Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / William P. Winslow III / This project is of a personal interest to me, because Junction City, Kansas has been my home town since birth. The city is a rapidly growing community with a strong military presence from nearby Fort Riley, Kansas. The project will explore the capacity for effective growth while preventing the degradation of fragile natural resources within the community. It will also provide new amenities for the people of Junction City as well as capitalize on the existing natural amenities. The project provides storm water management solutions for an existing retail development and a proposed mixed use development incorporating sustainable practices. Studying the history and progressive nature of Junction City provides an understanding of how to embrace the design within the surrounding landscape. A model for responsible mixed use retail and residential development in Junction City is provided through this project. Storm water best management strategies were also implemented to improve the oxbow wetlands by capturing the first flush storm event as well as a 25 year storm event. Finally, the project should continue to shape the history and enthusiasm of Junction City and its people.

Ett framtida varmare klimat förväntas öka vår nederbörd i Sverige. Kraven på hur man ska omhänderta dagvatten har förändrats och skärpts de senaste åren vilket har gjort att nya dagvattensystem har börjat tas i bruk. Rapporten går igenom hur man valt att lösa dagvattenfrågan i ett nyproducerat bostadsområde utfört av ett stort byggföretag. I området har man valt att omhänderta dagvattnet lokalt, det vill säga att dagvatten fördröjs och rengörs i det drabbade området. Genom att utnyttja markens förutsättningar kombinerat med tekniska lösningar har det skapats ett dagvattensystem som ska leva upp till samhällets ställda krav. Rapporten redogör för dimensioneringsmetoder av dagvattensystem som visar att små förändringar i ett stort system kan ge stora följder för systemets funktion. För att ett system ska fungera under en längre tidsperiod så krävs det att man underhåller systemet efter en framtagen underhållsplan som redovisas i rapporten. För att systemet ska kunna underhållas effektivt så har undersökningen tagit fram tre förslag på dagvattenbrunnar med tillhörande magasin som ska underlätta underhåll och reducera flödesstörningar. / In the future we expect a warmer climate and the warmer temperatures will increase the rainfall in Sweden. How we disposes our stormwater have in the recent years got stricter requirements which resulted in new stormwater systems has been put in use. The report describes a stormwater system in a residential area developed by a large building company. In the area the stormwater is been taken care of inside the intended area. With this means that stormwater is being delayed and purified within the affected area. By using the ground conditions in the area together with technical solutions a system has been created to live up to the society’s set requirements. The report describes the sizing methods of stormwater systems that show that small changes in a large system can have a major impact on the functioning of the system. For a system to function for a longer period of time, It’s necessary to maintain the system after a planned maintenances plan witch this report presents. In order for the system to be able to be maintenance effectively in future, the study has developed three proposals for the design of stormwaterwells with associated magazines to facilitate maintenance and reduce flowdisturbances.

Runoff from paved surfaces in the urban environment is recognised as a major contributing source to deteriorated water quality. In stormwater, both various metals and organic compounds can be present and the quality of stormwater is dependent on e.g. the characteristics of the surfaces that the runoff encounters. Diffuse pollution sources, i.e. anthropogenic emissions from e.g. traffic or constructions, has been pointed out by the European Water Framework Directive to significantly contribute to pollution of stormwater receivers. In order to create and obtain a sustainable, liveable and aesthetical urban environment it is critical to be able to mitigate stormwater pollution, not least considering the increasing amount of stormwater due to climate change.The aim of this master’s thesis was to evaluate the potential release of inorganic- and organic stormwater pollutants from conventional roofing materials by laboratory leaching experiments. The study was mainly aimed to serve as a first screening on the roofing materials, in order to be able to select a number of materials for further investigation later on. The organic compounds included in this study were polycyclic aromatic hydrocarbons, nonylphenols and -ethoxylates, phthalates and herbicides. Previous research on stormwater pollution has mainly focused on metals and there is therefore a knowledge gap on organic compounds in urban runoff. The leaching experiments were designed considering previous similar studies. Synthetic rainwater was prepared based on measurements of rainwater quality in Sweden. Duplicates of 16 commonly used roofing materials were prepared and immersed in beakers of synthetic rainwater. The beakers were agitated on an orbital shaking device for 24 hours and pH as well as conductivity was recorded in the leachates before sending the samples to the contracted laboratory for analysis. Metals were analysed on all materials and the organic compound analyses were performed on selected materials based on each material’s composition and was limited with the substance’s probability to release from each material.From the analysis results, mean values for the leached concentrations of all duplicates were calculated. The annual potential release of substances from materials was estimated based on the leached concentrations and data on the average annual precipitation in Sweden, in order to get an indication of the order of magnitude of the pollutant release. The results showed a potential release of a number of the included substances from many of the studied roofing materials, in varying order of magnitude. The shingle roofing was the material that showed the ability to release the largest number of pollutants. Some materials e.g. the clay tile also showed potential to adsorb substances on the material surface. Metals were mainly released in dissolved form from most materials. Phthalates were not present in concentrations above report limits in the leachates from any of the studied materials. The results also indicate a significant different in the release potential from materials that were considered similar in their composition and expected to have similar leaching behaviour prior to the laboratory experiments, e.g. two similar felt roof materials from different manufacturers. / <p>Validerat; 20150715 (global_studentproject_submitter)</p>

