[cogitator]

Ten of the old style cars would hold 200,000 gallons.

Which is a reasonably large amount, but of course the severity of a spill would be more accurately assessed on the basis of what was released, rather than a bulk amount of liquid.

[RightWhale]

There were 2 recent large spills in this region. One was the famous assassination of the pipeline by a resident of the remote bush with a rifle. The other was a tank car derailment when the tracks gave way. Both spills are being or were cleaned up with most of the spillage being recovered. No more than a handful of acres of vole birthing grounds was temporarily lost in either case.