When it is uncertain on the information available to an evaluator whether or not the impact of a proposed development on the environment will be adverse, the evaluator must accept as a matter of precaution, that the impact will be detrimental. It is a test to determine the acceptability of a proposed development. It enables the evaluator to determine whether enough information is available to ensure that a reliable decision can be made. Generally whenever any application is made for an authorisation such as a license or a permit, an official must be provided with sound, scientifically based, information that should convince the official on reasonable grounds as to what the potential impacts on the environment will be, what the extent thereof is and how it could be mitigated. If such information is not adequate for this purpose, the official cannot be satisfied as is required and should then demand that further information be collected and provided to him.