Scientific Investigations Report 2008–5168
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2008–5168
Table 5. Selected trace-metal loads and errors measured at three gaging stations near Coeur d’Alene Lake, Idaho, calendar years 1991–92 and water years 2004–06.
[Sampling locations are shown in figure 1. Sampling locations on the St. Joe and Spokane Rivers changed between the 1991–92 and 2004–06 studies. Few differences in trace-metal inputs are expected between sampling locations. Locations sampled in 1991–92 study: St. Joe River, USGS gaging station 12415075, St. Joe River at St. Maries; Spokane River, USGS gaging station 12419000, Spokane River near Post Falls. Locations sampled in 2004–06 study: St. Joe, USGS gaging station 12415140, St. Joe River near Chatcolet; Spokane River, USGS gaging station 12417598, Spokane River at Lake Outlet at Coeur d’Alene. Sampling location on the Coeur d’Alene River for both studies was at USGS gaging station 12413860, Coeur d’Alene River near Harrison. Loads and errors are in kilograms per year. Streamflows are in cubic hectometers per year. Abbreviations: ND, analyte concentration frequently less than method reporting limit; unable to calculate loads using LOADEST; USGS, U.S. Geological Survey ; NA, not applicable]
Variable | Budget component | Calendar year | Water year | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1991 | 1992 | 2004 | 2005 | 2006 | ||||||||
Load | Error | Load | Error | Load | Error | Load | Error | Load | Error | |||
Total cadmium | ||||||||||||
Gaged inflow | St. Joe River | ND | NA | ND | NA | ND | NA | ND | NA | ND | NA | |
Coeur d’Alene River | 8,930 | 1,070 | 4,170 | 460 | 2,300 | 270 | 3,090 | 420 | 3,300 | 440 | ||
Gaged outflow | Spokane River | 5,720 | 680 | 2,560 | 290 | 1,000 | 60 | 930 | 50 | 1,270 | 90 | |
Total lead | ||||||||||||
Gaged inflow | St. Joe River | 34,400 | 9,300 | 5,860 | 1,300 | 380 | 70 | 530 | 130 | 740 | 160 | |
Coeur d’Alene River | 488,000 | 111,000 | 74,400 | 11,000 | 85,400 | 13,600 | 111,000 | 22,100 | 178,000 | 32,800 | ||
Gaged outflow | Spokane River | 68,200 | 9,300 | 13,400 | 1,510 | 5,540 | 640 | 5,050 | 570 | 6,520 | 1,160 | |
Total zinc | ||||||||||||
Gaged inflow | St. Joe River | 59,900 | 18,000 | 39,300 | 11,000 | 2,870 | 500 | 3,830 | 760 | 5,190 | 840 | |
Coeur d’Alene River | 935,000 | 127,000 | 444,000 | 52,200 | 367,000 | 46,000 | 482,000 | 69,200 | 552,000 | 77,400 | ||
Gaged outflow | Spokane River | 648,000 | 50,800 | 324,000 | 23,100 | 240,000 | 7,630 | 235,000 | 8,060 | 309,000 | 12,900 | |
Summary | ||||||||||||
Constituent load | Calendar year | Water year | ||||||||||
1991 | 1992 | 2004 | 2005 | 2006 | ||||||||
Total cadmium | ||||||||||||
Total inflow | 8,930 | 4,170 | 2,300 | 3,090 | 3,300 | |||||||
Total outflow | 5,720 | 2,560 | 1,000 | 930 | 1,270 | |||||||
Residual (outflow-inflow) | -3,210 | -1,610 | -1,300 | -2,160 | -2,030 | |||||||
Residual (percentage of inflow) | 36 | 39 | 56 | 70 | 62 | |||||||
Overall error | 1,270 | 540 | 280 | 420 | 450 | |||||||
Total lead | ||||||||||||
Total inflow | 522,000 | 80,300 | 85,800 | 112,000 | 179,000 | |||||||
Total outflow | 68,200 | 13,400 | 5,540 | 5,050 | 6,520 | |||||||
Residual (outflow-inflow) | -454,000 | -66,900 | -80,300 | -107,000 | -172,000 | |||||||
Residual (percentage of inflow) | 87 | 83 | 94 | 95 | 96 | |||||||
Overall error | 112,000 | 11,200 | 13,600 | 22,100 | 32,800 | |||||||
Total zinc | ||||||||||||
Total inflow | 995,000 | 483,000 | 370,000 | 486,000 | 557,000 | |||||||
Total outflow | 648,000 | 324,000 | 240,000 | 235,000 | 309,000 | |||||||
Residual (outflow-inflow) | -347,000 | -159,000 | -130,000 | -251,000 | -248,000 | |||||||
Residual (percentage of inflow) | 35 | 33 | 35 | 52 | 44 | |||||||
Overall error | 138,000 | 58,100 | 46,600 | 69,700 | 78,500 |