The Precautionary Principle

Facts. The Andhra Pradesh Pollution Control Board refused consent to a company proposing a castor oil derivatives plant within the catchment area of two lakes that supply drinking water to Hyderabad and Secunderabad. An appellate authority allowed the company's appeal against the Board, and the matter came to the Supreme Court.

Held. The Court examined the inherent uncertainty of scientific proof in environmental matters and the way legal thinking had changed between Stockholm in 1972 and Rio in 1992. It worked through the precautionary principle and the new concept of the burden of proof recognised in Vellore Citizens, and emphasised the need for adjudicating bodies with scientific expertise to decide questions of this kind rather than courts sitting alone.

Why it matters here. It supplies the reasoning Vellore assumes. If the burden lay on the objector, then in every case where the science was unsettled, and the science is almost always unsettled, the activity would go ahead. The shift is not a thumb on the scale; it is what prevents uncertainty from operating as a licence. The case is also part of the line of reasoning that led to specialised environmental adjudication and eventually to the National Green Tribunal.

What the shifted burden requires in practice

It is not proof of a negative. A developer cannot prove that nothing bad will ever happen and is not asked to. What he must show is that he has identified the risks, assessed them properly, and provided for them: the study was done, the alternatives were considered, the safeguards are adequate and enforceable.

It is discharged by process as much as by result. This is why the environmental impact assessment machinery matters so much, and why Alembic Pharmaceuticals holds that a clearance cannot be granted after the event. The screening, scoping, public hearing and appraisal ARE the discharge of the burden, and a clearance granted without them is a clearance granted on no evidence.

It does not settle every case against the developer. In Alembic Pharmaceuticals itself the Court applied the precautionary principle and nevertheless declined to revoke the clearances or close the industries, directing compensation instead.

A worked example

A company proposes a plant that will discharge treated effluent into a creek. The effluent contains a compound whose long term effect on marine life is disputed: two studies find no effect at the proposed concentration, one finds a reduction in fish larvae survival, and none has run for more than two years. The creek supports a fishery.

Under the ordinary rule. The objectors assert harm and must prove it. They have one study out of three, over a short period. They fail, and the plant is built.

Under the precautionary principle. First, is the threatened damage serious and irreversible? Loss of a fishery on which a community depends is serious, and if the species does not recover it is irreversible, so limb (ii) is engaged. Second, the uncertainty cannot be used to postpone measures, so the Board is not entitled to say it will decide when the science is clearer. Third, the onus is on the company: it must show that discharge at the proposed concentration is environmentally benign.

What the company can actually do. Commission the longer study. Propose a lower concentration with a margin. Offer monitoring with an automatic reduction if larvae counts fall. Show that a zero discharge option was considered and why it was rejected. Any of those may discharge the burden. What will not discharge it is pointing out that the objectors cannot prove harm.

Distinctions

What it does NOT mean

It does not mean that any risk defeats a project. The threshold in limb (ii) is a threat of serious and irreversible damage. A speculative risk of minor and reversible harm does not engage the principle.

It does not mean the developer must prove a negative to a scientific standard. The burden is to show the action is environmentally benign on the material available, through a proper assessment, not to establish impossibility.

It does not mean a regulator may refuse without reasons. The principle empowers a regulator to act under uncertainty. It does not relieve it of the duty to say what the risk is, why it is serious, and why the safeguards offered are inadequate.

Limits and criticism

Applied without a threshold it would forbid everything, because no activity is certainly safe. The words "serious and irreversible" are what keep it workable, and a judgment that ignores them is applying something else.

It can be used to avoid deciding. A tribunal that invokes precaution instead of examining the evidence has used the principle as a substitute for reasoning rather than as a rule about who bears uncertainty.

Quick revision

• Three limbs from Vellore Citizens, AIR 1996 SC 2715: (i) anticipate, prevent and attack; (ii) where damage would be serious and irreversible, lack of scientific certainty is no reason to postpone measures; (iii) the onus of proof is on the actor or developer to show the action is environmentally benign.
• A.P. Pollution Control Board v. Prof. M.V. Nayudu, AIR 1999 SC 812, supplies the reasoning: the uncertainty of science means that a burden on the objector lets the activity proceed by default.
• The burden is discharged through assessment, which is why prior environmental clearance matters and why an ex post facto clearance is impermissible.
• Section 20 of the NGT Act 2010 makes the Tribunal apply it.

Test yourself

1. State the three limbs of the precautionary principle as the Supreme Court stated them for Indian law. Environmental measures by the State Government and the statutory authorities must anticipate, prevent and attack the causes of environmental degradation. Where there are threats of serious and irreversible damage, lack of scientific certainty shall not be used as a reason for postponing measures to prevent environmental degradation. And the onus of proof is on the actor or the developer to show that his action is environmentally benign.

2. Why is the shift in the burden of proof the important limb? Because scientific proof of environmental harm is slow, expensive and rarely conclusive, so whoever bears the burden loses in the ordinary case. If the objector bears it, uncertain activities proceed by default and the damage is done before the science settles. Shifting it to the developer means uncertainty stops the activity rather than permitting it, which is the whole practical content of the principle.

3. Does the principle apply to every environmental risk? No. Limb (ii) is confined to threats of serious and irreversible damage. That threshold is what distinguishes the principle from a general prohibition on risk, and a decision that applies it to a minor or reversible risk has misapplied it.

4. How does a developer discharge the burden? By proper assessment rather than by proving a negative: identifying the risks, having them studied by competent persons, considering alternatives, and offering safeguards adequate to the identified risk and capable of being enforced. This is why the impact assessment process is the practical form the principle takes, and why a clearance granted after the activity has begun cannot discharge it.