Um, I'm no scientist, but . . .

[badtoworse]

16. The presence of biogenic methane in well water indicates a badly constructed well

So drinking the water would not be advisable. If trace amounts of methane were the only issue, the water should be safe to drink. Biogenic methane would indicate that the well is not properly cased and the water would likely also contain bacteria.

Shallow coal seams are another potential source of methane in groundwater. Coal contains lots of methane and it can seep up into the soil and contaminate ground water.

Keep in mind that the gas bearing shales being fracked are more than 5000 feet underground. If there is methane in the water, I would look for a source much closer to the surface rather than assuming it came from the fracked shale.