Clark Fork near Galen

MONTANA PROJECTS

• Major Projects
  • Tongue River Monitoring
  • Clark Fork Monitoring
  • Diel Metal Cycling

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CLARK FORK WATER-QUALITY MONITORING

Home Project Description Retrieve water-quality data Statistical summaries of water-quality data Supplemental sampling in lower Clark Fork basin Links    Reports Contacts

STATISTICAL SUMMARIES OF WATER QUALITY DATA

Statistical summaries of water-quality data are presented for sites in the upper Clark Fork long-term monitoring network to describe the range of values and allow data comparisons among sites.  Statistical summary tables are provided for two time periods: 1) period of record and 2) water year 2008.  Comparing values for these two periods can indicate the degree of similarity or difference between long-term and recent water-quality conditions.

Tables for the period of record include the first year of sampling (1985 or later) through the most recent water year for which the water-quality data have been approved.  Periods of record may vary among sites as the result of different starting dates, discontinuation of sampling, or modifications to the sampling program.  Tables for water year 2008 represent the most recent year of approved water-quality data.  Provisional water-quality data for samples collected in the current water year (2009) are not included in the summaries.  

The statistical summaries include approved data for only the routine samples collected as part of the upper Clark Fork long-term monitoring program.  Additional samples obtained for short-term supplemental sampling programs, primarily at the three sites bracketing Milltown Reservoir (Clark Fork at Turah Bridge near Bonner, Blackfoot River near Bonner, and Clark Fork above Missoula) are not included in the summaries.  The supplemental samples typically targeted high flows or periods of reservoir drawdowns to better evaluate increased sediment and metals transport resulting from scour of bottom sediments from the area of Milltown Reservoir.  Consequently, the extra samples could bias the statistical distribution of values at the three sites and make the data less comparable to other sites in the network where supplemental samples were not collected.  Data for all routine and supplemental water-quality samples collected for the Clark Fork monitoring program can be retrieved through the Retrieve Water-Quality Data page of this Web site.

TABLES

• Period of Record (Historical Thru 2008)
• Water Year 2008 (2008 Summary)