A rather eye-opening article by Marc Herman on takepart.com lists eight cities that are running out of water. These include Tokyo, Mexico City and yes, London. The list is informed by the United Nations World Water Development report released earlier this year, that put the problem down to human activity and recommended several tactics for combatting the shortage.
There are several ways that cities can alleviate the pressure on water supplies. Rainwater capture for example, is used extensively in Tokyo, and there is also the option of desalinisation, a technique whereby steam is created from salt water, effectively removing the salt content when it is re-condensed. Although creating drinking water from the seemingly infinite volumes of salt water on this planet would seem like the solution to all of our water shortage problems, the amount of energy required for the technique to work renders it unsustainable due to the cost of fuelling the process. As a result desalinisation is only used in countries such as Saudi Arabia and the Gulf States, where oil is still cheap.
But what about London? According to the UN report we must find new water sources by 2025, earlier than the rest of the world, if we are to continue supplying drinking water to a rapidly expanding population. Once again, the prospect of “toilet-to-tap” is very much on the table.
We pointed out in a previous post that although officially we do not drink recycled wastewater, the water that we do drink is often originally taken from natural watercourses where, further upstream a wastewater treatment plant is discharging its effluent. Indeed if you live in London, your water has on average been through ten other people before it flows through your taps.
Although drinking recycled sewage is not particularly palatable, the wastewater treatment industry has the technology available to them to make it possible. One look at Plantwork System’s NUTREM technology, for example, shows just how thorough wastewater treatment techniques have become.
According to the UN we have until 2025 to find a cure. With oil prices rising and the continued unpredictability of our weather it looks highly likely that the country will be looking to the wastewater treatment industry for solutions to future water shortages.