No description available.

Creeks and rivers are often polluted as a result of stormwater runoff that carries various contaminants in to open water bodies, causing adverse environmental and health effects. Low impact development (LID) techniques are currently employed to treat this runoff prior to discharge. Nitrate, however, is not consistently removed by these LID techniques. This study analyzed the ability of several nanoclays to remove nitrate in runoff and determined the feasibility of using them as a soil supplement for LID implementation. Six different nanoclays and HCl-treated clays were compared (pre-modified trimethyl stearyl ammonium nanoclay, pre-modified dimethyl dialkyl amine nanoclay, unmodified hydrophilic bentonite, unmodified halloysite nanoclay, HCl modified hydrophilic bentonite and HCL modified kaolin) to the control clay, unmodified kaolin, for their ability to adsorb nitrate solution by batch adsorption experiments. The findings determined that the pre-modified trimethyl stearyl ammonium nanoclay was the most effective adsorbent, decreasing the nitrate concentration up to 86% for a nitrate to clay ratio of 6.25 mg: 1 g under normal pH (5-6) and temperature (25⁰C) conditions. The HCl acid modification did not prove to provide significant additional benefits to the clays. Column studies were also conducted on the most successful clay, pre-modified trimethyl stearyl ammonium nanoclay, to assess the breakthrough point when 0.1% w/w and 1% w/w of the nanoclay were added to Nevada Sand. The results showed a projected breakthrough pore volume of 17 when the larger fraction was added to the sand, and a corresponding hydraulic conductivity of 12.6 in/hr, which is 35% slower than the un-amended Nevada Sand. Such a high hydraulic conductivity indicated that future work can test larger fractions of clay to sand mixtures to achieve a higher number of pore volumes before the soil reaches its breakthrough point. Future studies can also further explore both batch and column experiments to assess the feasibility of implementing soil amendments to a filtration system by changing the experimental parameters, such as base soil material, types of nanoclays used, and the nanoclay to nitrate ratios. Additionally, synthetic stormwater from runoff should be used as the influent instead of a nitrate-only solution to reflect more realistic scenarios for a potential real-world application.

Developments that have been taking place on Cal Poly campus over the years have altered the natural hydrology of the area. Stormwater management practices could help reduce the impacts of these developments. Computer models can help to design effective and economical stormwater management solutions at a watershed scale. As such, the objective of this study was to develop a stormwater management model for Cal Poly campus. The model was developed based on the utility data obtained from the university and other watershed data available from open sources. Field surveys were conducted to address some anomalies in the utility data, and streamflow monitoring was performed. The model was calibrated using the streamflow data measured during this study. The calibration effort significantly improved the prediction accuracy of the model. The calibrated model was then used to analyze the hydrologic performance of implementing LID systems for two projects that Cal Poly plans to build. Permeable Pavements (PPs) and Bioretention Cells (BRCs) were the LID types examined. The LIDs were evaluated based on peak flow and runoff volume reductions they would achieve. The potential reductions were compared for current conditions and the proposed project if LIDs were implemented, and for inflows to the LIDs and outflows from the LIDs. The results indicate that implementing a PP system for the proposed student apartment at the current H-1 and R-1 parking lots and a BRC system for the proposed engineering project facilities at the current H-2 parking lots will significantly reduce peak flow and runoff volume. Overall, the developed model will help the university with the traditional stormwater management practices such as flood control and to identify effective LID practices for future developments. Limitations of the current model and recommendations on how to improve the model are also discussed.

