http://JUDIS.NIC.IN SUPREME COURT OF INDIA suggested by Indian and Soviet experts was quiet safe against the strongest earthquake in the region". The petitioners in this case on the basis of expert’s opinion of Professor Jai Krishna and foreign expert James D. Brune submitted that as an extra precautionary measure 3-D Non-Linear Analysis of the dam should be undertaken to evaluate its performance against the maximum possible earthquake. A simulated Dam Break Analysis (DBA) has also been suggested by the four experts as a matter of abundant caution. On behalf of the respondents the counsel separately appearing for different departments and the project authorities have taken uniform stand that 3-D Non-Linear Analysis is neither essential nor feasible for want of necessary competent expertise in India and even abroad. It has also been argued that challenge to safety aspects have been negatived in the earlier decision of this Court rendered in 1992 and the project was allowed to go ahead and by now has progressed to a very large extent. On the safety aspect of the dam particularly when the location of the dam is in a highly earthquake prone zone in the valleys of Himalayas, all additional safeguards are required to be undertaken on the ’precautionary principle’ as contained in ’the RIO Declaration on Environment and Development’ taken in the United Nation conference held in January 1992 to which India is a party. The precautionary principle in RIO declaration reads: "In order to protect the environment, the precautionary approach shall be widely applied by State accordingly to their capabilities. Where there are threats of series of reversible damage lack of full scientific certainty shall not be used as a reason for postponing cost effective measures to prevent environment degradation" [Emphasis supplied] The precautionary principle accepted by India being a party and significatory to international agreement and understandings in the field of environment has become part of domestic law i.e. Environmental (Protection) Act. The Governmental authorities in India cannot be permitted to set up plea of scientific uncertainty of 3-D Non-Linear Analysis of the dam. On the safety aspect the pleas like res judicata based on earlier decision of this Court cannot be allowed to be raised when further developments and events in the course of the project require further precautions to be taken before filling the dam to the optimum capacity. It is not the casse of the respondents that 3-D Non-Linear Analysis of the dam cannot be undertaken with the assistance of foreign experts on the subject. To take care of all eventualities of damage to dam by earthquake, 3-D Non-Linear Analysis of the dam suggested by four experts as a matter of abundant caution must be undertaken. It is only after 3-D Non-Linear Analysis of the dam is completed and the opinion of the experts on the safety aspect is again sought that further impoundment of the dam should be allowed. In M.C. Mehta v. Union of India (Trapezium matter), [1997] 2 SCC 353 this Court has applied ’Polluter pays principle’ and ’Precautionary principle’ of International law as law of the land of this country, India being party to the United Nation Conference and signatory to International Declarations and Agreements. Requirement of the provisions of the Act and the conditional clearance Before taking up the rehabilitation aspect for issuing necessary directions it is required to be stated that in accordance with the provisions of Section 3 of Environment Protection Act, 1986 and Rule 5 of the Environmental Rules 1986, the Tehri Dam Project was granted conditional clearance. A notification dated 27th January, 1994 has been issued under the Act and the rules on Environmental Impact Assessment of Development Project. Under the said notification an Environmental Impact Assessment is Page 33 of 37