A comprehensive field and laboratory approach to the ecological risk
assessment for the Milltown Reservoir-Clark Fork River Sediments
site, a Superfund site in the Rocky Mountains of Montana, was
conducted previously. The risk assessment addressed concerns over the
ecological impacts of upstream releases of mining wastes to fisheries
of the upper Clark Fork River and the benthic and terrestrial habitats
further downstream in Milltown Reservoir. The risk characterization
component of the process integrated results from a triad of
information sources: (a) chemistry studies of environmental media to
identify and quantify exposures of terrestrial and aquatic organisms
to site-related contaminants; (b) ecological or population studies of
terrestrial vegetation, birds, benthic communities, and fish; and (e)
in situ and laboratory toxicity studies with terrestrial and aquatic
invertebrates and plants, small mammals, amphibians, and fish exposed
to contaminated surface water, sediments, wetland soils, and food
sources. Trophic transfer studies were performed on waterfowl,
mammals, and predatory birds using field measurement data on metals
concentrations in environment media and lower troposphere food
sources. Studies with sediment exposures were incorporated into the
Sediment Quality Triad approach to evaluate risks to benthic ecology.
Overall results of the wetland and terrestrial studies suggested that
acute adverse biological effects were largely absent from the wetland;
however, adverse effects to reproductive, growth, and physiological
end points of various terrestrial and aquatic species were related to
metals exposures in more highly contaminated depositional areas.
Feeding studies with contaminated diet collected from the upper Clark
Fork River indicated that trout may be at high risk from elevated metals
concentrations in surface water, sediment, and aquatic invertebrates.
Integration of chemical analyses with toxicological and ecological
evaluations of metal effects on the wetland and fishery has provided
an important foundation for environmental decisions at this site.
Purpose:
To Integrate chemical analyses with toxicological and ecological
evaluations of metal effects on the wetland and fishery in order to provide
an important foundation for environmental decisions at this site.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19910722
Ending_Date: 19910919
Currentness_Reference: From principal investigator notes
Status:
Progress: Complete
Maintenance_and_Update_Frequency: none planned
Spatial_Domain:
Description_of_Geographic_Extent:
The Clark Fork River, located in southwestern Montana, is the largest
tributary of the Columbia River in the northwestern United States. The
upper Clark Fork River also supports a cold-water trout fishery. The
upper Clark Fork River from the Butte and Anaconda area to at least
230 km downstream at Milltown Reservoir is contaminated with As, Cu,
Cd, Pb, Mn, and Zn primarily from mining activities. Silver Bow
Creek, the upper Clark Fork River, and Milltown Reservoir have been
designated Superfund sites by the U.S. Environmental Protection Agency
because of metal-contaminated bottom sediments and arsenic (As) in
drinking water.
Note: the following coordinates are taken from a road atlas based
on the above description.
U.S. Geological Survey
Biological Resources Division
[formerly: National Biological Service,]
Columbia Environmental Research Center
[formerly: Environmental and Contaminants Research Center]
[formerly: Midwest Science Center]
Characterization of Ecological Risks at the Milltown
Reservoir - Clark Fork River Sediments Superfund site, Montana
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13:2043-2058
Cross_Reference:
Citation_Information:
Originator: Besser, J. M. et al.
Publication_Date: 1995
Title:
Effects of Spatial and Temporal Variation of Acid-Volatile
Sulfide on the Bioavailability of Copper and Zinc in Freshwater Sediments
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 15:286-293
Cross_Reference:
Citation_Information:
Originator: Canfield, T. J. et al.
Publication_Date: 1994
Title:
Use of Benthic Invertebrate Community Structure and the
Sediment Quality Triad to Evaluate Metal-Contaminated Sediment in the
Upper Clark Fork River, Montana
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13:1994-2012
Cross_Reference:
Citation_Information:
Originator: Ingersoll, C. G. et al
Publication_Date: 1994
Title:
Bioaccumulation of metals by Hyalella Azteca exposed to
contaminated sediments from the upper Clark Fork River, Montana
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13:2013-2020
Cross_Reference:
Citation_Information:
Originator: Brumbaugh, W. G.
