May assessment report shows Yamuna water failed to meet basic quality standards: DPCC

New Delhi, May 22 (PTI) The latest monthly assessment of the Yamuna river at most places in the national capital fails to meet basic water quality standards, the Delhi Pollution Control Committee (DPCC) said in a report.

On May 1, water samples were collected from eight monitoring points including -- Palla, Wazirabad, ITO, Nizamuddin, Okhla, and Asgarpur -- which showed high concentrations of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and fecal coliform, it said.

According to the report, the higher concentration of BOD, COD and fecal coliform indicate severe organic and bacterial contamination.

The committee said BOD which reflects the amount of oxygen needed by bacteria to break down organic matter in water, were recorded at extremely high levels ranging from 4.0 milligrams per litre at Palla to 64.0 milligrams per litre downstream at Okhla.

The permissible BOD level for Class ‘C’ water (designated for outdoor bathing) is only 3 milligrams per litre.

It said that COD levels, which indicate the presence of oxidisable pollutants, peaked at 171 milligrams per litre at ITO Bridge -- above the acceptable limit of 250 milligrams per litre for inland surface waters.

Fecal coliform levels, an indicator of sewage contamination, at the ITO Bridge reached 92,000 most probable number of microorganisms per 100 millilitres of a sample -- nearly 37 times the maximum permissible limit of 2,500 MPN/100ml.

Elevated coliform levels were also logged at all other downstream points, pointing to widespread sewage discharge and untreated waste entering the river, the report added.

Ammonical nitrogen, a marker of domestic and industrial waste-water, was also found to be in excess, with levels rising up to 5.75 milligrams per litre at Nizamuddin Bridge. The safe threshold for this parameter is typically below 1 milligrams per litre.

The only relatively cleaner site was Palla, located upstream in north Delhi, where the Yamuna enters the city, it said. PTI NSM NSM OZ OZ