Browsing by Author "Patelke, Marsha"

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    Comparing Properties of Water Absorbing/Filtering Media for Bioslope/Bioswale Design
    (Minnesota Department of Transportation, 2017-11) Johnson, Kurt; Cai, Meijun; Patelke, Marsha; Saftner, David; Swanson, Josh
    Drainage from highways, particularly the first flush of runoff, contains high levels of contaminants such as suspended solids, metals, and organics. To restrict the discharge of polluted stormwater, the National Pollutant Discharge Elimination System (NPDES) State Disposal System (SDS) General Permit issued by Minnesota Pollution Control Agency (MPCA) in 2013 requires that the first inch of stormwater runoff from new impervious should be held on site through infiltration, harvesting or reuse. Multiple types of infiltration materials have been studied in the laboratory and the field, but few studies have considered the application of local materials for best management practices (BMP). The objective of this project is to determine the characteristics of various naturally occurring water adsorbing and filtering media, such as peat and muck, found along road construction projects in northern Minnesota. Salvage and reuse of these materials during road construction will be evaluated for stormwater treatment, including absorption, infiltration, filtration, and pollutant capture, in constructed vegetated slopes along highway right of ways. The naturally occurring material will be compared to leaf and grass feedstock compost.
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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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    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.