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Value of Rain Gardens in Winnipeg: The Ecole St. Avila Rain Garden Case StudyChen, Hao 26 June 2012 (has links)
With rising concern about flooding and water pollution in the Red River and particularly in Lakes Manitoba and Winnipeg in recent years, building rain gardens in cities may become one solution with considerable potential for improving water quality. The literature illustrated the many benefits that can be provided by a rain garden system, not only aesthetically pleasing gardens with educational and biodiversity values, but they also can reduce storm water pollution and flooding in downstream water bodies.
In order to address questions of public understanding and perceptions of their usefulness so as to better promote future implementation, the study examined social feedback about rain gardens through a survey at Ecole St Avila, an elementary school in Winnipeg. The findings from the survey indicated that the largest obstacles for rain garden development are funding and the lack of knowledge by the public.
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Value of Rain Gardens in Winnipeg: The Ecole St. Avila Rain Garden Case StudyChen, Hao 26 June 2012 (has links)
With rising concern about flooding and water pollution in the Red River and particularly in Lakes Manitoba and Winnipeg in recent years, building rain gardens in cities may become one solution with considerable potential for improving water quality. The literature illustrated the many benefits that can be provided by a rain garden system, not only aesthetically pleasing gardens with educational and biodiversity values, but they also can reduce storm water pollution and flooding in downstream water bodies.
In order to address questions of public understanding and perceptions of their usefulness so as to better promote future implementation, the study examined social feedback about rain gardens through a survey at Ecole St Avila, an elementary school in Winnipeg. The findings from the survey indicated that the largest obstacles for rain garden development are funding and the lack of knowledge by the public.
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The Effect of the Antecedent Dry Conditions on Nitrogen Removal for a Modified Bioretention SystemPeterson, Mackenzie 02 November 2016 (has links)
Eutrophication is defined as the ‘over enrichment’ of a water body from nutrients, resulting in uncontrolled growth of primary producers, leading to periods of oxygen depletion from decomposition of the algal organic matter. According to the 2010 Water Infrastructure Needs and Investment (a U.S. Congressional Report), 40% of U.S. water bodies are contaminated with pollutants, including nutrients. Non-point sources of nutrient pollution are a major cause of this reduction in water quality. One way to decrease eutrophication is to manage nutrients found in stormwater runoff, before they reach a receiving water body.
Bioretention cells containing an internal water storage zone (IWSZ) have been shown to remove higher amounts of nitrogen than conventional cells (without an IWSZ). The IWSZ contains an organic carbon substrate, usually derived from wood chips submerged in water, which supports the biochemical process of denitrification. Characteristics of wood chips that affect nitrogen removal include carbon content (%), leaching of dissolved organic carbon (DOC), and wood chip size and type. However, there is limited information on how the intermittent hydraulic loading that is associated with these field systems impacts their performance. Accordingly, the overall goal of this research is to improve understanding of the effect that the antecedent dry conditions (ADC) have on the performance of a field scale bioretention cell modified to contain an IWSZ.
The nine different types of wood chips used in laboratory and field studies identified in the literature were categorized as hardwood and softwood. Literature showed that total organic carbon (TOC) leached from softwood chips is almost double the TOC measured from the hardwood chips, 138.3 and 70.3 mg/L, respectively. The average observed nitrogen removal for softwood chips was found to be greater than the removal for the average of the hardwood chips (75.2% and 63.0%, respectively). Literature also suggests that larger wood chip size may limit the availability of the carbon for the denitrifying organisms and provides less surface area for the biofilm growth.
