WATER SUPPLY

Murray BiedlerJuly 09, 2012

WATER NEEDSDrinking

Food Prep

Hygiene / Washing

Agric / Stock

CHARACTERISTICSof

WATER SUPPLY

Quantity Quality Access and Sources Treatment

Not static… constantly changing

WATER QUANTITY

Europe 150-litres/p/day average Emergencies

• 20-litres/p/day minimum• 5-litres/p/day: opening of emergency• Health centre: 1-2 litres/consultation• Hospital: 40-60 litres/patient/day (100 for

surgery)• Therapeutic feeding centre: 30 litres / child / day• Cattle: 30 l/animal/day • Small animals: 5 l/animal/day

WATER QUALITY

Bacteriological quality linked to:• Faecal contamination indicative of

pathogens (e.g. cholera or typhoid) (rapid assessment in field)

Chemical quality linked to:• Geological surroundings, agricultural or

other industrial/commercial activities (rapid assessment difficult lab required)

WATER QUALITY

Good Quality: Contains no pathogens Low concentration of toxic products Clear (low turbidity)

Is not too salty or mineralized Colour, odour and taste acceptable

WATER ACCESS:CHALLENGES

Time

Cost

Distance & Security

WATER ACESS: SOURCES

Surface water• rivers, lakes, ponds

(access seasonal) Ground water

• Difficult access but can be better quality

Precipitation• Seasonal: rain, snow,

fog capture

WATER ACCESS: SURFACE

On site pumps to storage / tower

Gravity network, pipes & taps

WATER ACCESS: GROUNDWATER

Hand-dug wells: hand pumps, buckets

Boreholes (shallow &

deep) pumps: hand, motor, solar, wind…

WATER ACCESS: SPRINGS

Springs: on site pumps or gravity into networks, pipes & taps

WATER ACCESS: PRECIPITATION

Rainwater collection gravity to tanks networks, pipes & taps

WATER ACCESS: STORAGE Storage provides

availability on regular basis

Storage tanks provide:• Treatment of large

volumes• Pressure with gravity

Dams: surface and subsurface; seasonal & precipitation constraints

WATER ACCESS DISTRIBUTION 1 tap/200 persons for

displaced populations Health facilities: taps for

staff, patients & visitors

Container distribution

WATER TREATMENT

Chlorination simplest & most efficient way to kill micro-organisms

Residual chlorine necessary to attack further contaminations

Chlorination becomes inefficient if the water is too dirty or turbid

SEDIMENTATION & FILTRATION

Water stored until suspended particles settle Water can be filtered with sand or other

designed materials Coagulation-flocculation for heavy turbidity

using chemicals (e.g.ferric chloride or aluminium sulphate)

DOMESTIC STORAGE

Container

lid or top (e.g: jerry can) or a narrow opening(transport)kept clean regularly dosed for residual chlorine(storage)

MAIN ISSUES TO BE CONSIDERED

NEEDS ANALYSIS

POTENTIAL

SOURCES

TECHNICAL

OPTIONS

ENSURING

QUALITY

SANITATION AND

HYGIENE

AVAILABLE

QUANTITY

ADAPTED

WATER SUPPLY