Old mines are full of exposed chemicals like arsenic and cadmium. Mines are also often close to water sources, and cleaning the surrounding water from toxic contamination can seem like an insurmountable task. Now British researchers are testing a way to clean heavy metals from the water by using algae that will hopefully produce biofuel as a byproduct. Though the project is still in its early stages, researchers hope this could be an inexpensive way to treat contaminated mines around the world.