Stormwater and Wastewater

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    Investigation of Coarse Organic Matter and Gross Solids Loading in Minnesota Urban Stormwater
    (2024-02) Chapman, John, A; Baker, Lawrence, M.; Finlay, Jacques, C.; Wilson, Grace, L.; Pietsch, Aaron, J.; Hoffman, Kathryn
    This study collected the gross solids, or largest particles in stormwater, using several different methods then characterized the nutrient content, settling velocity, and particle sizes of the material collected. This work can be summarized in four main components: Full Storm Capture; Settling Velocity; Annual Loadings; and P8 Modeling. The Full Storm Capture investigated different methods of storm runoff collection to better understand how collection methods may bias the amounts of the gross solids collected. The most reliable method was found to be with the use of 55-gallon barrels with modified lids that can be plumbed together and attached to a watershed outflow location. The first barrel in the series was fitted with an internal filter bag to capture most solids with additional barrels to collect flow. The last barrel lid includes a discharge weir that is monitored in cases where the storm event exceeds the barrel capacity. Use of other methods, such as automated samplers, sumps, regional collection facilities, all created some bias in the solids collected. The full storm capture method results in as much as 11 times more solids mass than other techniques. Settling Velocity investigated how large organic matter with internal air voids will saturate and settle in flow. Saturation of the voids occurred in 3 to 5 days resulting in specific gravity values just over 1.0 allowing particles to settle. The settling rates were measured and new coefficients were determined to model settling using the Ferguson and Church settling equation. The Annual Loading investigated how the gross solids are generated in urban watersheds and relates the accumulation to the watershed parameter of canopy area over pavement. The amount of phosphorous in the material was also related to the organic content. The organic content of the gross solids varied seasonally but did show strong relationship with the Normalized Difference Vegetation Index (NDVI) or “greenness” of the satellite imagery. The P8 Modeling effort created new particle files for the P8 software using the accumulation rates and settling velocities determined in the prior sections. This allows a P8 model to estimate the gross solids generated in an urban watershed and model removal with control measures such as ponds, sumps, or biofiltration systems. The P8 Model does not have a mechanism to calculate biomass generation, which limits the accuracy of the prediction of gross solids from vegetation.
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    2023 Annual Highlights of the Minnesota Stormwater Research Program and Minnesota Stormwater Research Council
    (2023-07-12) Billotta, John
    2023 Highlights of the Minnesota Stormwater Research Program
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    Final report and simulation program for "Monitoring Methods for Prioritization and Assessment of Stormwater Practices"
    (2022) Furuta, Daniel; Wilson, Bruce; Chapman, John; University of Minnesota Department of Bioproducts and Biosystems Engineering
    This project developed a framework for simulating stormwater sampling and for evaluating the performance of monitoring methods for runoff pollution. This submission contains the final report and a self-contained program practitioners can use to compare sampling methods, along with source code for the simulation program.
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    Pollutant Removal and Maintenance Assessment of Underground Sand Filters
    (2021) Shoemaker, Todd; Stone, Ali; Zhang, Lu; Fesenmaier, Mark; Stantec; Water Resources Center
    The purpose of this study is to evaluate the stormwater management effectiveness of installed underground sand filters in the Twin Cities Metro Area. The Minnesota Stormwater Manual includes guidance for the design and pollutant removal efficiency of surface and one type of underground sand filters. The most popular variety of underground sand filter, however, does not offer clear access to the sand media layer and is not included in the Minnesota Stormwater Manual. Maintenance is extremely limited by this design, which calls into question whether they can actually achieve the same removal efficiency as their aboveground couterparts, and whether those efficiencies degrade over time. There is limited data regarding performance of in-situ underground sand filters to assist in this evaluation. Some underground systems in the Metro have been installed for a decade, but their long-term performance has not been evaluated. Award of this grant would provide funding to investigate underground filtration performance. Study results will inform maintenance needs, judge longevity of these systems, provide design recommendations to design engineers, or if found to be an inadequate stormwater BMP, offer regulatory recommendations to watershed managers. Are there other PIs working with you?
