Characterization and prediction of gross solids mass, organic matter, and total phosphorus in urban stormwater

Water Science & Technology · 2025-09-11

ABSTRACT Gross solid materials carried in stormwater runoff can obstruct stormwater systems and transport nutrients and other pollutants to waterways. To characterize key drivers of the mass of gross solid delivered to stormwater systems and the amount of total phosphorus (TP) contributed by these solids, we collected these materials from the inlets of 13 stormwater control measures (SCMs) located in the Minneapolis – St. Paul metropolitan region in Minnesota, USA. Samples were collected from sampler devices during the years 2021–2022. Dry mass and mass organic matter (OM) were measured for all 420 samples collected, and 35% of all samples were analyzed for TP. A regression equation was developed to estimate TP mass for all samples based on measured OM. Additional analysis was performed to determine statistically significant factors that predicted the mass of gross solid material collected at each SCM. Annual dry mass, mass OM, and mass TP of the gross solid materials ranged from 6.1 to 76.9, 1.9 to 45.4, and 0.004 to 0.119 kg yr−1, respectively. The tree canopy area over the street was the best predictor of the annual dry mass, OM mass, and TP mass delivered at the SCMs, with R2 values of 0.44, 0.47, and 0.5, respectively.

Understanding the Why—The Effects of Education on Stormwater Managers

2025-05-15

Worker understanding and buy-in is a crucial first step in achieving the goal of stormwater management acceptance. When those who install and manage stormwater practices are educated in understanding why these practices are needed and how to properly maintain them, workers are more likely to do what is necessary to ensure appropriate erosion prevention, sediment control, and stormwater management. Between 2009 and 2019, the University of Minnesota Erosion and Stormwater Management Program trained over 5,000 construction site managers about stormwater regulations, technologies, and techniques related to their roles. Attendees rated their perceived before- and after-class knowledge change as well as their anticipated behavioral changes due to the course. All six self-reported before- and after-course knowledge changes were statistically significant. Additionally, the six self-reported changes in before- and after-course anticipated behaviors were also statistically significant. These findings strongly suggest that education is an effective tool to advance the acceptance of stormwater management.

Settling velocities of coarse organic solids

Scientific Reports · 2023-08-01 · 1 citations

Abstract The settling velocity of a particle is an integral parameter in stormwater modeling and design. The settling velocity can be used to predict the fate and transport of stormwater particles and if the particles contribute to nutrient loading in a watershed. Prediction of settling velocity for inorganic particles is generally well-researched and well-understood. Organic particles tend to vary widely in their physical properties and there are currently no set standards or empirical equations for estimating the settling velocity of organic particles. This paper presents data from tree leaves and seeds settling velocity experiments to better understand how organic particles settle in the context of settling velocity equations such as the one developed by Ferguson and Church. Analysis of the collected data showed that the second of the two drag coefficients (C 2 ) used in the Ferguson and Church Equation was sensitive to particle type and shape. By averaging C 2 by particle type and species, there was a correlation between the observed settling velocity and the settling velocity predicted by the Ferguson and Church Equation (R 2 = 0.83). With these results, stormwater modelers and designers are equipped with a better understanding of how to represent common organic particles in terms of settling velocity. Additional research on a wider variety of organic particle types and species would expand on the dataset presented here.

Legumes are the key to increasing productivity at “Inverary”, a summer moist hill / high country farm in mid-Canterbury

Journal of New Zealand Grasslands · 2022 · 4 citations

• Agronomy
• Biology
• Geography

About half the 4250 ha of Inverary is undevelopedmountain land above 750 m a.s.l. There are 300 haof river flats, where lucerne and winter feed cropsare grown, and 300 ha conventional grass/cloverpastures. Limited areas of clover/plantain and winterfeed crops have been established at ~700 m a.s.l. oneasy rolling country. The 1600 ha of steep country,dominated by browntop, gives low spring and highsummer production that is difficult to manage. In2009, there were no lucerne or legume rich pastures.The legume emphasis increased animal productivitythrough improved lambing and lamb weight sold perewe. Total lamb meat production lifted from 230,113kg in 2009 to 245,039 kg in 2020, despite 1000 fewerewes. The current sheep to cattle ratio is 60:40 with13,000 stock units being wintered. Pre-development,a major shortage of nutritious forage in early springwas compounded by difficulty controlling reproductivegrass in summer and autumn. In 2016, total productionof legume dominant pastures was 40% more than sowngrass/clover pastures with limited nitrogen fertiliser(15 vs. 11 t DM/ha/year). In early spring, legumeshad higher growth rates of conventional grass/cloverpastures (90 vs. 44 kg DM/ha/day), whereas browntopdominant hill pastures grew 10 kg DM/ha/d and 5 tDM/ha/yr.

Stormwater Research Roadmap for Minnesota

University of Minnesota Digital Conservancy (University of Minnesota) · 2021-05-20 · 1 citations

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.

