The use of best management practices has become common in recent years, leading to the need for hydrologic models to predict their behavior and effectiveness. A vegetated filter strip at Mississippi State University was used to test two models: the Hydrologic Simulation Program-FORTRAN Best Management Practices Editor (HSPF BMPrac) and the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN). Water samples were taken during the Spring of 2011 and tested for sediments and nutrients; HSPF was used for computing flows, sediments, and nutrients. The filter strip was not effective at pollutant removal with removal efficiency rates of 68.1, 91.7, 86.3, and 115.4 percent for total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and dissolved phosphorus (DP) respectively. Calibration of HSPF was successful for TSS with a R2 value of 0.52; nutrients were not as successful with R2 values of 0.11 and 0.43 for TN and TP.

Excessive phosphorus (P) in runoff contributes to eutrophication of fresh water bodies. Studies have shown that manure and effluent applied from animal feeding operations to waste application fields (WAFs) have contributed to excess P in segments of the North Bosque River in east central Texas. There is a growing need for environmentally sound, economically viable, and easy to establish best management practices to control such pollution. Vegetative buffer strips offer a potential solution for reducing runoff P from WAFs by extracting it from soil and by reducing sediment P delivery (due to reduced runoff and soil erosion) to streams. In a field study, ten plots (5m x 5m) were assigned to five replicated treatments, namely control (bare, without having any plant cover), cool season grass, warm season forb, warm season grass, and warm season legume to assess their efficacy of runoff sediment control and P sequestration potential from soil. These plots were established on a coastal Bermuda grass WAF that received dairy lagoon effluent. A runoff collection system, a 1m x 1m sub-plot with a runoff conveyance and collection apparatus, was installed on the upstream and downstream margins of each plot. Natural rainfall runoff samples were collected and analyzed subsequently for total P, soluble P, and total suspended solids in the laboratory. Additionally, the total mass of runoff collected from each sub-plot was calculated. Results suggested that the warm season forb and warm season grass were the most effective vegetative covers for the reduction of runoff P, followed by coastal Bermuda and cool season grass, respectively. The lesser amount of runoff total P in these two treatments was due to lesser runoff mass and lesser sediments in the runoff due to initial interception of rain and less raindrop impact on soil because of denser vegetative cover in both treatments compared to all other treatments.

In Östersund there are a few stormwater ponds and oil separation units   connected to the stormwater network, but mostly there is no systems for   filtration of stormwater before it is released into a nearby lake which acts   as Östersund’s source of drinking water. In the Industrial area in Lugnvik there   is an oil separation unit connected to the stormwater network but no other   means of filtration. This study will be conducted as a case study for the   industrial part of catchment area 6 of the municipality of Östersund’s   stormwater system, where this area acts as an example to apply the   dimensioning methods on. Aside from grease (O/G) residues that might be   removed by the oil separation unit, pollutants such as heavy metals,   nutrients and suspended solids (SS) are present in the area. Which will make   its way to the lake trough the existing stormwater system. One way to   filtrate stormwater is to construct an open vegetated stormwater system,   where the water is filtered as it passes through the vegetation and/or   infiltrates to the ground and/or trough sedimentation. The purpose of this study is to evaluate some commonly used for Sweden   relevant methods for dimensioning open stormwater systems. The evaluation is   to see if the methods result in a system size that would give a satisfactory   removal of heavy metals, or if the methods is not suitable to use for   dimensioning a vegetated stormwater system if the purpose is to remove heavy   metals. The study should give answers to if currently and commonly used   methods for dimensioning open stormwater systems is suitable to use for   dimensioning of open vegetated stormwater systems by relating the results to   real examples when the purpose of the open stormwater system is to reduce   heavy metal concentrations. Further, the study shall help to identify   important factors that regulates the removal rate of heavy metals as well as   determine what particle size that should be targeted to reach a satisfactory   removal rate of heavy metals. A conclusion if   the dimensioning methods is suitable to use or not is difficult to draw as   the size of the system depends on what values that are used to calculate the   stormwater flow. Therefore, there is a large variation in the resulting   system size. To add to this uncertainty, the projection that is based on   measurements on real systems is not accurate as this only use the size of the   system in relation to the size of the impervious catchment area as a factor   for heavy metal removal. In reality this is not the case, which is indicated   by the R2-values of these projections. Other factors that in this study is   confirmed to have an impact on the removal rate is particle size, surface   load/flow, and in the case of vegetated filter strips the slope of the   filter. The particle size that should be targeted is likely within the range   of 45-65 μm. / <p>20181116</p>

