Yamuna pollution: Artificial wetland to naturally treat Kondli drain to be ready by November

Noida: The Uttar Pradesh irrigation department has started work on the creation of a wetland to naturally clean stinking murky water of Kondli drain, a major source contributing to the pollution of river Yamuna.

About 500 metres in length, the wetland is being built between sectors 51 and 52 and will be ready by November this year, officials said on Monday.

The Noida authority, which is financing and monitoring the project, said that six more such wetlands will be created at different locations. “The wetland is being built where the drain is the widest. The estimated cost of the first wetland is ₹7 crore, and all seven may cost around ₹42 crore. The first wetland is likely to be ready by November,” said RP Singh, deputy general manager (waters), Noida authority.

In February last year, the National Green Tribunal (NGT) had ordered in-situ treatment of the Kondli drain jointly by the UP irrigation department and the Noida authority, in consultation with Delhi University professor emeritus CR Babu. In continuation to the NGT order, the authority had proposed to create six wetlands at different sites of the drain that cuts Noida into two parts and finally merges with the Yamuna at Sector 168.

“The drain was originally intended as a flood water drain that would also help with irrigation. As the city grew, the drain was fed with untreated sewage. We hope that the artificial wetland will work by decreasing the biochemical oxygen demand (BOD) levels and increasing the dissolved oxygen in the drain water,” said VK Singh, assistant engineer, UP irrigation department.

According to Prof CR Babu, the wetland being built is unique as it aims in-situ remediation of effluents. “We have successfully treated sewage using the wetlands at a Delhi biodiversity park and elsewhere. For Kondli, it’s for the first time the wetland is being built over or on the site of the drain, thus it will lead to in-situ remediation of the effluent. It will be 100% successful in treating even the industrial effluents. However, we will need all seven wetlands to completely clean the drain,” said Babu.

An engineered wetland used to treat the sewage using natural resources including flora and fauna, Babu explained that the wetland will incorporate 25 to 30 species of plants, layers of stones and boulders and two zones. The first zone is for oxidation, where microbes will decompose pollutants and benthic fauna such as snails will eat coliform or bacterial pollutant, while the second zone will be the physical filter zone where stones will provide turbulence and increase oxygen levels, he said.

Various studies, conducted over the years, have identified the sewage in Kondli drain to be the main cause of pollution in the Yamuna. According to a Central Pollution Control Board report, about 64 MLD untreated sewage in Noida flows through the Kondli drain into the Yamuna.

The 40-year-old and 20km long Kondli drain originates from Kondli village in Delhi and enters Noida (via Ghaziabad) near Hari Darshan police post in Sector 11. After travelling through Noida sectors 11, 12, 22, 50, and 92 for about 17km, the drain empties into the Yamuna near Chak Mangrola in Sector 168.