However, sanitation experts and various studies — including those commissioned by the railways — have pointed out that most of the new “bio-toilets” are ineffective or ill maintained and the water discharged is no better than raw sewage.
A new kind of toilet using bacteria to break down human excreta has been deployed in Indian trains over four years to 2017, at a cost of Rs 1,305 crore, but this toilet is no better than a septic tank, the Indian Institute of Technology-Madras (IIT-M) has concluded after a two-year long study.
As many as 93,537 “bio-digesters” — as the toilets are called –have been installed in mainline express and mail trains by the Indian Railways. These are small-scale sewage-treatment systems beneath the toilet seat: Bacteria in a compost chamber digests human excreta, leaving behind water and methane. Only the water, disinfected later, is let out on the tracks.
“Our tests have found that the organic matter (human waste) collecting in the bio-digesters do not undergo any kind of treatment,” IIT professor Ligy Philip, who headed the latest study, told IndiaSpend. “Like in the septic tanks, these bio-digesters accumulate slush (human excreta mixed with water).”
The IIT-M study was sponsored by the Bill and Melinda Gates Foundation and submitted last week to the Union Ministry of Urban Affairs.