News Release

Effects of Equus Beds Groundwater Recharge Project on Water Quality are Minimal

In 1992, the City of Wichita implemented a strategy to preserve the City’s future water supply and address declining water levels in the Equus Beds aquifer that have occurred since the 1940’s.  The Equus Beds aquifer is one of the primary sources of water supply for the City of Wichita and surrounding areas in south-central Kansas.   As part of the strategy, the City of Wichita began the Equus Beds Ground-Water Recharge Demonstration Project.

A cooperative effort between the city of Wichita and the U. S. Geological Survey (USGS) began in 1995 to study the effects of artificial recharge on water quality.  Artificial recharge, as part of the Equus Beds Ground-Water Recharge Project, involved capturing flows larger than base flow from the Little Arkansas River and recharging the water to the Equus Beds aquifer by means of infiltration or injection.  Artificial recharge of the Equus Beds aquifer will augment the City of Wichita’s future water supply needs and help preserve all existing aquifer uses from degradation of the aquifer from salt water migration, by increasing water levels in the aquifer. 

More than 5,000 water-quality samples collected during 1995-2004 from ground- and stream-water sites were used to describe the effects of artificial recharge processes on water quality. Water from several wells at different sites near the Little Arkansas River were analyzed for more than 400 chemicals.  Chloride and atrazine concentrations in the river exceeded the EPA drinking water standards 30 percent of the time from 1999-2004; atrazine concentrations in groundwater were much less than the standard; and large, naturally occurring arsenic concentrations in groundwater exceeded EPA standards.  Artificial recharge did not substantially change the aquifer geochemistry at the demonstration project recharge sites. Additionally, results from models indicate that the origin of 75-80 percent of water in wells near the Little Arkansas River is from the river.

“Having valuable data is essential to making good management decisions because of the critical nature of this resource.  The city of Wichita will use the results of this study to rely more on surface water sources and treatment to minimize the potential effects of artificial recharge on the aquifer,” stated Jerry Blain, Superintendent of  Production and Pumping of Wichita Water Utilities.  “Artificial recharge of the aquifer will benefit all users by replenishing the aquifer and slow the migration of existing saltwater contamination from the Burrton oil field and the Arkansas River.” 

Information about the Equus Beds aquifer recharge project in Kansas can be found at:

http://ks.water.usgs.gov/studies/equus/

This new report for the Equus Beds aquifer is now available online at:

http://pubs.usgs.gov/sir/2007/5025/

Printed copies of Scientific Investigations Report 2007-5025, “Geochemical Effects of Induced Stream-Water and Artificial Recharge on the Equus Beds Aquifer, South-Central Kansas, 1995-2004,” by Heather C. Ross Schmidt, Andres C. Ziegler, and David L Parkhurst,  may be purchased from the USGS Information Services, Box 25286, Federal Center, Denver, Colo. 80225, or call 1-888-ASK-USGS. A limited number of copies are available from the USGS office in Lawrence, Kansas.

The USGS serves the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

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