Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/22/2004
Publication Date: 1/11/2005
Citation: Millner, P.D. 2005. Manure and organic residuals management issue: Balancing risks and benefits of different treatment technologies [Abstract]. Good Agricultural Practices Program. p. 87.
Technical Abstract: Epidemiological and public health records overwhelmingly support the benefit of treating water to eliminate fecal pathogens. Improved animal health and vigor as well as overall sanitation result when disinfection practices are incorporated into animal husbandry and other farm operations. In addition to animal manures and bedding, a variety of other organic residuals may contribute to the fecal microbe load brought to the farm. The nexus between animal and plant production for human consumption comprises a myriad of complex environments and matrices that have been shown to harbor fecal microbe contaminants. However, an expanding number of technologies are available by which to treat and thereby disinfect a wide variety of these feedstock materials, including landscape trimmings, wastewater treatment sludge, cafeteria residuals, nutrient rich slurries and cakes, and composts. The success of treatment relies on establishment and maintenance of process control criteria, adequate process monitoring, and failsafe procedures, along with periodic quality control and assurance. The means for implementing the process control type approach at commercial scales has proven successful in many places throughout the world; it is continually being refined. However, implementing some of these practices on-farm with manures represents some additional challenges and requires some trade-offs in order to ensure that the treated products achieve disinfection and are subsequently managed and handled in ways that avoid recontamination and thereby fecal contamination of foods. Several alternative management and handling techniques are available for farmers to use in place of intensive monitoring, testing, and high energy inputs. Options for using these techniques will be explained in the context of existing guidelines for pathogen destruction by typical aerobic/anaerobic, thermophilic digestion/composting. In weighing the risks and the benefits of implementing on-farm practices to reduce the potential for microbial pathogen contact and survival on food products, many factors must be taken into account. For example, not just one pathogen, but the most resilient ones need to be targeted in evaluation tests. Likewise, consideration must be given to the likelihood of elevated concentrations of pathogens among a range of sources, and a range of treatment technology efficacies and their costs. Decision analysis approaches that employ a probabilistic methodology for evaluating the effects of multiple dynamic variables could be useful in determining where in the treatment and production chain the greatest benefit can be achieved if treatment technologies are introduced. To some extent, despite the advances in residuals treatment technologies we must still confront the question: What effect does the potential for post-harvest contamination of produce have on the cost:benefit of disinfection of massive amounts of low value solids?