Little Arkansas River trace metal investigation

Abstract

The Little Arkansas River originates in central Kansas in areas of high agriculture near the town of McPherson and flows south through increasing urbanization until joining the Arkansas River in Wichita Ks. With population increases between Valley Center and Wichita (KS), river contamination increases, and becomes listed as an impaired waterway endangering aquatic life and limiting resource use. Using data collected by the Environmental Protection Agency from multiple monitoring stations, accessed through the EPA Storet data repository, analysis determined heavy metals of interest using descriptive statistics and hardness dependent calculations for acute and chronic aquatic life water criteria. Bank deposits were also collected throughout the basin at USGS gauging stations and at other accessible locations. Bank sediments were dried, pulverized, and pressed into pellets using boric acid binder for heavy metal analysis using x-ray florescence. The combined results indicated spatial variations of metal concentrations related to surrounding land use. As urbanization increases river features are degraded and copper, chromium, lead, nickel, and zinc increase to concentrations that periodically exceed the calculated standards.