Site Locations

The primary study sites for the Upper Arkansas Toxics Project are located in the headwaters of the Arkansas River Basin near Leadville, Colorado. From 1986 to 1995, a series of studies were conducted to quantify the physical, chemical, and biological processes affecting trace metal fate and transport. These studies are described below. Additional studies conducted in other watersheds from 1996 to present are summarized on the ' Synoptic Studies' page.

 

St. Kevin Gulch

Date	Purpose
1986	Watershed characterization and definition of diel variation of iron species
1987	Define rates of chemical reactions in comparison to rates of hydrologic transport
1987-91	Evaluate cycling and retention of trace metals in a wetland receiving acid mine drainage (K. Walton-Day Ph.D. dissertation)
1987-91	Evaluate factors influencing metal sorption onto iron-rich sediment (K.S. Smith Ph.D. dissertation)
1987-92	Evaluate factors influencing the mobility of suspended sediments (J.F. Ranville Ph.D. dissertation)
1988	pH modification experiment to identify reactions analogous to remediation
1989	Characterize streamflow losses to alluvial fan using multiple tracer injections
1990	Definition of hyporheic flow paths
1991	High flow synoptic study; more definition of hyporheic flow
1993-1999	Evaluate effects of stress from mine drainage on ecosystem function (D.K. Niyogi Ph.D. dissertation)
1993	Extensive pH modification experiment including iron speciation and hyporheic samples; tracer injected into mine dump to define flow paths to stream
1994	Diversion experiment to simulate remediation in a short reach near mine dump
1995	Define photoproducts for iron reduction

 

Upper Arkansas River

Date	Purpose
1992	Diel study of California Gulch and the upper Arkansas River downstream from California Gulch to identify photoreduction at higher pH