A field study conducted for this research compared the performance of a modified bioretention system designed to enhance denitrification, addition of an IWSZ, with a conventional system that does not contain an IWSZ. Fourteen storm events were completed from January 2016 to July 2016 by replicating storm events previously completed in the laboratory using hydraulic loading rates (HLR) of 6.9 cm/h, 13.9 cm/h, and 4.1 cm/h. The goal was to have results from storm events with ADCs of two, four, and eight days, with the varying durations of hydraulic loading of two, four, and six hours. Synthetic stormwater, simulating nitrogen levels common in urban runoff, was used as the system’s influent to assist in running a controlled experiment. The resultant ADCs ranged from 0 to 33 days, with the average ADC being 9 days. The fourteen sets of influent samples were averaged to obtain mean influent concentrations for the synthetic stormwater. These values were used when calculating the percent nitrogen removal for the four measured nitrogen species (NOx – N, NH4+– N, organic N, and TN).
The field storm events were separated into three groups based on HLR and duration to eliminate the affects of both variables on nitrogen removal for these results, since the focus is the ADC. For the low HLR (4.1 cm/hr), there were four storm events (ADCs of 4 to 33 days), as the ADC increased, greater percentages of ammonium – nitrogen, organic nitrogen, and total nitrogen were removed. For nitrate/nitrite – nitrogen, the percent removal was rather consistent for all four storm events, not significantly increasing or decreasing with changes in the ADC. There were five storm events (ADCs of 0 to 28 days) tested with the median HLR (6.9 cm/hr), nitrogen removal for all four species increased as the ADC increased. The increase was significant (p0.05) for nitrate/nitrite – nitrogen. The third group also contained five storm events (ADCs from 0 to 11 days) that were tested with the highest HLR (13.9 cm/hr). Ammonium – nitrogen, nitrate/nitrite – nitrogen, and total nitrogen all increased with the ADC, and organic nitrogen removal decreased with the increasing ADC. As a result, this research concluded that the difference in HLR affects the nitrogen removal efficiency, but overall increasing the ADC increased nitrogen removal for NOx – N, NH4+ - N, organic N, and TN.
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Využití bylin v procesu úsporného hospodaření s vodouKnotková, Kateřina January 2019 (has links)
The presented master study is focused on sustainable rain water management with emphasis on proper use of plants in the process. This thesis connects information from foreign countries and puts them into context of Czechclimatic conditions and Czechlegal and technical standards. It defines term “dešťový záhon“ (rain flower bed) as a landscape element for rainwater infiltration that combines aesthetical, ecological and water management functions. Technical aspect and assortment of usable plant species is critically evaluated. Suitable technical variants are “vsakovací průleh” (rain garden), “vsakovací průleh s rýhou” (bioretencion system) a “vsakovací průleh s rýhou a regulovaným odtokem” (bioretencion system). The study includes also few examples of realized rain water management solutions. Drought tolerant species looks surprisingly as most promising for use in “rain flower beds“. Combination of annual, biennial etc. plants is possible; however perennials are most promising, while shrubs and trees usage is limited. “Rain flower bed“ can be established by plantingor sowing. Both having its pros and cons the combination of these two approaches is apparently best, because sowing allows reduce initial costs of new greenery, while planted perennials prevents erosion and operate as structural plants. Additionally 30 plant species were tested, whether they are usable for direct sowing. Experiment was established within the grant project IGA - ZF/2018 - AP001 on April 2018 in Mendeleum grounds of Faculty of Horticulture, Lednice. Preliminary results show low germination rates that are significantly dependent on climatic conditions. Of the 30 only six can recommend for now: Achillea ptarmica, Asclepias tuberosa, Cichorium intybus, Coreopsis lanceolata ´Sterntaller´, Phuopsis stylosa, Oenothera biennis. Better results can be probably achieved by sowing plants in autumn, however results of the autumn part of the experiment will be known after submission of this work.
