Saturday, March 31, 2007

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

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