Dissertations / Theses on the topic 'Water and Sewer Systems'

La gestion en temps réel (GTR) est considérée comme une solution économiquement efficace pour réduire les déversements par temps de pluie car elle optimise la capacité disponible des réseaux d'assainissement. La GTR permet d'éviter la construction de volumes de rétention supplémentaires, d'augmenter l'adaptabilité du réseau aux changements de politiques de gestion de l'eau et surtout d'atténuer l'impact environnemental des déversoirs d'orage. À la suite de l'intérêt croissant pour la GTR fondée sur la qualité de l'eau (QBR), cette thèse démontre une stratégie simple et efficace pour les charges polluantes déversées par temps de pluie. La performance de la stratégie QBR, basée sur la prédiction des courbes masse-volume (MV), est évaluée par comparaison avec une stratégie typique de GTR à base hydraulique (HBR). Une étude de validation de principe est d'abord réalisée sur un petit bassin versant de 205 ha pour tester le nouveau concept de QBR en utilisant 31 événements pluvieux sur une période de deux ans. Par rapport à HBR, QBR offre une réduction des charges déversées pour plus d'un tiers des événements, avec des réductions de 3 à 43 %. La stratégie QBR est ensuite mise en oeuvre sur le bassin versant de Louis Fargue (7700 ha) à Bordeaux, France et comparée à nouveau à la stratégie HBR. En implémentant QBR sur 19 événements pluvieux sur 15 mois, ses performances sont constantes et apportent des avantages précieux par rapport à HBR, 17 des 19 événements ayant une réduction de charge variant entre 6 et 28.8 %. La thèse évalue en outre l'impact de l'incertitude de prédiction de la courbe MV (due à l'incertitude de prédiction du modèle) sur la performance de la stratégie QBR, en utilisant un événement pluvieux représentatif. La marge d'incertitude qui en résulte est faible. En outre, l'étude de sensibilité montre que le choix de la stratégie QBR ou HBR doit tenir compte des dimensions réelles des bassins et de leur emplacement sur le bassin versant<br>Real time control (RTC) is considered as a cost-efficient solution for combined sewer overflow (CSO) reduction as it optimises the available capacity of sewer networks. RTC helps to prevent the need for construction of additional retention volumes, increases the network adaptability to changes in water management policies, and above all alleviates the environmental impact of CSOs. Following increasing interest in water quality-based RTC (QBR), this thesis demonstrates a simple and nothing-to-lose QBR strategy to reduce the amount of CSO loads during storm events. The performance of the QBR strategy, based on Mass-Volume (MV) curves prediction, is evaluated by comparison to a typical hydraulics-based RTC (HBR) strategy. A proof-of-concept study is first performed on a small catchment of 205 ha to test the new QBR concept using 31 storm events during a two-year period. Compared to HBR, QBR delivers CSO load reduction for more than one third of the events, with reduction values from 3 to 43 %. The QBR strategy is then implemented on the Louis Fargue catchment (7700 ha) in Bordeaux, France and similarly compared with the HBR strategy. By implementing QBR on 19 storm events over 15 months, its performance is consistent, bringing valuable benefits over HBR, with 17 out of 19 events having load reduction varying between 6 and 28.8 %. The thesis further evaluates the impact of MV curve prediction uncertainty (due to model prediction uncertainty) on the performance of the QBR strategy, using a representative storm event. The resulting range of uncertainty is limited. Besides, results of the sensitivity study show that the choice of the QBR or HBR strategy should take into account the current tank volumes and their locations within the catchment

When designing urban water systems (i.e. water distribution and sewer systems) it is imperative that uncertainty is taken into consideration. However, this is a challenging problem due to the inherent uncertainty associated with both system loading requirements and the potential for physical components failure. It is therefore desirable to improve the reliability of each system in order to account for these uncertainties. Although it is possible to directly evaluate the reliability of a water distribution systems (WDS) (using reliability measures), the calculation processes involved are computationally intensive and therefore unsuitable for some state-of-the-art, iterative design approaches (such as optimisation). Consequently, interest has recently grown in the use of reliability indicators, which are simpler and faster to evaluate than conventional direct reliability methods. In this thesis, a novel measure (the RUF) is developed to quantify reliability in urban water systems with a view to enhance their robustness under a range of future scenarios (Policy Reform, Market Forces, Fortress World and New-Sustainability Paradigm). The considered four future scenarios were synthesized in the EPSRC supported multidisciplinary 4 year project: Urban Futures. Each investigated urban future scenario is characterised by a distinct household water demand and local demand distribution (emerging due to different urban forms evolving in future scenarios). In order to assess the impact of urban futures, RUF has been incorporated into Urban Water System (UWS) dynamic simulations for both WDSs and Foul Sewer Systems (FSSs) using open source codes of EPANET and SWMM. Additionally, in order to overcome extensive computational effort, resulting from the use of traditional reliability measures, a new holistic reliability indicator, the hydraulic power entropy (IHPE) has been developed and compared to existing reliability indicators. Additionally, the relationship between the new reliability indicator and the above mentioned RUF reliability measure is investigated. Results suggest that the magnitude of the IHPE in network solutions provides a holistic indication of the hydraulic performance and reliability for a WDS. However, the performance of optimal solutions under some Urban Futures indicates that additional design interventions are required in order to achieve desired future operation. This thesis also proposes a new holistic foul sewer system (FSS) reliability indicator (the IFSR). The IFSR represents sewer performance as a function of excess pipe capacity (in terms of available increase and also decrease in inflow). The indicator has been tested for two case studies (i.e. different sewer network layouts). Results suggest that the magnitude of IFSR has positive correlations with a number of identified key performance indicators (i.e. relating to capacity, velocity, blockages). Finally, an Integrated Design Approach (IDA) has been developed in order to assess the implications of applying design interventions on both a WDS and downstream FSS. The approach holistically considers present and future operation of each interconnected system. The approach was subsequently demonstrated using two proposed design interventions. Results suggest that, for the considered design interventions, there is trade-off between the simultaneous improvement of both WDS and FSS operation and reliability.

The overarching goal of this research is to establish a successful forum for a transition from the existing paradigm of managing wastewater infrastructure to a more sustainable paradigm that achieves a more efficient utilisation of wastewater assets. A transitioning approach to support a more efficient utilisation of surface water and wastewater assets and infrastructure is proposed and developed. The determined transitioning approach possesses key stages namely developing the arena, developing the agenda, case study, and monitoring. The case study stage investigates a drainage utility identifying their improvement drivers, the removal of surface water through detailed drainage modelling and the financial examination of the costs incurred under the various scenarios conducted. Understanding the implications of removing/attenuating surface water from the network is improved through obtaining data by detailed drainage modelling. Infoworks software is used to investigate and assess the current and future operational scenarios of a wastewater system operating over one calendar year. Modelling scenarios were conducted removing surface water from selected areas focusing on the volumes requiring pumping and durations of pumping station(s) operation prior to treatment during storm conditions. The financial implication of removing surface water in combined sewer systems is examined in three main components. Firstly the costs of electricity incurred at the single sewage pumping station (SPS) investigated during the various scenarios modelled require to be addressed. Secondly the costs to retrofit sustainable urban drainage system (SUDS) solutions needs to be identified. Thirdly the implications of removing surface water for the drainage utility at the national level and the potential saving for householder’s committing to a surface water disconnection rebate scheme. When addressed at the macro level i.e., with over 2,100 pumping stations, some operating in sequence and contained within one drainage utility annually treating 315,360 megalitres the significance of the same multiple quantifiable and intangible benefits becomes amplified. The research aims, objectives and findings are presented to the identified and convened stakeholders. The transitioning approach developed encourages positive discourse between stakeholders. The level of success of the transitioning approach determined is then tested using a quantitative methodology through the completion of questionnaires. From the questionnaires completed the respondents unanimously agreed that surface water flows should be removed as well as reduced from the combined sewer system. The respondents agreed that the removal of surface water from a typical combined sewer system is justified by applying a transitioning approach focusing on the energy consumption required to pump increased volumes during storm events. This response is significant based upon the economic evidence and is contrary to the respondents previous position that finance was their most influencing factor. When provided with other potentially available benefits the respondents were even more supportive of the justification to remove surface water from the combined sewer system. The combined findings of the work presented in this thesis provide further justification that the transitioning approach applied to the removal of surface water from a typical combined sewer system, as determined in this research has been successful.

Urban waste water collecting systems are designed to convey domestic, industrial and storm water. When sizing sewer network, heavy rainfall must be considered to provide the needed hydraulic capacity for collection. Maintenance is also required in order to avoid anomalies such as inflow, infiltration and unusual polluted discharges from Combined Sewer Overflows (CSOs). Inflow and infiltration decrease the treatment yield at the Waste water Treatment Plant (WWTP) and participate in hydraulic overloads and overflows. CSOs have a direct impact on the pollution of water bodies and must be strictly sized and monitored. Detecting sizing and maintenance anomalies is crucial to ensure public health and a good status of our natural environment. Today, numerical hydraulic models support consulting engineers in assessing overflows then in choosing the best technical and cost-effective scenario. The objectives of this paper are to review the dysfunctions of collecting system and to understand how a numerical hydraulic model is constructed, calibrated and then used to establish a Corrective Action Plan (CAP). My master thesis is based on a working project achieved at SAFEGE (Group SUEZ Environnement) in the Urban Hydraulics Department in Lyon (Rhône-Alpes, France) between September 2013 and February 2014. The paper will present some outcomes obtained from an Urban Hydraulic Project at Chazelles-sur-Lyon (Rhône-Alpes, France) in the South West of Lyon. Mike Urban is the software - developed by the company DHI Water- used for the numerical hydraulic modeling.

