Allahabad, India, June 21, 2007—A worker pushes a layer of polluted foam from a drain near where the Ganges River and the Yamuna River meet. According to legend, the Saraswati River also once merged here.

One of India's holiest Hindu cities, Allahabad sits on the increasingly polluted banks of the Ganges.

Polluting industries along the river, as well as large amounts of untreated human waste, have made the river hazardous. Dams built for irrigation have also hindered the river's flow.

The 1,557-mile (2,510-kilometer) river is held sacred by Hindus. The river's water is considered holy even though it's often too contaminated to drink.

The Ganges also provides a home for more than 140 fish species and 90 types of amphibian.

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