Publication_Date: 1994
Title:
Chemical Characteristics of Sediments and Pore Water From
the Upper Clark Fork River and Milltown Reservoir, Montana
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13:1971-1983
Cross_Reference:
Citation_Information:
Originator: Kemble, N. E. et al
Publication_Date: 1994
Title:
Toxicity of Metal-Contaminated Sediments from the upper
Clark Fork River, Montana, to aquatic invertebrates and fish in
laboratory exposures.
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13:1985-1997
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: unknown
Logical_Consistency_Report: unknown
Completeness_Report: unknown
Lineage:
Methodology:
Methodology_Type: field
Methodology_Description:
Benthic invertebrates were collected from depositional areas at each
of six Clark Fork River Stations. All benthos samples were collected
before collection of sediment samples for chemistry and toxicity
testing in an effort to minimize disturbance of the sediments and
associated invertebrates. Five replicate Ponar samples were taken at
each station within a 100-m2 area. Each replicate consisted of one
grab sample. Benthic samples were taken from about the upper 6 cm of
the sediment surface. Samples were sieved through an ASTM no.l 30
sieve (533 micrometers); retained sieve materials were transferred to
1-L glass jars, preserved in buffered 10% formalin, and transported to
the laboratory. Sediment samples for toxicity testing and sediment
chemistry were similarly collected from the upper 6 cm. of sediment in
depositional zones with a petite Ponar grab or polypropylene scoop.
Each toxicity/chemistry sample was a composite of a minimum of 10
grabs/station.
Methodology:
Methodology_Type: taxonomic identification
Methodology_Description:
Before sorting, benthic samples were rinsed with tap water to remove
formalin and excess silt or mud. The samples were then drained of
excess water, returned to the original jars, filled with 95% ethanol,
and allowed to soak for at least 24 hours to extract volatile
compounds. After the 24-h extraction period, each sample was rinsed
again with tap water to remove the ethanol and volatile compounds, and
fresh 95% ethanol was added to each sample. Samples with more than
200 ml of retained material were split into eight equal subsamples.
Four of the eight subsamples were sorted and enumerated. The
remaining four subsamples were placed in separate containers and
archived. Samples that were not split were completely sorted.
Methodology:
Methodology_Type: field
Methodology_Description:
Benthic invertebrates were collected from depositional areas at each
of six Clark Fork River Stations. All benthos samples were collected
before collection of sediment samples for chemistry and toxicity
testing in an effort to minimize disturbance of the sediments and
associated invertebrates. Five replicate Ponar samples were taken at
each station within a 100-m2 area. Each replicate consisted of one
grab sample. Benthic samples were taken from about the upper 6 cm of
the sediment surface. Samples were sieved through an ASTM no.l 30
sieve (533 micrometers); retained sieve materials were transferred to
1-L glass jars, preserved in buffered 10% formalin, and transported to
the laboratory. Sediment samples for toxicity testing and sediment
chemistry were similarly collected from the upper 6 cm. of sediment in
depositional zones with a petite Ponar grab or polypropylene scoop.
Each toxicity/chemistry sample was a composite of a minimum of 10
grabs/station.
Methodology:
Methodology_Type: physical characterizations of sediment
Methodology_Description:
Sediment samples from each station were subsampled within 1 week of
collection from field. Sediment subsamples were characterized for the
following physical variables: percentage water, particle size, cation
exchange capacity, organic carbon, inorganic carbon, and ash-free dry
weight.
Methodology_Citation:
Citation_Information:
Originator: Kemble N. E. et al
Publication_Date: 1993
Title: Sediment Toxicology
Publication_Information:
Publication_Place: Helena, MT
Publisher: National Technical Information Service
Methodology_Type: Chemical characterizations of sediment
Methodology_Description:
Sediment subsamples were characterized for the following chemical
variables: acid-volatile sulfides (AVS), reducible iron and manganese,
metals, and organic contaminants.
Methodology_Citation:
Citation_Information:
Originator: Brumbaugh, W. G. et al
Publication_Date: 1994
Title:
Chemical characterization of sediments and pore water
from the upper Clark Fork River and Milltown Reservoir.
Series_Information:
Series_Name: Environmental Toxicology and Chemistry
Issue_Identification: 13(12)
Methodology_Type: toxicity tests on sediments
Methodology_Description:
Whole-sediment toxicity tests were conducted with the following
tests and species: amphipods (Hyalella azteca), midges (Chironomus
riparius), cladocerans (Daphnia magna), and rainbow trout
(Oncorhynchus mykiss).