As World Water Day is being observed on March 22, scientists claim that water in almost 83% of open wells and most of the rivers in Kerala is highly contaminated.
This was revealed by studies conducted by the Centre for Water Resources Development and Management (CWRDM), Kozhikode, which periodically monitors the 44 rivers and examines the groundwater sources in the State.
P.S. Harikumar, Senior Principal Scientist (Water Quality Division), CWRDM, told The Hindu on Wednesday that the rivers were facing three major problems: waste, chemical contamination, and salinity.
“Due to lack of proper management of solid and liquid waste, there is bacteriological contamination in the down stream of rivers such as the Pampa, the Periyar and the Meenachil.
Discharge of effluents from fertilizer and agrochemical industries in the catchment areas of rivers, such as the Periyar and the Valapattanam, was another concern. The third problem is the intrusion of salinity into rivers during summer, sometimes even ahead of it,” he said.
As per a study conducted by the CWRDM recently, most of the rivers in the State do not have enough water in them to dissolve the pollutants.
Rivers naturally have a capacity to assimilate pollutants, which is linked to the flow of water, presence of micro-organisms and the quantity of oxygen in it. Deficit in rainfall is leading to reduced water flow, thus limiting the river’s capacity to assimilate pollutants.
Mr. Harikumar said that pollution in rivers was found to be high near townships and urban settlements.
Reduced water flow
“The reduced water flow and high temperature during summer coupled with dumping of waste have led to phenomena such as blue-green algae in the Chaliyar for the first time in the State,” he pointed out.
Although salinity in river water is considered a cause for concern, the steps being taken to address it is also affecting the water flow. Saline water intrudes into most of the rivers to an extent of 18 km to 24 km by December itself now, much ahead of summer, Mr. Harikumar said.
As this often spreads to places from where drinking water is sourced, the authorities construct regulators to block it. “Regulators often affect the natural flow of rivers,” he pointed out.
As far as groundwater is concerned, unscientific digging of wells on the premises of buildings was a major reason for the bacteriological contamination of water. “Lack of proper sewage treatment is a big problem,” Mr. Harikumar said.