The Precautionary Principle and the Burden of Proof
Chapter Twenty-Four
Syllabus topic 1, "General Laws on Environmental Concern"
Pages 93 to 96 of 913
In one line
The precautionary principle says that where an activity may seriously damage the environment, the absence of scientific certainty is not a reason for allowing it to continue.
In the wording a student can write in an examination: the precautionary principle in the Indian context means that environmental measures by the State Government and the statutory authorities must anticipate, prevent and attack the causes of environmental degradation; that where there are threats of serious and irreversible damage lack of scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation; and that the onus of proof is on the actor or the developer or the industrialist to show that his action is environmentally benign.
Why an ordinary rule of proof would not do
In an ordinary civil case the person who asserts must prove. Applied to the environment that means a village must prove that a proposed plant will harm it, before the plant exists, on evidence the village does not have, against a proponent who holds all the information.
Worse, environmental damage is often irreversible. If the burden is on the objector and the objector loses because the science is uncertain, and the science later resolves against the project, the aquifer is already saline and the mangrove already gone. A rule of proof designed for money claims produces the wrong answer when the harm cannot be undone.
The precautionary principle reverses the burden for exactly that class of case.
The three parts of the Indian formulation
Anticipate, prevent and attack the causes. This is a duty on the State and the statutory authorities, and it is a duty of anticipation rather than of response. A Board that waits for damage and then acts has not applied the principle.
Lack of scientific certainty is not a reason for postponing measures. The words are taken from Principle 15 of the Rio Declaration 1992, which speaks of threats of serious or irreversible damage and says that lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
The onus is on the developer. This is the operative part and it is the specifically Indian contribution. The developer must show that his action is environmentally benign; the objector need not show that it is harmful.
The decision
Facts. In Vellore Citizens Welfare Forum v. Union of India, AIR 1996 SC 2715, tanneries discharged untreated effluent onto agricultural land and into the Palar river in Tamil Nadu.
Held. The Supreme Court held that the precautionary principle and the polluter pays principle are part of the environmental law of the country, set out the three parts above, and held that the burden of proof lies on the developer to show that his action is environmentally benign. It also held that sustainable development is a balancing concept and that the two principles are essential features of it.
The Precautionary Principle and the Burden of Proof
Why it matters. It is the source of the Indian formulation, and in particular of the reversal of the burden of proof, which no international text states in those terms.
The refinement
Facts. In A.P. Pollution Control Board v. Prof. M.V. Nayudu, AIR 1999 SC 812, the Board had refused consent to a plant for castor oil derivatives proposed within ten kilometres of two reservoirs supplying drinking water to Hyderabad and Secunderabad, and an appellate authority had reversed the refusal.
Held. The Court discussed the precautionary principle at length, holding that it involves the anticipation of environmental harm and the taking of measures to avoid it or to choose the least environmentally harmful activity, that inadequacies of science are the real basis of the principle, that the burden of proof is on the developer to show that there is no reasonable environmental risk, and that in cases of doubt or uncertainty the benefit should go to protection of the environment. It also emphasised the need for expert bodies to assist courts on scientific questions, and it is the decision most often cited for the proposition that environmental adjudication requires technical assistance.
Why it matters. It explains the principle rather than merely stating it, and its observations on the need for expert assistance are part of the reasoning behind the creation of the National Green Tribunal with expert members.
Worked example
A company proposes a bulk drug unit two kilometres upstream of a village's only well. Its impact assessment says the effluent will be treated to the notified standard and that groundwater will not be affected. A hydrogeologist retained by the villagers says the local strata are fractured and that the modelling assumed a uniform aquifer.
Who has to prove what? Under the ordinary rule the villagers would have to prove that contamination will occur. Under the precautionary principle the company must show that its action is environmentally benign, which here means showing that the aquifer will not be affected.
Is uncertainty an answer for the company? No. If the evidence leaves it genuinely uncertain whether the aquifer is fractured, the principle requires the doubt to be resolved in favour of protection.
Is uncertainty an answer for the villagers? It is not a licence either. They must raise a credible threat of serious or irreversible damage. A speculative assertion does not shift the burden; a hydrogeologist's report on the strata does.
