It is generally not safe to drink water directly from the Ganges River or any other natural water source without treating it first. The Ganges, like many other rivers, can become contaminated with a variety of substances, including bacteria, viruses, and other microorganisms that can cause illness.
In addition, the Ganges has faced significant pollution challenges in recent years due to the high levels of sewage and industrial waste that are discharged into the river. This can further increase the risk of illness from drinking untreated water from the Ganges.