Water for people.pdf - WHO Thailand Digital Repository

1 6 8 / C H A L L E N G E S T O L I F E A N D W E L L - B E I N GCities: Competing Needs in an Urban EnvironmentBox 7.1: Singapore Public Utilities Board: reducing Unaccounted-for-WaterWith no rivers or lakes to tap for freshwater, Singapore relieson rainfall collected in its fourteen reservoirs and on importsfrom Malaysia; in the future it will increasingly depend ondesalination. Because of this dependence on outsidesources, the Public Utilities Board has made an effort inrecent years to improve efficiency and reduce waste,especially in the area of Unaccounted-for-Water (UfW).UfW is the difference between the water delivered tothe distribution system and the water sold. It has twobasic components: physical losses, such as water lost frompipes and overflows from tanks, and commercial losses,which include water used but not paid for.Through a consistent monitoring programme, Singaporehas achieved a UfW rate of an impressive 6 percent.Singapore’s UfW reduction programme is based onmetering, audits of commercial water use and leakdetection. The metering programme aims to achieveuniversal metering with high accuracy on all meters byreplacing domestic meters every seven years and industrialmeters every four years, and by measuring and billing forIntegrated Water Resources Management (IWRM) of the basin inwhich each city lies.The health impacts of inadequate provisionUrban areas – life-threatening environmentsThere are several common-sense reasons why urban areas should bebetter served than rural areas. The first is that urban areas providesignificant economies of scale and proximity for the delivery of pipedwater and provision for good-quality sanitation and drainage, so unitcosts are lower. The second is that many cities have a more prosperouseconomic base than rural areas, providing higher average incomes forlarge sections of the population and greater possibilities forgovernments or private utilities to raise revenues for such provision.The third reason is that urban areas concentrate not only peopleand enterprises but also their wastes, and as WHO has recognized,when infrastructure and services are lacking, urban areas are amongthe world’s most life-threatening environments (WHO, 1999a). Thedeficiencies in water and sanitation mean high disease burdens formuch of the population. In addition, in many cities, insufficiencies inprovision for drainage and flood protection expose large sections ofthe population to high levels of risk from flooding and theconsequent spread of disease.water used for firefighting. Singapore has implementedprogrammes to identify consumption patterns and notifycustomers of excessive consumption, identify inconsistentmeter readings, replace faulty meters and set averagewater rates close to the marginal cost of water toencourage careful inspection and evaluation ofunaccounted-for and inefficient use of water. There are alsosubstantial efforts to detect and stop leaks: the systems aretested annually and the surface pipes quarterly, and theseare replaced if more than three breaks a year are reported.As a result of this programme, the number of pipe breakshas decreased from twelve per 100 km/year in 1985 toless than four per 100 km/year in 1992 (Yepes, 1995).Although the annual cost of these investments over athirty-year period works out to US$5.8 million, theprogramme has proven to be cost-effective whenconsidering the current and long-term marginal cost ofwater to Singapore.Source: Prepared for the World Water Assessment Programme (WWAP) by V. Srinivasan,P.-H. Gleick and C. Hunt at the Pacific Institute, 2002.Human contamination from faecal-oral pathogensThe risks of human contamination from faecal-oral diseases vary withdifferent levels of provision for water, sanitation and hygiene (seefigure 5.1 in chapter 5). But one difficulty consists in assessing theprovision for water and sanitation, since even ignoring the variationat each level, it is unclear where to draw the line between‘adequate’ and ‘inadequate’ provision. What is clear, however, is thatthere are quantum health gains from improved service levels of watersupply and sanitation. The transition from a situation of no servicesat all to one with the most basic of services allows the mostsubstantial health gains, followed by those gained from extendingthe services to the individual household. The best health system incities is water piped into everyone’s home with internal plumbingfeeding into bathrooms and kitchens, and with toilets, baths,showers and sinks connected to sewers. This is an accepted standardfor cities in high-income nations and may be achieved or achievablein some cities in middle-income nations (see for instance levels ofprovision in Porto Alegre in Brazil, described in Menegat, 2002).However, in any city in which large sections of the population havevery inadequate provision for water and sanitation and limitedresources, it is inappropriate and not feasible. In this case, thepriority should be to ensure that everyone has ‘improved’ provision,although higher standards can be provided to areas of the city