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Kansas Geological Survey, Open-File Rept. 96-1a
Proposed Management Areas--Page 8 of 16

Development of Water Resources of Marginal Quality

Ground-water of marginal quality is defined in this report as ground water with a total dissolved solids concentration that exceeds 1,500 mg/L, but is less than 10,000 mg/L. The distribution of ground-water total dissolved solids in Figure 3 shows that a large part of the usable Dakota aquifer contains ground water of marginal quality. In most instances, the dominant water type is sodium-chloride with chloride concentrations ranging from less than 500 up to nearly 5,000 mg/L. Areas of the Dakota containing these marginal quality ground waters include much of north-central Kansas west of the outcrop belt and portions of northwest Kansas. In these parts of Kansas, the shallower freshwater sources available to users are generally limited to the already fully developed stream-aquifer systems, surface water reservoirs, or to the thinly saturated fingers of the High Plains aquifer. For the municipalities the costs associated with locating, acquiring, and developing these shrinking supplies are escalating with time. Eventually the cost of obtaining a freshwater supply may become so great that other alternative sources will become preferable.

In the future the marginal quality water (certainly up to 5,000 mg/L total dissolved solids) from the Dakota may become a source for high value uses, such as for public water supply and industry. Many of the cities and rural water districts in central Kansas, in particular, will be faced with the choice of using the fresher but very costly waters for their supply or the marginal quality ground waters of the Dakota aquifer as their primary or secondary source of supply. In this regard, the experience of the City of Hays is noteworthy. Faced with a diminishing source of supply from its Smoky Hill valley well field, Hays had to locate and develop an additional supply from the Dakota aquifer to meet its needs. Since 1993, the city has blended ground-water pumped from the Dakota with the fresher ground water pumped from their shallow well fields. The city has also experimented with using the elecrodialysis reverse process (Ionics, Inc.) to remove some of the dissolved solids from the Dakota aquifer.

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Kansas Geological Survey, Dakota Aquifer Program
Original report available from the Kansas Geological Survey.
Electronic version placed online July 1996
Scientific comments to P. Allen Macfarlane
Web comments to webadmin@kgs.ku.edu