La modélisation intégrée du système d’assainissement urbain offre la flexibilité nécessaire pour développer des solutions qui bénéficient le plus au système global, en mettant l'accent sur la quantité et la qualité de l'eau, Les modèles intégrés offrent des avantages par rapport aux modèles traditionnels des sous-systèmes individuels en facilitant l’analyse efficace des interactions entre ces différents systèmes individuels (c.-à-d. les bassins versants, les égouts, les stations d’épuration et les eaux réceptrices) dans une seule plateforme de modélisation. La complexité réduite de ce type de modèle diminue le fardeau de calcul par rapport à leurs homologues détaillés, ce qui permet une plus large gamme d'évaluations telles que l'analyse de scénarios, l'optimisation par contrôle en temps réel et l’analyse d'incertitude par approche Monte Carlo. Le potentiel de créer ces types de modèles intégrés représentatifs a été démontré dans de multiples études, mais les méthodes existantes pour développer ces modèles ne sont pas bien établies ni bien documentées et nécessitent donc un grand effort pour chaque nouveau cas d’étude. De plus, l'absence d'une méthode standardisée pour représenter la partie du modèle qui simule la quantité d'eau limite l'application de ces modèles pour des études de qualité de l'eau. Bien que la recherche soit nécessaire pour développer et optimiser toutes les méthodologies impliquées dans le développement de modèles intégrés de systèmes d'eaux usées urbaines, ce projet se concentre sur les modèles conceptuels simplifiés des bassins versants et des égouts pour la quantité d'eau. L'objectif de cette étude était de développer une procédure structurée pour traduire des modèles hydrologiques et hydrauliques détaillés en modèles conceptuels simplifiés utilisés dans la modélisation du système intégré des eaux usées urbaines. L'objectif était d'améliorer la répétabilité, la flexibilité et l'efficacité de l'approche générale, indépendamment de la plateforme de modélisation choisie. Cette tâche a été réalisée en extrayant les principales étapes et considérations tout en construisant deux modèles conceptuels simplifiés d'une étude de cas au centre d'Ottawa, au Canada. La partie urbaine centrale (6 400 ha) d'un modèle détaillé PCSWMM de la Ville d'Ottawa, contenant une combinaison d'égouts séparés, partiellement séparés et combinés, a été utilisée comme modèle de référence dans cette étude de cas. La tâche principale consistait à déterminer comment traduire ce modèle détaillé en modèle conceptuel simplifié de manière structurée, systématique et répétable en utilisant WEST comme plateforme. La procédure développée suit une séquence similaire à celle des protocoles examinés dans la revue de la littérature, tout en tenant compte des spécificités liées à l'agrégation des bassins versants et des égouts. Les quatre phases principales sont la définition du projet, le développement du modèle, la calibration et la validation. Deux versions du modèle conceptuel ont été créées : le premier a d'abord été créé avec un certain niveau d'agrégation, tandis que le deuxième était plus agrégé que le premier modèle, avec environ la moitié du nombre de bloques et de réservoirs. Les deux modèles ont été calibrés et comparés au modèle détaillé. Les résultats des simulations ont montré que le volume total et la dynamique des débits calculés par les modèles conceptuels ont bien émulé ceux du modèle détaillé (&lt; &lt; 10% de différence), tout en fournissant une réduction significative du temps de calcul (10 à 80 fois). La réduction du temps de simulation pour le modèle le plus agrégé n'était pas équivalente au niveau d'agrégation augmentée, principalement parce qu’il y a une quantité de code qui est présente dans les deux codes et prend donc le même temps de calcul. Comme généralement anticipé, des différences plus grandes, mais acceptables, ont été observées en validation. Ces différences ont été attribuées à plusieurs facteurs, tels que le manque de calibration avec des données sur une période longue, les représentations simplifiées des structures spéciales, les différences entre les mécanismes utilisés dans les modèles détaillés et conceptuels pour représenter le durée de pluie, et la configuration du code de modèle. Dans l'ensemble, la validation a été une réussite étant donné que la calibration a été effectuée à l'aide d'événements de courte durée alors que la validation a utilisé une longue série de données. En général, la procédure conçue a permis de réduire le travail manuel associé à la construction d'un modèle et à bien structurer la façon de construire des modèles conceptuels. Des connaissances pour chacune des différentes phases de modélisation ont également été acquises tout au long du processus du développement des deux modèles. Dans la phase ‹‹ Définition du projet ››, les objectifs du modèle conceptuel ont guidé la méthode de développement et de calibration du modèle. Les bassins versants et les égouts ont été délimités simultanément dans la phase de ‹‹ Développement du modèle ››, tout en tenant compte des emplacements des structures hydrauliques clés, des pluviomètres et des structures de débordement. La phase de ‹‹ Calibration ›› a permis l'avancement le plus systématique étant donné qu'un bon ordre de calibration a été défini et un ensemble limité de paramètres a été ciblé pour chacune des étapes de calibration. La phase de ‹‹ Validation ›› s'est révélée essentielle pour repérer des lacunes dans les hypothèses de base et les valeurs calibrées, afin de déterminer si le modèle est prêt à être utilisé ou doit être modifié. Une procédure efficace et structurée qui traduit les représentations des bassins versants urbains et des égouts de modèles détaillés en modèles intégrés conceptuels a été développée et appliquée avec succès à une étude de cas. Comme démontré dans ce projet, l'application de la procédure structurée mènera au développement efficace de modèles intégrés représentatifs, ce qui augmentera leur utilisation potentielle pour tester des scénarios réalistes. Pour raffiner et améliorer la procédure formulée, il est recommandé de l'appliquer à d’autres études de cas.<br>Modelling urban wastewater networks within integrated systems, focusing on both water quantity and quality, introduces flexibility to develop solutions with greatest benefit to the overall system. Integrated models provide benefits over traditional single sub-system models by facilitating efficient analysis of interactions between the individual components of urban water systems (i.e. catchments, sewers, treatment plants, and receiving waters) within a single modelling platform. The reduced complexity of this type of model decreases the computational burden compared to their detailed counterparts. This allows for a wider range of assessments such as scenario-testing, RTC optimization, and Monte Carlo uncertainty analyses. The potential to create these types of representative integrated models was proven in multiple studies, however, the current methods to develop these models are not well-established nor well documented, and therefore require significant work for each case study. Furthermore, the lack of a standardized method to represent the water quantity portion limits the wide-scale application of such models for water quality studies. Although research is required to further develop and optimize all methodologies involved with building Integrated Urban Wastewater System (IUWS) models, this project focuses on the simplified catchment and sewer conceptual models for water quantity. The objective of this study was to develop a structured procedure to translate detailed hydrologic and hydraulic models into the simplified conceptual models used in IUWS modelling. The aim was to improve repeatability, flexibility and efficiency of the general approach, regardless of chosen modelling platforms. This task was achieved by extracting the key steps and considerations while building two simplified conceptual models of a case study in central Ottawa, Canada. The central urban portion (6,400 ha) of a calibrated detailed PCSWMM model of the City of Ottawa, containing a mix of separated, partially-separated and combined sewer areas, was used as the reference model in this case study. The main task involved determining how to translate this detailed model into simplified conceptual models, using WEST as the platform, in a structured, systematic and repeatable way. The resultant developed procedure follows a similar sequence as the protocols reviewed in the literature review, while taking into consideration specifics related to aggregating catchments and sewers. The four main phases of this thesis are Project Definition, Model Development, Calibration and Validation. Two versions of the lumped model were created; the first was created with a certain level of aggregation, while the second was a further aggregation of the first model, resulting in about half the number of blocks and reservoirs. Both models were calibrated and compared to the detailed model as well as to each other. The simulation results showed that the volume and dynamics (ie. the shape of the hydrographs) of the conceptual models emulated those of the detailed model well (&lt; &lt; 10% differences), while providing a significant reduction in simulation-time speed-up (10 to 80 times faster than the detailed model). The simulation time reduction in the more aggregated model was not equivalent to the increased level of aggregation, mostly due to the fixed amount of basic calculation required in each model. As generally expected, larger but acceptable differences were found during the validation period compared to the calibration period. These differences were attributed to several factors, such as the lack of a long-time series calibration, oversimplified representations of special structures, the different mechanisms in the detailed and conceptual models used to represent wet weather flow, and the configuration of the model code. Overall, the validation was successful given the fact that the calibration was performed using events whereas the validation used an extended time series of 45 days. In general, the devised procedure helped reduce the manual labour associated with building a model and structured the approach to build the conceptual models. General findings from the various identified phases were also documented throughout the model building process. In the Project Definition phase, the conceptual model’s objectives guided the method of model development and calibration. The catchments and sewers were delineated concurrently in the Model Development phase, while taking into consideration the locations of the key hydraulic structures, raingauges and overflows. The Calibration phase allowed for the most systematic advancement of the model build, given that a good calibration order was defined and a limited set of parameters was targeted in each successive run. The Validation phase proved critical in pinpointing deficiencies in the initial assumptions and calibrated values, thus determining whether the model is ready for use or needs to be modified through one of the preceding phases. An efficient and structured procedure that translates catchment and sewer representations from detailed to conceptual models in IUWS was developed and successfully applied to a case study. As demonstrated in this project, applying the proposed structured procedure will lead to the efficient development of representative IUWS models, thus increasing their potential use to test real-life scenarios. To challenge and improve the formulated procedure, applying it to multiple case studies is recommended.

