Frothing Lakes of Bengaluru: An impact of unfit sewer management

Simran Uchil

26th September 2020

The citizens of Bengaluru are no strangers to froth-covered lakes accompanied by a pungent smell - the result of a very obviously mismanaged sewage system. According to the Bangalore Water Supply and Sewerage Board (BWSSB), an average of only one thousand and fifty million litres per day (MLD) of fourteen hundred and fifty MLD of sewage water gets treated every day.

A thick layer of froth caused by the inefficient sewage systems (Source: theguardian.com)

The citizens of Bengaluru are no strangers to froth-covered lakes accompanied by a pungent smell - the result of a very obviously mismanaged sewage system. According to the Bangalore Water Supply and Sewerage Board (BWSSB), an average of only one thousand and fifty million litres per day (MLD) of fourteen hundred and fifty MLD of sewage water gets treated every day.

The Hindu had reported that most of the sewage water is not clean enough to be released back into water bodies. Yet, there are only 24 major sewage treatment plants in the city, none of which work efficiently. Due to the shortage of treatment plants, most of this water goes back into Bengaluru lakes and rivers with improper treatment causing the froth that decorates the water bodies.

Under the guidelines provided by the Central Pollution Control Board, processes of chlorination and dechlorination must be followed, News Minute had reported. These are the most critical processes to get rid of nitrates and produce clean water. However, due to these processes being expensive, these procedures are not followed at all by BWSSB. The absence of these processes is what causes the foaming seen on lakes locally. Most of these sewers require regular maintenance due to pipe bursts and old equipment, which also contributes to its inefficiency. A lot of waste is dumped into open sewers, which contain materials or even industrial waste that STPs are not equipped to treat, which is what causes the equipment to become faulty.

Another problem is that housing apartments are mandated to operate their own internal STPs, and many of these are not maintained correctly, which also contributes to untreated sewage water being released into the source water bodies. ­

However, this is not the worst part. In 2005, more places in the outskirts of Bengaluru were added under the BBMP (Bruhat Bengaluru Mahanagara Palike) for sewage management, which has been completely blindsided. These places have no underground connection to the STPs at all and are removed by labourers mechanically using tankers. Some of the sludge is used as manure by farmers. The rest is dumped in open sewers or empty land.

“Both the BBMP and the BWSSB have washed their hands of removing faecal sludge from unserviced areas. So, these tankers provide an essential service. However, what is being done is human waste movement, rather than management,” says researcher C.S. Sharad Prasad, who studied a number of these workers as part of his doctoral thesis.

14 STPs are under construction in these areas and are expected to be completed by 2025 but will not be in use till 2030. A problem that persists, however, is the ever-increasing population in the city, which is likely to make the increase in STPs redundant.

(Sources: The News Minute, The Hindu, BWSSB) Edited by Satvik Pandey