Equus Beds Aquifer Storage and Recovery (ASR) Project Active
The water supply for the city of Wichita, south-central Kansas, currently comes from the Equus Beds aquifer and Cheney Reservoir. Because these sources are not expected to meet projected city water needs into the 21st century (Warren and others, 1995), artificial recharge of the Equus Beds aquifer was investigated as one alternative to meet future water-supply demands. An additional potential benefit of artificial recharge includes preventing degradation of the water quality of the aquifer by saltwater plumes from the Arkansas River to the southwest and the Burrton oil field to the northwest (Ziegler and others, 1999). Phase I of the full-scale artificial recharge project began in 2007 and continued through 2012. Phase II became operational in April 2013 and has a design capacity of 30 Mgal/day.
Real-time Data:
Surface-water and groundwater sites:
National Real-Time Water Quality
National Water Dashboard
The Equus Beds ASR Project is a recent part of an 80-year cooperative water science effort with the city of Wichita, Kansas that began in the 1920s as the city began its water-supply development (Stone, 2017). Current (2023) water-quality monitoring efforts provides data to characterize real-time and changing water-quality measurements and allows the city of Wichita to make informed municipal water-supply decisions.
The city of Wichita, Kansas, uses the Equus Beds aquifer as a primary municipal water-supply source. Equus Beds aquifer water levels have decreased substantially (Hansen and others, 2014; Whisnant and others, 2015; Klager, 2016) because historically, irrigator, industrial, and municipal pumpage volumes exceeded the natural aquifer recharge rate. The Wichita well field is susceptible to saltwater (including chloride) contamination from the Arkansas River and intrusion from existing upgradient plumes near Burrton, Kansas, caused by oil field evaporation pits remaining from the 1930s (Klager and others, 2014). The Equus Beds ASR project was created by the city of Wichita to help meet future water demands.
The Equus Beds ASR project currently (2023) consists of two coexisting phases:
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Phase I began in 2007 and has the capacity to capture 10 million gallons per day (Mgal/d) of Little Arkansas River water and indirect streambank-diversion well water for recharge activity with water injection in four wells and two recharge basins. Directly diverted stream water is treated using membrane filtration and advanced oxidation to reduce sediment and remove organic material before being recharged through the two recharge basins; streambank-diversion well pumped water is not treated further before recharge through the injection wells or basins (Garinger and others, 2011).
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Phase II began in 2013 and includes a 30-Mgal/d surface-water treatment facility, a 60-Mgal/d river intake facility equipped to divert 30 Mgal/d and treat 15 Mgal/d, eight recharge-injection wells, and a recharge basin. The facility capacity of 30 Mgal/d requires a streamflow of about 100 cubic feet per second (ft3/s) or greater at the Little Arkansas River near Sedgwick, Kans., streamgage (USGS station 07144100; fig. 1) to operate. Water is directly diverted from the Little Arkansas River at the intake structure when streamflow exceeds about 100 ft3/s at this site. The city of Wichita has a National Pollutant Discharge Elimination System (NPDES) permit (Kansas Permit number I-LA24-PO01; Federal Permit number KS0099694) to discharge waste from the ASR phase II surface-water treatment facility to the Little Arkansas River.
Figure 1. Location of the Equus Beds ASR project study area near Wichita, south-central Kansas.
Equus Beds ASR project study highlights:
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The amount of aquifer water volume has recovered since the historic 1993 low because of less pumping, more natural recharge, and ASR (Klager, 2016).
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The chloride plume near Burrton, Kans. (figs 1, 2, and 3), moves about 0.6 foot per day eastward toward the Wichita well field regardless of pumping (fig. 2; Klager and others, 2014).
Figure 2. Animation showing simulated chloride transport in the deep layer of the Equus Beds aquifer under existing pumping conditions from 1990 through 2008 (Klager and others, 2014).
Figure 3. Equus Beds ASR Project study area map showing shallow aquifer water-level changes from predevelopment to 1993 and chloride plume in deep wells that exceed U.S. Environmental Protection Agency drinking water criterion (>250 milligrams per liter) during 2006–12 moving eastward.
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Water-quality constituents of concern collected during 1995 through 2012 did not increase substantially during and concurrent with Phase I activity and were likely more affected by climatological and natural processes than artificial recharge (Tappa and others, 2015).
