MACKINAW CITY, MI -- Federal authorities will soon enact a no-anchor zone in the Straits of Mackinac in hopes of preventing further anchor strikes on lake-bottom utility lines.
The restriction zone barring anchoring and loitering by certain boats in the Straits spans about 40 miles wide, from just west of Sturgeon Bay to just east of Bois Blanc Island. North to south, it extends from about St. Ignace to Cheboygan.
The U.S. Coast Guard's navigation restriction goes into effect Oct. 31, a little less than a month before the no-anchor zone established by Gov. Rick Snyder under emergency rule expires.
The zone is about 20 times wider than the one set by Snyder, which begins at the Mackinac Bridge and extends about two miles west.
The U.S. Coast Guard did not return calls for comment on the expansion of the no-anchor zone.
The no-anchor zone is an attempt to prevent further anchor strikes on lake-bottom utility lines, like the one which occurred April 1. In that incident, a tug and barge dragged its anchor across the Straits floor, denting underwater petroleum lines and rupturing transmission cables.
The ruptured cables owned by American Transmission Company spilled an estimated 550 gallons of toxic coolant oil into the Straits. The dented Line 5 oil and gas twin pipelines didn't spill.
"This is one of many critical measures to provide robust short-term protections as we move forward with our long-term plan of putting Line 5 in a utility tunnel and decommissioning the existing pipeline in the Straits of Mackinac," Snyder said in a statement about the Coast Guard's no-anchor zone.
Earlier this month, state officials announced Enbridge Energy will pay for and build a utility tunnel beneath the Straits of Mackinac to house a new Line 5 oil and gas pipeline and other utility connections. Enbridge officials in a statement said the agreement is a "commitment to explore" housing Line 5 in a tunnel.
If all goes to plan, the tunnel will be operational sometime between 2025 and 2028. It's estimated to cost Enbridge between $350 million and $500 million.
At the time of the April 1 anchor strike, there were no restrictions to dropping or dragging anchor in the Straits, only an advisory.
The anchor strike renewed calls to shut down the controversial Line 5. Enbridge Energy, the Canadian company which owns Line 5, floated the idea of piling rocks onto the 65-year-old pipeline to protect it from another anchor blow.
The Coast Guard anchor ban applies only to the following vessels:
- Ships 131 feet or longer while navigating
- Vessels 65 feet or longer engaged in towing
- Ships engaged in trade which are certified to carry 50 or more workers
- Any dredge or floating plant
These vessels can anchor or loiter in the Straits only with advance permission from Coast Guard leadership. Sightseeing, tourism and ferrying vessels can request a waiver.
In an emergency, boats can break the rules "to the extent necessary to avoid endangering the safety of persons, the environment, and/or property," the rule states.
The Coast Guard's proposal does not state what punitive measures a company dragging its anchor in the ban zone would face.
Bills passed by the U.S. House of Representatives earlier this month seek to codify Snyder's no-anchor zone, which begins at the Mackinac Bridge and extends about two miles west. The bills additionally seek to make anchoring in that zone a felony, with a first offense punishable by up to two years in prison and/or of up to $10,000. A second offense would be punishable by up to five years and/or a fine of up to $15,000.
The proposed tunnel to house Line 5 and other utility lines would be drilled through bedrock at depths of about 100 feet beneath the Straits of Mackinac. It would house a new 30-inch Line 5 pipeline and possibly other utility connections.
Snyder wants the Mackinac Bridge Authority, the independent state agency which operates the Mackinac Bridge, to own the tunnel and lease space to Enbridge for the company's new pipeline.
Enbridge and the bridge authority must still agree to numerous details, including those about construction, maintenance and who pays for minor and major malfunctions of the tunnel infrastructure.
The Line 5 pipeline, built in 1953, runs 645 miles from Superior, Wisconsin, to Sarnia, Canada, and transports up to 540,000 barrels of light crude oil and natural gas liquids per day.
A 'worst-case' spill study by Michigan Technological University researchers concluded that Line 5 would gush 2,436,000 gallons of oil, slick 437 miles of Great Lakes shoreline and cost the Canadian company $1.86 billion in damages under a worst-case scenario spill.
The new agreement, state officials touted, puts Enbridge on the hook for more than $1.8 billion in spill cleanup costs.
Under the agreement, Line 5 will be required to shut down whenever waves hit 6.5 feet for more than an hour in the Straits. The previous agreement required a shutdown during 8-foot waves.
High waves add difficulty to any oil spill response.