Water Quality Standards:
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< 10 CFU / 100 ml. at point of delivery ( unchlorinated water ).
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≥ 0,2 - 0,5 mg./ l. FRC at point of consumption ( chlorinated water ).
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Turbidity of less than 5 NTU.
When commissioning a new water source, test the water for :
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Bacteriological parameters,
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Physicochemical parameters.
Do this before and after local seasonal fluctuations.
Do not neglect the analysis of chemical parameters ( such as arsenic and fluoride levels ) that can lead to long-term health issues.
Faecal coliform bacteria ( > 99 % of which are E.coli ) indicate the level of human and animal waste contamination in water and possible presence of other harmful pathogens.
If any coliforms are present, then treat the water.
Even if E.coli is not found, water is prone to recontamination without a residual disinfectant.
Where water is chlorinated ( prior to distribution of household-level treatment ) carry out spot checks in households by measuring FRC and treat where necessary.
The frequency of water delivery, temperature and length of time water is stored, all affect household FRC measurements ( chlorine dissipation ).