Microplastic pollution as a global environment problem in marine systems has substantially raised public concern in recent years. In 2016, the Swedish Environmental Protection Agency performed a study about potential sources and pathways of microplastics spreading to the marine environment. Microplastics from artificial turfs have been recognized as the second most important source of microplastic emission in Sweden. Between 1640 to 2460 tons per year of microplastics are estimated to be lost from artificial turfs. The lost microplastics are potentially transported to stormwater wells by runoff during rainfall events, eventually reaching marine environments. This study aims to track microplastics from artificial turfs to stormwater wells. Since the research of microplastic in stormwater has so far shown to be limited, field work and laboratory analysis have been developed in this study. Four artificial football fields located in Stockholm municipality were taken as sampling sites. First, pathways for microplastics from artificial turfs to stormwater were investigated. Second, the characteristics of microplastic granulates infill used in the football fields have been analyzed. Finally, stereo microscopy was used to visually identify microplastics in stormwater. The results showed that rainfall as a driving force of runoff process contributes to microplastics transport from artificial turfs to stormwater. During this transport process, a fraction of microplastics is captured by the soil. The size of microplastic granulates identified not only in stormwater but also in stormwater sediments is typically between 1 mm to 3 mm. Due to its limitations, stereo microscopy is quite a subjective method for identifying microplastics and thus not suitable for quantitative analysis, since microplastic particles are comparable in size to and visually difficult to differentiate from organic particles co-occurring in stormwater. In order to accurately quantify the amounts of microplastics transported to stormwater systems from artificial turfs, it is necessary to develop new methods for microplastics identification. This study presented an attempt in this direction, highlights its limitations, and discusses more suitable alternatives.

This thesis project monitors the quantity and quality of stormwater entering and leaving a bioretention system in Coralville, Iowa. Bioretention is among many engineered solutions designed to provide treatment for runoff that might otherwise be drained directly to a body of water. Increased quantities of stormwater can impact stream morphology, degrade aesthetics, increase flood frequency, peak flow, and peak duration; as well as increased sedimentation and sediment transport. Decreases in water quality can impair fish or other aquatic populations, and increase the treatment requirements for downstream intakes. The number of communities, presently 47, affected by stormwater control ordinances increases as the Environmental Protection Agency continues to require smaller Municipal Storm Sewer Systems to adhere to National Pollutant Discharge Elimination System permits. The City of Coralville is setting an example by using infiltration practices to treat runoff from a 4-lane divided thoroughfare. Preliminary monitoring shows that the system in Coralville provides an average reduction in effluent temperature g of 3.7°C, an average reduction in peak flow of 2 cfs, and an average peak delay of 45 minutes. The project provides infiltrative treatment for the water quality volume and the empirical curve number for the project is 77.4. The urban runoff to the project is within literature values and the pollutant concentrations in the project effluent are below legal limits.