Owners of infrastructure assets have responsibility for the management of a diverse portfolio of civil engineering assets. These assets make up the foundations of modern society and are arguably pivotal in the economic growth and wellbeing of a nation. It is of no surprise therefore, that asset management business practises have risen in popularity as the UK’s infrastructure asset base continues to grow and inevitably ages with time. In the context of water and waste water infrastructure assets, which communities rely upon for health, economy and environmental sustainability, it is widely acknowledged that these assets have historically suffered from underinvestment. Whilst funding shortfalls have been evidenced historically, through the inadequacy of infrastructure to meet the needs and challenges of the past, it is of great concern that infrastructure expenditure is reducing in real terms as a result of the global financial crisis. This is leading to a widening funding gap between the available and the required finances for infrastructure investment which is further compounded by natural phenomena and human behaviours, i.e., climate change, population growth and urbanisation. To further intensify the problem, asset planning and management in the water industry is considered a complex and challenging discipline because of high interdependencies and the vast quantity of assets themselves. In acknowledgement of this global position, this thesis seeks to address some of the key challenges faced by utility companies in the adoption of asset management best practice across water and waste water assets, namely: • Operational decision making - the efficient and effective specification of least-cost rehabilitation programmes from condition information that ensure behavioural alignment with an organisations strategic objectives. • Tactical decision making - achieving risk based asset level inspection prioritisation that considers serviceability performance, for two particularly challenging asset groups: i.) High value - low volume assets and ii). Low value - high volume buried infrastructure. • Strategic decision making - identifying optimal long-term investment plans and asset management policies for assets that have previously not benefited from such technological advancements. To improve upon operational decision making, the author capitalises on the availability of condition inspection information for buried sewerage infrastructure by applying advanced optimisation techniques to help form an environment where the decision makers is presented with an array of optimal rehabilitation solutions. The trade-off curve that is presented uniquely evaluates solutions for the benefits they offer in-terms of: condition improvement, cost and operational performance. A financially favourable comparison (up to 45% saving) is drawn between the optimisation results which are automatically generated by the model and those that have been developed manually by experienced engineers in a ‘real world’ case study. However, it could be argued that the greatest benefit arises from the trade curve of feasible solutions which are presented to the decision maker across a range of investment levels. In recognition that tactical and strategic decision making have been the focus of a substantial amount of research for commonly found infrastructure assets, i.e., public sewers and water mains, a focus has been placed on improving upon and adopting best practise across infrastructure assets which have not previously benefited from the technological developments across these decision making levels. Firstly, a methodology for translating standardised condition inspection information into more meaningful reliability scores, to support risk based planning and decision making, is presented for service reservoirs. A service reservoir can be regarded as high value- low volume infrastructure asset and would typically have its condition evaluated between 1 (poor) to 5 (good). A case study demonstrates how this new reliability scoring mechanism has been successfully applied during a typical structural condition survey. The output from this process is a fully document reliability assessment for each component of the service reservoir. The output can be aggregated to provide an overall reliability assessment for the structure and/or used to target specific remedial works to troublesome components. Secondly, two methodologies are presented which address the fact that high volume – low value infrastructure assets across both the water distribution and wastewater collection networks, are typically less well understood and often sub-optimally managed in comparison to more critical or higher value assets. 1. A methodology has been developed to help UK water companies overcome the recent legislative changes associated with Section105A of the Water Act; which has transferred ownership of the private sewer network to UK water companies. The new methodology which has been developed, has allowed one of the UK’s water and sewerage companies to initiate a proactive asset management programme with the aim of addressing the deteriorating condition of these assets whilst also tackling their associated serviceability performance. Initially, a number of GIS tools are used to provide an estimate of the likely extent of the transferred network before a well-established public sewer deterioration model is used to predict the condition and operational performance of these S105A assets over time. 2. A novel deterioration modelling framework is developed by coupling the latest geospatial technologies with statistical deterioration modelling techniques. The modelling framework is specifically applied to small diameter water distribution assets (25-50mm diameter), known as communication pipes, which connect individual properties to the water distribution mains. Reliability curves are developed from failure data provided by two UK based Water Companies that have captured specific communication pipe failure records since 2001. The deterioration modelling curves and supporting data are compared and contrasted to demonstrate the robustness of this modelling approach, which is shown to be capable of modelling failure rates to a high degree of accuracy. This was validated by comparing the predicted number of failures against three years of failure data not used during the model building process. The yearly failure counts were predicted to within +/-5% accuracy and the overall cumulative modelled failure count at the end of 2014 was predicted within 1%. To conclude, the successful deterioration modelling tools for communication pipes are explored further, via the development of a strategic whole life cost optimisation framework for these assets. The outputs from the previous geospatial mapping tool are used alongside the calibrated Weibull deterioration curves to drive a whole life cost and performance analysis. Against this improved understanding of whole life costs, an optimisation algorithm is used to evaluate the trade-off between whole life costs (totex) and the prevention of future asset failures (serviceability). The model successfully identifies optimised investment policies according to the decision maker’s priorities which is evidenced in a case study that shows outperformance against existing maintenance policies for these assets. Financial savings in the region of £8.5M, or the prevention of 1,320 asset failures, were shown to be possible over a 25 years planning horizon in the case study. For the avoidance of confusion, the term ‘integrated’ is considered from the perspective of the three decision making levels associated with the management of an asset, namely: strategic, tactical and operational decision making. Therefore, data quality improvements and the management of information transactions between decisional levels are inherently considered within all of the methodologies developed in this thesis.

Diploma thesis deals with design of sanitary and gas instalation in hotel building. It is hotel with four floors and basement. Theteoretical part is focused on grey water treatment systems and possibility of their use in the building. The Computational part and project includes design of sanitary and stormwater sewer, water supply system, gas installations a their service pipes to current utility lines.

This Diploma thesis deals with design sanitation installation in a residential building in Prague. The theoretical part is aimed at determining the calculation of flow in the sup-ply duct according to standards. The work also focuses on the alternative solutions of the given specialization. The computational part and project includes a proposal sani-tary and storm sewer, water supply system and their connection to the current pipes. It is a residential building with four overground floors and with two underground floors.

Apresenta-se um estudo de caso realizado nas cidades de São Carlos e Araraquara, Estado de São Paulo, em que são analisados problemas nos pavimentos associados aos serviços de manutenção da infra-estrutura de água e esgoto, tanto em nível de rede como em nível de projeto. Investiga-se a possibilidade de compatibilização da gerência de pavimentos com a gerência de outras infra-estruturas e analisam-se as normas dos serviços, os métodos de execução efetivamente utilizados e os procedimentos de controle e garantia da qualidade. Os resultados mostram a necessidade de implementação de sistemas racionais de gerenciamento de infra-estruturas pelas prefeituras e concessionárias de serviços públicos e o desenvolvimento de regulamentações, manuais e guias para restauração dos pavimentos após os serviços de manutenção das redes, com um controle mais rigoroso dos procedimentos técnicos.<br>It is presented a case study performed in the cities of Sao Carlos and Araraquara, state of Sao Paulo, Brazil. It analyses pavement problems associated to the maintenance of water and sewer infrastructure networks at both network and project levels. It investigates the possibilities of integration of the pavement management to the management of other infrastructures and it analyses the service regulations, the construction methods effectively used and the quality control/quality assurance (QC/QA) procedures. The results show the necessity of the implementation of a rational infrastructure management system by the cities and urban agencies, and the development of regulations, manuals and guidelines for pavement restoration after the maintenance of water and sewer networks, which will allow a more effective enforcement of the technical standards.

The thesis deals with sanitary engineering and gas installation in an apartment building with a healthcare facility. The theoretical part is focused on the installation systems, which are addressed to the suitability of the system in the given project, and the advantages and disadvantages of these systems. Computational and project part addresses the sewer, water mains and gas in the specified object. Designed building is without a basement and eight storeys. On the first floor is located technical facilities around the building and three residential units. All other floors are located on each floor of four residential units. This thesis is done on the basis of current Czech and European regulations.

Den ökade mängden hårdgjorda ytor i städerna skapar en större och snabbare avrinning av dagvatten till ledningsnäten. En del av dagens befintliga ledningar klarar inte av att hantera denna ökade mängd dagvatten. En snabb och kortsiktig lösning på lösa detta problem är att anlägga fördröjningsmagasin som avlastar ledningsnäten. Fram till denna tidpunkt har det inte utförs tillräckligt med undersökningar kring de olika effekter som placeringen av ett fördröjningsmagasin medför. Ett fördröjningsmagasin som anläggs för att fördröja flödet av dagvatten från ett delområde kan, vid felplacering, ha en negativ verkan på flödet längre ner i ledningsnätet. Denna flödesreglering kan vara till nackdel för ledningsnätet eftersom det fördröjda flödet från delområdet kan samverka med flödestoppen från en annan del av området och kan skapa översvämningar. Syftet med denna rapport var att undersöka om olika placeringar av ett fördröjningsmagasin hade någon effekt på flödet i ett dagvattensystem. Målet var att finna placeringar där ett fördröjningsmagasin förhindrade en samverkan av flödestoppar och minskade antalet översvämningarna i ledningsnätet. Arbetet utfördes genom hydraulisk modellering i programmet MIKE URBAN. I programmet undersöktes två olika modeller över dagvattensystem. Resultaten ur de två modellerna visar på att placeringen av magasin i ett dagvattensystem har betydelse för hur översvämningar kan undvikas. Lägst antal översvämningar uppstod när magasinen placerades i viktiga knutpunkter på ledningsnätet. Mer tid och resurser bör läggas ner på att undersöka effekten av fördröjningsmagasinets position och dimension innan de placeras ut i dagvattensystemet. På detta sätt kan både kostnader minskas och framtida problem undvikas.<br>The increased amount of impermeable surfaces in the cities creates a larger and faster runoff of rainwater into the drainage systems. Some of today's existing pipelines are not able to handle this increased amount of storm water. A quick and short term solution to solve this problem is to construct delaying reservoirs that unburden the drainage system. Up to this point, not enough studies have been conducted on the different effects that a placement of a reservoir brings to a drainage system. If incorrectly positioned, a reservoir built for delaying the flow of storm water from a section of a drainage system can, have a negative effect on the flow further down the system. This flow regulation can be harmful to the system when the delayed flow from the section can interact with the flood peak from another section and can cause flooding. The purpose of this report was to study if different placements of a reservoir had any effect on the flow in a storm water drainage system. The aim was to find places where a reservoir could be positioned to prevent the collaboration of peak flows.  This thesis was mainly conducted with the use of the hydraulic modeling program MIKE URBAN in which studies of two models are the bases of the results presented in this report. The results from the two models show that the placement of a reservoir in a drainage system has a large sway on how to avoid flooding. The least amount of floods was attained when the reservoir was placed in certain key positions in the drainage system. More time and resources should be devoted to further investigate the effect of a reservoir’s position and dimensions before being placed into a drainage system. This way, expenditures could be reduced and simultaneously future flooding avoided.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-02-02T01:06:32Z No. of bitstreams: 1 disserta??o_Jonatan_Onis_Pessoa.pdf: 4697484 bytes, checksum: ea38c6fd7eba2bd885530337c94efbff (MD5)<br>Made available in DSpace on 2017-02-02T01:06:32Z (GMT). No. of bitstreams: 1 disserta??o_Jonatan_Onis_Pessoa.pdf: 4697484 bytes, checksum: ea38c6fd7eba2bd885530337c94efbff (MD5) Previous issue date: 2016-07-19<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES<br>Sewage systems when properly operated can help to minimize of aquatic environments degradation. In this context, this study aimed to evaluate the river water quality in towns with and without sewage. Therefore, ten towns of Bahia State were selected, seven of them containing sewage and three devoid of such services. It was used secondary data from water river quality (INEMA ? Environmental Stare Agency), sewage (SNIS). Parameters analyzed were concentration of fecal coliforms, biochemical oxygen demand, total phosphorus, dissolved oxygen and the Water Quality Index - IQA 14 points monitored in the period 2008 to 2015. Data were submitted the statistical analysis using the Kruskal-Wallis test. It was found that average AQI values ranged from 26 to 72. The four points monitored in towns without public sewage system presented classified waters as "good" while 40% of monitored points in cities with SES have waters classified as "regular 'or' bad '. Results suggest that the release of sewage into storm water systems and receiving bodies seems to be the main cause of low AQI values. Thus, there has been the weakness of the towns as the supervision of illegal sewage connections. Environmental education campaigns are recommended in order to reduce such practices and to improve water quality in rivers in these towns.<br>Os sistemas de esgotamento sanit?rio (SES), quando bem operados, s?o interven??es que podem contribuir para a minimiza??o da degrada??o de ambientes aqu?ticos. Nesse contexto, o presente trabalho teve como principal objetivo avaliar a qualidade da ?gua de rios em cidades com sistema p?blico de esgotamento sanit?rio implantado. Para tanto, foram selecionadas dez cidades do Estado da Bahia, sendo sete delas contendo SES e tr?s sem tais servi?os. Utilizou-se o registro trimestral realizado pelo INEMA da concentra??o de coliformes termotolerantes, demanda bioqu?mica de oxig?nio, f?sforo total, oxig?nio dissolvido e o ?ndice de Qualidade da ?gua - IQA de 14 pontos monitorados no per?odo compreendido entre 2008 a 2015. Os dados foram submetidos ? an?lise estat?stica, utilizando o teste de Kruskall-Wallis. Verificou-se que valores m?dios de IQA variaram entre 26 a 72. Os quatro pontos monitorados nas cidades sem sistema p?blico de esgotamento sanit?rio apresentaram ?guas classificadas como ?boa? ao passo que 40% dos pontos monitorados nas cidades com SES tiverem ?guas classificadas como ?regular? ou ?ruim?. Os resultados encontrados sugerem que o lan?amento de esgotos nos sistemas de ?guas pluviais e nos corpos receptores parece ser a principal causa dos baixos valores de IQA. Dessa forma, constata-se a fragilidade das cidades quanto ? fiscaliza??o de liga??es irregulares de esgoto. Campanhas de educa??o ambiental s?o recomendadas visando a redu??o de tais pr?ticas e a melhoraria da qualidade da ?gua nos rios das cidades avaliadas.

