There are different methods that are usually employed to deal with carcass when massive death of animals does occur. Animal disposal by burying is one of the most commonly used methods especially when there is a catastrophe that has claimed a large number of animals. There are both advantages and disadvantages of carcass disposal with the exercise requiring careful measures to control the effects. Burying of animals in inappropriate regions such as water catchment areas or poor methods of burying may pose a great danger to the environment. Reburying offers alternative methods of mitigating the impacts of massive burying of animals in environmentally unsafe areas but it also has its own shortcomings. This paper discusses the effect of animal reburial on the soil structure and water and also possible remedies for the same.
Effects of animal reburial on soil structure and water
The Situation at Hand
In an endeavor to supply the ever increasing human population with enough food the scale of livestock farming has increased with time. Due to various catastrophes such as floods, drought and diseases such as the deadly anthrax, foot and mouth, swine flu and others the number of animals dying when such epidemics occur is staggering. A recent case was reported in Jangrim-dong, Busan, where Tae-jong was quoted claiming that “More than 3 million animals have been culled and buried to contain further spread of the food-and-mouth disease (FMD)” (Tae-jong 1).
Catastrophes often occur unexpectedly and without warning. The number of deaths in most cases is usually higher than what the affected people can manage at the time of occurrence as Ellis Dee claimed
The disposal of dead animals as a result of recent natural disaster events such as Hurricane Floyd in North Carolina (1999), and disease related events such as the Foot and Mouth Disease (FMD) outbreak in the United Kingdom (UK, 2001), created tremendous logistical problems. (Ellis 5)
When such events occur desperate measures are usually taken to try and contain the situation before it explodes to even higher deadly catastrophe. In some of these instances big mistakes are made as Ellis claimed: “Producers were tempted to (or did) bury animals in grounds saturated with standing water, which could allow the carcass runoff to leach back into ground drinking water or local streams and tributaries” (Ellis 22) and this may lead to massive burying of carcass in places where the environmental safety may be jeopardized. When this occurs there may be the need to relocate the bio waste to the sites that are safer. But this action may have its shortcomings.
Hazardous Effect of reburial exercises
Re burying calls for opening up of the old sites, exhuming the entire carcass, massive transportation of the carcass to safer sites and the eventual refilling of the site. This activity is likely to affect the soil water and structure.
The mechanical process of exhumation opens up a closed site and exposes the bio waste to environmental factors such as rain and air. Rain water may act as an agent of transport of the already decomposed and unstable toxic waste down to lower soil layers generally referred to as leachate thereby polluting the underground water with the toxic materials. Engel et al claimed that “where vertical groundwater movement occurs, leachate from burial sites may pose a higher contamination risk to groundwater” (Engel et, al 6)
The process of excavation involves very heavy earth movers and trucks. These machines compress the upper soil layers which restricts infiltration. A report by USDA claimed that:
Restricted infiltration and ponding of water on the soil surface results in poor soil aeration, which leads to poor root function and plant growth, as well as reduced nutrient availability and cycling by soil organisms. Ponding and soil saturation decreases soil strength, destroys soil structure, increases detachment of soil particles, and makes soil more erodible. (Dept. of Agriculture 2)
when the surface soil is compacted by heavy machineries it becomes more possible for surface runoff to occur since water may not be able to seep under due to the compacted soil. The surface runoff may carry the leachate to other areas especially if the site was located in a sloppy area resulting to widespread contamination.
It is worth noting that excavation of already decomposed and unstable carcass poses even a greater risk than the original burying due to possible acceleration of leaching of bio waste into underground water as Engel et al suggested “proper disposal of livestock mortalities can be more difficult than manure management, because animal carcasses are not easily stored for long periods of time” (Engel et, al 6).
The sites for massive burying are usually large and deep and in the process of excavation a depression is created. If there is no proper filling of such depressions then thus areas become potential points for underground contaminations “runoff carries nutrients, chemicals, and soil with it, resulting in decreased soil productivity, off-site sedimentation of water bodies and diminished water quality”. The collected water absorbs the already decomposed and unstable matter and leaches to the lower layers of soil hence affecting the water on the lower soil layers.
It may be argued that the accelerated leaching transports leachate to the underlying soil layers as suggested by Engel et, al “elevated levels of biochemical oxygen demand (BOD), ammonia-nitrogen (NH4-N), total dissolved solids (TDS), and chloride were commonly found within or very near the burial trenches” (Engel et, al 6). This in turn may affect various soil organic matter, microorganisms and soil ph all of which are important in maintaining soil structure thereby affecting soil structure.
Proposed mitigation methods
Perhaps the best option is to take time to plan and put into considerations to ensure that all the precautionary safety measures are taken in place such as putting into place the logistics of transportation, excavation and burying. Pullen suggested that “The transportation of large numbers of diseased animals or carcasses requires significant planning and preparation in order to prevent further dissemination of the disease” (Pullen 5). Re burying should take the shortest time possible to reduce exposure of the site to environmental factors such as rain which may accelerate the effects.
Timing of the excavation should be properly done such that the whole process is done at a time when there are favourable weather conditions to minimise the effects. It is also advisable to consider water channels passing through the site and channel them away from the site if possible “Diversions should be built as needed to prevent surface water runoff from entering the pit. Similar diversions should be constructed to prevent liquid from leaving the burial site” (Michigan 17). This may help in minimising the leaching away of the toxics during the excavation process.
I would also recommend utmost care when excavating on sloppy areas where leaching and surface runoff may be more prevalent “Hilly land is more of a concern than flat land since it promotes more rapid surface water runoff during the spring or a heavy rainfall” (Alberta 1). It may also be necessary to asses the condition of the soil around the site and probably consider moving the soil from the site together with the carcass to ensure that the soil doesn’t spread the contamination.
Reburying is one of the options of mitigating the environmental effects of carcass burying on environmentally unsafe areas. The process of excavation poses environmental hazards such as accelerated leaching, soil water contamination by leachate which contains large amounts of ammonia which may affect soil water and compaction of soil which may affect soil structure. It may be recommended that precautionary measures such as timing the whole process such that it occurs on a dry season when hazards are much less and assessing the water bodies around the site and diverting them whenever possible. Even after the whole process is complete it may be necessary to maintain routine check up of the environment around the exhumed sites.
Alberta. Livestock Mortality Burial Techniques. Agriculture and Rural Development, 2011. Web.
Dept. of Agriculture. Natural Resources Conservation Service US Dept. of Agriculture, 2008. Web.
Ellis, Dee. Carcass Disposal Issues in Recent Disasters, Accepted Methods, and Suggested Plan to Mitigate Future Events. Carcass Disposal Guidance, 2001 Web.
Engel et, al. Carcass Disposal. A Comprehensive Review, 2008. Web.
Michigan. Standard Operating Procedures for Michigan Mass Carcass Disposal. Government of Michigan, 2004 Web.
Pullen, David. Carcass Disposal: A Comprehensive Review, 2004, Web.
Tae-jong, Kim. “Hasty, shoddy burial of animals expected to contaminate soil, water.” The Korea Times, Web.