Butcher Waste Composting for Field Fertility

SUMMARY

Following closure of southern Oregon’s only two rendering facilities, our local custom processing plant faced limited options for disposal of butcher waste. Our ranch has acres of deficient soil and the space necessary to host a composting site. This project made it possible to take waste and turn it into a valuable product.

We successfully composted the waste from approximately 500 beef, 400 hogs and 150 lambs. Although it requires extra effort on our part compared to the traditional rendering arrangement, it provided benefits to both operations. Composting has become and will remain an integral and sustainable piece in our ranching and meat processing businesses.

In the beginning, we had some regulatory hurdles to overcome but have since forged alliances and a cooperative process that will benefit other producers, both in agricultural and meat processing enterprises.

OBJECTIVES

1. Solve existing solid waste disposal issues.
2. Create a valuable final product.
3. Enhance deficient soils.

RESULTS

Because our feedstock (butcher waste and wood waste) came to the ranch from outside sources, it was considered a commercial composting operation and had to meet all the requirements of such as defined by the Department of Environmental Quality. The Oregon Department of Agriculture wrote the composting plan, provided site visitations and paid a portion of the original permit fees.

We began the composting project with a static windrow approximately 100 feet long by 12 feet wide. The windrows are constructed with a base layer of wood chips 12 inches deep (allows for airflow under and through the windrow), a 6 inch layer of wood sawdust (provides absorption), and butcher waste 3-5 feet deep. This is then covered by a protective cap of 18-24 inches of additional sawdust.

We found that only the newly introduced butcher waste needed protection. After 5-7 days of active composting, the windrows no longer appeal to coyotes, eagles, domestic dogs and skunks. Only a small 30- by 40-foot tarp is required.

Effective composting requires four elements in correct proportions: carbon (wood chips), nitrogen (butcher waste), oxygen and moisture. We found that 3-5 days after introducing new feedstock, we could attain the required temperature of 130°-160°F and maintained it for 7-10 days.

The static windrow limited airflow and caused the oxygen requirement to be out of balance. To implement aeration, we used perforated 3-inch aluminum irrigation and 4-inch black poly drain pipe and placed them in the base layer of wood chips in the direction of the prevailing wind. However, the poly pipe was too delicate and crushed easily. The aluminum pipe could be reused over and over, so we opted to use that in the future. With the addition of aeration, the rise in temperatures occurred sooner and lasted longer.

Once the inherent moisture in the feedstock depleted, the process slowed or stopped. We implemented 12 hours of water in a 1 hour on/1 hour off sequence using an 8 gph sprinkler emitter with a 12-12 foot pattern set on 8 foot spacing. This provided adequate water without runoff.

Because of the slow nature of a static aerated system and the need to reuse the materials (a minimum of three times) only one windrow out of five built and reused was ready to be screened and applied. Initial testing has shown that we have achieved a full coliform pathogen reduction.

BENEFITS OR IMPACTS ON AGRICULTURE

We know our operation traded the expense of a traditional rendering arrangement, approximately $6,000/year, for the more labor-intensive method of composting that does not have the direct or obvious associated costs. If that trade were deemed comparable then we still have the valuable end-product that will increase the production levels of the deficient soils they are applied to, providing yields that may not be easily measured.

Beyond the economic benefits, we feel the satisfaction of knowing that we have created a system that leaves a positive footprint. Our community benefits from the removal of wastes that would potentially clog our landfill and create water-quality issues.

REACTIONS FROM PRODUCERS

Whenever the project is discussed at a local recycling meeting, the annual convention of the meat processors association, or with local high school students, the reaction is positive and people are amazed by the simplicity and potential of this project.

RECOMMENDATIONS OR NEW HYPOTHESES

We learned the following key points:
1. Orient windrows aerated with perforated 3-inch aluminum pipe lengthwise with the prevailing wind.
2. Mix carbon and nitrogen products to ensure adequate contact.
3. Provide moisture to 50-60% of the material.
4. Screen before applying and reuse material too large to apply.
5. Be patient – it’s a slow process.

OUTREACH

We published articles in the Goose and Summer Lakes Basin newsletter, the Capital Press agricultural website, and in the Lake County Examiner newspaper.