The Mayor’s proposal for all new households to have food waste crushers may ease the burden on the city’s tottering garbage management system, but will the sewerage network, which is already under stress, be able to manage the additional load?
Sarfaraz Khan, Joint Commissioner (Solid Waste Management), Bruhat Bengaluru Mahanagara Palike (BBMP), said he first saw a food waste crusher being used in Dubai and bought one.
“It is one of the most effective ways of handling food waste in the kitchen. There is neither any smell nor any fuss over the waste. Even meat and bones are finely pulverised in the crusher. The resultant slurry is thin and will not lead to clogging of the drain,” he said, and added that the Sewage Treatment Plants (STPs), where the slurry will eventually end up, can easily treat it, as it has no toxins or metals.
The Bengaluru Water Supply and Sewerage Board (BWSSB), too, is confident that existing STPs are up to the job. Kemparamaiah, engineer-in-chief, BWSSB, told The Hindu that since the waste is crushed and let in as a thin slurry, it will not clog the sewage system. “In many cases, we find people throwing solid waste into drains, clogging them. This is far better,” he said.
However, S. Vishwanath, water conservationist, is more cautious. “Most countries in the West have a constant water supply, unlike here, where many areas get water once in four days. Moreover, if users flush oil and other fats through the sink, it will eventually not only clog the pipes, but also end up wreaking damage on the STPs,” he said.
He argued that all wet waste should be either composted or treated at a biogas plant and a food waste crusher should be a ‘weapon of last resort’. “Bengaluru is not yet ready for a food waste crusher,” he said.
How the crushers work
An electric wet grinder-like equipment fitted next to a kitchen sink, pulverises food waste and turns it into a thin slurry with water.
The slurry is flushed down the sink and let into the larger sewerage network. Such crushers are commonly employed across most European countries, the U.S. and Japan.
