'City lakes contaminated with mercury, lead'

A recent study conducted by the Lake Development Authority (LDA) in 15 prime lakes in Bangalore has revealed shocking details.

The water quality report shows that all lakes are highly polluted with lead and
mercury.

The LDA has submitted the report – a copy of which is with Deccan Herald – to the government for necessary action.

The Lake Development Authority Chief Executive Officer, C K Shivanna, told Deccan Herald that the study was conducted and compiled in March 2014. The results are astonishing.

“We do not have any powers to issue orders or take action. So, we have requested the government and the lake custodians (BBMP and BDA) to take note and take immediate steps on it. We have also requested the Karnataka State Pollution Control Board to take action against the violators as the lakes are highly contaminated with various chemicals such as mercury and lead. Levels of phosphate and nitrates are also very high,” said Shivanna.

The lakes studied were: Puttenahalli, Yellemallappachetty, Giddana (Hoodi), Varthur, Mahadevapura, Bellandur, Agara, Madivala, Mallathahalli, Kammagatta, Thalagattapura, Jarganahalli, Hulimavu and Yediyur.

The water quality was monitored on 11 parameters – water temperature, pH, dissolved oxygen, biochemical oxygen demand, carbon dioxide, nitrate nitrogen, phosphate phosphorus, lead, mercury, E Coli and total plate count.

As per the Pollution Control Board standards, mercury can be tolerated only up to 0.01mg per litre, but the levels in lakes are up to 1.187mg per litre.

Shivanna said that it has been noticed that waste enters into all lakes, which includes sewage and industrial waste. Despite the presence of sewage treatment plants, the lake water is contaminated.

“As a next step, another study is being undertaken of all lakes in Bangalore, especially those in the newly added City Municipal Council and TownMunicipal Council areas. Here, along with a detailed lake study, GPS readings, ground data as per revenue records is being collected, encroachments and photographic evidence of lakes based on ground reality is being studied. This study will be completed in another two months and will also be submitted to the government. Through this study, we want to know how many lakes exist on ground and what their status is,” he said.

Reacting to this, water management consultant S S Ranganathan wanted to know what the government and civic agencies were doing about it.

Industrial and domestic waste is being dumped into stormwater drains and sewage lines which are flowing into the lakes.

Due to this, lake water is polluted and so is the groundwater which citizens consume. Lead and mercury are very difficult to clean once they are mixed in water and the existing treatment plants cannot clean them.