Skip Links

USGS - science for a changing world

Scientific Investigations Report 2007-5262

Prepared in cooperation with the Midnite Uranium Mine Natural Resource Trustee Council

Determination of Premining Geochemical Background and Delineation of Extent of Sediment Contamination in Blue Creek Downstream from Midnite Mine, Stevens County, Washington

By Stanley E. Church, Frederick E. Kirschner, LaDonna M. Choate, Paul J. Lamothe, James R. Budahn, and Zoe Ann Brown

Thumbnail of and link to report PDF (11.4 MB)Download Publication
Scientific Investigations Report
2007-5262 PDF (11.4 MB)

Geochemical and radionuclide studies of sediment recovered from eight core sites in the Blue Creek flood plain and Blue Creek delta downstream in Lake Roosevelt have provided a stratigraphic geochemical record of contamination from uranium mining at the Midnite Mine. Cores provided sufficient data to determine the premining geochemical background, contamination by uranium during the mining period, and postmining metal concentrations that are lower than during the mining period, but elevated relative to premining geochemical background. These data have been used to delineate the extent of contaminated sediment in Blue Creek cove along the thalweg of Blue Creek into Lake Roosevelt.

Version 1.0

Posted March 2008

Suggested citation:

Church, S.E., Kirschner, F.E., Choate, L.M., Lamothe, P.J., Budahn, J.R., and Brown, Z.A., 2008, Determination of premining geochemical background and delineation of extent of sediment contamination in Blue Creek downstream from Midnite Mine, Stevens County, Washington: U.S. Geological Survey Scientific Investigations Report 2007–5262, 177 p.




Purpose and Scope


Regional Setting

Mine-Site Geology

Previous Work

Stream-Sediment Studies

Data from Sediment from Lake Roosevelt

Water-Quality Data

Sampling and Preparation Methods

Stream-Sediment Samples, Blue Creek Delta

Terrace- and Stream-Sediment Core Samples

Description of Terrace Core Sampling Sites

Analytical Methods

Sediment-Sample Digestion and Analytical Methods

Quality Assurance—Quality Control Data

Gamma-Ray Spectrometry Methods

Quality Assurance—Quality Control Data

Statistical Methods

Results and Discussion

137Cs Data from Cores 06MM01 and 06MM08

Geochemical Data from Terrace Cores, Blue Creek

Sediment Geochemistry, Core 06MM08

Radionuclide Data, Core 06MM08

Sediment Geochemistry, Core 06MM06

Sediment Geochemistry, Core 06MM05

Sediment Geochemistry, Cores from the Blue Creek Delta

Sediment Geochemistry, Core 06MM03

Sediment Geochemistry, Core 06MM04

Sediment Geochemistry, Core 06MM02

Sediment Geochemistry, Core 06MM01

Radionuclide Data, Core 06MM01

Premining Geochemical Background Upstream of the Midnite Mine

Comparison of the 1975 USGS Sediment Geochemical Data with Geochemical Data from the 1970s Sample Intervals in 2006 Cores

Geochemical Data from the Blue Creek Delta

Geochemical Contamination from the Spokane River in Lake Roosevelt

Premining Geochemical Background Data, Blue Creek Delta

Data from Surface-Sediment Sites, Blue Creek Delta

Summary of Geochemical Data


References Cited

Appendix A. Tables Showing Sample Descriptions, Locations, Weights of Sieved Core Segments by Grain Size; Tables Showing Analytical Data from Cores and Sediment Used in Study; Tables Showing Geochemical Background Statistical Data and Calculations, Including Statistical Description in Graphical Form for Each Element; and Photographs of Cores

Appendix B. Standard Operating Procedure for Sampling Sediments with Driven Core Sediment Sampler (DCSS) on the Spokane Indian Reservation (SOP_DCSS)


Document Accessibility: Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Acrobat Reader or similar software is required to view it. Download the latest version of Acrobat Reader, free of charge or go to for free tools that allow visually impaired users to read PDF files.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Thursday, December 01 2016, 08:01:04 PM