Reducing manure-pit deaths
By David Manly
Photo courtesy of the University of Wisconsin Extension.
May 21, 2013 – Manure pits are often necessary when dealing with livestock operations, but pose a large risk to workers due to the potential for toxic gases to build to lethal levels causing unconsciousness, asphyxiation or drowning. While not a common occurrence, researchers say that a small number of people in North America still die each year in animal manure pits.
Therefore, researchers at Penn State’s College of Agricultural Sciences have published a new international engineering safety standard regarding the need for proper ventilation in manure storage facilities prior to anyone entering.
Harvey Manbeck, professor emeritus of agricultural engineering, said that such a standard is needed because while it is a well-documented hazard in agriculture, it is not very well known by the public. “There are enough documented cases of death occurring from folks entering manure storage areas when they are emptied for repair, equipment retrieval or maintenance,” he said. “And in some cases, there are multiple deaths – including members of the same family or community, where folks go to help one another in a situation that is really hazardous.”
These types of accidents usually occur when an individual goes into a manure pit without proper gear or preventative measures in place, Manbeck explained, and as a result they quickly succumb to the high gas levels present in the pit. “And if they are by themselves, that is a fatality risk. If there is a family member up above watching, and sees that happen, they would likely go down and be at risk themselves.”
Therefore, Manbeck and Dr. Dennis Murphy, an agriculture safety specialist also at Penn State, co-led an eight-year research project to create the new standard. The goal was to determine how long it would take to ventilate a wide variety of manure spaces in order to make sure that the noxious gases have been evacuated to safer levels. Manbeck adds: “The standard gives you guidance on fan size and how long you should run to reduce the risks of entering the pit.”
The American National Standards Institute (ANSI) has recently adopted the new standard – known as ANSI/ASABE S607 – in association with the American Society of Agricultural and Biological Engineers (ASABE), who published the standard in late 2011.
While it had been common knowledge that ventilation can help mitigate and evacuate the noxious gases and replace oxygen in the manure space, the standard also addresses a common problem, said Manbeck: “What was missing was how much and for how long the ventilation should be run before entering.”
While the standard has been published, the next step is to distribute and implement it in as many operations as possible, especially to those that design and build the manure pits. Following that, since ANSI/ASABE S607 only covers roughly 80 per cent of all confined manure storage facilities in the U.S., the remaining structures must be addressed – which Manbeck plans to do through a user-friendly design tool.
“The online tool can be used by builders, engineers, planners, etc… to help plan for practically any type of design situation in the field with the standard in mind,” he said. “And we hope to have it available to customers, if funding continues, around spring 2014.”