODIS) Filters © CSIR

Chemical disinfection Biosand filter © CSIR

Combination approach - Amadrum © CSIR

Effectiveness of the various Point-of-Use systems Intervention Result Log reduction SODIS Viruses 2- 3 log Bacteria 4 log Parasites 4 log Chlorination Viruses 3-4 Bacteria 3-4 log Parasites 2-3 log Floc filter + disinfect (PuR) &WaterMaker – produced in SA Viruses 5 log Bacteria 8 log Parasites 4 log Ceramic filter candles Virus 0.5 log Bacteria 4 log Parasites 3 log Ceramic Pot filters Virus 0.5 log Bacteria log Parasites log Sand Filtration (BioSand) Virus 0.5 log Bacteria 2 log Parasites 1 log

Diarrhoeal disease reduction by technology source Sobsey et al 2008 TechnologyDiarrhoeal reduction SODIS31% (26%-37%) Disinfection and safe storage37% (25%- 48%) Coagulation /chlorination31% (18%- 42%) Ceramic candle filtration63% (51%-72%) Ceramic pot filters46% (29%-59%) Biosand filter47% (21%-64%) © CSIR

Advantages and disadvantages of point-of-use water quality interventions Advantages of combined treatment systems Disadvantages Highly effective against all waterborne pathogens. Can be applied to high turbidity waters, and waters with high pH and low temperatures Provides a residual level of free chlorine No need for highly skilled labour, so only moderate level of training required, Visually observable improvement in water quality (turbidity reduction). Expensive (initial cost of US$5- 10/household for vessel + annual operating cost of US$35- 55/household/year). Filter cloth may not be appropriate Low production capacity10L/day/household Cultural resistance - chlorine taste of the water. Dependence on supply of materials

Advantages of Ceramic Candle Filters Disadvantages- Highly effective against most waterborne pathogens Operate consistently regardless of turbidity No addition of chemicals to the water. Therefore absence of tastes and odours + Easy to use and maintain, + Visual observation of the water quality improvement (turbidity reduction). + High levels of user acceptability. - Low viral removal. - No residual protection, -Relatively high cost if produced in developed countries: - Low production capacity (20L/day, or 0.5-2L/h, depending on the filter and the turbidity of water). - Breakage is possible. - Systems require regular cleaning to restore normal flow rate (each week or two weeks). - Candles must be changed (life expectancy of 6 months to 2 years). © CSIR

Advantages of Ceramic Filter Pots Disadvantages Reduction of diarrhoea 46% in filter users vs non users (Brown 2006) Improved water quality for bacteria and protozoan parasite removal Sustainable and transferable technology Easy to use and maintain Rate of discontinuation of filter use Low virus removal Performance not consistent Low filtration rate insufficient drinking water for an average household. Risk of recontamination of water Advantages of SODIS Disadvantages Proven reduction of viruses, bacteria, and protozoa in water; Proven reduction of diarrheal disease incidence Acceptability to users No cost to the user after obtaining the plastic bottles; Minimal change in taste of the water; and, recontamination is unlikely. need for pretreatment of waters of higher turbidity limited volume of water that can be treated length of time required to treat water; or not reaching T for disinfection if cloudy / cold community motivation and training for users on how to correctly and consistently use SODIS

South African-Zim-Kenyan study ceramic filters © CSIR

Southern African study ceramic candle filters filtration reduced the risk of all types of diarrhoea by approx 80%. The reduction was most marked for bloody diarrhoea. © CSIR

Testing of water at community level At community level, after initial characterising of the water, chemical tests are not necessary for community testing as the chemical quality does not vary significantly over time. Microbiological testing is important to ensure that contamination of the drinking water has not occurred. This can be checked easily making use of a field microbiological test called the H 2 S strip test. Black H 2 S producing bacteria present No H 2 S producing bacteria © CSIR

Sustainability criteria (source Sobsey 2008) TechnologyQuantityQualityEase of use CostSupply chain Overall score Disinfection Coagulation/chlorination SODIS Ceramic filters Biosand filters © CSIR

Conclusion The World Health Organization (WHO) concluded that there was “conclusive evidence that simple, acceptable, low-cost interventions at the household and community level are capable of dramatically improving the microbial quality of household stored water and reducing the risks of diarrheal disease and death” (WHO, 2007). © CSIR