Browsing by Subject "Infiltration"

Now showing 1 - 11 of 11
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    Analysis of Infiltration and Overland Flow over Sloped Surfaces: Application to Roadside Swales
    (2017-06) Garcia de la Serrana Lozano, Maria Del Carmen
    Environmental impacts and regulatory requirements associated with highway runoff present design challenges. Roadside swales, or drainage ditches, improve water quality by infiltration, filtration, and sedimentation. Road runoff volume reduction through infiltration occurs as the water flows over the side slope, acting as a filter strip, or down the length of the swale channel. Therefore, roadside swales are practical solutions that can mitigate the effect that linear transportation projects have on water bodies. This dissertation advances the understanding of the infiltration performance of roadside swales for design and planning purposes. The main objectives of this thesis are: understanding the overland flow and infiltration processes over a fraction of a slope, relating surface roughness parameters to the fraction of wetted area, and quantifying the effect of equidistant parallel strip water sources on the lateral component of infiltration. Moreover, this research leads to a better understanding of overland flow and infiltration in roadside swales through field experiments, and modeling efforts that can simulate how roadside swales operate. All the field tests, performed in four different highways, showed that water flow on the side slope of a roadside swale is concentrated in fingers, instead of sheet flow, at the typical road runoff intensities for which infiltration practices are utilized to improve surface water quality. The laboratory experiments aimed to formulate the relevance of fractal parameters, based on the Fourier power spectrum method, for understanding soil surface roughness, overland flow patterns, and erosion. A model has been developed for coupling a Green-Ampt-Mein-Larson infiltration submodel with kinematic wave submodels for both overland flow down the side slope and open channel flow for flow in the channel. The side slope of a roadside swale is the main part contributing to the loss of runoff by infiltration and the channel primarily conveys the water. Finally, a simplified roadside swale calculator has been developed with a reduced set of input parameters. The calculator can estimate the total percentage of annual volume infiltrated, supporting informed decision-making on how to account for the infiltration benefits of roadside swales.
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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.
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    Characterizing the performance of a new iniltrometer and hydraulic properties of roadside swales
    (2014-09) Ahmed, Farzana
    A roadside swale is an infiltration practice that removes water during rainfall-runoff, infiltrate water into the soil and filter the soil and associate pollutant from the water. Infiltration rate is an important factor affecting the performance of a swale. Though roadside swales convey and treat road runoff, data on the performance of swales with regards to infiltration is relatively sparse. Therefore, the objective of this study is to, 1) Modify the optimization technique of the new Modified Philip Dunne (MPD) infiltrometer, 2) Verify the results obtained from this MPD infiltrometer for uniform soil, layered soil and uniform soil with macopores by numerical simulation, 3) Utilize the MPD infiltrometer to characterize the field-saturated hydraulic conductivity (Kfs) of five roadside swales located in Twin-Cities, MN and one swale located in Madison, WI and 4) Analyze the derived results obtained from the measurements taken by the MPD infiltrometer. From numerical simulations it was found that MPD Infiltrometer overestimates Kfs value by 10 to 36% for the uniform soil, 12% to 63% for layered soil and 4% to 29% for uniform soil containing macropores. MPD infiltrometer allows collecting multiple infiltration measurements simultaneously to capture the spatial variation of infiltration rate of an infiltration practice. In this study a total of 720 infiltration measurements were collected in swales located in Twin-Cities, MN and in Madison, WI. Statistical analysis was performed on the Kfs values to analyze the effect of initial soil moisture content, season, soil texture class and distance in downstream direction on the geometric mean Kfs value of a swale. Because of high spatial variation of Kfs value in the same swale no effect of initial soil moisture content, season and soil texture class was observed on the geometric mean Kfs value. But the distance in downstream direction may have positive or negative effect on the Kfs value.
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    Continued Monitoring of Stormwater Effluents from Filter Media in Two Bioslope Sites
    (Minnesota Department of Transportation, 2021-06) Cai, Meijun; Patelke, Marsha; Saftner, David
    Over the last thirty years, the Minnesota Department of Transportation (MnDOT) has implemented biofilters along roadways as a stormwater control measure. The state and national regulations require that the biofilters must be able to infiltrate and treat the first inch of rainfall onsite. However, the performance of the biofilters after installation has rarely been studied. An early phase of this project monitored two newly constructed biofilter sites for two years and for three months, respectively. This study extended the monitoring of soil moisture changes and infiltration water quality for another two years (2019-2020). Over the four-year monitoring period, both salvage peat and compost materials showed the capacity to retain the first inch of runoff, and this retention capacity did not change over the study period. The drainage water quality showed significantly temporal trends, particularly phosphorus concentrations, which were declining significantly for both compost and salvage peat. The application of tailing with compost can reduce the phosphorus release. The leachate from salvage peat has similar metal concentrations but much lower phosphorus concentrations (below 100 ppb) than the compost. The lowest chemical concentrations were achieved when the soil mixture contained 10% compost and 10% salvage peat, implying the best stormwater control practice is to limit the organic ratio to around 20%. Findings from this work determined the validity of using peat and compost for future biofilters and can aid in future design.
