The New Standard for Drinking Water

Table 1

Microbiological indicators of drinking water quality.

Indicator	Measurement units	Norm, not more than
		Water of systems of centralized drinking water supply	Water of uncentralized drinking water supply additionally purified (unbottled, bottled)
Number of bacteria in 1 cm^3 of water under study (TMN) at 37°C	CFU/cm^3	100^1∗	20^1∗
Number of bacteria in 1 cm^3 of water under study (TMN) at 22°C	CFU/cm^3	100^1∗	20^1∗
Number of bacteria of the colibacillus group (coliform microorganisms) in 1 dm^3 of water under study (BCG index)	CFU/dm^3	3^2∗	Absence^2∗
Number of thermostable colibacillus (fecal coliform—FC index) in 100 cm^3 of water under study	CFU/100 cm^3	Absence^3∗	Absence^3∗
Number of pathogenic microorganisms in 1 dm^3 of water under study	CFU/dm^3	Ditto^3∗	Ditto^3∗
Number of coliphages in 1 dm^3 of water under study	PFU/dm^3	“ ”	“ ”
Spores of sulfate-reducing clostridia	Presence (amount)/20 cm^3	Absence^4∗	Absence^4∗
Blue pus bacillus (Pseudomonas aeruginosa)	CFU/dm^3	Not determined	Absence

1∗An excess of the norm shall not be allowed for 95% of water sample in the water supply network that is under investigation during the year.
2∗An excess of the norm shall not be allowed for 98% of water samples in the water supply network that is under investigation during the year. In the event the BCG index is exceeded at the stage of colony identification investigations shall be carried out for the presence of fecal coliforms.
3∗In the event of the presence of coliform bacteria or coliphages in a water sample their amount shall be immediately determined in repeatedly taken water samples. If in these samples generally coliform bacteria are found in the amount of >2/100³ and (or) thermostable coliform bacteria and (or) coliphages, pathogenic bacteria of the colibacillus group and (or) enteroviruses shall be determined. The investigation of drinking water for the presence of pathogenic bacteria of the colibacillus group and enteroviruses shall also be carried out following the decision of the organs of sanitary supervision in the event of the emergence of the epidemic situation.
4∗The control shall be exercised at the outlet from the drinking water conditioning station in the case of using surface sources of water supply or underground ones, which have the hydraulic connection with the surface water body; during the transition period annually the index of the spores of sulfate-reducing clostridia with the norm “absence/20 cm³” shall be controlled.