Limiting atrazine in Little Arkansas River Watershed
(Note: Graber wrote the following article based on a news release by Kaitlin Morgan, K-State Research and Extension communications specialist.)
Located in central Kansas, the Little Arkansas River watershed is one of the most intensive agricultural watersheds in the state, with 97 percent of its land area in agricultural production.
Many of these acres are used for either corn or grain sorghum production and a majority of producers in the watershed use atrazine for control of broadleaf weeds and grasses.
Because atrazine is water soluble, atrazine can run off fields during rainfall, sometimes creating a surface water quality issue in the Little Arkansas River watershed and other heavily farmed watersheds.
Spring and early summer are periods of heavy atrazine application due to corn and sorghum planting. As a result, the concentration of atrazine in the surface waters during this season can sometimes rise above the drinking water maximum contaminant level and the aquatic life standards for atrazine set by the U.S. Environmental Protection Agency.
Wichita has an aquifer re-charge project in which they are attempting to capture water during high flow conditions of the Little Arkansas River and inject it back into the groundwater aquifer for later use.
Before it can be injected, the water must meet drinking water standards. However, most municipal water treatment plants do not remove atrazine and other pesticides because it requires an activated carbon treatment system to the treatment process, which increases the cost of the facility and the day-to-day cost of water treatment.
The Little Arkansas Watershed is currently the only one focusing on this in Kansas. Other parts of the state may not be aware of some of the issues with atrazine, but in the Little Arkansas Watershed there is a heightened responsiveness because of the city of Wichita.
Incentive for change
In 2004, a local group of watershed stakeholders developed a plan to restore and protect the surface waters of the Little Arkansas River watershed. The main goal of their Watershed Restoration and Protection Strategy (WRAPS) is to encourage farmers to minimize atrazine loss from crop fields, thereby reducing atrazine runoff to surface waters to levels that meet water quality standards.
The WRAPS team knew atrazine runoff couldn’t be totally eliminated, but if atrazine runoff could be kept at a minimum and spikes in atrazine concentration could be prevented, that would be a tremendous benefit to the city of Wichita in terms of the amount of money it spends treating the water.