Constituent (concentrations reported in mg/L) | Wisconsin Data1 | Twin Cities Highways2 | ||||
---|---|---|---|---|---|---|
Arterial Street | Feeder Street | Collector Street | Collector Street | Residential Driveway | ||
Cadmium | 0.0028 | 0.0008 | 0.0017 | 0.0012 | 0.0005 | 0.0025 |
Chromium | 0.026 | 0.007 | 0.013 | 0.016 | 0.002 | |
Copper | 0.085 | 0.025 | 0.061 | 0.047 | 0.02 | 0.023 |
Lead | 0.085 | 0.038 | 0.062 | 0.062 | 0.02 | 0.242 |
Zinc | 0.629 | 0.245 | 0.357 | 0.361 | 0.113 | 0.123 |
Nitrate-Nitrite | 0.77 | |||||
Total Phosphorus | 1.01 | 1.77 | 1.22 | 0.48 | 1.5 | 0.43 |
Total Dissolved Phosphorus | 0.62 | 0.55 | 0.36 | 0.07 | 0.87 | |
Chloride3 | 11.5 | |||||
Total Suspended Solids | 993 | 1152 | 544 | 603 | 328 | |
Suspended Solids | 875 | 1085 | 386 | 474 | 193 |
1 Arithmetic mean concentration; Reference: Roger T. Bannerman and Richard Dodds, Sources of Pollutants in Wisconsin Stormwater, 1992
2 Reference: University of Minnesota Water Resources Center, Assessment of Stormwater Best Management Practices Manual, 2008
3 Data represents chloride concentrations during monitoring season, typically April through October. Chloride concentrations in winter snowmelt grab samples have been found to be as great as 3,600 mg/L.