A study of five compost feedstocks that have been proposed for use in composting animal carcasses was conducted in the fall of 2008. The purpose of the study was to compare the moisture retention and loss characteristics for the feedstocks by themselves when exposed to extreme rainfall events. It also included analyzing the leachate for a number of characteristics. The study is a prelude to a similar study that will collect data on leachate quantity and quality for one or more of the feedstocks when used to compost an animal carcass. An impervious collection platform was constructed to collect leachate generated by separate piles of various feedstocks, where each pile was exposed to 30 minutes of simulated rainfall (approximately 416 L total or the equivalent of a 25 year/24 hour rain event). Five compost feedstocks that may be used for animal carcass composting were tested: wood chips, a sawdust/shavings mix, leaf and yard waste, horse bedding, and immature sludge-derived compost. Three replicates of each feedstock (Trials 1-3) were constructed into small piles measuring 3 m 3 in volume. Each pile received simulated rainfall twice over a seven-day period (on Day 1 and again on Day 7). Piles were covered by moisture impervious materials between simulated rainfall events. Individual leachate samples (100 ml) were collected at regular intervals during the simulated rainfall periods and were analyzed for: micro nutrients; total phosphorus; nitrate-nitrogen; ammonia-nitrogen; total nitrogen; pH; and conductivity. Total leachate volumes varied widely between the various feedstocks tested. Wood chips averaged the most generated leachate (145 L), whereas the sawdust/shavings mix yielded the least leachate (40 L). Municipal sludge compost and horse bedding recorded the highest levels of nitrate-nitrogen in the collected leachate, whereas horse bedding and municipal leaf and yard waste leachate recorded the highest levels of total phosphorus. However, a review of nutrient uptake capacities of vegetation in a grassed filter area, demonstrate that none of the leachate collected during this study would exceed the ability of a vegetated filter area to utilize both nitrate-nitrogen and phosphorus.

No abstract

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government or any agency thereof, nor any of their employees, not any of its contractors, subcontractors nor their employees, makesany warranty, express or implied, or assumesany legal liability or responsibility for the accurarcy, completeness, or usefullness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacture, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opions of the authors expressed herein do not necessarily state or reflect those of the Unites States Government, Westinghouse Environmental ManagementCompanyof Ohio, WestinghouseElectricCompany, or any of its wholly owned subsidiaries,or any agency thereof.

A project measuring and comparing physical and chemical parameters within different zones of carcass compost piles built on two different surfaces was conducted in 2011. Physical and chemical parameters reflect processes within the carcass compost piles. Information gathered could be useful in improving carcass compost management systems. Previous work has revealed zones in carcass compost piles that are visually distinguishable (Rynk et al. 1992), however, only a few of these zones have had their physical and chemical characteristics analyzed. Data collected from three carcass compost piles on the soil and three on impervious platforms were analyzed for nutrients, bulk density, moisture, pH, conductivity, and metals. The carcass compost piles developed an identifiable structure with zones that could be distinguished based on color, texture, moisture and chemical composition. There was statistical significance between zones for all measured parameters except total carbon in all piles. This structure appears to help minimize nitrogen losses by intercepting both soluble N in fluids and gaseous ammonia and concentrating them in the organic material. Measurements in the bottom zone built on impervious surfaces only, revealed that water flowing under these piles was a significant mechanism for nutrient loss.