New Delhi: Water quality in the Yamuna showed marginal improvement at some locations in May when compared with April, but the pollution still was alarmingly high across the heavily contaminated stretch flowing through Delhi, according to the latest monitoring report of the Delhi Pollution Control Committee (DPCC).The report, shared on Thursday, is based on water samples collected on May 5. DPCC analyses the samples collected from eight locations of the Yamuna every month.Fecal coliform, an indicator of the presence of sewage in the river, dipped from 1,70,000 MPN/100 ml at ISBT Bridge in April to 1,30,000 MPN/100 ml in May. It was still far above the safe standard of 2500 MPN/ 100ml (most probable number per 100 ml). Other locations, including Wazirabad, ITO Bridge and Nizamuddin Bridge, also saw a marginal reduction in fecal coliform levels.However, Asgarpur, the most polluted stretch of the river, recorded a rise in fecal coliform from 3,10,000 MPN/100 ml in April to 3,30,000 MPN/100 ml in May. Asgarpur, where the Yamuna exits Delhi, recorded the highest fecal coliform levels, indicating the accumulation of sewage and other pollutants along the river’s course through the city.Despite the reduction in bacterial contamination at some locations, dissolved oxygen remained nil at ISBT Bridge, ITO Bridge, Nizamuddin Bridge, Okhla Barrage and Asgarpur, indicating the river’s inability to support aquatic life in these stretches.Similarly, the biological oxygen demand (BOD) level, a sign of the amount of oxygen that organisms need to survive in the water, was met only at Palla from where Yamuna enters Delhi. At 60 mg/l, BOD levels were the highest at Asgarpur, exceeding the safe limit by 20 times. However, it was 50 mg/l in April here. The standard for BOD is 3 mg/l or less for Yamuna.Bhim Singh Rawat, a Yamuna activist and associate coordinator of South Asia Network on Dams, Rivers and People (SANDRP), said DPCC’s latest Yamuna water quality report presents a familiar picture of the river’s continuous degradation. “The Yamuna usually gets some relief only during the flood season, when higher flows dilute pollution. This year, however, forecasts of a weak monsoon due to the emerging El Niño conditions may further worsen the river’s water quality in the coming months,” said Rawat.He added that successive monthly reports make one fact abundantly clear — without adequate environmental flows, the Yamuna cannot be restored. “While govt continues to focus on river cleaning infrastructure through new projects, budgets and action plans, the most critical requirement of ensuring sufficient environmental flows remains largely ignored. Rather than competing to extract more water from the Yamuna, the central and the basin states, including Delhi, now must priorities restoring environmental flows in the river,” Rawat said.
