I used to work in the water table cleanup business. Mainly we cleaned up DNAPLS - basically heavy petrosludge that seeped out of a leaky oil tank. The D in DNAPL meant the sludge hit the water table (below ground) until it found a ledge or cubby hole to sit on. So that might answer part of your question - with fracking at 7000 feet, the DNAPLS will go down not up.
There are LNAPLs - L is for light - those could be problematic because they rise up until they float across the top of the water table. Most companies are pretty cautious but there are a handful of rogue firms out there basically blowing up rocks at depth to see what happens. It’s a bonanza akin to the gold rush. At a GREAT time for the US too, with China and India adding expotentially to the world energy demand.
Personally I think it would be a good idea for the industry itself to come up with a way to reign in the wildcats most likely to cause headaches for everyone. That would be better than a few bad apples closing off this great opportunity (ala coastal oil drilling or building nuclear power plants).