Nitrate (NO3) loadings from stormwater runoff promote eutrophication in surface waters. Low Impact Development (LID) is a type of best management practice aimed at restoring the hydrologic function of watersheds and removing contaminants before they are discharged into ground and surface waters. Also known as rain gardens, a bioretention system is a LID technology that is capable of increasing infliltration, reducing runoff rates and removing pollutants. They can be planted with visually appealing vegetation, which plays a role in nutrient uptake. A modified bioretention system incorporates a submerged internal water storage zone (IWSZ) that includes an electron donor to support denitrification. Modified (or denitrifying) bioretention systems have been shown to be capable of converting NO3 in stormwater runoff to nitrogen gas through denitrification; however, design guidelines are lacking for these systems, particularly under Florida-specific hydrologic conditions. The experimental portion of this research investigated the performance of denitrifying bioretention systems with varying IWSZ medium types, IWSZ depths, hydraulic loading rates and antecedent dry conditions (ADCs). Microcosm studies were performed to compare denitrification rates using wood chips, gravel, sand, and mixtures of wood chips with sand or gravel media. The microcosm study revealed that carbon-containing media, acclimated media and lower initial dissolved oxygen concentrations will enhance NO3 removal rates. The gravel-wood medium was observed to have high NO3 removal rates and low final dissolved organic carbon concentrations compared to the other media types. The gravel-wood medium was selected for subsequent storm event and tracer studies, which incorporated three completely submerged columns with varying depths. Even though the columns were operated under equivalent detention times, greater NO3 removal efficiencies were observed in the taller compared to the shorter columns. Tracer studies revealed this phenomenon was attributed to the improved hydraulic performance in the taller compared to shorter columns. In addition, greater NO3 removal efficiencies were observed with an increase in ADCs, where ADCs were positively correlated with dissolved organic carbon concentrations. Data from the experimental portion of this study, additional hydraulic modeling development for the unsaturated layer and unsaturated layer data from other studies were combined to create nitrogen loading model for modified bioretention systems. The processes incorporated into the IWSZ model include denitrification, dispersion, organic media hydrolysis, oxygen inhibition, bio-available organic carbon limitation and Total Kjeldahl Nitrogen (TKN) leaching. For the hydraulic component, a unifying equation was developed to approximate unsaturated and saturated flow rates. The hydraulic modeling results indicate that during ADCs, greater storage capacities are available in taller compared to shorter IWSZs Data from another study was used to develop a pseudo-nitrification model for the unsaturated layer. A hypothetical case study was then conducted with SWMM-5 software to evaluate nitrogen loadings from various modified bioretention system designs that have equal IWSZ volumes. The results indicate that bioretention systems with taller IWSZs remove greater NO3 loadings, which was likely due to the greater hydraulic performance in the taller compared to shorter IWSZ designs. However, the systems with the shorter IWSZs removed greater TKN and total nitrogen loadings due to the larger unsaturated layer volumes in the shorter IWSZ designs.

In the light of increasing demand and diminishing supplies a sustainable urban water management for Melbourne and other cities will need to include water recycling and reuse of reclaimed water and stormwater. One key issue in stormwater reuse is the need for storage between times of collection until times of demand. Aquifer storage and recovery (ASR) would be a valuable option as it has limited space requirements and restricts loss from evaporation. However, stormwater commonly contains elevated levels of heavy metals, of which Zn and Cu are the most mobile. Stormwater also contains suspended solids, organic carbon, oxygen and nutrients, which influence the behaviour of injected metals and induce geochemical changes in the aquifer. While stormwater ASR has been practiced in limestone aquifers in South Australia, field data for sandy aquifers, which are more prevalent around Melbourne, are very limited. Risk assessment regarding the potential impact of stormwater ASR on the quality of the aquifer and groundwater resources in sandy aquifer is therefore necessary. After a characterisation of stormwater from different Melbourne catchments confirmed comparatively high concentrations of Zn and Cu in stormwater, three siliceous aquifer sediments were used in a series of batch sorption experiments as well as column experiments imitating one ASR cycle to assess the impact of different parameters on Zn and Cu behaviour. The reactive geochemical transport model PHT3D was then modified to simulate experimental results with the outlook that it could be used as a predictive tool for long term evaluation. The study showed that Zn adsorption was limited and desorption of large fractions occurred, indicating that injected amounts of Zn are mobile and would mainly be recovered. In contrast, Cu adsorption was higher and desorption was limited, indicating that injected amounts of Cu would mainly accumulate in the aquifer. The release of metals was triggered by reduction in pH, increase in ionic strength and particle mobilisation. Metal concentrations were also increased after storage phases, while minor sediment constituents, especially organic matter, significantly reduce metal mobility. The different role of dissolved and solid organic carbon is critical in understanding Cu behaviour during stormwater ASR. Pretreatment of stormwater to reduce the injection of colloids, organic carbon and metals are recommended to limit metal accumulation in the subsurface. Monitoring of water quality throughout the ASR cycle would be encouraged to validate the current findings with field data. Special attention should be paid to backflushed water quality to ensure correct disposal.