Many pesticides are listed as possible or probable human carcinogens, leading to a public concern over their environmental impact. Vegetative filter strips (VFS) have been developed to intercept runoff water and prevent pesticides from contaminating surface and ground water. The first half of this project identified five plants (big blue stem, blue flag iris, eastern gama grass, prairie cord grass and wool grass) that best removed pesticides from contaminated soil. The current study evaluated four treatment groups: the five selected plant species arranged (1) randomly, (2) in a succession from short (upslope) to tall (downslope), (3) turfgrass cut to three heights from short (upslope) to tall (downslope) and (4) unvegetated (UVFS), in an effort to optimize vegetative filter strips to reduce the movement of pesticides contained in runoff from turfgrass environments. Simulated rainfall was applied to 12 VFS (0.91 m x 4.6 m x 1.83 m), each with a 5% slope. The VFS were used to evaluate the effect of three vegetated treatments on the effectiveness of VFS for mitigation of pesticide-contaminated runoff from treated turf. For the runon simulation, five pesticides (chlorothalonil, chlorpyrifos, imidacloprid, pendimethalin, and propiconazole) were added at 5% their maximum application rate for turfgrass to a nurse tank containing the amount of runoff expected to occur from an uphill turf plot (5.5 m2) during either a 1- (6.1 cm) or 5-yr (9.65 cm) rain event. Runoff samples were collected at the downhill base (bottom) of each VFS and analyzed for pesticides to determine the effectiveness of VFS at mitigating runoff water and the pesticides contained. Soil core and soil pore water samples were taken periodically post-application. All samples were analyzed for applied pesticides and quantified by GC/MS and LC/MS/MS. All vegetated treatments were more effective in decreasing the runoff volume and the associated pesticide concentration when compared with UVFS, with turfgrass being the most effective of the three treatments. This research validates the use of VFS in slowing the flow of runon water significantly enough for it to infiltrate into the soil, instead of leaving the VFS as runoff. VFS are already suggested as a best management practice to prevent pesticides from leaving many agricultural sites treated with pesticides, but this research suggests their widespread use on golf courses, parks, athletic fields and home lawns could greatly reduce the amount of pesticides in runoff waters from turf environments and help keep our waterways clean.

abstract: Vegetative filter strips (VFS) are an effective methodology used for storm water management particularly for large urban parking lots. An optimization model for the design of vegetative filter strips that minimizes the amount of land required for stormwater management using the VFS is developed in this study. The resulting optimization model is based upon the kinematic wave equation for overland sheet flow along with equations defining the cumulative infiltration and infiltration rate. In addition to the stormwater management function, Vegetative filter strips (VFS) are effective mechanisms for control of sediment flow and soil erosion from agricultural and urban lands. Erosion is a major problem associated with areas subjected to high runoffs or steep slopes across the globe. In order to effect economy in the design of grass filter strips as a mechanism for sediment control & stormwater management, an optimization model is required that minimizes the land requirements for the VFS. The optimization model presented in this study includes an intricate system of equations including the equations defining the sheet flow on the paved and grassed area combined with the equations defining the sediment transport over the vegetative filter strip using a non-linear programming optimization model. In this study, the optimization model has been applied using a sensitivity analysis of parameters such as different soil types, rainfall characteristics etc., performed to validate the model / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2015

Master of Science / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / A field study was conducted at Fort Riley, Kansas from late spring to early winter of 2007 to investigate the ability of vegetated filter strips (VFS) to attenuate pollutants resulting from military activities, the impact of different management practices (i.e. burning and mowing) on VFS performance, and the effects of vegetation on hydrological components of VFS, especially infiltration and runoff. Two native tallgrass VFS sites, each comprising three plots, located in the military training area of Fort Riley were used for this study. Fifteen rainfall events were simulated on each site along with overland application of water containing nitrogen (N), phosphorous (P) and sediment. At the end of the season both VFS were managed by mowing or burning and a final rainfall simulation was done. Variables including rainfall, infiltration, runon, runoff, above ground biomass density, pollutant concentrations of runon and runoff, and soil moisture were measured and used in the data analysis. Hydrograph development, water balance, and mass balance calculations were carried out in order to calculate the pollutant trapping efficiencies (PTE) of the VFS. Statistical analysis was done by fitting several regression models. Mean comparisons were also done for variables and variance was decomposed into time, plot and site effects at an alpha = 0.05. Results showed that on average the VFS attenuated 84 % of total nitrogen, 24 % of total phosphorous and 95 % of sediments. Regression models showed that infiltration percentage and biomass density have a positive correlation with PTE. Runoff volume and PTE were negatively correlated. Soil moisture was negatively correlated with infiltration and time to runoff. With increasing biomass density, percentage of water infiltrating and time of concentration increased. Management practices, especially burning, tended to reduce PTE. Also, both management practices reduced infiltration percentage and time of concentration. PTE reduced with intensifying rainfall and increased when rainfall faded off. Phosphorous was the most sensitive pollutant for intense storm conditions followed by nitrogen, while sediment was comparatively insensitive.

