Abstract. Livestock production has become large-scale and institutionalized, creating environmental threats in the form of large and constant animal waste problems. This paper reports the performance of a new design of drum composter which uses 95% oxygen, intermittent tumbling and computer control to achieve a rapid and stable compost from livestock waste within 2-3 days. The composter which was designed by Environmental Products and Technologies Corporation was tested in southeastern Idaho and the Utah State University Dairy Farm near Logan, Utah. Performance was evaluated and stability determined by comparing beginning and ending C:N ratios, respiration rate, viable pathogens and weed seeds, and color and odor of final product.

THE PROBLEM

Many areas of the world have grown accustomed to a supply and demand matrix where clean water and other resources essential for life are available and commonplace. However, even before it is fully enjoyed by all the world's peoples, and even as new economies are just emerging, this matrix of plenty is in danger of collapse. Unfortunately, progress in many areas of economic endeavor has taken its toll on the environment, and no less so than in agriculture.

Animal livestock production has become large-scale and institutionalized, creating environmental threats in the form of large and constant animal waste problems.

In the United States, often looked upon as the most sophisticated of the world's agricultural economies, methods of dealing with animal waste are little beyond the outhouse stage. If the United States is to remain an important agricultural force, and if other countries are to follow our example toward the establishment of sustained agricultural force, and if other countries are to follow our example toward the establishment of sustained agricultural economies, then we must find a means of solving our monumental waste problem. Currently, in the United States alone, dairy farming is responsible for the production of more than 130 times more animal waste (effluent) than human waste, representing five tons for each and every person in the United States.

In the state of California alone, the region's 1,600 dairies produce more waste than a city of 21 million people. Add to that the waste generated by large-scale food production, including meat, vegetables, grain and processed foods -- and we are literally burying ourselves with waste.

The obvious question is where does all this waste go? According to traditional practices, dairies and animal feeding operations use large drainage ditches or lagoons for disposal of livestock effluent. These lagoons are typically dug adjacent to animal confinement buildings, and lined with clay and/or vinyl material to increase their containment life span to as long as 15 years.

Waste lagoons can cover several acres and can be 20 to 30 feet deep. Improper construction is commonplace. Additionally, 15 years is a relatively short time in the life of a successful animal raising or food production operation. Susceptible from damage from the elements, often the lagoons are structurally compromised. In many instances this has allowed the waste within to flow easily across fields into public waterways, seep into aquifers and threaten drinking water supplies and deposit unwanted and potentially harmful hormones, pathogens, nitrates, ammonia, phosphorus, and deadly coliform bacteria.

The animal waste resultant of industrialized farming can be avoided -- and even exploited for energy production -- with a proven, cost-effective solution that is ready for the market now.

THE SOLUTION

Environmental Products & Technologies Corporation (EPTC) was founded upon the belief that, with proper methods, the environment can be cost-effectively renewed, and that to do so represents not only sound stewardship but also a solid profit opportunity. In step with this revelation, EPTC committed vast amounts of human and capital resources toward the research, development and design of a cost-effective solution to the waste problems associated with the world's food production.

EPTC's market-ready drum composter, called an Aerobic Bioreactor, with advanced features such as computer-controlled mixing and feeding, automated loading and unloading, and aeration with 95% oxygen, represents an evolution in composting technology.

Once unusable, animal and vegetable waste can be converted into mature compost in minimal amounts of time, in quantities large enough to provide a viable resource as a soil amendment, soil conditioner, or as a feedstock for energy production, benefitting both the land and the bottom-line of animal feeding and food production operations.

INDEED, IT WORKS

A test run of EPTC's Aerobic Bioreactor activated in the fall of 1998 demonstrated that a stable compost could be produced from animal manure and straw bedding material in a period of 48 to 72 hours. Similar tests on vegetable matter are currently being conducted, and preliminary results also indicate a strong opportunity for commercial viability.