This thesis describes the design of plumbing in an apartment building with commercial space in Ilava. The theoretical part is devoted to the design of the container hot drinking water and it´s possible alternatives. The work also focuses on possible solutions diploma work. Computational part of a project proposal contains sewage and rainwater drainage, water supply systems and connecting the building to the existing network hardware. It is a residential house, which is in part intended for commercial premises and the second part is intended for housing. The building has four floors and no basement.

Artificial Neural Networks (ANNs) have been comprehensively researched, both from a computer scientific perspective and with regard to their use for predictive modelling in a wide variety of applications including hydrology and the environment. Yet their adoption for live, real-time systems remains on the whole sporadic and experimental. A plausible hypothesis is that this may be at least in part due to their treatment heretofore as “black boxes” that implicitly contain something that is unknown, or even unknowable. It is understandable that many of those responsible for delivering Early Warning Systems (EWS) might not wish to take the risk of implementing solutions perceived as containing unknown elements, despite the computational advantages that ANNs offer. This thesis therefore builds on existing efforts to open the box and develop tools and techniques that visualise, analyse and use ANN weights and biases especially from the viewpoint of neural pathways from inputs to outputs of feedforward networks. In so doing, it aims to demonstrate novel approaches to self-improving predictive model construction for both regression and classification problems. This includes Neural Pathway Strength Feature Selection (NPSFS), which uses ensembles of ANNs trained on differing subsets of data and analysis of the learnt weights to infer degrees of relevance of the input features and so build simplified models with reduced input feature sets. Case studies are carried out for prediction of flooding at multiple nodes in urban drainage networks located in three urban catchments in the UK, which demonstrate rapid, accurate prediction of flooding both for regression and classification. Predictive skill is shown to reduce beyond the time of concentration of each sewer node, when actual rainfall is used as input to the models. Further case studies model and predict statutory bacteria count exceedances for bathing water quality compliance at 5 beaches in Southwest England. An illustrative case study using a forest fires dataset from the UCI machine learning repository is also included. Results from these model ensembles generally exhibit improved performance, when compared with single ANN models. Also ensembles with reduced input feature sets, using NPSFS, demonstrate as good or improved performance when compared with the full feature set models. Conclusions are drawn about a new set of tools and techniques, including NPSFS and visualisation techniques for inspection of ANN weights, the adoption of which it is hoped may lead to improved confidence in the use of ANN for live real-time EWS applications.

Infiltration and inflow of non-sewer water to wastewater systems (I/I water) poses a significant problem to health, economy, and the environment by affecting the capacity of the wastewater system. To determine effective measures to reduce the amount of I/I water, it is essential to identify its most important sources. In this thesis, the relationship between leaked drinking water and I/I water was investigated by using ordinary least squares (OLS) linear regression. The first question is whether there is a statistical relationship between the amount of drinking water leakages and the amount of I/I water in wastewater treatment plants in Swedish municipalities. Data from 207 Swedish municipalities were included in the analysis. The amount of unaccounted water, i.e. the difference between produced and charged drinking water, was used as a measure of water leakage. The second question treats the feasibility of statistically comparing municipalities to determine the importance of I/I water sources. The result of the OLS linear regression shows a statistically significant relationship between the level of unaccounted water and the level of I/I water in Swedish municipalities. This could be explained by a causal process where leaked drinking water infiltrates the wastewater system. Another explanation could be simultaneous problems in the water system and the wastewater system, potentially caused by the quality of the pipelines. However, caution should be exercised when drawing conclusions from statistical comparisons between water and wastewater flows in different municipalities. Variations in other aspects such as natural conditions and infrastructure, must also be considered.

Made available in DSpace on 2016-06-02T20:00:29Z (GMT). No. of bitstreams: 1 2474.pdf: 4397371 bytes, checksum: 2de24dd78d3c917c67e2006145da6ce4 (MD5) Previous issue date: 2009-02-27<br>Water, which is needed by all living beings, is considered an economic and environmental possession of invaluable value to the life of the planet. It is found in Brazil as a possession of public domain, according to the Federal Constitution of 1988 and Law 11.445, of January 5 of 2007, which establishes the guidelines for the federal policy of sanitation. There is, therefore, the concept of ownership of management relevant to the State, with participation by the society. Wanting to demonstrate that it is possible to attain economic sustainability of a S.A.E, through the appropriate management, the case of the city of São José do Rio Preto will be studied, where the delivery of water supply and sanitation is done by a municipal authority created in August 21 of 2001, called SeMAE (Serviço Municipal Autônomo de Água e Esgoto). In the last decades it was verified, in a national territory level, trends for greater participation of private enterprises in the industry of sanitation, which contradicts the predominance, in most of the world, of public and local management. Referencing certain features of sanitation services, such as the essentiality and natural monopoly, there is a pressing need for social control. But the lacks of resources, ridiculous charges, practices of welfarism, and political interference, combined with poor management, have led to a scenario where the privatization appeared as salvation. With the introduction of National Sanitation Policy in 2007 and increased participation of the Federal Government, through the provision of programs and funding for the sector, an other reality is shown. The State, now defined as owner of sanitation services, walks in a path full of obligations and duties, in search of quality, efficiency and universal provision of the service. During the conception of this work, through the observation of the existing structures, institutional, physical, and operational of the Water and Sewer Service (W.S.S.) analysed, using data collected and carefully selected, were prepared initial diagnosis and procedures which corroborated with the evolution of this system. The comparative data used, coming mostly from the SNIS National Information of Sanitation System. The analysis and developmente of this work is permeated by the economic perspective. It avaliates, in the period from 2001 to 2008, the system of water supply and sewerage of São José do Rio Preto by means of measurable parameters and values, demonstrating its sustainability.<br>A água, necessidade de todos os seres vivos, é tida como bem econômico e ambiental de valor incalculável para a vida do planeta. Apresenta-se no Brasil como bem de domínio público, segundo a Constituição Federal de 1988 e a Lei n° 11.445, de 5 de janeiro de 2007, que estabelece as diretrizes para a política federal de saneamento básico. Têm se, portanto, a concepção da titularidade da gestão pertinente ao poder público, com participação da sociedade civil. Objetivando demonstrar que é possível atingir a sustentabilidade econômica de um Serviço de Água e Esgoto (S.A.E), por meio de gestão adequada, estudamos o caso da cidade de São José do Rio Preto, cuja prestação dos serviços de abastecimento de água e de esgotamento sanitário é realizada por uma autarquia municipal, criada em 21 de agosto de 2001, denominada Serviço Municipal Autônomo de Água e Esgoto (SeMAE).. Nas últimas décadas verificou-se, em todo território nacional, a tendência por uma maior participação da iniciativa privada na indústria de saneamento, o que contraria a predominância, em boa parte do mundo, da organização por gestão pública e local. Referenciando-se certas características dos serviços de saneamento, como a essencialidade e monopólio natural, constata-se a premente necessidade de controle social. Mas a falta de recursos, tarifas irrisórias, prática de assistencialismo e ingerências políticas, aliados à má gestão, conduziram a um cenário onde a privatização figurava como salvação. Com a instituição da Política Nacional de Saneamento em 2007 e a maior participação do Governo Federal, por meio da disponibilização de programas e financiamentos para o setor, desenha-se outra realidade. O poder público, agora definido como titular dos serviços de saneamento, passa a trilhar um caminho repleto de obrigações e deveres, na busca da qualidade, eficiência e universalização da prestação. Durante a concepção deste trabalho, por meio de observações das estruturas existentes, institucionais, físicas e operacionais do S.A.E. analisado, utilizando dados coletados e selecionados de forma criteriosa, foram elaborados diagnósticos inicial e de procedimentos, que corroboraram com a evolução desse sistema. Os dados comparativos utilizados originaram-se em grande maioria, do Sistema Nacional de Informação de Saneamento (SNIS). A análise e desenvolvimento deste trabalho permearam-se na esfera econômica. Avaliamos, no período de 2001 a 2008, o sistema de abastecimento de água e esgoto do município de São José do Rio Preto, por meio de parâmetros e valores mensuráveis, demonstrando a sua sustentabilidade.

This master’s thesis deals with the overall sanitary and gas pipeline installation in a supermarket. The theoretical part deals with equipment and requirements for large kitchens with regard to the food preparation in this building. The computing and design part deals with the sewerage, water supply and gas distribution in the supermarket. The property counts over six thousand square meters and is partly two-storeyed. There are also several smaller sales units in addition to the sales areas, facility for staff and warehouses. The diploma thesis is based on current Czech and European regulations.

Diploma thesis describes the design of plumbing systems in student dormitories. The theoretical part discusses the types of waste water, focusing on gray water and its subsequent use. The experimental part is focused on measurement drinking water consumption and drinking water discharge in existing buildings student dormitories and apartment building. The work also contains other variants of possible installation solutions. The project is part of the selected solutions developed a variant form of project documentation for construction.

