Inflow/infiltration (I/I) and infiltration/exfiltration (I/E) are interactive processes which dynamically affect sewer and groundwater performance. The incidence and condition of "critical" sewers in the UK are identified together with methods of quantifying I/I and I/E as well as their impact on wet weather sewer performance and on urban groundwater pollution. Whilst the impacts of sewer trenc...

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...

Separate sanitary sewer systems are designed to convey sewage waste from municipal areas to a central treatment facility; they are not designed to handle water associated with precipitation events. However, intercept of groundwater (infiltration) and of flows through manholes or unauthorized connections (inflows) introduces rainwater into the sanitary sewer system. Infiltration/Inflow (I/I) inc...

Extreme climate events are becoming more intense in Melbourne in recent years. This increasing intensity of excessive rainfall has an adverse effect on the sewer network by causing sewage overflow hazards. Extreme rainfall events increase flow into the sewer system, both directly (inflow) and through infiltration into sewer. As a result of this Rainfall Derived Infiltration and Inflow (RDII), S...

various methods have been used to economically design wastewater and stormwater collection systems. in this article, discrete differential dynamic programming (dddp) which is a subsection of dynamic programming (dp) was used. for each pipe network, various alternatives such as depth and slope of pipe laying and various diameters could be considered to satisfy hydraulic and engineering constrain...

The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of s...