Claiming that replacing old and damaged pipelines - as one of the means to prevent contamination - is a continuous exercise, the DJB has claimed it has replaced 642km of the 14,000-odd km network since April 2008.
It has, however, claimed that the work faces hurdles either due to "delay in permission by MCD for cutting of roads" or due to "haphazard network, at times, chaotic" in unplanned, unauthorised colonies.
In an inspection-cum-survey, the MCD had found out that 315 out of 4,816 samples collected in the current year were contaminated. The agency also claimed that it had informed the DJB that of the 642 pipelines that run cutting the nullahs, of which only seven have been repaired.
The DJB says it replaces, on an average, 200 km of pipelines per year. While 241km pipeline was replaced in 2008-2009, 192kms and 184km were replaced in 2009-2010 and 2010-11 respectively. "Since April 2011, we have already replaced 25 kms," said a DJB official.
Sanjam Chima, consultant (PR) for the DJB, said, "The MCD takes in advance the charges for road restoration from us. But at times, there is a huge delay in giving us permission for cutting of the road."
Another problem is that a major portion of the network lies in areas which were developed in an unplanned manner. In many cases, there is also a mixed system of drainage and sewerage wherein the water pipelines pass along side the drain. "Apart from the absence of dedicated utility corridors, the houses are so cheek-by-jowl, where do we dig?" she asked.
The DJB also blamed consumers for not maintaining their end of the pipeline. "It has been found out that the line connecting the house with DJB's line is not changed for years, which is the responsibility of the house owner," an official said. "We had floated a scheme wherein people could pay up and we replaced these connecting pipelines. But there were not many takers," he added.
Stating that some contamination was found in about 0.6 % cases from the water samples lifted in the last three months by DJB's surveillance team, the officials said, "It was well below the WHO guidelines and were generally in unplanned localities."
DJB starts SMS service
The Delhi Jal Board has started an SMS service for taking care of water contamination. In the event where any consumer suspects there is contamination in the water supplied to his house, he/she can send an SMS to 53030 by typing "DJB <space> C".
The officials from the board will call you back to get details and work out the solution, if there is a problem.