Utilities have invested heavily in upgrading Combined Sewer Overflows (CSOs) to meet stringent discharge requirements to inland, estuarine and marine waters. Spills from CSOs need to be monitored to demonstrate compliance and, in the case of discharge to shell fishery waters, as an ongoing requirement under the European Shellfish Hygiene Directive (91/492/EEC).
There are some spill sensors of the float-on-an-arm type and manufacturers are beginning to provide low power, explosion protected non-contact sensors such as ultrasonic level types which may offer greater reliability. Mains powered, hard wired telemetry CSO monitors are an expensive route to meet monitoring obligations. Savings of several thousand pounds per installation can be made using battery powered systems with wireless telemetry.
This project will examine available equipment and some possible alternative sensors, carry out a 3 month trial of a commercial float and a non-contact system and provide guidelines for CSO spill monitoring equipment. Equipment will need to comply with the European ATEX Hazardous Area Protection Legislation which comes into force in July 2003.
- Ability to meet Regulator and Directive (e.g. Shellfish Hygiene and ATEX Hazardous Area Protection) obligations and monitoring.
- Assurance of reliable CSO data at lowest cost with up-to-date technical information on available equipment.
- Assurance of correct CSO use with design and installation guidelines for different CSO types.