Assam is one state in India which experiences incessant water scarcity despite having a large number of water resources like the river Brahmaputra River along with the tributaries, various ponds, lakes, underground water, heavy rainfall etc.
The Guwahati metropolitan area is no different although the Brahmaputra flows right on its periphery. The Bharalu River was also once an important source of water supply, now having turned into nothing worse than a drain.
Apart from the rivers, Guwahati also has its fair share of other major water bodies which include the Deepor Beel, Dighali Pukhuri, Jorpukhuri, Silsako Beel, Soru Sola Beel, Bor Sola Beel and Soubhagya Pond amongst others. Yet the city continues to complain about insufficient drinking water.
Citizens and experts have often complained about the gradual conversion of most of these water bodies into dumping grounds. To take stock of the pollution level of the Brahmaputra and its tributary, the ‘dying’ Bharalu River, G Plus approached the Pollution Control Board of Assam (PCBA).
The data of the various parameters for Water Quality Index (WQI) provided by the pollution board shows that the quality of water in the major water sources of the city are ‘Unsatisfactory’.
Parameters of Checking WQI under the National Water Monitoring Programme
As per the pollution control board website, the Water Quality Index (WQI) is a single defining criterion, either 'Satisfactory' or 'Unsatisfactory'. There are four main parameters calculated to determine this index which include:
1. Dissolved Oxygen (DO): The measure of how much oxygen is dissolved in the water. It should be more than 4 milligram per litre (>4.0mg/l)
2. Biological Oxygen Demand (BOD): The measure of the amount of oxygen required to remove waste organic matter from water. It should be 3 milligram per litre (