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Stormwater Treatment by Two Retrofit Infiltration PracticesDeBusk, Kathy Marie 13 June 2008 (has links)
Increases in impervious surfaces associated with urbanization change stream hydrology by increasing peak flow rates, storm-flow volumes and flood frequency, and degrade water quality through increases in sediment, nutrient, and bacteria concentrations. In response to water quality and quantity issues within the Stroubles Creek watershed, the Town of Blacksburg and Virginia Tech designed and constructed two innovative stormwater best management practices (BMPs). The goal of this project was to evaluate the effectiveness of a bioretention cell and a CU-Structural Soil™ infiltration trench. BMP construction was completed in July 2007. Twenty-nine precipitation events were monitored over a period of five months between October 2007 and March 2008. For each storm, inflow and outflow composite samples were collected for each BMP and analyzed for suspended sediment, total nitrogen, total phosphorus, fecal coliform bacteria and E-coli bacteria. The inflow and outflow concentrations and loads, as well as total inflow and outflow volumes and peak flow rates, were then compared to evaluate how well each BMP reduces stormwater flows, decrease peak runoff rates and improves water quality of stormwater runoff. Results for the bioretention cell indicate average reductions in stormwater quantity, sediment, total nitrogen, total phosphorus and fecal coliform bacteria that exceeded 99% by mass. The CU-Structural Soil™ infiltration trench produced reductions in stormwater quantity, total phosphorus and sediment that averaged 60%, 45% and 51%, respectively. Preliminary bacteria results indicated that both BMPs served as sources of E-coli, and the infiltration trench served as a source of fecal coliform bacteria. / Master of Science
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BIORETENTION GARDENS FOR THE REMOVAL OF NITROGEN AND PHOSPHOROUS FROM URBAN RUNOFFRandall, Mark 12 September 2011 (has links)
Bioretention gardens are stormwater management practices that offer numerous water quantity and quality benefits. However, previous studies have reported inconsistent removal of nitrogen and phosphorous in these systems. The first phase of this research involved the construction and monitoring of ten vegetated, mesoscale, bioretention cells in a field setting to provide a comparison of the performance of five alternative designs intended to provide nutrient removal. Results indicated that concentrations of total nitrogen and total phosphorous may be reduced by up to 53 and 79%, respectively, in specially designed bioretention gardens. In the second phase of the research, a GIS-based site selection tool was used to identify areas suitable for bioretention implementation based on physical site requirements. Applying this tool to selected urban catchments demonstrated that bioretention gardens may be integrated into existing urban landscapes on a scale large enough to accommodate runoff and associated nutrient loads from small (<15mm) storms.
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Bioretention for Phosphorus Removal: Modelling Stormwater Quality ImprovementsROY-POIRIER, AUDREY 27 September 2009 (has links)
Bioretention systems are best management practices (BMPs) that make use of the biogeochemical processes within a forest-type ecosystem to provide at-source stormwater retention and pollutant removal. Laboratory studies and field monitoring have shown great potential for water quantity and quality control through the use of bioretention, but reported nutrient removal has been inconsistent between these systems. In particular, the processes involved in the cycling of phosphorus within bioretention systems are not clearly understood. Some studies report high phosphorus removal from bioretention systems, while phosphorus leaching was observed in other systems.
Phosphorus is a macronutrient required by all forms of life. It is also an important water pollutant, as it controls algal growth in most freshwater environments. High phosphorus loadings to these aquatic ecosystems can lead to eutrophication, which has significant ecological, environmental and economical impacts.
The Bioretention Phosphorus Removal Model (BPRM), an event-based one-dimensional finite difference model, was developed to simulate phosphorus removal in bioretention systems. The model includes four completely-mixed layers to simulate hydrologic processes as well as both soluble and particulate phosphorus transport in a bioretention system. Model processes include evapotranspiration, infiltration, overflow, exfiltration to native soils, underdrain discharge, soluble phosphorus sorption and vegetative uptake, and particulate phosphorus capture.
Monitoring data collected by the Toronto and Region Conservation Authority (TRCA) at a bioretention system installed on Seneca College’s King City campus, in Ontario, Canada, was used to evaluate the performance of BPRM. The model was found to overestimate total underdrain discharge volumes, but total phosphorus concentration and mass predictions were found to be useful for design purposes. BPRM correctly predicted phosphorus leaching from the Seneca College bioretention system for all storm events considered but one. The model can be used by practitioners to evaluate the potential for phosphorus leaching in a bioretention system.
