Manure Manager

Features Regional Regulations
Producers face safety hazards when pumping

April 6, 2010  by Manure Manager

April 1, 2010 – News
reports surfaced last fall detailing flash fires and explosions in livestock
buildings while liquid pit manure was being agitated and pumped.

April 1, 2010 – News
reports surfaced last fall detailing flash fires and explosions in livestock
buildings while liquid pit manure was being agitated and pumped.

For this reason,
University of Illinois Extension staff are urging caution when agitating and
pumping manure from pits beneath buildings. So far, this phenomenon has
occurred mainly in pits under swine buildings that have foam above the manure
in the pit.

“While not all pits are
experiencing foaming issues, several Midwestern livestock producers have
reported their liquid manure pits developed a layer of foam from one to five
feet above the manure,” said Ted Funk, University of Illinois Extension
agricultural engineer. “This layer of foam is full of gas bubbles, mostly
methane and carbon dioxide – the methane making the mixture flammable. These
gases are created from the slow decomposition of manure in the pits.”

Agitating these manure
pits without proper precautions can lead to flash fires and explosions in
ventilated facilities. “When the manure is agitated or stirred during pumping,
the rate of gas release from the manure will be drastically increased. There is
also a release of hydrogen sulfide, which is extremely toxic,” Funk said.


The generation of these
gases from manure agitation is unavoidable, but the risks can be controlled.
Adhering to strict safety protocols can minimize these risks, especially when
they are used with proper ventilation and agitation practices.

To minimize the risk of
injuries and flash fires, University of Illinois Extension staff is
recommending manure handlers adhere to the following steps:

  • Review your emergency
    action plan with all workers and have emergency contact numbers available at
    the site.
  • In particular, liquid manure
    pits with foam should be worked very cautiously and agitated slowly.
  • Prior to agitation or
    pumping, turn off electrical power to any non-ventilation equipment, and
    extinguish any pilot lights or other ignition sources in the building.
  • Fully open all ventilation
    curtains or ventilation pivot-doors.
  • Run ventilation fans at
    maximum speed.
  • Ensure that all people are
    out of the building and clearly tag all doors, noting that the building is
    unsafe for entry during agitation and pumping.
  • Always start the agitation
    process slowly and increase speed over time. Agitate the manure keeping the jet
    of pressurized manure below the liquid surface. Don't let the jet of manure
    strike walls or columns in the pit.
  • Continue maximum
    ventilation for 30 minutes after pumping has ended before re-entering the
  • NEVER enter a building or
    manure storage structure when liquid manure is being agitated or pumped. Put up
    signs or hang tags to keep people out.

“While we are not sure
exactly what has led to these problems, we think the above practices will
minimize any accidents,” Funk said. “Several land grant universities have begun
research to try to determine causes and solutions.”

Producers who have had pit
foaming this season can contact University of Illinois Extension staff to
contribute details of their observations. Extension welcomes information that
may help find solutions to the problem of manure foaming.

University of Illinois
staff are available for questions or additional information:

Ted Funk –

Matt Robert –

Randy Fonner –


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