A leaky pipeline was the source of a spill, seen in this 2015 file photo, that polluted Refugio State Beach, north of Goleta, Calif., and killed hundreds of birds and marine mammals.

A leaky pipeline was the source of a spill, seen in this 2015 file photo, that polluted Refugio State Beach, north of Goleta, Calif., and killed hundreds of birds and marine mammals.