Residents throughout the Capital Region checked the bottoms of their shoes Friday morning as a foul odor left many thinking they had stepped in something.

After hours of social media speculation under the hashtag #518funk — including a brief, inaccurate attempt to blame gingko or ornamental pear trees — the state Department of Environmental Conservation concluded the culprit was a load of manure. Or, more correctly, multiple loads.

Rather than pinpoint a single cause, the department is saying there must have been multiple sources for a foul smell reported from Albany to Saratoga Springs.

"DEC received numerous odor complaints today from throughout the immediate Capital Region and DEC staff are investigating potential odor sources," the department said in a statement emailed to the press Friday afternoon.

"Due to the widespread nature of the complaints, it appears the odors are most likely coming from a variety of sites that are spreading mulch, fertilizer, manure and compost on lawns and fields, as these items can all have quite pungent orders. Due to today's low winds the odors are not dissipating very quickly."

The department recommend people call its tip line if they experience any foul odors so that it can continue to search for any potential sources. The tip line number is 844-332-3267.

The smell filled nostrils from Albany through Colonie to Niskayuna, even in Saratoga Springs and Clifton Park, with people comparing the odor to dog manure or vomit.

One cause quickly ruled out was some natural emission from trees.

Peter Bowden, spokesman for the Hewitt's chain of gardening centers, said there is no way the odor wafting over a large stretch of the Capital Region came from gingko or pear trees.

"I was mystified myself," he said. "There is no tree that's flowering that is going to do this, and the scope of it is out of control."

Susan Pezzolla, a horticulture educator at Cornell Cooperative Extension, agreed.

Gingko trees' fruit, which is notoriously smelly, does not ripen until later in the year.

Dennis Gaffney, a spokesman for the city of Albany, said he had been unable to track the odor but the city received calls nonetheless. "They do smell a kind of an earthy compost smell," he said.

The city even checked its compost facility.

"Someone went down there and took a whiff," Gaffney said. "It's not that."

The city landfill also was ruled out.

"It's a bit of a mystery at this point," he said.

Jack Cunningham, commissioner of general services for the town of Colonie, said its landfill was also not the cause.

"There are two landfills," he said. "Everybody always blames us."

The National Weather Service could provide no answers. Whatever it is, they said, it's not an act of nature.

"I smelled it coming in today," meteorologist Hugh Johnson said.

Sometimes, he said, the wind that normally dissipates landfill odors can pick up the scent just right and spread it instead.

"Usually that happens with a light northwest wind," he said.

tobrien@timesunion.com • 518-454-5092 • @timobrientu