A petroleum spill into the Mississippi River’s being cleaned up after a train hit a boulder being described as about the size of a Volkswagen bug. The Department of Natural Resource’s Joe Sanfilippo says the train was on a track carved out of steep limestone bluffs on the river’s bank about six miles south of Guttenberg.During the winter there are freeze-thaw cycles that loosen the rock and then in rainy times like this past week there are rock slides. The railroad inspects the track daily, but the chunk of rock apparently fell after the inspection was done…and before the train came by. Sanfilippo says it was about ten last (Thursday) night when the engineer spotted the boulder but wasn’t able to stop the locomotive in time. He says “it takes quite a while to stop a train,” but the boulder was up against one rail of the tracks, and gave a glancing blow to the engine and ripped open the fuel tanks as the train passed by. The tanks carry diesel for the train’s locomotive, and Sanfilippo says about two-thousand gallons spilled. Linn County HAZMAT responded to the spill and put booms in the river along the shore to contain the fuel, part of the remediation that’ll be done to clean the site. There was no fishkill or harm to wildlife, and he says the crushed-rock “ballast” that the tracks are built on is porous and absorbed a lot of the fuel, so it’ll slowly seep out with time. The track’s been in place for a hundred years, and Sanfilippo says in his quarter-century on the job they’ve never had anything like this happen.