A sample testing undertaken by the MCD from various parts of Delhi has revealed that 18% of the water is unfit for drinking.
Expressing concern over the poor quality of water, which had high quantity of faecal contamination too, the civic body's health department has shot off a letter to the Delhi chief minister to take special measure to fix the problem.
In the letter, the Municipal Corporation of Delhi's (MCD) medical relief and public health committee chairman Dr VK Monga stated that 126 of 747 water samples tested were found to "contain high quantities of bacteria which are usually of faecal origin".
"In the summer season, contaminated water can lead to spread of diseases like jaundice, typhoid and gastro-enteritis, so there is a need to check water pipelines passing along sewers to prevent mixing of sewage and water, clean old pipes and repair them. It is a serious issue and DJB should ensure that Delhiites get clean drinking water," said Monga.
He added that a majority of the samples tested had faecal contamination.
"As per international standard, the bacterial presences in drinking water should be less than five. But in the samples collected by our team, we found more than 10 bacteria," he added.
The survey was ordered after the MCD's public health department received several complaints of cholera and other gastro-related problems in December 2010.
The samples were collected between January and March this year.
"Last year, there was a sharp rise in water-borne diseases in the city. We are making all efforts to ensure that water-borne diseases don't gain epidemic proportions in the city. But if DJB continues to supply dirty water, then we are likely to see a serious outbreak of water borne diseases in the city," said Monga.
The civic agency has asked the chief minister to direct DJB to replace old, corroded pipelines to ensure sewer lines are not flowing over water pipelines.