Urban sewerage systems, which are normally used for the transport of wastewater from its origin to a wastewater treatment plant (WWTP), could be used as a treatment facility because (i) they contain heterotrophic bacteria capable of oxidising organic matter both suspended within the body of the flowing wastewater and attached to the surface of the wetted perimeter, and (ii) they provide retention times which are often comparable to those in a conventional activated sludge aeration tank and which, in some cases, may be equal to the hydraulic retention time in a WWTP. Using sewers as a treatment facility could be an economical method of alleviating the load on an existing WWTP or reducing the size of the proposed WWTP. The current study was undertaken to investigate the feasibility of using urban sewerage systems as suspended growth biological reactors for the treatment of domestic wastewater. The flow in a linear gravity sewer was simulated using a batch reactor fed with raw domestic wastewater. A comparison of simulated aerobic and anaerobic gravity transport indicated that aerobic treatment would be the most favoured method of in-sewer biological treatment. The soluble COD (SCOD) removal efficiencies over a retention period of 8 hours averaged 36 and 6% under aerobic and anaerobic conditions, respectively, at an average temperature of 22°C. The corresponding total COD removal averaged 8 and 11%, respectively. When the effluent samples, taken from the batch reactors after a retention period of 6 hours, were settled in a bench-scale settling column for one hour, the average suspended solids removal under aerobic conditions was 29% greater than those under anaerobic conditions. Under aerobic conditions, the removal of soluble organic matter during simulated gravity transport was found to be strongly influenced by the strength of the incoming wastewater. To investigate the effect of wastewater influent soluble COD (SCOD 0) and influent suspended solids (SS ()) on in-sewer aerobic treatment, 27 individual wastewaters collected from the inlets to three wastewater treatment plants were subjected to batch tests at 20°C. The SCOD over a retention period of 8 hours at 20°C averaged 48, 40 and 61% for wastewaters having low SCODo and low SS 0, high SCOD0 and low SS 0, and high SCOD0 and high SSo, respectively . The corresponding soluble BOD5 removal efficiencies averaged 64, 59, and 81%. A statistical analysis of soluble COD data revealed that, over a retention period of one to three hours, the soluble COD removal is only significantly influenced by SSo. At higher retention periods, the soluble COD removal was found to be significantly affected by both SCOD 0 and SSo. Soluble COD removal was found to follow first-order kinetics with respect to time. The oxygen uptake rate of the individual wastewaters varied widely and did not appear to show any clear relation with the SCOD0 or SSo. An increase in the suspended biomass of the wastewater by the addition of activated sludge, at a concentration as low as 100 mg VSS/1, at the inlet of the simulated aerobic gravity sewer resulted in a significant increase in the removal of soluble organic matter. The soluble COD removal in the seeded wastewater was found to increase almost linearly with the increase in seed concentration in the range of 100-1000 mg/l. The effect of seed concentration on soluble COD removal however, appeared to diminish with the increase in retention time. SCOD removal in the seeded wastewater appeared to follow secondorder kinetics with respect to time. At an initial seed concentration of 100-1000 mg/1, the batch reactor's effluent after a retention period of 6 hours showed satisfactory settling characteristics. The oxygen uptake rate of the seeded wastewater did not show any specific trend over time at seed concentrations of 100 and 250 mg/1, while at higher seed concentrations it was similar to that observed in a typical plug flow activated sludge aeration tank. The results of the case study in which the wastewater collected from the inlet of the Greater Amman Siphon (GAS) was maintained aerobic in a batch reactor, showed that by maintaining aerobic conditions in the GAS, average SCUD and soluble BOD 5 removal efficiencies of 60 and 78%, respectively, could be achieved over 8 hours at an average temperature of 25°C. The average oxygen demand of the wastewater was estimated to be 30 mg/l.h. The result of the current study suggest a strong possibility of using urban sewerage systems as an aerobic biological reactor for the removal of soluble organic matter during transit.

Inflow and infiltration (I/I) water in the sewer network originates from groundwater, precipitation, seawater as well as over-leakage from drinking water pipes. It is the proportion of water in the sewer system that is not wastewater and causes problems both at the treatment plant as well as in the sewer network. Through overflows, floods and bypassing at the treatment plant I/I causes discharges of wastewater to recipients and nature and thus have negative environmental effects. I/I also stand for an overload in the system which, in addition to environmental consequences, also has social, economic and technical consequences. Despite efforts to reduce and mitigate the effects of I/I water for a long time, the problem remains and a large proportion of all the wastewater in the network and the treatment plan still is I/I.  Historically, and for many cases at present, there is little to no methodology for how the work with I/I water takes place and is prioritized in the municipalities and responsible water and sewerage organizations. Measures have instead been implemented with a reaction based approach, in other words when something has broken down or there is a failure in the system. A new discussion about I/I water has arisen in recent years due to new requirements from supervisory authorities. As there is not much follow-up or methodology around the work with I/I water, the process of developing a strategy to meet these new requirements for municipalities has shown to be difficult. In cases where analysis of measures against I/I water has been carried out, cost and effects in the treatment plant (i.e. the proportion of I/I water) have most often been used and dimensions other than economic have been left out of the analysis. As I/I water affects social and environmental factors to a great extent, this should be taken into greater account.  In this work, a multi-criterion analysis has been performed in a case study where similar measures to reduce I/I water and its effects in two different areas have been analysed. The included measures were separation, lining, pipe bursting and installation of a stormwater cassette. The results of the case study show that measure A2 has the greatest positive effect. However, there are major uncertainties in the case study conducted and the results are not considered to be robust enough to be used. However, what has been important to include from the work is that by defining and using criteria from all sustainability dimensions, a comprehensive action choice analysis is created and that it is a structured approach to apply. Here, the importance of opening up for discussion within the municipality/organization is emphasized to achieve a coherent view of the prioritization of I/I water and to achieve efficient management. Problems and amounts of I/I water are complex issues and vary from place to place, and are strongly linked to local geohydrological and climate conditions and design of local sewage systems. Therefore, it is important to coordinate the planning of I/I water to use a workflow that is general and can be used, regardless of conditions, in a simple way where adjustments in accordance with local conditions are possible. This work has shown that multi-criteria analysis is a clear and adaptable tool for meeting the difficulties that exist.<br>Tillskottsvatten härstammar från grundvatten, nederbörd samt havsvatten genom felaktiga anslutningar eller läckage i ledningsnätet samt från överläckage från dricksvattenledningar. Det är andelen av vatten i avloppsnätet som inte är spillvatten och orsakar, genom bräddning, översvämningar och förbiledning i reningsverket, utsläpp av avloppsvatten till recipienter och natur samt står för en överbelastning i systemet. Trots att man arbetat med att minska och lindra effekterna av tillskottsvatten under lång tid så kvarstår problemet och en stor andel av allt samlat vatten i ledningsnätet och som kommer till reningsverket är just tillskottsvatten.  Historiskt, samt för många fall i nuläget, så existerar det lite till ingen metodik kring hur arbetet med tillskottsvatten sker i kommunerna och ansvariga VA-organisationer utan åtgärder har implementerats på måfå eller när något har gått sönder. En ny diskussion kring tillskottsvatten har uppstått de senaste åren på grund av uppkomna nya kravställningar från tillsynsmyndigheter. I och med att det inte finns mycket uppföljning eller metodik kring arbetet med tillskottsvatten så har processen med att ta fram en strategi för att möta dessa nya krav för kommuner ofta varit svår. I de fall som analys av åtgärder mot tillskottsvatten har utförts så har kostnad och effekter i reningsverket (det vill säga andel mängd tillskottsvatten) oftast används och andra dimensioner än ekonomiska har lämnats utanför analysen. Då tillskottsvatten påverkar sociala samt miljömässiga faktorer i hög grad bör detta tas större hänsyn till.  I det här arbetet så har en multikriterieanalys utförts i en fallstudie där liknande åtgärder för att minska tillskottsvatten och dess effekter i olika områden har analyserats. De ingående åtgärderna var separering, infodring, rörspräckning samt anläggning av en dagvattenkassett. Resultatet av fallstudien visar att åtgärdsalternativ 2 har störst positiv effekt. Det finns dock stora osäkerheter i den fallstudie som utförts och resultatet anses inte vara tillräckligt robust för att användas. Det som dock har varit viktigt att ta med från arbetet är att genom att definiera och använda kriterier från alla hållbarhetsdimensioner skapas en heltäckande åtgärdsvalsanalys och att det är ett strukturerat arbetssätt att applicera. Här understryks vikten av att öppna upp för diskussion inom kommunen/organisationen för att nå en sammanhållen syn på prioriteringen av tillskottsvatten samt för att nå en effektiv hantering. Problem och mängder tillskottsvatten i olika ställen är komplext och starkt kopplat till lokala klimat och geohydrologiska förhållanden samt lokala avloppssystem. Därför är det viktigt för att samordna planeringen av tillskottsvatten att använda en arbetsgång som är generell och kan användas, oavsett förutsättningar, på ett enkelt sätt där justeringar i enlighet med lokala förutsättningar är möjligt. Det här arbetet har visat att multikriterieanalys är ett tydligt och anpassningsbart verktyg för att möta de svårigheter som finns.

The untreated overflow of combined sewer system contains a variety of pollutants that can contaminate the receiving water body. Total suspended solids (TSS) transported in the sewer networks can adsorb these pollutants and become the main contaminant source. Existing models contain a numerous formulas that make the calculation process complex and time consuming. A simplified model was presented in this thesis to simulate the process of TSS transport in combined sewer pipes. The combined sewer system evaluated was a combination of an existing sewer system in Le Marais and an example system provided with the Storm Water Management Model (SWMM). SWMM was used in this research to simulate the rainfall event, pollutant build-up and wash-off process, and to provide hydraulic calculations for the combined sewer system. A spreadsheet model was created to calculate the TSS concentration profile and flow velocity profile. The total TSS transport rate was computed using a numerical estimation of the integral of the concentration in the cross-section area multiplied by the velocity. The flow depth, velocity, and Froude number of each pipe was calculated to show that the combined sewer system was under proper working conditions. The first flush phenomenon was observed by plotting the TSS concentration pollutograph of the combined sewer system. From the TSS transport pollutograph, the maximum transport rate was found (0.2609 kg/s at 6:45). The study of TSS profile showed that the concentration distribution was based on the solid density. The TSS particle also affected the transport rate. A sensitivity analysis of particle size was conducted in this thesis. A second order polynomial was used to describe the relationship between median particle size d50¬ ¬and TSS transport rate.

Streams and springs have in some cases been connected into the combined sewer system. These “lost watercourses” contribute another source of clean baseflow to sewer networks, in addition to the widely acknowledged and researched infiltration-inflow. Stream and spring capture, as a type of point source inflow to combined sewer networks, has received little specific acknowledgement by the water industry in the UK. The considerable efforts to tackle sewer infiltration-inflow may be confounded by this type of inflow. A literature review demonstrates that stream and spring capture occurs in many cities around the world, and discusses the causes, the costs and consequences, and the potential solutions, with particular reference to Zurich. Evidence that can be used to identify stream and spring capture is reviewed and demonstrated with a case study of Sheffield, UK. It is found that no single source of information can always be relied on to indicate capture. Over half the total original stream length in the search area is now lost, and may be captured into the combined sewers. A novel water typing method is developed that can be used to indicate stream and spring capture sites from the major and minor ion water chemistry. Results of a detailed sampling program of five capture sites in Sheffield are presented, demonstrating that water types can reflect sites of known capture in some circumstances. Finally a Bayesian Belief Network model is developed to predict where both stream and spring capture and infiltration-inflow are likely to occur in a sewer network, providing a useful scoping tool for water companies. Expert beliefs are used to predict the likelihood of stream and spring capture and infiltration-inflow from various sewer characteristics, and proximity to recorded “lost” streams and springs. The model is robustly evaluated using several validation data sources, suggesting that it performs well.

