A major drawback of separate sewer systems is the occurrence of illicit connections: unintended sewer cross-connections that connect foul water outlets from residential or industrial premises to the storm water system and/or storm water outlets to the foul sewer system. The amount of unwanted storm water in foul sewer systems can be significant, resulting in a number of detrimental effects on t...

Hospital effluents can potentially increase the concentration of emerging pollutants in the influent of wastewater treatment plants (WWTP) and receiving water bodies. This paper presents a hydraulic model that predicts the transport of selected pharmaceuticals and personal care products (PPCP) in a municipal sewer system section of Oslo, Norway. The sewer section additionally collects sewage fr...

Prolonged drought which has occurred everywhere around the world has caused water shortages, leading many countries to consider more sustainable practices, which are called source management practices (SMPs) to ensure water availability for the future. SMPs include the practices of water use reduction, potable water substitution and wastewater volume reduction such as water demand management, r...

This paper addresses the problem of navigation of an autonomous robot when it moves in a modern concrete sewer. The robot must keep its orientation within mostly cylindrical sewer pipes. This implies a geometrical constraint on the environment in which the robot operates. We present a hybrid vision system that consists of (a) an optical camera and (b) a laser crosshair projector generating a cr...

Concrete corrosion is one of the most significant problems affecting valuable sewer infrastructure on a global scale. This problem occurs in the aerobic zone of the sewer, where a layer of surface corrosion develops on the exposed concrete and the surface pH is typically lowered from around 11-10 (pristine concrete) to pH 2-4. Acidophilic microorganisms become established as biofilms within the...

Biochemical reactions that occur in sewer pipes produce a considerable amount of hydrogen sulfide gas (H2S corrosive and poisonous), methane gas (CH4 explosive and a major climate change contributor), carbon dioxide (CO2 a major climate change contributor), and other volatile substances (collectively known as in-sewer gases). These toxic gases lead to contamination of natural environment, sewer...

The sewer layout in flat areas significantly influences the construction and operational costs as well as reliability of the network performance. To find an optimum design of sewer networks for flat areas, this study presents a multi-objective optimization problem with the objective functions of 1- the cost and 2- the reliability. The reliability criterion is defined as the effect of a clogging...

Underground structures in shales or shaly rocks endure time-dependent swelling effects. Laboratory test results show that the swelling of these shales is dependent on three-dimensional stresses; an external stress on a specimen in one principal direction reduces the swelling not only in that direction but also perpendicularly. The effectiveness of a time-dependent swelling model that considers ...

The Hamburg Water Group owns and operates a sewer network with a total length of more than 5,700 km. There has been increasing attention paid to the possible impacts of predicted changes in precipitation patterns on the sewer network infrastructure. The primary objective of the work presented in this paper is an estimation of the hydraulic impacts of climate change on the Hamburg drainage syste...

To monitor water quality continuously over the entire sewer network is important for efficient management of the system. However, it is practically impossible to implement continuous water quality monitoring of all junctions of a sewer system due to budget constraints. Therefore, water quality monitoring locations must be selected as those points which are the most representative of the dataset...