In 2011, the Deep River Portage-Burns Waterway Watershed was identified as a priority in the Northwest Indiana watershed management framework by the Northwester Indiana Regional Planning Committee. 319 grant cost-share programs were initiated in effort of maintaining and restoring the health of Deep River Portage-Burns Waterway Watershed. A watershed management plans have been developed for this watershed which proposed the implementation of vegetated filter strips (VFS) as an option. In this thesis work, the effectiveness of VFS as a best management practice (BMP) for the Deep River system was evaluated using a hydrological model scheme. <div><br></div><div>In this research, a Nonpoint Source Pollution and Erosion Comparison Tool (NSPECT) model and a Soil Water Assessment Tool (SWAT) model were constructed with required watershed characteristic data and climate data. The initial hydrologic and nutrient parameters of the SWAT model were further calibrated using SWAT Calibration and Uncertainty Programs (SWAT_CUP) with historical flow and nutrient data in a two-stage calibration process. The calibrated parameters were validated to accurately simulate the field condition and preserved in SWAT model for effectiveness analysis of BMP implementations. </div><div><br></div><div>To evaluate the effectiveness of VFS as a BMP, four different scenarios of VFS implementations along the Turkey Creek was simulated with the calibrated SWAT model. With the implementation of VFS in the tributary subbasin of Turkey Creek, the annual total phosphorus (TP) of the VFS implemented subbasin was reduced by 1.60% to 78.95% and the annual TP of downstream subbasins were reduced by 0.09% to 55.42%. Daily percentage of TP reductions ranged from 0% to 90.3% on the VFS implemented subbasin. Annual TP reductions of the four scenarios ranged from 28.11 kg to 465.01 kg.<br></div>

This study focused on development of a continuous watershed-scale modelling approach capable of evaluating sediment removal performance of vegetative filter strips (VFS). This was done by integrating the single-event hydrologic and sediment transport model AGNPS with the event-based VFS model (VFSMOD) applying the methodology developed by Sebti and Rudra (2010), and also through the development and incorporation of sub-models capable of describing changes in hydrologic conditions between rainfall events into the integrated models. For modeling purposes, the buffer zone is divided to segments called “buffer cells”. The upstream source area corresponding to each buffer cell and the flow-path connecting the area to the stream are identified, and runoff and sediment generated within each area is simulated for each event applying AGNPS. Using VFSMOD, performance analysis of VFS is conducted for each buffer cell. By applying the developed “continuous simulation” sub-models the hydrologic conditions prior to each event were determined.