Three tips for creating an online course for nontraditional student populations

Ecology and Evolution · 2021 · 1 citations

• Computer Science
• Medical education
• Political Science

In spring 2020, the University of Minnesota Erosion and Stormwater Management Certification Program temporarily ceased in-person workshops due to the spread of COVID-19. Twenty workshops were canceled, and the 1,233 attendees (all adult learners) were moved into asynchronous online course sections. These online workshops were the first remote courses that many of the attendees had ever attempted. Here, we provide tips for successfully creating online classes for nontraditional student populations.

Methodology to Evaluate Performance of Sediment Control Log Filter Media

Journal of Irrigation and Drainage Engineering · 2021-11-03 · 1 citations

Stormwater management is necessary to protect surface waters from pollutants, and significant amounts of time and money are being expended to purchase and install sediment control logs for this purpose. Testing to compare new innovations in sediment control log filter media and uses has been done; however, more is needed. Whereas testing has traditionally been done using open-channel flumes, a large-scale constant head permeameter was used in this study, and its measurements were compared with testing results from open-channel flume measurements to indicate that this testing method is viable, if not a preferable, alternative. A nonlinear relationship involving the specific discharge was determined in a variety of filter media, including straw, coir, wood fiber, rock, and wood compost. The nonlinear relationship suggests that a nonlaminar flow is occurring within the media. The height of the seepage emerging from the downstream face of a sediment control log was also demonstrated to be a critical measured parameter if an open-channel flume is used as a testing apparatus. This study also included sediment capture testing and revealed that sediment control logs are capable of removing 72% to 92% of suspended sediments by weight, mostly through sedimentation, but with as much as 15% removal through filtration, depending on the media type.

Characterization of Stormwater Particle Size Distribution and Sediment Concentrations through Evaluation of Manhole Sumps with SHSAM

2020

• Environmental science
• Geography
• Engineering

Urban stormwater runoff contains sediment which pollutes water resources. Manhole sump structures
\nhave been constructed in many cities to capture the sediment material, but removal of the captured
\nsediment has to be done for this system to be effective. Software is available to estimate sediment
\nbuild up and help predict maintenance needs, but the software requires inputs of stormwater sediment
\nconcentration and stormwater sediment particle size distributions (PSDs). This study uses historical data
\nfrom the University of Minnesota Twin Cities Campus Water Utility and the City of St. Cloud Minnesota
\nmaintenance records to calibrate the SHSAM model for stormwater runoff parameters. Assessment of
\nthe maintenance activity has also been done to evaluate maintenance effectiveness.
\nSediments in urban stormwater can be characterized using a NURP50 PSD, which will provide a
\nconservative estimate if you are using PSD for removal efficiency since finer particles settle slower and
\nare less often removed by treatment. We recommend using a coarser PSD’s with a D50 of 0.05mm to
\n0.1mm if you are using a PSD for estimating maintenance schedules and sediment removal amounts.
\nWhen using the SHSAM model, the sediment concentration value appears to be more sensitive than the
\nPSD input parameter.
\nWe propose a sediment concentration of 400 mg/L be used for the SHSAM model or other calculations
\nas an average value, with a typical range of 250 mg/L to 450 mg/L. Variation occurs with watershed
\ncharacteristics and location and there is also variation in concentration with storm events.
\nInspecting sump structures once per year with maintenance following inspections appears to result in
\ncapture of half of the accumulated sediments, with approximately half of the sediments being lost from
\nflushing in intense storm events. Removal of the full sediment load captured appears possible if
\ncleanout activity occurs twice per year. There is 1.68 c.f. of sediment captured per drainage acre per
\nyear with annual inspections followed by maintenance, while 3.08 c.f. of sediment is generated per acre
\nper year. The sump material volume per acre of drainage is 5.32 c.f. when including organic material.
\nThe overall cost for stormwater sediment capture by sumps is approximately $600/CF.
\nUse of calibrated input parameters in calculations and models, such as those determined here result in
\nmore accurate estimates of maintenance needs. Analysis of maintenance records also provides insight
\ninto how effective the maintenance is and how it can be improved.

DSEF-UNCG Sales Leadership Module: Designed by Fellows - For Fellows

2020-01-01

Sediment Control Log Performance, Design, and Decision Matrix for Field Applications

University of Minnesota Digital Conservancy (University of Minnesota) · 2019-05-01

Significant time and money are currently being expended in the purchase and installation of sediment control logs. These logs often fail because of poorly understood performance limits and improper installation. This project investigated the performance limits by determining the flow and sediment removal characteristics of different types of logs. The physical characteristics and flow rates per project area were evaluated with twelve different logs. The densities and flow rate of materials in these logs varied between 0.035 gm/cm3 and 1508 ft /min for wood fiber to 0.269 gm/cm3 and 208 ft/min for compost. Flow rates were predicted using a power function of density with fair accuracy (r2=0.64) and predicted with good accuracy using saturated conductivity (r2=0.87) or capillary moisture content (r2=0.81). A sediment flume was constructed and used to evaluate sediment removal and failure rates. One log with three replicates of each type of material was tested. There was a positive, power function relationship between percent finer and mean log capture (r2 = 0.91). Field information was collected and used in conjunction with hydraulic and sediment data to develop selection guidelines for sediment control logs. Educational materials were prepared for workshops.