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A Hydrobiological Monitoring Project (HBMP) study using data collected during 2011–2014 showed that Phase II recharge activities did not result in substantial changes in Little Arkansas River or Equus Beds aquifer water quality; most Little Arkansas River water chemistry and biology (macroinvertebrates and fish) changes were largely attributable to hydrology (Stone and others, 2016).
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Little Arkansas River water-quality constituent concentrations collected during 2001 through 2016 did not increase in comparison to sampling that preceded (1995 through 2012; Tappa and others, 2015) the study. Constituents of concern in the Equus Beds aquifer exceeded their respective Federal criteria throughout the study period and included chloride, sulfate, nitrate plus nitrite, Escherichia coli bacteria, total coliforms, and dissolved iron and arsenic species. (table 1; Stone and others, 2019).
Water-quality constituent or mineral phase | Federal MCL or SMCL or MCLG |
USGS pcode | n | Min | Max | Mean | Median | Percent exceeding MCL or SMCL |
---|---|---|---|---|---|---|---|---|
Surface Water | ||||||||
Chloride, in mg/L | 250mg/L | 00940 | 387 | <5 | 530 | 84.3 | 60.0 | <1 |
Sulfate, in mg/L | 250mg/L | 00945 | 387 | <5 | 170 | 39 | 38 | 0 |
Nitrate plus nitrite as nitrogen, in mg/L | 10mg/L | 00631 | 389 | <0.02 | 11.7 | 1.11 | 0.85 | <1 |
Total coliform bacteria, in cfu/100 mL | 0 cfu/100 mL | 31504 | 181 | 30 | 360,000 | 14,351 | 2,440 | 100 |
Iron, in µg/L | 300 µg/L | 01046 | 370 | <4 | 620 | 81 | 50 | 7 |
Manganese, in µg/L | 50 µg/L | 01056 | 291 | <1 | 826 | 129 | 42 | 48 |
Arsenic, in µg/L | 10 µg/L | 01000 | 376 | <1 | 16.2 | 5.77 | 5.00 | 12 |
Atrazine, in µg/L | 3.0 µg/L | 39632 | 358 | <0.025 | 48.0 | 4.73 | 1.61 | 39 |
Shallow index wells | ||||||||
Chloride, in mg/L | 250mg/L | 00940 | 705 | <5 | 773 | 67.0 | 36 | 5 |
Sulfate, in mg/L | 250mg/L | 00945 | 699 | <5 | 770 | 152 | 100 | 18 |
Nitrate plus nitrite as nitrogen, in mg/L | 10mg/L | 00631 | 705 | <0.02 | 42.6 | 3.79 | 0.70 | 15 |
Total coliform bacteria, in cfu/100 mL | 0 cfu/100 mL | 31504 | 441 | <1 | 368 | 7 | 1 | 3 |
Iron, in µg/L | 300 µg/L | 01046 | 695 | <5 | 40,700 | 2,437 | 107 | 38 |
Manganese, in µg/L | 50 µg/L | 01056 | 692 | <1 | 1,660 | 279 | 90 | 55 |
Arsenic, in µg/L | 10 µg/L | 01000 | 703 | <1.0 | 55.0 | 3.83 | 1.50 | 12 |
Atrazine, in µg/L | 3.0 µg/L | 39632 | 246 | <0.006 | 2.280 | 0.062 | 0.009 | 0 |
Calcite, SI | - | - | 679 | -3.60 | 0.27 | -0.71 | -0.51 | - |
Iron (III) hydroxide, SI | - | - | 679 | -4.75 | 4.34 | 0.72 | 0.60 | - |
Iron hydroxide, SI | - | - | 679 | -13.69 | 6.88 | -2.52 | -1.92 | - |
Deep index wells | ||||||||
Chloride, in mg/L | 250mg/L | 00940 | 708 | <5 | 1,460 | 110.0 | 65 | 7 |
Sulfate, in mg/L | 250mg/L | 00945 | 705 | <5 | 720 | 1.11 | 69 | 13 |
Nitrate plus nitrite as nitrogen, in mg/L | 10mg/L | 00631 | 713 | <0.02 | 11.3 | 0.48 | 0.01 | <1 |
Total coliform bacteria, in cfu/100 mL | 0 cfu/100 mL | 31504 | 442 | <1 | 84 | - | - | 3 |
Iron, in µg/L | 300 µg/L | 01046 | 702 | <5 | 17,900 | 1,441 | 150 | 46 |
Manganese, in µg/L | 50 µg/L | 01056 | 707 | <1 | 1,640 | 440 | 310 | 92 |
Arsenic, in µg/L | 10 µg/L | 01000 | 705 | <1.0 | 23.9 | 7.43 | 6.00 | 34 |
Atrazine, in µg/L | 3.0 µg/L | 39632 | 183 | <0.007 | 0.090 | 0.009 | 0.004 | 0 |
Calcite, SI | - | - | 655 | -1.33 | 0.84 | -0.21 | -0.16 | - |
Iron (III) hydroxide, SI | - | - | 655 | -4.69 | 4.63 | 0.71 | 0.63 | - |
Iron hydroxide, SI | - | - | 655 | -13.49 | 7.89 | -1.35 | -0.90 | - |
Table 1. Little Arkansas River surface-water and Equus Beds index well groundwater water-quality summary statistics during 2001–16.
