I had previously dirilled a 4.5 inch borewell in my site. This well got contaminated by sewage water. The contamination happened after getting 2 months of clean water from it. This well is dug in Bangalore for a depth of 150ft and PVC casing for 40 ft.

We had our sewage line just beside it and our neighbour has built a new house adjacent to our house. His sewage line also passes next to borewell. The borewell is in between our sewage and neighbour sewage lines. Both lines are seperated by roughly of 2ft on either side of borewell.

After the contamination of the borewell I stoped its usage. Now I have demolished my part of house any my sewage lines are not in use. While I consulted a water diviner he showed a point for new borewell. This point was roughly 6ft away from previous one. This point was right on the same striaght line with previous bore well.

I got drilling done for new point with casing for 40 ft  to a depth of 350ft with 6inch drill. The driller said the both borewells got linked at 80ft. He said the air pressure applied here to dig the new well made the water to rise in the adjacent previous bore well. So he concluded the linkage was present.

Now my doubt is, since the borewells are linked does the contamination flow to the new borewell from previous well. I have stopped using my sewage lines and i am planning to shift my sewage lines to opposite side of site about 25 feet away from borewell. While I can shift mine my neighbours remain in the same place about 1ft away from previous borewell.

The borewell contractor says there will not be any trouble from neighbours sewage line because his lines are new and cannot leak. The reason for this non leakage assurance is the use of PVC pipes. While I agree with his argument I suspect the flow of polluted water into new well at a later date.

Is my suspision right?

Will the new bore well get contaminated from the previous borewells linkage?

I have not drawn water from new well as I have not installed pump for it.

What should I do to prevent previous pollution entring to new borewell? I am prepared to close the old borewell by filling it with mud and small pebble stones.will the closure be a permanent solution for it. Kindly help me in this connection

Please see the attached illustration of location of borewells and sewage lines to get a clear idea of the