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Introduction
Over the past two decades, agricultural economics have changed resulting in changes to farming practices and the trend toward larger herd sizes. At the same time, development has decreased the amount of land available for grazing and growing feed crops and has impacted the location and manner in which farmers can spread manure. These changes have led to greater confinement of animals as farmers try to improve animal nutrition and contain and collect manure.

As livestock production methods change, environmental management practices must change as well if we are to protect our valuable land and water resources. The U.S. Environmental Protection Agency (EPA) has issued new regulations for Concentrated Animal Feeding Operations or CAFOs as part of continuing enforcement of the Clean Water Act. By 2007, these regulations will require large agricultural operations to create and follow a plan to improve their water quality, odor emissions and greenhouse gases as part of the permit process. The Wisconsin Department of Natural Resources (WDNR) will enforce these regulations through a revision in NR 243, the existing state CAFO rules.

This article will focus on a new technology being developed by Skill Associates, Inc. that consists of a manure management process that essentially eliminates the need to spread manure and also generates green energy.

The Issues
Manure management is a critical issue on all farms for on-site management as well as during disposal. While nutrients like phosphorus and nitrogen are valuable components of manure, and essential for crop growth and animal production, improper management of manure can lead to eutrophication of rivers, lakes and estuaries. Eutrophication is the accelerated �aging� of waters caused by excessive nutrient loading which causes excessive plant growth, fish kills and reduced aesthetic quality. Manure may also contain bacteria and chemicals that can affect the health of humans if they enter surface and ground water. Preventing manure runoff during rain storms is particularly critical for CAFOs given the amount of manure these large farms generate. Since one cow produces as much waste as eighteen people, a single CAFO has as much pollution potential from untreated waste as the cities of Sun Prairie, Wisconsin Rapids, Onalaska or Ashwaubenon. Increasing development pressure and the resulting loss of available land for spreading liquid and solid manure could make it difficult for large farms to comply with these rules.

New Regulations
The WDNR website lists specific changes to NR 243 that, if approved, would:

• Prohibit applying liquid manure on frozen or snow-covered ground unless it�s injected or immediately incorporated into the soil and prohibit spreading solid manure on frozen or snow-covered ground during February and March unless it�s immediately incorporated.

• Require six months of liquid manure storage.

• Require that manure spread on land be set back from private and public drinking water wells and from sinkholes and fractured bedrock. Additional restrictions would apply to manure and process wastewater spread on areas with shallow soils.

• Require farms to implement nutrient management plans based on applying the right amount of phosphorus.

• Require farms applying manure near lakes and streams to implement practices such as leaving crop residue on fields to protect against manure runoff.

• Require farms to develop an emergency response plan to address manure spills or discharges.

New Technology
Meeting these requirements will require a variety of options to address the volume of manure produced on large farms. The actual nutrient content of the manure, local slope and soil conditions as well as surrounding water quality issues will also affect how farmers can address these issues. The �Elimanure� System� located on the Weise Brothers farm near Greenleaf, Wisconsin is a new system and the only model in the world that uses technology similar to that used in the paper industry to dry manure and then burn the product to produce electricity. This system is different than a digester which uses an anaerobic process to produce methane and dried solids as well as a liquid that still must be hauled and land spread. It uses hot air to dry the manure reducing its moisture content to 40% and in the process, effectively sterilizing the manure. The end-product can be used for bedding or sent by conveyor to a bio-mass burner that uses thermal gasification to create steam. Thermal gasification is the burning of materials in the presence of a limited amount of air or oxygen, producing a combustible gas. This gas is then burned to run a boiler that produces steam. The steam is piped to a turbine that generates electricity that can be used internally in the operation and can be sold to the local power company. The excess steam can be used to heat water, heat the operation, and with the use of a heat exchanger, heat the air that is used to dry the manure. The water from the condensing stream is recaptured and sent back into the system. The entire process uses only 8 gallons of fresh water per day. Other than some added sawdust and electricity at startup, the system is fully self-supporting.

The Weise farm milks 1,500 cows and totals over 3,000 animals in all. They own 3,000 acres and in the past hauled 4,500 tank trucks of liquid manure annually. Each truck contained 7,200 gallons of manure which resulted in approximately 623,077 gallons of manure per week being hauled on local roads and spread on nearby fields. On site are three manure lagoons each holding six months of liquid manure. By installing the new technology, manure will be reduced to an ash by-product that will fill a small 9� x 5� x 5� wagon 50 times a year � about once every 8 days. The farm has a contract to sell all the ash to a seed producer who will use the ash to coat seeds thus eliminating all land spreading of manure from the farm.

The dry manure produced in the first part of the process will be used as sterile bedding eliminating a significant operational cost. The remainder will be used to produce electricity to run the operation. Any excess energy, enough estimated to run 600 homes annually, will be returned to the grid. Savings will also be gained by producing their own heat and the hot air needed to dry the manure. Another important by-product of the system is the elimination of odor from all parts of the farm operation.

This system comes with a large price tag � approximately $4 million. Because the technology uses standard equipment from other industries and produces an income as well as a savings in farm expenses, banks have indicated that they would be willing to offer construction loans for the process. Money is also available through federal programs. The Weise farm expects a return on investment in 2.6 years.

Implications For the Future
This process is still undergoing EPA testing but preliminary numbers indicate that the minimum size farm needed for profitability would be 1,000 cows with a milking herd of at least 500. The process has an upper threshold of about 3,000 cows, after which an additional burner and turbine may be needed to process all of the manure produced. Manure can be pumped up to a mile to reach the system. It is conceivable that several nearby farms could join together to support such a system making it cost-effective for smaller farms to take advantage of the technology. This system would work for all types of animal waste and has the potential to process municipal sludge as well. Partnerships between small rural communities and surrounding farmers could create win-win solutions for everyone. While some crops may still need fertilizer, the system can eliminate the need to spread manure in areas where, due to soil type, slope, ground water and surface water issues, it is inadvisable to do so.

Critical to the expansion of this technology will be the adoption of local ordinances and regulations that allow its use. Farms wanting to expand and use this technology will need to be allowed to reach size thresholds that maximize the technology. This system can play an important part in the suite of new technology that will be required to produce the food supply we need while protecting our land and water resources.

The statistics found in this article and other NR 243 information can be found on the WDNR website.

Additional information about the Elimanure� System can be found at
www.burnmanure.com.