State Water Resources Research Institute Program
Project ID: 2006KS50B
Title: Assessment of Seasonal, Pumping Induced Water Quality Changes in the Ozark Plateaus Aquifer System, Southeast Kansas and Southwest Missouri -- Year 2
Project Type: Research
Start Date: 3/01/2006
End Date: 2/28/2008
Congressional District: 2nd
Focus Categories: None
Keywords: Ozark Plateaus aquifer system, Springfield Plateau aquifer system, Ozard aquifer, water quality, pumping stress
Principal Investigators: MacFarlane, Peter Allen (Kansas Geological Survey); Ghijsen, Rudolf T
Federal Funds: $ 24,990
Non-Federal Matching Funds: $ 61,476
Abstract: The Ozark Plateaus aquifer system has been and continues to be the primary source of water for the residents of the Tri-State region, which includes portions of southeastern Kansas, southwestern Missouri, and northeastern Oklahoma. Recent concerns have been raised by the Kansas water agencies and the Tri-State Coalition that the available supply from the Ozark aquifer may become inadequate, rendered unusable, or require additional water treatment in the near future because or future overdevelopment. Many southeast Kansas and southwest Missouri water supplies withdraw water from a 40-60-km wide transition zone in the Ozark aquifer that separates low dissolved solids calcium-bicarbonate ground waters to the east from sodium-chloride brines to the west. Two earlier regional studies indicated significant short- and long-term changes in the chemical quality of produced water from several of these wells. It is unclear if the observed changes result from eastward movement of the transition zone due to long-term use or if short-term variability in pumping stress is the more dominant influence. The former implies eastward movement of poorer quality water whereas the later implies local upconing of poorer quality water.
The goal of this proposed project is to assess the influence of pumping on the temporal variability in the quality of water produced in single and multi-aquifer wells within the Ozark aquifer transition zone in southeast Kansas and in southwest Missouri. The project will focus on characterizing (1) the magnitude and timing of the changes in the geochemistry and relative amounts of water provided from each source to the multi-aquifer wells over the period of study relative to pumping stress and (2) the temporal changes in vertical water-quality stratification within the Ozark Plateaus aquifer system within the transition zone relative to pumping stress. The project will also address the temporal aspects of water quality change within the Ozark aquifer transition in the 25 years since previous investigations were reported.
Two sets of nearby wells, each set consisting of an Ozark, Springfield Plateau, and multi-aquifer well and located within the Ozark aquifer transition zone, will be selected for water sampling. Water samples will be collected monthly and analyzed for dissolved major, minor, and selected trace constituents along with records of the amount of water pumped from each well in between samplings. A downhole sonde will be inserted in each multi-aquifer well to monitor changes in specific conductance in the zone where waters from the Springfield Plateau and Ozark aquifers mix within the well. These data will be used to (1) help characterize short-term impacts of pumping on water quality associated with short-term variability (less than one month) in the amount of pumping at each site and (2) provide insight into longer-term water quality changes over the course of the study.
The results will provide timely information to state water-planning agencies, the USGS team of water scientists conducting the Ozark aquifer ground-water flow modeling and water quality assessment project, and water suppliers, particularly in southeast Kansas and southwest Missouri.
Progress/Completion Report, PDF