California has adopted
the "cause" approach for determining the number of occurrences. State
Farm Fire and Cas. Co. v. Kohl, 131 Cal. App.3d 1031 (1982). See
also Meade Reinsurance v. Granite State Ins. Co., 865 F.2d 992 (9th Cir.
1988). Cf. Bay Cities Paving & Grading, Inc. v. Lawyer's Mut.
Ins. Co., 5 Cal. 4th 854, 855 P.2d 1263 (1993)(distinguishing rule for
"claims made" policies).
Judge Bea ruled in Tosco Corp. v. Hartford Accident & Indemnity Co., San Francisco No. 952681 (Cal. Super. March 1, 1999) that a “cause” approach should be used for pollution claims and declared that policies containing a “deemer” clause which or which provide that damage resulting from “continuous or repeated exposure to substantially the same conditions existing at or emanating from one premises location” will be treated as a single occurrence for each site.
The Court of Appeal has also ruled that a scheme by which various trucking companies allegedly stole $1.5 million in petroleum products in 650 separate incidents constituted only a single "occurrence" for the purpose of determining the available "fidelity" coverage rather than multiple "occurrences" as its property insurer had contended. Eott Energy Corp. v. Store Brand International Ins. Co., 45 Cal.App.4th 565, 52 Cal.Rptr.2d 894 (2d Dist. 1995). But see B.H.D., Inc. v. Nippon Ins. Co. of Europe, Ltd, 54 Cal. Rptr.2d 272 (Cal. App. 1996)(A $10,000 deductible for "each claim for loss or damage (separately occurring)" held to apply separately to each of numerous incidents in which a customer stole jewelry from the insured's store over a period of months).
Where a continuing loss arising out of a single “occurrence” triggers multiple policy limits, a federal district court has ruled that an insured is not entitled to “stack” the separate occurrence limits in the subject policies. Employers Insurance of Wausau v. Granite State Insurance Company, No. CV 92-0406 (C.D. Cal. March 14, 2001)(land subsidence). The court refused to find that th policy limit should be interpreted as “per occurrence per year.”