Solid Transfer in Low Flow Sewers, the Distance Travelled So Far Is Not Enough

Sewer blockages are on the increase whilst water closet (WC) flush volumes
are on the decrease. Furthermore, Water UK reported figures show that the
actual number of properties affected by sewer flooding is on the rise. Sewer
blockages can lead to sewer flooding of homes and collapse of sewers which
impact negatively on social, economic and environmental factors, and therefore,
they are not sustainable. Water conservation is required due to water
stress but reduced water use results in less water to waste, which in turn reduces
solids’ transfer in sewers. When considering reducing water usage
through water conservation, these savings could be cancelled out by an increased population and the situation exacerbated by the impacts of climate
change. There are issues in relation to varying design methods, a reliance on
engineering judgement in sewer design, uncertainty relating to future water
stress, and a lack of cross disciplinary design decision-making. Public health
engineering solutions are needed to reduce the number of sewer blockages
and the environmental impact of sewer flooding. This paper examines the
fundamental research that have been carried out in the area of “solid transfer
in sewers” resulting from “less water to waste” since the mid-20th Century.
Contrary to existing literature, this paper identifies that, now more than ever,
this type of research is needed to deal with the increased need for water conservation. To judge that solid transfer research is complete can be compared
to supporting a statement that “water conservation is complete”.