Stormwater sewer infrastructure is at risk due to ageing, structural deterioration, population growth, and climate change. Since the consequences of the sewer system failure can adversely impact the community safety, environment and economy, a resilient infrastructure system is of essential importance. However, limited reinvestment budget and insufficient asset management practices impact the rehabilitation of urban sewerage systems. Therefore, an effective and efficient rehabilitation plan is needed to help proper investment decisions. An effective rehabilitation plan will maximize hydraulic performance while minimizing the overall failure risk within a limited budget. The current study aims to address this issue through designing a risk-informed methodology in three steps. First, the hydraulic risk index (obtained using the SWMM model) was combined with the ageing pipe index. The framework uses multi-objective optimization technique to generate solutions under specific sewerage conditions. We named this new framework as Hydraulics and Risk Combined Model (HRCM). Several scenarios including high hydraulic risk, high ageing risk, hydraulic risk and ageing risk (combined problems), and limited budget problems, are used to test the performance of the proposed methodology. The results show that the proposed model could provide a satisfactory solution. Then, in order to increase the calculation speed and improve the accuracy, sensitivity and cost-effectiveness analyses were also conducted for the proposed methodology with different algorithms. The results show that different algorithms offer various benefits. A new calculation method was offered by combining the advantages of the previous methods. Finally, a new optimization method named Phenotype Searching Method, which was enlightened by sexual selection processes, was offered. This method can enhance the selection processes to specific phenotypes (pipes) so that it can increase the convergence speed and increase the performance of the HRCM model.

Vattenbehovet stiger i världen till följd av ökande befolkning. Med ökad urbaniseringskapas mer hårdgjorda ytor där föreningar ackumuleras. Dagvattnet transporterar dessa föroreningar som således kan nå grundvattnet. Ett miljömål har antagits i Sverigeför att skydda grundvattentäkter och därmed säkra framtida dricksvattenförsörjning. Rullstensåsar innehåller stora grundvattenmagasin och har hög infiltrationsförmåga för vatten från markytan. Uppsala kommun tar 95 % av sitt dricksvatten från rullstensåsenUppsalaåsen. Ulleråker ligger strax söder om Uppsala stadskärna och i området planerasen ny hållbar stadsdel. Stadsdelen ligger delvis rakt på Uppsalaåsens kärna och det ärviktigt att inget förorenat dagvatten kan infiltrera åsen då det kan påverka dricksvattenförsörjningennegativt. Syftet med detta projekt är att bidra till en djupare förståelse för hur grundvattnet kan påverkas av dagvattenhanteringen vid den planerade nybyggnationen av Ulleråker. Målet med projektet är att utvärdera vad hållbar dagvattenhantering innebär och hur tekniken är planerad att implementeras i Ulleråker. Projektet innefattar även utvärderingav alternativa tekniker som applicerats i andra stadsbyggnadsprojekt med hållbarhetsprofil som skulle kunna tillämpas i Ulleråker. Projektet är till största delen en litteraturstudie där planprogram för Ulleråker studeratsför att identifiera och utvärdera risker som kan uppstå till följd av dagvattenhanteringen,men även för att utvärdera de åtgärder som planeras. En modellering utfördesäven för att studera föroreningsspridning från en bilväg i området. Slutligen studeradesandra stadsbyggnadsprojekt för att se om deras lösningar skulle kunna implementeras i Ulleråker. De främsta riskerna för grundvattenkvaliteten relaterade till dagvattenhantering i Ulleråker har identifierats till släckvatten vid brand, dagvatten- och avloppsledningarsamt utsläpp under byggnationen. Planerade åtgärder är att utifrån sårbarhetsområdensätta restriktioner för markanvändningen och hur byggnationen ska gå till, särskilt vidåskärnan. Dagvattenhantering ska utgå från ett robust dagvattensystem baserat på ettsystemtänk genom att inget dagvatten ska infiltrera marken i sårbara områden. Detta ska säkerställas genom ett tätt vattenledningssystem som avleder dagvattnet till dagvattendammardär det fördröjs och renas. Hantering av släckvatten vid bränder ska ske genom att täta markytor kring byggnader hindrar släckvatten från markinfiltration. Endast vatten får användas som släckvätska. Modelleringen över föroreningsspridning frånen bilväg i Ulleråker visar att föroreningar avsätts på en yta upp till 6 meter från vägbanansmitt. Ett annat stadsbyggnadsprojekt som studerades var