A study on the relationship between fat, oil and grease (FOG) deposits in sewer systems and FOG disposal patterns

Fat, oil and grease (FOG) deposits are one of the leading causes of sewer system blockages, thereby increasing the risks of undesired and polluting flooding and sewer overflows. FOG accumulates throughout the entire sewer network; e.g., in public sewer pipes and lateral house connections it reduces the available discharge capacity, and in pump...

Risk based flood management of sewer systems

Traditional sewer flood management is often norm-based. An alternative approach is risk-based sewer flood management. In risk-based sewer management it is possible to decide upon which measures to take in a more expedient way; it is possible to judge which measure is the best in reaching the goal of reducing risks due to flooding. A risk is...

Potentiality of a velocity profiler to investigate sewers: Results of laboratory experiments

In order to propose a new sewer inspection method, a velocity/turbidity profiler (Ubertone, UB Flow F-315) has been tested in a laboratory. A 50 m glass flume has been adapted with several lateral connections (with a range of diameters, angles, intrusions, cracks), supplied by a 1 m3 tank. Placed just below the free surface on a rotating (to...

Detection and quantification of lateral, illicit connections and infiltration in sewers with Infra-Red camera: conclusions after a wide range of experiments

The most known problem of separate sewer systems is the existence of illicit connections and, hence, the deposition of untreated sewage to the receiving waters or the occurrence of urban flooding due to overloading of wastewater systems with storm water. Although there are several known and relative expensive techniques for inspection of storm...

A Study on the Fouling Process in Inverted Siphons over Time

In Amsterdam, over 200 so called inverted siphons are situated. As these siphons are prone for blockages, it is key that these parts of a sewer system are maintained proactively. This article outlines the basis of a methodology that can be used to estimate the fouling degree of sewers with the use of water level measurements. Even though the...

Laser profiling of sewer pipes

The goal of the research is to determine the potential of laser scanning methods for accurate, non-invasive assessment of the changes in the inner pipe profile of concrete sewer pipes. The main research question is: ‘How accurate is the laser profiler when measuring deteriorated sewer pipes?’ In the research egg shaped concrete sewer pipes were...

On the correlation between Turbidity, Conductivity and COD

Introduction COD is one of the most important parameters for wastewater quality. Measuring COD is an expensive and time consuming process. There is a need for an inexpensive, accurate, reliable and continuous technique to monitor COD. Turbidity can be used as a proxy for COD, but is not accurate enough for some applications. Some research...

Notification Registration Procedures in case of flooding: Research and efficiency improvement

Introduction For several years it is known that as a consequence of climate change rain patterns will change in the future. Winters are becoming wetter and summers are becoming drier. Especially in summer period extreme rainfall will more often occur. Extreme rainfall may lead to ' water in the street ' and 'flooding '. ' Water in the street '...

Pluvial flood damage modelling: Assessment of the flood damage model HOWAD-PREVENT

Introduction Flooding is a natural phenomenon, but human activity has significantly altered the natural drainage processes thereby occasionally causing greater flood risk. Urban flooding has become more frequent due to a number of factors including climate change, urban growth and an increase in paved surfaces. Pluvial flooding results from...

Air entrainment with plunging jets: Experimental study about air entrainment with free overfall jets from circular channels and air bubble intake with submersible pumps in sewer sumps

Many pressurized sewer systems do not reach their design capacity discharge due to enlarged resistance in the pipe system. An extensive investigation has brought to light that air pockets in pipe systems are an important cause of high resistance in sewer system pipe lines. Air intake by pumps in sumps is one of the main reasons of air pocket...

Modellering van rioolstelsels tijdens water op straat: Metingen in een schaalmodel

Voor het ontwerp van rioolstelsels wordt gebruik gemaakt van hydrodynamische modellen. Met deze modellen worden stelsels zo ontworpen dat alleen bij buien die eens per 2 of 5 jaar optreden niet al het water wordt afgevoerd. Door deze modellen wordt de waterbeweging in de riolering goed beschreven en het is goed mogelijk om te bepalen hoe vaak er...