Article and photos by Michael Sweet
“Welcome to Enbridge Stockbridge Terminal!” rang a greeting to visitors from Enbridge employees Lara Hamsher and Rob Kitchen. After formal introductions and before commencing a tour of the grounds, Hamsher, Enbridge Community Engagement Advisor, led the way down a hallway to a conference room for a quick overview of the facility.
When the presentation began, what jumped out was the fact that the Stockbridge Terminal started as a pump station and a pipe back in 1969. A holding tank was built in 1974, and as demand grew, Enbridge’s facilities in Stockbridge Township expanded as well. The current facility, located along Grimes Road, is home to nine tanks that store 2.8 million barrels of crude oil. Three pump stations at the Stockbridge Terminal handle five or six different kinds of crude—all with just 17 full time employees.
This volume of crude oil stored onsite and flowing through pipes raises obvious concerns about safety and the environment. As Rusty Smith drove visitors around, the Stockbridge Terminal Supervisor and longtime employee of Enbridge explained that each of the tanks has a protective “moat” surrounding it. These moats, he said, can hold up to 110 percent of tank volume and are built to contain spills in the event of a worst-case-scenario discharge.
What about fire? Enbridge claims to have that potential issue covered, too. Each tank has its own floating roof to expand and contract with the gases, plus a foam suppression system. The feed to the system is a considerable distance from the tank, so it could be accessed in the event of a fire. For each tank there is also a spray hydrant to keep it cool in case a neighbor tank were to catch fire. To feed their fire suppression system, Enbridge keeps full a 15-million-gallon retaining pond. To refill their trucks while fighting any fires in the area, local fire departments also have access to the pond to via a roadside hydrant.
An off-site control center monitors all the oil transmission pipes, including the Stockbridge Terminal. As Technical Supervisor Rob Kitchen explained on the tour, all of the pipes at the Stockbridge Terminal have extremely accurate ultra-sonic flow meters, and these meters are constantly monitored for any differences along the fluid travel path. “What goes in at the start,” Kitchen said, “should be what comes out at the end.” If Central Control sees any issues with the flow meters or pressure in the pipes, they can stop the pumps and shut the valves to halt the flow of oil. They can then work with employees in the field, including those at Stockbridge Terminal, to assess the issue and determine where it lies.
When questioned if these tools were in place at the time of the Kalamazoo River spill, which holds the dubious distinction as the nation’s largest land-based spill, Kitchen and Operations Manager Brian Buck, explained that the tools in Stockbridge were not in place in Kalamazoo. “Enbridge is constantly looking at new technologies,” Buck said, “and making upgrades when they make sense.”
To reduce the chance of pipeline failure, Enbridge has increased the number of physical inspection pipe digs that it undertakes when its inspection machines detect anomalies. These machines, called “hogs,” run through the pipes and scan them with magnetic current, checking the pipe’s shape and wall thickness. Newer pipes follow a federally mandated inspection frequency. Older lines, as with the controversial Line 5 that crosses the Straits of Mackinac, may be inspected less often, once a quarter.
Impressive as all of these safeguards, foresight, and planning are, no measures can safeguard against accidents 100 percent of the time. But as long as demand for heat, fuel, and power exists, facilities like Enbridge’s Stockbridge Terminal will be necessary.
If you would like to see the location of the pipelines in Michigan, please visit the National Pipeline Mapping System (https://www.npms.phmsa.dot.gov)