The correct options are
A It affects irrigation water.
B It causes death of aquatic life.
C It spreads water-borne diseases and epidemics.
D It disrupts the natural food chain.
The important effects of water pollution are: It spreads water-borne diseases and epidemics like cholera, typhoid, diarhea, jaundice, etc. It also causes death of aquatic life, affects irrigation water and on agricultural crops, nature and features of water, causes disruption of natural food chain, etc.