Accumulated sludge on the Yamuna riverbed and polluted water from drains upstream are contributing to frequent spikes in ammonia levels in the river, which often lead to disruption in Delhi’s water supply, the Central Pollution Control Board (CPCB) has found.
This year, the DJB announced that dredging of the pondage area near Wazirabad barrage will be carried out after monsoon. The pollution watchdog cautioned that dredging the reservoir alone would not resolve the problem. In its submission to the UYRB, Haryana informed the CPCB that multiple steps are being taken to reduce pollution loads in drains ending up in Yamuna, including construction of a Sewage Treatment Plant. The UYRB has suggested that once the pollution load of drains is within acceptable limits, DJB may consider one-time de-sludging of the river bed.
HT reported on August 12 that the UYRB asked the CPCB to study the sludge factor behind the disruption in the water supply due to a spike in ammonia levels. “The CPCB said that due to this, one-time de-sludging of the pond will not be effective, as the sludge carried by water containing high levels of nitrogen will again get deposited in the pond and will restore the problem.
It said the situation would improve only when nitrogen levels in water discharged into the Yamuna through drains are brought within acceptable limits. A government official said the study found that high levels of ammonia in water coming from drains and the accumulated sludge are both the reasons for the rise in ammonia level in raw water. “The programme is being strictly monitored by the Union Home Ministry,” Haryana said in its submission.