Figure 4. Average A, nitrate plus nitrite and B, dissolved arsenic concentrations in the shallow parts (depths below land surface equal to or less than 80 feet) of the Equus Beds aquifer 2001–16.
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Little Arkansas River real-time computations of water-quality constituents for three Little Arkansas sites are available at the USGS National Real-Time Water Quality website (https:// nrtwq.usgs.gov) and include dissolved solids, primary ions (including bromide), nutrients, sediment, dissolved arsenic, and pesticides (including atrazine; Stone and Klager, 2022; Stone and Klager, 2023).
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Little Arkansas River long-term (1995–2021) trend analyses showed that, generally, flow-normalized bromide, nitrate, and total phosphorus concentrations decreased; total organic carbon increased; and sediment concentrations neither increased or decreased. About one-quarter to one-half of the river loads, including nutrients and sediment, were transported during 1 percent of the time during the study (Stone and Klager, 2023).
Below are publications associated with this project.
Water resources of Sedgwick County, Kansas
Ground-water flow and solute transport in the Equus beds area, south-central Kansas, 1940-79
Natural ground-water-recharge data from three selected sites in Harvey County, south-central Kansas
Below are partners associated with this project.
- Overview
The water supply for the city of Wichita, south-central Kansas, currently comes from the Equus Beds aquifer and Cheney Reservoir. Because these sources are not expected to meet projected city water needs into the 21st century (Warren and others, 1995), artificial recharge of the Equus Beds aquifer was investigated as one alternative to meet future water-supply demands. An additional potential benefit of artificial recharge includes preventing degradation of the water quality of the aquifer by saltwater plumes from the Arkansas River to the southwest and the Burrton oil field to the northwest (Ziegler and others, 1999). Phase I of the full-scale artificial recharge project began in 2007 and continued through 2012. Phase II became operational in April 2013 and has a design capacity of 30 Mgal/day.
Real-time Data:Surface-water and groundwater sites:
National Real-Time Water QualityNational Water DashboardThe Equus Beds ASR Project is a recent part of an 80-year cooperative water science effort with the city of Wichita, Kansas that began in the 1920s as the city began its water-supply development (Stone, 2017). Current (2023) water-quality monitoring efforts provides data to characterize real-time and changing water-quality measurements and allows the city of Wichita to make informed municipal water-supply decisions.
The city of Wichita, Kansas, uses the Equus Beds aquifer as a primary municipal water-supply source. Equus Beds aquifer water levels have decreased substantially (Hansen and others, 2014; Whisnant and others, 2015; Klager, 2016) because historically, irrigator, industrial, and municipal pumpage volumes exceeded the natural aquifer recharge rate. The Wichita well field is susceptible to saltwater (including chloride) contamination from the Arkansas River and intrusion from existing upgradient plumes near Burrton, Kansas, caused by oil field evaporation pits remaining from the 1930s (Klager and others, 2014). The Equus Beds ASR project was created by the city of Wichita to help meet future water demands.
The Equus Beds ASR project currently (2023) consists of two coexisting phases:
-
Phase I began in 2007 and has the capacity to capture 10 million gallons per day (Mgal/d) of Little Arkansas River water and indirect streambank-diversion well water for recharge activity with water injection in four wells and two recharge basins. Directly diverted stream water is treated using membrane filtration and advanced oxidation to reduce sediment and remove organic material before being recharged through the two recharge basins; streambank-diversion well pumped water is not treated further before recharge through the injection wells or basins (Garinger and others, 2011).
