If you live anywhere along the route of Enbridge’s Line 5 crude oil and natural gas liquids (NGLs) pipeline, which travels 547 miles across the Upper Peninsula, the Straits of Mackinac, and down through Lower Michigan, you should be asking state and local government officials and emergency responders a lot of questions. You should know whether your family’s safety is at risk. Public focus is on the environmental and economic impact of a pipeline failure and crude oil release at the Straits of Mackinac, and now, and an agreement for a possible oil pipeline tunnel in 10 years. This “tunnel vision” does not solve the human safety and property damage impacts along the other 539 miles of pipeline route, not only from a crude oil release, but also from the potential for a huge fireball resulting from an NGLs release.
The integrity of the Line 5 pipeline outside of the Straits is known to be questionable, as evidenced by at least 29 documented spills totaling 1.1 million gallons of oil, numerous repairs, and use of a lower standard of materials and construction for the single 30” pipeline compared to the twin 20” pipelines under the Straits.
Line 5 also transports large quantities of NGLs, a mixture of propane and butane (and perhaps ethane), which is a liquid under the pressure of Line 5’s operation and a gas when released. The NGLs composition in Line 5 as reported by Dynamic Risk Assessment Systems, Inc., the consultant hired by the Michigan Pipeline Safety Advisory Board (MPSAB) is largely propane. Propane is commonly used for home and commercial heating and chemical production, and is purchased everywhere for home barbecues. If Line 5 fails when it is carrying NGLs (which is 20% to 30% of the time), the released NGLs could quickly flash into a gas, ignite, and create a large fire. If ignition is delayed several minutes, a vapor cloud explosion and huge fireball could occur. The public safety and property damage impacts of a Line 5 NGLs release anywhere along its 547-mile length in Michigan are not being questioned vigorously enough. What would be the impact of a NGLs release, fire, and/or vapor cloud explosion?
The Dynamic Risk study included several NGLs underwater release scenarios at the Straits to determine if the resultant fireball would impact the Mackinac Bridge and people in vehicles on the Bridge. Modeling showed that a full-bore 20” pipeline failure at the bottom of the Straits could create a flame envelope of just under one mile, but not touch the Bridge. But what if you are living or traveling near Line 5 upstream or downstream of a new Straits tunnel? Line 5, along its 547-mile length in Michigan:
- Travels through several populated areas along its route: Ironwood, Manistique, Engadine, Naubinway, St. Ignace, Mackinac City, Indian River, West Branch, Linwood, Bay City, Vassar, and Marysville, Michigan.
- Crosses nearly 400 streams, wetlands, or other water bodies in Michigan, runs near many inland lakes, endangering fishing, wildlife, private property, businesses, riparian owners, and the public. Studies conducted for the state designate 74 water-crossing locations as “prioritized,” indicating sensitive areas vulnerable to a spill and including endangered species habitat and sites near drinking-water intake pipes. Some of the waterways include the renowned AuSable, Sturgeon, Manistique, and Rapid rivers, and the Upper Peninsula’s Lake Gogebic.
- Is 65 years old, primarily designed to carry crude oil, but also NGLs, which as a gas or vapor cloud are highly flammable and explosive.
- Is 30” in diameter outside the Straits, thinner, longitudinally welded, and can fail like Enbridge Line 6B did in 2010 in the Kalamazoo River watershed, which resulted in the largest inland heavy crude oil spill in U.S. history.
- Has leaked 29 times upstream and downstream of the Straits, and has been dug up, inspected, and repaired due to detected “anomalies.” In May 2018, Enbridge was fined $ 1.8 million for failing to meet mandated inspection requirements imposed by a consent decree from the Line 6B disaster.
The nearly one-mile flame envelope for an NGLs release at the Straits was determined using a proprietary computer model that is widely used by industry for safety and risk management studies. Could a much larger fireball occur for a pipeline failure outside of the Straits? The answer clearly is: Yes.
An NGL release could be much larger because it would not necessarily be in deep water experiencing hydrostatic pressure resistance. NGL pipeline pressure at other locations could also be higher as a leak at the Straits would be on the low-pressure side of the Mackinac City pumping station. The distance between shutoff valves outside the Straits is also greater, which would result in larger release quantities and fireballs.
Citizens along the entire route of Line 5 should not be lulled into thinking that the risk is only at the Straits and that it will be solved with “tunnel vision.” What is the risk to your family and neighborhood from NGLs and vapor cloud explosion? Do you know where Line 5 is? Do local authorities and emergency responders have disaster scenario information and response plans? This information should be available to you and not out of sight due to “tunnel vision.”
Importantly, there are alternatives to the continued operation of Line 5, which is not vital to Michigan or U.S. interests, as documented in FLOW’s December 2015 report. Line 5 enables the export of Canadian oil, with Michigan being the shortcut and taking all of the risks. Don’t be lulled by “tunnel vision.”
Rick is the former Director of Security, Environment, Transportation Safety and Emergency Services for Rhodia, North America. He is certified in environmental, hazardous materials, and security management, and is a graduate of the University of Michigan and University of Dallas.
 Detroit News Lansing Bureau, “Line 5 tunnel talks set to gain steam”, Published 11:55 p.m. ET, June 4, 2018 | Updated 12:00 a.m. ET June 5, 2018, http://www.detroitnews.com/staff/10046778/jonathan-oosting/
 FLOW (For Love of Water) Public Comments on the Joint Application of Enbridge Energy to Occupy Great Lakes Bottomlands for Anchoring Support Structures and Improvements for Line 5 Pipelines in the Straits of Mackinac and Lake Michigan [HNC- AR90-WAHM0], May 11, 2018, https://staging.flowforwater.org/wp-content/uploads/2018/05/FINAL-FLOW-public-comments-on-Anchor-Permit-05-11-18.pdf