Rapid assessment of drinking-water quality in the - WHO/UNICEF ...

A. Criteria:
1- E. Coli counts shall be no more than 20/100 ml in more than
20% of the tested samples within one year.
2- Turbidity concentration must not exceed (5) five units in any
individual sample.
3- Hydrogen ion concentration must not be less than 6.5 and
must not exceed 8.5 units.
B. Operation Procedures:
Resource operation exploitation must be stopped in any of the
following cases:
1- When any of the two guidelines mentioned in items 2,3 of A
above is exceeded.
And operation of the resource shall not be resumed unless the
results of all samples have met the guidelines mentioned
above for two consecutive days.
2- If the E. Coli counts amount to 50/100 ml in any single
sample.
And operation of the resource shall not be resumed unless the
E. Coli counts are reduced to less than 50/100 ml in all
samples tested for three consecutive days, at 2 samples / day
minimum and at least at two hours intervals between one
sample, and the other.
3- If the number of samples that contain more than 20 E. Coli
per 100 ml exceeded 20% of the samples assumed to the
tested within one year (except for the samples tested during
the suspension period).
Operation of the resource shall not be resumed unless
treatment station including necessary treatment processes is
established according to guidelines stated for categories two
or three of water resources.
3-2 Second Category:
These are water sources that can be used for drinking
purposes provided that they are subjected to both filtration
and disinfection processes.
A. Criteria:
These are the resources in which E. Coli counts exceed
20/100 ml in more than 20% of the samples and do not
exceed 2000/100 in more than 20% of the tested samples
within one year.
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