Pumping manure pits requires care and attention to risks posed by the job. Extra care is critical in the process.
Liquid manure creates several gases including methane and hydrogen sulfide, both of which are flammable. The rate of gas release from the manure can be drastically increased when the manure is agitated during pumping. This increase is especially true for hydrogen sulfide, which can have a lethal paralyzing effect in addition to being flammable, notes Shawn Shouse, an Iowa State University Extension area agricultural engineer.
Strict safety protocols, along with proper ventilation and agitation practices, can minimize the risk of flash fires and explosions during manure pumping. Follow these tips from ISU and the National Pork Board.
• Review your emergency action plan with all workers, and have emergency contact numbers available at the site. The pork checkoff’s Pork Production System, available at http://www.pork.org/workersafety offers tips on developing and implementing an emergency action plan. It also includes sections on hazardous gasses and fires.
• 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, but leave walk-in doors locked to prevent human entry.
• 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.
• 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.
• Stop agitation when the manure level does not allow agitation below the liquid surface.
• Continue maximum ventilation for thirty minutes after pumping has ended before re-entering the building.
• Never enter a building or manure storage structure when liquid manure is being agitated or pumped.
Battling a blaze