October 14th Stormwater Seminars
Title: What can learn from stormwater manhole sumps?
Presented by: John Chapman, Ph.D., P.E., Assistant Research Professor and Program Director, Erosion and Stormwater Management Certification Program, University of Minnesota - Bioproducts and Biosystems Engineering Department
Characterization of Stormwater Particle Size Distribution and Sediment Concentration through Evaluation of Manhole Sumps with SHSAM
The stormwater manhole sump. A simple concept, where you extend the manhole below the outlet pipe to create a sedimentation pool. Manhole sumps have been installed for decades, but what can we learn if we look closely at what gets collected? Using historical data and modeling software originally developed to look at hydrodynamic separators we have gained insight to the stormwater sediment concentrations and particle distributions. In the process, we have also learned some lessons on clean out frequency. This presentation will feature the results a recently completed research project.
John Chapman is an Assistant Research Professor for the University of Minnesota Department of Bioproducts and Biosystems Engineering and also serves as the Director of the Erosion and Stormwater Management Certification Program. John holds a Ph.D. in Civil Engineering and is a registered engineer in Minnesota and Colorado. When not researching erosion control and stormwater, he conducts workshops for engineers, contractors and other professionals on stormwater management technology and regulations.
Title: Developing a street sweeping credit for stormwater phosphorus source reduction
Presented by: Sarah Hobbie and Mike Trojan
Excess phosphorus (P) loading of urban surface waters continues to contribute to their impairment. Because of the importance of tree litterfall in contributing P to stormwater, street sweeping is a promising management tool for reducing P loading of surface waters in urban and suburban regions, especially where tree canopy cover is high. However, widespread adoption of frequent street sweeping as a management tool has been hindered by lack of a pollution credit for P removal through street sweeping. We aimed to develop empirical predictive models of the concentrations and total amounts of P (and nitrogen and solids) collected in city street sweeping efforts, to inform the development of a stormwater phosphorus (P) crediting program for street sweeping by the Minnesota Pollution Control Agency. Towards that end, we collected street sweepings during routine street sweeping operations in five cities in the Minneapolis-St. Paul Metropolitan Area – Forest Lake, Minneapolis, Prior Lake, Roseville, and Shoreview – and analyzed them for mass, P, nitrogen, carbon, and moisture content. We evaluated different statistical approaches for estimating P recovered in street sweepings, towards directly informing the development of a street sweeping P credit. This presentation will feature the results of this work finishing the fall of 2020.
Sarah Hobbie is a Distinguished McKnight University Professor in the Department of Ecology, Evolution and Behavior. Her research focuses on the influence of changes in atmospheric composition, climate, and land use on communities and ecosystems, and on the effects of urbanization on biodiversity and water quality. Dr. Hobbie currently serves as co-leader of the Cedar Creek Long Term Ecological Research program. She is a member of the National Academy of Sciences and an American Academy of Arts and Sciences Fellow. Nationally, she serves on the Advisory Board of the Earth Leadership Program and on several editorial boards.
Mike Trojan (not pictured) is Hydrologist with the Stormwater Program at the Minnesota Pollution Control Agency and leads work on the Minnesota Stormwater Manual and is a co-investigator on this project.