Get ready to drink purified water from the toilet! The Delhi government has launched the capital’s first so-called toilet-to-tap water project at the Keshopur Sewage Treatment Plant, which treats raw sewage by a multiple filtration process to convert it into potable water, reports Takepart.
To prove that the treated water is actually drinkable, Delhi Chief Minister Arvind Kejriwal himself had a glass of it. So how does it works? Officials say that the technology used to purify water works the same way as nature.
“Raw sewage is pumped into the five-layered biofilter—comprising earthworms, cotton extracts, bacteria, organic sand, pebbles, stones, etc. This treated sewage is then pumped into the membrane system, where it is chlorinated and made available for drinking purposes.”
Though this project can produce 20 million gallons of drinking water a year, there’s still a stigma attached to the idea, making it difficult for residents to embrace it. A chemical and biomolecular engineer said:
“The term that has been coined, ‘from the toilet to the tap,’ is omitting the fact that there is a lot of treatment in between, so it gives the wrong perception.”
Only three-fourths of Delhi residents have access to piped water and the rest of the population relies on untreated groundwater. Also, nitrate levels in drinking water have been recorded at as high as 1,500 milligrams per liter.
More than half the city’s population isn’t connected to Delhi’s sewage system, and just 15 percent of the population uses septic tanks. As a result, raw sewage flows into the city’s network of unlined storm drains and into the Yamuna River.
Many regions around the world are looking into implementing the idea, including developed countries. Kejriwal said:
“If this project is up-scaled in a decentralised manner, every home will get sewer and water connections in the next three to four years.”