Bleak outlook on river water quality
New Delhi: Nearly three decades after it first set criteria for river and water body quality, the government finds the situation today is much worse than it was way back in 1978. Reviewing these standards for the first time since then, the Central Pollution Control Board says the No. 1 culprit even today remains coliform bacteria—a red flag for water-borne diseases, since it could signal the presence of human or animal waste.
River stretches near cities are the worst in the country—Yamuna in Delhi, Sabarmati in Ahmedabad, Gomti in Lucknow, Musi in Hyderabad, Adyar in Chennai and Mithi in Mumbai.
The Yamuna’s Delhi stretch, with no naturally flowing water most of the year, has the heaviest pollution load in the country. CPCB is reviewing and rationalising its entire strategy of classifying river stretches and will add pesticide and heavy metal parameters to its existing criteria. The question is, will anybody work to meet these criteria?
This hasn’t happened in 27 years. Officials monitor stretches and identify the worst, this doesn’t mean those stretches improve. “We need to rethink the whole strategy,” says Sunita Narain, head of NGO Centre for Science and Environment.
The biggest problem, says CPCB additional director R C Trivedi, is sewage treatment nowhere matches the quantities of waste generated. Over 18 crore people living in 900 towns, each with populations of more than 50,000, throw out 26,000 million litres a day (MLD) of waste.
Just about 7,000 MLD is treated — most of this capacity has been created through river action plans. Delhi generates 3,600 MLD but actually treats just over 1,400 MLD.
Delhi’s Yamuna has the highest coliform count, even going up to 10 crore per 100 ml. For the class in which this stretch falls, the MPN (most probable number) of total coliform organisms per 100 ml should not be more than 5,000. “Coliform should be zero for drinking water, it never is,” says an official.
What has changed in 27 years? Most rivers are drained of water so the gap between what sewage or effluent clean-up technology could achieve and what rivers could then “assimilate” (or dilute) is growing. “In the state we are in, where rivers have no assimilative capacity, we need standards based on the receiving media,” says Narain.