Equus Beds Ground-Water Recharge Project

Index

Highlights

• Gallons of Water Recharged
• Ground-Water Quantity and Levels
• Changes in Ground-Water Storage
• Surface-Water Quantity
• Real-time Streamflow
• Water Quality
• Real-time Water Quality
• Regression Equations

Maps of Equus Beds Recharge Data-Collection Sites

• Little Arkansas River Basin
• Areal Assessment Wells

Publications

• Water Quality
• Ground Water

Additional Equus Beds Information

• Equus Beds Information Resource

Schematic of the artificial recharge process

Description of Study

The water supply for the city of Wichita, south-central Kansas comes from two primary sources; the Wichita well field, completed in the Equus Beds aquifer, and Cheney Reservoir. The available water supply for the city of Wichita must be increased to meet their future water needs into the 21^st century. Artificial recharge of the Equus Beds aquifer using above base flow from the Little Arkansas River is an alternative to meet future city water demand. Historical use of the Equus Beds aquifer for Wichita’s water supply and area agriculture has caused water level declines exceeding 35 ft in some areas. Because of decreased ground water levels, salt water migration from the Arkansas River and from past oil and gas activities near Burrton, Kansas threaten the water quality of the Equus Beds aquifer and artificial recharge could help deter this salt water migration.

The Equus Beds Ground-Water Recharge Demonstration project began in 1995 to determine if a full scale artificial recharge project was feasible. The primary purpose of the Equus Beds ground-water demonstration project was to evaluate ground-water recharge and source water recovery techniques, including the impacts on water quality, design criteria needed, and problems associated with infiltration of excess stream flow.  

Two different methods of retrieving the source water for artificial recharge were tested and three methods of artificial recharge were tested during the demonstration project. For one source water retrieval method the water is diverted from the Little Arkansas River by a pump that is installed in the river alluvium at the Halstead recharge system. The pumping action causes ground water levels in the riverbank to drop, thus allowing the river water to flow into the alluvium, which in turn is captured by the pump (capacity 1,000 gallons per minute) and piped to the Halstead Recharge site. The other method for retrieving source water is where it is directly diverted from the Little Arkansas River at the Sedgwick Recharge system. Because the water is taken directly from the surface water, the water is treated for organic compounds and sediment before it is artificial recharged to the aquifer.

The three methods evaluated for recharging the water to the aquifer were a direct injection well, a recharge trench, and recharge basins. The injection well, recharge basins, and recharge trench were in use at the Halstead recharge site and recharge basins were the method of recharge at the Sedgwick recharge site.

The Equus Beds ground-water demonstration project was funded through a cooperative effort between the City of Wichita and the U.S. Bureau of Reclamation. The United States Geological Survey (USGS), Groundwater Management District Number 2 (GMD2), and two engineering consultant firms also are contributing funds, expertise and personnel to complete, design, and study the effectiveness of the recharge demonstration project. Burns and McDonnell Engineering Consultants manage the overall project and engineering design for the City of Wichita. The USGS role in activities with the city of Wichita has been to determine water quantity and water quality conditions and to describe the water resources in the Equus Beds aquifer and the Little Arkansas River. USGS began data collection at the sites in the well field area in February 1995.

Since the completion of the demonstration phase of the project, monitoring of the water quantity and water quality has continued in the study area at monitoring wells throughout the area. Monitoring of the Little Arkansas River also has continued. An areal assessment for water levels and water quality in the Equus Beds aquifer is in progress. For the areal assessment seventy-six wells, which cover approximately 300 square miles north of the Arkansas River, are sampled for quality. The wells completed in the Equus Beds aquifer are both shallow and deep monitoring wells and will provide water quality information throughout the area.