Geology topics

Research about Boulder River watershed

Source-linked reports with geographic coverage including Boulder River watershed.

5 recordsLinked to original sources

USGS2009

Metal contamination and post-remediation recovery in the Boulder River watershed, Jefferson County, Montana

The legacy of acid mine drainage and toxic trace metals left in streams by historical mining is being addressed by many important yet costly remediation efforts. Monitoring of environmental conditions frequently is not performed but is essential to evaluate remediation effectiveness, determine whether clean-up goals have been met, and assess which remediation strategies are most effective. Extensive pre- and post-remediation data for water and sediment quality for the Boulder River watershed in southwestern Montana provide an unusual opportunity to demonstrate the importance of monitoring. The most extensive restoration in the watershed occurred at the Comet mine on High Ore Creek and resulted in the most dramatic improvement in aquatic habitat. Removal of contaminated sediment and tailings, and stream-channel reconstruction reduced Cd and Zn concentrations in water such that fish are now present, and reduced metal concentrations in streambed sediment by a factor of c. 10, the largest improvement in the district. Waste removals at the Buckeye/Enterprise and Bullion mine sites produced limited or no improvement in water and sediment quality, and acidic drainage from mine adits continues to degrade stream aquatic habitat. Recontouring of hillslopes that had funnelled runoff into the workings of the Crystal mine substantially reduced metal concentrations in Uncle Sam Gulch, but did not eliminate all of the acidic adit drainage. Lead isotopic evidence suggests that the Crystal mine rather than the Comet mine is now the largest source of metals in streambed sediment of the Boulder River. The completed removal actions prevent additional contaminants from entering the stream, but it may take many years for erosional processes to diminish the effects of contaminated sediment already in streams. Although significant strides have been made, additional efforts to seal draining adits or treat the adit effluent at the Bullion and Crystal mines would need to be completed to achieve the desired restoration.

Montana↗

USGS2007

Concentrations of metals in water, sediment, biofilm, benthic macroinvertebrates, and fish in the Boulder River watershed, Montana, and the role of colloids in metal uptake

To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs ), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 μg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 μg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits.

Montana↗

USGS2000

Analytical results for total-digestions, EPA-1312 leach, and net acid production for twenty-three abandoned metal-mining related wastes in the Boulder River watershed, northern Jefferson County, Montana

Introduction Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana, have been implicated in their detrimental effects on water quality with regard to acid generation and toxic-metal solubilization during snow melt and storm water runoff events. This degradation of water quality is defined chiefly by the “Class 1 Aquatic Life Standards” that give limits for certain dissolved metal concentrations according to water alkalinity. Veins enriched in base- and precious metals were explored and mined in the Basin, Cataract Creek, and High Ore Creek drainages over a period of more than 70 years. Extracted minerals included galena, sphalerite, pyrite, chalcopyrite, tetrahedrite and arsenopyrite. Most of the metal-mining wastes in the study area were identified and described by the Montana Bureau of Mines and Geology. In 1997, the U.S. Geological Survey collected 20 composite samples of mine-dump or tailings waste from ten sites in the Basin and Cataract Creek drainages, and two samples from one site in the High Ore Creek drainage. Desborough and Fey presented data concerning acid generation potential, mineralogy, concentrations of certain metals by energy-dispersive X-ray fluorescence (EDXRF), and trace-element leachability of mine and exploration wastes from the ten sites of the Basin and Cataract Creek drainages. The present report presents total-digestion major- and trace-element analyses, net acid production (NAP), and results from the EPA-1312 synthetic precipitation leach procedure (SPLP) performed on the same composite samples from the ten sites from the Basin and Cataract Creek drainages, and two composite samples from the site in the High Ore Creek drainage.

