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.
Phase I of the full-scale artificial recharge project began in 2007 and continued through 2012. For Phase I, the water pumped directly from the Little Arkansas River was treated to reduce sediment and remove atrazine before being recharged to the aquifer through recharge basins; water pumped from wells in the riverbank did not receive additional treatment before being recharged to the aquifer through recharge basins or wells (Debra Ary, city of Wichita, written commun., 2012). Phase II recharge facilities withdraw water from the Little Arkansas River and treat the water using ultrafiltration membranes and advanced oxidation techniques. The treated water can then be recharged into spreading basins or recharge wells throughout the area and stored in the aquifer for future use. Phase I has a design capacity of 10 Mgal/day. Phase II became operational in April 2013 and has a design capacity of 30 Mgal/day. Total construction costs for Phase I and II were about $247 million.
Map of Operations for Equus Beds Groundwater Recharge Project
City of Wichita Aquifer Storage and Recovery Program:
http://www.wichita.gov/
http://www.wichita.gov/Government/Departments/PWU/Pages/WaterQuality.aspx
Water Quality
Expected effects of artificial recharge
- Will increase water levels and storage in the aquifer
- Will slow down southeast movement of chloride near Burrton and along the Arkansas River
- As water levels increase, concentrations of some metals may temporarily increase until reaches geochemical equilibria
- Recharge of oxygenated water will decrease concentrations of metals—as long as it remains oxygenated
Water-quality changes associated with Phase I & Phase II recharge
- Kansas Underground Injection Control Area Permit Class V Aquifier Storage and Recovery, Kansas Permit No. KS-05-079-004
- Water-quality Data Compilation for 2010-2016
What controls the water quality?
- Chloride — proximity to Burrton and Arkansas River and possible dilution by recharge water or increased hydraulic head slowing the movement of the chloride plume
- Arsenic, iron, and manganese — presence in aquifer materials, distribution of clays, chemically reducing conditions, and areas of larger water level declines
- If oxygenated water is recharged into a reducing aquifer, concentrations of dissolved arsenic, iron and manganese will decrease because these constituents will precipitate from solution
- Nitrate, atrazine, and bacteria in surface water, — controlled by runoff and agricultural land use
Chlorides
Chloride concentrations exceeded the SDWR of 250 mg/l in less than 8% of the shallow and deep parts of the aquifer. Crop yields decrease if concentrations >350 mg/L (Bauder and others, 2007).
Concentrations larger than 500 mg/L were found near Burrton, where previous oilfield brine disposal occurred. These brines have moved about 3 miles in the past 45 years. Also, large concentrations of chloride from the Arkansas River are moving into the aquifer because of ground water declines caused by agricultural and city pumping.
Chloride is moving……..slowly….. Phase 1 artificial recharge may have helped stabilize chloride concentrations from 2004 to 2010 and likely again in 2013. Concentrations increased in 2011 and 2012 due to curtailed recharge as a result of drought-related low flows in the Little Arkansas River, but corresponding with Phase I & II recharge activities: 2013 chloride concentrations are again showing signs of stability while ASR is operated.
Arsenic
Why is Arsenic an issue in the Equus Beds Aquifer?
- There is an EPA Maximum contaminant level (MCL) of 10 micrograms per liter (ppb). Before 2006, the criterion was 50 ppb. Annual samples are required. If the criterion is exceed, then quarterly are required. The MCL is the annual average of the collected samples.
- Background concentrations (before recharge) for arsenic exceeded 10 ppb in several wells and in the Little Arkansas River.
- Arsenic is naturally present in the aquifer sediments.
- Arsenic is controlled by the geochemistry of the aquifer material and the oxygen conditions in the aquifer.
http://water.usgs.gov/nawqa/trace/pubs/geo_v46n11/fig3.html
BASELINE (1995-2013) Arsenic concentrations in shallow groundwater (well less than 80 feet deep)
- Arsenic concentrations exceed 10 ppb in 12% of samples
- Arsenic concentrations exceeding 10 ppb are associated with low (no) oxygen, clays, and areas of water-level declines
BASELINE (1995-2012) Arsenic concentrations in deep groundwater
- Concentrations exceed 10 ppb in 35 % of deep groundwater
- Concentrations are controlled by low (no) oxygen, more clay, and possibly thicker aquifer
Computed dissolved arsenic concentration in the Little Arkansas River at Highway 50 near Halstead, KS
- When streamflow exceeds 57 cfs, arsenic doesn’t exceed 10 ppb, therefore, arsenic in treated surface water is not a problem for artificial recharge.
