Sewer exfiltration and the colmation layer
Ellis, John Bryan and Revitt, D. Mike and Vollertsen, Jes and Blackwood, David J. (2009) Sewer exfiltration and the colmation layer. Water Science and Technology, 59 (11). pp. 2273-2280. ISSN 0273-1223
Full text is not in this repository.
Official URL: http://dx.doi.org/10.2166/wst.2009.271
This item is available in the Library Catalogue
Sewer rig studies demonstrate a rapid exponential decline in exfiltration rates from gaps and joints to establish an ultimate steady-state equilibrium varying between 10-3 – 10-6 l s-1, with minimum average daily rates per standardised leak area and sewer length varying between 0.02 – 9.0 l d-1cm-2 and 0.0002 – 2.0 l s-1 km-1 respectively. These loss rates are much larger than those derived from indirect monitoring/modelling studies which suggest losses between 1.4 x 10-5 – 0.179 l s-1 km-1. The confusion regarding conflicting definitions of the colmation, transition, bridging and biofilm layers is addressed, and the significance of these clogging layers in terms of both hydraulic and matrix potential on the exfiltration loss is evaluated. The influence of variability and instability of flow and bed turbulence on determining critical leakage conditions following the onset of equilibrium steady-state is assessed. This challenges the generally held assumption that elevated head pressure condition alone is a necessary precursor for rupture of the clogging layers.
|Research Areas:||A. > School of Science and Technology > Natural Sciences|
|Citations on ISI Web of Science:||1|
|Deposited On:||26 Oct 2009 13:30|
|Last Modified:||24 Mar 2015 13:06|
Repository staff only: item control page
Full text downloads (NB count will be zero if no full text documents are attached to the record)
Downloads per month over the past year