1. Ganges River, India
India's largest and most vital freshwater resource, the Ganges, provides water to over 400 million people from its origin high in India's Himalayas to its terminus in a Bangladeshi port in the Bay of Bengal. The Ganga is the second largest river in terms of water flow, producing the world's largest delta, the Ganges Delta, in the Bay of Bengal. Providing fresh water to some 40 percent of the Indian population is just one role the Ganges plays in Indian life. The river's flow irrigates crops and plays host to the largest religious gathering in the world. Once every 12 years, 100 million Hindus take a pilgrimage to Allahabad, India, where the Ganges and Yamuna rivers meet, and immerse themselves in the water hoping to cleanse their sins. Because the Ganges is worshipped for its divine connection to the Hindu gods, many leave offerings to float along the river's surface, including the dead, hoping to speed along the cycle of the after-life.
Yet, despite its indispensable role in sustaining Indian life, the Ganga is the recipient of some of the worst abuse on the planet. Close to a billion gallons of raw sewage gushes into the Ganges each day, much more than the existing sewage treatment facilities can handle, turning the river into little more than a slow-flowing sewer. Though untreated human waste is the single largest contributor of pollution to the Ganges, industrial waste from leather, paper, sugar, and brass factories along the river banks contributes to some 20 percent of the toxic flow of the Ganges. And though the government banned the practice of dumping the dead into the Ganges over a decade ago, thousands still slip under the cloak of darkness to set their loved ones afloat. The bodies are then left to bloat and decompose into the river bed, only exacerbating the pollution problem. Pollution spikes during pilgrimages have also come under recent scrutiny. A study conducted during the latest edition of Kumbh Mela found that Biochemical Oxygen Demand Levels - used to measure organic pollution in water - had risen three points, from 4.4 mg/liter to 7.4mg/liter, after the first day of bathing in the Ganges. According to the BBC, safe levels should not exceed 2 mg/liter.
A host of efforts to clean up the Ganges have been largely unsuccessful, but a $1.5 billion project funded largely by the World Bank hopes to build the necessary infrastructure to make a dent in the pollution epidemic.
wunderground.com