Water and sewerage companies need to identify misconnections of foul water to surface water drains. These are often on customer premises and due to domestic appliances. Tracking down the source of contamination involves an expensive process of repeat site visits to retrieve, read and relocate samplers and instruments.
There is a need for a method that can identify the presence of foul wastewater with a single opening of a manhole.
The UK water companies spend an estimated £190m per annum identifying misconnections (UKWIR, 2012). An effective single entry foul water detection method could be expected to reduce this cost by as much as 30%.
The project will work with suppliers to investigate and evaluate available methods for detecting the presence of washing machine and dishwasher effluents in surface water flows. These would include among others:
- Optical non-contact detection of optical brighteners using a ‘point and press’ device.
- On-site analysis of biofilm collected from non-entry manhole access cover.
- Electronic nose detection of indicator substances, e.g. perfumes.
The output will present different methods for detection with technology recommendations, and a fully costed business case for implementation.
The best way to improve the efficiency of mis-connection identification is to provide reliable, single opening detection method for operators to track down the offending properties. This capability will reduce the time taken and the number of visits required to identify the source of contamination. Depending on the technique, it could also improve the detectability of intermittent discharges.