Mark Fischenich: Ask Us: Reader wonders about source, quantity of gas coming into Mankato

Feb. 28—Q: I believe that the gasoline in Mankato comes from the oil refinery in Rosemount. The semi-trucks that deliver the gasoline are pretty large. How many gallons are there in each truck? On an average day, how many truckloads are made to Mankato?

A: There are basically three questions, here: Where does Mankato's gasoline come from? How many gallons do those big tanker trucks carry? How many daily truckloads are required to keep Mankatoans fueled up?

Ask Us Guy looked long and hard for any indication that the government tracks the source of a city's gasoline supply and how much is delivered to each city. He found nothing.

But Ask Us Guy wouldn't be Ask Us Guy if he stopped writing just because he didn't officially have an "answer."

So, here goes:

The reader is right in assuming that Mankato drivers probably depend on the Flint Hills Resources Pine Bend refinery in Rosemount for much of the fuel they buy. But the reader is probably wrong in assuming that most of the fuel is trucked in from Rosemount.

The Pine Bend refinery, lcated about 17 miles southeast of Minneapolis in Dakota County, "supplies about half of Minnesota's motor fuel and about 40% of Wisconsin's, as well as the bulk of jet fuel for the Minneapolis-St. Paul International Airport," according to a 2018 legislative report from the Minnesota House Research Department.

The Pine Bend refinery can process 320,000 barrels of crude per day, according to the federal Energy Information Administration. That makes it the largest refinery in the U.S. among non-oil-producing states. By comparison, Minnesota's other refinery — the Marathon Petroleum refinery in St. Paul Park — has a capacity of 98,000 barrels daily.

The House Research report stated 70% of the fuel and other byproducts produced by the two refineries comes from Canadian crude oil, which arrives via pipelines owned by the Canadian energy company Enbridge. Although Minnesota refineries take a portion of the fuel, the bulk of the oil in the pipelines passes through the state to refineries in states to the southeast. An even larger percentage of the oil coming into Minnesota by train from North Dakota's Bakken oil field is destined for refineries in other states, mostly on the East Coast.

Although most of Minnesota relies heavily on the Twin Cities refineries, some border communities in northwestern, northeastern and southeastern Minnesota receive fuel from refineries in Mandan, North Dakota; Superior, Wisconsin; and Whiting, Indiana.

So, it's reasonable to think the fuel Mankatoans pump into their gas tanks mostly originated in Canada and was most likely refined in Rosemount.

But the fuel's time in a tanker truck probably wasn't very long at all, thanks to the Magellan MidStream Partners massive pipeline system. Magellan's nearly 10,000 miles of pipeline carry vehicle fuel from refineries to terminals in 15 states stretching from North Dakota, Minnesota and Wisconsin to New Mexico, Texas and Arkansas.

The Magellan pipeline system has seven terminals in rural Minnesota, where the refined fuel is blended with ethanol and loaded into tanker trucks for distribution to gas stations. One of the Magellan pipeline terminals is on Highway 68 fewer than two miles from Mankato's western city limits. So local convenience stores have a very convenient local option for wholesale gasoline.

While it doesn't seem to be public information where area gas stations purchase their fuel, a 2011 story in The Free Press indicated that quite a few of them rely on the Magellan terminal.

That 2011 story was about stations in the area receiving incorrectly mixed gasoline — gas that had way more ethanol in it than was intended. The mixing mistake occurred at the Magellan terminal on Highway 68, and Kwik Trip reported that all of its local convenience stores were affected and possibly Kwik Trips as far away as Owatonna. Other stations reportedly affected were SuperAmerica in Mankato and North Mankato, the Lor Ray Deli Mart and the hilltop Quick Mart on Madison Avenue.

(Casey's and Holiday Station Stores, by contrast, said they had none of the bad fuel.)

OK, so the tanker trucks supplying Mankato convenience stores might not have far to travel, but the reader still wants to know how many daily truckloads are required to keep local cars and trucks fueled up.

Ask Us Guy is going to go with ... more than 11.

Q: "More than 11?" Did you just pull that number out of your ear?

A: No, no, no. Ask Us Guy did a bunch of math, made some assumptions, did more math, and then pulled the number from his ear.

Actually, there is some reasoning, to use the word loosely, behind 11. Minnesotans consume an average of 459.92 gallons of vehicle fuel annually, according to the Energy Information Administration. (That's better than Wyoming residents, who burn through more than 600 gallons apiece each year, and worse than New Yorkers, who average just under 300 gallons.)

Since Mankato is a regional center with lots of out-of-town shoppers and commuters driving here for work, it's not just local residents buying fuel here. So Ask Us Guy decided to multiply the 459.92 gallons times 80,000 — which is the estimated workday population of Mankato.

That works out to nearly 36.8 million gallons a year, or 100,804 gallons per day.

Semi-truck fuel tankers can have capacities above 10,000 gallons, but they're generally more in the 9,000 to 9,500-gallon range because of road weight limits, according to several online sources. (Tankers carrying diesel need to carry fewer gallons to abide by weight limits because diesel weighs more per gallon than gasoline.)

Therefore, it would take more than 11 semi-truck fuel tankers each day to provide the needed 100,804 gallons needed.

Q: Mooo! Mooo! I like milk. What is the process that takes milk from the dairy farmer to my cereal bowl?

A: This is an interesting question, but Ask Us Guy's brain is tired and he wonders if readers would mind if he just assumes it works a lot like the whole gasoline thing — just substitute "cows" for "Canadian oil fields" and "dairy plant" for "petroleum refinery"?

Contact Ask Us at The Free Press, P.O Box 3287, Mankato, MN 56002. Call Mark Fischenich at 344-6321 or email your simple, straight-forward, easily-answered questions to mfischenich@mankatofreepress.com; put Ask Us in the subject line.