Water treatment works use numerous on-line water quality measurements. Those used for control (e.g. chlorine or pH) are duplicated or triplicated to notionally improve reliability. Some used for monitoring, (e.g. metals), suffer poor reliability and expensive maintenance.
Relationships between water quality and chemical dose, (particularly pH and chlorine), could be better exploited to check for consistency between independent on-line measurements and to identify common-mode failures. E.g. comparing chlorine mass dose, (a low cost, but rarely employed on-line measurement), with free chlorine after disinfection highlights treatment effectiveness, contamination or calibration drift.
Using current technology, cross referencing a small number of on-line measurements can provide a highly secure, yet cost-effective, source of information for monitoring / control. This approach offers greater measurement reliability, at less cost than standard multiple measurements and is consistent with risk mitigation (through source to tap monitoring), embodied in Water Safety Plan initiatives from the WHO, Europe and the DWI.
This project will examine how technology for on-line monitoring can be best exploited to minimise costs / maximise security. The whole life costs and risks of alternative approaches will be evaluated and options evaluated at full scale.
- Increased treatment security, through on-line monitoring, consistent with Water Safety Plans' requirements.
- Significantly reduced cost of monitoring.
- Greater understanding of treatment processes, and hence operation, through better process data.