University of Technology, Sydney. Faculty of Engineering. / Although extensive worldwide literature on urban stormwater runoff exists, very few publications describe runoff development in terms of its basic building blocks or processes and their individual and accumulative significance in response to varying inputs and boundary conditions. Process algorithms should respond accurately to varying input magnitudes and characteristics as well as to changes in antecedent conditions. The present state of estimation errors involved in many current numerical simulation techniques has been reviewed in this thesis. A significant amount of errors that are presently encountered for have been explained in terms of undefined process response not explicitly included within many modelling methodologies. Extensive field monitoring of intra-catchment rainfall and runoff within an urban catchment at Giralang in Canberra, which is typical of Australian urban catchments, was carried out over a 3-year period to define and measure individual runoff processes. This monitoring work led to a greater understanding of the processes driving the aggregation of local runoff from many sub-areas into the runoff observed at full catchment scale. The results from the monitoring process prompted a number of approaches to potentially reduce standard errors of estimate from model-attributable errors based on improvements to definable catchment response mechanisms. The research isolated a number of basic building blocks associated with typical residential allotments, that can be grouped into roof drainage, yard drainage and adjacent road drainage. A proposed modelling approach was developed that allowed these building blocks at an allotment scale to be simply computed using storage routing techniques. This then aggregated via the total catchment’s public drainage system isochronal characteristics utilising a “process tree” approach to provide full catchment scale runoff response. The potential reduction in estimation errors utilising the developed procedure was assessed using a large number of recorded events from the Giralang catchment monitoring data. The proposed numerical modelling approach was found to provide significant improvements over current methods and offered a scale-independent and stormindependent methodology to model catchments of any size without the need for changes to any of the runoff routing parameters. Additionally the approach permits the flexible sequencing and inclusion of a wide range of different urban drainage structures within a catchment that are representative of the local characteristics. The developed procedure also includes a spatially varied water balance approach to infiltration estimation that is more suited to future continuous simulation models. The developed “flexible process tree” approach provides an important step forward in the numerical modelling of complex urban drainage systems. This can reduce errors of estimate by improving intra-catchment process representation.

