Chapter 7: Safety and Emergency
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Accidents and injuries dont just happen, they are caused. Behind every accident is a chain of events that leads up to an unsafe act, unsafe conditions, or a combination of both. Safety in the workplace should be everyones concern. Communication between supervisors and employees generates ideas and safety awareness that leads to accident prevention. Safety programs, safety manuals, and safety meetings are essential in providing the lines of communication that lead to a safe, accident-free workplace.
Dangerous situations can be associated with five main gases that are produced
in livestock and poultry buildings and manure storage structures. These gases
are listed in
Ammonia (NH3) is released from fresh manure and urine and during anaerobic decomposition. Ammonia levels tend to be high in buildings where manure is not regularly and thoroughly removed. Examples include buildings with litter, solid floors, or scrapers where manure is spread over the floor. Heated floors can increase ammonia release. Furthermore, when pH levels are higher than 8.0, ammonia is more susceptible to being released. Ammonia is very soluble in water, therefore liquid manure systems tend to release less ammonia. Building ventilation also affects ammonia levels in the air. Concentrations in ventilated hog buildings have been measured as high as 35 ppm (slightly irritating to the eyes and nose) and in unventilated buildings as high 176 ppm, which can produce extreme discomfort.
Death of animals in closed confinement buildings following a ventilation-equipment failure (such as a power failure) is due in part to excessive carbon dioxide. Carbon dioxide (CO2) is released by unvented heaters, through livestock respiration and manure decomposition. In fact, most of the gas in bubbles coming from stored manure or lagoons is CO2. Vigorous agitation of stored manure can also release a large amount of carbon dioxide in a short time period.
Carbon monoxide (CO) can cause workers to develop headaches and experience chest pain. Pregnant women should be aware of the potential health hazard this gas poses to a developing fetus. Carbon monoxide is rare in confinement buildings, but can accumulate in areas with poor ventilation such as swine farrowing rooms and nursery buildings. Evidence of carbon monoxide overexposure among livestock may first appear as aborted litters and stillbirth. The main sources of CO are heaters (LP-fired, radiant brooder, or space).
Hydrogen Sulfide (H2S) is the most toxic gas generated from the storage liquid manure storage. Exposure to 200 ppm for an hour can cause headaches and dizziness; 500 ppm for 30 minutes can cause severe headaches, nausea, excitement, or insomnia. High concentrations of 800 to 1,000 ppm can cause immediate unconsciousness and death through respiratory paralysis unless the victim is moved to fresh air and artificial respiration is immediately applied. Be aware even the characteristic rotten-egg smell of hydrogen sulfide does not give adequate warning. The sense of smell is rapidly fatigued by the gas and high concentrations do not give a proportionately higher odor intensity. Also note that dangerous concentrations can be released by agitation of stored liquid manure. Concentrations reaching 200 to 300 ppm have been reported in buildings a few minutes after starting to pump waste from a storage pit and can be as high as 800 ppm during vigorous agitation.
Methane (CH4) is a product of manure decomposition under strict
anaerobic conditions, such as those found in an anaerobic or biogas digester.
It is insoluble in water, lighter than air, and thus will accumulate in stagnant
air corners in the top of enclosed pits or buildings. Methane is not toxic,
but at high concentrations may cause an asphyxiating environment. Methane concentrations
in confinement housing is normally well below the levels that may be explosive
- If there is a pulse, continue mouth-to-mouth breathing every 5 seconds (12 per minute).
- If there is no pulse, start CPR (cardio-pulmonary resuscitation) immediately.
Training courses for rescue breathing and CPR are available through local Red Cross and Cooperative Extension Service centers. These courses provide the training and practice necessary to perform CPR.
Health problems associated with poor air quality include coughing, phlegm production, wheezing, chest tightness, headaches, shortness of breath, eye irritation, sneezing, runny nose, and nasal congestion. Problems are usually greater the more time a worker spends in the presence of the contaminant and the greater the concentrations of airborne contaminants. In addition, some people are more susceptible than others.
Health problems may be chronic (lasting a long time) or acute (severe but short
term). Since chronic and acute problems can be mistaken for other health problems,
such as the flu or allergies, the work environment is often overlooked as a
cause of the symptoms and precautions are therefore not taken.
You should consider safety when constructing, operating and managing animal waste management systems. The following major safety points should be considered when installing and operating manure equipment, structures, or systems:
| Describe several safety precautions in regards to vehicle operation, heavy equipment, PTOs, and hydraulic systems. |
Only employees with a current, valid N.C. drivers license should drive vehicles. In the case of specialized vehicles, only trained operators should operate the vehicles. The driver of the vehicle should inspect the vehicle prior to operating it.
All employees must lock-out/tag-out any piece of equipment they are working on where the unexpected energization, startup, or release of stored energy could occur. In case of electrocution, turn off power to the electrical source or use an insulated implement, such as a piece of wood, to separate the victim from the source. Do not attempt to pull a victim away from the electrical source with your bare hands.
The following should be the responsibility of the site supervisor:
The Safety Program should include:
There should be a person available at all times with first aid training in:
There should be adequate, readily available first aid kits and supplies on site. Emergency telephone numbers must be posted by telephones.
Suitable facilities for quick drenching or flushing of the eyes and body should be provided in areas where the eyes or body of any person may be exposed to injurious chemicals and materials.
The following are the responsibility of the employer:
The following are the responsibility of the employee:
Employees should use the appropriate personal protective equipment, or protective devices, provided for their work. Before starting work, these items should be inspected by the employee to ensure that they are in safe operating condition. These items include, but are not limited to:
Everyone should observe the following guidelines to avoid possible injury when lifting and carrying objects:
Wastewater contains pathogens (disease-causing organisms). Hence, good personal hygiene is very important!
