The National Research Council Canada (NRC) has recently completed a project to assist the City of Montreal in determining the condition of its water and sewer system. NRC staff members reviewed available and developing diagnostic techniques for both systems, conducted experiments on non-destructive evaluation methods and provided general scientific advice during the course of the project. This ...

Lake Utterslev is situated in a densely built-up area of Copenhagen, and is heavily eutrophicated from combined sewer overflows. At the same time the lake suffers from lack of water. Therefore, a 5,000 m2 vertical flow wetland system was constructed in 1998 to reduce the phosphorus discharge from combined sewer overflows without reducing the water supply to the lake. During dry periods the cons...

An automated algorithm based on the dynamic hydrological and hydraulic simulation modules in Storm Water Management Model (SWMM) was developed to aid the design of storm sewer networks, provided that a layout is given. Numerical performance of the proposed algorithm was compared with the existing design methods with two application cases. The automated computation process of the sewer network d...

The nature of trace element carriers contained in sewage and combined sewer overflow (CSO) was investigated by TEM-EDX-Electron diffraction and SEM-EDX. During dry weather, chalcophile elements were found to accumulate in sewer sediments as early diagenetic sulfide phases. The sulfurization of some metal alloys was also evidenced. Other heavy metal carriers detected in sewage include metal allo...

Asset management is an increasing concern for wastewater utilities and companies. Indicators are developed for supporting the definition of investigation and rehabilitation programs. These indicators are mostly based on visual inspections, which provide major information. However, difficulty remains in the translation of a visual inspection survey into dysfunction indicators. Condition grade of...

To understand wastewater quality transformations in the sewer system, a full-scale study focused on the characteristics of the influent wastewater in a middle-sized wastewater-treatment plant receiving only municipal sewage. The objective was to identify conditions in which prefermentation prior to the biological nutrient removal (BNR) process would be useful. Prefermentation aims at increasing...

We simultaneously determined the phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria (SRB) inhabiting a sewer biofilm with oxygen, nitrate, or sulfate as an electron acceptor by combining microautoradiography and fluorescent in situ hybridization (MAR-FISH) with family- and genus-specific 16S rRNA probes. The MAR-FISH analysis revealed that Desulfobulbus hybri...

Most biological systems employ visually acquired information for their locomotion. In the course of evolutionary history, the visual system of organisms has evolved to he adapted to the environment. As a consequence of this adaptation, biological systems often display highly efficient visual skills. This reasoning has motivated the development of a specific visual system, which serves the purpo...

The city of Toulouse with its separate sewer system is ideal for studying stormwater. However, during dry weather, the storm sewer also discharges water into the environment, and it is the impact of these discharges on annual pollution from storm sewer that is the object of this study. Samples have been taken from the outlets of two storm drains located in heavily and moderately urbanized areas...

It is widely recognised that flood risk needs to be taken into account when designing a storm sewer network. Flood risk is generally a combination of flood consequences and flood probabilities. This paper aims to explore the decision making in flood risk based storm sewer network design. A multiobjective optimization is proposed to find the Pareto front of optimal designs in terms of low constr...