There are two major areas to consider with wells and natural water supplies. One alleged cause of well problems commonly claimed is from rock fracturing. To cause fracturing or shifting of rock strata, blasting operations must be within close proximity to the well. Many people believe that if the energy can be felt then it is also fracturing the rock at that distance. This is not the case. Fracturing of the rock takes place within about 10 feet of the drilled borehole. Outside of that radius, the energy that remains is elastic in nature and is felt as ground vibration. For the overall blast the fracture zone is a bit bigger but not past a few hundred feet, depending also upon the size of the blast. This is the reason drillers put boreholes on a specific spacing pattern and use multiple holes in a blast. In other words, the fracturing of the rock only occurs within a very small area around the drilled blast hole.
For the vibration component of a blast, well studies dealing with ground vibration produced from surface mining provide solid research. Numerous studies were developed to analyze the relationship between ground vibrations, well components and the aquifer. These studies all concluded that vibration damage to wells and well components requires much higher velocities than the regulated levels currently set by state and local governments. Research shows that wells are resilient to vibration and levels at the surface are reduced at the depth of the well. This precludes damage to submerged pumps and plumbing and the well casing.