Proper monitoring and maintenance of composting windrows is critical to the effective deactivation of HPAI in both the carcasses and the associated litter. This section covers:
Monitoring the temperature in the windrow to ensure effective inactivation
Turning the windrows to facilitate effective deactivation and composting
Other maintenance concerns
Disposal of compost after pathogens have been inactivated
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Use a 3-foot long digital temperature probe connected to a data logger to take daily temperature readings. With digital recording thermometers, the building only needs to be entered once a week thereby limiting exposure to the material.
Use a minimum of 2 probes per windrow based on
observed data variability
Initial measurements should be taken at fairly close increments to provide an initial idea of variability. If the observed temperatures are reasonably consistent (less than 10 degrees Fahrenheit difference between comparable locations), greater distances between monitoring locations would be justified. Occasional re-checks at the reduced spacing may be taken to verify that temperature variability hasn't changed greatly.
. Ideally, the probes will be placed at the
Sampling distance into the pile is as important as distance along the length of the pile. Windrow temperatures are often hotter near the core, or directly above the core beneath the crest of the pile. Lower temps are likely to occur near the sides of the pile. To ensure carcasses located near the edges of the pile are adequately heat treated, measure temperatures in the outer envelope of the pile .... not just deep in the core.
of the pile and inside the center of the pile, every 10 to 20 feet along the length of the pile.
Temperature measurements from windrows may be averaged. However, if temperature readings are consistently below 55° C (125° F), the windrow must be evaluated to determine how to maintain consistent temperature.
If the temperature exceeds 55° C (180° F), the pile must be treated to prevent fire hazard.
Composting Time Versus Temperature
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Temperature (C) (1)
Temperature (F) (1)
Duration (days) (2)
Insufficient microbial activity - rebuild pile to include appropriate moisture, air, and carbon source-to-mortality ration.
If pathogen is high path AI, omit 5 EPA-required turnings to protect worker health. (3)
Too hot for proper microbial activity - turn pile and/or aerate to reduce temperature to within optimum range.
Numerous sources cite the optimum temperature for compost microorganism activity to be in the range of 40-60Â° C (104-140Â° F).
According to EPA regulations concerning significant reduction of pathogens in sewage sludge by composting found in Title 40, US Code of Federal Regulations, Appendix B to Part 503Â—Pathogen Treatment ProcessesT: TÂ“Section B. Processes to Further Reduce Pathogens (PFRP), 1. TCompostingTÂ—Â…Using the windrow TcompostingT method, the temperature of the sewage sludge is maintained at 55Â° (131Â° F) or higher for 15 days or longer. During the period when the compost is maintained at 55Â° (131Â° F) or higher, there shall be a minimum of five turnings of the windrow.Â”
Research by the University of Delaware Extension Service found 10-14 days of composting without turning at a temperature up to 160Â° F (71Â° C) completely inactivated the avian influenza virus in windrows of composted mortalities.
Prior to relocating the pile outside, a minimum of 3 compost samples must be collected and analyzed to confirm inactivation of the AI virus
Scrape along the edges of the turned windrow and deposit material on the pile
Cap the turned pile with a minimum of 6 - 12 inches of carbon source to cover any exposed tissue on the surface
Turned windrows may remain in the poultry house until maturity or if testing has proved the AI virus is inactivated, moved outside. Windrows that remain inside the poultry house are not required to be
A cover protects the windrow against animal scavenging, wind/water erosion, etc.
Turning Windrows (2 of 2)
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Windrows that are moved outside the poultry house must be covered for protection.
Cover windrow with compost fleece or another suitable porous fabric to protect from scavengers. Use a cover that allows some air to circulate as this will cause condensation and may negatively affect the composting process.
Secure the material using dirt and soil on the edges or some other means to restrict scavengers from accessing the windrows.
Continue to monitor temperatures after turning.
Approximately 2 - 3 weeks after first turning, evaluate the windrow for maturity.
Disposal of Compost
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Two to three weeks after the first turning, the compost material may be removed. The following options are available for composted material:
Land applied and immediately incorporated in accordance with the nutrient management plan for the soil and crop or hay that will receive the compost
Landfilled as a nonhazardous waste
Stored and aged
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After turning the windrows, the pile should be capped with a minimum of how many inches of carbon source, in order to cover any exposed tissue on the surface?