Groundwater contaminated with leakage from sewer lines in south Delhi's Mehrauli complex

With regular complaints of flooding in Kalo Ram Complex's basement in Mehrauli (south Delhi), a study done by Central Ground Water Boardhas revealed that groundwater could be contaminated with leakage from sewer lines.

Tests in laboratory have found high nitrate content in the groundwater which comes from human faeces, revealed the study.

It's very harmful for the human body, often leading to a condition called 'blue babies' where children are born with holes in their heart. The area which is usually short of groundwater suddenly showed an increase in the level in 2014. Eventually, the water started filling up the basement, causing severe seepage in the building. The complex which is five-storey has 32 shops, including apparel stores and clinics, in the basement and ground floor. There are approximately 15 families living in the building.

Rajesh Sharma, general secretary of the complex, moved Delhi High Court in 2015 after all the agencies concerned with the issue allegedly refused to help.

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"All the agencies told us that the sudden increase in the water level was not their responsibility. We had nowhere to go. For the last two years, we have not been able to operate our shops. The water has to be pumped out every 15 minutes," he said.

Counsel for the complainant told the court that in 2012, Delhi Jal Board had demolished the overhead water tank and started reconstruction of underground water storage tank for supply of water in the locality, causing heavy leakage of water from the supply pipelines to the property in question. However, the counsel for DJB and MCD told the court that they have no problem with the pipelines and even the building was safe to live.

The High Court appointed Dr Rajesh Chandra, scientist, CGWB to carry out an investigation to find out the root cause of the problem.

During investigation, five samples have been collected for analysis, of which two were from groundwater, one from the basement seepage, one from DJB supply water and the fifth one from a pond which contains sewer water also. The result of the analysis showed that the three samples collected from groundwater and basement seepage closely matched with the DJB supply water.

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The report said, "The leakage from sewer lines/soak pits (latrine) or leakage from DJB water supply pipe lines or both may be locally recharging the groundwater in the area, causing its level to rise and thereby affecting the basements."

"Chemical analysis of water samples revealed that sample from Kalo Ram Complex has high nitrate content, indicating possible sewer contamination. However, the concentration of fluoride, calcium and magnesium in water from basement seepage is quite lower than the surrounding groundwater samples," said the report.

The HC has asked the DJB to file a status report in six weeks.

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