Actually we kinda do. Fracking has been used for several decades. Drillers inject a liquid (mostly water) , thousands of feet below the water table, in order to fracture rock formations holding oil. The videos you see of people setting fire to water coming out of faucets has nothing to do with fracking, and no one has ever found a legitimate link between those injections and contaminated ground water.
In fact, the worse environmental damage done to ground water was a pollutiin control chemical California mandated refiners add to gasoline. That stuff really did leech into ground water, from the surface..