WAHPETON, N.D. — There's something lurking in eastern Richland County. You can't see it, nor can you hear it. But every once in a while, you can definitely smell it.

In recent weeks, residents in Wahpeton and Breckenridge, Minn., have been dealing with the intermittent arrival of an overpowering stench that hangs over the area — offending some and making others downright queasy.

The smell gets into cars and can even seep into buildings. Residents have different ways of describing it, but they all agree on one thing: It’s pretty vile.

Kristi Severson said it smells "like sewer" and that it has been strong enough to make her sick.

"It gave me a migraine; my stomach was upset — it's just nasty," she said. "You can't even walk outside, you basically have to cover your mouth."

Farmer Gary Friskop describes the odor as a mix of sulfur and rotten eggs.

Others had simpler descriptions.

"Basically, crap is what I would say it smells like," Noah Dobmeier said.

The frustration goes beyond the foul smell, however. While officials have pinned the origin of the scent to the Minn-Dak Farmers Cooperative beet processing plant a few miles north of Wahpeton, they haven’t been able to identify the exact cause.

For weeks now, state environmental officials and the cooperative have been trying to track down the source of the smell to no avail. Minn-Dak blames the “intermittent nature” of the smell for the struggle to pinpoint its origin.

For a while, the cooperative thought it had fixed the issue when it changed its waste process. The odor was greatly reduced for a while, but it soon came roaring back.

The North Dakota Department of Environmental Quality said it is taking the smell seriously, and officials have been investigating at the plant anywhere between two and four times a week. The department has been taking samples of pond units at the plant, which could be what's causing the smell, but as of Friday they still weren’t certain.

The mystery isn’t just bothering residents. In a news release last week, Minn-Dak expressed frustration with how difficult it has been to identify the source of the odor.

The air was clear Friday, Dec. 6, but when the smell does come it has been so bad in cases that it has interfered with everyday life for locals.

“I had a friend of mine who was trying to sell his house … it smelled so bad that it killed the sale,” Friskop said. “You can't have that going on; they’ve got to figure out what it is.”

While beet processing can create an odor, city officials and many locals say it has been exceptionally bad for the past few weeks.

"A food processor is going to have some odors from time to time,” said Chris DeVries, community development director for the city of Wahpeton. “But for some reason at this time, it's to an extent that we have not seen before.”

DeVries said the city is working with the plant to figure out what's going on, but since the plant is outside city limits, there's only so much they can do.

"We can only press upon them how much it's affecting our city and our residents and hope they can take that to heart and do what they need to do," he said.

Until the plant finds a source, it can't fix the issue, which means residents, like Severson, will have to deal with the stink for a little while longer.

"It's terrible. I've never smelled something so bad," she said.