Promoting the use of soap nuts to control chemical detergent pollution in lakes is an admirable green initiative. But it is wrong to project that it would totally eliminate the foam at Bellandur lake.
This not only is false, but it also deflects the focus away from the real issues plaguing Bellandur lake. The Government of Karnataka has allocated 50 crores to the tasks outlined in the National Green Tribunal’s Expert Committee Report. The work on those fronts needs to start soon.
The foam issue is very minor compared to heavy metals in the water, which poison both water and food, and cause large-scale kidney failures, cancer and other health issues. In comparison, foam causes inconvenience only for half a kilometer stretch of the channel. But Government of Karnataka has done nothing to address the issue of heavy metals. Industrial areas like Peenya, Kalasipalya, Anepalya and Adugodi continue to produce heavy metals, and there is not a single Effluent Treatment Plant (ETP) that is needed to treat these pollutants. Such untreated sewage also directly comes to Bellandur lake.
Can soap nut offer a medium-term solution to the foam? The devil lies in details. Here are some details to test this claim:
1. No study to estimate the amount and effect of phosphorus on foam
The foam will subside only if the concentration of phosphorus falls below a certain threshold. But there is no study to find what concentration of phosphorus causes the foaming.
Phosphorus (P) comes from not only detergents but also from human excreta. Treating the incoming sewage in STPs has no effect, because the conventional STPs cannot treat phosphorus. Just the human excreta produced in Bellandur catchment overloads the Bellandur lake by a factor of 240! Is that much amount not sufficient to produce foam? There is no study on this.
Secondly, there is no study to find out how much of phosphorus comes from detergents. Then how can we say that the foam is caused by the phosphorus coming from the detergents only, and not human excreta?
Moreover, even if we manage to eliminate the detergents totally, the human excreta factor still remains. Then how can we say that if soap nuts replace the detergents, the foam problem will vanish?
2. Wrong assumption that soap nut can replace detergents in short term
It is assumed that the soap nut would replace the detergents completely. This assumption is not realistic, because of the following factors:
At present, the soap nut extract is not in a position to give a fight to detergents, because,
In summary, a soap nut-based solution is not likely to make a big disruptive impact on lake water quality or the detergent market in near future. Saving lakes needs a different more scientific robust strategy.