The swine industry is faced with discovering innovative and economical ways to dispose of dead swine. This need has been brought on by the disappearance of rendering plants, concerns over potential ground water pollution from burial, and the economic and environmental issues of incineration. Composting of dead animals is an option that is available to Ohio swine producers.
Composting offers an economical and environmentally friendly way to use swine mortalities, and recycle the nutrients contained in the animal carcass. Composting is a natural process in which the swine carcass is biodegraded by bacteria to avoid pollution of air and water.
The process of composting dead animals allows bacteria and fungi to decompose the animal carcasses in an aerobic environment. Providing oxygen to this environment allows microbes to decompose the animal carcass without the production of objectionable odors and gasses. When done properly, composting destroys disease causing bacteria and viruses, and prevents problems associated with flies, vermin, and scavenging animals at the composting site.
Ohio's Swine Composting Development Team has identified four basic objectives for composting swine mortalities in Ohio. These objectives are:
Selecting the proper location for the composting facility is the first step in meeting the objectives listed above. Several factors must be considered when siting facilities for composting dead animals. Water quality, public perception, nuisance concerns, bio-security issues, and traffic around the compost area are some of the factors discussed below.
A number of organic compounds are produced during the composting process. Some of these compounds may pose water quality problems if allowed to leach out of the compost before the composting process is completed. However, these compounds are destroyed when subjected to the complete composting process.
Locating the composting facilities away from steams, lakes, and wells will minimize the risk of runoff entering these water supplies. Any runoff from the compost area must be collected and treated before entering a water resource. Treatment can take place through properly designed vegetative filter strips, infiltration areas, or other accepted treatment methods. Diverting surface water away from the composting facility will minimize the amount of runoff water generated from the compost site. This will reduce the size requirements for treatment areas and aid in keeping the compost area dry.
Composting facilities should be located on high ground to avoid flooding problems. Floodplains should be avoided. If facilities must be located in areas subject to flooding, they must be protected from a 25-year, 24-hour rainfall. Check with your local Soil and Water Conservation District or the Natural Resources Conservation Service to determine the rainfall corresponding to this storm level.
To protect ground water, the base of the composting facility should be on soil with a low permeability. The base of the compost site is also required to be a minimum of three feet above the high water table. These requirements help prevent water from leaching through the base of the composting facility into the ground water.
Composting will generate little if any odor, flies, or other nuisances when managed properly. However, when siting the composting facility, consideration must be given to the location of neighboring residences, production facilities, as well as public roads and highways.
Composting facilities should be located downwind of nearby residences to prevent any potential odors or dust from being carried to neighboring residences by prevailing winds. Aesthetics should also be considered; handling of dead swine may not be a welcome sight to nearby residents or passersby. Consider their viewshed, or area of sight, when siting the facility.
Control of pathogens and disease are critical to any swine operation. Traffic from the composting facilities to production housing should be minimized and if possible eliminated. The composting process successfully destroys diseases, but bacteria and viruses from fresh mortality can be passed through the transport vehicle to production housing. Collection of leachate should direct runoff away from production facilities.
Scavenging animals and vermin must also be kept from the compost. Maintaining the recommended cover over the compost pile will eliminate these problems. However, research has shown that once scavengers know there are carcasses in the pile, they will dig in the pile to find them. To avoid this always maintain the recommended cover on the compost. Fencing may have to be installed if scavenging animals are a problem.
Depending on the size and management of the swine facilities, swine may be added to the pile several times a week or every day. Ponding of water and mud will interfere with access to the composting area. To avoid these problems, construct a roadway that provides all-weather access to the compost area.
Loading and unloading of the compost facility must be possible in all weather conditions. Areas around the composting facilities that are used to unload finished compost must be firm and well drained. A solid base, such as gravel or concrete, is required in this area and will help prevent ponding water and accessibility problems from occurring around the compost facility.
Traffic flow to and from the compost area must be taken into account. Appropriate distances from overhead and underground utilities must be maintained to insure safety. The composting facility should be located and constructed so as not to interfere with other farm operations.
A checklist or inventory of requirements for the composting area produced by the Natural Resources Conservation Service is included on the following page. Refer to this checklist when comparing possible composting sites on your farm. Figure 1 shows a general layout for a composting site. Although all sites will be unique, this figure illustrates the general requirements for a composting site.
Siting the composting facility is an important step in meeting the objectives set forth for proper disposal of dead swine. Selecting a proper composting site will help protect water quality, prevent complaints and nuisance problems, maintain bio-security, and minimize the challenges in operating and managing the composting process.
|Site Selection Checklist for Dead Animal Composting Facilities|
Is the site
Does the location provide
Does the site have
Has the producer considered
|Figure 1. General site layout recommendations for composting facilities.|
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