Augustenborg i Malmödär dagvattensystemet bygger på öppna lösningar med bland annat kanaler, dammar ochgröna tak. Slutsatserna är att hållbar dagvattenhantering generellt går ut på att fördröja ochrena dagvattnet lokalt. De lösningar som tagits fram för Ulleråkers dagvattenhanteringbygger på täta ledningar och dammar som fördröjer vattnet innan det når ytvattenrecipienten Fyrisån eller kopplas på Uppsala kommuns dagvattenledningar. I Ulleråker blir det viktigt att kontrollprogram finns och efterföljs för att minska risken för förorening av grundvattnet. Föroreningar från Ulleråkersvägen sprids upp till 6 meter ut från vägensmitt och det är således viktigt att täta denna yta så att föroreningarna inte kan infiltreramed dagvattnet ner till Uppsalaåsen. Lösningar från Augustenborg som skulle kunna implementeras i Ulleråker är gröna tak med tjocka jordlager då de renar vatten mer effektivtän tak med tunnare jordlager. / Water demand rises in the world as a result of increasing population. Increased urbanizationcreates more impervious surfaces where pollutants accumulate. The stormwater transports these pollutants, which can thus reach the groundwater. An environmental goal has been adopted in Sweden to protect the groundwater and thus secure future drinking water supply. Eskers contain large groundwater storages and have high infiltration capacity for water fromthe ground surface. Uppsala municipality takes 95 % of its drinking water from the Uppsalaesker. Ulleråker is located just south of Uppsala city centre and in the area a new sustainabledistrict is planned. The district is partly located on the Uppsala esker’s core and it is importantthat no contaminated water is able to infiltrate the esker as it may affect the drinking watersupply negatively. The purpose of this project is to contribute to a deeper understanding of how the groundwatercan be affected by the stormwater management in the planned new construction of Ulleråker.The aim of the project is to evaluate what sustainable stormwater management means andhow the technology is planned to be implemented in Ulleråker. The project also includesevaluation of alternative techniques applied in other urban construction projects with sustainability profile that could be implemented in Ulleråker. The project is mainly a literature study where Ulleråker's plan program has been studied to identify and evaluate risks that may occur as a result of stormwater management, but also to evaluate the planned measures. A modelling was also conducted to study pollutant dispersio nfrom a roadway in the area. Finally, other urban construction projects were studied to see if their solutions could be implemented in Ulleråker. The main risks of groundwater quality related to stormwater management in Ulleråker have been identified as extinguishing water in the event of fire, stormwater and sewage pipelinesand leakage during construction. The planned measures are to impose restrictions on land usebased on vulnerability areas and how the construction is executed, especially at the core of the esker. Stormwater management should be based on a robust water system based on a system thinking so that no water will infiltrate the soil in vulnerable areas. This is to be ensured by a dense water pipeline system that leads the stormwater into surface water dams where it isdelayed and cleaned. Handling of extinguishing water should be done by sealing land surfaces around buildings preventing extinguishing water from soil infiltration. Only water may beused as extinguishing fluid. The modelling of pollution dispersion from a roadway inUlleråker shows that contaminants are deposited on a surface up to 6 meters away from the centre of the roadway. The studied urban building project Augustenborg in Malmö has its stormwater system based on open solutions, including channels, ponds and green roofs. The conclusion is that sustainable stormwater management in general is based on delayingand cleaning stormwater locally. The solutions developed for Ulleråker’s stormwatermanagement are based on dense conduits and ponds that delay the water before reaching thesurface water receptor Fyrisån or are connected to Uppsala municipality's water pipelines. In Ulleråker it becomes important that control programs are in place and followed to reduce therisk of groundwater contamination. Pollution from Ulleråkersvägen is spread up to 6 meters out of the middle of the road and it is therefore important to seal this area so that thecontaminants cannot infiltrate with the stormwater to Uppsalaåsen. Solutions from Augustenborg that could be implemented in Ulleråker are green roofs with thick soil layers asthey clean water more efficiently than roofs with thinner soil layers.