A detailed sensitivity analysis revealed that BPRM phosphorus transport predictions are particularly sensitive to the drainage properties of bioretention soils, which highlights the importance of hydrologic transport processes for water quality control in bioretention systems. Modelling results suggested that soluble phosphorus desorption from bioretention soils was responsible for phosphorus leaching from the Seneca College bioretention system. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-09-25 17:00:03.173
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Dagvattenhantering : Vid Sunlight i Nyköpings kommunSerra Berglund, Catharina January 2018 (has links)
Today stormwater is a growing problem and it is a hot topic for discussions. Due to the urbanization with growing cities and hard surfaces of asphalt and concrete, rainwater flows off the streets and takes contaminants into stormwater wells. From stormwater pipes, water is led to lakes and the sea. The Water Authorities had as a goal that the stormwater would be of satisfactorily ecological and chemical status until year 2015, or in exceptional case a little later. It is then even more important to purify the water, which can be done through vegetation and infiltration in soils and in openwater systems. Openwater systems have better capacity to receive larger flows of water than stormwater pipes. Increased rainwater flows will happen more often with the warmer climate and the increased rainfall that comes with climate change. It is a common problem that urban stormwater pipelines are overloaded and stormwater wells and streets overflow. This report evaluates an industrial area that is planned to be converted into residential areas, for which open-stormwater systems that can be used. Today the stormwater flows from the soil sealed areas from the industrial area down to the recipient without cleaning. An efficient alternative is to use stormwater systems that have vegetation and infiltration for stormwater, so the stormwater can be purified and retarded before it reaches the stormwater pipeline. / Idag är dagvatten ett växande problem och är ett hett ämne att diskutera. På grund av urbaniseringen med växande städer och hårdgjorda ytor, rinner regnvatten av från gator och tar med sig eventuella föroreningar ner i dagvattenbrunnar. Från dagvattenledningarna leds vattnet ut till sjöar och hav. Vattenmyndigheten hade som mål att ytvattnet skulle vara av god ekologisk och kemisk status till år 2015, med undantagsfall något senare. Därav ännu viktigare att rena dagvattnet, vilket kan göras genom vegetation och infiltrering i mark och i öppna dagvattensystem. Öppna dagvattensystem har bättre kapacitet att ta emot större flöden av vatten än ordinära dagvattenledningar. Ökade dagvattenflöden kommer att ske oftare med det varmare klimatet och den ökade nederbörd som kommer med klimatförändringarna. Det är ett vanligt problem att dagvattenledningarna i städer blir överbelastade och dagvattenbrunnar och gator svämmar över. I denna rapport utvärderas ett industriområde som planeras att byggas om till bostadsområde, för vilka öppna dagvattensystem som kan användas. I dagsläget rinner dagvattnet från de hårdgjorda ytorna från industriområdet ner till recipienten utan rening. Ett bra alternativ är att använda dagvattensystem som har vegetation och infiltrering för dagvatten, då kan dagvattnet både renas och fördröjas innan det når dagvattenledningen.
