‘Yoda’ for scientists: the outsider ecologist whose ideas from the 80s just might fix our future

John Todd's eco-machine stunned experts by using natural organisms to remove toxic waste from a Cape Cod lagoon. Forty years on, he wants to build a fleet of them to clean up the oceans

John Todd remembers the moment he knew he was really on to something: There was no question that it was at the Harwich dump in 1986," he recalls. This was in Cape Cod, Massachusetts, close to where Todd still lives. Hidden away from the picturesque beaches was the town landfill, including lagoons of toxic waste from septic tanks, which was being left to seep into the groundwater below. So Todd, then a 45-year-old biologist, decided to design a solution. What he was on to", he came to realise, was not just a natural way of removing pollution from water, it was a holistic approach to environmental restoration that was way ahead of its time, and possibly still is.

An early eco-machine purifying toxic waste on Cape Cod in 1986. Photograph: John Todd