Section 150(8) in The Coal Mines Regulations, 2017
(8)All such bore-holes referred under sub-regulation (7) shall be drilled sufficiently close to each other to ensure that the advancing face will not accidentally hole through into a working containing water or liquid matter or any material that is likely to flow when wet and shall be constantly maintained at sufficient distance in advance of the working and such distance shall in no case be less than three meters.