- From 1999-2012, Arsenic exceeded 10 ppb about 15% of time. However, due to low flows in 2013, computed arsenic concentrations exceeded 10 ppb about 75% of the time.
Arsenic variability is much greater than chloride variability.
General Geochemical controls for Arsenic
- Minerals important for recharge and geochemistry
- Calcite (calcium carbonate)
- Pyrite (iron sulfide) (can contain arsenic)- Sources
- Iron hydroxides (both source and sink)
- Controls
- Clays
- Oxygen (oxidation-reduction potential or Eh)
- Concentrations
Natural geochemical process of arsenic concentrations in an aquifer
- Controlled by:
- Sources–clay-rich areas have more pyrite (and sorbed arsenic)
- Oxygen(or lack of oxygen); more oxygen = less dissolved arsenic
- Infiltrating water quality and receiving aquifer quality
- What does this mean in the aquifer?
- Dewatered areas oxygenate and destabilize arsenic-containing pyrites
- Arsenic and iron are dissolved or leached
- As a result of increasing oxygen concentrations from either dewatering or the recharge of oxygenated water, amorphous iron oxides (hydroxides, oxyhydroxides) may form.
- Dissolved arsenic species can be scavenged by or sorb to the surfaces of precipitated iron oxide species, and are, therefore, removed from groundwater
- In summary, a new equilibrium is reached in the aquifer that is primarily controlled by oxygen availability
Below are publications associated with this project.
Water-quality and geochemical variability in the Little Arkansas River and Equus Beds aquifer, south-central Kansas, 2001–16
Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2016
Relations between continuous real-time physical properties and discrete water-quality constituents in the Little Arkansas River, south-central Kansas, 1998-2014
Effects of aquifer storage and recovery activities on water quality in the Little Arkansas River and Equus Beds Aquifer, south-central Kansas, 2011–14
Groundwater-level and storage-volume changes in the Equus Beds aquifer near Wichita, Kansas, predevelopment through January 2015
Water quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012
Water quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012
Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, 2012 to 2014
Preliminary simulation of chloride transport in the Equus Beds aquifer and simulated effects of well pumping and artificial recharge on groundwater flow and chloride transport near the city of Wichita, Kansas, 1990 through 2008
Revised shallow and deep water-level and storage-volume changes in the Equus Beds Aquifer near Wichita, Kansas, predevelopment to 1993
Irrigation trends in Kansas, 1991-2011
Simulation of groundwater flow, effects of artificial recharge, and storage volume changes in the Equus Beds aquifer near the city of Wichita, Kansas well field, 1935–2008
Below are data or web applications associated with this project.
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.
Phase I of the full-scale artificial recharge project began in 2007 and continued through 2012. For Phase I, the water pumped directly from the Little Arkansas River was treated to reduce sediment and remove atrazine before being recharged to the aquifer through recharge basins; water pumped from wells in the riverbank did not receive additional treatment before being recharged to the aquifer through recharge basins or wells (Debra Ary, city of Wichita, written commun., 2012). Phase II recharge facilities withdraw water from the Little Arkansas River and treat the water using ultrafiltration membranes and advanced oxidation techniques. The treated water can then be recharged into spreading basins or recharge wells throughout the area and stored in the aquifer for future use. Phase I has a design capacity of 10 Mgal/day. Phase II became operational in April 2013 and has a design capacity of 30 Mgal/day. Total construction costs for Phase I and II were about $247 million.
Map of Operations for Equus Beds Groundwater Recharge Project
City of Wichita Aquifer Storage and Recovery Program:
http://www.wichita.gov/
http://www.wichita.gov/Government/Departments/PWU/Pages/WaterQuality.aspxWater Quality
Expected effects of artificial recharge
- Will increase water levels and storage in the aquifer
- Will slow down southeast movement of chloride near Burrton and along the Arkansas River
- As water levels increase, concentrations of some metals may temporarily increase until reaches geochemical equilibria
- Recharge of oxygenated water will decrease concentrations of metals—as long as it remains oxygenated
Water-quality changes associated with Phase I & Phase II recharge
- Kansas Underground Injection Control Area Permit Class V Aquifier Storage and Recovery, Kansas Permit No. KS-05-079-004
- Water-quality Data Compilation for 2010-2016
What controls the water quality?
- Chloride — proximity to Burrton and Arkansas River and possible dilution by recharge water or increased hydraulic head slowing the movement of the chloride plume
- Arsenic, iron, and manganese — presence in aquifer materials, distribution of clays, chemically reducing conditions, and areas of larger water level declines
- If oxygenated water is recharged into a reducing aquifer, concentrations of dissolved arsenic, iron and manganese will decrease because these constituents will precipitate from solution
- Nitrate, atrazine, and bacteria in surface water, — controlled by runoff and agricultural land use
Chlorides
Chloride concentrations exceeded the SDWR of 250 mg/l in less than 8% of the shallow and deep parts of the aquifer. Crop yields decrease if concentrations >350 mg/L (Bauder and others, 2007).
