Water for people.pdf - WHO Thailand Digital Repository

C I T I E S : C O M P E T I N G N E E D S I N A N U R B A N E N V I R O N M E N T / 1 6 7lives of at least 100 million slum dwellers – will achieve no morethan previous commitments made by governments and internationalagencies.There is, however, an add-on value of setting such goals on arelatively short-term basis and within a minimalist view ofdevelopment: in retrospect, without the IDWSSD goals, the statusof water and sanitation in the world would have been even worse.In high-income nations, the need for all urban households to havesafe, regular piped water supplies to their home, internal plumbing andtheir own sanitary toilet is unquestioned. These can be set as thestandard for which universal provision is possible. But in lower-incomenations, where universal provision to such a standard is not possible,other standards have to be set. From a public health perspective, it isbetter to provide a whole city’s population with safe water supplies totaps within 50 metres of their home than to provide only the richest20 percent of households with water piped to their home. The GlobalWater Supply and Sanitation 2000 Assessment Report suggests that‘reasonable access’ for water should be broadly defined as ‘theavailability of at least 20 litres per person per day from a source withinone kilometre of the user’s dwelling’. For most urban settings, distancealone does not provide an appropriate standard; population density isa critical modulator. While in a sparsely populated rural area, a onekilometredistance may indeed provide reasonable access, this is mostunlikely to be the case for a high-density squatter settlement with apopulation of 100,000. Furthermore, standards for water provisionshould also consider the regularity of the supply alongside such issuesas water quality and price. In recognition of the fact that assessmentsat all levels of access to water and sanitation need to account formultiple criteria, the WHO/UNICEF JMP is constantly refining existingcriteria and developing and testing new ones. Future assessmentsshould be increasingly sensitive and specific, and yield results that willfacilitate informed decision-making.Unfortunately, there are few detailed datasets available on thequality of provision for water and sanitation in most of the world’scities. Most of the data upon which national or global surveys ofprovision rely are drawn from censuses or household surveys that donot ask most of the critical questions regarding the adequacy ofprovision. In addition, the criteria used in most such censuses orhousehold surveys for assessing adequacy do not address importantdifferences between rural and urban contexts. Indeed, health risksfrom using toilets in many urban settings may be more linked to thenumber of people sharing each toilet than to the kind of toilet used(Benneh et al., 1993), but data are often not collected on theextent of toilet sharing. This explains why global assessments ofwater and sanitation provision for the world’s urban (and rural)populations are not able to measure the proportion of people withaccess to ‘safe and sufficient’ water and ‘safe and convenient’sanitation, but only the proportion with access to ‘improved’ sourcesof water and ‘improved’ sanitation. Reviewing the quality of waterand sanitation provision in the world’s cities shows a continuumbetween those with very high quality to those with little or none.Basically, there are three levels of provision.■ In high-income countries, there is more or less universalprovision of advanced water and sanitation facilities and othercity water services, most of which are provided by public sectorutilities, although increasing use is being made of private sectorprovision. The main challenges revolve around prevention ofmicrobial and chemical contamination of water distributionsystems, optimizing the efficiency of utility operation both ineconomic and in ecological terms, dealing with issues of assetrenewal and management of residuals from water treatment, andensuring that the impact of effluents from wastewaterdischarges on receiving waters remains within acceptable levels.■ In middle-income countries, a great deal of water and sanitationinfrastructure exists but it is often in poor condition. The servicedelivery systems are frequently underfunded, poorly managedand in a poor state of maintenance with high levels of waterleakage, and inadequate wastewater treatment. Here the mostpressing issues are usually related to improving efficiency,infrastructure maintenance, renewal and extension, pricing andrevenue collection, and more effective supervision andenforcement of regulations on industrial pollutants. Governmentsare beginning to take steps to address these issues, especially inlarger cities (see box 7.1).■ Lower-income countries have particularly difficult problems. Theyhave less water and sanitation infrastructure than high- andmiddle-income countries. Likewise, their institutions andmanagement systems are generally underdeveloped, and theiroverall capacity to deliver a reasonable water and sanitationservice is very low. Big cities generally have some water andsanitation infrastructure in their central areas, and this is, inmany cases, being improved and expanded by the introduction ofprivate concessionaires or improved public utility operations.However, in many peri-urban areas of large cities and in mostsmaller urban centres, water and sanitation infrastructure is verylimited, and there are problems with industrial pollution – oftendifficult to control as they stem from many small-scaleoperations. The overall result is widespread microbial andchemical pollution of water sources in and around the cities.In each of these three situations, cities face the challenges ofdeveloping integrated urban water management systems appropriateto their needs and capacities, but nested within the system of