The alluvium underlies flood plains and terraces of all streams.
The alluvium may yield as much as 100 gal/min from sands and gravel
along the Tradewater and Pond Rivers. It yields enough water for a modern
domestic supply (more than 500 gal/day) to wells in valleys of the Pond
and Tradewater Rivers and their larger tributaries, but practically
no water to wells in small valleys where it is thin and fine-grained.
Water is hard or very hard and may contain objectionable amounts of
Terrace Gravel Deposits (Qt)
These deposits underlie tops and flanks of hills between elevations
of 420 to 500 feet along the Pond and Green Rivers.
In places these deposits yield enough water for a domestic supply to
dug wells. Water generally is soft and low in dissolved solids, but
may contain objectionable amounts of iron.
McLeansboro Group (Mattoon, Bond, Patoka and Shelburn Formations),
formerly the Sturgis Formation (Ps)
This group forms dissected uplands and ridgetops.
This group yields practically no water except to wells penetrating sandstone.
However, near Hanson and Manitou, some wells intersecting joints produce
enough water for a domestic supply, but may contain hydrogen sulfide.
Water from shallow wells near outcrop areas is hard, and water from
deep wells further from the outcrop areas is generally soft and contains
sodium bicarbonate (in some places in objectionable amounts). Iron may
be present in objectionable amounts. In areas where the Kentucky No.
11 coal has been mined, the sandstone may be dry, or it may yield water
containing iron sulfate.
Carbondale Formation (Pc)
The Carbondale forms dissected uplands and ridgetops.
The Carbondale yields enough water for a modern domestic supply to wells
penetrating sandstone, but yields practically no water to wells penetrating
only shale. Wells are known to produce as much as 30 gal/min. Water
is hard or very hard but otherwise of good quality. The Carbondale yields
either no water or water containing iron sulfate in areas where the
Kentucky No. 9 coal has been mined.
Tradewater Formation (Pt)
The Tradewater underlies dissected uplands and ridgetops. Resistant
sandstone beds in the Tradewater form cliffs.
The Tradewater generally yields only small quantities of water to wells,
however, it may yield enough water for a modern domestic supply to wells
penetrating a sufficient thickness of sandstone. Water is fresh near
outcrops areas but becomes increasingly mineralized with depth.
Caseyville Formation (Pca)
The Caseyville underlies dissected and rolling uplands. Thick sandstone
beds in the Caseyville form cliffs and a major escarpment.
The Caseyville will yield enough water for a modern domestic supply
to most wells penetrating sandstone. Yields of 100 gal/min have been
obtained from wells penetrating thick sections of sandstone. At depth,
the water becomes salty or may have a high sodium bicarbonate content.
Water is hard to very hard and low in dissolved solids. In southwestern
corner of quadrangle wells in small upland areas generally are inadequate.
Generalized areas of underground mining have been compiled for several
important coal beds as part of the U.S. Geological Survey's National
Coal Assessment Program. Using this data, a map was created showing
areas of selected seams in the county.
The U.S. Geological Survey's Hydrologic
Atlas Series, published cooperatively with the Kentucky Geological
Survey, provides hydrologic information for the entire state.
to "Groundwater Resources in Kentucky"