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    Design and Construction of Infiltration Facilities
    (Minnesota Department of Transportation, 2021-06) Tecca, Nicholas P.; Gulliver, John S.; Nieber, John L.; Weiss, Peter T.
    Infiltration stormwater control measures are an important structural practice to mitigate the impacts of urbanization on stormwater quality and quantity. Infiltration stormwater control measures help to mimic the natural processes of infiltration and evapotranspiration. Unfortunately, the failure rate of infiltration stormwater control measures has been observed to be between 10% and 50%. Two common causes of failure are addressed in this work, namely improper siting and improper characterization of saturated hydraulic conductivity. A procedure to calculate a preliminary infiltration rating (PIR) was developed in a geographic information system to identify areas where infiltration stormwater control measures are likely to be successful. The Modified Philip-Dunne infiltrometer, double ring infiltrometer, Turf-Tec IN2-W infiltrometer, and soil texture analysis were used to estimate infiltration capacity in three swales in the Twin Cities Metropolitan area. A correction factor was proposed for the Turf-Tec IN2-W infiltrometer. A protocol for assessing infiltration capacity was also proposed.
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    Development and Regionalization of In Situ Bioslopes and Bioswales
    (Minnesota Department of Transportation, 2019-07) Johnson, Kurt W.; Cai, Meijun; Patelke, Marsha; Saftner, David; Cruz, Chanelle
    This project is a multi-disciplinary investigation into the use of alternative media for biofiltration systems in Minnesota. Over the last thirty years, the Minnesota Department of Transportation (MnDOT) has implemented biofilters along roadways as a stormwater control measure. These systems must be able to infiltrate and treat the first inch of rainfall onsite to meet state and national regulations. The performance of a biofilter is largely based on its media?s ability to infiltrate water, sustain vegetation, and capture pollutants. To date, MnDOT has relied on sand and compost mixtures for biofilter media components. An early phase of this work identified peat as having similar performance characteristics as compost, making it an ideal alternative. A laboratory testing program was also developed during the early phase of work to determine media properties that could be used to predict biofilter performance. This project focused on characterizing existing biofilters using in situ testing and comparing results to laboratory testing. The comparison of the two methods demonstrated the predictive capabilities of the laboratory regime. This project also included the instrumentation and monitoring of field sites including a newly constructed peat amended biofilter. Findings from this work determined the validity of using peat for future biofilters and can aid in identifying and characterizing other alternative media.
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    Permeable Pavements in Cold Climates: State of the Art and Cold Climate Case Studies
    (Center for Transportation Studies, University of Minnesota, 2015-06) Weiss, Peter T.; Kayhanian, Masoud; Khazanovich, Lev; Gulliver, John S.
    This document is an extensive review of full-depth permeable pavements including porous asphalt, pervious concrete, and permeable interlocking concrete pavers (PICP). Also included is a brief section on articulated concrete blocks/mats. The main topics, which have been divided into chapters, include structural and mix design, hydrologic design, hydraulic performance (i.e. infiltration capacity), maintenance needs/frequency/actions, the impact of permeable pavement on water quality, results of a highway shoulder feasibility study, knowledge gaps, and several cold climate case studies from the United States and Canada. While progress has recently been made with the relatively new permeable pavement technology, researchers have also identified many unresolved issues that are not well understood. These include a methodology to measure subgrade infiltration rates, filling data gaps related to structural integrity, construction, and related issues associated with permeable pavements, determining what maintenance activities are most effective on various pavement types and how frequently specific maintenance actions should be performed, a better understanding of the processes involved in the observed reduction of contaminant concentrations in stormwater flowing through permeable pavements, and a better understanding of the performance of permeable pavements over a time frame that better corresponds with a life-span of 20 years.
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    Quantifying the effectiveness of soil remediation techniques in compact urban soils.
