Drinking Water

Waste water and ground water must be treated to make the water potable or sate to drink.

Stages in water treatment 

1) Sediimentation- large insolule particles sink to the otton of a tank 

2) filtration-small insoluble particles are removed by filtering through beds of sand 

3) Chlorination- chlorine gas is bubbled from the water to kill microbes.

Drinking water  

Potable drinking water must have:

• low levels of contaminating substances 
• low levels of microbes.

Fresh water can come from reservoirs, lakes and rivers. it is likely to contain: 

• objects such as leaves and twigs 
• insolubes solids such as particles of soil
• …