Uneven Distribution of Heavy Metals in Shoreline Sediments of Spring Meadow Lake, Lewis and Clark County, Montana

Abstract

The objective of this study was to determine the site-specific metal concentrations in the shoreline sediments of Spring Meadow Lake, Montana. A previous study had determined that there were elevated levels of manganese, lead, copper, iron, zinc, and cadmium in the sediment. In the present study, ten equally spaced areas were sampled around the lake to determine if a specific location of contamination existed. Samples were digested with nitric acid and analyzed by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). After a preliminary analysis of the samples revealed that most of the metal contamination was located toward the east side of the lake, ten additional samples were collected and analyzed from that area. The results indicated that two sites with elevated levels of metals existed on the east side of the lake. During the early 1900’s Northwestern Metals Co. (also known as the New-York-Montana and Engineering Co.) operated an ore processing facility at this site. A connection between the elevated metal levels at the two sites and the operations of the ore processing facility is evaluated.