For Hindus at Kumbh Mela festival, polluted waters of India's Godavari River cleanse spirits

It's just water, and far from the cleanest you could find. Raw sewage often flows in the Godavari River, bringing with it high bacteria levels. Residue from sand mining can cloud the water. Farm pesticides leech through the soil.

But to the millions of Hindus expected at the Kumbh Mela festival, held this year along the Godavari, touching that water is reverential. It's a way to cleanse themselves of sin, to come close to God, to immerse themselves in a tradition that reaches back into antiquity. They have come to this city from across India and around the world. Entire villages arrive together, and their parties often last through the nights. Thousands of mystics gather.

Water is central to many religions: Christians perform baptisms, Orthodox Jews seek ritual purity in mikvah baths, Muslims wash themselves before prayer. Believers in both Catholicism and voodoo find solace in the waters of Haiti's Saut d'Eau waterfall.

Observant Hindus believe that four drops of holy nectar were spilled long ago during a battle between gods and demons. Since then, the Kumbh Mela has alternated between the four cities where the nectar fell.

This year, the two-month festival is being held in the crowded city of Nasik.

The moment when people immerse themselves is the culmination of all the travel and effort and prayer, and the dark water of the Godavari sparkles from the splash. Some people thrust themselves almost violently in and out of the water. Some go delicately. Some take a gentle swim.

The intensity is so strong you can almost touch it.