Digital Commons Network^™

Multiscale Assessment Of Drinking Water Treatment Residuals As A Phosphorus Sorbing Amendment In Stormwater Bioretention Systems, Michael Rick Ament

Graduate College Dissertations and Theses

Bioretention systems can reduce stormwater runoff volumes and filter pollutants. However, bioretention soil media can have limited capacity to retain phosphorus (P), and can even be a P source, necessitating P-sorbing amendments. Drinking water treatment residuals (DWTRs) have promise as a bioretention media amendment due to their high P sorption capacity. This research explores the potential for DWTRs to mitigate urban P loads using a combination of lab experiments, field trials, and an urban watershed model.

In the laboratory portion of this research, I investigated possible tradeoffs between P retention and hydraulic conductivity in DWTRs to inform bioretention media designs. …

Evaluation Of Nitrogen And Phosphorus Removal In Alternative Management Practices For Dairy Farm Production Area Runoff: Bioretention Cells And A Woodchip Bioreactor Treatment System, Jillian Sarazen

Graduate College Dissertations and Theses

Non-point source pollution from agricultural areas can lead to the degradation of downstream water bodies, including eutrophication and harmful algal blooms, due to high concentrations of nitrogen (N) and phosphorus (P) emanating from these areas. One source of agricultural runoff that is often overlooked, originates from agricultural production areas, which have impervious surfaces, such as paved and compacted areas, barnyards, cow paths, and silage bunker storage; these areas generate stormwater runoff and contribute to pollution during storm events.

This research evaluates two built stormwater runoff treatment systems designed to treat high concentrations of nutrients in runoff from a dairy farm. …

Effects Of Different Soil Media, Vegetation, And Hydrologic Treatments On Nutrient And Sediment Removal In Roadside Bioretention Systems, Paliza Shrestha, Stephanie E. Hurley, Beverley C. Wemple

College of Agriculture and Life Sciences Faculty Publications

Water quality performance of eight roadside bioretention cells in their third and fourth years of implementation were evaluated in Burlington, Vermont. Bioretention cells received varying treatments: (1) vegetation with high-diversity (7 species) and low-diversity plant mix (2 species); (2) proprietary SorbtiveMedia™ (SM) containing iron and aluminum oxide granules to enhance sorption capacity for phosphorus; and (3) enhanced rainfall and runoff (RR) to certain cells (including one with SM treatment) at three levels (15%, 20%, 60% more than their control counterparts), mimicking anticipated precipitation increases associated with climate change. A total of 121 storms across all cells were evaluated in 2015 …

Soil Media Co2 And N2O Fluxes Dynamics From Sand-Based Roadside Bioretention Systems, Paliza Shrestha, Stephanie E. Hurley, E. Carol Adair

College of Agriculture and Life Sciences Faculty Publications

Green stormwater infrastructure such as bioretention is commonly implemented in urban areas for stormwater quality improvements. Although bioretention systems' soil media and vegetation have the potential to increase carbon (C) and nitrogen (N) storage for climate change mitigation, this storage potential has not been rigorously studied, and any analysis of it must consider the question of whether bioretention emits greenhouse gases to the atmosphere. We monitored eight roadside bioretention cells for CO2-C and N2O-N fluxes during two growing seasons (May through October) in Vermont, USA. C and N stocks in the soil media layers, microbes, and aboveground vegetation were also …

Water Quality Performance And Greenhouse Gas Flux Dynamics From Compost-Amended Bioretention Systems & Potential Trade-Offs Between Phytoremediation And Water Quality Stemming From Compost Amendments, Paliza Shrestha

Graduate College Dissertations and Theses

Stormwater runoff from existing impervious surfaces needs to be managed to protect downstream waterbodies from hydrologic and water quality impacts associated with development. As urban expansion continues at a rapid pace, increasing impervious cover, and climate change yields more frequent extreme precipitation events, increasing the need for improved stormwater management. Although green infrastructure such as bioretention has been implemented in urban areas for stormwater quality improvements and volume reductions, these systems are seldom monitored to validate their performance. Herein, we evaluate flow attenuation, stormwater quality performance, and nutrient cycling from eight roadside bioretention cells in their third and fourth years …

Bioretention In A Mixed-Use Agricultural Landscape: Lessons Learned From The Application Of Low-Phosphorus Compost And Panicum Virgatum, Jason M. Kokkinos

Graduate College Dissertations and Theses

Bioretention cells are a stormwater treatment technology that uses soil and vegetation to remove pollutants from runoff and improve downstream water quality. While bioretention has been shown to be effective at removing certain stormwater pollutants such as sediment and heavy metals, removal of nutrients has been more variable. Design components of bioretention such as vegetation and soil media amendments can influence pollutant removal performance. In my experiment, I isolate the effects of low-phosphorus compost and a Switchgrass (Panicum virgatum) monoculture on bioretention performance. In fall 2016, three bioretention cells were installed at the University of Vermont Miller Research Complex, a …

Evaluating Stormwater Pollutant Removal Mechanisms By Bioretention In The Context Of Climate Change, Amanda Cording

Graduate College Dissertations and Theses

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or …