No description available.

No description available.

The environmental issues of storm water in the urban environment is addressed in political policies on many different governance levels. The concept of “sustainable storm water” in Europe uses the natural water cycle as a template for urban drainage, and the EU has a water framework directive (WFD) with a systems approach, using drainage basins as the starting point of all actions. In Stockholm, a new storm water strategy was adopted in 2015 with a sustainability approach, using much of the terminology from the WFD and the Swedish Water & Wastewater Association. To find new aspects related to sustainable development of storm water management in Stockholm, this study used a resilience framework of seven principles to analyse the implementation of the Stockholm storm water strategy (SSWS). A mixed method approach was used for a qualitative study, using interviews and a review of policy documentation as the main data sources, complemented by a desk study of literature on the subject of storm water management, as well as participation in some relevant workshops. To broaden the study, examples from a developing area within the Stockholm municipality, Stora Sköndal, was used, as well as another municipality in the Baltic Sea region; Helsinki (Finland). The SSWS leans on the legislation of the environmental quality standards (EQS) but is lacking in authority coordination on a national and municipal level in Stockholm. Diversity in problem formulations and solutions for infrastructure is high, so is the diversity of involved stakeholders, which is an indication of resilience. This in combination with the structure and communicational links having questionable functionality, leads to a complex and inefficient structure in management of storm water, which undermines the resilience of the system. However, since the SSWS and other connected policies (such as local programmes of measures and sustainability requirements) are new, the system is undergoing change, which shows some level of adaptability and complex adaptive systems (CAS) thinking, another resilience indicator. The implementation of the WFD on a municipal level is also connected to CAS thinking, as well as a polycentric governance system -one of the seven resilience principles of the framework used. Some of the main issues found within this study for building resilience in the SES are related to follow-up and responsibility division. / Miljöfrågor inom dagvatten hanteras i policyarbete på flera olika institutionella nivåer. Begreppet ”hållbart dagvatten” utgår i Europa från den naturliga vattencykeln och EU:s vattendirektiv (WFD) har en systeminriktning som utgår från avrinningsområden istället för andra geografiska gränsdragningar. Stockholms Stad antog en ny dagvattenstrategi 2015 med en hållbarhetsinriktning, som innehåller mycket terminologi från WFD och publikationer från branchorganisationen Svenskt Vatten AB. För att hitta nya aspekter för en hållbar utveckling av dagvattenhantering i Stockholm använder denna studie ett teoretiskt ramverk inom resiliens,, som bygger på sju principer, i en analys av stadens dagvattensstrategi (SSWS). Blandade metoder användes för att genomföra en kvalitativ studie, där policydokument granskades tillsammans med intervjuer av nyckelpersoner, vilket kompletterades med en skrivbordsstudie av litteratur om dagvattenhantering samt deltagande i relevanta workshops. För att bredda studien användes exempel från ett planprogramsområde inom Stockholms kommun, Stora Sköndal, liksom en annan kommun i Östersjöområdet; Helsingfors (Finland). SSWS bygger juridiskt på miljökvalitetsnormerna, men brister i myndighetssamordning på nationell och kommunal nivå i Stockholm. Problemformuleringar och infrastrukturlösningar har hög mångfald, precis som involverade aktörer, vilket är en indikation på att systemet bygger upp resiliens. Detta i kombination med att struktur och kommunikationslänkar är något bristfälliga leder till en komplex och ineffektiv dagvattenhantering, vilket underminerar resiliensen i systemet. Eftersom SSWS och andra relaterade styrdokument (t.ex. lokala åtgärdsprogram och hållbarhetskrav) är nya, genomgår systemet förändringar, vilket visar på anpassningsförmåga och komplext, adaptivt systemtänk (CAS), vilket är en ytterligare resiliensindikator. Implementeringen av WFD på kommunal nivå är också kopplad till CAS-tänkande, liksom ett polycentriskt styrsystem - en av de sju principerna för resiliens i det teoretiska ramverket som används. Några av de huvudsakliga problem för att bygga resiliens som hittades i denna studie är relaterade till uppföljning och ansvarsfördelning.

