A corporation which operated two industrial sites found significant amounts of ground water contamination. Its attempt to get insurance cover on the basis that the pollution was sudden and accidental was unsuccessful because the evidence of its expert was rejected as not being based on sound methodology. The pollution exclusion therefore defeated the claim.

On the one site the expert said the contamination around the diesel refuelling area was too large to have been caused by a minor leakage. At the other site he said it was unlikely the fuel spill would have occurred intentionally because of the value of the contaminants lost and other contamination was ‘indicative of a drum overturning and suddenly leaking out rather than from operations’.

When receiving evidence from an expert witness, the court must be satisfied that the witness is qualified as an expert by knowledge, skill, experience, training, or education. The testimony must be based on sufficient facts or data and reliable principles and methods. The expert’s evidence was rejected as not fulfilling these requirements. There was no evidence to show how his experience or expertise led to his conclusions. His conclusions were based on inferences that worked backwards to surmise how the pollution occurred. The expert failed to explain why his inferences were justified. He offered no methodology to explain how he drew his conclusions. The claim failed.

As we have said before, claims rely more on facts than law.

The case is Varlen Corporation v Liberty Mutual Insurance Company.