It has been understood for some time that the placing of level sensors at strategic locations within the network can provide sufficient early warning of a growing blockage to permit its clearance before disaster strikes.
For a long time finding a universal technology that could simply report a high level from any location was a challenge. Ultrasonic units coupled to GSM communication devices had been tried for decades but often failed to live up to expectations due to poor power consumption, human errors concerning configuration and in particular intermittent or failed communications. On top of these are also a number of constraints related to the physics of the ultrasonic beam, such as the generation of false echoes from obstructions and spiders webs and minimum reading distances. Finally, there is the uncertainty over the longevity of these assets due to the dash for 4G and 5G by the cellular operators.
In 2010 Radio Data Networks introduced a new radical approach to sewer monitoring that included both a new sensor and a real-time communications strategy that would permit sensors to be deployed anywhere in the networks irrespective of the size of the sewer and the lack of cellular coverage. However, more importantly this system gave the utility the choice of how data was delivered, by offering a wide range of Booster/Repeaters and Data Gateways into existing systems such as telemetry and SCADA via relays, serial data links and more lately via data concentrators connected directly to the internet. Sewer status can also be verified using a handheld data terminal or laptop without the need to open manhole covers.
Today the BDT blocked sewer / drain systems as they are called can be found in service with a number water utilities both in the UK and overseas has have won numerous national awards for its innovation.
Data / messages from BDTs can be delivered using a variety media including our own private data networks, locally via relays to control pumps or to interface with existing SCADA collected by handheld terminals, or delivered via data concentrators to remote data servers and the internet.