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A performance investigation of stormwater accommodations in Stockholm : A multi-criteria decision analysis / Utvärdering av prestandan hos dagvattensystem i Stockholm : En multikriterieanalysJonsson, Martin January 2017 (has links)
Stormwater management is a problematic area and has during the last 20 years been given an increased attention due to more pollution in the cities. The increased pollution and contaminants in stormwater implicates risks for animals, humans, the ecosystem and receiving recipients. Due to the increased attention, authorities, government and other stakeholders have developed measurements to deal with the problem. Stormwater accommodations and other type of stormwater detainment has been developed with increased modern technology and functionality to fit specific areas where different type of pollutants can vary. Stormwater treatment are necessary because it creates social, environmental and technical advantages combined with protection of ecosystem, increased multifunctionality when combining for example stormwater ponds in nature, parks or urban and rural environment. This report describes seven diverse types of stormwater accommodations systems; rain garden, stormwater ponds, wells, screen basins, infiltration trenches, pipe-/concrete magazine and swales in accordance from Structor Mark Stockholm. From these seven accommodations, three were chosen to be included in Multi Criteria Decision Analysis (MCDA). The purpose of the MCDA was to evaluate four different categories linked to stormwater, which are environment, social, technology and economical categories. These categories are broad concepts; therefore, parameters were developed to narrow down the areas within the concept, from which the area of investigation was founded within. The parameters created for each category are degree of purification for the environmental category, performance and maintenance for the technological category, aesthetical and social benefits for the social category and costs and risk for the economical category. The criteria developed from these parameters are specific topics that was scored from the scale between 0-5, where 0 = insignificant, 1= Low, 2= Moderate, 3= Major, 4=High, 5= Very high. A reference option was also created, considered as “no commercial treatment of stormwater”, only to transport stormwater. This reference option was also referred to as a zero-alternative and is drainage by piping. The scoring was conducted by stakeholders and citizens of Stockholm. The scoring of the three chosen stormwater accommodations and the reference alternative after calculating the mean value and summarize it resulted in that stormwater pond received the highest overall score of 11.9 followed by rain gardens 11.4, infiltration trench 11.3 and drainage by piping 7.3. The stakeholders are influential people that works either with stormwater, layout and planning or maintenance personnel. Citizens of Stockholm provided inputs only in regards of the social aspects. A total of 20 stakeholders were contacted and 5 stakeholders participated in the scoring procedure. Citizens were interviewed on the street; a total of 60 people was asked to participate and 13 people decided to participate in the scoring procedure of the social aspects. Although, the attendance of stakeholders was low, they are still considered important to this project since they provided the scoring of the criteria for each respective category (environment, technology, social and economic). In regards of the low attendance by stakeholders, this resulted in a way that it became hard to distinguish the result between the different stormwater accommodation. Therefore, it was hard to determine which stormwater accommodation that was the best out ofthe ranking provided by the MCDA. A benefit by using MCDA as a tool in this case, gave an indication that the MCDA can work as a framework to decision makers, even though the result in this case became difficult to manage and distinguish between the different stormwater accommodations. Finally, the method, layout and analysis itself can provide means of measurements for stormwater investigations when the purpose is to choose between the best stormwater systems included in the MCDA. Inputs from stakeholders concluded that depending on what type of existing circumstances, there must be a site-specific evaluation to treat every area as a unique area, before deciding what type of stormwater accommodation to apply to that specific location. / Dagvattenhantering är ett problematiskt område som under de senaste 20 åren har fått allt mer uppmärksamhet då mer föroreningar uppdagats i städerna. Den ökande föroreningen av