After a tongue-lashing, the National Green Tribunal has given Bengaluru's BBMP just 30 days to clean up the highly polluted Bellandur Lake. And while the NGT's order is a welcome relief to the residents, who have been suffering horrendously since 2000, the 30-day time frame feels unrealistic, considering the massive challenges that the BBMP faces. 

Here are three reasons why the lake will not be clean anytime soon: 

1) Millions of litres of untreated sewage 

Some 400 to 500 million litres of water, including treated and untreated sewage, is pumped into the lake every single day. And while there are Sewage Treatment Plants located upstream from Bellandur Lake, they do not function to their full capacity and untreated sewage is routinely pumped into the lake.

To add to that, there is the chaos of differing agencies - like the BBMP, the BDA and the BWSSB, each of whom says it is the other's responsibility to clean the sewage. 

2) Endless housing, endless development 

Even as the old sewage needs to be removed, there is the problem of new waste. Just the Bellandur Lake catchment area, which is considered to be around 150 square kilometres, has some 250 residential complexes.

These homes, part of the massive development boom across Bengaluru, naturally contains thousands of home, each one of whom requires both water supply and expel enormous quantities of sewage each day. 

The city seems to have no set plan to deal with the outflow, other than diverting it further downstream from Bellandur lake. Residents near Varthur Lake are already expressing concern about the increase in sewage in their area. 

3) Many factories, many dumps 

As per the BBMP's survey, there are some 488 industrial establishments along the Bellandur Valley. All of their waste, dumped into canals, eventually feeds into the lake. While many of these establishments are software companies and IT parks, a good number are heavy industries, including highly polluting ones like garment factories.

And keep in mind, the 488 number is just in a five-kilometer radius of the lake. Waste also flows in from across the city. For now, 97 have been given notices, and some 11 are being shut down. Hundreds remain, some of whom will not be able to move for possibly years. 

 

So what will it take to clean the lake? Authorities have to dredge and clean the lake, recharging dead zones, clearing debris and adding fresh water. Then, the hundreds of sewage connections to the lake have to be diverted or sorted. Meanwhile, the BBMP has to build more wastewater treatment plants, shut down hundreds of industries and other polluters. 

And this is just the start. From henceforth the BBMP will have to make sure all the mistakes from 2000 till now are not repeated as well. A large task by any measure.