Vattenhantering i infrastrukturprojekt är ett viktigt ämne eftersom det kan påverka den omgivande miljön på ett negativt sätt. I projekt med förorenat mark kan vattnet innehålla allt från metaller till polyaromatiska kolväten, vilket medför svårigheter att hantera. Vattenföroreningarna orsakas av utgrävning, grundläggning, injektering, betonggjutning och bergsprängning. Vattnet kan delvis bildas av regnvatten som faller på byggarbetsplatsen eller genom schaktning under grundvattennivån. Det vatten som genom pumpning avleds från en arbetsplats eller uppfodras är känt som länsvatten. Syftet med detta examensarbete är att undersöka hur urvalet och tillämpningen av metoder för länsvatten kan förenklas och optimeras för att passa svenska förhållanden. Vidare är syftet att utvärdera hur informationen om olika tekniker är relaterad till hur entreprenörer arbetar i praktiken under vissa förhållanden. Avhandlingen består av tre delar. Den första delen är en teoretisk beskrivning av svenska lagar och utsläppskrav som gäller för länsvatten, vanliga reningsmetoder som används och hantering av länsvatten i Washington. Den andra delen är en fallstudie med ett studiebesök på byggarbetsplatsen Marieholmförbindelsen. Den tredje delen består av analytiska beräkningar och jämförelser mot provdata. Resultaten visar att vanliga container behållare bör endast användas för sedimentering av sandpartiklar eftersom ytområdet är begränsat vilket ger en kortare sedimenteringstid. De har också en begränsad flödeskapacitet vilket måste tas till hänsyn för att få en effektiv sedimentering. Specifika krav på övervakning och underhåll av container behållare bör finnas för entreprenören. I fall med mindre partiklar som till exempel silt bör användning av container behållare uteslutas, förutom vid användnings som försedimenteringssteg. Resultaten visar även att vid sedimentering av partiklar mindre än medelsilt är det nödvändigt med en uppehållstid på minst 10 timmar. Uppehållstiden kan däremot skilja sig från 10 timmar till allt uppemot 100 timmar för till exempel fin silt, som har en partikelstorlek mellan 0,0063 mm-0,002 mm. För lera skulle detta innebära en uppehållstid på minst 100 timmar vilket motsvarar mer än 4 dagar. Genom att använda traditionell sedimentering som reningsteknik skulle man antingen behöva ett stort sedimentationsområde eller ett mycket lågt flöde. Detta innebär att traditionell sedimentering är orimlig att använda sig av på grund av ekonomiska aspekter, rymdbegränsningar och effektivitet. Baserad på resultat och slutsatser, föreslås följande rekommendationer: •Vanliga container behållare som kräver hög underhållning och övervakning, rekommenderas inte att användas i större utsträckning än som ett försedimenteringssteg för partiklar som är mindre än grovsilt som har en partikeldiameter mellan 0,02-0,063 mm. •Det är viktigt att ha en helhetssyn genom att skapa tydliga riktlinjer för entreprenörerna. •Det är lämpligt att använda den hydrauliska effekten, A, för att säkerställa en korrekt konfiguration och god separationskapacitet. / Water management in infrastructure projects is an important topic since it could affect the surrounding environment in a negative way. In projects with contaminated land, the water could contain everything from metals to polyaromatic hydrocarbons which entails difficulties in managing. The water can be formed partly by rainwater that falls on the construction site or by excavation below the water level. The water pollution is caused by excavation, foundation, grouting, concrete castings and rock blasting. This water is known as stormwater discharges from construction activities. The aim of the thesis is to investigate how the selection and application of methods for stormwater management from construction activities can be simplified and optimized in order to suit Swedish conditions. Further the aim is to evaluate how the information available about different techniques relates to how the contractors work in practice under some conditions. The thesis consists of three parts. The first part theoretical description of Swedish laws and requirements dealing with stormwater discharge from construction activities, common purification methods that are used and management of stormwater discharge in the state Washington. The second part is a case study with a study visit at the construction site of Marieholmförbindelsen. The third part consists of analytical calculations and comparisons to measured data. The results show that regular containers should only be used to sediment sand particles since the surface area is limited which gives a reduced sedimentation time. They also