The gas fumes weren't bad Monday when Tom Fetsch turned off the lights and locked his station, possibly for good.

But they have been mighty powerful off and on, which made the decision to shutter his north-side Best Stop store an easy one.

A gasoline spill discovered under the station and a nearby restaurant this fall has flowed through virgin soil faster than scientists thought it would, making them very eager to start cleaning it up.

So Fetsch has decided to get out of the way.

"I said all along that if it gets to the point where I'm uncomfortable, I'll pull the plug,"Fetsch said. "We were starting to get strong smells in the store. I'm doing the best thing for my customers. We could maybe tough it out till who knows when, but … this was the right thing to do."

The station will remain closed throughout the cleanup of the spill, which could take years. Fetsch said the building might even be torn down to make remediation easier, though that's not his call. The bricks and mortar are owned by J&L Development, whose partners could not be reached Monday for comment. The Tribune tried to reach them three times.

About 700 gallons of gasoline already have been recovered from the spill at test wells, and no one's sure how many more gallons are under there. The wells at Best Stop have been producing 20 to 30 gallons of gas a day, North Dakota Department of Health scientist Leon Vetter said. He said there is no new gas leaking into the ground at the north Bismarck site, but the unknown quantity that escaped into the soil is moving around. It's made its way to a trench between the gas station and Bank Center First. So far, the bank is OK.

The problem was discovered this fall, when a plumber in the basement of a nearby restaurant found gas in each of the building's five sump pumps. That led investigators from the state health department to Best Stop, on East Interstate Avenue. They spotted a leak in one of the lines, which was quickly repaired.

Fetsch believes the gas from his leaky line was contained, and he says the underground spill could have occurred at the station prior to his ownership. However, he also agreed that speedy remediation was desirable.

"Right now the best thing for the cleanup is for us to close," Fetsch said. "If they want to pull up the tanks and the lines, if that's the best thing, there's nothing to stop them from doing that."

Bids for the cleanup were let in November, and the health department is still reviewing the submissions it received. The down time between discovery and cleanup hasn't been cheap, though. About $300,000 has been spent to rid the restaurant of problems and sink test wells. Right now, Fetsch is on the hook for the first $5,000, and could end up spending $20,000. The state has insurance that covers 90 percent of the cleanup cost up to $200,000, and then 100 percent up to $1 million.

Vetter said cleanup will likely go more smoothly than what was first thought because Fetsch closed the store.

"We'll be able to dig out more soil that way,"Vetter said. "It's easier to do that than clean (spills) up in place."

More test wells will be dug this week in the trench between the gas station and the bank.

"In the last couple of weeks, a huge amount of gasoline has been found in that trench that wasn't there previously," Vetter said. "Something is moving through the system, and we're not quite sure how it's getting there. The geology suggests gasoline shouldn't be moving that fast through the soil there, but it is."

Meanwhile, above ground, when the north Best Stop ran out of gas Monday, that was it.

"I don't know if we'll ever reopen this location," Fetsch said. "It's unfortunate we had to close. We have some good, loyal, friendly customers; hopefully they'll come shop with us at our other locations."

Best Stop also has stores on 14th Street and Broadway Avenue in Bismarck, and across from the Stage Stop in south Mandan.

"In a way you feel like you're letting (customers) down, but really you're doing what's best for them and yourself,"Fetsch said. "We've always put the customer first when it comes to making decisions for our company."

(Reach reporter Tony Spilde at 250-8260 or tony.spilde@bismarcktribune .com.)