Saline ground water discharges to the South Fork Ninnescah River in Pratt and Kingman Counties from the adjacent alluvial aquifer. Electromagnetic terrain surveys in this area indicated that the saline ground water is entering the river in intermittent reaches along the channel. The chloride concentration in the river near Murdock exceeds 250 milligrams per liter 75 percent of the time. During base flow in November 1988, stream discharge increased 67 cubic feet per second, and the chloride concentration increased 360 milligrams per liter from Pratt to the Pratt-Kingman County line. The chloride load to the river along this reach was 82 tons per day. The source of saline water probably is dissolution of salt in the Permian rocks, about 600 feet below land surface. Subsequent subsidence and collapse of Permian rocks into salt-dissolution cavities probably has caused fracturing in overlying Permian rocks. Brine moves upward through the Permian rocks and discharges into the alluvial aquifer. The brine discharge to the alluvium is about 0.7 cubic foot per second. In the area of major saline-water discharge to the river, the fluid-potential levels in the Permian rocks are higher than fluid-potential levels in the alluvial aquifer. Several methods for reducing the saline ground-water discharge to the South Fork Ninnescah River have been considered. The most effective of these methods appears to be interception of brine flow in the Permian rocks by pumping of relief wells. Brine could be disposed by injection into deeper formations, by storage in evaporation reservoirs, or by desalinization.
Additional publication details
USGS Numbered Series
Geohydrology and saline ground-water discharge to the South Fork Ninnescah River in Pratt and Kingman Counties, south-central Kansas
Water-Resources Investigations Report
U.S. Geological Survey ;
U.S.G.S. Earth Science Information Center, Open-File Reports Section [distributor],