New USGS modeling report describes chloride movement in the area's aquifer
Chloride contamination of Wichita, Kan.’s, water supply wells is inevitable unless actions are taken, according to U.S. Geological Survey (USGS) scientists and authors of a new modeling report describing chloride movement in the area's aquifer.
Possible actions include pumping to remove the plume of high-chloride groundwater, and increased artificial recharge of water into the aquifer to slow the movement of chloride. On the other hand, increased pumping of well water and agricultural water will increase the rate of chloride movement.
The USGS model was developed in cooperation with the city of Wichita to assist resource managers in making decisions on how to best protect the city’s water resources. If chloride levels are high, the water is less usable as a drinking water source and for crop irrigation without additional treatment.
Past oil and gas activities near Burrton, Kan., resulted in a plume of high-chloride groundwater northwest of the Wichita well field, which is an area that encompasses most of the groundwater wells used by the city of Wichita. The chloride plume is currently moving toward that well field, threatening the part of the Equus Beds aquifer that supplies water to city and agricultural users. A new report and animations simulating chloride movement are available online.
The USGS chloride-transport model was prepared as part of the city of Wichita’s Equus Beds Aquifer Storage and Recovery (ASR) project, an effort to increase the amount of groundwater storage and maintain the water quality in the aquifer by artificially recharging treated water from the Little Arkansas River into the aquifer.
The USGS model simulated chloride transport from 1990 to 2008, and was used to test how various theoretical well field management scenarios affect groundwater levels and chloride movement toward the Wichita well field.
USGS will continue to work with the city of Wichita to maintain and update the model as more data about the Equus Beds aquifer are collected.