Leaked jet fuel at MSP ‘not a hazard’

The probable cause of a jet fuel leak at the Minneapolis-St. Paul International Airport was discovered recently. The leak is thought to be coming from a valve pit on the airport’s fuel delivery system. “It appears likely there was a leak in the valve and a crack or other problem with the pit’s fiberglass liner,” said Steve Lee, emergency response team leader for the Minnesota Pollution Control Agency (MPCA).

Lee said the MPCA has been working on the problem with the Metropolitan Council Environmental Services since Feb. 15, when petroleum vapors were first detected coming from a sanitary sewer connected to the Whipple Federal Building north of the airport. Later, fuel was found in wastewater being processed at the Metropolitan Wastewater Treatment Plant, south of downtown St. Paul.

By Feb. 18, the source of the vapors had been tracked back to the airport. The Metropolitan Airport Commission (MAC), the airlines, and Aircraft Services International Group (ASIG), the airline’s fueling contractor, searched for the source of the leak. A California company that specializes in finding leaks tested the airport’s fuel lines during the early morning hours when there were no scheduled flights.

Ventilation of the sewers and interception of leaked jet fuel flowing into the sewer have largely eliminated entry of fuel vapors into the Whipple Federal Building. By Feb. 23, “contractors working for the MAC had collected 10,700 gallons of jet fuel from a sump that lies near a pedestrian tunnel running between concourses A and B” of the airport’s main terminal, Lee said. “The sump is about 800 feet from the valve pit where the fuel is believed to have leaked.”

“ASIG has now taken over the lead in recovering the lost fuel and developing a work plan to find out how the fuel moved between the valve pit and the sump. And, the MPCA is requiring the Metropolitan Airports Commission, the airlines, and ASIG to recover all the lost product from the ground.” Lee said the leaked jet fuel poses no hazard to the flying public or to other people at the airport.

Local environmental activist Susu Jeffrey is skeptical, however. “The fuel leak poses a risk to the 18 million people who drink out of the Mississippi,” she said recently by phone. “Once again we’re putting our waste into the drinking water supply.”

“The problem is just that the airport is in the wrong place,” she explains. Part of the reason the leak traveled so far underground, she surmises, is because of the network of old channels of the Mississippi river that snake around beneath the airport grounds. “It’s not as though the airport is sitting on limestone on top of sandstone,” she says. Much of the airport rests atop silty river deposits, which were formed by the rivers that frame it, and which bear the geological scars of the waters’ action.

“If you look at the geology of Minnesota, most of the state tilts towards the confluence of the Mississippi and Minnesota rivers,” she says. “So you have much water creating channels under the airport. What’s going on down there is like Swiss cheese.” Because of this, any runoff from the airport has an unusually good chance of entering both the major rivers and other water channels, such as public sewers. (Jefferey’s knowledge of the geology and hydrology of the airport stems from her efforts to preserve the Camp Coldwater spring, which also runs under the airport grounds.)

A related issue that Jeffrey doesn’t think gets enough attention is mid-air dumping of jet fuel. Commercial airliners are only allowed to land with a certain amount of fuel in their tanks because the added weight of excess fuel could make the plane difficult to control on approach. As a result, pilots routinely jettison excess fuel before landing.

“I know people living in Richfield, on the approach to the airport, who, when they use their patio furniture for the first time every summer, find it covered with a thick, greasy film,” she says. “The airport authorities say that the fuel just evaporates, but it doesn’t just disappear. It’s going to stay around in the atmosphere.”