116 pollution hotbeds along Delhi’s drains choking Yamuna
The Yamuna pollution monitoring committee — appointed by the National Green Tribunal — has identified 116 locations across the city, which are hotbeds for debris and solid waste dumping.
The committee has submitted its report to the green court. The 116 spots are located along the city’s 22 major drains, including Barapullah, Najafgarh, Supplementary (constructed as supplementary to Najafgarh drain to carry excess flow of water) and Shahdara, among others, that empties into the Yamuna. The committee has asked agencies to conduct intensive patrolling along the spots.
According to the report, a bulk of the waste include plastic waste, polythene, used batteries, cloth and discarded medicines as well as construction and demolition (C&D) waste. The committee in its report has noted the threat the high pollution poses to the Yamuna.
“Untreated domestic sewage is flowing through storm water drains because of the incessant dumping by individual households, unauthorised colonies, slum clusters. Debris are being dumped in the drains by construction agencies, both private as well as government,” said RS Tyagi, former member of the Delhi Jal Board (DJB) and part of an expert team appointed by the monitoring committee.
“At many places near the drains, holes have been made in the boundary walls that were constructed to prevent dumping. Also because of the lack of garbage collection mechanism in unauthorised colonies, people are dumping waste directly into the drains,” Tyagi added.
According to experts, these 22 drains discharging sewage into the Yamuna are the major source of pollution in the 22km stretch between Wazirabad and Okhla.
“In downstream Wazirabad, the Yamuna is just an open sewer carrying a mix of treated and untreated sewage. The 22 drains discharging this mix is one of the major causes of pollution in the river. Najafgarh drain, which discharges around 220 mld (million litres per day), accounts for the highest pollution load (of 67%) of all drains in the river,” said CR Babu professor emeritus and head of the Centre for Environmental Management of Degraded Ecosystem (CEMDE) at Delhi University. He is also helping the Delhi government in restoring the wetlands at the Yamuna floodplains.
While treated sewage has 30-50 mg/litres Biochemical Oxygen Demand (BOD), untreated sewage has 80-150 mg/litres BOD, which means there is no oxygen for the river to sustain and it is biologically dead on this stretch, he added.
High BOD levels indicate polluted water. It means Dissolved Oxygen is consumed by bacteria when large amounts of unwanted matter from sewage or other discharges are present in the water.
“On this 22km stretch, downstream of DND flyover, about 10 drains flow into the 120 hectares of wetlands in the Yamuna floodplains, turning it nearly dead. There is no aquatic life here,” said Babu.
As per NGT norms, a fine of ₹50,000 is to be levied for dumping construction and demolition waste in the river or in the open. For dumping of domestic waste, the fine is ₹5,000.
“Sewage from unauthorised colonies (which do not have sewerage network) is still being discharged into the storm water drains. We visited the area from Mukarba Chowk to Okhla and found untreated sewage being discharged into the drains. Leachates from solid waste and other such materials degrades the quality of water in the river,” said professor SK Singh, head of department of environmental engineering, DTU, who is one of the expert members in the team.
According to Manoj Misra, convener, Yamuna Jiye Abhiyan, natural drains of around 80-100 feet and above have a lot of biodiversity, with different kinds of plants and animals including reptiles. “We have to look at these drains as small rivers, rich with biodiversity, which is destroyed by dumping of solid waste and debris. The waste obstructs the flow of the drains and reduces its carrying capacity. For instance Najafgarh drain used to be a channelled course of Sahibi river, which over the years has turned into a drain because of floodplains and width being reduced,” said Misra.