No "Property Damage" Trigger for Tank Leakage

Walla Walla College hired a tank company in 1991 to install two underground gas storage tanks.  In 2001, approximately 10,000 gallons of gas leaked from one tank into the ground.  The tank installation contractor had two CGL policies in effect from 1990 to 1992. Seeking coverage under those policies to pay for the cleanup costs, the College claimed that the triggering "property damage" occurred at the time of installation in 1991 due to the installer's failure to use proper backfill which in turn set in motion stress to the tank which ultimately lead to the failure and leakage.  The carrier, on the other hand, claimed that there was no covered "property damage" until the leakage in 2001.Division Three held that mere stress to the tank was not enough to constitute "property damage" and therefore denied coverage for the loss under the 1990-1992 policies.  First, the Court noted that the "your product" exclusion" negated any coverage for loss in value to the tank itself.  Next, the Court distinguished continuous trigger cases such as Groul Construction Co., Inc. v. Ins. Co. of North America, 11 Wn.App 632 (1974) by noting that while "a process began" in 1991, the "property damage did not occur until the tank failed in September 2001, long after the policies had expired."