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

what have been mentioned in the second category, provided
that the treatment processes as a whole shall guarantee
elimination of viruses at 99.99% (4 logarithms), and
cryptosporidium at 99.99% (4 logarithms).
C. Operation procedures:
Resource operation shall be stopped if E. Coli counts
exceeded 2000/ 100 ml in any sample.
And operation of the resource shall not be resumed, unless
the results of all tested samples within the suspension period
were less than 20000/ 100 ml for three consecutive days, at 2
samples per day minimum, with at least two hours intervals
between are sample and the other.
4- General Rules:
1. In case no technical capacity for E. Coli test is available, then
the total Thermotolerant coliform count (TTCC) shall be
applied with the same guidelines.
2. Water resources classified within these guidelines shall be
subjected to quality control at two samples per week
minimum for raw water prior to treatment.
3. The owner of the water resource shall submit the necessary
documents to the official water monitoring party, to ensure
the efficiency of the treatment units proposed or used.
References
USEPA (1990). EPA guidance manual for compliance with filtration and disinfection
requirement. Washington DC: US Environmental Protection Agency.
WHO (1997). Guidelines for drinking-water quality, second edition. Geneva: World Health
Organization.
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