Prepared in cooperation with the Wisconsin Department of Transportation and the Wisconsin Department of Natural Resources Highway-Runoff Quality, and Treatment Efficiencies of a Hydrodynamic-Settling Device and a Stormwater-Filtration Device in Milwaukee, Wisconsin Scientific Investigations Report 2010–5160 U.S. Department of the Interior U.S. Geological Survey Cover (clockwise from top left). View of eastbound I-794, view of westbound I-794, installation of the stormwater-filtration device, and installation of the hydrodynamic-settling device. Photographs by Robert Pearson, Wisconsin Department of Transportation. Highway-Runoff Quality, and Treatment Efficiencies of a Hydrodynamic-Settling Device and a Stormwater-Filtration Device in Milwaukee, Wisconsin By Judy A. Horwatich, Roger T. Bannerman, and Robert Pearson Prepared in cooperation with the Wisconsin Department of Transportation and the Wisconsin Department of Natural Resources Scientific Investigations Report 2010–5160 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2011 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Horwatich, J.A., Bannerman, R.T., and Pearson, Robert, 2010, Highway-Runoff Quality, and Treatment Efficiencies of a Hydrodynamic-Settling Device and a Stormwater-Filtration Device in Milwaukee, Wisconsin: U.S. Geological Survey Scientific Investigations Report 2010–5160, 75 p. iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Purpose and Scope .............................................................................................................................2 Site Description ....................................................................................................................................2 Hydrodynamic-Settling Device ..................................................................................................4 Stormwater-Filtration Device .....................................................................................................4 Description of the Hydrodynamic-Settling and Stormwater-Filtration Devices .................................4 Hydrodynamic-Settling Device ..................................................................................................5 Stormwater-Filtration Device .....................................................................................................5 Sampling Methods .........................................................................................................................................6 Measurement of Precipitation Depths .............................................................................................6 Calibration of Flow ................................................................................................................................6 Water-Quality Sampling .......................................................................................................................8 Particle-Size Analyses .........................................................................................................................9 Monitoring Complications ...................................................................................................................9 Quality Control .....................................................................................................................................11 Hydrodynamic-Settling Device ................................................................................................11 Stormwater-Filtration Device ...................................................................................................13 Evaluation of the Hydrodynamic-Settling and Stormwater-Filtration Devices ..................................13 Precipitation Data ...............................................................................................................................13 Number of Precipitation Events with Water-Quality Data ...........................................................14 Flow Data..............................................................................................................................................14 Particle-Size Distributions .................................................................................................................17 Hydrodynamic-Settling Device ................................................................................................17 Stormwater-Filtration Device ...................................................................................................19 Summary of Inlet and Outlet of Chemical Concentrations ...........................................................21 Efficiency Calculations ......................................................................................................................25 Efficiency Ratio....................................................................................................................................26 Hydrodynamic-Settling Device ................................................................................................26 Stormwater-Filtration Device ...................................................................................................28 Summation of Loads ...........................................................................................................................28 Hydrodynamic-Settling Device ................................................................................................30 Stormwater-Filtration Device ...................................................................................................30 Total Suspended-Solids Reductions in Other Field-Verification Studies of the Hydrodynamic-Settling and Stormwater-Filtration Devices ..........................................31 Hydrodynamic-Settling Device ................................................................................................31 Stormwater-Filtration Device ...................................................................................................32 Mass Balance of Sediment Retained in the Devices ...................................................................32 Hydrodynamic-Settling Device ................................................................................................33 Stormwater-Filtration Device ...................................................................................................33 Summary and Conclusions ........................................................................................................................37 Acknowledgments .......................................................................................................................................38 References Cited..........................................................................................................................................38 Appendix 1. Previous Studies .................................................................................................................41 Appendix 2. Hydrodynamic-Settling Device ........................................................................................44 Appendix 3. Stormwater-Filtration Device ...........................................................................................61 iv Figures 1. Aerial photographs showing location of monitored sites for the hydrodynamic- settling and stormwater-filtration devices in the City of Milwaukee, Wisconsin ..............3 2. Photograph showing piping system from the westbound I–794 freeway to the hydrodynamic-settling device ....................................................................................................4 3. Schematic diagram of the hydrodynamic-settling device .....................................................5 4. Schematic diagram of the stormwater-filtration device ........................................................6 5–8. Photographs showing— 5. Rain gage used for continuous measurement of precipitation ...................................7 6. Flow-calibration equipment ...............................................................................................8 7. Automatic water-quality sampling equipment ................................................................9 8. Piping modification for the hydrodynamic-settling device .........................................12 9–12. Graphs showing— 9. Cumulative precipitation distributions