The Institute of Preventive Medicine, which found only 10 water samples contaminated with E.coli in February, has recently identified 30 water samples carrying the dangerous bacteria that causes gastroenteritis. The presence of E.coli in the water sample means it is contaminated with human waste. “The contamination has gone up in the last one month. Steps should be taken to prevent contamination of potable water,” said Mr Anjaneyulu, the chief water analyst, Institute of Preventive Medicine.

Contaminated water samples have been received from Musheerabad, Marredpally, Chilkalguda, Habsiguda, Santoshnagar, Lalapet, Begum Bazaar, Adarshnagar, Kukkatpally, Gandhinagar, Chanchalguda, Golconda, Lalaguda, Hydernagar, Shahalibandu, Misrigunj and Warisguda.

In these localities, there have been instances of drinking water lines and sewage lines leaking into each other, which explains the presence of E.coli.

However, the water board has not taken action even after 14 deaths that occurred due to gastroenteritis in Bholakpur last year. The old and damaged pipelines are yet to be replaced.

“The affected areas have been identified. We are taking steps to repair the damaged pipelines besides ensuring that there is enough chlorination,” a water board official said.