Drinking Water

Drinking water is water intended for human consumption that is safe, clean, and free from harmful contaminants. Quality is governed by standards such as the Bureau of Indian Standards (IS 10500:2012) and World Health Organization guidelines. 

Sources of Drinking Water 

1. Surface Water 

• Rivers, lakes, reservoirs, ponds  

• More prone to contamination from sewage and industrial discharge  

• Requires extensive treatment before use 

2. Groundwater 

• Borewells, tube wells, open wells  

• Generally clearer but may contain dissolved minerals (fluoride, arsenic, iron)  

• Widely used in rural and urban India  

3. Rainwater 

• Harvested from rooftops or catchment systems  

• Low in dissolved salts but may pick up contaminants from air and surfaces  

• Requires filtration and disinfection  

4. Municipal (Tap Water) 

• Treated water supplied by local authorities  

• Typically sourced from surface or groundwater and treated centrally  

• Quality depends on distribution system maintenance  

5. Packaged Drinking Water 

• Bottled water and jar water  

• Processed through RO, UV, ozonation  

• Must comply with BIS certification (ISI mark)  

6. Desalinated Water 

• Seawater treated by reverse osmosis  

• Used in coastal regions  

• Low mineral content; may require remineralization  

Key Quality Parameters 

Physical 

• Colour, Turbidity, Odour, Taste, TDS  

Chemical 

• pH (6.5–8.5)  

• Hardness, Alkalinity  

• Chloride, Sulphate  

• Nitrate, Fluoride  

• Heavy Metals (Pb, As, Cd, Hg)  

Microbiological 

• Total Coliforms  

• Escherichia coli  

• Faecal Streptococci  

Sources of Contamination 

• Natural (geological minerals)  

• Industrial waste  

• Agricultural runoff (pesticides, fertilizers)  

• Sewage and domestic waste

Importance of Testing 

• Ensures safety and compliance  

• Prevents water-borne diseases  

• Critical for the food industry, exports, and public health.