New Delhi: The Delhi Economic Survey report has expressed serious concern over the water quality of the Yamuna river, saying it is "grossly polluted" due to the flow of untreated sewage and discharge of inadequately-treated industrial effluent.
The annual average water quality of Yamuna, varies throughout its 48-km stretch in Delhi, with rapid deterioration at the downstream of Wazirabad barrage after confluence of Nazafgarh Drain.
The annual average of Dissolved Oxygen (DO) ranged from 0.20mg/l (milligrams per liter) at Shahdara (Downstream) to 8.48 mg/l at Palla. According to prescribed limits, it has to be 4 mg/l at the minimum.
The annual average of Bio-chemical Oxygen Demand (BOD), another criteria to measure water quality, has ranged from 1.99 mg/l at Palla to an alarming 60.33 mg/l at Khajuri Pantoolpul. The permissible limit is as low as 3mg/l for class 'C' river like Yamuna, the report says.
It adds that water quality monitoring results of the drains indicate that most of the drains are not meeting the standards with respect to BOD, Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS).
Explaining the reason behind such abysmal quality of water, the report says, as sewerage system is not provided in unplanned habitats, the waste water generated in unplanned area is discharged into drains.
Non-utilisation of installed capacity (613.72 MGD) of sewage treatment plants is another important issue, it says, adding industrial waste water generated in Delhi is more than 40 MGD.
