Канада-АҚШ мұнай құбыр желісі және экологиялық апаттары

The Enbridge Pipeline System is an oil pipeline system which transports crude oil and dilbit from Canada to the United States. The system exceeds in length including multiple paths. More than of the system is in the United States while the rest is in Canada and serves the Athabasca oil sands production facilities. Main parts of the system are Canadian Mainline and Lakehead System (U. S. Mainline). On average, it delivers of crude oil and other products to the major oil refineries in the American Midwest and the Canadian province of Ontario. The Canadian portion is owned by Enbridge, while the U. S. portion is partly owned by that company through Enbridge Energy Partners, LP, formerly known as Lakehead Pipe Line Partners and Lakehead Pipe Line Company.

The first portion of the pipeline was built over the course of 150 days in 1950 by a 1,500 man labor force. It crossed approximately from Redwater, Alberta, through Saskatchewan, Manitoba, North Dakota, and Minnesota, to the Great Lakes seaport of Superior, Wisconsin. At the same time, four oil tankers were constructed to carry the crude from Superior to oil refineries in Sarnia, Ontario. Oil first entered the pipe on August 25, 1950, and the first tanker, Imperial Leduc, was launched on November 4. Other tankers that followed were, Imperial Redwater, Imperial Woodbend, and B. A. Peerless. Because the lakes froze in the winter, preventing tanker traffic, the decision was soon made to expand the pipeline all the way to Sarnia. In May 1953, contracts were awarded and construction began. At , it became the world's longest pipeline. A major upgrade was undertaken in the 1990s to replace old pipe and expand the system.

In 1991, Enbridge's Line 3 pipeline spilled 1.7 million gallons of oil in Grand Rapids, Minnesota and the Prairie River, a tributary of the Mississippi River. It was the largest inland spill of oil in U. S. history. Deliberations over construction of a new Line 3 pipeline have drawn resistance from climate justice organizers and Native communities in Minnesota.

On July 4, 2002, 252,000 gallons of crude oil spilled into a marsh near Cohasset, Minnesota due to a rupture of Line 4 running from Edmonton, Alberta, Canada, and Superior, Wisconsin. Emergency responders enacted a controlled burn at 4:45pm the next day to prevent the oil from penetrating into any waterways. The cost of remediating the accident was reported around $5.6 million.

On July 26, 2010, 840,000 gallons of dilbit crude oil leaked from the pipeline in Calhoun County, Michigan, spilling into Talmadge Creek that flows into the Kalamazoo River. Despite alarms at Edmonton headquarters it took eighteen hours and a report from a Michigan utilities employee before the pipeline company acted to halt the flow finally. Enbridge reached a settlement with the U. S. Department of Justice and Environmental Protection Agency for a total of $177 million in response to the spill, along with an additional spill in Romeoville, Illinois later that year. This settlement included $110 million in spill prevention, $62 million in Clean Water Act violations, and $5.4 million in cleanup costs. In addition, the company was fined $3.7 million by the United States Department of Transportation due to 24 violations in pipeline safety regulation. By 2014, the cost of cleanup to the company totaled to $1.21 billion.

In 2018, a tugboat dropped its anchor on the pipeline near the Straits of Mackinac in Michigan, denting the pipe and causing 600 gallons (2,270 liters) of mineral oil to leak from two electric cables.