Population using safe drinking water (%)

Proportion of population using safely managed drinking water services (%)
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Definition:
Population drinking water from an improved source that is accessible on premises, available when needed and free from faecal and priority chemical contamination. Improved water sources include piped water, boreholes or tubewells, protected dug wells, protected springs, rainwater, and packaged or delivered water.

Method of estimation:
The JMP assembles, reviews and assesses national data collected by statistics offices and other relevant institutions including sectoral authorities. Linear regression is used to provide estimates of the population using improved drinking water sources, as well as the proportion with improved water supplies on premises. Regressions are also made to estimate the population using piped water supplies; this is constrained to not exceed the estimate for total improved drinking water sources. The proportion of the population using improved drinking water facilities that accesses those facilities with a collection time of thirty minutes or less is estimated by taking an average of all available data from household surveys and censuses. Separate regressions are made on three service level parameters: (1) the proportion of the population which drinks water from improved water sources which are accessible on premises, (2) the proportion of the population which drinks water from improved water sources which are available when needed (that is, households are able to access sufficient quantities of water when needed), and (3) the proportion of the population which drinks water from improved water sources which are compliant relevant national or local standards (for E. coli, and for arsenic and fluoride if available). In the absence of such standards, reference is made to the WHO Guidelines for Drinking Water Quality. Separate regressions are made for urban and rural areas. The most recent household survey or census available for most countries was typically conducted two to six years ago. The JMP extrapolates regressions for two years beyond the last available data point. Beyond this point the estimates remain unchanged for up to four years unless coverage is below 0.5 per cent or above 99.5 per cent, in which case the line is extended indefinitely. Since the data sources used for different service level parameters may not be the same, it is not always possible to determine which households or populations meet all three of the service level criteria. Instead, safely managed drinking water services are calculated at the urban and rural levels by taking the minimum of the three service level parameters. National estimates are generated as weighted averages of the urban and rural estimates, using population data from the most recent report of the United Nations Population Division. For more information see https://washdata.org/monitoring/methods/estimation-methods Predominant type of statistics: adjusted and predicted.