By Anna Waugh

Though we’ve come a long way in the past few years towards achieving a more sustainable campus, Macalester is still one of the most polluting colleges in the area. The reason: #6 fuel oil, a heavy residual fuel oil with the consistency of tar that is produced from what is left over after gasoline and other lighter distilled fuels have been extracted. Though it is often the least expensive choice of fuel and produces more BTUs by weight than other fuels, meaning less fuel needs to be burned overall, #6 fuel oil emits more air pollutants, such as sulfur oxides, nitrogen oxides, and methane into the air than the other choices available, which are number two fuel oil and natural gas-the cleanest option.

“It’s pure economics,” said Mechanical Systems Manager Curt Stainbrook. “We pay a premium to burn natural gas exclusively. There are months when natural gas is cheaper. In the dead of winter #6 is cheaper. To quantify that-we compare the prices monthly.”

Macalester has three burners which supply steam to the heating system, the largest of which can pump 50,000 pounds of steam per hour-enough to heat the entire campus by itself. This burner uses only natural gas and #2 fuel oil, the type of oil that is used for residential home heating. The other two burners are smaller and older, and can alternate between #6 fuel oil and natural gas.

According to Mike O’Conner, Mac’s chief engineer, Macalester is the only ACTC school that burns #6 fuel oil, and #6 fuel oil burners are no longer allowed to be constructed under Minnesota State law. The old burners here are grandfathered in.

When it is especially cold during the winter, Macalester is occasionally curtailed by XCEL energy to switch from natural gas to an alternate source of fuel because the Energy Company must continue to supply residents in the area that have no choice but natural gas to heat their homes. At this point, the college can choose between fuel oil #2 or #6.

In most cases, the choice has been to go with the more polluting #6, because its cost is about one-third of the cost of #2.

“It is a financial decision by the college. No one has said to us, we need to stop burning #6,” O’Conner said, and they generally don’t have the budget to use #2 fuel oil.

“We don’t take this lightly, and we don’t always burn the cheapest [option]. If it’s close we’ll burn natural gas, but we work within the guidelines we’re given,” Stainbrook said.

In considering Macalester’s environmental footprint, limited resources must be allocated to do the most good. Perhaps money spent on conservation reduces the overall impact more than switching the type of fuel the college uses. However, a 65-foot smokestack can only push the problem so far downwind, and #6 fuel oil is the most polluting heating option the college can choose. It’s something to consider.