(a)Eutrophication is a natural process observed in lakes and tanks where rich growth of micro-organisms consumes much of dissolved oxygen, depriving other organisms. It is generally found at bottom layers of deep lakes. Addition of excessive plant nutrients increases Eutrophication and is harmful to fish and other aquatic life.
(b) Foam formation in waters by soaps, detergents and alkalies.
(c) Impairment of taste and unpleasant odours in water.
(d) Turbidity which makes water unfit for drinking and industrial purpose.
(e) Inorganic nitrates and phosphates stimulate excessive plant growth in lake and reservoirs.