What order follows? Not necessarily refusal. The principle points to the least environmentally harmful alternative: a zero liquid discharge condition, relocation of the effluent outfall, piezometers and a monitoring bond. Refusal follows only if no condition will do.
The Precautionary Principle and the Burden of Proof
Distinctions
| Prevention | Precaution | |
|---|---|---|
| When it applies | The harm is known and predictable | The harm is possible but not established |
| What it requires | Measures to stop a known harm | Measures despite scientific uncertainty |
| Burden | On the person alleging, in the ordinary way | On the developer, to show the action is benign |
| Example | An effluent standard for a known pollutant | A moratorium on a new chemical whose effects are unstudied |
Students frequently treat the two as the same. Prevention answers a known risk; precaution answers an unknown one, and the second is the harder and more contested idea.
What it does NOT mean
It does not mean every project must be refused. It requires that uncertainty be resolved in favour of the environment, which usually means conditions, monitoring and the least harmful alternative rather than prohibition.
It does not mean scientific evidence is irrelevant. The opposite: the principle assumes an assessment has been done and addresses what happens where the assessment cannot resolve the question.
It does not mean the objector need say nothing. He must show a credible threat of serious or irreversible damage. Only then does the burden shift.
It does not mean the principle is only for courts. It binds the State Government and the statutory authorities directly, and it is now a statutory obligation of the National Green Tribunal under section 20 of its Act.
Limits and criticism
It can be indeterminate. Almost anything might cause serious harm. A principle that requires proof of a negative can be used to stop any project, and critics say it converts uncertainty into prohibition.
It is applied unevenly. It was explained at length in Nayudu, which then referred the technical questions to an expert appellate authority instead of deciding them, and it was not applied to stop the Sardar Sarovar dam in Narmada, where the Court held that where the effect of a project is known it is the principle of sustainable development, with mitigative steps, that applies.
Reversing the burden may be unfair. Requiring a developer to prove a negative, that no reasonable environmental risk exists, is a heavy burden, and it falls hardest on small proponents who cannot fund studies.
The answer to all three is proportionality: the principle is triggered by threats of serious or irreversible damage, not by every risk, and the response should be the least drastic measure that meets the risk.
Quick revision
- Three parts: anticipate, prevent and attack the causes; lack of scientific certainty is no reason to postpone; the onus is on the developer.
- Source: Principle 15 of the Rio Declaration 1992, given Indian form in Vellore Citizens (1996).
- Nayudu (1999) explains it and says the benefit of doubt goes to environmental protection.
- Prevention deals with a known harm; precaution deals with an uncertain one.
- It is now a statutory duty of the National Green Tribunal under section 20 of the Act of 2010.
- It requires the least harmful alternative, not automatic refusal.
The Precautionary Principle and the Burden of Proof
Test yourself
1. State the three limbs of the precautionary principle as the Supreme Court has formulated them. That environmental measures by the State Government and the statutory authorities must anticipate, prevent and attack the causes of environmental degradation; that where there are threats of serious and irreversible damage, lack of scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation; and that the onus of proof is on the actor or the developer or the industrialist to show that his action is environmentally benign.
2. What is the difference between prevention and precaution? Prevention applies where the harm is known and its occurrence can be predicted, and it requires measures to stop it; the ordinary rules of proof apply. Precaution applies where the harm is possible but has not been established scientifically, and it requires measures to be taken notwithstanding that uncertainty, with the burden on the developer to show that his activity is benign. Prevention is uncontroversial; precaution is the contested idea because it acts in the absence of proof.
3. A villager objects to a project and offers no evidence at all beyond a fear of contamination. Does the burden shift to the developer? No. The principle is engaged by a threat of serious or irreversible damage, and something must be shown to raise that threat credibly, such as a report on the local hydrogeology or evidence about the substances involved. A bare apprehension does not shift the burden, and a rule that it did would make every project unbuildable, which is the strongest criticism made of the principle.
The rest of this subject
These notes are cut from the University's printed syllabus. Open the syllabus itself, or the past papers, for the same subject.