We tend to think of oil spills on a massive scale, so large they are hard to imagine. Millions of barrels of crude pouring into the Bering Sea from the slashed hull of the Exxon Valdez. Tens of thousands of workers and volunteers combing hundreds of miles of Gulf Coast beaches after the Deep Water Horizon spill.

But in Mayflower, Ark., the scale of an oil spill there is disturbing not for its size, but its proximity. On March 29, a 20-inch buried pipeline burst under the small town, turning backyards into tar pits and suburban streets into oil slicks. ExxonMobil, which operates the Pegasus pipeline, said today that 140 claims have been made since the pipeline burst, spewing thousands of barrels of oil.

No one was injured but more than 20 homes were evacuated from the subdivision, about 25 miles north of Little Rock. Some 640 people have cleaned up about 19,000 barrels already, and according to Exxon "much of the free-standing oil has been recovered."

"Oil is being cleaned up through a combination of pressure washing, use of absorbent pads and removal of contaminated soil and vegetation," the oil company said in a statement. The company hasn't said when the cleanup will be completed or how much it will cost.