Globally there are standards developed for parameters to be tested in water in order to assess suitability for drinking. In India, BIS has issued IS 10500:2012 wherein desirable and permissible limits are specified for specific chemical and biological characteristics of water which should be within permissible limits for the water to be suitable for drinking purpose.

Major parameters include pH, Total Dissolved Solids, Total Suspended Solids, Mineral Oil, Hardness, Alkalinity, Chlorides, Fluorides, toxic metals, Pesticides residue, Total Coliforms and E. coli bacteria.

Usually it takes 2–3 working days for chemical tests including organoleptic and physical parameters (Table 1), general parameters (Table 2), and toxic substances (Table 3), while tests for bacteriological quality (Table 6) usually take 7 working days. For testing pesticides residue, about 7 working days are required.

At household level, drinking water received through community water supply system or fetched through borewells should be tested at least once in three months and specifically during monsoon as there are chances of bacterial contamination.

At industry level, it is recommended to test drinking water of all dispensers at least once in three months.

Yes, ponds, lakes, khadis and rivers serve multiple uses – water for bathing, washing, fishing and aquaculture, irrigation and sometimes drinking water. Therefore, water from these bodies should be tested regularly for early detection of toxicity and bacterial contamination.