Concentrations larger than 500 mg/L were found near Burrton, where previous oilfield brine disposal occurred. These brines have moved about 3 miles in the past 45 years. Also, large concentrations of chloride from the Arkansas River are moving into the aquifer because of ground water declines caused by agricultural and city pumping.
Chloride is moving……..slowly….. Phase 1 artificial recharge may have helped stabilize chloride concentrations from 2004 to 2010 and likely again in 2013. Concentrations increased in 2011 and 2012 due to curtailed recharge as a result of drought-related low flows in the Little Arkansas River, but corresponding with Phase I & II recharge activities: 2013 chloride concentrations are again showing signs of stability while ASR is operated.
Arsenic
Why is Arsenic an issue in the Equus Beds Aquifer?
- There is an EPA Maximum contaminant level (MCL) of 10 micrograms per liter (ppb). Before 2006, the criterion was 50 ppb. Annual samples are required. If the criterion is exceed, then quarterly are required. The MCL is the annual average of the collected samples.
- Background concentrations (before recharge) for arsenic exceeded 10 ppb in several wells and in the Little Arkansas River.
- Arsenic is naturally present in the aquifer sediments.
- Arsenic is controlled by the geochemistry of the aquifer material and the oxygen conditions in the aquifer.
http://water.usgs.gov/nawqa/trace/pubs/geo_v46n11/fig3.html
BASELINE (1995-2013) Arsenic concentrations in shallow groundwater (well less than 80 feet deep)
- Arsenic concentrations exceed 10 ppb in 12% of samples
- Arsenic concentrations exceeding 10 ppb are associated with low (no) oxygen, clays, and areas of water-level declines
BASELINE (1995-2012) Arsenic concentrations in deep groundwater
- Concentrations exceed 10 ppb in 35 % of deep groundwater
- Concentrations are controlled by low (no) oxygen, more clay, and possibly thicker aquifer
Computed dissolved arsenic concentration in the Little Arkansas River at Highway 50 near Halstead, KS
- When streamflow exceeds 57 cfs, arsenic doesn’t exceed 10 ppb, therefore, arsenic in treated surface water is not a problem for artificial recharge.
- From 1999-2012, Arsenic exceeded 10 ppb about 15% of time. However, due to low flows in 2013, computed arsenic concentrations exceeded 10 ppb about 75% of the time.
Arsenic variability is much greater than chloride variability.
General Geochemical controls for Arsenic
- Minerals important for recharge and geochemistry
- Calcite (calcium carbonate)
- Pyrite (iron sulfide) (can contain arsenic)- Sources
- Iron hydroxides (both source and sink)
- Controls
- Clays
- Oxygen (oxidation-reduction potential or Eh)
- Concentrations
Natural geochemical process of arsenic concentrations in an aquifer
- Controlled by:
- Sources–clay-rich areas have more pyrite (and sorbed arsenic)
- Oxygen(or lack of oxygen); more oxygen = less dissolved arsenic
- Infiltrating water quality and receiving aquifer quality
- What does this mean in the aquifer?
- Dewatered areas oxygenate and destabilize arsenic-containing pyrites
- Arsenic and iron are dissolved or leached
- As a result of increasing oxygen concentrations from either dewatering or the recharge of oxygenated water, amorphous iron oxides (hydroxides, oxyhydroxides) may form.
- Dissolved arsenic species can be scavenged by or sorb to the surfaces of precipitated iron oxide species, and are, therefore, removed from groundwater
- In summary, a new equilibrium is reached in the aquifer that is primarily controlled by oxygen availability
- Multimedia
- Publications
Below are publications associated with this project.
