Spring and fall are busy times of year for agriculture operations, whether preparing fields for the new cropping season or harvesting those crops. In many cases, those two times of the year also involve pumping manure to evacuate the pits and fertilize the soil.
It’s a process many of us have performed multiple times, so it’s easy to understand how one could become complacent while working around these dangerous spaces. Let’s take a moment to examine some of the common hazards.
Hazards and risks with manure storage
The potential hazards of manure pits, tanks, basins, ponds and lagoons include:
1. Risk of falling into manure and drowning
Equipment and vehicle operators can drive into manure storage ponds, lagoons and pits. Earthen edges around basins, ponds or lagoons may appear deceptively “solid” or become invisible to workers when edges blend in with surroundings. Risk increases during low light conditions, for example, during evening work or in poorly lit areas. Tractor-scraper drivers can tumble into pit openings from push-off platforms or ramps. Individuals walking or working at ground level near boundaries of pits, separator lagoons and sometimes other types of manure storage can also stumble and fall into manure. Unstable or poorly maintained ladders can also cause falls into pits.
2. Manure gases can suffocate, poison or ignite
Stored manure consumes oxygen and releases hazardous gases including hydrogen sulfide, carbon dioxide, methane and ammonia. The low oxygen and accumulated gases above the manure can swiftly overcome workers and farmers without warning. Atmospheric conditions in and around pits and other manure containment may be safe on some days and deadly on others. Do not rely on past luck with uneventful entries. Your sense of smell will not keep you safe from manure gases. High levels of manure gas are released during activities that disturb the manure, such as pumping and agitating it. Even sludge and residue at the bottom of drained pits, tanks and other containment can emit dangerous amounts of manure gases. Gas production will increase at warmer temperatures. Some manure gases, like methane, are potentially ignitable and explosive.
3. Moving parts on machinery and equipment
Workers are at risk for amputations, broken bones, getting crushed and other severe injuries when working around manure pumps, agitators and rotating shafts (e.g., power-takeoffs/PTOs). These and other hazard sources can quickly snag and draw in a worker’s loose clothing, long hair, jewelry, fingers or feet.
4. Bacteria and other pathogens
Solid or liquid manure harbors pathogens that can cause infection or illness through direct contact. Getting splashed in the eye or mouth may transmit pathogens and cause serious infection.
In knowing the risks, put measures in place to prevent injury or death from occurring when emptying manure storages.
Drowning preventions
Ensure the manure pit, pond, basin and lagoon boundaries are visible. Safely fence or block off boundaries to prevent unsafe access. Lock gates and access. Add appropriate safety covers for tanks and access openings to manure pits and other confined spaces to keep people out.
Post and maintain appropriate warning signs around manure storage. Use reflective tape or bright paint for better visibility in low light.
Prevent rescuers from becoming additional victims. Make plans on what to do should emergency rescue become necessary. Any individual involved in rescue or retrieval must have special training and equipment and follow all applicable safety procedures.
Manure gas abatement strategies
A key prevention solution is to ensure effective ventilation is in place. Mechanical ventilation may be necessary to replenish oxygen. If workers must enter pits, tanks or other manure storage, purchase or rent a fresh air calibration to measure oxygen, hydrogen sulfide and methane or the lower explosive limit (LEL). Follow established procedures on how to safely and effectively conduct gas monitoring before entry.
Other injury and illness prevention
Mechanical: Ensure barriers and guards that cover dangerous moving parts are in place and are maintained. Review as a team how machinery and equipment, such as pumps and agitators, work. Discuss and review proper lockout/tagout procedures and how to safely start up, use, shut off, unclog, retrieve, clean and repair equipment. Provide locks and other safety equipment. Follow safety guidance specific to the equipment being used.
Pathogens: When contact with manure is unavoidable, wear proper safety gear such as eye protection and face shields that can prevent splashed manure from contacting your eyes and mouth. Other personal protective equipment (PPE), like coveralls and gloves, can prevent pathogens from infecting skin. Always follow correct hand washing techniques and other hygiene practices that help reduce the spread of contamination to food, eyes and work surfaces.
Agitation precautions
Do not enter the barn while manure is being agitated in the pit below. Instruct workers and all visitors on the farm to stay out of the building while the manure is being pumped and agitated. If possible, use lockout tags to remind everyone of the activity taking place.
Set ventilation rate at the maximum level and adjust fresh air inlets to meet the needs of the barn’s exhaust fans, but do not open doors and windows that are not normal fresh air inlets, as this unplanned area of incoming air may short-circuit the system, causing stagnant areas with little or no air movement.
Be extremely cautious if the manure in the pit is foaming. Foam contains high levels of methane, and agitating the manure will break the foam bubbles, resulting in methane buildup in the building that can cause fires and explosions.
Personal protective equipment
If you must enter a manure pit, you must wear a self-contained breathing apparatus, safety harness with lifeline, eye protection and face shields, and coveralls, gloves and protective footwear.
Train and standby to assist in rescue
At least two other personnel should be on hand to assist in a rescue, if necessary. At no point should a rescuer enter a pit without the proper breathing equipment themselves; otherwise they run the risk of becoming a victim themselves. Prior to the worker entering the pit, discuss as a team what emergency steps you will take should the worker find him or herself in trouble while in the pit. What emergency steps will you take? Document the steps and have each worker sign off on this document.
Signage
Post signage at applicable manure pits as a visual reminder for all workers and visitors to the dairy.