Thesis (M.S.)--University of North Carolina at Chapel Hill, 2007.<br>Title from electronic title page (viewed Apr. 25, 2008). "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Environmental Science and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.

För att klara av den befolkningsökning som sker i städerna projekteras nybyggnadsområden. Innan byggnation av bostäder kan ske måste ett beslut tas om val av spillvattensystem. I nuläget saknas enkla hjälpmedel för att jämföra och göra val baserat på systemens totala kostnader under dess livslängd. Målet med detta arbete var att ta fram en beräkningsmall som kan göra en livscykelkostnadsanalys samt vara ett komplement vid projektering och val av spillvattensystem. Topografin och områdesspecifika kostnader bryts ner och förs in i beräkningsmallen för den sträcka där spillvattenledningen ska anläggas. Mallen kontrollerar därefter om områdets förutsättningar uppfyller de krav som finns för spillvattenledningar eller ej. Resultatet som erhålls av beräkningsmallen påvisar initiala-, årliga och ackumulerade kostnader för de båda systemen. Skillnader och eventuella brytpunkter mellan ackumulerad kostnad för de båda systemen redovisas och kan användas som underlag vid val av spillvattensystem. Arbetet visade att det finns ett stort b<br>In order to cope with the population increase that occurs in the cities, new construction areas are being planned. Before the construction of housing can take place, a decision must be made regarding the choice of sewerage system. At present there are no simple tools to compare and make choices based on the systems total lifetime cost. The aim of this thesis has been to develop a calculation template that can perform a life cycle cost analysis and to be a complement to the project planning and choice of sewerage systems. The topography and area-specific costs are broken down and entered into the calculation template for the distance where the wastewater pipeline is to be constructed. The template then checks whether the area's conditions meet the requirements for wastewater pipelines or not. The result obtained from the calculation template shows initial, annual, and accumulated costs for the two systems. Differences and possible breakpoints between the accumulated cost of the two systems are reported and can be used as a basis for decision. The work showed that there is a great need for supporting tools to facilitate the planning and decision making of water systems.

Combined sewer networks control, like many other real world problems, is usually identified with competing and conflicting objectives. Decision makers have a great need of selecting the best possible control strategy in minimizing the combined sewer overflows (CSOs) when controlling the sewer networks. However, this control strategy should be cost effective to produce a feasible control approach in real world. Cost effectiveness has become significantly important in present economic recession. Over the past decades, people have witnessed the control strategies based on minimization of CSOs. However, it is now, not only to minimize CSOs, but also to minimize the impact to the natural water from these CSOs. Therefore, this research explores the development of a holistic framework that is used for the multi-objective optimization of urban wastewater systems, considering flows and water quality in combined sewers and the cost of wastewater treatment. Pollution levels of several water quality parameters in dry weather flows and stormwater runoff are considered. Pollutographs for several water quality parameters are generated for the stormwater runoff. Temporal and spatial variations of the stormwater runoff are incorporated using these pollutographs for different land-uses. Furthermore, pollutographs are developed for different storm conditions, including single, two consecutive and migrating storms. Evolutionary algorithms are extensively used in solving the developed multiobjective optimization approach. Formulations for two different optimization approaches, one for the snapshot optimization and the other one for the dynamic optimization are developed. Simulation results from a full hydraulic model, including water quality routing are used in the optimization. The performance of the multi-objective optimization models are tested on a simple interceptor sewer system for several storm conditions. The proposed optimization approach for snapshot optimization gives the optimal CSO control settings where a single set of static control settings is used throughout the considered time period. However, the proposed optimization approach for dynamic optimization is capable of producing control strategies over the full duration of storm period. Furthermore, results for a number of alternative formulations in constraint handling for the developed multi-objective optimization approach are compared. They produce interesting findings. Overall, the constraint handling formulations developed outside the genetic (NSGA II) algorithm provides better control in combined sewer networks. In addition, the results of the multi-objective optimization demonstrate the benefits of the usage of optimization approach and its potential to establish the key properties of a range of control strategies through an analysis of the various tradeoffs involved. Solutions from the dynamic optimization approach highlight the usage of the real-time control in combined sewer systems. Given that the technology is there to measure water quality and flow rates, collect data and send feedbacks to the sewer system through central processing unit and the usage of high performance computers, the developed optimization model is capable of handing the present society's concerns in combined sewer systems. The model is capable of controlling the existing sewer networks according to the receiving water regulations and the fund availability of the wastewater treatment plants. However, further research is required to apply the developed multi-objective optimization approach in real-time control of urban sewer systems.

There is a need to evaluate different technologies such as FeCl2, H2O2 and O2 addition as odor and corrosion control alternatives to determine required dosages and detention times. The goal of this research is to study the kinetics of H2S removal using the techniques commonly employed in sanitary sewer systems to determine the effectiveness of each process. To achieve this objective a laboratory simulation of these chemicals additions was carried out using completely mixed BOD bottles as batchreactors. The BOD reactor was filled with a 7 mg/L H2S solution. FeCl2, 50%-H2O2, O2 and a combination of FeCl2 and H2O2were added to the reactors containing H2S solution and the concentration of H2S remaining was measured after certain reaction times. A rate expression based on experimental data was generated using the integration method. The rate constants (k) and the order of the reaction (n) were calculated from the concentrationtime data. For a range of temperature of 12 oC and 14 oC and pH 7, the oxidation of H2S with FeCl2 adheres to second-order reaction kinetics. The removal of H2S using H2O2 is well described by the third-order kinetic for a temperature range between 10 oC and 17 oC and pH 7. H2S oxidation by the combination of FeCl2 and H2O2 can be described by third-order reaction kinetic in a temperature range of 15-20oC and pH 7. The removal of H2S injecting O2 to force mains suggests a second-order reaction kinetic at 22.5 oC and pH 7. Summing up, FeCl2 treatment requires the addition of large quantities to be effective. Also, O2 injection was ineffective across the range of pure oxygen investigated. Conversely, 50% H2O2 is the most effective chemical control strategy for the mitigation of H2S investigated. Maximum percent H2S removals using combination of FeCl2 and H2O2 were in the 90s. In this case most of the H2S is oxidized by H2O2, which means that FeCl2 addition does not have a significant effect on the removal of H2O2. In every case, the initial concentration of the reactant used has a significant effect on the values of both k and t1/2.

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Engenharia Sanitária<br>This thesis was carried as a collaboration of Delft University of Technology (TU Delft) and the companies Waternet and KWR. The main project aims to study the possibility of thermal energy recovery from wastewater, reducing the carbon dioxide (CO2) emissions linked to the energy sector. The present work is based on a previous computational model that was developed to simulate heat recovery from wastewater for constant flow rate and temperature of water. The first goal is to simulate a wastewater discharge. In order to achieve this, a Gaussian function was added to the boundary conditions for water flow rate and water temperature. As a second goal, this work aims to assess the significance of the terms present in the water heat balance and air heat balance equations. Binary coefficients were added in each term of both equations and then all the combinations were computed. The unsteady situation successfully simulated a main discharge and numerical predictions for water temperature and flow rate are presented. The deviations associated with the modified cases for the two equations suggest that the heat flux pipe to water (!!") and heat flux pipe to air (!!") terms are crucial for water and air heat balance predictions,respectively. In order to smooth extra oscillations, the time step (dt) was reduced and a smaller relative size of oscillations was obtained. This work concludes with a section of future developments in order to improve the results obtained. Despite of the fact that the current state of these routines does not allow us to accurately assess heat exchanges in pipes, promising results were obtained, proving that numerical modelling of heat recovery will contribute greatly to the development of the main project.

This thesis assesses the potential of Venezuela’s technical water committees (mesas técnicas de agua, MTAs) to address governance and logistical challenges for improving sanitation in the barrios (low income settlements) of Caracas. The MTAs are a radical experiment in urban planning whereby beneficiary communities map their own water and sanitation needs and help to plan infrastructure development, which is financed by the state. In addition to improving services, the MTAs aim to promote “popular” or “citizen power” as part of a broader political transformation, the Bolivarian Process (1999-present). Based on Hickey and Mohan’s (2005) four criteria for “transformative participation,” the paper argues that the MTAs have opened spaces for citizen empowerment and improved services in the barrios; however, participation at the local scale cannot resolve many of the challenges for improving sanitation such as institutional overlap and the financing gap, especially given that sanitation is the least profitable form of service provision in terms of economic and political payoffs.

Blockages have been reported to account for a significant proportion of reported failures in sewer networks. The malfunctioning of the sewer network from blockages and the subsequent disruption to other public services and flooding may constitute a risk to the environment and human health. Due to the complex nature of underground sewer networks, a reactive approach to blockage maintenance is typically employed. However, although proactive maintenance strategies have been developed, both approaches could be expensive and highlight the need to address the problem with analytics-based methods. Although blockage triggering mechanisms may be known, sewer blockages often appear at random. Thus, it is necessary to improve the understanding of the influential mechanisms involved in forming blockages in sewer networks to support its maintenance and guarantee adequate performance levels. The overall aim of this thesis was to contribute with new knowledge, approaches and methods that can support improved proactive maintenance planning of blockages in sewer networks. Various methods to achieve the aim have been investigated in relation to asset management planning levels. At the strategic level, blockages and associated performance indicators were employed in conjunction with Poisson and partial least squares regression to assess the performance of sewer networks, including gaining additional insights. At the tactical and operational levels, a procedure was developed. The procedure combines network k-function, geographically weighted regression and random forest ensembles. The network k-function analysis explains the significance of the spatial variation of blockages. The Geographically weighted Poisson regression (GWPR) investigates the degree of influence of explanatory factors on increased blockage propensity in differentiated segments of the sewer networks. Thirdly, the random forest ensembles was used to predict pipes with blockage recurrence likelihood. A proposed conceptual framework was applied at all asset management levels to assess the state of data-driven integrated asset management (IAM), based on data quality assessments, interoperability evaluations between IAM tools, and data collection and informational benefits analysis.  Results from demonstrating the methods with data from the Swedish waters statistical database and three Swedish municipal sewer networks, namely A, B and C, are presented. Blockage related performance indicators showed that the average blockage rate in medium sized networks was 2-3 times the rate in other sewer networks in Sweden. Furthermore, sewer maintenance strategies were suspected to be ineffective, and increased proactive strategies may improve maintenance efficiency. The procedure in networks A, B and C indicated that the clustering of recurrent blockages maybe linked to an increased need for flushing-related maintenance in sewer pipe networks. The degree of influence between investigated factors and increased blockage propensity indicated that these relationships were not global (not the same in all locations) within and between the sewer networks for networks A, B and C. These non-stationary relationships were observed to occur in various forms, i.e. adequate self-cleaning velocity showed positive and negative correlations in different locations. The networks with relatively more substantial spatial clusters of blockages, higher data quality and availability were observed to have a higher mean prediction accuracy. The applied conceptual framework showed that intuitive asset management characterised the current state of blockage management in the municipal sewer network C with medium to good data quality and low interoperability.

