The National Energy Board has ordered Enbridge Inc. to stop work along its Line 3 oil pipeline in Manitoba after an inspection earlier this month revealed numerous environmental and safety concerns.

Line 3 has been carrying crude between Alberta and Wisconsin for nearly half a century. Enbridge announced plans earlier this year to replace the pipeline in its entirety – a $7.5-billion undertaking that would be the largest project in the company's history.

Company spokesman Graham White said Friday the NEB order relates to regular maintenance work on the existing pipeline around Cromer, Man., not the larger replacement project.

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The NEB says it won't allow work to resume until it's satisfied the problems have been fixed by Enbridge.

"During the inspection of the project, it was observed that multiple construction mitigation measures committed to by Enbridge in its Environmental Protection Plan to conserve topsoil, control erosion and manage drainage were not implemented," the NEB said in its order.

That has resulted in "numerous non-compliances observed both on and off the construction right-of-way causing environmental damage to wetlands and property damage to a substantial amount of agricultural land."

The NEB order also said erosion, lack of safe access to agricultural land and open excavations and trenchlines pose safety hazards.

"The resumption of construction activities by Enbridge without a full assessment of damages would cause further detriment to property, safety of the public and the environment," it said.

Before work can continue, the NEB said Enbridge has to complete a detailed assessment of the safety and environmental issues and put together an action plan, with a detailed timetable, to address each item.

White said Enbridge has already started working on the issues flagged by the NEB and that safety concerns will be dealt with immediately.

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He added flooding and heavy rainfall in late June hampered efforts to address the problems, which had been raised by a landowner and about which Enbridge was aware. The issues were related to land around the pipeline, not the pipeline itself, he said.

For the full Line 3 replacement project, White said Enbridge is holding open-houses in communities along the route and plans to submit a regulatory application by the end of this year.

The upgrade will allow the line to pump a maximum of 760,000 barrels per day, up from the 390,000 barrels it is currently able to move.