Canada’s Enbridge Inc.’s spill in Wisconsin happened almost two years to the day after a ruptured Enbridge line fouled part of the Kalamazoo River in Michigan, seen above. (Joe Raymond/AP)

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 to 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 Saturday after making “excellent progress” in cleanup, 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-barrel-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 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 Environmental Protection Agency 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 U.S. Web site showed a patch of damp, blackened earth near a stand of trees. Enbridge found some oil on two small farm ponds, but said the ponds 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 a month ago and endured a scathing report from U.S. safety regulators over its handling of the Michigan incident in 2010.

“Enbridge is fast becoming to the Midwest what BP was to the Gulf of Mexico, posing troubling risks to the environment,” Rep. Edward J. Markey (Mass.), 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, a critic of increasing imports of Canada’s heavy oil sands crude.

Canada is the largest source of foreign crude for the United States, supplying more than 2.4 million barrels per day of the more than 8.3 million per day imported by the nation in July. Enbridge’s lines, the world’s largest crude oil pipeline system, carry the lion’s share of those shipments.

Just two months ago, Enbridge kicked off one of its biggest expansions, announcing multibillion-dollar projects aimed at moving western-Canada and North Dakota oil to Eastern refineries and eliminating costly bottlenecks in the 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.

Analysts said the spill may have a limited impact on crude oil futures when trading opens in Asia.

“I think that the pipeline [outage] is more likely to have a greater company impact than it will on the oil [futures] market — I think that global growth and geopolitics will be more important than the pipeline,” said Jason Schenker, president of Prestige Economics in Austin.

U.S. and global oil prices have been balancing the risks of a large-scale disruption in Iranian crude against the struggling world economy this year.

A surge in production from North Dakota and Canada has built up inventories in the Midwest.

Schenker said the impact of the Enbridge disruption on Chicago refineries will depend largely on how much crude they have stockpiled and the length of the outage. Total Midwest crude inventories hit a record high of more than 110 million barrels over the past two months, according to data from the U.S. Energy Information Administration.

In most cases, smaller pipeline leaks can be repaired quickly, although regulators may require significant work if they find any cause for alarm. After the leak in Michigan two years ago — which spilled 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 land owners had been affected and members of one family had been relocated for their safety and comfort, but that most of the spill was restricted to the pipeline right of way.

The company kept its estimate of the spill at around 1,200 barrels — about as much as would fit in six very large oil tanker trucks.

Just weeks ago, the National Transportation Safety Board blasted Enbridge’s handling of the July 2010 rupture of its Line 6B near Marshall, Mich., which led to more than 20,000 barrels of crude leaking into the Kalamazoo River.

The NTSB said that it found a breakdown of company safety measures and that Enbridge employees performed like “Keystone Kops” trying to contain it. The rupture went undetected for 17 hours.

Pipeline regulators fined Enbridge $3.7 million for the spill, their largest penalty ever.

— Reuters