Infrastructure Theme: Drinking Water Distribution Systems

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Infrastructure Theme Drinking Water
Distribution Systems
Project 1 Impact of infrastructure management
on the contamination of drinking water with
pathogens Project 2 Protecting the integrity of
drinking water distribution systems Michèle
Prévost and Marie-Claude Besner

• November 24, 2005
• Kananaskis Researcher Retreat

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Overall Goal

• Determination of the likelihood of drinking water
  DS contamination during normal operation and
  determination of the risk associated with OM
  activities

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Research Team

• Key Participants

Project 1 (2002-2005)
Project 2 (2005-2007)
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Key Challenges/Goals

• The Key Challenges Being Addressed by Our Team
  are
• What are the causes of non-compliance events in
  DSs?
• Do OM activities represent a significant risk of
  contamination?
• Controlled pump startup and shut down
• Opening/closing of fire hydrants or valves
• Flushing operations
• Repairs of pipeline breaks
• How are these activities related to the
  occurrence of transient pressures?
• How can DS design and operation be improved to
  minimize the risk?
• What are the economical impacts of repair works
  and water contamination?

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Relevant State-of-The-Research

• Waterborne disease outbreaks are caused by DS
  deficiencies
• Integrity of DS is key Payment studies on DS
• Ingress is possible in pressurized systems
• Contamination is possible during
  repairs/replacement
• Backflow prevention
• Pipe failures in ageing infrastructure are a
  growing concern

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Approach

• Study of the impact of infrastructure
  operation/management on the contamination with
  pathogens
• Data mining
• Field samplings
• Study of the impact of transient low pressures on
  pathogen intrusion

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Stage of Research

• Main causes of non-compliance events have been
  identified through the use of a data-mining
  approach
• Protocols for sampling during some OM activities
  have been developed
• Field investigations of OM activities are in
  progress

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Key Findings/Observations

• Our data mining approach
• showed that water quality problems could only be
  explained by considering various types of data
  (water quality, hydraulics, OM, system
  structural characteristics, etc.)
• This finding has been transposed in our field
  studies by involving experts in all those fields.
  The research team study the physical, hydraulic,
  chemical and microbiological aspects of
  distribution systems.
• DS microbial water quality
• Although microbial regrowth was classically
  associated with occurrence of non-compliance
  events, we showed that OM activities in DSs
  could be a significant cause of these events

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Key Findings/Observations

• This is the first study providing actual data on
  impact of main repairs. Our investigation shows
  that main repairs affect water quality both
  inside and outside the repair area
• Our field investigation methodology led to the
  first demonstration of actual contaminant
  intrusion of microbial indicators into a full
  scale distribution system, during pipe repair
  work.

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Insights on Knowledge Transfer

• The paper Explaining the occurrence of coliforms
  in DSs by Besner et al. (J. AWWA, 2002, 948.
  95-109) was granted the 2004 AWWA Distribution
  Plant Operations Best Paper Award
• The data mining approach (and software) developed
  is being applied in a number of European
  utilities managed by Veolia Water
• USEPA, as part of the TCR revision process, is
  writing a white paper based on our results of
  causes of non-compliance events
• The 2004 AWWA WQTC presentation on field
  investigation of repairs led to the invitation of
  M-C Besner to a 1-day workshop on Pipeline
  repair/replacement practices and their
  relationship to water quality at the 2005 AWWA
  DSS Conference

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Opportunities

• Complete project to get insights into
• Impact of pipe flushing
• Impact of pump operation in rural system
• Risk analysis framework
• Economic analysis of impacts of repair works

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Collaborative Interests

• Development of data mining approaches
• Risk analysis approaches for determining risks
  related to DSs
• Epidemiological studies
• Advanced microbial detection methods