Researchers in Sweden have developed an intriguing method for tracking down terrorists and bomb-makers —using sensors placed in city sewage systems to detect bomb-making chemicals.
The technology, called EMPHASIS (for Explosive Material Production Hidden Agile Search and Intelligence System), was developed by the Swedish Defense Research Agency (FOI) and will go into trials next year in various Swedish cities.
Here's a visual of how it works:
Most effective in urban areas, the system places sensors in various parts of the sewage system and around the city.
When bombs are made, explosives and precursors are released into the air and the sewage system. This can occur either from released fumes, from bomb-makers directly dumping chemicals into drains, or even from the bomb-maker’s bodily waste, which often contains trace amounts of the chemicals they’ve been working with.
The electro-chemical sensors track the concentration of such chemicals in the air and sewage. Sensor data is automatically analyzed and processed, and, if an elevated level of materials is detected, the data can show where the materials are coming from. The sensors are so precise that they can track even trace amounts of suspect chemicals.
The technology is still in the testing phase. It is being jointly funded by the European Union, so it could someday be implemented on a large scale.