NEW DELHI: The level of dissolved oxygen (DO) — the amount of oxygen available to living aquatic organisms is “nil” at seven of the nine ghats along the banks of the Yamuna in Delhi, according to the latest tests conducted by the Delhi Pollution Control Committee (DPCC).
The biological oxygen demand (BOD), which should be 3 milligrams per litre or less, was as high as 45 mg/l at some places, the readings show. Aquatic life is put under stress if dissolved oxygen levels in water drop below 5 milligram per litre, according to experts.
DO levels were 7.5 mg/l at Palla, where the Yamuna enters Delhi, and 6.3 mg/l at Surghat (downstream of Wazirabad barrage). At rest of the places ‘ including Khajori Paltoon Pool, Kudesia ghat, ITO bridge, Nizamuddin, Agra canal (Okhla), after meeting Shahdara drain and Agra canal (Jaitpur), the DO levels were ni, according to DPCC’s “water quality status of river Yamuna” report.
This means the river was relatively clean at Palla, but the water quality deteriorated significantly by time it reached Khajori Paltoon Pool, which falls downstream of Najafgarh drain.