For several years there has been need to do research and collect data on the impact of idol immersion on natural water bodies. In the absence of systematic data collection, the campaign to replace toxic chemical substances with natural and biodegradable materials was challenging. The Maharashtra Pollution Control Board published a report of data collection before, during and after the Ganesh festvial in 2023. The data collected was over several water quality parameters and this was taken from nearly 180 locations across Maharashtra. See here to understand the process of checking water quality. 

This extensive data is difficult for the common man to understand and interpret and so the Punaravartan core team decided to decode it into simple language and visual representations. 

The attempt was revealing as the results were not as straightforward as we had assumed they would be. 

Prima facie, it would be expected that certain parameters such as Total Suspended Solids, Turbidity or Total Dissolved Solids would obviously increase due to immersion of man made objects. Levels of acidity and alkalinity revealed by pH are not so obviously evident and the Dissolved Oxyegn which is a key criteria of the health of the water body for habitat of marine life is also complexly impacted. 

As we studied the results of the data a number of grey areas revealed the complexity of measuring the impact of idol immersion. Some of the questions that emerged were:

1. What are the existing pollution levels in the water body – even before the immersion? In areas of high pollution such as in industrial zones, the impact of the immersion is nearly negligible.
2. What is the flow pattern of the water body? Was water released prior to the immersion dates? If it were, then in this case the results would be misleading.
3. The data has been collected across several types of water bodies – the sea, creeks, lakes and ponds, rivers and even wells. How does one compare the results across flowing waters, tidal waters and standing water in the same measure?
4. Temperature of water data was missing – this is a key parameter to calculate overall water quality 
5. Flow data was also missing 
6. How do we compare year wise data to understand whether the situation has improved or worsened? 
7. How do we check the accuracy of the data collected while allowing room for human error ?

In the slides that follow, you can see the visuals and tabular charts as well as rough maps of the locations. In the second slide, you will see some overall inferences made by the team.