Les pollutions par les xénobiotiques, en particulier les pesticides, et les métaux lourds issus des activités agricoles présentent une grande complexité de composition chimique et de dynamique spatio-temporelle. La présence de bandes enherbées entre les parcelles cultivées et les cours d’eau permet une limitation de la diffusion de ces pollutions résiduelles vers les milieux naturels. Le compartiment végétal de ces bandes enherbées peut jouer de multiples rôles dans ce contexte de protection environnementale. L’étude comparative réalisée in situ et en conditions contrôlées de laboratoire a permis de mettre en évidence le rôle biologique du compartiment végétal avec son implication directe dans les processus in planta d’absorption, de stockage et/ou de dégradation au moins partielle. Un tel rôle phytoremédiateur est dépendant de la capacité des plantes à se maintenir sur ces milieux pollués, qui diffère selon l’espèce considérée et structure ainsi les communautés végétales des bandes enherbées. L’étude intégrative en conditions contrôlées des réponses des plantes aux interactions avec les xénobiotiques à faibles doses, à différentes échelles de complexité du fonctionnement végétal, a permis de montrer les effets de ces stress chimiques chez l’espèce modèle Arabidopsis thaliana et chez l’espèce prairiale Lolium perenne. Les xénobiotiques et les métaux lourds à des doses subtoxiques ont induit d’importants bouleversements métabolomiques et moléculaires chez ces espèces, avec des effets cryptiques de ces polluants et de leurs produits de dégradation. L’analyse en conditions de multi-pollution, qui reflètent de manière réaliste les pollutions péri-agricoles, a montré la complexité et la difficulté de prédiction des interactions entre les effets des contaminants en mélange. Ces mécanismes de réponses diffèrent selon l’espèce et le polluant et laissent supposer des divergences en termes de perception et/ou de transport des polluants, ou de coordination des réponses moléculaires et métaboliques. Arabidopsis a ainsi présenté une coordination de ses réponses orientée vers une augmentation des métabolites de stress, et une diminution des métabolites carbonés (sucres solubles), en parallèle de modifications de l’expression de gènes impliqués dans les défenses antioxydantes, les défenses contre les stress xénobiotiques, ou dans la dynamique des phytohormones. Le stress chimique a entraîné chez Lolium des modifications majeures du métabolisme azoté, ainsi qu’un remaniement des processus de photorespiration. L’analyse transcriptomique de cette espèce a de plus montré que la majorité des gènes identifiés sont impliqués dans des voies de transduction de signal, montrant ainsi la complexité des mécanismes de réponse et les couplages qui existent entre les signaux métaboliques, en particulier liés aux sucres, les voies de signalisation associées aux phytohormones, les signaux de stress et la photosynthèse. / Environmental pollutions by xenobiotics, especially by pesticides and heavy metals derived from agricultural activities, show an important complexity of chemical composition and of spatiotemporal dynamic. Vegetative filter strips between cultivated fields and streams limit the diffusion of these residual pollutions to natural environments. However, the exact biological role of plant in these buffer strips is poorly understood in this context of environmental and ecological protection. A comparative study carried out in situ and in controlled conditions highlighted the role of plant compartment in the processes of absorption, storage and/or partial degradation of pollutants in planta. Such capability of phytoremediation depends on the maintenance of a vegetal cover in area subjected to recurring flow of pesticides, it varies according to species and leads to the structuration of vegetative filter strip communities. An integrative study in controlled conditions of plant responses to low doses of pollutants allowed to analyze at different levels of complexity the impacts of chemical stresses on the model species Arabidopsis thaliana and the grassland species Lolium perenne. Low and sublethal doses of xenobiotics, associated degradation products and heavy metals induced cryptic perturbations at metabolic and molecular levels. Multi-pollution analyses, which reflect realistic conditions of environmental exposure, highlighted complex interactive effects between pollutants in mixture and the difficulty to predict them. The mechanisms of response to these chemical stresses differ according to the species and the pollutant, and suggest differences in term of perception and/or transport of pollutants, or of coordination of molecular and metabolic responses. Arabidopsis presented a coordination of its responses toward an increase of stress metabolites, a decrease of carbon metabolites (soluble carbohydrates), in parallel with modifications of gene expressions implicated on antioxidant defences, defence against xenobiotic stresses, or phytohormone dynamic. Chemical stress leads to major modifications of nitrogen metabolism in Lolium, and perturbations of processes of photorespiration. De novo transcriptomic analysis of Lolium therefore showed that a majority of identified genes are related to signal transduction pathways, highlighting the complexity of response mechanisms and the links between metabolic signals, especially linked to carbohydrate, hormonal signaling pathways, stress signals and photosynthesis. Subtoxic chemical stress induced cryptic re-engineering of plant processes that may explain the development of tolerance for some species and their persistence in area affected by residual pollution.

<p>Field-edge buffers are a promising way to address nonpoint source pollution from agricultural runoff, but concentrated runoff flow often renders standard fixed-width linear buffers ineffective. AgBufferBuilder (ABB) is a tool within ESRI ArcMap Geographic Information Systems software that designs and evaluates targeted, nonlinear buffers based on hydrologic modeling and other field-specific parameters. We tested ABB on n=45 Areas of Interest (AOIs) stratified based on estimated sediment loading across three sub-watersheds within Michigan’s Saginaw Bay watershed to evaluate the effectiveness of ABB relative to existing practices across a wide range of landscape conditions. We modeled tractor movement around ABB buffer designs to assess more realistic versions of the likely final designs. ABB regularly failed to deliver the desired 75% sediment capture rate using default 9 m x 9 m output raster resolution, with Proposed buffers capturing from 0% to 68.49% of sediment within a given AOI (mean=37.56%). Differences in sediment capture between Proposed and Existing buffers (measured as Proposed – Existing) ranged from -48% to 66.81% of sediment (mean=24.70%). Proposed buffers were estimated to capture more sediment than Existing buffers in 37 of 45 AOIs, representing potential for real improvements over Existing buffers across the wider landscape. In 13 of 45 AOIs, ABB buffers modified for tractor movement captured more sediment than Existing buffers using less total buffer area. We conducted a collaborative design process with three Saginaw Bay watershed farmers to assess their willingness to implement ABB designs. Feedback indicated farmers may prefer in-field erosion control practices like cover cropping and grassed waterways over field-edge ABB designs. More farmer input is needed to better assess farmer perspectives on ABB buffers and to identify preferred data-based design alternatives. Engineered drainage systems with raised ditch berms and upslope catch basins piped underground directly into ditches were encountered several times during site visits. ABB only models surface flow and does not recognize drain output flow entering waterways. Modified ABB functionality that models buffers around drain inlets would greatly improve its functionality on drained sites. This may be accomplishable through modification of user-entered AOI margins but requires further investigation. Unfortunately, the existing tool is built for outdated software and is not widely accessible to non-expert users. We suggest that an update of this tool with additional functionality and user accessibility would be a useful addition in the toolbox of conservation professionals in agricultural landscapes.</p>