-
Phase II began in 2013 and includes a 30-Mgal/d surface-water treatment facility, a 60-Mgal/d river intake facility equipped to divert 30 Mgal/d and treat 15 Mgal/d, eight recharge-injection wells, and a recharge basin. The facility capacity of 30 Mgal/d requires a streamflow of about 100 cubic feet per second (ft3/s) or greater at the Little Arkansas River near Sedgwick, Kans., streamgage (USGS station 07144100; fig. 1) to operate. Water is directly diverted from the Little Arkansas River at the intake structure when streamflow exceeds about 100 ft3/s at this site. The city of Wichita has a National Pollutant Discharge Elimination System (NPDES) permit (Kansas Permit number I-LA24-PO01; Federal Permit number KS0099694) to discharge waste from the ASR phase II surface-water treatment facility to the Little Arkansas River.
Figure 1. Location of the Equus Beds ASR project study area near Wichita, south-central Kansas.
Equus Beds ASR project study highlights:
-
The amount of aquifer water volume has recovered since the historic 1993 low because of less pumping, more natural recharge, and ASR (Klager, 2016).
-
The chloride plume near Burrton, Kans. (figs 1, 2, and 3), moves about 0.6 foot per day eastward toward the Wichita well field regardless of pumping (fig. 2; Klager and others, 2014).
Figure 2. Animation showing simulated chloride transport in the deep layer of the Equus Beds aquifer under existing pumping conditions from 1990 through 2008 (Klager and others, 2014).
Figure 3. Equus Beds ASR Project study area map showing shallow aquifer water-level changes from predevelopment to 1993 and chloride plume in deep wells that exceed U.S. Environmental Protection Agency drinking water criterion (>250 milligrams per liter) during 2006–12 moving eastward.
-
Water-quality constituents of concern collected during 1995 through 2012 did not increase substantially during and concurrent with Phase I activity and were likely more affected by climatological and natural processes than artificial recharge (Tappa and others, 2015).
-
A Hydrobiological Monitoring Project (HBMP) study using data collected during 2011–2014 showed that Phase II recharge activities did not result in substantial changes in Little Arkansas River or Equus Beds aquifer water quality; most Little Arkansas River water chemistry and biology (macroinvertebrates and fish) changes were largely attributable to hydrology (Stone and others, 2016).
-
Little Arkansas River water-quality constituent concentrations collected during 2001 through 2016 did not increase in comparison to sampling that preceded (1995 through 2012; Tappa and others, 2015) the study. Constituents of concern in the Equus Beds aquifer exceeded their respective Federal criteria throughout the study period and included chloride, sulfate, nitrate plus nitrite, Escherichia coli bacteria, total coliforms, and dissolved iron and arsenic species. (table 1; Stone and others, 2019).
Water-quality constituent or mineral phase Federal MCL or
SMCL or MCLGUSGS pcode n Min Max Mean Median Percent exceeding MCL or SMCL Surface Water Chloride, in mg/L 250mg/L 00940 387 <5 530 84.3 60.0 <1 Sulfate, in mg/L 250mg/L 00945 387 <5 170 39 38 0 Nitrate plus nitrite as nitrogen, in mg/L 10mg/L 00631 389 <0.02 11.7 1.11 0.85 <1 Total coliform bacteria, in cfu/100 mL 0 cfu/100 mL 31504 181 30 360,000 14,351 2,440 100 Iron, in µg/L 300 µg/L 01046 370 <4 620 81 50 7 Manganese, in µg/L 50 µg/L 01056 291 <1 826 129 42 48 Arsenic, in µg/L 10 µg/L 01000 376 <1 16.2 5.77 5.00 12 Atrazine, in µg/L 3.0 µg/L 39632 358 <0.025 48.0 4.73 1.61 39 Shallow index wells Chloride, in mg/L 250mg/L 00940 705 <5 773 67.0 36 5 Sulfate, in mg/L 250mg/L 00945 699 <5 770 152 100 18 Nitrate plus nitrite as nitrogen, in mg/L 10mg/L 00631 705 <0.02 42.6 3.79 0.70 15 Total coliform bacteria, in cfu/100 mL 0 cfu/100 mL 31504 441 <1 368 7 1 3 Iron, in µg/L 300 µg/L 01046 