Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [289]-298).

Thesis (M.A.)--Central Connecticut State University, 2000. / Thesis advisor: Clayton A. Penniman. " ... in partial fulfillment of the requirements for the degree of Master of Arts in Biology." Includes bibliographical references (leaves 103-107).

Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains iv, 72 pages. Bibliography: p. 57-60.

No description available.

Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 156-161).

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.

No description available.

L’optimisation du système d’assainissement et la réduction des rejets d’eaux résiduaires urbaines non traitées est devenue un enjeu majeur pour de nombreuses collectivités dans le but d’atteindre les objectifs de qualité des milieux aquatiques fixés par la Directive Cadre européenne sur l’Eau (DCE 2000/60/CE). Pour cela, une parfaite connaissance du système d’assainissement est nécessaire. L’objectif de cette thèse, financée par la CDAPP et l’Agence de l’Eau Adour Garonne, était l’étude de la dynamique du système d’assainissement de la CDAPP et de sa contribution sur les flux de polluants dans le milieu récepteur (le Gave de Pau). La première étape du travail a été consacrée à la caractérisation hydraulique et physicochimique du système d’assainissement par temps sec et par temps de pluie. Une étude hydraulique a été tout d’abord réalisée et a permis de mieux appréhender la dynamique des déversements via les déversoirs d’orage (DO) en fonction de la nature des évènements pluvieux. D’autre part, la caractérisation physico chimique des eaux usées (matières en suspension ou MES, demande chimique en oxygène ou DCO, métaux, hydrocarbures aromatiques polycycliques) a mis en évidence que pour l’ensemble de ces paramètres, une nette augmentation des flux par temps de pluie était observée en particulier en début d’événement (augmentation d’un facteur de 2 à 10). Ce phénomène s’explique par l’apport de polluant par les eaux de ruissellement et l’érosion des dépôts accumulés par temps sec dans les réseaux. Seul l’azote total se comporte différemment puisqu’il est majoritairement présent sous forme dissoute. Afin de mieux appréhender la dynamique des paramètres polluants réglementaires (MES, DCO et azote), un suivi haute fréquence (au pas de temps de cinq minutes) a été mis en place durant un an à l’aide de sondes de turbidité et de conductivité. Ce suivi en continu constitue la troisième partie de ce travail. Des corrélations (r² ≈ 0,9) ont été établies entre d’une part, les paramètres polluants DCO et MES, et la turbidité et d’autre part, entre la conductivité et l’azote total. Ces enregistrements ont permis une meilleure compréhension du fonctionnement du système d’assainissement : mise en évidence du phénomène de first flush, estimation des flux polluants déversés via les DO, étude des phénomènes de stockage dans les réseaux. La dernière partie de cette thèse vise à l’étude de la contribution des rejets d’assainissement dans le milieu récepteur. Elle a permis de démontrer la contribution modérée du rejet de sortie de STEP (entre 1 et 15 %) par temps sec. Par temps de pluie, la contribution du système d’assainissement via les DO est extrêmement variable suivant les conditions hydro-climatiques (de < 1 % à plus de 50 %). Ce travail a permis d’une part d’apporter des résultats utilisables par le gestionnaire de l’assainissement pour optimiser la gestion des eaux usées de la CDAPP. D’autre part, ce travail apporte des résultats plus fondamentaux relatifs à une meilleure connaissance de la dynamique hydrologique et physicochimique des eaux résiduaires urbaines et des polluants associés tels que la mise en évidence, à l’aide d’outils statistiques, des paramètres influençant les déversements et les concentrations en polluants par temps de pluie. / Optimization of sewer system and reduction of untreated wastewater discharges has become a key issue for many communities in order to achieve the good quality of aquatic environments set by the European Framework Directive (WFD 2000/60/EC). For this, a perfect knowledge of sanitation is required. The objective of this thesis, funded by CDAPP and Adour Garonne Water Agency, was the study of the dynamics of the CDAPP sanitation and its contribution to the pollutants fluxes in the receiving environment (the river Gave de Pau). The first step of the work was devoted to the hydraulic and physicochemical wastewater characterization during dry and wet weather. A hydraulic study was first carried and helped to better understand the dynamics of discharges through the combined sewer overflow (CSO) according to the rainfall events characteristics. On the other hand, the physico-chemical characterization of wastewater (suspended solids or TSS, chemical oxygen demand or COD, metals, polycyclic aromatic hydrocarbons) showed that for all these parameters, a clear increase of pollutant fluxes was observed at the beginning of the rainfall event (increase by a factor of 2 to 10). This phenomenon is explained by the runoff contribution and erosion of sediments accumulated in the networks during dry weather periods. Only total nitrogen behaves differently because it’s mostly dissolved. To better understand the dynamics of pollutants parameters (TSS, COD and nitrogen), high frequency monitoring (every five minutes) has been established for one year with turbidity and conductivity sensors. This continuous monitoring is the third part of this work. Correlation functions (r² ≈ 0.9) were found between, the pollutant parameters COD and TSS, and turbidity, and secondly, between conductivity and total nitrogen. These records allowed a better understanding of sanitation system: highlighting the first flush phenomenon, estimation of pollutant loads discharged by CSO, study of storage networks phenomenon. The last part of this thesis aims to study the contribution of wastewater discharges to the receiving environment. It demonstrated the moderate contribution of rejection output STEP (between 1% and 15%) in dry weather. In rainy weather, the contribution of sanitation through CSO is extremely variable depending on the hydro-climatic conditions (<1% to over than 50%). This work has led to provide usable results for the sanitation manager to optimize CDAPP wastewater treatment. Moreover, this work provides most fundamental results for a better understanding of the hydrological and physicochemical dynamics of urban wastewater and associated pollutants such as highlighting, using statistical tools, the parameters influencing pollutant concentrations during rainfall events.

