Highlights of Equus Beds Ground-Water
Recharge Project  

The following link provides a summary of artificial recharge activities as part of the Equus Beds Ground-Water Recharge Demonstration Project. Equus Beds Ground-Water Recharge Demonstration Project 1997-2002.

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Ground-Water Quantity in the Equus Beds Aquifer

• Significant pumping of the Equus Beds Aquifer began in September 1940 resulting in a gradual decrease of the aquifer’s water level. Water-level declines, of up to 40 feet in some areas, occurred in October of 1992 as a result of increased city and agricultural pumpage and the 1988-92 drought.

• Between October 1992 and January 2008, water levels recovered by as much as 20 feet in part of the study area. Decreased city pumpage, because of increasing reliance by Wichita on Cheney Reservoir as a water-supply source, as well as normal to wetter-than-normal rainfall conditions, are the primary reasons for the water-level recoveries. The aquifer’s storage volume recovered by approximately 55 percent during the same period while water levels in many wells recovered to levels similar to those in the late 1970s to early 1980s.

• Since 2007, more than 600 million gallons of water has been recharged through Phase I recharge facilities in the area near Burrton, Kansas.>

• Click here for more information about Changes in Ground-Water Levels and Storage in the Equus Beds Aquifer northwest of Wichita, Kansas.

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Real-Time and Historical Ground-Water-level links for the Equus Beds Aquifer

• At 25S 01W 36BCCD01 VALLEY CENTER WELL
• At 25S 01W 15BBBA01 SEDGWICK WELL
• At 24S 03W 21DDAA05 IW-18C DEEP
• At 24S 02W 16BAAA02 IW-16C DEEP
• At 23S 02W 34ADD 01 TH-04-A1 EB-145-A1
• At 23S 02W 34ADDA02 EB-145-P-D5
• At 22S 02W 30BCBB01 ALTA MILLS

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Surface-Water Quantity

• The source water for the Equus beds artificial recharge project is the Little Arkansas River. During the demonstration phase of the project, according to permit conditions set by the Kansas Department of Agriculture, Division of Water Resources, water could be diverted from the river for recharge under the following conditions:

• At the Halstead Recharge site, from April 1 through September 30, when streamflow at the USGS stream gage Little Arkansas River at Highway 50 near Halstead (07143672) exceeded 42 ft³/s .
• At the Halstead Recharge site, from October 1 through March 31, when streamflow at the USGS stream gage Little Arkansas River at Highway 50 near Halstead (07143672) exceeded 20 ft³/s.
• At the Sedgwick Recharge site, throughout the entire year, when streamflow at the USGS stream gage Little Arkansas River near Sedgwick, KS (07144100) exceeded 40 ft³/s.

• Permit guidelines for Phase I full scale recharge operations established by the Kansas Department of Agriculture, Division of Water Resources, in August 2005, require the following conditions for water to be diverted from the river for recharge:
  • At the Halstead Recharge site, from April 1 through September 30, when streamflow at the USGS stream gage Little Arkansas River at Highway 50 near Halstead (07143672) exceeds 57 ft³/s.
  • At the Halstead Recharge site, from October 1 through March 31, when streamflow at the USGS stream gage Little Arkansas River at Highway 50 near Halstead (07143672) exceeds 20 ft³/s.
  • At the Sedgwick Recharge site there are currently (August 2008) no permit regulations established for full scale recharge operations based on streamflow at the USGS stream gage Little Arkansas River near Sedgwick, KS (07144100).

• The number of days per year when streamflow exceeded minimum diversion requirements is tabulated below. For the site Little Arkansas River at Highway 50 near Halstead, demonstration permit requirements are used from 1995 through 2004 and full scale operation requirements are used from 2005 through September 1, 2008. For the site Little Arkansas River near Sedgwick, demonstration permit requirements are used for all years.

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Water Quality

• Since 1995, water-quality samples have been collected from more than 10 surface-water sites and more than 100 ground-water sites as a part of the Equus Beds Ground-Water Recharge Project. More than 6,000 water-quality samples have been collected and analyzed for more than 400 compounds, including most of the compounds on the U.S. Environmental Protection Agency’s Maximum Contaminant Level (MCL) List for drinking water. The station names and numbers for water-quality monitoring sites are listed in the following link— Equus Beds Ground-Water Recharge Project water-quality monitoring sites.

• The report “Baseline Water Quality and Preliminary Effects of Artificial Recharge on Ground Water, South-Central Kansas, 1995-98” and fact sheet “Effects of Artificial Recharge on Water Quality in the Equus Beds Aquifer, South- Central Kansas, 1995-2000” identify the following constituents to monitor because they frequently (at least 20% of samples collected during baseline sampling) exceeded their respective water-quality standards and criteria:

• Sodium, chloride, total coliform bacteria, and atrazine in surface water
• Nitrite plus nitrate, arsenic, iron, and manganese in ground water

• The following link is a summary table of selected data that exceeded their respective water-quality criteria in surface-water samples collected from February 1995 through December 2007. Data summary for surface-water monitoring sites. The summary includes the water-quality criteria, number of samples collected, minimum, maximum, average, median, percentage of detected compounds, percentage of samples exceeding the water-quality criteria as well as the percentage of replicate samples exceeding the water-quality criteria for each compound.