Montana↗

USGS2000

Chemical data and lead isotopic compositions of geochemical baseline samples from streambed sediments and smelter slag, lead isotopic compositions in fluvial tailings, and dendrochronology results from the Boulder River watershed, Jefferson County, Montana

Introduction As a part of the U.S. Geological Survey Abandoned Mine Lands Initiative, metal-mining related wastes in the Boulder River study area in northern Jefferson County, Montana, have been evaluated for their environmental effects. The study area includes a 24-km segment of the Boulder River in and around Basin, Montana and three principal tributaries to the Boulder River: Basin Creek, Cataract Creek, and High Ore Creek. Mine and prospect waste dumps and mill wastes are located throughout the drainage basins of these tributaries and in the Boulder River. Mine-waste material has been transported into and down streams, where it has mixed with and become incorporated into the streambed sediments. In some localities, mine waste material was placed directly in stream channels and was transported downstream forming fluvial tailings deposits along the stream banks. Water quality and aquatic habitat have been affected by trace-element-contaminated sediment that moves from mine wastes into and down streams during snowmelt and storm runoff events within the Boulder River watershed. Present-day trace element concentrations in the streambed sediments and fluvial tailings have been extensively studied. However, in order to accurately evaluate the impact of mining on the stream environments, it is also necessary to evaluate the pre-mining trace-element concentrations in the streambed sediments. Three types of samples have been collected for estimation of pre-mining concentrations: 1) streambed sediment samples from the Boulder River and its tributaries located upstream from historical mining activity, 2) stream terrace deposits located both upstream and downstream of the major tributaries along the Boulder River, and 3) cores through sediment in overbank deposits, in abandoned stream channels, or beneath fluvial tailings deposits. In this report, we present geochemical data for six stream-terrace samples and twelve sediment-core samples and lead isotopic data for six terrace and thirteen core samples. Sample localities are in table 1 and figures 1 and 2, and site and sample descriptions are in table 2. Geochemical data have been presented for cores through fluvial tailings on High Ore Creek, on upper Basin Creek, and on Jack Creek and Uncle Sam Gulch. Geochemical and lead isotopic data for modern streambed-sediment samples have been presented by Fey and others. Lead isotopic determinations in bed sediments have been shown to be an effective tool for evaluating the contributions from various sources to the metals in bed sediments. However, in order to make these calculations, the lead isotopic compositions of the contaminant sources must also be known. Consequently, we have determined the lead isotopic compositions of five streambed-sediment samples heavily contaminated with fluvial mine waste immediately downstream from large mines in the Boulder River watershed in order to determine the lead isotopic signatures of the contaminants. Summary geochemical data for the contaminants are presented here and geochemical data for the streambed-sediment samples are given by Fey and others. Downstream from the Katie mill site and Jib tailings, fluvial deposits of mill tailings are present on a 10-m by 50-m bar in the Boulder River below the confluence with Basin Creek. The source of these tailings is not known, but fluvial tailings are also present immediately downstream from the Katie mill site, which is immediately upstream from the confluence with Basin Creek. Nine cores of fluvial tailings from this bar were analyzed. Dendrochronology samples were taken at several stream terrace localities to provide age control on the stream terrace deposits. Trees growing on the surfaces of stream terraces provide a minimum age for the terrace deposits, although floods subsequent to the trees' growth could have deposited post-mining overbank deposits around the trees. Historical data were also used to provide estimates of minimum ages of cultural features and to bracket the age of events.

Montana↗

USGS1999

Chemical data and lead isotopic compositions in stream-sediment samples from the Boulder River watershed, Jefferson County, Montana

Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana, have been evaluated for their environmental effects as a part of the U.S. Geological Survey Abandoned Mine Lands Project. Many mine and prospect waste dumps, and mill wastes are located in the drainage basins of Basin Creek, Cataract Creek, and High Ore Creek, the three major tributaries to the Boulder River in the study area. Throughout the study area, mine-waste material has been transported into and down streams, where it mixes with and becomes incorporated into the bed sediments. In some locations, waste material was placed by mine operators directly in stream channels, and has been transported downstream forming fluvial tailings deposits along the stream banks. Water quality and aquatic habitat have been affected by acid generation and toxic-metal mobility during snowmelt and storm water runoff events. Colloids formed by the raising of pH downstream from these mine sites sorb metals contributing to the high concentrations observed in both bed and suspended sediments within the watershed. This report presents geochemical data for bed sediments from 67 sites and lead isotope data for 59 sites. Also included are geochemical data for seven suspended-sediment samples, and one smelter slag sample.

Montana↗