Pig barn explosion cause still unknown
Sunday, September 30, 2012
by BETTER FARMING STAFF
Investigators late Monday were still working to determine the cause of an explosion at a pig barn near Seaforth that seriously injured two males.
Carol Gravell, public relations officer for the Ontario Fire Marshall’s Office, said an investigator and a fire protection engineer were working at the scene but they had not determined what caused the event.
In a news release issued late Monday, police identified the injured victims as Dann Eedy, 25, and Joshua Purdy, 15. The explosion took place about 12:30 p.m. Sunday on a farm on Bridge Road, east of Seaforth. Police say the injured males, both from Huron East, were draining manure inside the barn when the explosion occurred. Both were airlifted to London’s Victoria Hospital in serious condition.
Since 2009, there have been a number of pig barn explosions in the US Midwest in barns where foam on top of manure pits was present. The foam traps gases that can be released when manure is agitated or pumped and, when ventilation cannot keep methane from accumulating to four to five per cent of air volume, it can explode. Human injuries but no deaths have been associated with the blasts in the US. In September 2011, a barn in Iowa exploded killing 1,500 pigs and injuring one worker. What causes the foam to accumulate is a mystery.
Doug Richards, a swine grower finisher specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs in Clinton, says there have been a number of theories put forward about foam cause but nothing has been isolated.
“There’s probably quite a few different things that cause it,” he says. At first, he says, people thought it might be deep pits but then it started showing up in shallow pits. People theorized it might be the use of distillers dried grains (DDGs) but then it showed up in barns where DDGs had never been used. In side-by-side or double-long barns where feed, populations - everything - is the same the foam might show up in one pit and not the adjoining pit.
Foam or not, Richards says anytime you work with manure, ventilation should be at maximum levels “Any time you’re handling manure, whether it’s tanking or stirring or pulling plugs or whatever, you’ve always got to be aware.” he says, adding that the ministry issue two or three bulletins a year to keep the issue in front of producers. Those advisories can be found on the OMAFRA website (http://www.omafra.gov.on.ca).
Among other things, OMAFRA advises that, if there is a perceived problem with manure gas in a barn, people should be kept out.
Larry Jacobson, a professor and extension engineer at the University of Minnesota, has done extensive research on foaming in manure pits in pig barns. Recently, he was part of a team that came up with a way to control foam. The team recommends producers add Monensin Premix to pits. The product, usually used to reduce bloat in cattle, decreases acetic acid levels, a precursor for methane. Their fact sheet, including recommended treatment levels, can be found at www.mnpork.com(select farmer resources tab and then MPB check off research).
Jacobson says, “We really don’t know the underlying reason why manure just starts to foam spontaneously.” He adds that you don’t have to have foam present to have a dangerous or explosive mixture of gases in a barn during a pumping or agitating operation. “When you’re pumping, there’s a lot of gases released,” he says.
“The standard protocol is to make sure that your are moving the maximum amount of air in the building while you’re doing this and, we always say, when you’re doing this never have people in the building. We discourage even having pigs in buildings but we understand . . . that may not be possible.”
The Seaforth explosion is being investigated by the Ontario Ministry of Labour, the Ontario Fire Marshall’s Office and the Huron County OPP. BF