Concentrations and loads of cadmium, lead, and zinc measured on the ascending and descending limbs of the 1999 snowmelt-runoff hydrographs for nine water-quality stations, Coeur d'Alene River basin, Idaho

Open-File Report 2000-310
Prepared in cooperation with U.S. Environmental Protection Agency
By:

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Abstract

The Remedial Investigation/Feasibility Study conducted by the U.S. Environmental Protection Agency within the Spokane River Basin of northern Idaho and eastern Washington included extensive data-collection activities to determine the nature and extent of trace-element contamination within the basin. The U.S. Geological Survey designed and implemented synoptic sampling of a high-flow runoff event at selected water-quality stations during the 1999 water year. The objective was to quantify spatial and temporal differences in constituent concentrations and loads over the ascending and descending limbs of a hydrograph depicting a high-flow runoff event. Discharge and water-quality data were collected during spring 1999 snowmelt runoff (May through early June) at nine water-quality stations, one on the North Fork Coeur d’Alene River and eight on the South Fork Coeur d’Alene River. The nine stations were sam- pled for whole-water recoverable and dissolved concentrations and loads of cadmium, lead, and zinc. The concentrations and loads sampled during the 1999 snowmelt-runoff event represented near-normal conditions, not flood conditions, in that the recurrence interval for discharge near the hydrograph peak was about 2 years. The general trend among the nine stations was an inverse relation between discharge and dissolved concentrations of cadmium, lead, and zinc, and a direct relation between discharge and whole-water recoverable concentrations of these constituents. The smallest loads of dissolved and whole-water recoverable cadmium, lead, and zinc were measured at South Fork Coeur d’Alene River above Deadman Gulch; constituent concentrations at this site were some of the smallest among those sampled, and discharge was also relatively small. The largest loads of dissolved and whole-water recoverable cadmium, lead, and zinc were measured at South Fork Coeur d’Alene River at Pinehurst; constituent concentrations at this site were large and discharge was the second-largest of all the discharge measurements. Hysteresis effects on concentrations and loads over the ascending and descending limbs of the snowmelt-runoff hydrograph were quite apparent, especially for whole-water recoverable constituents. Hysteresis is present when a property, such as constituent concentration or load, has different values for a given discharge over the ascending and descending limbs of a hydrograph. During this study, loads of whole-water recoverable constituents on the ascending limb were between 1.5 and 3.6 times larger than those mea- sured on the descending limb at nearly equal discharge. In contrast, dissolved constituents showed minimal hysteresis effects.

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Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Concentrations and loads of cadmium, lead, and zinc measured on the ascending and descending limbs of the 1999 snowmelt-runoff hydrographs for nine water-quality stations, Coeur d'Alene River basin, Idaho
Series title Open-File Report
Series number 2000-310
ISBN 0094-9140
DOI 10.3133/ofr00310
Year Published 2001
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Idaho Water Science Center
Description iv, 42 p.
Country United States
State Idaho
Other Geospatial Bunker Hill Superfund;South Fork
Projection Albers Equal-Area
Scale 100000