The vast, foul-smelling lake lies just above the Palestinian village of Beit Lahia in the northern Gaza Strip. It covers a surface of more than 280,000 square metres and is up to six metres deep, filled to the brim with the barely treated overflow of the local sewage plant.

For years, the plant has been struggling - and failing - to recycle the waste water from households across the northern Gaza Strip. Stretched to the limit, the dam of a separate sewage basin at the site broke in March this year; the flooding killed five people.