Diploma thesis contains a design the plumbing and gas installations in the industrial building. The theoretical part deals with the use of rainwater in the building as the process water and the experimental determination of the flow rate and water needs for the manufacturing and storage hall with built-office. The calculation part deals with the design of variants of plumbing and gas installations in the building manufacturing and storage hall with built-office. The practical part contains a design and project documentation of selected variants plumbing and gas installations in the manufacturing and storage hall with built-office, and the use of rainwater in this type of building.

Thesis (MScEng)--Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: This research project focuses on sanitary sewer systems. When performing an analysis of a sewer drainage system with known constraints, an appropriate model needs to be chosen depending on the objectives of the analysis. Uncertainties are also present in the analysis of sewer drainage systems. The uncertainties and the errors in hydraulic models need to be understood and considered. The required level of accuracy and the type of hydraulic problem that needs to be solved may alter the complexity of the hydraulic model used to solve a drainage system. The wide variety of available simulation models further complicates model selection. With various models available, selecting the most appropriate model for a particular drainage system simulation is important. The various models for sewer drainage system analysis can be categorised in different ways. For example, it is possible to categorise models according to their purpose, which could be evaluation, design or planning. Evaluation models are mainly used to test whether existing systems or planned systems are adequate and require the highest hydraulic detail. Design models are used to determine the size of conduits within a drainage system and require moderate levels of hydraulic detail. Planning models are primarily used for strategic planning and decision making for urban or regional drainage systems and require the least amount of hydraulic detail. An understanding of the available models is required in order to choose the most suitable simulation model for the desired purpose. Some models are derived from the Saint-Venant equations of flow. The most detailed models are typically referred to as fully dynamic wave models and utilise all the components of the Saint-Venant flow equations. By removing terms from the Saint-Venant equations a kinematic wave model can be created. Some less complex models ignore basic principles of hydraulics in order to make assumptions that simplify the process of simulating flows. In this thesis three different models were compared: a detailed model using fully dynamic flow equations, a simplified model using kinematic wave equations and a basic model using contributor hydrograph routing equations. For the drainage system analysis SWMM-EXTRAN was used as the fully dynamic wave model, SWMM-TRANSPORT was used as the kinematic wave model and SEWSAN was used as the contributor hydrograph model. Two drainage systems situated in South Africa were used as case studies and are referred to as Drainage System A and Drainage System B in this thesis. The actual flow rate was recorded at two points with flow loggers, one in each of the two systems. The flow rate was continually recorded at 1 hour intervals for the period 1 July 2010 to 9 July 2010 in Drainage System A as well as in Drainage System B. The same input parameters were used for each model allowing the modelled flow rates to be compared to the measured flow rates. The models provided peak flow results that were within 2% of the measured peak flow rates and the modelled mean flows were within 8.5% of the measured mean flows in most situations. However, when rapidly varied flows occurred the kinematic wave and contributor hydrograph models returned conservative results as they were unable to account for hydraulic effects such as acceleration. The effect of acceleration became most pronounced up and downstream of drop structures and sections where the slope changed considerably. The kinematic wave and contributor hydrograph models were therefore unable to accurately simulate surcharge conditions. The results suggest that the fully dynamic wave model can be used in all scenarios. The kinematic wave model can be used for a design analysis if no hydraulic structures occur in the system. The contributor hydrograph model should not be used for an evaluation analysis, but can be used for a design analysis if a relatively high level of confidence in the parameter set exists and no areas of rapidly varying flow or hydraulic structures exist within the system.<br>AFRIKAANSE OPSOMMING: Hierdie navorsing projek is gefokus op riool dreineringsisteme. Wanneer ʼn analise van ʼn riool dreineringsisteem met bekende beperkinge onderneem word, moet ʼn geskikte model gekies word afhangende van die doelwitte van die analise. Onbekendes is ook teenwoordig in die analise van riool dreineringsisteme. Dit word belangrik dat die onsekerhede en die foute in hidroliese modelle moet verstaan en oorweeg word. Die verwagte vlak van akkuraatheid en die tipe hidroliese probleem wat opgelos moet word mag die ingewikkeldheid van die hidroliese probleem, wat gebruik word om ʼn rioolsisteem op te los, verander. Die wye verskeidenheid van beskikbare simulasie modelle bemoeilik verder die keuse van ʼn model. Met etlike modelle beskikbaar vir seleksie, is die mees geskikte model vir ʼn spesifieke dreineringsisteem simulasie belangrik. Die verskeie modelle vir riool dreineringsisteem analise kan op verskillende wyses gekategoriseer word. Byvoorbeeld, dit is moontlik om modelle te kategoriseer volgens hulle doel, wat evaluasie, ontwerp en beplanning kan wees. Evaluasiemodelle word hoofsaaklik gebruik om te toets of huidige of beplande sisteme voldoende is en of hulle die hoogs moontlike hidroliese besonderhede benodig. Ontwerpmodelle word gebruik om die grootte van ʼn leipyp binne ʼn rioolsisteem te bepaal en benodig matige vlakke van hidroliese besonderhede. Beplanningsmodelle word hoofsaaklik gebruik vir strategiese beplanning en besluitneming vir stedelike en landelike rioolsisteme en benodig die laagste vlak van hidroliese data. ʼn Begrip van die beskikbare modelle is nodig om ʼn keuse te maak rakende die mees geskikte simulasie model vir die verlangde doelwit. Sommige modelle is afkomstig van die Saint-Venant vergelykings van vloei. Die mees gedetailleerde modelle word tipies na verwys as die volledige dinamiese golf modelle en benut alle komponente van die Saint-Venant vloei vergelykings. Deur die verwydering van terme van die Saint-Venant vergelykings kan ʼn kinematiese golf model daargestel word. Sommige minder gekompliseerde modelle ignoreer die basiese beginsels van hidrologie om aannames te maak wat die proses van golf simulering vereenvoudig. In hierdie tesis is drie verskillende modelle vergelyk; ʼn gedetailleerde model wat volledige dinamiese vloeivergelykings gebruik; ʼn vereenvoudigde model wat kinematiese golfvergelykings gebruik en ʼn basiese model wat bydraende hidroliese versending vergelykings. Vir die dreineringsisteem analise was SWMM-EXTRAN gebruik as die volledige dinamiese golfmodel, SWMM-TRANSPORT was gebruik as die kinetiese golfmodel en SEWSAN was gebruik as die bydraende hidroliese model. Twee dreineringsisteme in Suid-Afrika was gebruik as gevallestudies en word na verwys as Dreineringsisteem A en Dreineringsisteem B. Die werklike vloeikoers was aangeteken by twee punte met vloeimeters, een in elk van die sisteme. Die vloeikoers was deurlopend opgeteken met 1 uur tussenposes vir die periode 1 Julie 2010 tot 9 Julie 2010 in Dreinering Sisteem A sowel as Dreinering Sisteem B. Dieselfde inset parameters was gebruik vir elke model wat dit moontlik gemaak het dat die gemoduleerde vloeikoerse met die gemete vloeikoerse vergelyk kon word. Die modelle het spits vloeiresultate voorsien wat binne 2% van die gemete spits vloeikoerse was en, in die meeste situasies, dat die gemoduleerde gemiddelde vloei binne 8.5% van die gemete gemiddelde vloei was. Wanneer vinnig varierende vloei voorgekom het, die kinetiese golf and bydraende hidrograaf modelle konserwatiewe resultate gelewer het, aangesien hulle nie in staat was om hidroliese effekte soos versnelling te verklaar nie. Die effek van versnelling was op sy duidelikste stroomopwaarts en stroomafwaarts onder valstrukture en by gedeeltes waar die helling aansienlik verander het. Die kinetiese golf en bydraer hidrograaf modelle was gevolglik nie in staat om oorladingsomstandighede akkuraat te simuleer nie. Die resultate wys dat die volledige dinamiese vloeimiddel gebruik kan word in alle omstandighede. Die kinematiese vloeimiddel kan gebruik word vir ʼn ontwerp analise indien geen hidroliese struktuur in die sisteem voorkom nie. Die bydraer hidrograaf model behoort nie gebruik te word vir ʼn evaluerings analise nie, maar kan gebruik word vir ʼn ontwerp analise indien ʼn relatiewe hoë vlak van vertroue in die parameter stel bestaan en geen area van vinnig veranderende vloei of hidroliese strukture binne die sisteem bestaan nie.