Each facility may want to consult a physician or the local health department to determine the need for immunizations for the employees working at the site. Adult tetanus and diphtheria should be given routinely every 10 years, or at shorter intervals when injury occurs.
A confined space is defined as a space that has limited means of entry and exit, has an adequate size and configuration for employee entry, and is not designed for continuous worker occupancy. The tanks designed for storage, transport, and application of wastes are classified as confined spaces and fall under the jurisdiction of the North Carolina Department of Labor, which is the agency that enforces the Occupational Safety and Health Act (OSHA). Under new OSHA regulations, there are certain confined spaces that require a permit for entry. A permit-required confined space is defined as a confined space that has one or more of the following characteristics:
If a facility has permit-required confined spaces, to be in compliance with the new OSHA regulations, a written confined space entry program must be developed and implemented. Enclosed facilities which are used to handle wastewater or wastewater solids, such as the tanks and/or tanker trucks, would fall under the permit-required confined space regulations. Do not enter a permit-required confined space without proper training, equipment, and support personnel. (The confined space regulations can be found in the Code of Federal Regulations 29 CFR 1910.147.)
| Describe the safety actions that must be taken when working in a space that does not require a confined space permit. |
When working in a space that does not require a confined space permit, the following safety actions must be taken:
It is important to be fire conscious in the outdoor environment. Employees should be knowledgeable of the fire conditions at the site and operate accordingly. Poor site maintenance, worn or defective electrical systems, and welding and cutting may contribute to dangerous situations. The following precautions should be observed:
Emergency action plans are required to meet current animal waste management regulations. Using resource lists in Appendix A, you should develop an emergency action plan for your waste handling system. This plan will be implemented in the event that wastes from your operation are leaking, overflowing, or running off the site. You should NOT wait until wastes reach surface waters or leave your property to consider that you have a problem. You should make every effort to ensure that this does not happen. This plan should be available to all employees at the facility, as accidents, leaks, and breaks could happen at any time. Your plan should follow this format: (1) stop the release of wastes; (2) assess the extent of the spill and note any obvious damages; (3) contact the appropriate agencies; and (4) implement procedures to rectify the damage and repair the waste management system.
- add soil to berm to increase elevation of dam
- pump wastes to fields at an acceptable rate
- stop all additional flow to the structure (waterers, flushing system, etc.)
- call a pumping contractor
- make sure no surface water is entering storage structure
* Note: These activities should be started when your lagoon level has exceeded the temporary storage level (see Chapter 2).
- Runoff from waste application field actions include:
- immediately stop waste application
- create a temporary diversion or berm to contain the waste n the field
- incorporate waste to reduce further runoff
- evaluate and eliminate the reason(s) that caused the runoff
- evaluate the application rates for the fields where runoff occurred
- Leakage from the waste distribution system:
- pipes and sprinklers actions include:
- stop recycle (flushing system) pump
- stop irrigation pump
- close valves to eliminate further discharge
- separate pipes to create an air gap and stop flow
- repair all leaks prior to restarting pumps
- flush system, houses, solids separators actions include:
- stop recycle (flushing system) pump
- stop irrigation pump
- make sure no siphon effect has been created
- separate pipes to create an air gap and stop flow
- repair all leaks prior to restarting pumps
- Leakage from base or sidewall of lagoon or earthen storage structure. Often these are seepage rather than flowing leaks* possible action:
- dig a small well or ditch to catch all seepage, put in a submersible pump, and pump back into lagoon
- if holes are caused by burrowing animals, trap or remove animals and fill holes and compact with a clay type soil
- other holes may be likewise temporarily plugged with clay soil
* Note: Problems with lagoons and earthen storage structures require the consultation of an individual experienced in the design and installation of lagoons for permanent repair measures.
- Did the waste reach any surface waters?
- Approximately how much was released and for what duration?
- Any damage noted, such as employee injury, fish kills, or property damage?
- Did the spill leave the property?
- Does the spill have the potential to reach surface waters?
- Could a future rain event cause the spill to reach surface waters?
- Are potable water wells in danger (either on or off the property)?
- During normal business hours, call your DWQ regional office; after hours, call this emergency number:
1-800-858-0368. Your phone call should include: your name, facility, telephone number, the details of the incident from item 2 above, the exact location of the facility, and the location or direction of movement of the spill, weather and wind conditions, what corrective measures have been undertaken, and the seriousness of the situation.
- If spill leaves property or enters surface waters, call local EMS (see Appendix A).
- Instruct EMS to contact local Health Department.
- Contact CES, local SWCD office, and local NRCS office for advice/technical assistance.
- If none of the above works, call 911 or the Sheriffs Department and explain your problem to them. Ask them to contact the agencies as listed above.
The emergency action plan must include provisions for emergency spreading or transfer of waste from all waste storage structures in the system. This may include emergency pumping or spreading (to prevent overtopping of a storage structure) during periods when the soil or crop conditions are not conducive to normal spreading or application. DWQ must be contacted for guidance to land apply waste in this instance. You should consider which fields are best able to handle the waste without further environmental damage. Application rates, methods, and minimum buffer distances must all be addressed. If transferring waste to another location for application, consider the limitations that may be involved with the transfer of waste to that site and application considerations at that location.
The emergency action plan should be available and understood by all employees at the facility. The main points of the plan (order of action) along with the relevant phone numbers should be posted by all telephones at the site. A copy should also be available in remote locations or vehicles if the land application sites are not close by the facility office. It is the responsibility of the owner or manager of the facility that all employees understand what circumstances constitute an imminent danger to the environment or health and safety of workers and neighbors. The employees should be able to respond to such emergencies and notify the appropriate agencies of conditions at the facility.