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Slide 3

Some strata hold groundwater we would call good groundwater.  Water wells are drilled to the good groundwater in these strata.  These are sometimes called “freshwater” rock strata.  When a good groundwater strata pokes out the side of a hillside etc. it may cause a spring.

Other water strata hold water that contains sulphur, salt etc. – bad groundwater.

The good water is isolated from bad groundwater, by rock strata that is impervious to water passing through it.  It keeps the bad groundwater from mixing with and ruining the good groundwater.

In West Virginia the good groundwater is usually closer to the surface than the bad groundwater (not the case everywhere) so it can be accessed by relatively shallow water wells.

If even your shallow water is bad, look around for old orphaned oil or gas wells in the area.  They may not have been plugged or may not have been plugged properly and may be allowing the bad ground water into the good groundwater.  There is very, very limited money for the State to plug problem orphaned gas and oil wells.

Old coal mines etc. can also ruin good groundwater.

The gas bearing rock strata is porous/permeable.  This has allowed the gas migrating upward over the eons to collect in the microscopic spaces in the rock.  The gas cannot migrate higher because the next rock strata up is not porous/permeable.  That next layer forms a seal, like the rock between the good and bad groundwater strata, that keeps the gas from migrating higher and causes a pool of gas in the gas bearing strata.