Perspectives Online

End of an Era. More than five years of work to identify alternative waste management technologies culminate in some 'environmentally superior' solutions. By Dave Caldwell.


In 1999, Dr. Mike Williams (above) looked ahead to his work as director of the College's Animal and Poultry Waste Management Center, where he led the Smithfield initiative to identify new waste management technologies.
Photo by Herman Lankford

Call it the Smithfield Era, a span of time defined by efforts in the College of Agriculture and Life Sciences to identify alternative waste management technologies for North Carolina's swine industry.

It lasted more than five years. It is difficult to pinpoint exactly when the Smithfield Era ended, but March 8, 2006, is probably as good a date as any. That's the day Dr. Mike Williams reported to the North Carolina Environmental Review Commission that the Smithfield initiative had singled out a combination of technologies considered "environmentally superior" to the lagoons and spray fields now used on most North Carolina swine farms.

As director of the College's Animal and Poultry Waste Management Center, Williams led the effort to identify alternative waste management technologies. But when Williams addressed the Environmental Review Commission he did not do so as Waste Management Center director. He had already left that position to serve as undergraduate teaching coordinator in the Department of Poultry Science.

Dr. Winston Hagler, assistant director of the North Carolina Agricultural Research Service, is serving as interim director of the Animal and Poultry Waste Management Center.

With one notable exception, Hagler said the Waste Management Center will continue to operate as it has in the past, funding waste management research projects. That exception is the role the center played in what was widely known as the Smithfield Agreement.

In the summer and fall of 2000, the North Carolina Attorney General's office entered into agreements first with Smithfield Foods, the world's largest pork producer, then with Premium Standard Farms, under which the two companies agreed to fund an initiative to identify waste management technologies considered, in the words of the agreements, "environmentally superior" to the lagoon-spray-field system. Williams was selected to lead the effort. Since then, experts from the College of Agriculture and Life Sciences and elsewhere have been developing and evaluating alternative swine waste management technologies.

In a report dated March 8, Williams identified a combination of waste management technologies that he decided meet environmental and economic feasibility criteria for new and expanding hog farm categories as spelled out in the Smithfield Agreement.

One of the technologies identified treats the liquid portion of the waste stream from a hog farm. Williams also identified four technologies that treat the solid portion of the waste stream. He said in the report that the liquid treatment technology may be combined with any of the solid treatment technologies to create an environmentally superior swine waste treatment system.

While the Smithfield agreement spells out environmental criteria technologies must meet, it also stipulates technologies must be economically feasible. In reports issued over the last two years, Williams found that five technologies met environmental criteria to be considered superior to the lagoon and spray field system. When those earlier reports were issued, however, an economic assessment had not been completed.

The economic assessment has now been completed, although there was disagreement among members of an advisory panel appointed by Williams as to what constitutes economic feasibility. The disagreement centered on the effect adoption of a waste management technology is likely to have on North Carolina's swine herd. Some members of the advisory group felt a technology should be considered economically feasible only if its adoption would have no effect on the number of pigs in the state. Others felt a technology could be considered economically feasible even if its adoption caused a reduction in the size of North Carolina's swine herd. Williams' report contains majority and minority reports stating each view.

Williams decided that a technology may be considered economically feasible even if it costs more than a lagoon and spray field system and if adopting the new technology would cause North Carolina's swine herd to shrink by as much as 12 percent.

The liquid treatment technology Williams approved was developed by Super Soil Systems USA. The solid and liquid portions of the waste stream are separated, then the liquid portion is treated in a series of large metal tanks. A composting system developed by Super Soil Systems was among the technologies approved for solid waste treatment. Waste is mixed with bulking materials such as cotton gin residue or wood chips, while a machine called a Compost-A-Matic is then used to mix the material daily.

Two other technologies approved for solid waste treatment treat waste by burning it.

One of these two technologies burns waste in a chamber called a gasifier. Gasification involves burning a substance in a low-oxygen environment, which converts complex organic compounds in the substance to gases. It is possible to collect gases such as methane, carbon monoxide and hydrogen and make ethanol.

The second burning technology goes by the acronym BEST, for Biomass Energy Sustainable Technology, and includes two methods of separating the solid and liquid portions of the waste stream. Solids are then burned in a fluidized bed combustion system. In this system, the temperature is above 1,300 degrees F. Both combustion systems produce ash, which contains nutrients and has value as a fertilizer.

The fourth technology is a high solids anaerobic digester known as ORBIT. The centerpiece of this system is an enclosed anaerobic digester, a large metal container. Waste is placed in the digester, where microbial activity converts it to biogas (methane and carbon dioxide).

Smithfield Foods provided $15 million to evaluate technologies, while the attorney general allocated $2.3 million from the Premium Standard Farms agreement, for a total of $17.3 million. In 2002 the attorney general entered a third agreement with Frontline Farmers, an organization made up swine farmers. While Frontline Farmers did not provide funding, the organization's membership agreed to work with the attorney general and North Carolina State University to develop and implement environmentally superior technologies.

According to the agreements, technologies must be technically, operationally and economically feasible and eliminate the discharge of animal waste to surface or groundwater in order to be designated environmentally superior. Environmentally superior technologies must also substantially eliminate the release from swine farms of ammonia, odor and disease-transmitting vectors and airborne pathogens and eliminate contamination of soil or groundwater with nutrients or heavy metals.

Seventeen technologies were evaluated. In most cases, technologies were built full-scale on hog farms, then evaluated. Williams said several technologies were close to meeting the environmental criteria to be considered environmentally superior and might be able to do so with relatively minor adjustments.

In his report, Williams suggested that technology suppliers and researchers continue efforts to bring the cost of treatment systems down to the point it would be economically feasible to retrofit existing hog farms and that a process be developed to evaluate additional technologies.

Williams also suggested that efforts be made to "identify potential institutional incentives, public policies, and markets related to the sale of byproducts (with priority on energy production) that will reward farmers for utilizing technologies . that are shown to yield improvements and environmental benefits over the current lagoon spray field system."

He added, "The optimal method of achieving net cost reductions and even positive revenue flows from alternative technologies is to install targeted technologies on a sufficient number of farms to facilitate engineering improvements, value-added product market development, and other cost reduction methods."

Williams said the evaluation effort funded under the Smithfield Agreement is finished. With the end of Smithfield work, Hagler said College waste management programs have entered a period of transition.

"The end of the Smithfield era will allow us to refocus and plan for the future in waste management," Hagler said.

The Animal and Poultry Waste Management Center will continue to fund waste management research. Hagler said the Center's Waste Processing Facility at the Lake Wheeler Road Field Laboratory continues to be particularly busy.

He added that much of the College's waste management work may now focus on refining and developing some of the technologies evaluated under the Smithfield Agreement.