Central Plains Center for Bioassessment

Assessment of Selenium Levels in Water, Bottom Sediment, and Biota of Arkansas River in Southwestern Kansas (Kansas Department of Health and Environment)

Arkansas River near Coolidge.
Date January 2005 - January 2007
Contact Debbie Baker
Location Arkansas River between Kansas-Colorado state line and Garden City, Kansas


About the Arkansas River Project

Selenium was the only trace constituent associated with irrigation drainage that was observed to be at elevated levels in water, bottom sediment, and biota within the Upper Arkansas River basin. Selenium is usually associated with the clay content in rocks and so high concentration of selenium is often found in shales. Cretaceous marine shales and limestone are exposed extensively in the watershed. Thus, the main natural selenium source is runoff from the shales. Selenium becomes concentrated along the Arkansas River due to evapotranspiration and leaching of selenium by irrigation.

The most recent studies related to selenium levels in the Arkansas River were performed by USGS in the late 1980’s and by KGS in the late 1990’s. Thus, there is a need to assess the current degree of selenium impairment in the upper Arkansas River and need for TMDL for selenium in this region.

This study seeks to assess selenium levels in water, bottom sediment, and biota of the Arkansas River between Kansas-Colorado state line and Garden City, Kansas. Multiple sites along the Arkansas River will be sampled in late summer and early winter of 2005 and in mid-spring of 2006. Seasonal and cross-media variability of selenium levels will be evaluated. In addition, collected stream water is also analyzed for nutrients and chlorophyll a. Periphyton samples are collected from the dominant substrate of the river (sand).


We sampled the Arkansas River at sites near Lakin, Kendall, and Coolidge, KS in early September and in mid-December 2005 (Ark_data.xls).

We sampled the Arkansas River in 2006 (Ark_Riv_data.xls).

We sampled Shunganunga Creek in 2006 (Shunga_Crk_data.xls).

Analysis, Results, or Reports

Biological Assessment of Existing TMDL Stream (Contract 2005-TMDL4) -- Covering activities from July to November 2005 (Ark_River Report.pdf).

Biological Assessment of TMDL Stream (Contract 2006-TMDL3) 2006 (2006-TMDL3 report.pdf).

Maps, Images, or Photos

Arkansas River Sampling Sites

(click here for larger image)

Arkansas River near Coolidge
Arkansas River near Kendall
Arkansas River near Lakin