Filter Total Items: 37Water-quality and geochemical variability in the Little Arkansas River and Equus Beds aquifer, south-central Kansas, 2001–16
This fact sheet describes water quality and geochemistry of the Little Arkansas River and Equus Beds aquifer during 2001 through 2016 as part of the City of Wichita’s Equus Beds aquifer storage and recovery project in south-central Kansas. The Equus Beds aquifer storage and recovery project was developed to help meet future water demand by pumping water out of the Little Arkansas River (during aboStatus of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2016
The Equus Beds aquifer in south-central Kansas, which is part of the High Plains aquifer, serves as a source of water for municipal and agricultural users in the area. The city of Wichita has used the Equus Beds aquifer as one of its primary water sources since the 1940s. The aquifer in and around Wichita’s well field reached historically low water levels in 1993, prompting the city to adopt new wRelations between continuous real-time physical properties and discrete water-quality constituents in the Little Arkansas River, south-central Kansas, 1998-2014
Water from the Little Arkansas River is used as source water for artificial recharge of the Equus Beds aquifer, one of the primary water-supply sources for the city of Wichita, Kansas. The U.S. Geological Survey has operated two continuous real-time water-quality monitoring stations since 1995 on the Little Arkansas River in Kansas. Regression models were developed to establish relations between dEffects of aquifer storage and recovery activities on water quality in the Little Arkansas River and Equus Beds Aquifer, south-central Kansas, 2011–14
The Equus Beds aquifer in south-central Kansas is aprimary water source for the city of Wichita. The Equus Beds aquifer storage and recovery (ASR) project was developed to help the city of Wichita meet increasing current (2016) and future water demands. The Equus Beds ASR project pumps water out of the Little Arkansas River during above-base flow conditions, treats it using drinking-water qualityGroundwater-level and storage-volume changes in the Equus Beds aquifer near Wichita, Kansas, predevelopment through January 2015
Development of the Wichita well field began in the 1940s in the Equus Beds aquifer to provide the city of Wichita, Kansas, a new water-supply source. After development of the Wichita well field began, groundwater levels began to decline. Extensive development of irrigation wells that began in the 1970s also contributed to substantial groundwater-level declines. Groundwater-level declines likely enWater quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012
The city of Wichita artificially recharged about 1 billion gallons of water into the Equus Beds aquifer during 2007–2012 as part of Phase I recharge of the Artificial Storage and Recovery project. This report, prepared in cooperation by the U.S. Geological Survey and the city of Wichita, Kansas, summarizes Little Arkansas River (source-water for artificial recharge) andEquus Beds aquifer water quaWater quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012
This fact sheet describes baseline water quality of the Equus Beds aquifer and Little Arkansas River and water-quality effects of artificial recharge by the city of Wichita associated with Phase I (2007–present) of the Aquifer Storage and Recovery project. During 1995 through 2012, more than 8,800 surface water and groundwater water-quality samples were collected and analyzed for more than 400 comStatus of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, 2012 to 2014
Development of the Wichita well field in the Equus Beds aquifer in southwest Harvey County and northwest Sedgwick County began in the 1940s to supply water to the city of Wichita. The decline of water levels in the Equus Beds aquifer was noted soon after the development of the Wichita well field began. Development of irrigation wells began in the 1960s. City and agricultural withdrawals led to subPreliminary simulation of chloride transport in the Equus Beds aquifer and simulated effects of well pumping and artificial recharge on groundwater flow and chloride transport near the city of Wichita, Kansas, 1990 through 2008
The Equus Beds aquifer in south-central Kansas is a primary water-supply source for the city of Wichita. Water-level declines because of groundwater pumping for municipal and irrigation needs as well as sporadic drought conditions have caused concern about the adequacy of the Equus Beds aquifer as a future water supply for Wichita. In March 2006, the city of Wichita began construction of the EquusRevised shallow and deep water-level and storage-volume changes in the Equus Beds Aquifer near Wichita, Kansas, predevelopment to 1993
Beginning in the 1940s, the Wichita well field was developed in the Equus Beds aquifer in southwestern Harvey County and northwestern Sedgwick County to supply water to the city of Wichita. The decline of water levels in the aquifer was noted soon after the development of the Wichita well field began. Development of irrigation wells began in the 1960s. City and agricultural withdrawals led to subsIrrigation trends in Kansas, 1991-2011
This fact sheet examines trends in total reported irrigation water use and acres irrigated as well as irrigation water use by crop type and system type in Kansas for the years 1991 through 2011. During the 21-year period, total reported irrigation water diversions varied substantially from year to year as affected primarily by climatic fluctuations. Total reported acres irrigated remained comparatSimulation of groundwater flow, effects of artificial recharge, and storage volume changes in the Equus Beds aquifer near the city of Wichita, Kansas well field, 1935–2008
The Equus Beds aquifer is a primary water-supply source for Wichita, Kansas and the surrounding area because of shallow depth to water, large saturated thickness, and generally good water quality. Substantial water-level declines in the Equus Beds aquifer have resulted from pumping groundwater for agricultural and municipal needs, as well as periodic drought conditions. In March 2006, the city of - Web Tools
Below are data or web applications associated with this project.
- Partners
Below are partners associated with this project.