Like a shimmering oasis the city of Riyadh rises out of the sand.  Located in central Saudi Arabia the capital city is 250 miles from the nearest coast.  Although the Arabian Peninsula is surrounded by water, humans cannot drink saltwater.  Saltwater can be turned into drinking water through a process called desalination however, and desalination is increasingly used as global populations grow.

When my husband and I visited Riyadh in 2012, one gallon of water cost three times a gallon of gas.  We could see why.   The population of the city has grown from 100,000 to over five million in the past century. To supply this precious resource seven desalination plants work to provide about 70% of the potable water for the use of its inhabitants. Desalination is a costly process that takes high energy though, deep underground aquifers and scarce ground water provide the rest.  Our host told us that he had dug a well for a new home that he is building on the outskirts of the city.   When he said that they had to dig 500 feet down to reach water, my husband jokingly asked if they had stuck oil as well. Read the rest of this entry →