Waste is first collected as close to point-source as possible and then routed to a machine whose sole purpose is to pre-prep the waste stream (i.e. separator, grinder, chopper, etc.) so that a consistent material is generated (approximately 50% to 60% moisture content), prior to being fed into the Aerobic Bioreactor. Once loaded, the material undergoes a compost maturation process, while it tumbles in the Aerobic Bioreactor drum. The rotation sequence of the drum is totally automated and handled by the on-board electronics, which can be checked or changed via a remote communications link. While the compost process inside the drum is the same as in other methods, the computer-controlled environment provided by the Aerobic Bioreactor accelerates the production and increases the overall quality and controlled consistency of the byproduct.

The Aerobic Bioreactor utilizes a combination of both computer-based process controls and sensory technology, to both control and acquire data. The system provides a cost-effective, efficient way for both remote control and monitoring the Aerobic Bioreactor. The gases produced (primarily carbon-dioxide) are treated for odor prior to their release.

Completed compost is emptied and the opposite end of the drum into an auger, which deposits it far enough away from the Bioreactor to allow pick-up by a front-end loader. While an ammonia odor is present at the time of output, this odor dissipates after 48 hours of finishing on a concrete slab, leaving a faintly musty or earthy odor typical of traditional, commercially prepared composts.

The finished compost may be used as a nutrient-rich soil amendment wherever needed and has been shown to have a near-term positive effect relative to growth, color and vitality on plants to which it has been applied.

An on-site Aerobic Bioreactor (6-feet in diameter and 18-feet long), is insulated to help retain a high proportion of the heat produced. Its relatively small footprint makes it practical even for smaller agricultural operations requiring judicious and productive use of all available land.

RESULTS THAT SPEAK FOR THEMSELVES

Analysis of the compost showed significant amounts of nutrients and micro nutrients that are essential to crops. No harmful or hazardous products were produced during the compost process. The condensate produced during the process contained nothing considered hazardous to crops.

Not surprisingly, no pathogens were found in the compost because the contents of the well-insulated Aerobic Bioreactor were maintained at 140 degrees. Windrow or stack composting, which also results in a significant amount of dust, often had cold spots that decelerate decomposition. In contrast, the EPTC Aerobic Bioreactor with its contained process is highly effective in killing all known pathogens in a short amount of time.

THE RECLAIMED COMPOST

The color of the finished product is a dark blackish-brown, and is comparable to compost matured with processes that require significantly more time. Finished compost has an earth smell, similar to other commercially-available mature composts. No viable weed seeds were found in the compost from any laboratory tests.

As man as a species exploits the earth's resources, we must be conscious of giving back that which we take. And, while we are inarguably the most exploitative of all the earth's creatures, we also have the intelligence to engage in the sort of responsible stewardship that can actually help perpetuate the earth's riches.

As a soil amendment or soil conditioner, reclaimed compost has the ability to replace part of the billions of tons of top soil lost yearly to erosion and to reinvigorate weak soils with vital nutrients for crop production.

Additional innovative uses of compost include its use as an agent in bioremediation and pollution prevention, disease control for plants and animals, reforestation, wetlands restoration, habitat revitalization, erosion control, turf remediation and landscaping. Additionally, on-site treatment of agricultural and vegetable waste obviates the danger of spillage over transport routes, a highly problematic source of secondary pollution.

And, while one small farm may not consider it cost-effective to treat its own waste, the system's scalability and portability easily lends itself to a cooperative approach, whereby mobile units could be used on-site at various locations to treat waste accumulation periodically.

If we are to thrive in the 21st century, we must establish cost-effective solutions to the waste problem, rather than relocations and postponements. By eliminating the major pollution problems resulting from the operation of large-scale agriculture and food production activities, the EPTC Aerobic Bioreactor is a major piece in the puzzle we call sustainable development. Not only in the United States, but also in every country of the world where more efficient, lower impact agricultural and food production have become major issues, the EPTC Aerobic Bioreactor represents a major contribution to sustainable development.