A few notes of context on the sky site.
The railroad that caused the fuel seep in the Sky was operating at the standards of the day. There where know real environmental standards in that day and people surely did not understand that an oil plume would travel to the river via the ground water. It also helped create an economic climate that allowed development of the region. Creating all the housing developments and business that pose a much greater risk to the sky and other local rivers than the oil plume ever will.

I grew up fishing that river from birth and I can guarantee you that the plume did less damage than all the people moving into the area and what the Boldt decision has done in the past 30 years. My grandpa drove the trains on that route for over 40 years. Electric's mostly with diesel generators. You would be shocked to see the grease pads they still use on the tracks to lubricate the train wheels.