METAL CONTAMINATION OF THE CLARK FORK RIVER, WESTERN MONTANA: A COMPARATIVE STUDY OF METAL CONCENTRATIONS IN FINE-GRAINED BED SEDIMENT AND SOURCE MATERIAL

Open pit mining in the Butte area has caused significant metal contamination of the fine-grained bed sediments throughout the Clark Fork River basin. The headwaters of the Clark Fork River, Warm Springs Creek and Silver Bow Creek, accumulated waste deposits from past mining operations. Large quantities of this mine waste, called "tailings",laden with heavy metals, were subsequently redistributed by river flow. As a result the floodplain of the Clark Fork River serves as a source of contamination to the river channel. River banks are subjected to erosional processes which release tailings into the river channel where they are transported to areas of deposition on the river bed. The nature of the river to carry and deposit sediment has caused widespread contamination throughout the upper Clark Fork River basin.

In my study I will examine the relationship between the concentrations of metals in the source material(river bank) with that of the depositional areas(river bed). The upper Clark Fork River basin has been established a Superfund site. While extensive remediation has not yet begun, local projects such as this help to understand the extent and nature of the contamination and requirements for remediation.