UPDATE 4-US govt issues corrective order for Exxon spill
* Order says Exxon estimates 3,500-5,000 barrels of oil spilled
* Line was inspected in February, results not yet known
* Arkansas AG launches probe into spill
* Rain could complicate cleanup, nearby lake protected by booms
By Suzi Parker and Kristen Hays
LITTLE ROCK/HOUSTON, April 2 (Reuters) - U.S. pipeline regulators on Tuesday ordered Exxon Mobil Corp to take necessary corrective action for its ruptured pipeline that spilled thousands of barrels of crude oil into a small Arkansas housing development last week.
The U.S. Transportation Department's Pipeline and Hazardous Safety Administration's corrective order said Exxon estimated that 3,500 to 5,000 barrels of crude spewed from the breach. Exxon had so far only said publicly that it had recovered 12,000 barrels of oil and water.
"The cause of the failure is still undetermined and the investigation is ongoing," PHMSA's order said.
Earlier on Tuesday, Arkansas launched an investigation into the cause and impact of the rupture, just as forecast rain was expected to complicate the cleanup. Continued...