dagvatten tenderar att orsaka en större risk för djur, människor, ekosystem och recipienter dit dagvatten rinner. På grund av uppmärksamheten som dagvattenhanteringen har fått, har myndigheter, regering och andra intressenter utvecklat dagvatten teknologin ytterligare för att skapa en modern dagvattenstrategi för att handskas med problemet. Dagvattenhantering är nödvändigt eftersom den skapar sociala, miljömässiga och tekniska fördelar samt om dagvattensystemen kombineras med funktionalitet så kan detta ge ökat skydd för ekosystemen samt förbättrad hälsa hos befolkningen i städerna. Den här rapporten beskriver sju olika typer av dagvattensystem så som; rain gardens, dagvattendammar, brunnar, skärmbassänger, svackdiken, rör-/betong magasin samt krossdiken på begäran av Structor Mark Stockholm. Utav dessa 7 dagvattensystem, ingick 3 anläggningar i en så kallad multi-criteria decision analysis (MCDA). Syftet med en MCDA är att utvärdera fyra olika kategorier som kan förknippas med dagvattenhantering. Kategorierna är miljömässiga, sociala, tekniska och ekonomiska. Dessa kategorier utger dock ett brett budskap och för att begränsa analysen så skapades parametrar. Dessa parametrar skapas utifrån varje enskild kategori. För den miljömässiga kategorin skapades parametern grad av rening, för den tekniska kategorin skapades parametern prestanda och underhåll, för den sociala kategorin skapades parametern estetiska och sociala fördelar, och slutligen för den ekonomiska kategorin skapades parametern kostnader och risker. Utifrån dessa parametrar skapades sedan kriterier med specifika huvudämnen som kan bedömas enligt en poängskala från 0-5 där 0 = insignificant, 1=Low, 2= Moderate, 3= Major, 4= High, 5= Very high. Tre dagvattensystem inkluderas i MCDA vilket var; rain gardens, dagvattendammar, krossdiken vars syfte är att rena och fördröja dagvatten. Ett referensalternativ skapades också som ävenkallas ”zero-alternative”, vilket anses inte ha någon rening av dagvatten utan är endast ett transportsystem för dagvatten. Detta referensalternativ kallas drainage by piping. Poängsättningen gjordes av intressenter och invånare i Stockholm. Intressenterna är människor som arbetar med dagvattenhantering antingen på planeringsstadiet eller ute i fält som drift och underhålls personal. Invånare i Stockholm bedömde endast den sociala kategorin eftersom det kan sakna kunskap och insyn i det miljömässiga, tekniska och ekonomiska detaljerna. Totalt kontaktades 20 intressenter där 5 personer valde att medverka i MCDA. Invånare i Stockholm intervjuades på stan, totalt frågades ca 60 personer varav 13 personer valde att medverka i poängsättningen. Poängsättningen av de tre valda dagvattensystemen samt referensalternativet, efter beräkningav medelvärdet samt den totala summeringen resulterade i att dagvattendammar fick den hösta poängen 11,9 hamnade rain garden på andra plats med 11,4, krossdike på tredje plats med 11,3 samt referensalternativet på en fjärde plats med 7,3. De tre dagvattensystemen hade ett relativt liknande slutgiltigt resultat. Dock så skilde sig den individuella kategoriska bedömningen av miljömässiga, tekniska, sociala samt ekonomiska aspekten med större varierande resultat. Även om deltagandet av intressenter var relativt lågt, endast 25 % av det kontaktade intressenterna valde att ställa upp, så anses dessa intressenter vara viktiga för det här projektet då de, utifrån deras kunskap, bedömer det uppsatta kriterierna och det är denna bedömning som resultatet baseras på. Resultaten mellan det olika dagvattenanläggningarna som var inkluderade i MCDA var svåra att särskilja, troligtvis beroende på att ingen viktningsmetod användes. Däremot så är en fördel med MCDA som verktyg i det här fallet, att det gav en indikation på att MCDA kan fungera som ett stödjande verktyg för beslutsfattare även om resultatet i det här fallet var svårt att särskilja. Själva metoden, upplägget och analysen kan användas som medel för att avgöra vilken typ av dagvattenanläggning som passar bäst utifrån de kriterier som är uppsatta. Slutligen så gav intressenterna en påvisning att dagvattenanläggningar ska konstrueras så att hänsyn tas till omkringliggande omständigheter, där varje plats ska ansesvara unik. Det krävs en platsspecifik utredning där hänsyn till geologiska, geotekniska,hydrologiska samt infrastrukturella och miljömässiga aspekter bör utredas innan valet av dagvattensystem bestäms.
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Modeling Techniques and Local Strategies of Green Infrastructure Capitals to Control Urban Stormwater Runoff and Combined Sewer OverflowsAbi Aad, Maya P. 15 April 2009 (has links)
No description available.
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