This project proposes a new urban aquifer strategy that utilizes stormwater to create a cascading plaza and an improved 'great street' in Washington DC. A system of urban aquifers is developed beneath the surface of the street, perched atop the compacted, impermeable soils below. This set of aquifers prevents stormwater from entering the existing combined sewer and allows trees to draw water from this new groundwater source and develop expansive root systems. On the surface, stormwater flows through interconnected planters where it irrigates and is filtered by vegetation before infiltrating to recharge the aquifer. At Cascade Plaza, sloping topography intersects the aquifer, and the new groundwater seeps out of the plaza steps, turning them into a miniature cascade, by gravity and water pressure alone. It collects in a web of runnels, pools at the lowest point, and overflows in high water, mysteriously disappearing below ground again to fill an underground reservoir. In this unique ecological system, water flows both above and below ground to mitigate excess stormwater and make the street and plaza more beautiful. / Master of Landscape Architecture

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Timothy Keane / Kansas City’s outdated sewer system is presently incapable of capturing and treating the increased runoff volumes in Turkey Creek Basin during rainstorm events. As a result, 2.66 billion gallons of untreated sewer system overflow is released annually into the Kansas River and nearby properties. In 2002, the Environmental Protection Agency issued a civil action requiring the City of Kansas City, Missouri, to take appropriate and necessary actions needed to prevent or minimize the discharge of untreated sewage. In response, the City of Kansas City adopted a comprehensive Overflow Control Plan intended to reduce sewer system overflow volumes in Turkey Creek Basin by 85% at a cost of approximately $244 million. Initially, the City of Kansas City seriously considered implementing stormwater best management practices (BMPs) in place of sewer system improvements. Stormwater BMPs infiltrate, filter, store, and evaporate stormwater runoff close to its source, preventing stormwater runoff from reaching the sewer system. Subsequently, many BMPs were eliminated from the Overflow Control Plan and replaced with conventional sewer system technologies because of performance concerns. However, the Overflow Control Plan acknowledged that BMPs located on private property would indirectly benefit Kansas City’s stormwater management strategy. Using geographic information system (GIS) analysis, suitability maps were generated for twelve different BMPs to determine suitable locations in Turkey Creek Basin for reducing stormwater runoff. Analysis concluded that the most effective strategy for sustainable stormwater management would be to locate BMPs at higher elevations within the watershed to prevent upland runoff from flooding sewer system pipes at lower elevations. Areas having the highest suitability are located primarily on residential land, implying that Kansas City could benefit most from encouraging its residents to equip their properties with site-appropriate BMPs. This can be achieved through educational initiatives, policy adoption, and homeowner incentives. Therefore, policies and incentives targeting Kansas City’s residents should be implemented to reduce sewer overflow volumes and prevent future costly improvements to Kansas City’s sewer system.