The New Standard for Drinking Water

Table 5

Chemical indicators of quality, which affect the organoleptic properties of drinking water.

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)
Inorganic components
Hydrogen index (pH)	pH unit	6.5–8.5	6.5–8.5
Dry residue (total mineralization) optimal content	mg/dm^3	1000 (1500)*	1000; 100–400
Total hardness, optimal value	mmol/dm^3	7 (10)*	7; 1.5–4.0
Total alkalinity, optimal value	mmol/dm^3	6.5	6.5; 0.5–5.0
Sulfates	mg/dm^3	250 (500)*	150
Chlorides	mg/dm^3	250 (350)*	150
Total iron (Fe)	mg/dm^3	0.2	Absence
Manganese (Mn)	mg/dm^3	0.05	Ditto
Copper (Cu)	mg/dm^3	1.0	“ ”
Zinc (Zn)	mg/dm^3	5.0	“ ”
Calcium (Ca), optimal value	mg/dm^3	100	100; 20–60
Magnesium (Mg), optimal value	mg/dm^3	30	30; 6.0–15
Sodium (Na), optimal value	mg/dm^3	200	200; 20
Potassium (K), optimal value	mg/dm^3	20	20; 2.0–20
Organic components
Methyl-tert-butyl ether	mg/dm^3	0.015	Absence
Oil products	mg/dm^3	0.05	Ditto
Chlorophenols	mg/dm^3	0.0003	“ ”

∗The value in the brackets may be established following the ruling by the Chief State Sanitary Physician in the corresponding area for the specific system of the drinking water supply based on the evaluation of the sanitary-epidemiological state in a town and the technology of drinking water treatment used in a case, when other sources of drinking water supply are inaccessible.