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    Characterization of Stormwater Particle Size Distribution and Sediment Concentrations through Evaluation of Manhole Sumps with SHSAM
    (2020-03) Chapman, John A; Forman, M. Rebecca
    Urban stormwater runoff contains sediment which pollutes water resources. Manhole sump structures have been constructed in many cities to capture the sediment material, but removal of the captured sediment has to be done for this system to be effective. Software is available to estimate sediment build up and help predict maintenance needs, but the software requires inputs of stormwater sediment concentration and stormwater sediment particle size distributions (PSDs). This study uses historical data from the University of Minnesota Twin Cities Campus Water Utility and the City of St. Cloud Minnesota maintenance records to calibrate the SHSAM model for stormwater runoff parameters. Assessment of the maintenance activity has also been done to evaluate maintenance effectiveness. Sediments in urban stormwater can be characterized using a NURP50 PSD, which will provide a conservative estimate if you are using PSD for removal efficiency since finer particles settle slower and are less often removed by treatment. We recommend using a coarser PSD’s with a D50 of 0.05mm to 0.1mm if you are using a PSD for estimating maintenance schedules and sediment removal amounts. When using the SHSAM model, the sediment concentration value appears to be more sensitive than the PSD input parameter. We propose a sediment concentration of 400 mg/L be used for the SHSAM model or other calculations as an average value, with a typical range of 250 mg/L to 450 mg/L. Variation occurs with watershed characteristics and location and there is also variation in concentration with storm events. Inspecting sump structures once per year with maintenance following inspections appears to result in capture of half of the accumulated sediments, with approximately half of the sediments being lost from flushing in intense storm events. Removal of the full sediment load captured appears possible if cleanout activity occurs twice per year. There is 1.68 c.f. of sediment captured per drainage acre per year with annual inspections followed by maintenance, while 3.08 c.f. of sediment is generated per acre per year. The sump material volume per acre of drainage is 5.32 c.f. when including organic material. The overall cost for stormwater sediment capture by sumps is approximately $600/CF. Use of calibrated input parameters in calculations and models, such as those determined here result in more accurate estimates of maintenance needs. Analysis of maintenance records also provides insight into how effective the maintenance is and how it can be improved.
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    Stormwater Research Roadmap for Minnesota
    Bilotta, John P.; Chapman, John; Baker, Lawrence; Missaghi, Shahram; Fairbairn, David; jbilotta@umn.edu; Bilotta, John; Water Resources Center; Department of Bioproducts and Bioengineering; Minnesota Pollution Control Agency; Minnesota Extension; Minnesota Sea Grant
    The goal of the Stormwater Research Roadmap is to articulate major research needs to improve stormwater management in Minnesota. Multiple sources and approaches were used to identify stormwater research needs for Minnesota, including a review of relevant stormwater-related documents, and state-wide survey of stormwater managers, focus groups, and policy actor interviews. The Stormwater Research Roadmap for Minnesota identifies eight major areas that need additional research to improve stormwater management for communities, professionals, and agencies. Specific examples are included for each. Research in these areas can lead to more innovative management techniques and increased effectiveness and efficiency to prevent, minimize, and mitigate the effects of runoff from the built environment. The Roadmap also presents criteria to rank research needs. Data for the Roadmap was collected from 2017-2018 and was published in 2018.
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    Developing a Street Sweeping Credit for Stormwater Phosphorus Source Reduction: Final Report
    (2020-09) Hobbie, Sarah E.; King, Rachel; Belo, Tessa; Baker, Lawrence A.; Finlay, Jacques C.
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    Formation pathways for iron oxide minerals and geochemical conditions for phosphate retention in iron enhanced sand filters
    (UMN Water Resources Center, 2019-11-25) Fisher, Beth A.; Feinberg, Joshua M.
    Our overall goal for this project was to better understand the geochemical and mineralogical processes within Iron Enhanced Sand Filters (IESFs) that lead to effective removal of phosphorus. Our specific objectives were to (1) identify the most effective iron minerals for phosphorus trapping, (2) provide a screening method to optimize the success of Iron Enhanced Sand Filters (IESFs) to trap iron, (3) determine if iron minerals within filters get used up or remain active over time, and (4) use real time monitoring to understand IESF chemical conditions and dynamics. We thus structured our research activities and findings around answering these four questions: 1. What are the most effective minerals for phosphorus trapping? 2. Is there a method to screen iron sources prior to acquisition? 3. Do the iron minerals in the filter get used up over time? 4. Monitoring: Is the water and filter chemistry conducive for effective iron- phosphorus bonding?
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    Assessment of Stormwater Best Management Practices
    (University of Minnesota, 2008-04) Anderson, James L.; Asleson, Brooke C.; Baker, Lawrence A.; Erickson, Andrew J.; Gulliver, John S.; Hozalski, Raymond M.; Mohseni, Omid; Nieber, John L.; Riter, Trent; Weiss, Peter; Wilson, Bruce N.; Wilson, Matt A.; Gulliver, John S.; Anderson, James L.