Hi,

Surface Water ,  is the water which you can easily found on the surface of lakes, ponds, oceans, river etc. It is just same as its name. Now, as this water is present on the surface, so this water contains many impurities caused by direct expose to the environment. So, this water is not used in drinking purposes normally. On the other hand, ground water is the water that is found deep inside ground. We get this water using some motors, pumps etc. Usually this water is safe for drinking because it gets purified by the bed of rocks present inside the ground.

Degradation of water is caused by many ways.

• Industrial waste
• mining works
• wastage or overuse of water
• no proper maintenance of sewage system

Hope it helps.