Enbridge Energy Partners LP is a Delaware limited partnership, formed on October 9, 1991. The Company along with its subsidiaries provides crude oil and liquid petroleum gathering, transportation and storage services, and natural gas gathering, treating, processing, marketing and transportation services in the Gulf Coast and Mid-Continent regions of the United States of America. The Company owns and operates the crude oil and liquid petroleum transportation assets of the OLP, which owns the United States portion of a crude oil and liquid petroleum pipeline system extending from western Canada through the upper and lower Great Lakes region of the United States to eastern Canada. The Company operates through two segments including Liquids and Natural Gas. The Company's Liquids segment includes the Lakehead, North Dakota and the Mid-Continent crude oil systems. The Lakehead system consists of a series of interstate common carrier crude oil and liquid petroleum pipelines that are regulated by the FERC, and storage assets, all of which are located in the Great Lakes and Midwest regions of the United States. Its Lakehead system, together with the Enbridge system in Canada owned by Enbridge, forms the longest liquid petroleum pipeline. The Lakehead system, which spans approximately 2,211 miles and includes approximately 5,022 miles of pipe, has been in operation for more than 60 years and is the primary transporter of crude oil and liquid petroleum from western Canada to the United States. The Lakehead system serves the refining centers in the Great Lakes and Midwest regions of the United States and the province of Ontario, Canada. Its North Dakota crude oil system is approximately 683 miles long, has 23 pump stations, multiple delivery points and storage facilities with an aggregate working storage capacity of approximately 1.8 million barrels. The North Dakota system connects directly into the Lakehead system in the state of Minnesota. Its Mid-Continent system consists of approximately 433 miles of crude oil pipelines, including the FERC-regulated Ozark pipeline and approximately 23.6 million barrels of storage capacity, which serve refineries in the United States Mid-Continent region from Cushing, Oklahoma. The Company's Natural Gas segment consists of natural gas and NGL, rail and liquid marketing services, gathering and transportation pipeline systems, natural gas processing and treating facilities and NGL fractionation facilities, predominantly located in active producing basins in east and north Texas, as well as the Texas Panhandle and western Oklahoma. The Natural Gas segment is comprised of five active and five standby natural gas treating plants and 17 active and eight standby natural gas processing plants, excluding plants that are inactive based on current volumes. In addition, Natural Gas segment includes approximately 10,900 miles of natural gas and NGL gathering and transmission pipelines, as well as trucks, trailers and rail cars used for transporting NGLs, crude oil and carbon dioxide. The Natural Gas segment provides natural gas supply, transportation, balancing, storage and sales services for producers and wholesale customers on its natural gas pipelines as well as other interconnected natural gas pipeline systems. The Company's operations including pipeline, gathering, processing and trucking are subject to federal, state and local laws and regulations relating to environmental protection and operational and worker safety.