The teams to be drawn from different wings of the Ministry of Water Resources would inspect various drains of the river during winters as there is no flow from the glaciers then, which will give ample scope to them to locate the source of discharge released by industries and other polluting factors.
The exercise, which is expected to be completed before the commencement of summer, would be subsequently carried out in all the Ganga-flowing states, sources said.
"For instance, the teams would be inspecting five or six drains (nullahs) at Kanpur to prepare the data. This would help us draw plans on the requirement of treatment plants," an official said.
Moreover, it would also help in quantifying the volume of effluents discharged by the industries for initiating appropriate action in the future.
"Initially, we thought about employing consultancies for the purpose. But we then decided to carry it out on our own as we will have first-hand information about pollution," the official noted.
The exercise is being done in winter since effluents get mixed up in the river's natural flow in summer along with the water from melting glaciers, thus reducing the chances of identifying the source of pollution.
The Ganga originates as Bhagirathi from the Gangotri glacier in the Himalayas at an elevation of about 7,010-m in Uttarkashi district in Uttarakhand and flows for a total length of about 2,525-km before its outfall into the Bay of Bengal through the former main course of Bhagirathi-Hooghly.
Over the years, the Ganga and its tributaries have become the channels of transport for industrial effluents and drains for the wastewater of cities.
The problem has arisen largely due to the discharge of untreated urban waste and industrial effluents from the large and medium cities located along the course of the Ganga and its tributaries.