By Brendan O'Brien
GRAND MARSH, Wisconsin (Reuters) - Canada's Enbridge Inc. on Sunday raced to repair a major pipeline that spilled more than 1,000 barrels of oil in a Wisconsin field, provoking fresh ire from Washington over the latest in a series of leaks.
The spill on Friday -- almost two years to the day after a ruptured Enbridge line fouled part of the Kalamazoo River in Michigan -- has forced the closure of a major conduit for Canadian light crude shipments to U.S. refiners and threatens further damage the reputation of a company that launched a more than $3 billion expansion program just two months ago.
Enbridge said it intended to begin repairs to Line 14 late on Saturday after making "excellent progress" in clean-up, allowing for visual inspection of the line. But it still did not know what had caused the incident and provided no estimate on when the 318,000 barrels-per-day Line 14 would resume service.
An official with the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) said two inspectors were at the site on Sunday, and that all of the pooled oil had been cleaned up.
"The line has been uncovered to begin removing the failed section and send it to a metallurgical lab for examination," PHMSA spokesman Damon Hill said.
Officials from the U.S. Environmental Protection Agency (EPA) and the Wisconsin Department of Natural Resources are also on site, Enbridge said in a statement.
An image of the area posted on Enbridge's website showed a patch of damp, blackened earth near a stand of trees about one-third the size of a football field. It found some oil on two small farm ponds, but said they did not connect to moving waterways and that drinking wells did not seem to be affected.
Although the spill appeared to be relatively small and quickly contained, it comes at a delicate time for Enbridge, which suffered another leak in Alberta, Canada, a month ago and endured a scathing report from U.S. safety regulators over its handling of the Michigan incident in 2010, with employees likened to the "Keystone Kops" for their bungled response.
"Enbridge is fast becoming to the Midwest what BP was to the Gulf of Mexico, posing troubling risks to the environment," U.S. Representative Ed Markey, the top Democrat on the Natural Resources Committee, said in a statement.
"The company must be forthcoming about this entire incident, and deserves a top-to-bottom review of their safety culture, procedures and standards," said Markey, an outspoken critic of increasing imports of Canada's heavy oil sands crude.
Just two months ago, Enbridge kicked off one of the most sweeping expansions in its history, announcing a multibillion-dollar series of projects aimed at moving western Canada and North Dakota oil to Eastern refineries and eliminating costly bottlenecks in the U.S. Midwest.
Line 14 is a 24-inch diameter pipe that was installed in 1998, making it a relatively new line. Enbridge said it had been inspected twice in the past five years.
TWO LANDOWNERS, ONE HOUSE 'COVERED'
In most cases, smaller pipeline leaks can be repaired quickly, although regulators may require significant work if they find any cause for alarm. Following the leak in Michigan two years ago -- which spilled roughly 15 times more oil than the Wisconsin leak if initial estimates of the Friday incident prove correct -- one line was shut for more than two months.
Enbridge said two landowners had been affected and that one family had been relocated for their safety and comfort, but that most of the spill was restricted to the pipeline right-of-way. It kept its estimate of the spill at around 1,200 barrels -- about as much as would fit in six very large oil tanker trucks.
"The house right next to where the pipeline broke got covered with oil," said Patrick Swadish, who lives about a mile northwest of the spill site in a rural area of mostly farmland, some 80 miles north of the college town of Madison.
Oil trucks, Enbridge vehicles and about a dozen crews were working in the area, which had been cordoned off by sheriff deputies. Local law enforcement officials said they had been told it may take up to 30 days to clean the area.
Enbridge also said it had briefly shut down two larger adjacent lines -- the 400,000 bpd Line 61 and the 670,000 bpd Line 6A -- but both were pumping again within a day. Together with Line 14, they form the backbone of Lakehead, a 2.5 million bpd network that is the main route for Canadian exports.
Another line, the 180,000 bpd Line 13, which carries diluents from Chicago to Edmonton, Alberta, would be restarted once it was confirmed the release had not had an impact on it, it said.
Just weeks ago, the U.S. National Transportation Safety Board blasted Enbridge's handling of the July 2010 rupture of its Line 6B near Marshall, Michigan, which led to more than 20,000 barrels of crude leaking into the Kalamazoo River.
The NTSB said it found a complete breakdown of company safety measures, and that Enbridge employees performed like "Keystone Kops" trying to contain it. The rupture went undetected for 17 hours.
U.S. pipeline regulators fined it $3.7 million for the spill, their largest ever penalty.
The incidents, plus the most recent spill in Alberta, have caused furor just as the company seeks approval for its C$6 billion Northern Gateway pipeline to Canada's West Coast amid staunch opposition from environmental groups and native communities that warn against oil spills.
(Additional reporting by Timothy Gardner and Russ Blinch in Washington; Jeff Jones in Calgary; Writing by Jonathan Leff and Matthew Robinson; Editing by Anthony Boadle and Maureen Bavdek)