One of the largest environmental disasters in North Dakota took place silently, perhaps over decades, below downtown Mandan.
When the city broke ground for a new law enforcement center in the 1980s, workers discovered a big problem: massive pools of diesel fuel.
The culprit was Burlington Northern Santa Fe Railroad, which has a rail yard just south of Main Street, and had been spilling or leaking fuel for years.
Thus began a legal battle that wasn't settled until 2004, and the cleanup has been going on for more than a decade.
Walking down the street, you don't notice anything unusual, unless you know what to look for. Inconspicuous little structures like this hide manifolds that take in diesel fuel pumped from underground wells in a six block area of some of Mandan's prime real estate. Until Burlington Northern Santa Fe agreed to put $24 million in a remediation trust fund, downtown development came to a virtual halt because banks were reluctant to invest.
"A lot of the property owners in the downtown area had trouble borrowing money to either buy or sell property in the downtown area because of the contamination that was existing," said Jim Neubauer, Mandan city administrator.
Had the spill occurred on undeveloped land, it might have been simple to dig up all the soil and replace it. But what can you do in the middle of a city without major disruptions?
"It is very complicated geology in this area, so putting this system together so it's as effective as it has been was quite an undertaking," said Scott Radig, state health department.
It took more than a year to install 280 wells, 15 manifolds, and set up three collection buildings where all the recovered fuel ends up and is shipped off. The cleaner fuel is used for heating. The leftover sludge goes to an industrial dump in Sawyer. So far, those wells have sucked up more than a million gallons.
"The biggest compliment we have now is that people ask, 'Oh, is the remediation system still active?' And we say, yes it is. And if you don't know it's still active, that's a good thing. That means we're not disrupting traffic, we're not disrupting your business. And you're able to conduct business more fluidly," Neubauer said.
This pawn shop is one of several businesses with a pump in the basement. Workers say the clean up has never interfered with their business.
"Every once in a while, you hear a slight suction noise. But it's never loud enough to interfere with anything. Plus our sales floor is upstairs, and everything's downstairs, so you don't notice anything," said Mario Feist, First National Pawn.
Even though the job isn't finished, some new structures have sprung up on the affected property. And one-third of the wells will be shut down by summer.
"Once we start closing off the wells, removing the manifold buildings, I don't really think the citizens here will see much difference at all. It's just that it will be clean and a much better environment for development in the future," Radig said.
The goal is to have the cleanup completed in another two years.
Even though the wells are recovering far less diesel than they used to, those in charge say they want to keep them in place for a few wet cycles, when the city gets a lot of rain. That way, when the water table rises, so will any fuel, and they'll be able to retrieve it or discover that it's finally cleaned up.