Conflicting Groundwater Reports: Madras HC Refuses To Quash 62m Quarry Plan, Orders Anna University And IIT Madras Experts To Investigate

The fifth respondent held a quarry lease at S.F. No. 444/1, Sokkanur Village. Its original mining plan permitted quarrying to a depth of 27 metres; a hydrogeological report submitted for that plan stated that the water table began at 7.3 metres and water-yielding formations lay between 9 and 26 metres.

After the approved quantity had been quarried, the Joint Director approved a modified mining plan permitting quarrying to a depth of 62 metres. A later hydrogeological report submitted for the modified plan stated that aquifers were at 110–115 metres and that no major intersection with the water table was expected up to 100 metres.

The petitioner challenged the modified plan, raising concerns about a water channel and groundwater depletion. Those grounds had also been raised in earlier proceedings before the NGT and the High Court, which dismissed the challenges.

The Court refused the petitioner’s prayer but directed a further expert assessment of groundwater conditions and the potential effects of the increased mining depth.

Rule 41 of the Tamil Nadu Minor Mineral Concession Rules, 1959 makes an approved mining plan a prerequisite to a lease and prescribes requirements for its preparation, approval, review and modification; Rule 42 is also relevant to further orders concerning a mining plan.

In Deepak Kumar v. State of Haryana, (2012) 4 SCC 629, the Supreme Court required due weight to be given to recommendations on the environmental effects of minor-mineral mining, including hydrogeological assessment for mining below the groundwater table.

M.C. Mehta v. Union of India, (2004) 12 SCC 118, was relied on concerning groundwater depletion in the context of quarrying.

The precautionary principle, recognised in Vellore Citizens Welfare Forum v. Union of India, (1996) 5 SCC 647, requires anticipatory protection against serious environmental harm.

The Court also invoked the constitutional duty to protect and preserve the environment, referring to State of Telangana v. Mohd. Abdul Qasim (Died) Per Lrs., (2024) 6 SCC 461.

The Court held that the petitioner could not relitigate the previously considered grounds concerning the water channel and groundwater depletion.

However, the contrasting hydrogeological reports raised a distinct concern relevant to the statutory approval of the modified plan: the earlier report placed water-yielding formations at 9–26 metres, while the later report placed aquifers at 110–115 metres.

Because groundwater interception and depletion must be considered when modifying a mining plan—not only at the environmental-clearance stage—the authority was required to assess whether depletion had occurred during mining, whether mining caused it, and what effect increasing the permitted depth to 62 metres might have.

The impugned approval did not show that this assessment had been undertaken; the Court therefore ordered an expert inquiry while declining to grant the petitioner’s requested relief.

The Joint Director was directed to engage one hydrogeological expert each from Anna University and IIT Madras to inspect the area and report on groundwater conditions, possible mining-attributable interception or depletion, and the potential effects of increasing the mining depth.

If the assessment identified a concern or likely adverse effect, the fifth respondent was to be heard and further orders concerning the mining plan made under Rules 41 and 42.

The exercise was to be completed within four months of receipt of the website-uploaded order; no costs were awarded.