US Ecology, Inc. v. State

On this appeal we are presented with an issue of first impression: whether a plaintiff pursuing a claim for promissory estoppel must prove that the defendant on that claim caused the plaintiff’s damages. We conclude that, as in ordinary contract actions, a plaintiff seeking recovery on a promissory estoppel theory must prove that the defendant’s breach was a substantial factor in causing the plaintiff’s damages. Further, even if we were to conclude that causation is not a necessary element of all promissory estoppel claims, we hold that because promissory estoppel is an equitable remedy, courts have the discretion in an appropriate case to deny relief where the plaintiff cannot demonstrate that the defendant’s actions caused the plaintiff’s damages. Finally, we conclude that substantial evidence supports the court’s decision in this case that defendants’ actions were not a substantial factor in causing plaintiff’s damages.

In 1985 the State Department of Health Services (the Department) selected plaintiff US Ecology, Inc. (Ecology) to develop and operate California’s first low-level radioactive waste (LLRW) storage facility. Ecology and state officials thereafter…