Need soution for borewell water foaming and with bad odour


We had a borewell dug almost 10 years ago. All these years it was working fine. All of sudden from past 2 week,s the Borewell water seems to be foaming and has a bad odour. I need your assistance to solve this as we are facing problems due to the unavailability of any other source of water. Can you please suggest some local office or help center in Bangalore where I can find help to my problem?