• Ground-water quality was monitored at 30 wells throughout the study area before recharge activities began to establish a baseline comparison for monitoring the effects of artificial recharge on the Equus Beds aquifer. After 6 years of demonstration artificial recharge activities, the same constituents were identified as requiring monitoring in the ground-water. The following link provides average concentrations of selected data before and after artificial recharge activities. Data summary for effects of artificial recharge.

• Geochemical Effects of Induced Stream-Water and Artificial Recharge on the Equus Beds Aquifer, South Central Kansas, 1995-2004, were defined using simple mixing, solute-transport, and theoretical geochemical models. Simple mixing and solute-transport models indicated that about 75% of the water in the diversion well at Halstead originates from the nearby stream. Geochemical modeling indicated that if fully oxygenated water is injected in the aquifer, chemical precipitation of calcite and iron oxyhydroxide are likely and may reduce the efficiency of the injection wells.

• Data collection from the Areal Index Assessment Network began in November 2001 with two objectives:

• To define general water quality and quantity in the Equus Beds aquifer
• To monitor changes of both water quality and quantity in the Equus Beds aquifer due to artificial recharge

• This network of 76 monitoring wells is located in a 150-square-mile area north of the city of Wichita (study area map). There are 38 locations, positioned every 4 square miles, each with a shallow and a deep monitoring well. The following link provides a summary of selected data in samples collected from November 2001 through December 2007. Data summary for Areal Index Assessment Network.  

• Data collection from 10 Aquifer-Storage and Recovery (ASR) Phase I prototype wells began in December 2002. Data collection from 2 additional ASR prototype wells began in June 2004. Data from these wells will be used in conjunction with data collected during the demonstration phase of the project (1995-2000) along with data that continues to be collected from surface-and ground-water sites to determine the effects of artificial recharge on water quality. The following link provides a summary of selected data in samples collected from December 2002 through December 2007. Data summary for ASR Phase I prototype wells.

• Concentrations and load estimates for select locations of the Little Arkansas River indicate that the sources of the loads of chloride and fecal coliform bacteria are upstream of Highway 50. The concentrations and load estimates also indicate that atrazine loads are distributed throughout the basin. For further information refer to “Regression Analysis and Real-Time Water-Quality Monitoring to Estimate Constituent Concentrations, Loads, and Yields in the Little Arkansas River, South-Central Kansas, 1995-99.” In addition, hourly estimates of concentrations and loads for these sites from 1999 to today are available at http://ks.water.usgs.gov/rtqw/

• The Equus Beds Aquifer Storage and Recovery (ASR) Project Phase I began in 2006 “to inject ground water into the Equus Beds Aquifer for the purpose of storage and later recovery of the ground water and to form a hydraulic barrier to a known brine plume” (Kansas Underground Injection Control Area Permit Class V Injection Well, Kansas Permit No. KS-05-079-001). The project diverts water from the Little Arkansas River through bank storage (diversion) wells, completed adjacent to the stream, when flow in the Little Arkansas River exceeds base flow (base flows can be found in the “Surface-Water Quantity” section above). The diverted water is artificially recharged into the Equus Beds aquifer through injection wells and recharge basins. The following link provides more information on the Equus Beds Aquifer Storage and Recovery (ASR) Project Phase I. Equus Beds Aquifer Storage and Recovery Project Phase 1.

• Click on the following links for complete statistical information on all sites sampled from February 1995- December 2007 as part of the Equus Beds Ground-Water Recharge Project:
  • Abbreviations and definitions associated with the statistical summaries
  • Little Arkansas River at Highway 50 near Halstead, KS
  • Little Arkansas River near Sedgwick, KS
  • Diversion well site near Halstead, KS
  • Halstead recharge site near Halstead, KS
  • Monitoring wells near Halstead recharge site
  • Sedgwick recharge site near Sedgwick, KS
  • Monitoring wells near Sedgwick recharge site
  • Background wells
  • Areal Index Assessment Network
  • Aquifer-Storage and Recovery (ASR) prototype wells
  • Local well field at Wichita, KS
  • Miscellaneous surface-water sites

• Click on the following links for complete data tables on all sites sampled from August 2006 - March 2008 as part of the Equus Beds Aquifer Storage and Recovery (ASR) Project Phase I:

• Abbreviations and units of measure used in data tables
• Table 1: Inorganics, nutrients & bacteria  
• Table 2: Trace elements
• Table 3: Pesticides
• Table 4: Volatile organic compounds
• Table 5: Radionuclides
• Table 6 & 7: Acid & Base/Neutral compounds

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