Yamuna pollution up at 3 sites, BOD above limit

The Yamuna River, which enters Delhi at Palla Village and exits at Jaitpur, saw a slight deterioration in water quality at certain locations in September, with faecal coliform levels dropping sharply from the previous month, according to the Delhi Pollution Control Committee (DPCC).

The Biological Oxygen Demand (BOD) levels, meanwhile, remained high and well beyond the permissible limit for September. DPCC water quality testing involves collecting water samples from seven locations along the Yamuna River through the national capital and measuring parameters such as BOD, dissolved oxygen, chemical oxygen demand, pH, and faecal coliform to determine pollution levels.

The seven locations include major points like Palla, Wazirabad, ISBT Bridge, ITO Bridge, Nizamudin Bridge, Okhla Barrage and Yamuna River at Asgarpur (Kidwali, Haryana). Three locations showed further deterioration, two showed slight improvement, and two showed no change from the August data.

The September report showed improvement at Palla, as faecal coliform levels fell to 1100 Most Probable Number per 100 millilitres (MPN/100 ml), down from 1400 MPN/100 ml in August. MPN provides a statistical estimate of viable microorganism concentration in a sample. The river also improved at Okhla Barrage, where faecal coliform levels remained at 21,000 (MPN/100 ml) in September, down from 23,000 in August.

The three locations which showed deterioration were Wazirabad, where faecal coliform levels increased to 1,300 MPN/100 ml in September from 1,100 MPN/100 ml in August; Nizamudin Bridge where the level went from 13,000 MPN/100 ml to 15,000 MPN/100 ml; and Yamuna River at Asgarpur where the level increased from 36,000 MPN/100 ml in August to 38,000 MPN/100 ml in September.

Two locations showed no change: ISBT Bridge (35,000 MPN/100 ml) and ITO Bridge (17,000 MPN/100 ml).

BOD levels for September remained beyond the permissible limit at certain locations, ranging from 2-30 milligrams per litre (mg/l), while the water quality criteria stipulates a maximum of 3 mg/l.

The highest BOD was recorded at ISBT Bridge at 30 mg/l. The highest BOD in August was also recorded at ISBT Bridge, at 28 mg/l.

The DPCC also uploaded wastewater quality data for Delhi’s major drains for September, which show that several drains discharging directly into the Yamuna, as well as supplementary drains of the Najafgarh canal, had high BOD and TSS (Total Suspended Solids) levels.