Below is a list of the procedures for purifying drinking water:
1) The uptake of water from surface waters or groundwater and storage in reservoirs.
2) Rapid sand filtration or sometimes microfiltration in drum filters.
b: Incorporation of chemicals
3) pH alteration through the inclusion of calcium oxide and sodium hydroxide.
4) FeCl3 add-on to cause flocculation for removing humic acids and suspended particulate matter, if needed using the inclusion of a supplementary flocculation support.
5) Softening in a reservoir, using natural aeration or with sodium hydroxide, on to 8,5 oD. That is not always necessary.
c: Natural filtration
7) Disinfection with ozone or sodium hypochlorite. Ozonation will be favored, because Ozone not only kills viruses and bacteria; odour and taste properties also improve and breaks down micro pollutants.
e: Excellent filtration
8) Slow sand (media) filtration for removing the remaining turbidity and dangerous bacteria. Sand filters are back washed with atmosphere and water daily.
9) Effective carbon filtration for additional removal of matter changing taste and odour and lingering micropollutants. This takes place when water streams by way of a granular activated carbon layer in a filter. As a result of silting up backwash is often needed and reactivation of an active carbon filter needs to be performed once annually.
f: Preservation and storage
10) Summation of 0.3 mg/L sodium hypochlorite to ensure the preservation of the got quality. Not all businesses chlorinate drinking water. The water will be distributed through distribution pumps and pipelines.
11) Aeration for restoration oxygen supply of the water before storage(This is not consistently used).
12) Lingering water may be kept in drinking water reservoirs.