The Supreme Court on Monday refused to hear a petition raising concerns about possible mercury leakage from the residual ash left after the incineration of toxic waste at the Union Carbide site following the 1984 Bhopal gas tragedy.

The Top Court directed petitioner to approach the High Court for relief.

A bench of Chief Justice of India Surya Kant and Justice Joymalya Bagchi allowed the petitioner, Bhopal Gas Peedith Sangharsh Sahyog Samiti—an organisation representing victims of the 1984 tragedy—to move the Madhya Pradesh High Court with material showing the possibility of mercury leakage.

The petitioner relied on a report by Dr. Asif Qureshi of IIT Hyderabad, which stated that a large amount of mercury was present in the incinerated material, raising concerns about possible contamination of groundwater and the surrounding environment at the disposal site.

While disposing of the petition, the bench observed:

"The appropriate recourse would be to move an application before the High Court, along with supporting material showing apprehension of leakage in the future.''

The petition challenged the order passed by the Madhya Pradesh High Court on December 10, 2025, which allowed the disposal of the waste at Pithampur.

Earlier, in October 2025, the High Court had rejected the Madhya Pradesh government’s proposal to store toxic residual ash at the Common Hazardous Waste Treatment, Storage and Disposal Facility (TSDF) in Pithampur, Dhar district, noting that the site was located barely 500 mtrs from residential areas.

However, in December 2025, the court kept its earlier direction in abeyance and permitted the disposal of the residue at Pithampur.

Senior Advocate Anand Grover, assisted by Advocate-on-Record Anuj Kapoor, submitted that after the High Court’s order the waste was incinerated and raised concerns about possible mercury leakage from the residue.

Grover said that around 15 kilograms of mercury had been found in the residual soil in 2015. However, after the waste was incinerated following the High Court’s order, a report claimed that no mercury was present in the residue. Questioning this finding, Grover cited a recent study by Dr Asif Qureshi of IIT Hyderabad, which flagged that mercury was not properly measured in the trial run report.

The bench, however, noted that the oversight committee supervising the process had not yet responded to Dr Qureshi’s report.

Grover argued that mercury was present in the incinerated residue and could leach into the soil. The bench, however, said that the issue could be examined by the High Court.

Justice Joymalya Bagchi observed that while the petitioner’s expert had questioned the methodology adopted by the oversight committee for detecting mercury, the committee had concluded that mercury levels were within permissible limits. He said the matter required examination by experts and that the oversight committee should respond to the report before the High Court.

Grover urged the Court to order the opening and examination of the concrete boxes containing the incinerated ash to check for mercury, but the bench refused, noting that the High Court was already monitoring the matter.

“If, for argument’s sake, mercury is found, what do you propose then? You are trying to get indirectly what you cannot get directly,” Justice Bagchi remarked, adding that the expert committee should examine the issue and suggest steps if leakage is found.

Grover agreed to approach the High Court again but requested that the matter be placed before a different bench.

The petition raised concerns about the safety of the Pithampur disposal site, pointing out that the Madhya Pradesh Pollution Control Board had issued a show-cause notice in December 2024 alleging toxic seepage from the facility contaminating groundwater as close as 50 metres away.

It also relied on observations by Dr Asif Qureshi questioning the reliability of the 2025 trial run report on incineration of Union Carbide waste. While a 2015 report by the Central Pollution Control Board had detected significant mercury levels in the waste, the 2025 trial report claimed that mercury was “not detected”.

The petition argued that the report failed to conduct a proper mass balance analysis and that substances like activated carbon and sulphur used during incineration could have trapped mercury in the residual ash. It also contended that the testing method used may not have been suitable for detecting mercury, leading to potentially inaccurate conclusions about the safety of the disposal process.

Case: Bhopal Gas Peedith Sangharsh Sahyog Samiti vs Union of India | D No. 8813/2026