Yamuna's water quality hit new low in 2 years: DPCC report

New Delhi: The Yamuna River's water quality sharply declined in the last two years, with Biological Oxygen Demand (BOD) levels soaring to over 42 times the acceptable standard in January 2025, according to a report by the Delhi Pollution Control Committee (DPCC).

BOD is a crucial indicator of a river's health and its capacity to support aquatic life. It should ideally remain under 3 mg/l.

However, the latest data paints a worrying picture. At the Najafgarh drain outfall, one of the most polluted stretches, BOD levels jumped from 53 mg/l in January 2023 to a staggering 127 mg/l in January 2025 -- the highest recorded in two years.

After showing slight improvement in mid-2023, the levels rose again sharply in early 2024 and late 2024.

The report, titled Progress in Rejuvenation of the River Yamuna, reveals spikes in pollution at key monitoring points, especially between December 2024 and March 2025.

Similarly, at ISBT Kashmere Gate, BOD levels hovered around 40 mg/l over the last two years, spiking to 52 mg/l in November 2023 and 51 mg/l in December 2024.

Downstream of the Shahdara drain near Kalindi Kunj, where the river exits Delhi, the situation is even worse.

BOD readings rose from 56 mg/l in January 2023 to a dangerous 127 mg/l in January 2025, marking the highest levels at that location in three years.

The DPCC report, which tracks progress on Yamuna rejuvenation and monthly water quality as per National Green Tribunal (NGT) directives, highlights the city's ongoing failure to curb pollution in the river despite several action plans.

Experts attribute the worsening water quality to two key factors: a decline in the river's environmental flow due to insufficient rainfall and stagnation in the capacity of sewage and effluent treatment plants.

"There has been little rainfall in Delhi and the upper catchment areas since the last monsoon, which means less dilution of pollutants in the Yamuna.

"Meanwhile, no major upgrades have been made to Delhi's sewage infrastructure," said Bhim Singh Rawat, a Yamuna activist and member of the South Asia Network on Dams, Rivers and People (SANDRP).

Currently, Delhi has 37 sewage treatment plants (STPs) with a combined capacity of 764 million gallons per day (MGD), while the city generates around 792 MGD of sewage daily.

The gap leaves a significant volume of untreated sewage flowing into the river, particularly through drains like Najafgarh.

In response, the Delhi Jal Board (DJB) announced that it is developing 12 new STPs to tackle the issue.

Theses include a major 13 MGD wastewater treatment plant in Chhawla, southwest Delhi, along with 11 smaller decentralised STPs and pumping stations aimed at curbing the discharge of untreated waste into the Yamuna.

Cleaning Yamuna is among the top priorities stated by the BJP government in Delhi which came to power in February this year.