Sewer sensors could help identify drug and explosives labs

New Scientist : A €4.5 million research project funded by the European Union aims to deploy chemical sensors in sewers to look for trace evidence of drug and chemical manufacturing, which can leak into the sewage system through toilets and sinks. The Emphasis project, led by Hans Önnerud of the Swedish Defense Research Agency in Kista, uses ion-selective electrodes that are submerged in flowing wastewater to detect specifically the ionized products of the breakdown of chemicals used in bomb making. The system has been successfully tested in the lab and will be tested in real sewers next year. Önnerud says that the project was initiated after the 7 July 2005 London public transport bombings, when it was discovered that chemical fumes killed plants around the house in which the explosives were prepared. A fully operational system could also be used to monitor traces of illegal drugs in wastewater. However, maintaining the sensors could be difficult in sewer systems that also transport solid waste, which could block the sensors.