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Sub-unit Survey--Eastern Highland Rim (SUS1)

Map of LTEN study unit with Eastern Highland Rim highlighted


The first subunit survey  was conducted in the Eastern Highland Rim during June and July 1999. The Eastern Highland Rim was selected because ground-water use for both public and domestic water supply is highest in this subunit and it has the largest subunit population. The Mississippian carbonate aquifer that supplies ground water in this subunit is a karst aquifer characterized by ground-water flow through dissolution openings along bedding planes, joints, and fractures. Regolith of varying thickness (generally between 20 to 100 feet) overlies bedrock and increases storage in the aquifer. It is an unconfined aquifer and the depth to water is shallow. Ground-water flow paths typically are short and ground water discharges to streams and springs. The potential for contamination from surface activities is high given these aquifer characteristics. 


Thirty-two wells were sampled for this subunit survey.  Three of these were public-supply wells.  Of the domestic wells sampled, about a third were in use for supplying drinking water.  Well depths ranged from about 40 to 150 feet below land surface; the average depth was 90 feet. Water levels generally were less than 60 feet below land surface.  These wells were sampled for major and trace inorganic constituents, nutrients, pesticides, volatile organic compounds, radon, and radium (see list of constituents).  A subset of wells was sampled for chlorofluorocarbon analysis to estimate a ground-water recharge age.

Last modified: Wed Mar 29 16:13:13 2000