    (2010-12) Olson, Nicholas Charles
    Soils in urban environments typically have lower stormwater infiltration rates than the soils they replace due to reduced topsoil depth and increased subsoil compaction from land development. Loss of infiltration leads to increased stormwater runoff and associated downstream problems: flooding, pollutant transport, and warming stream temperatures. A field experiment was conducted to determine the effectiveness of remediation techniques to alleviate soil compaction and increase infiltration. Deep tillage and compost addition are two techniques commonly used in agricultural practices to reduce the level soil compaction. These techniques were implemented on three sites in the metropolitan area. Each site was divided into three plots: tilled, tilled with compost addition, and a control plot for comparison. To determine the effectiveness of each remediation technique, before and after measurements of saturated hydraulic conductivity (Ksat), soil bulk density, and soil strength were used to assess the level of compaction. Deep tillage was effective at reducing the level of soil strength. Soil strength was approximately half that of the control plot in the first six inches of soil. However, tilling did not significantly improve the bulk density of the soil. At two of the sites, tilling was ineffective at improving that infiltration capacity of the soil. Tilling may have damaged natural pathways in the soils, thus reducing the permeability. Tilling was effective at remediating the soil at one site, which was not as well-established at the previous two sites. The geometric mean of Ksat was 2.1 to 2.3 times that of the control plot Compost addition was the most effective soil remediation technique. Similar reductions in soil strength were found as the till plot. Soil bulk densities on the compost plots were 18-37% lower than the control plot. The infiltration capacity of the soil was improved. The geometric mean of Ksat on the compost plots was 2.7 to 5.7 times that of the control plot. The results of these findings will be useful in revising stormwater best management practices to include guidelines on soil compaction prevention and remediation of compacted sites.
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    Re-use of Regional Waste in Sustainably Designed Soils
    (Minnesota Department of Transportation, 2022-04) Saftner, David; Cai, Meijun; Whitcomb, Adam
    This project explores the potential re-use of waste materials/by-products as a soil amendment in northeastern Minnesota. The project team identified 23 waste/by-products and collected 15 of but only analyzed 11 because of the possible content of persistent chemicals in some of the materials or the unwillingness of the owner to participate. Peat screenings, peat scrapings, tree bark, harbor dredge sediment, coarse and fine taconite tailings, and street sweepings were characterized in physical, chemical, and biological properties through lab tests. The results showed that none of the studied materials were defined as hazardous based on RCRA (Resource Recovery and Conservation Act) metal levels and contained minimal or undetectable Polychlorinated biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs) or Volatile Organic Compounds (VOCs). Peat by-products were efficient in removing metals from stormwater runoff. The relatively high phosphorus content of peat by-products provided sufficient nutrients to plant growth but could be released when mixed with low-phosphorus runoff. Dredge sediment and street sweeping had low organic contents but could remove 90% or more of the copper from the runoff. Tailings could remove 50% or less of the metals. Radish or oat can successfully grow in 28 days with individual materials or a blend of materials, except for fine tailings, which are in a clay form and thus don't filter water well.
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    Stormwater BMP Inspection and Maintenance Resource Guide
    (Minnesota Department of Transportation, 2024-06) Erickson, Andrew J.; Gulliver, John S.; Weiss, Peter T.
    Stormwater treatment practices, often referred to as stormwater best management practices (BMPs), require a substantial commitment to maintenance, including regular inspections and assessments. Existing regulations require governmental units to develop a systematic approach for ongoing inspection and maintenance to ensure that they are achieving their desired treatment goals. A lack of maintenance will lead to a decrease in BMP performance and will often result in expensive rehabilitation or rebuild. In 2009, SRF Consulting produced a maintenance guide for the Local Road Research Board (LRRB) (Marti, et al. 2009). In 2023, the LRRB commissioned the University of Minnesota St. Anthony Falls Laboratory to update this guide to reflect new best practices. The Stormwater BMP Inspection and Maintenance Resource Guide (the Guide) is a supplement to the Minnesota Stormwater Manual (MPCA 2023) and will help the reader plan for recommended long-term maintenance activities through guidance on visual inspection, testing, and monitoring methods for identifying what maintenance is needed, and when it is needed. The Guide describes inspection and maintenance for constructed stormwater ponds (both dry and wet) and wetlands, underground sedimentation practices, infiltration practices, filtration practices, bioretention practices, permeable pavements, and stormwater harvesting. In addition, the Guide includes a section on Meeting Stormwater Management Objectives, which provides information on achieving reductions for sediment, phosphorus, nitrogen, metals, chloride, pathogens, and organic chemicals. The Guide also includes Field Inspections Resources, which contains inspection checklists and maintenance activity recommendations for all of the practices listed above.
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    Utilizing Waste Material From Minnesota For Stormwater Management Purposes
    (2024-05) Amoateng, Godbless
    Minnesota's mineral, forestry, agriculture, and industrial activities generate substantial by-products and waste. Strategies to reuse or recycle these can reduce landfill waste, enhance public health, conserve resources, and cut costs and emissions. Building on the frameworks by Johnson et al. (2017), Saftner et al. (2019), and Saftner et al. (2022), this project extended its scope across Minnesota to include materials like dredge sediment from Mississippi River, RCA (recycled concrete aggregate) and VersaLime. Researchers identified, selected, and characterized various waste, by-products, and commercial materials statewide and tested engineered soil mixes for roadway foundations, assessing their stormwater retention and support for native plants. Laboratory methods characterized these mixes, which were implemented and evaluated in situ. A preliminary environmental life cycle assessment was also conducted, quantifying the environmental impacts of the engineered soil mixtures. Results were compiled into a design guide for the Minnesota Department of Transportation (MnDOT) engineers.