It has been found that 56 per cent or 21 out of 37 sewage treatment plants (STPs) in the national capital fail to meet quality standards set by Delhi Pollution Control Committee.
The water from these STPS eventually finds its way to the Yamuna river which is further utilised by some farmers in the region for cultivating vegetables on the banks of the river.
The STPs that failed the test are situated in Keshopur, Nilothi, Najafgarh, Papuan Kalan, Rohini, Narela, Yamuna Vihar, Mehrauli, Vasant Kunj, Molarband, Okhla and Ghitorni.