The Vrishabhavathi river, a tributary of the Arkavathy river, is a stark example of river pollution. What would have been a grand source of pure drinking water to villages all along from Bengaluru to Ramanagaram has turned into a cesspool polluted by industrial, agricultural and domestic waste.
The river isn’t in any state to be tapped as a source of hydro-power too. Veteran envrionmentalist Yellappa Reddy puts the river in perspective: “In the 1960’s I remember the river to be a pure, pristine water flow. By the1990’s, it had turned into a symbol of all that is impure. And having seen the river in both states, I believe there needs to be extra-ordinary commitment and vision to recover its glory.”
The area around the river on Mysore road has several factories which discharge effluents - factories making industrial components, electro-plating works, heavy metals, textile, auto and carbonated drinks, all of which dispose off waste into the river via their drainage systems.
There were not many factories in the sixties, but by the 1980’s many came up along Mysore road, a few kilometres from Bangalore University. From virtually zero discharge, the river saw tonnes of sewage and industrial sully invade it in the 1980’s and 1990s.
Acquatic plants
Reddy explains the transformation of the river. “In the early stages of the river formation, Vrishabhavathi had a wealth of acquatic plants, which would purify waste water. The plants had in-built properties to purify water. All waste that would come from the storm water drain upwards of the river would get destroyed by the acquatic plants, which had the capacity to generate oxygen.”
But as time passed, the quantity of waste coming into the river was so high that the acquatic plants were unable to handle the heavy flow. “It would be accurate to say now that the river has lost its acquatic wealth and its capacity to naturally purify waste water. The absence of acquatic plants is a sign that the river has been invaded totally by waste. What you don’t see anymore is the glory of the white water flowing in great speed.”
You can no longer see fish, crabs and frogs, all of which are part of the river’s total acquatic wealth. The plants would also pump oxygen into the water to resist concentration of waste, but now the oxygen levels have come down, reflecting the rise in population and consequent waste from industries and the heavy discharge into the river.
High mercury levels
Studies by the Lake Development Authority (LDA) have declared that the mercury levels in the water are 500 times higher than the permissible limit, so much so that drinking this water would impact wombs of mothers-to-be. There are also studies by the government to show how this waste water has infiltrated crops all around Ramanagaram and consequently the food supplies.
The milk served and crops around this area show traces of lead, mercury, metal dust, all of which are poisonous. The river now flows with all these pollutants into the Byramanagala lake off Mysore road which was all of 200 acres.There have been reports of yields of paddy and sugarcane going down.
Residents along the river face serious problems –– shortage of clean drinking water and health hazards like asthma, skin and heart diseases. This problem is particularly acute in Byramangala, Chowkalli and Gopalli. The water is not potable, with fecal colifarms making the water unfit for any human use, including for agriculture.
Nitrate concentration
Concentrations of nitrate and total hardness are higher than normal and bacterial contamination in the groundwater too is well beyond the WHO standards. This has been confirmed by M Jiban Singh and others of Department of Environmental Science, Bangalore university, in their study,
‘Bacteriological assessment of groundwater in Arkavathi and Vrishabhavathi basins’. When boiled, says Reddy, the water leaves heavy sedimentation in the vessels comprising sludge. Much of the drinking water is contamined by mud and sewage and there have been cases of people getting out of agriculture and taking up dairying.
The environmental veteran suggests the establishment of an industrial effluents treatment plant somewhere between Jnanabharathi and Bidadi. This will enable the plant to collect the waste at the source itself, rather than at points where the waste is spread-out.
Treating at source is considered the most effective method to handle waste generation. Says Reddy: “My worry is whether anyone would be interested in setting up the plant. If they don’t get any gain from it, they may not get into the project. We require good funding too to build treatment infrastructure, which we lack now.”