have a limited flow capacity, which must be followed to work properly. The requirement of self-monitoring and maintenance for the contractor should be increased. In other cases, with smaller particles to settle such as silt, regular containers should not be used greater than as a pre-sedimentation step. The results also show that for sedimentation of particles smaller than medium silt it is necessary with a residence time of minimum 10 hours. This means that for the soil type fine silt, which has a particle range between 0.0063mm-0.002mm, the residence time can differs between 10-100 hours. For the soil type clay this would mean a residence time of at least 100 hours which equals more than 4 days. By using traditional sedimentation as purification technique one would either need a huge sedimentation area or a very small flow. Either of these solutions is unreasonable due to economic aspects, space limitations and efficiency. Based on the results and conclusions, the following recommendations can be proposed: •Regular containers demands a high maintenance and self-monitoring, and isn’t recommended to use in greater occurrence than as a pre-sedimentation step for particles smaller than course silt, which has a particle diameter between 0.02-0.063mm. •Use a holistic approach by creating clear guidelines for the contractors. •Use the hydraulic efficiency, λ, to ensure a proper configuration and a good separation capacity.

Construction sites are frequently cited as major sources of pollution that degrade the quality of surface water. The highly erodible topsoil is transported off site by stormwater runoff causing negative effects downstream. Research has shown that the small particles, which are the most susceptible to erosive forces, have more pollutants associated with them than larger soil particles. Currently, in the state of Florida, it is not permissible to discharge water to a receiving water body if the turbidity is more than 29 Nephelometric Turbidity Units (NTUs) above background or higher than background for an outstanding Florida water body. The removal of fine suspended sediment from water can be achieved by filtration, settling, and the use of chemical coagulants. Polyacrylamide (PAM), a coagulant, has been shown to be effective in removing fine suspended particles from water via coagulation and flocculation. The Stormwater Management Academy at the University of Central Florida has researched the use of PAM and collection mats in a treatment channel to meet state discharge requirements. In this study, turbid water using sediment from typical Florida soils was simulated and passed through a channel. The channel contained polymer blocks in a configuration previously determined to be the most effective. An important component of the treatment system is the floc collection. This research examined three types of collection mats, namely jute, coconut fiber and polypropylene mix to collect the flocs. This thesis presents the results of this investigation. The results for the sandy soil tests showed an average removal efficiency prior to the collection mat starting at 71% and decreasing to 44% at the end of the tests. The 20-foot coconut mat maintained an average removal efficiency of 90%. The turbidity due to silty-sandy soil was decreased with an average removal efficiency prior to the collection mat ranging from 50% to 65%. The average removal efficiency for the 20-foot coconut mat started at 85%and decreased to 60% during the tests. The turbidity due to crushed limestone showed an average removal efficiency prior to the collection mat ranging from 81% down to 69% over time. The average results from the 20-foot coconut mat ranged from 65% to 80%. Turbidity was tested on the samples under two conditions, a 30 second settling time and completely mixed. Statistical results show a significant decrease (?=0.05) in turbidity between the mixed and settled samples. Statistical analyses were performed on the collected data, which concluded that the capability of the mat to reduce turbidity can be repeated with a 95% confidence interval. The 20-foot length coconut mat had the highest turbidity removal efficiency for every soil type examined. Further statistical analysis showed that the achieved turbidity reduction was significantly different (?=0.05) for the various materials. It was observed that generally, each type of mat clogged during testing indicating that longer collection mats be used, possibly lining the entire channel. Recommendations from this study are to provide a settling area after the collection mats and line the entire length of the channel with the collection mat selected.