The Future of Bomb Sniffing Is in Shit

An EU-funded project is developing a network of sensors that could sniff out bomb-makers from the substances they flush into sewers. The idea is to catch people who are cooking up their own IEDs before they’re able to use them.

The project is called EMPHASIS, which stands for Explosive Material Production Hidden Agile Search and Intelligence System, and is led by Hans Önnerud at the Swedish Defense Research Agency (FOI). It sets out the objective on its website: “The goal of the EMPHASIS project is to test a system concept for the surveillance tool of tomorrow for detection and localization of illicit bomb factories in urban areas.”

When brewing up your own explosives, you’re likely to wash some of the chemicals used to make them down the drain. The EMPHASIS sensors are designed to detect these tell-tale substances at low concentrations, and raise the alarm for specialized police teams to swoop in. The system is intended for urban areas, where pinpointing the location of bomb-making activity is particularly difficult and requires a lot of manpower. The project notes reference the 7/7 London Underground bombings in 2005, which were carried out using homemade explosives manufactured in a Leeds flat. “The discovery of these types of suicide bomb attacks is very difficult and relies on intelligence and qualified police work,” they explain. “If discovered at a late stage of the criminal activity, it is very hard to neutralize the object without consequences for third person.”

Planting sensors in sewers is in some ways ideal—it’s a citywide network that’s hard to avoid using—but it brings its own, rather unsavory, challenges. Small amounts of bomb-making chemicals would need to be detected through all the other crap (literal and figurative) that gets flushed down the pipes, and the sensors would have to avoid getting too smothered in stinky detritus to operate. New Scientist reports that the EMPHASIS team has successfully tested their sensors in “faeces-rich wastewater” in the lab, and will go on to test them in real sewers next year.

It’s not the first time researchers have turned to sewage to gather data about what people are up to in their spare time. Scientists have used wastewater to track other illicit activities, such as a 2012 study that looked at drug use across 19 European cities (conclusion: people party more at weekends). A study from earlier this year also analyzed sewage to find that half of England’s Tamiflu prescriptions went unused during the 2009 swine flu epidemic.

In addition to the sewer network, the EMPHASIS project looks at using other sensors to detect hints of explosive action. Traces of suspicious gases could be found in the air, for example, and small amounts of substances could be left on surfaces such as door handles. Fusing the data gathered by different detectors would help give a more accurate picture of where to look. “The intention is first to cover a large area that will be reduced step by step to smaller areas,” the project site explains. “The search strategy in the smaller area is to increase the number of sensors used in order to localize the bomb factory.”