Manure Pit

A tractor-powered agitator drew material from the bottom of the 12-foot pit and sprayed it through a nozzle onto the top.

Silage harvest is starting soon, which means dairy farmers will also be stirring up trouble in their manure pits.

Noxious gases can escape from a manure lagoon at any time, but the risk is especially great when it’s being agitated.

That danger was underscored last week when a 29-year-old dairy farmer and more than a dozen cattle died after being overcome by manure vapors at a Wisconsin dairy, according to The Associated Press.

The county coroner told the news service that warm atmospheric conditions likely trapped poisonous gases near the ground during manure agitation.

“It’s a reminder that we need to be very vigilant” when agitating manure pits, said Hosea Latshaw, Pennsylvania state conservation engineer at USDA’s Natural Resources Conservation Service.

On muggy days, manure gases may linger around the lagoon, said Dennis Murphy, a Penn State Extension safety specialist.

Hydrogen sulfide is a particularly potent gas and a serious concern on farms that use gypsum bedding.

The gas is heavier than air, so it can build up near the ground and in low-lying areas. That makes it especially dangerous to children and to livestock that are lying down, Latshaw said.

“On hot, humid days, it just doesn’t go anywhere,” Murphy said.

Inspectors suspected gases other than hydrogen sulfide caused the Wisconsin deaths, according to the AP.

Manure can produce more than 200 gases, including methane and carbon dioxide, according to newspaper records.

Using a portable gas monitor is the best way to know toxic gases are present.

Farmers “really need to either own one or rent one or have the ability to do some spot checks sometimes,” Latshaw said.

Buying and calibrating a gas monitor probably costs around $1,500, but the equipment can be rented more cheaply, Latshaw said.

For people who do a lot of manure agitation, “that should be a cost of doing business,” he said.

Manure haulers are starting to use gas monitors. So have a few farmers, but “not nearly enough,” Murphy said.

Manure gases can rapidly overwhelm a person. If the gas monitor goes off, “you need to take immediate action,” Latshaw said.

Children and animals should be kept a safe distance away from the agitation. Unfortunately, it’s hard to say how far away is safe.

The answer depends on the lay of the land and winds, and “every situation is different,” Murphy said.

The U.S. Department of Labor prohibits people under age 16 from entering manure pits.

Farmers should wait to agitate an outdoor lagoon until the prevailing winds are blowing away from the tractor and pumping unit, livestock areas, and the house, Murphy said.

“We always recommend that there be at least two people there” so that one person can go for help if the other one goes down, Murphy said.

Attempting to rescue the other person is usually unwise.

Several manure gas incidents have resulted in multiple deaths because family members or workers attempted to save the original victim.

Instead, if a person falls into a manure storage, call 911 and wait for responders with scuba gear to come. “You do not want to go down after them,” Murphy said.

Try to get as much air into the pit as possible. Move fans and silage blowers into place if possible, Murphy said.

If the person has collapsed near the pit and you are not feeling any effects of manure gas, you may be able to run in and drag the person to safety, Murphy said.

A Danville farmer pulled his two young sons to safety after they were apparently hit by a plume of manure gas in 2012, Murphy said.

But rushing in may not always be safe. Depending on where the fumes are, the responder could be overcome in a few seconds, Murphy said.

Gas monitors can help assess those situations, he said.

Farmers may want to move livestock away from the agitation area, especially if the manure is stored under the barn, Latshaw said.

The agitation spout will spew gases along with manure, so be mindful of where the spout is aimed, Latshaw said.

Reports of the Wisconsin incident suggested that the manure pit was very large, but the degree of risk is not influenced by the pit’s size, Latshaw said.

“There’s enough gas produced in a small manure storage to injure or kill somebody,” Latshaw said.

A larger manure pit just takes longer to pump than a small one, he said.

Agitating manure will always be a risky activity, but farmers can mitigate the risk by taking proper precautions.

Phil Gruber is the news editor at Lancaster Farming. He can be reached at (717) 721-4427 or Follow him @PhilLancFarming on Twitter.