The national capital has 17 Sewage Treatment Plants (STPs), which together add up to 40 per cent of the total installed sewage treatment capacity in India, but these STPs remain grossly underutilised. Besides, the city does not have the drainage to convey all its excreta to the treatment plants.
While the Yamuna’s 22 km stretch in Delhi is barely 2 per cent of the length of the total river basin, it contributes over 80 per cent of the total pollution load in the entire river. These are the major factors behind the pollution overload in the city’s lifeline Yamuna, according to a Centre for Science and Environment (CSE) report.
Even though Delhi has already spent over Rs 1,500 crore for cleaning the river, the pollution load has only increased, it said. An analysis of the Biological Oxygen Demand (BOD) of the river indicates that nothing has changed in terms of pollution load. “The load has gone up from about 129 tonnes per day in 1982-83 to over 261 tonnes per day in 2019,” it said.
Highlighting on the major factors behind the problem, it said that a majority of Delhi lives unconnected to underground drainage or lives in unauthorised and illegal colonies. The untreated sewage from these areas flows into open drains in which the STPs dispose of treated effluent.
“In this pollution scheme, the illegal unconnected waste of the majority is being mixed with the treated waste of the minority. The result: growing pollution in the river. We can never clean the Yamuna until we can treat the sewage of all in the city. But this will require providing drainage to all, and sewage treatment for all,” said the report.
All governments are designing systems that one cannot pay for, the report said. “These are unaffordable systems to pipe water across long distances, which add to the cost of distribution and worse, increase water loss. Then, we design to take back the waste and pump it and pipe it even longer distances. Thus, there is a need to relearn the science and art of river cleaning,” it said.
As per the 2018 estimates, Delhi has spent over Rs 1,500 crore for cleaning the river, excluding the cost of the CETPs. This is possibly the highest amount spent on river cleaning in India, it said. In 2005, the Rs 380-crore Yamuna Action Plan-II was sanctioned for Delhi.
Capital investment to clean Delhi stretch of Yamuna
- Rs 17 crore: Yamuna Action Plan (YAP) -1
- Rs 163 crore: YAP-Extended
- Rs 750-1000 crore: 17 STPs with a capacity of 2330 MLD
- Rs 256 crore: 15 Common Effluent Treatment Plants (CETPs)
- Rs 100 crore: Sewer Rehabilitation
- Rs 1286 -Rs 1536 crore: Sub-total till 2005
- Rs 2454 crore: Interceptor project (proposed)
- Rs 3740 – Rs 3990 crore: Total for 22km of Yamuna