Groundwater Availability
 

Alluvium (Qa), Glacial Sediments (Qg)
Topography
These sediments form the floodplains and terraces of the Ohio and Licking River Valleys and tributaries. Highest terraces are about 100 feet above normal pool level of the Ohio River. The sediments are too thin in tributary valleys to have distinctive topography.

Hydrology
These unconsolidated materials yield moderate to large quantities of water to drilled wells in the Ohio River valley, according to thickness and texture of the valley fill and type of well 200 to 500 gallons per minute to ordinary tubular wells and as much as 1,000 gallons per minute to gravel-packed wells. Yields are more than 3 million gallons per day during the summer in the Covington-Newport area of the valley. The sediments yield little water from fine-grained material. Drilled wells in the Licking River Valley yield small to moderate amounts of water; most wells yield more than 500 gallons per day. Water is hard and near the valley walls of the Ohio and Licking Rivers may have a high iron content. Wells that penetrate the alluvium and enter bedrock obtain little additional water, and this water may contain objectionable amounts of salt or hydrogen sulfide.

Bull Fork Formation (Ob)
Topography
The Bull Fork forms gently to moderately rolling uplands where limestone predominates; it is more dissected where shale predominates.

Hydrology
The Bull Fork yields 100 to 500 gallons per day to wells in valleys or on broad ridges, but almost no water to drilled wells on narrow ridges or hilltops. It does yield water to dug wells and to small springs. Water is hard and of good quality.

Grant Lake Limestone/Fairview Formation (Oaf)
Topography
These formations create gently to moderately rolling uplands away from major streams such as the Ohio and Licking Rivers. They form steep, dissected slopes along large streams, with ledges of thick limestone beds on steep hillsides and bluffs, and moderately dissected uplands where shale content increases. Streams in uplands produce broad, flat valleys where thick limestone beds are present, and may have small sinkholes with minor underground drainage. Low hills on uplands also may be capped by thick limestone beds. The lower part forms broad, flat ridges between steep-sided valleys cut into the underlying shale of the Kope Formation.

Hydrology
These rocks yield 100 to 500 gallons per day to drilled wells in valley bottoms and along streams on uplands; they yield more than 500 gallons per day from thick limestone beds in broad valley bottoms, and almost no water to wells on hillsides or hilltops. They may yield some water to dug wells on ridgetops, and some water to small springs. Small perennial springs are in limestone in the lower Grant Lake Limestone. Water is hard and in valley bottoms may contain salt or hydrogen sulfide. The relatively impermeable shale prevents circulation of large quantities of groundwater in joints and bedding-plane openings of underlying limestone. As a result, the limestone beds have few solutionally enlarged openings, and little water is available to wells and springs. Near the base of the Grant Lake there is 25 feet or more of limestone with small amounts of shale (Bellevue Limestone Member), however. Where this limestone occurs at and below stream level in valley bottoms or along streams on the uplands, fractures and bedding-plane openings have been enlarged by solution; many small springs flow from outcrops, and some drilled wells along streams yield more than 500 gallons per day.

Kope Formation (Okc)
Topography
The Kope forms rugged, much-dissected topography of long, narrow, steep-sided ridges and narrow, winding V-shaped valleys with dendritic drainage pattern. Steep slopes are littered with thin limestone slabs that remain as shale erodes and washes away. The contrast with less-rugged upland surfaces of adjacent areas is marked, except near major streams, where the change is masked by dissection.

Hydrology
The Kope yields 100 to 500 gallons per day to drilled wells in valley bottoms along large streams, but almost no water to drilled wells on hillsides or ridgetops. It does yield water to small springs and seeps. Water is hard in valley bottoms, and may contain salt or hydrogen sulfide. Shale units have small, poorly connected openings that allow passage of only small quantities of water, restricting yields to wells and springs and preventing recharge to underlying rocks. The few thick limestone beds may yield water to small springs. On ridgetops, shale impedes downward percolation of water and supports water in the lower part of the soil and in a weathered-rock zone just beneath the soil. High up on the sides of many ridges is a zone of seeps and small springs. Where the Grant Lake caps the ridges, the zone is generally near or at the contact with the Kope Formation. Drilled wells on these ridges obtain a little water at the contact between soil and bedrock, but rarely at greater depths; if water is found at depth, it is mainly in small quantities and of poor quality. Dug wells, with large wall areas, are better suited for obtaining water from these bodies of water; however, many go dry in late summer and fall.

The U.S. Geological Survey's Hydrologic Atlas Series, published cooperatively with the Kentucky Geological Survey, provides hydrologic information for the entire state. Atlases covering Campbell County are: HA-15, HA-94, HA-98.

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