CP404 Disinfection Forum
DWI requires water companies to establish site specific regimes to meet regulatory microbiological quality after treatment, and operate distribution systems to maintain this quality up the customers tap. This requires a risk based approach to identify disinfection requirements, based on the expected microbiological load, and the implementation of appropriate disinfection systems to deal with the challenge. Selection of suitable technologies, and appropriate design and operating conditions, are critical elements in meeting these disinfection requirements. Maintaining awareness of these technologies and practices will help disinfection targets to be met efficiently at lowest cost. WRc is carrying out work for a consortium of Water Utilities under its Portfolio collaborative research programme to disseminate information on disinfection and sharing experience, through:
- structured meetings between participants,
- reviews of research and developments in disinfection technology and implementation.
This will allow the participants to identify:
- the most appropriate disinfection technologies and operating conditions to meet regulatory requirements for microbiological quality,
- potential operating problems and ways of overcoming these,
- developments in technologies and regulatory approaches with potential benefits or impact in the medium to longer term.
Meetings, held three times a year, will have particular themes which will be agreed in advance, and could include, for example:
- Microbiological risk assessments and their interpretation for disinfection design and operation
- Tracer tests and contact tank design/operation to define effective CT (chlorine concentration x time)
- Design and operation of UV systems
- Chlorine dioxide
- By-product concerns
- Monitoring and control e.g. triple vs dual validation
- Role of alternative disinfectants e.g. chlorine dioxide
- Dealing with coliform failures
- "Secondary disinfection" - the role of disinfectant residuals in distribution
- Maintaining security of supply for chlorine, hypochlorite quality, alternative disinfectants.
A summary analysis of issues, current research and regulatory perspectives will be sent out before each meeting to form the basis for presentation and discussion at the meeting. A “state of the art” report on each meeting will be circulated to participants, which will review the issues identified, summarise the discussions at the meeting, provide recommendations on technology and operating practices, and identify outstanding questions or gaps in the knowledge.
If you are interested in joining the forum, please contact Tom Hall for further information.