The fears of residents of North Chennai living close to the oil terminals was confirmed on Wednesday when the final report by a team of experts from the Indian Institute of Technology- Madras revealed that the ground water in Tondiarpet area was contaminated. Inflammable chemical compounds such as Benzene and Toluene have been found due to the oil leakage from pipelines run by oil marketing companies (OMCs).
The report also called for an immediate clean-up of the area.
Residents of the region have been complaining about groundwater pollution for more than a year now. Tondiarpet resident K. Umachandran said it has been over a year-and-a-half since their ground water was contaminated. “The contamination is so extensive that even after pumping out oil mixed with water for over 10 months, on March 18, the company collected 54 litres of diesel from three borewells,” he said.
Meanwhile, the Tamil Nadu Pollution Control Board has directed BPCL to commence remediation measures within a fixed time frame. “Since there is toluene and benzene contamination, we have asked them to identify wells that have oil odour and supply water to those residents. They have also been directed to conduct a reconnaissance survey and a gap analysis,” a TNPCB source explained.
Following the oil leakage reported at Tondiarpet in July last year, Bharat Petroleum Corporation Limited (BPCL), whose pipeline was in the vicinity of the reported spill, requested IIT-Madras to carry out a detailed investigation. Faculty member Indumathi Nambi and Ravi Krishna and others conducted the study in the congested area located in Tondiarpet, close to the junction of Thiruvottiyur high road (TH road) and Varadaraja Perumal Koil street.
The final report was submitted before the National Green Tribunal, Southern Bench, which was hearing an application filed by V.P. Krishnamoorthy of Old Washermanpet who sought various reliefs, including shifting of pipelines from the thickly populated area. The report also suggested various remedial measures be taken immediately.
“Groundwater in [the] region was contaminated with many compounds. Benzene and Toluene [levels] in groundwater [is] as high as 23 parts per million (ppm) and 108 ppm respectively,” the IIT report said.
It added that free phase hydrocarbon is present on either side of the pipeline of Varadaraja Perumal Koil street, close to its junction with TH road.
The report also specified the area extent of the oil spread in the aquifer and soil contamination. The experts suggested the installation of monitoring wells in the periphery of the plume to monitor the oil removal and groundwater contamination removal. They suggested the removal of oil-related chemicals and trapped oil from the area through a combination of proven techniques. They also suggested insitu treatment of contaminated groundwater and removal of blobs in saturated zone by chemical or biological methods.
After hearing the suggestions of experts and submissions of the counsel, the Bench comprising its judicial member Justice M. Chockalingam and expert member Prof. R.Nagendran also granted time for OMCs including BPCL to appoint an expert agency in handling remedial measures. The matter was adjourned to May 27.
(With inputs from Deepa H. Ramakrishnan)
