A research project at North Carolina State University (NCSU), studying 15 alternative manure management technologies, has identified two as having potential to be “environmentally superior.”

The two technologies projected as better than the current swine lagoon and sprayfield system commonly used in North Carolina are a long way from reality, however, and may be too costly to implement anyway.

Mike Williams, director of the Animal and Poultry Waste Management Center at NCSU, indicated at a July 26 press conference that the two systems had cleared a major hurdle toward being declared “environmentally superior.” The two systems reduce nitrogen, ammonia, odor and other pathogens to acceptable levels.

Williams directs the four-year-old, $17.3 million effort between the state of North Carolina and pork industry partners to identify and quantify alternative swine waste management technologies. Large swine integrators Smithfield Foods and Premium Standard Farms, under agreements the two parties reached with the North Carolina attorney general in 2000, fund the study.

Questions Remain

“The two technologies identified met one of the conditions of the agreement, and that is they appear to meet the environmental performance criteria,” says Rann Carpenter, chief executive officer, North Carolina Pork Council. “But Williams also pointed out, and I think very appropriately, that the other equally important components, the operational and economic feasibility issues, have yet to be determined,” adds Carpenter.

“Williams has done an excellent job of managing a challenging process, and they continue to support his work,” states Don Butler, director of governmental relations and public affairs at Murphy-Brown of Warsaw, NC, the livestock production subsidiary of Smithfield Foods.

The project has faced many roadblocks, including delays in obtaining permits, finalizing construction contracts, completing construction and actual technology evaluations. Some of the most important questions in this process remain unanswered, he notes.

Those questions include determining which farms the technologies may work on, whether a typical farmer could operate them and whether they are operationally and economically feasible.

Williams stressed the agreement stipulates that the projects must prove economically viable before they can move forward.

Two Technologies Outlined

Leonard Bull, associate director of the NCSU waste management center, says the first technology is called ORBIT (Organic Biotechnologies, LLC). It features a high-solids anaerobic digester being tested at Timber Ridge Farms near Clinton, NC. The enclosed digester will be used to convert solid hog wastes into biogas (methane and carbon dioxide). The biogas can then be used as an alternative energy source to generate electricity or heat. The liquid portion will be used to make a value-added liquid fertilizer.

The second technology, known as Super Soils (Super Soil Systems USA), could provide the swine waste solids for a digester such as the ORBIT example. Alternatively, solids could be composted and blended to produce a value-added product to be bagged and sold off the farm. The liquid portion of the swine manure is processed through a series of large metal tanks to remove nitrogen and phosphorus and retain calcium phosphate, which has value as fertilizer. Eighty percent of the liquid is recycled through hog barns, and 20% is applied via irrigation to cropland.

Bull expects that the evaluation results of 4-5 more technologies will be rolled out by the end of this year, with the rest of the project evaluations completed within another year. It is also possible that several technologies could be utilized in combination.

More information on the Smithfield/PSF agreement and project results are posted at: www.cals.ncsu.edu/waste_mgt/.

Lagoons' Legacy

“An anaerobic treatment lagoon that is properly designed, constructed and managed, combined with land application of treated effluent as organic crop fertilizer, is a very good system,” says Butler. “Sound management will be the key to environmental protection, regardless of the type of technology employed by the industry in the future.”

The state's approximately 4,500 active hog lagoons have weathered a series of strong storms and hurricanes in the last decade, says Carpenter. Even during Hurricane Floyd, which battered North Carolina's coastline in 1999, 98% of the state's hog lagoons were completely untouched by floodwaters. Fifty lagoons were impacted by floodwaters and only six were breached.

The secret to the success of any swine waste management system is a high level of management, regardless of the type of technology utilized, and that's what North Carolina's pork producers are demonstrating, observes Butler.

Having said that, state pork producer leaders still support Williams' work.

“We do believe strongly that Dr. Williams should be allowed to complete his work and make the environmental and economic determinations, so that people will have factual information by which judgments can be made on appropriate waste management technologies for any given hog farm,” states Carpenter.