FIELD-TESTING OF HYDRAULIC TRANSIENTS FOR LEAK DETECTION AND MICROBIAL
INTRUSION IN WATER SUPPLY
A joint proposal of Imperial College and Exeter University
Imperial College: Prof. N. Graham (Principal Investigator; Prof. D. Butler
(Co-Investigator); Prof. C. Maksimovic (Research Fellow); Prof. B. Karney
(Visiting Academic, University of Toronto)
Exeter University: Prof. D. Savic (Principal Investigator), Prof. G. Walters
(Co-Investigator) and Dr. Soon-Thiam Khu (Co-Investigator); Dr Zoran Kapelan
(Research Fellow)
The proposed research programme will extend the INVERSE TRANSIENT METHODOLOGY
for leak detection and quantification to WATER DISTRIBUTION SYSTEMS. The
inverse transient technique combines a transient solver with an optimisation
model and involves pressure measurements during a transient event in a pipeline. Inverse mathematics is then used to compute the parameters (pipe
roughness) and the state of the system (leaks). The methodology has been
validated in a pipeline (both in the laboratory and field) but NOT in a NETWORK
which requires an extensive Field Testing Programme using a sophisticated data
acquisition system. The field tests will provide a unique set of data which
will be used to develop a precise solver for modelling hydraulic transients in
distribution networks and to extend and validate the developed inverse transient methodology for leak detection in distribution systems. Leaks are not
only a waste of water, they are also pathways for a contaminated water to be
drawn back into a water supply system.
The second main goal of the research
programme will be to validate the occurrence of low and negative pressures in
distribution systems as a result of hydraulic transients that can cause pathogen intrusions in a water supply system. Laboratory data from the existing
pipe rig at Imperial College will be used to quantify the volume of a possible
intrusion. These data together with the results of the transient solver for
sub-atmospheric pressure levels will be used to quantify potential intrusions
in a water supply system.
The main objective of this proposal is to improve and validate existing
hydraulic transient solvers for their use in water distribution systems (WDS)
by extensive field data collection and numerical validation. Two major
applications of transient solvers will be carefully explored:
(i) leak
detection and quantification;
(ii) prediction of negative pressure events
in a distribution system which can potentially cause microbial intrusion.
Specific objectives are:
1. To expand and validate the developed inverse transient method for leak detection and quantification into water distribution networks (WDN). This will include
(i) EXTENSIVE FIELD TESTS of hydraulic transients in WDN by using a
high number of measurement points with a high frequency of data acquisition;
(ii) Resolving modelling issues such as dissipation of hydraulic transients in
distribution networks;
(iii) Considering sources of uncertainty in modelling hydraulic transients in
WDN;
2. To validate the occurrence of low pressures in WDN that occur as a result of
hydraulic transients and can cause pathogen intrusions. This will include
(i)
To use the FIELD TESTS to validate the occurrence of low pressures in
WDN;
(ii)
To perform experimental tests at the existing pipe rig at IC to quantify the
volume of a possible intrusion;
(iii) To validate the developed transient solvers for modelling the occurrence of sub-atmospheric pressure both in laboratory and
WDN;
(iv) To quantify potential intrusions associated with various transient conditions in WDN;
(v) To provide operational advice with
respect to transient control so that the water companies can develop control
strategies for protecting the distribution systems from pathogen intrusions due
to hydraulic transients.
