Domestic Water Quantity, Service, Level and Health, WHO 2003

Summary of requirement for water service level to promote health

Service level	Access measure	Needs met	Level of health concern
No access (quantity collected often below 5 l/c/d)	More than 1000m or 30 minutes total collection time	Consumption – cannot be assured Hygiene – not possible (unless practised at source)	Very high
Basic access (average quantity unlikely to exceed 20 l/c/d)	Between 100 and 1000m or 5 to 30 minutes total collection time	Consumption – should be assured Hygiene – handwashing and basic food hygiene possible; laundry/ bathing difficult to assure unless carried out at source	High
Intermediate access (average quantity about 50 l/c/d)	Water delivered through one tap on-plot (or within 100m or 5 minutes total collection time	Consumption – assured Hygiene – all basic personal and food hygiene assured; laundry and bathing should also be assured	Low
Optimal access (average quantity 100 l/c/d and above)	Water supplied through multiple taps continuously	Consumption – all needs met Hygiene – all needs should be met	Very low

Daily fluid intake reference values in litres per capita (IPCS, 1994)

	Normal conditions	High average temp. 32oC	Moderate activity
Adults	1.0-2.4, average 1.9 (including milk); 1.4 (excluding milk)	2.8-3.4	3.7
Adult male	2	-	-
Adult female	1.4	-	-
Child (10 years)	1.0	-	-

Volumes of water required for hydration

	Volumes (litres/day)
	Average conditions	Manual labour in high temperatures	Total needs in pregnancy/lactation
Female adults	2.2	4.5	4.8 (pregnancy) 5.5 (lactation)
Male adults	2.9	4.5	-
Children	l.0	4.5	-

Percentage reductions in diarrhoeal disease rates attributed to water or excreta
disposal improvements (Esrey et al., 1985)

Type of intervention	Number of studies	Percentage reduction
		Median	Range
All interventions	63	22	0-100
Improvements in water quality	9	16	0-90
Improvements in water availability	17	25	0-100
Improvements in water quality & availability	8	37	0-82
Improvements in excreta disposal	10	22	0-48