Exxon Mopping Up Oil Pipeline Spill in Ark. Critics use accident to slam Keystone XL plan By Polly Davis Doig, Newser Staff Posted Mar 31, 2013 11:50 AM CDT 28 comments Comments This Jan. 27, 2011 file photo shows an Exxon sign in Carnegie, Pa. (AP Photo/Gene J. Puskar, File) (Newser) – Exxon Mobil is mopping up an underground pipeline spill that dumped thousands of gallons of oil on an Arkansas town, reports Reuters, as critics are using the accident to again pounce on the Keystone XL pipeline. A leak detected late Friday in Mayflower forced Exxon to shut its Pegasus pipeline, which was carrying heavy Canadian crude that ended up spilling onto suburban streets. It's not clear exactly how much oil spilled; the Pegasus pipeline is capable of moving 90,000 barrels per day. At least 22 homes in the area were evacuated, but officials say that they prevented the oil from entering a local lake. It's the second mishap involving Canadian crude in a week, notes Reuters; a train derailment Wednesday dumped 15,000 gallons in Minnesota. "Whether it's the proposed Keystone XL pipeline, or ... (the) mess in Arkansas, Americans are realizing that transporting large amounts of this corrosive and polluting fuel is a bad deal for American taxpayers and for our environment," says Ed Markey, a Massachusetts Democrat.