Using these techniques, they are allowing nature to do the work, so it breaks down waste using no to little energy. Traditional wastewater treatment often needs chemicals and a lot of power, while natural green systems depend on bacteria, plants and soils and the power of the sun- basically using nature. Better still, these wetland systems using no or little energy – prevent the CO2 emissions & pollution from burning fossil fuels to make electricity, so they can generate carbon offsets.