Water Quality Standards

ENVIRONMENT 3 WATER QUALITY CRITERIA & STANDARDS.

Guidelines for drinking water acceptability aspects microbiological aspects chemical aspects radiological aspects

Acceptability aspects a) b) c) d)

physical parameters Turbidity : should be free from turbidity. Color : free from any color. Taste & odour : tasteless & odourless. Temp : cool water decreases the efficiency of treatment.

a) b) c) d)

Inorganic constituents. Chlorides : standard level is 200mg/litre. Hardness : upto 500mg/litre is tolerated. Ammonia : upto 3mg/litre is accepted. ph : acceptable levels are 6.5 to 8.5.

a) iron : 0.3mg/lt

f) Sodium : 200mg/lt is the threshold. g) Sulphate : 270mg/lt is the max level. h) Dissolved oxygen : i) Copper : below 1mg/lt is the optimum level. j) aluminium : 0.2mg/lt is the optimum level.

Microbiological aspects bacteriological indicators a) coliform organisms b) faecal streptococci c) cl. perfringes

biological aspects: i) protozoa : entamoeba, giardia ii) helminths : dracunculus medinensis iii) free living organisms : fungi, algae.

CHEMICAL ASPECTS inorganic constituents in water a) arsenic b) cadmium c) chromium d) cyanide e) flouride f) lead

Other constituents in water a) polynuclear hydrocarbons b) pesticides : ddt, chlordane, lindane.

SURVEILLANCE OF WATER i) sanitary survey : on the spot inspection & evaluation by a qualified person.

ii) bacterilogical surveillance :

Bacteriological surveillance i) PRESUMPTIVE COLIFORM a)Multiple tubetest: b)Membrane filtration technique: ii) DETECTION OF FAECAL STREPTOCOCCI iii) COLONY COUNT : done in nutrient agar