Yamuna’s pollution worsens, bacteria levels 4,000 times the safe limit: Report

The river, which flows about 22 km through Delhi, enters the Capital at Palla.

A comparison of the report dated July 17 and sampled on July 1 with the previous month’s report reveals that the pollution levels in the river have worsened.

At Palla, the river’s Biochemical Oxygen Demand (BOD) is 8 mg/l, already much higher than the CPCB’s safe limit of 3 mg/l or less. BOD is a significant water quality parameter that indicates the amount of oxygen required to break down organic material in the water.

July data suggests a sharp spike in organic pollution, particularly between Palla and ITO (70 mg/l). Asgarpur, where the river exits Delhi, shows a slight improvement (24 mg/l), though it remains well above safe limits.

This escalating BOD along the Yamuna’s course through the city signals a substantial and worsening discharge of untreated or poorly treated wastewater into the river. Twenty-two drains open directly into the river, out of which a few remain partially tapped, according to official records.

In June, BOD levels at the same sites were significantly lower: 5 mg/l at Palla, 8 mg/l at Wazirabad, 31 mg/l at ISBT, 46 mg/l at ITO, 40 mg/l at Nizamuddin, 30 mg/l at Okhla Barrage, 38 mg/l at Agra Canal, and 44 mg/l at Asgarpur.

Equally concerning are the Dissolved Oxygen (DO) levels, essential for aquatic life, which have witnessed a significant drop over the past month.

It has dipped even at Palla and Wazirabad, where DO levels usually remain above the safe limit.

At Wazirabad, DO levels have plummeted from 6.3 mg/l in June to just 3.4 mg/l in July, below the minimum safe threshold. Further downstream, oxygen levels fall to zero, and only slightly recover to 0.9 mg/l at Asgarpur. The near-total depletion of oxygen renders large stretches of the Yamuna uninhabitable for aquatic organisms.

The most alarming figures, however, are the faecal coliform levels. At ITO Bridge, it was recorded at 92,00,000 MPN/100 ml — over 4,000 times the permissible limit.

Across most locations, the faecal coliform count has worsened since June. Palla recorded 2,700 MPN/100 ml in July (up from 2,100), and Wazirabad 3,900 (up from 2,600).

Downstream, the levels were more than 1,000 times the maximum permissible limit: 28,00,000 at ISBT Bridge, 92,00,000 at ITO Bridge, 11,00,000 at Nizamuddin Bridge, 22,00,000 at Okhla Barrage, 21,00,000 at the Agra Canal near Okhla, and 7,90,000 at Asgarpur.

The July report also reveals a steep year-on-year rise in contamination. For instance, while Asgarpur recorded the worst contamination levels in July 2024, ITO records the highest pollution levels this year.

The DPCC has been submitting these monthly reports, after analysing water samples at eight locations on Delhi’s stretch of the Yamuna, in compliance with National Green Tribunal directives.