Palestinian workers drill water wells, in Gaza city, on June 01, 2014. The coastal aquifer, Gaza's main water source, has been continuously over-pumped for decades, even prior to Israel's occupation in 1967. Some 180 million cubic meters (mcm) are annually pumped from the aquifer, although its rate of replenishment is only 50-60 mcm a year. Over the years, this has significantly lowered the groundwater level, leading to contamination of the aquifer’s water by seawater seeping in and saline groundwater rising from deeper in the reservoir. Photo by Ezz al-Zanoun