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