4. Motion to Dismiss

Equilon and Shell Trading move to dismiss on three grounds. First, they maintain that the doctrines of res judicata and collateral estoppel bar Chevron from maintaining the complaint because it was a party to an earlier adjudication before the California Court of Appeal in which the same 20" Pipeline was deemed not to be a public utility. Second, defendants argue that the complaint is also barred by the doctrine of judicial estoppel, which under certain narrow circumstances prevents a party (in this case Chevron) from taking a position in one case and then taking a contrary position on the same issue in a later case. Finally, Equilon and Shell Trading argue that this Commission since 1917 has declined to exercise jurisdiction over oil pipelines operating through buy/sell agreements and that a Commission investigation of pipelines between 1975 and 1979 was concluded without a change in the Commission's practice.