Still, the income is welcome and also frees the city from its obligation to pay for the disposal of greenhouse gases emitted by the landfill, said Public Works Director Dave Mumford.

The city had saved more than $700,000 to deal with waste gas before signing the contract with MDU, Mumford said, but has since put most of that money into the Public Works budget.

“That’s one of the real positives for us,” he said. “We don’t have to keep that money sitting there in reserve.” The $88,000 in sales proceeds has gone directly into the city’s general fund, as will all future profits.

Hood said the project has been beneficial for MDU, too, despite the depressed market for natural gas. Even though it’s a little more expensive to capture methane at the landfill than it is to sink a conventional gas well, many wells play out in a year or two, while the landfill project has a life of at least 40 years, he said.

The carbon credits are also an important consideration. They are awarded for preventing the release into the atmosphere of methane and other greenhouse gases, and the credits can be bought and sold in special carbon markets. Though the credits are speculative, they are considered valuable because of the likelihood of future government regulation of greenhouse-gas emissions.