Imagine if showering was a luxury, washing your floors a dirty secret, and shampooing the dog was illegal. It isn’t unthinkable that within our lifetimes, bath will be a dirty word as the world grows ever shorter of water — to drink, to wash and crucially, to irrigate crops.

Enter the Israeli startup Aqwind, which has taken the lowest life-forms in the world, bacteria and algae, and harnessed them to a low-cost way to clean dirty water enough for irrigation.

Manure is great as fertilizer, but irrigating with raw human sewage will just produce fruit & veg chock full of goodness, and intestinal bacteria, parasites, and viruses.