Stormwater impoundments are one of many types of best management practices (BMP) designed and implemented to regulate water quantity and improve the quality of runoff from urban areas. Studies of water quality in urban impoundments have indicated that conventional designs are however, not very effective at removing solids and associated pollutants. Accordingly, many urban impoundments are being re-designed to improve downstream water quality. However, few studies have systematically monitored and quantified post-design water quality improvements of urban impoundments. This thesis examines changes in the water quality performance of an urban impoundment (Columbia Lake) in Waterloo, Ontario resulting from redesign of the lake for the pre-design period (2003 and 2004) and the post-design period (2006 and 2007). To achieve this goal, four years of water quality data collected at the inlet and outlet of Columbia Lake as part of the Laurel Creek Monitoring Program was measured. Water chemistry parameters included total phosphorus (TP), soluble reactive phosphorus (SRP), suspended solids (SS), dissolved oxygen (DO), pH and total dissolved solids (TDS). Inlet and outlet discharge (Q) were measured to determine the water retention time in the lake. Concentrations and loads of TP and SS for the post-design period (2006 and 2007) were compared to those for the pre-design period (2003 and 2004). During the pre-design period (2003 and 2004), inflow TP concentrations ranged from 18 to 372 µg L-1 with an average (mean ± standard error) of 56±7 µg L-1, while outflow TP concentrations ranged from 37 to 266 µg L-1 with an average of 116±6 µg L-1. Post-design TP concentrations ranged from 10 to 124 µg L-1 with an average of 53±5 µg L-1 and from 14 to 147 µg L-1 with an average of 44±3 µg L-1 at the inflow and outflow, respectively. Pre-design SS concentrations ranged from 1.8 to 168.5 mg L-1 with a mean of 19.0±3.2 mg L-1 and from 4.0 to 194.7 mg L-1 with a mean of 66.6±4.7 mg L-1 at the inflow and outflow, respectively. Post-design SS concentrations varied from < 0.1 to 25.8 mg L-1 with an average of 8.5±0.8 mg L-1 and from < 0.1 to 42.5 mg L-1 with an average of 14.5±0.8 mg L-1 at the inflow and outflow, respectively. Sedimentation/resuspension dominated the TP and SS transfer via Columbia Lake. Pre-design TP loads (log-transformed) strongly correlated with SS loads at the inflow and outflow (r = 0.661 and 0.777, p = 0.0001). These parameters were more strongly correlated during the post-design period (r = 0.794 and 0.915, r = 0.0001), which indicates that particulate P (PP) was a dominant fraction of TP and that the release of dissolved phosphorus (DP) from bottom sediments was considerably decreased following the redesign. No significant difference was observed between inflow and outflow SRP concentrations. Discharge strongly affected TP and SS loads at the inflow and outflow during the pre- and post-design periods (r > 0.79, p = 0.000 for all). After the redesign of Columbia Lake, the average net internal P loading rate decreased from 198% to 22% for TP. The primary factor influencing the observed decreased post-design TP and SS outputs was the removal of sediment from the lake. Bottom sediment removal and changes to the lake bathymetry reduced sediment resuspension and P desorption, which decreased the average net internal SS loading rate from 828% to 154%. The Columbia Lake Water Quality Model developed by Stantec Consulting Ltd. (2004) underestimated the post-design outflow TP and SS concentrations mainly because it did not include terms that account for factors such as bioturbation, wave induced resuspension and biological activity.

Stormwater (SW) runoff in urban areas represents a major pathway for pollutant transfer to receiving waters. Best management practices (BMP) were introduced in the 1970s to help mitigate the negative effects of SW. In the 1990s, Stormwater management (SWM) ponds were established as a BMP to help increase the water quality of SW effluent. Many SWM ponds do not provide sufficient water quality treatment. Information on the internal processes influencing the reduction of total phosphorus (TP), soluble reactive phosphorus (SRP) and total suspended solid (TSS) concentrations in SWM ponds with different designs is lacking. Knowledge of the processes affecting TP, SRP and TSS retention can help improve the design of SWM ponds to enhance their treatment performance. The purpose of this thesis is to provide an assessment of the internal chemical processes that affect the trap efficiency (TE) and spatial and temporal variability of TP, SRP and TSS concentrations at two structurally different SWM ponds (Pond 45; conventional and Pond 33; hybrid extended detention) in Waterloo, ON. Water samples were collected at the inflow and outflow at the two SWM ponds during six storm events and 30 baseflow periods. A mass balance approach was used to quantify the TE of TP, SRP and TSS concentrations at each pond. Pond 33 had a TE of 24.3%, 26.7% and 66.8% for baseflow and stormflow samples of TP, SRP and TSS. Pond 45 performed much better with TE of 93.8%, 94.2% and 98% for TP, SRP and TSS concentrations. Pond 33 was a source of TP, SRP and TSS for 3, 4 and 2 storm events sampled during the field season, respectively. Pond 45 was a sink for all parameters on all storm events samples. The spatial and temporal variability of TP, SRP and TSS concentrations were examined to improve knowledge of external factors and internal processes that influence the TE of SWM ponds. The effects of storm magnitude, seasonality and vegetation growth and senescence on effluent water quality were investigated. Additionally, the role of sediment on P cycling in the ponds was evaluated by determining grain size distribution, porewater SRP concentrations, sediment geochemistry and mineralogy, and the sediment P buffering capacity. Vegetation senescence, anoxic conditions, porewater SRP concentrations, sediment characteristics and buffering capacity influenced the poor TE at Pond 33. Pond 45 had more favourable water column conditions, i.e. higher dissolved oxygen concentrations, therefore allowed greater amounts of P to adsorb onto sediment. Design and maintenance considerations are described to help improve the performance at Pond 33. Continual water quality monitoring of SW effluent will identify changes in quality and mitigation measures can be implemented to increase a SWM ponds performance.