India, Jan. 25 -- When 38-year-old Pradeep Kumar Bishwokarma was growing up in Ramgadhawa, a neighbourhood in southern Nepal's industrial town of Birgunj, he would jump into the Sirsiya river to beat the summer heat as his mother washed clothes and residents drew drinking water from it.

Today, Bishwokarma and his fellow residents of the border town cover their noses with a handkerchief whenever they pass by the river that was once their village's lifeline. The flowing liquid no longer resembles a river. It is thick and black as if a truckload of oil had been dumped into it. The air around the river feels heavy with the stench of sulphur and rotting organic matter.

"This is no longer a river," Bishwokarma said, pointing toward it. "It ha...