Nexen pipeline leak in Alberta spills 5 million litres. (5M litres is a bit more than 31K barrels, according to this site).
The only reporting I've found on this is at Canadian sites. It appears to be about 2 1/2 times the size of the Mayflower, Arkansas spill, but didn't impact human homes. Considering that it's apparently from oil sands, an emulsion of bitumen, water and sand, I have to wonder what supporters of the XL pipeline will say.