25 years after factory downing shutters, chromium sludge causes groundwater contamination in Chennai's Ranipet

The sludge continues to seep into the groundwater, poisoning it and, thereby, the residents who live around the old SIPCOT complex in Ranipet town. 

Published: 01st March 2020 06:46 AM  |   Last Updated: 01st March 2020 01:15 PM   |  A+A-

The chromium factory building at Ranipet

The chromium factory building at Ranipet | S Dinesh

Express News Service

RANIPET: 25 years after a factory downed shutters, chromium sludge left behind has caused heavy groundwater contamination. While a plan to get rid of the hazardous waste & detoxify water gathers dust, officials fret over how to fund the clean-up.

A lot of water has flowed down the Palar since the Tamil Nadu Chromates and Chemicals Limited (TCCL) factory was abandoned in 1995 but little has been done about the 2.27 lakh tonnes of chromium sludge heaped in its premises.

The reason?

The total cost of safely disposing of the sludge would come up to a whopping Rs 500 crore over the years. While the Tamil Nadu government hopes that the Union government will chip in, the Central Pollution Control Board (CPCB), which flagged the issue in 2015, has said its role is limited to monitoring the remediation.

Meanwhile, the sludge continues to seep into the groundwater, poisoning it and, thereby, the residents who live around the old SIPCOT complex in Ranipet town. 

Asset to liability

When the TCCL was launched in 1975, it was welcomed for providing steady, long-term employment to local labourers and meeting the raw material requirements of the locally-thriving leather industry.

At the time, none seemed aware of the environmental and health dangers the factory posed. 

Over the years, TCCL changed hands before the shutters were finally downed in 1995.

The proprietors had left behind piles of the dangerous sludge and authorities said they were unable to trace them. From being a credible asset, the factory had turned a liability.

Still, the issue evaded attention for 20 years. It was only when the CPCB flagged the problem of the hazardous waste in 2015 that the State government swung into action. 

The chromium factory building at Ranipet | S Dinesh

A silent danger

The Tamil Nadu Pollution Control Board (TNPCB) and CPCB joined hands to prepare a plan for remediation of the dangerous sludge. The CPCB hired a UK-based multinational firm – ERM – which had expertise in hazardous waste management to prepare a detailed project report (DPR) for safe disposal of the sludge and decontamination of the groundwater which has a chromium content of a whopping 20 mg per litre against the permissible level of 0.05 mg per litre.

Local doctors have detailed the effects of the sludge on the health of populace, with one government doctor listing cancer, respiratory problems, skin irritation, kidney failure and liver damage as the consequences. 

“Carcinogenic elements are present in the effluents. They will cause cancer in humans. A lot has been talked of it so far. There shouldn’t be any further delay in initiating the process for safe disposal of the sludge,” said ‘Ambalur’ A Asokan, member Ecology Reversal Committee, Vellore.

Farmers claimed that it is not only health that the sludge has affected, but the fertility of their lands too.

“The effluents have reached the confluence point of the Palar and Ponnai rivers, just 2km away from TCCL, making the water highly contaminated. Even a bunch of grass will not sprout on the land contaminated by the chromium sludge,” ‘Palleri’ K Raja, president of Tamizhaga Vivasayigal Sangam claimed, urging the government to act quickly “to protect the land, water and local people”.

Disposal and decontamination

ERM submitted its DPR 18 months ago. According to the document, the highly dangerous and leachable hexavalent chromium must be converted into trivalent chromium to make it stable.

Then it would have to be encapsulated before being put into a secured landfill of three layers.

The layers of the landfill would be of puddle clay covered with high-density polyethene (HDPE) sheets, topped by clay again and HDPE sheets would be spread around the landfill. A leachate connection would be given to treat leaked sludge during the rains.

The top of the landfill would be covered with two layers of clay and HDPE sheets. The sludge treatment would take two years and post-treatment monitoring would have to continue for a period of 25 years.

The concentration of chromium in groundwater in the direct leach at TCCL is a staggering 50-55 mg per litre and 20 mg per litre a little further away.

Decontamination of the groundwater would pose a bigger challenge. The process would require all the contaminated water to be sucked out and treated to extract the chromium contents and then treated again before being precipitated.

It would take as many as 10 years to bring the level of chromium content in the groundwater down to the permissible 0.05 mg per litre.

Dizzying cost a cause for delay?

According to the DPR, the operational expenditure for sludge treatment would be Rs 223.17 crore while Rs 11.28 crore would have to be spent for water decontamination initially. But that’s not all: Decontamination would also cost an additional Rs 1.55 crore per month for 10 years. As a result, the entire expenditure is expected to run to about Rs 500 crore. The question now is: who will pay?

Passing the buck

“Our role is to prepare the DPR and hand it over to the State government. As of now funds are not available for the project. Tamil Nadu government has to allocate funds. We will monitor the project once remediation starts and have no further role,” a senior CPCB official told TNIE. 

TNPCB chairman AV Venkatachalam said the project was last reviewed by the Chief Secretary in October 2019 and “the process is going on”.

However, a senior official in the State Environment and Forests department admitted that costs were a concern.

“The Chief Secretary has written to the Union Ministry of Environment and Forests seeking funds for the TCCL sludge disposal. We hope at least 60 per cent of the costs will be borne by the Centre given the seriousness of the issue.” 

Meanwhile, environmentalists have also urged the State government to ensure such a situation isn’t allowed to repeat anywhere else in Tamil Nadu.

“The government should learn from the TCCL issue and move forward. Similar hazardous wastes must have been dumped in other SIPCOT industrial complexes as well. That should be investigated,” said G Sundarrajan, an environmentalist.


TCCL proprietors left behind piles of sludge and authorities said they were unable to trace them.

The issue evaded attention for 20 years. It was only when the CPCB flagged the problem of the hazardous waste in 2015 that the State government swung into action


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