Alluvium forms floodplains along the larger streams.
Most wells in the alluvium are inadequate for a domestic supply.
Caseyville Formation (Pca)
The Caseyville underlies rolling uplands. Thick sandstone beds form
dissected uplands and cliffs.
Yields of 60 gallons per minute have been obtained from thick sandstone beds. The
Caseyville will yield enough water for a modern domestic supply to most
wells penetrating sandstone. At depth, the water becomes salty or may
have a high sodium bicarbonate content. Electric logs indicate that
moderately mineralized water may be obtained locally from this formation
at depths of 1,200 feet.
Menard Limestone, Waltersburg Formation, Vienna Limestone, Tar Springs
These formations underlie uplands. Thin sandstone beds form small benches
These rocks yield almost no water to wells.
Glen Dean Limestone, Hardinsburg Sandstone (Mcl)
These formations underlie gently rolling to flat uplands. The limestones
form steep slopes above benches of sandstone. The sandstones form small,
discontinuous benches on hillsides.
Most wells in upland areas are inadequate for a domestic supply, yielding
little or no water.
Golconda Formation (Haney Limestone, Big Clifty Sandstone, Beech
Creek Limestone Members) (Mcl)
The limestone underlies gently rolling to flat uplands, and forms bluffs
near heads of valleys. The Big Clifty Sandstone caps the Dripping Springs
Escarpment, several hundred feet high.
Deep wells that penetrate the sandstone formations near perennial stream
level may produce enough for a domestic supply (more than 500 gallons
per day). Close to outcrop areas, particularly near major escarpments,
yields from perched water bodies generally are low and not dependable.
Minor spring horizons occur on discontinuous layers of shale near the
base of the sandstones. The most conspicuous springs are those that
discharge from the base of the Big Clifty Sandstone. These are the dripping
springsof the Dripping Springs Escarpment. Many of these springs go
dry during the late fall and summer, and very few are adequate for a
domestic supply. Limestone formations yield small to adequate supplies
from solution openings. In lowland areas bordering streams, some wells
produce enough for a domestic supply. Many springs occur at the base
of the limestones where they crop out on escarpments and hillsides.
Adjacent to large upland areas, flows are as much as 250 gallons per
minute and low flows from some springs are more than 5 gallons per minute.
Girkin Formation (Paint Creek Limestone, Bethel Sandstone, and Renault
The Girkin forms the lower part of the Dripping Springs Escarpment.
The lower part of the Girkin underlies rolling karst areas near the
base of the escarpment. The Girkin contains many large sinks into which
the overlying sandstone has collapsed. The upper passages of the Mammoth
Cave system lie within the lower Girkin Formation.
Most wells in upland areas are inadequate for domestic use; however,
some wells yield enough water for a domestic supply (more than 500 gallons
per day) from solution openings. Some wells produce more than 5 gallons
per minute from large solution openings. Near outcrop areas, particularly
near major escarpments, yields generally are inadequate during dry periods.
Many springs occur at the base of the limestones where they crop out
on escarpments and hillsides. Adjacent to large upland areas, flows
are as much as 250 gallons per minute and low flows more than 5 gallons
per minute from some springs.
Ste. Genevieve Limestone (Mgl)
The Ste. Genevieve underlies rolling and dissected karst areas. Part
of the caverns of Mammoth Cave are developed in this formation.
The Ste. Genevieve yields more than 50 gallons per minute to wells from
large solution openings in karst areas. Most wells penetrate solution
openings, but in areas high above perennial streams, these solution
openings are dry in late summer and fall, and many wells are inadequate.
Wells that do not intersect karst conduits generally are inadequate
for domestic use. Springs having low flows ranging from less than 10
gallons per minute to more than 1,500 gallons per minute occur at or
near stream level. Smaller springs discharge from perched water bodies
in upland area, but many go dry during late summer and fall.
St. Louis Limestone (Mgl)
The St. Louis underlies rolling karst areas, but commonly has less relief
than karst in areas underlain by the Ste. Genevieve Limestone.
The St. Louis yields more than 50 gallons per minute to wells from large
openings in karst areas. Most wells penetrate some solution openings,
but high above perennial streams, yields are often inadequate for domestic
supply. Yields of wells encountering solution openings close to major
streams are large, but most wells near major streams are inadequate.
A major spring horizon has many springs flowing several hundred to several
thousand gallons a minute.
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"