695 <5 40,700 2,437 107 38 Manganese, in µg/L 50 µg/L 01056 692 <1 1,660 279 90 55 Arsenic, in µg/L 10 µg/L 01000 703 <1.0 55.0 3.83 1.50 12 Atrazine, in µg/L 3.0 µg/L 39632 246 <0.006 2.280 0.062 0.009 0 Calcite, SI - - 679 -3.60 0.27 -0.71 -0.51 - Iron (III) hydroxide, SI - - 679 -4.75 4.34 0.72 0.60 - Iron hydroxide, SI - - 679 -13.69 6.88 -2.52 -1.92 - Deep index wells Chloride, in mg/L 250mg/L 00940 708 <5 1,460 110.0 65 7 Sulfate, in mg/L 250mg/L 00945 705 <5 720 1.11 69 13 Nitrate plus nitrite as nitrogen, in mg/L 10mg/L 00631 713 <0.02 11.3 0.48 0.01 <1 Total coliform bacteria, in cfu/100 mL 0 cfu/100 mL 31504 442 <1 84 - - 3 Iron, in µg/L 300 µg/L 01046 702 <5 17,900 1,441 150 46 Manganese, in µg/L 50 µg/L 01056 707 <1 1,640 440 310 92 Arsenic, in µg/L 10 µg/L 01000 705 <1.0 23.9 7.43 6.00 34 Atrazine, in µg/L 3.0 µg/L 39632 183 <0.007 0.090 0.009 0.004 0 Calcite, SI - - 655 -1.33 0.84 -0.21 -0.16 - Iron (III) hydroxide, SI - - 655 -4.69 4.63 0.71 0.63 - Iron hydroxide, SI - - 655 -13.49 7.89 -1.35 -0.90 - Table 1. Little Arkansas River surface-water and Equus Beds index well groundwater water-quality summary statistics during 2001–16.
Figure 4. Average A, nitrate plus nitrite and B, dissolved arsenic concentrations in the shallow parts (depths below land surface equal to or less than 80 feet) of the Equus Beds aquifer 2001–16.
-
Little Arkansas River real-time computations of water-quality constituents for three Little Arkansas sites are available at the USGS National Real-Time Water Quality website (https:// nrtwq.usgs.gov) and include dissolved solids, primary ions (including bromide), nutrients, sediment, dissolved arsenic, and pesticides (including atrazine; Stone and Klager, 2022; Stone and Klager, 2023).
-
Little Arkansas River long-term (1995–2021) trend analyses showed that, generally, flow-normalized bromide, nitrate, and total phosphorus concentrations decreased; total organic carbon increased; and sediment concentrations neither increased or decreased. About one-quarter to one-half of the river loads, including nutrients and sediment, were transported during 1 percent of the time during the study (Stone and Klager, 2023).
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- Publications
Below are publications associated with this project.
Filter Total Items: 39Water resources of Sedgwick County, Kansas
Hydrologic data from streams, impoundments, and wells are interpreted to: (1) document water resources characteristics; (2) describe causes and extent of changes in water resources characteristics; and (3) evaluate water resources as sources of supply. During 1985, about 134,200 acre-ft of water (84% groundwater) were used for public (42%), irrigation, (40%), industrial (14%), and domestic (4%) suAuthorsH.E. BevansGround-water flow and solute transport in the Equus beds area, south-central Kansas, 1940-79
Water levels have declined about 30 ft from 1940 to 1980 in part of the Equus beds aquifer in south-central Kansas where the city of Wichita operates a well field. A three-dimensional, finite-difference, groundwater flow model was developed to: (1) Reproduce hydrologic conditions in the flow system between the Equus beds aquifer and the underlying Wellington aquifer from 1940 to 1980, and (2) simuAuthorsJ. M. Spinazola, James B. Gillespie, R. J. HartNatural ground-water-recharge data from three selected sites in Harvey County, south-central Kansas
The cities of Wichita, Newton, and several smaller towns pump large quantities of water from the 'Equus Beds' aquifer in south-central Kansas. The aquifer also supplies large quantities of water for irrigation at a steadily increasing rate. The Harvey County Planning and Zoning Commission entered into a cooperative agreement with the U.S. Geological Survey to collect information on natural rechargAuthorsC. A. Perry - Partners
Below are partners associated with this project.