New Delhi – The water quality of the Yamuna River remains an enigma, as the Delhi Pollution Control Committee (DPCC) has not uploaded any new data since February. This gap leaves experts and the public in the dark about the river’s current state, undermining efforts to monitor and improve its condition.
The last update, available in February, included critical parameters such as biological oxygen demand (BOD), dissolved oxygen (DO), and faecal coliform. These parameters are essential for assessing the river’s health. Despite a mandate from the National Green Tribunal (NGT) to collect and publish this data monthly, the DPCC has failed to provide updates for the past four months. Inquiries sent to the Delhi government, the DPCC, and the principal secretary (environment & forest) about the absence of data have gone unanswered. Since 2013, the DPCC has been required to publish monthly reports on the Yamuna’s water quality, and since July 2019, for the major drains that empty into it. These reports are crucial for analysing both short- and long-term changes in water quality.
The DPCC’s website does have up-to-date reports on Delhi’s sewage treatment plants (STPs) and common effluent treatment plants (CETPs), with the latest data available until May this year. However, without the river’s water quality data, it’s challenging to understand the overall impact of these treatment facilities. Water samples from the Yamuna are typically collected manually at eight locations, including Palla, Wazirabad, ISBT Kashmere Gate, ITO bridge, Nizamuddin bridge, Okhla barrage, Agra canal, and Asgarpur. Parameters measured include BOD, DO, chemical oxygen demand (COD), pH, and faecal coliform. Similar tests are conducted for over 25 drains in Delhi.
BOD is a crucial measure, indicating the amount of oxygen required by aquatic life to survive. A BOD level of 3mg/l or less is considered healthy. The February report showed BOD levels rising from 1.3 mg/l at Palla to a high of 54 mg/l at Asgarpur, indicating severe pollution as the river flows through Delhi. Faecal coliform levels, another critical indicator, ranged from 2,000 parts per million (PPM) at Palla to 250,000 PPM at Asgarpur in February. The acceptable limit for faecal coliform is 2,200 PPM, highlighting significant contamination from sewage and human waste.
The absence of recent data impedes efforts to assess whether the river’s condition is improving or deteriorating. A member of the South Asia Network on Dams, Rivers and People (SANDRP) emphasised the difficulty in evaluating the river’s health without regular data. In May, the DPCC floated a tender to procure 22 online monitoring stations (OLMS) to provide real-time water quality data along the Yamuna by year-end. This development is expected to enhance monitoring capabilities, though it remains to be seen if it will resolve the current data gap.
Meanwhile, images of dead fish floating in the Yamuna have emerged, signalling low DO levels. Locals reported dead fish appearing along the floodplain a fortnight ago, with the situation improving after recent rains. Fishermen and residents noted that chemical discharges from tanneries in Haryana often turn the river red and lead to fish deaths, exacerbating the pollution problem. A scientist in charge of the Delhi Development Authority’s biodiversity parks programme linked the drop in oxygen levels to high sewage and effluent discharges. The rains have since improved the dissolved oxygen levels, highlighting the river’s dependency on external water inflows to mitigate pollution. Without timely and accurate data, the battle to clean the Yamuna remains hampered, with both immediate and long-term implications for the river’s ecosystem and the communities dependent on it.
