Water, Sewage & Effluent November-December 2017 | Page 28

South Africa has historically managed water very poorly, despite it being in the top bracket of dry countries worldwide. To the last drop Increasingly, the world is researching ways to obtain the last drop of potable water out of everything, from recycled water to human waste – with differing results. By Kim Kemp 26 T he word ‘wastewater’ is inclined to leave a bad taste in one’s mouth as it is generally viewed as a by-product and something to be discarded. Yet increasingly, the public is moving past this perception, and turning wastewater into potable water is gaining traction, easing the strain of accessibility to this resource in water-scarce countries. Wastewater definition Wastewater comes from a combination of domestic, industrial, commercial or agricultural activities; from ordinary living processes, including bathing, toilet flushing, laundry, dishwashing, and so on. It Water Sewage & Effluent November/December 2017 can originate from surface runoff or storm water, as well as from sewer inflow or infiltration. As a rule, wastewater is broken into two categories, depending upon the source: Greywater: is from sinks, washing machines, and bathtubs. It contains lower levels of contaminants than blackwater and is easier to treat and process. It can even be used directly in gardens, if there are no harmful chemicals present, like soap and detergents, that can harm the plants and the soil. Recycled greywater can also be used for irrigation and in constructed wetlands. If the greywater is from the sink, food