New Delhi, Jan. 28 -- The Delhi Jal Board (DJB) will undertake in-situ treatment of five drains and their sub-drains before they empty into the Yamuna. These include the drains at Delhi Gate, ISBT, Defence Colony, Sen Nursing Home, and No. 12A, officials said. Officials said the project is likely to cost over Rs.30 crore, of which around Rs.21 crore will be spent on the Delhi Gate drain, Rs.3.27 crore on Sen Nursing Home and No. 12 drains, Rs.1.41 crore at Defence Colony, Rs.2.09 crore at ISBT and Rs.1.31 crore on Jaitpur drain in southeast Delhi. In-situ wastewater treatment involves treating sewage directly at its source within the drain, using biological, physical, and chemical processes to remove pollutants, rather than transporting it to a centralised facility. Experts, however, say that without resolving the underlying basic issues contaminating drains, the in-situ treatment may turn out to be wastage of money. Bhim Singh Rawat, a Yamuna activist and member of the South Asia Network on Dams, Rivers and People (SANDRP), said that in-situ treatment has also been tried in the Varuna and Assi stretches in Varanasi, but it has not yielded good results. "We have to stop taking the piecemeal approach and experimentation. There are a large number of factors which are at play leading to pollution in drains, varying from sewage to illegal industries dumping chemicals. Things fall apart due to local conditions which ultimately leads to wastage of taxpayers money. DJB should consult citizens, tap drains and make it a participative exercise," he said. According to a Delhi Pollution Control Committee (DPCC) report from December 22, 2025, these drains have high pollution levels. The ISBT drain had total suspended solids (TSS) of 294 units, chemical oxygen demand (COD) of 272 units, and biochemical oxygen demand (BOD) of 115 units-all much higher than standards. The Sen Nursing Home drain recorded TSS at 368 units and BOD at 344 units. The Jaitpur drain had TSS of 120 units, BOD of 180 units, and COD of 70 units. BOD indicates organic pollution by measuring oxygen needed by microorganisms, COD measures total oxygen required for chemical oxidation of pollutants, and TSS indicates turbidity from undissolved components; lower values signify better water quality....