Bengaluru's water a deadly drink

A majority of Bengalureans, including those living in well-planned areas of Malleshwaram and Hanumanthanagar, are consuming highly contaminated water as pathogens have invaded BWSSB taps and borewells alike, lab reports show. Heavy metals and toxic chemicals have turned groundwater into virtual poison.

DH accessed extensive reports from Ramaiah Advanced Testing Laboratory (RATL), which analysed three water samples -- BWSSB tap, borewell and sumps/tanks -- from over 100 residential areas spread across the city.

Added to this, a separate set of reports on 150 groundwater samples from areas across the city showed the presence of mercury, nickel, magnesium, aluminium and nitrate. This makes the situation grimmer.

Poison in your tap: Sip faecal flow, metal mix

The results of the two mega tests from the NABL-accredited laboratory indicate that the deteriorating quality of the water is the last warning for the rapidly expanding city even as nearly half of its population is struggling for a drop of water.

In almost all the 100 places, one in three water samples was found to contain Escherichia coli or Ecoli bacteria which causes bloody diarrhoea and even kidney failure, high level of other bacteria measured as total bacterial count (TBC) per millilitre along with hardness and turbidity. The samples were collected and analysed over a period of one month.

All the 80 samples from BWSSB taps had one or other contamination with 22 samples containing Ecoli, 43 with a high level of TBC while 74 samples failed the colour test indicating the entry of stormwater or sewage.

Borewells fared the worst in terms of the percentage of failure. Of the 43 samples tested, 30 had Ecoli, 34 had high TBC and 42 failed the colour test while hardness was detected in 25.

Water collected from overhead tanks and underground sumps fared the worst with multiple contaminations, pressing the need for regular cleaning.

Interestingly, even areas like Malleshwaram, perceived as an area where development activities are well planned and regulated, failed to remain an exception. Here, water from BWSSB taps in three of the eight residential areas, as well as two borewells and one tank, had Ecoli presence, high concentration of TBC was found in tanks and borewells from five areas.

BWSSB officials agreed that there were contaminations in the tap water but noted that the number of contaminations was well within the safety limits. “Last year, we tested 33,000 samples of which 381 proved to be contaminated. The failure is at 1.14%, much below the 5% limit. On top of this, we are enhancing methods to monitor and analyse water,” BWSSB Engineer in Chief Kemparamaiah said.

We are looking away from the crisis

The results for Mathikere, Rajajinagar, Yelahanka are as worrying as those in Whitefield and Mahadevapura, who form the 45% of the Bengalureans dependent on borewell and tankers for water.

BWSSB retired chief engineer M N Thippeswamy said the BWSSB has continued to flout the guidelines issued by BIS.

“The BIS guidelines make it clear that testing of samples and the quality monitoring process has to be done by a third party. Officials make all the efforts to avoid that process. Their data fails to get credibility,” he said.

He said the government needs to address several problems at multiple levels before one can expect a fool-proof system for water supply. “At first, the dependency on borewell water needs to stop immediately,” he said.

What is Reverse osmosis (RO) system?

Jubin George Joseph, Chief Operations Officer at RATL, said even water from the reverse osmosis (filters), as well as the 25-litre plastic cans, was not safe. “We have tested samples from RO units and found Ecoli. Technically, they should filter the bacteria besides removing hardness and turbidity. However, if the contamination in the input load is high, the RO membranes do not last long and allow the bacteria to squeeze through,” he said.

Asked about the safety of mineral water supplied in 25-litre water cans, he said major companies which attract government’s attention usually comply with the norms but a comprehensive study is a must before declaring the water from small-time players was safe.

Jubin said microplastics, an emerging concern, was yet another element that requires attention. “These concerns highlight the need for government agencies to update themselves to serve people,” he said.