Varanasi ghats: Removing of algal bloom from Ganga is in progress

NMCG team spraying solution in River Ganga in Varanasi to disintegrate algal bloom

If the Ganga water in Varanasi became clean thanks to a considerable drop in pollution levels over the first wave of COVID-19 outbreak and following lockdown, the same stream has now become green owing to algae blooms this time. Local people were taken aback by the change in the hue of the stream, which also drew the attention of environmentalists and scientists from the UP Pollution Control Board's regional office.

And, therefore on Sunday the stretch of the Ganga between the famous Dashashwamedh and Assi ghats in Varanasi had been sprayed with chemicals to clear it of algal bloom, which was emptied from a sewage treatment plant in Mirzapur and spread rapidly due to the presence of nitrogen & phosphorus in river waters, officials said. Reportedly, the bloom was attributed to untapped drains in the Varanasi district.

Reportedly, 3000 litres of bioremediation solution containing 7.5 kg chemical powder were used to clear the algal bloom. Another 3000 gallons sprayed in the damaged areas on Monday, and the effectiveness of the exercise was assessed on Tuesday by spot inspection, according to the cleaning team.

Neeraj Gahlawat, project officer-technical, National Mission for Clean Ganga (NMCG), NMCG Varanasi chairman Rajesh Shukla, and city health officer Dr NP Singh led the team.

According to Shukla, the spray solution helped remove algal deposits from the length within hours by Sunday afternoon.

The algal bloom was initially spotted in Ganga over 25 days ago, according to Varanasi district magistrate Kaushal Raj Sharma, although it vanished temporarily approximately a week ago. After its return on 7th June, a team of specialists was formed to gather water samples, which were examined by the UP pollution control board's laboratory. The algal strains were discovered to be from an STP in Mirzapur.

Referring to two untapped drains that supplied nitrogen and phosphorus for the algae to bloom, UPPCB scientific officer Dr TN Singh explained, “Algae strains flowed into the Ganga from the Chunar oxidation pond and STP in Mirzapur district. This alga flourished in the Varanasi stretch of the Ganga due to the presence of nitrogen and phosphorus (though mild), which primarily come in the river water from untapped drains.”

He added, "One of these drains, having a capacity of 50 MLD, empties into the river in the Asi region, while the other, with a capacity of 10 MLD, empties into the river in the Ramnagar region of the district."