New Delhi, May 14, 2025: The water quality of the Yamuna river has significantly worsened, with biological oxygen demand (BOD) levels spiking to over 42 times the permissible limit, according to the latest report from the Delhi Pollution Control Committee (DPCC). This alarming increase in BOD levels has raised concerns over the river’s ability to sustain aquatic life and its overall environmental health.
The report, titled “Progress in Rejuvenation of the River Yamuna,” tracks the BOD levels at key points along the Yamuna between January 2023 and March 2025. The data reveals concerning trends in water quality, with the worst readings recorded downstream of the Shahdara drain, where the river exits Delhi.
Understanding BOD and Its Implications
Biological Oxygen Demand (BOD) is a critical measure of water quality, representing the amount of oxygen microorganisms need to decompose organic material. High BOD levels indicate poor water quality, as they suggest excessive organic pollution that depletes oxygen and harms aquatic ecosystems. The Central Pollution Control Board (CPCB) sets the permissible BOD for rivers at 3 mg/l.
BOD Levels at Key Locations
The DPCC report provided BOD readings from prominent locations in the river:
- Najafgarh Drain: BOD reached a high of 90 mg/l in February 2025, the highest level recorded in two years.
- Shahdara Drain (Kalindi Kunj): The worst readings were seen here, with BOD peaking at 127 mg/l in January 2025.
- ISBT Kashmere Gate: Showing fluctuating BOD values, the readings still exceed the recommended standards significantly.
Factors Behind Worsening Water Quality
Experts believe that the increase in BOD levels is due to several factors, including low environmental flow in the river and inadequate sewage treatment facilities. Bhim Singh Rawat, an activist for Yamuna, pointed out that Delhi’s sewage treatment plants (STPs) have not seen significant upgrades in recent years, which contributes to untreated sewage being dumped into the river.
“The river’s flow has reduced due to a lack of non-seasonal rainfall, which typically helps dilute pollution. Furthermore, the existing STPs and effluent treatment plants (ETPs) are still operating at the same capacity as they were two years ago,” Rawat said.
Delhi Jal Board’s Response
In response to the worsening water quality, the Delhi Jal Board (DJB) is working on developing 12 new STPs in the city, including a 13MGD wastewater treatment plant in southwest Delhi’s Chhawla. This is part of a broader effort to reduce the amount of untreated sewage entering the Yamuna.
Currently, Delhi operates 37 STPs with a combined capacity of 764 million gallons per day (MGD). However, Delhi generates approximately 792 MGD of sewage daily, creating a significant gap in treatment capacity.
HT reported on Tuesday that the Delhi Jal Board (DJB) is working on developing 12 new STPs in the Capital with the aim to reduce untreated sewage being dumped from the Najafgarh drain into the Yamuna river. This included work on a 13MGD (million gallons per day) capacity wastewater treatment plant in southwest Delhi’s Chhawla along with 11 units of smaller decentralised STPs (DSTPs) and pumping stations.
Presently, Delhi has 37 STPs, with a combined capacity of 764MGD. Delhi generates around 792MGD of sewage every day.
Looking Forward
As the water quality in the Yamuna continues to decline, efforts to address pollution are critical. It remains to be seen whether the new STPs and ongoing projects will make a significant difference in improving the river’s condition. Environmentalists and activists are calling for more stringent action and investment in waste treatment infrastructure.
The public and policymakers alike must keep a close watch on the progress of these initiatives, as the Yamuna remains a vital resource for millions in Delhi and surrounding regions.