La gestion incorrecte des eaux usées peut entraîner des dommages importants sur les stations de traitement et sur le récepteur final (écosystème aquatique). Dans le passé, la gestion des eaux usées n'a pas retenu beaucoup d'attention de la part des différentes parties prenantes. Toutefois, récemment, le changement de modèle de gestion des eaux usées et des eaux pluviales, a évolué du simple contrôle sanitaire et des inondations, à une protection globale de l'environnement. Un aspect très important, dans la politique de gestion des systèmes d'assainissement, est de détecter et d'éliminer une intrusion illicite, qui peut être intentionnelle. Ce travail thèse de doctorat est constitué de deux parties principales. Dans la première partie les problèmes relatifs à l'identification d'une intrusion illicite dans un système d'assainissement ont été abordés, proposant une méthodologie d'identification de la source (IS). Dans la deuxième partie, différentes méthodologies innovantes ont été proposées pour trouver l'emplacement optimal d'un nombre limité de capteurs dans le système d'assainissement. Dans cette thèse, le ISest résolu grâce à un modèle de simulation-optimisation, combinant l'outil de simulation Storm Water Management Model (SWMM) avec un code d'optimisation basé sur un algorithme génétique (Galib). Ceci nécessite des mesures en ligne de certains capteurs placés sur le réseau. Le SWMM ne possède pas l'outil de programmation. Afin d'intégrer le simulateur SWMM à la méthodologie de IS automatisé proposée, un outil ad-hoc a été développé. Une procédure de présélection, basée sur le concept de la matrice de la pollution et compte tenu de la topologie des égouts, a été mis en œuvre pour réduire l'effort de calcul. La méthodologie IS a été testée sur deux réseaux différents. L'un est un réseau connu dans la littérature, extrait du manuel de SWMM, tandis que l'autre réseau est un sous-bassin versant du réseau d'assainissement de Massa Lubrense, village situé près de Naples, en Italie. Les résultats montrent que les procédures de présélection réduisent considérablement l'effort de calcul, avec un rôle crucial pour les grands systèmes. En enquêtant sur la performance de la méthodologie IS, sa sensibilité par rapport aux paramètres de l'algorithme génétique a été vérifiée. En outre, l'influence de l'incertitude des flux entrés et des erreurs de mesure sur les résultats ont été approfondi. Un autre problème fondamental, associé à la surveillance de la qualité de l'eau des égouts, est le placement optimal d'un nombre limité de capteurs pour la détection précoce d'une source illicite. Dans la thèse l'emplacement du capteur est exprimé avec un problème d'optimisation mono ou multi-objectif. Le SWMM est utilisé pour extraire les données de qualité de l'eau. Différentes formulations ont été proposées et testées. Tout d'abord, la Théorie de l'Information (TI) basée sur la méthodologie d'optimisation multi-objectif est présentée. La TI considère deux objectifs : l'entropie conjointe, le contenu de l'information dans un ensemble de capteurs, qui est maintenu aussi haut que possible ; la corrélation totale, une mesure de la redondance, qui est maintenue aussi faible que possible. Dans la seconde approche multi-objectifs le temps de détection doit être minimisé et la fiabilité qui doit être maximisée. Les deux cas, les problèmes multi-objectifs sont résolues en utilisant l'algorithme Non-Dominating Sorting Genetic Algorithm-II (NSGA-II). Comme troisième alternative, un outil d'optimisation mono-objectif (Greedy) a été testé. Les objectifs précédemment considérées sont utilisés avec différentes combinaisons. Le réseau d'assainissement de Massa Lubrense a été utilisé pour tester les performances des différentes procédures proposées. Une comparaison normalisée entre toutes les approches montre que l'approche basée sur Greedy pourrait être une alternative pratique pour l'optimisation des emplacements de capteurs dans les systèmes d'assainissement<br>Improper wastewater management could result in significant damage to the treatment plants and the final recipient aquatic ecosystem. In the past, wastewater management did not get much attention from different stakeholders. However, recently a paradigm shift of wastewater and storm water management is evolving from a simple sanitary and flood control, respectively, to a whole environmental protection function. A very important aspect of the sewer systems management policy is to detect and eliminate an illicit intrusion. This PhD research is consisting of two main pillars. In the first pillar, the issues regarding the identification of an illicit intrusion in a sewer system have been addressed, proposing a source identification (SI) methodology. In the second pillar, different innovative methodologies have been proposed to find the optimal placement of a limited number of sensors in the sewer system. In the thesis, the SI is solved through a simulation-optimization model, combining the hydraulic and quality simulation tool Storm Water Management Model (SWMM) with a genetic algorithm code (GALib) as an optimizer. It requires online measurements from some sensors placed on the network. The SWMM does not have the programmer's toolkit. To integrate the SWMM simulator with the proposed automated SI methodology, an ad-hoc toolkit has been developed. A pre-screening procedure, based on the pollution matrix concept and considering the topology of sewers, has been implemented to reduce the computational effort. The SI methodology has been tested on two different networks. One is a literature network taken from the SWMM example manual while the other is one sub-catchment of the real sewer network of Massa Lubrense, a town located near Naples, Italy. The results show that the pre-screening procedure reduces the computational effort significantly, and it has a crucial role in large systems. In investigating the performances of the SI methodology, its sensitivity respect to the genetic algorithm parameters has been verified. Moreover, the influence of the uncertainty of the inflows values and the measurement errors on the results have been investigated. Another core problem associated with the water quality monitoring of sewers is represented by the optimal placement of a limited number of sensors for the early detection of an illicit source. In the thesis, the sensor location is expressed as a single or multi-objective optimization problem and the SWMM is used to extract the water quality data. Different formulations have been proposed and tested. First, an Information Theory (IT) based multi-objective optimization methodology is presented. The IT approach considers two objectives: the Joint entropy, the information content of a set of sensors, which is kept as high as possible; the Total correlation, a measure of redundancy, which is kept as low as possible. In the second multi-objective approach Detection time, to be minimized, and Reliability, to be maximized, are considered. In both cases, the multi-objective problems are solved using the Non-Dominating Sorting Genetic Algorithm-II (NSGA-II). As a third alternative, a single objective Greedy based optimization tool has been tested. The previously considered objectives are also used with different combinations. The Massa Lubrense sewer network is used to test the performances of various proposed procedures. A normalized comparison among all approaches shows that the Greedy based approach could be a handy alternative for optimizing the sensor locations in sewer systems

The presence of sediment deposits within sewerage systems may lead to operational (premature surcharging and surface flooding) and potential environmental problems (sediments act as a store of pollutants which can be released during erosion events). The consequences of allowing these problems to persist have been recognised internationally. In the U.K., the water industry has promoted fundamental and applied research to develop the necessary operational and analytical tools to manage these problems. Under the Urban Pollution Management Research Programme the major aspects of sediments in sewers have been studied and their effects included in new methodologies and tools. Most studies in the U.K. and elsewhere have concentrated on the movement of non - cohesive sediments, whilst it has been recognised that combined sewer sediment deposits possess cohesive characteristics (although this cohesion primarily arises from agglutination and biological processes in the combined sewer rather than classical concepts of cohesion). New computer based models, e.g Mosqito (Moys 1987) and MOUSETRAP (WRc 1993) , are based on sediment transport capacity theories with the limited availability of sediment within the system recognised through storage layers which become available only when certain threshold levels of shear stress are exceeded. Studies in the U.K. to estimate the release of pollutants stored within sewer sediment beds also require a knowledge of the hydraulic shear stress conditions at which the sediment beds will erode and become entrained into the flow. The reported study examines the apparent cohesive nature of a sediment bed in a large diameter sewer concurrently with flow hydraulics, sediment bed deposit depth and suspended solids flux for a number of dry and wet weather periods. Instrumentation was developed and assessed for hydraulic measurements within the study sewer system and in particular, a novel system was devised to improve flow measurement accuracy in large diameter sewers. Development work was also undertaken on an ultrasonic device to monitor the temporal variation in sediment deposit depth at a point. The constituent materials of the sediment bed were examined and rheological techniques were employed to assess the structural strength of the sediment bed present in the study sewer. The results confirmed the apparent cohesive nature of the sediment bed, with the structural strength of the bed far exceeding the normal hydraulic shear stress ranges encountered in the sewerage system. A relationship between apparent yield strength and liquid content of the sediment bed was obtained from the rheological tests. The bed structural strength was then compared with temporal changes in the flow - induced shear forces. An empirical model was developed to predict the availability for erosion of the cohesive deposits in the combined sewer studied. This model was tested against further temporally varying data sets from the sewer and was found to predict the erosion of the sediment bed under varying levels of applied shear stress together with changes in the sediment transport flux. It was concluded that when Dry Weather Flows induce bed shear stresses in excess of 1-2 N/m erosion of the sediment bed structure can be caused, with storm flows which induce shear stresses in excess of 4-6 N/m eroding the bed to a greater depth. The sediment bed was observed to be rapidly re-established following an erosion event. The investigation and model developed contribute significantly to knowledge about the behaviour of sediments in sewers and provide for the first time a model to simulate erosion of a sediment bed with apparently cohesive properties and consequent increase in sediment and pollutant transport rates.

In the design of urban drainage systems, synthetic design storms are commonly used to predict the peak flow rate in sewer systems and such storms are usually based on local intensity-duration frequency curves or design storm profiles. To estimate the quality of storm flow, the UPM Manual (1994) has highlighted the development of detailed and sophisticated simulation models to estimate the pollutographs, that is, the temporal variation in the concentration of pollutants in urban drainage systems. The data requirements of these models are quite onerous, and as a consequences implified models like SIMPOL have been developed. This model predicts the BOD at 1 hour time intervals and is based on the representation of the sewer system by a series of tanks. This approach may be considered satisfactory for the prediction of accumulative pollution over an annual series of events but for the prediction of acute effects, for example, the first foul flush, the temporal variation in the concentration pollutants in sewer flow is required. There is a need therefore to describe the change in pollution over a much smaller time interval than that proposed in SIMPOL and this is particularly so when consideration is given to the comparison of the design and control options which may be proposed, for example, the real time control of storage tanks to retain the first flush of pollutants. The work outlined in this thesis presents an alternate simple methodology to estimate the pollutographs corresponding to a particular storm event. The work is based on the results of the measured pollutographs recorded on the WRc sewer quality archive (1987) from two catchments at Great Harwood and Clayton-le- Moors in the North West of England. The relationships for the shape of the pollutograph were obtained by the direct comparison of the observed pollutographs. The peak TSS concentrations were obtained by a detailed regression analysis of the observed peak TSS concentrations, the antecedent dry weather period and the hydrological parameters of maximum rainfall intensity, average rainfall intensity and storm duration. These parameters were then related to the shape of the pollutograph and the results of this methodology were shown to satisfactorily reproduce results for the catchments considered. For practical applications, the suggested procedure provides a methodology to calibrate the design pollutographs for any catchment from a limited number of monitored storm events and to utilise these together with time series storms to assist in the performancea ssessmenat nd selectiono f alternative design options. The work has the limitation that it is catchment specific but as more information for different catchments becomes available, it may be possible to establish standard pollutographs for application to a wide range of catchment conditions.

<p>In the planning and design of sewer networks, most of the decisions are spatially dependent because of the right of way considerations and the desire to have flow by gravity. This research addresses the application of combined optimization-geographic information system (GIS) technology in the design process. The program developed for the design uses selected manhole locations to generate the candidate potential sewer networks. The design area is delineated into subwatersheds for determining the locations for lift stations when gravity flow is not possible. Flows from upstream subwatersheds are transported to the downstream subwatersheds via a force main. The path and destination of each force main in the system is determined by applying the Dijkstra's shortest path algorithm to select the least cost path from a set of potential paths. This method seeks to minimize the total dynamic head. A modified length is used to represent the length of each link or force main segment. The modified length is the physical length of the link (representing the friction loss) plus an equivalent length (representing the static head). The least cost path for the force main is the path with the least total modified length. The design approach is applied to two areas in the town of Blacksburg, Virginia. The resulting network and the force main paths are discussed.</p><br>Master of Science