Animal and Poultry Waste Management Center, College of Agriculture and Life Sciences
Development of Environmentally Superior Technologies for Swine Waste Management per Agreements Between the Attorney General of North Carolina, Smithfield Foods, Premium Standard Farms, and Frontline Farmers

link to North Carolina State University home page

3rd Generation Terra Blue (Super Soils) Technology Report

Second Generation Super Soils Technology Report

Phase 3 Technology Determinations Report

Phase 2 Technology Determinations Report

Phase 1 Technology Determinations Report

link to Technology Descriptions

link to Text of the Agreement (PDF)

link to A Few Words About Waste

The Agreement

In the summer and fall of 2000, the Attorney General of North Carolina entered into agreements first with Smithfield Foods and its subsidiaries and then with Premium Standard Farms under which the two companies consented to fund development of environmentally superior waste management technologies for use on North Carolina swine farms owned by the companies.

Smithfield Foods agreed to provide $15 million for this effort, while the attorney general allocated $2.1 million from the Premium Standard Farms agreement, for a total of $17.1 million for the environmentally superior technologies identification and development initiative. In March of 2002 the attorney general entered a third agreement with Frontline Farmers, an organization made up of independent swine farmers. While Frontline Farmers is not providing funding, the organization's membership did agree to work cooperatively with the attorney general and North Carolina State University to develop and implement environmentally superior technologies.

The various agreements call for a "designee" to oversee the selection and evaluation of technologies. C.M. (Mike) Williams, director of the Animal and Poultry Waste Management Center at North Carolina State University, was appointed designee by NC State Chancellor Marye Anne Fox.

The agreements define an environmentally superior technology as "any technology, or combination of technologies that (1) is permittable by the appropriate governmental authority; (2) is determined to be technically, operationally and economically feasible for an identified category or categories of farms as described in the agreements and (3) meets the following performance standards: 1. Eliminates the discharge of animal waste to surface waters and groundwater through direct discharge, seepage or runoff; 2. Substantially eliminates atmospheric emissions of ammonia; 3. Substantially eliminates the emission of odor that is detectable beyond the boundaries of the parcel or tract of land on which the swine farm is located; 4. Substantially eliminates the release of disease-transmitting vectors and airborne pathogens; and 5. Substantially eliminates nutrient and heavy metal contamination of soil and groundwater."

Selection of environmentally superior technology candidates to undergo performance verification and economic analysis involved a request for proposals that was issued nationwide to research institutions and industry. Technology selections were based on terms and conditions of the agreements and competitive review (outside ad hoc review) as well as review by an Advisory Panel appointed by the designee (per the Agreements) and comprised of individuals representing government, environmental and community interests, the companies (Smithfield, Premium Standard Farms and Frontline Farmers) and individuals with expertise in animal waste management, environmental science and public health, economics and business management. This process yielded 18 technology candidates. These technologies are now is various stages of construction or operation and performance verification. For a brief description of each technology, please click the technology.

Candidate Technologies

Phase 1 technologies

Phase 2 technologies


A Few Words About Managing Waste

The vast majority of North Carolina hog farms use what has become known as the lagoon and spray field system to manage the wastes from their animals. Pigs are raised in houses with slatted floors. Manure drops through the slats to a pit beneath the house. Periodically, the manure is flushed from houses to a lagoon, a large earthen basin, where microbes decompose the waste.

Most lagoons are open, so they tend over time to fill with liquid, particularly during unusually wet weather. In order to keep the liquid in the lagoon at a manageable level, farmers spray the liquid on nearby fields, where crops or grass can use the nutrients in the waste. Well-managed lagoons have been shown to be an effective and economical method of treating waste, while spraying the excess liquid on nearby fields makes use of the nutrients in the waste.

But the lagoon-spray field system can have drawbacks. If not managed properly, lagoons can be a source of odor, while lagoons have broken and spilled their contents into nearby surface waters. And the area to which lagoon liquid may be applied is limited by the distance the liquid can be moved.

The agreement between the North Carolina Attorney General and Smithfield Foods, Premium Standard Farms and Frontline Farmers provides a method of evaluating waste management technologies that hold promise as alternatives to the lagoon-sprayfield system. The agreement provides funding to build alternative technologies and to evaluate those technologies. Researchers from North Carolina State University are doing the evaluations.

On the pages of this Web site, readers will find descriptions of the various candidate technologies as well as reports on evaluations of the technologies. Several terms turn up repeatedly in these descriptions and reports.

Many of the candidate technologies, for example, include a process called solids separation. Lagoon and spray field waste treatment technology not only mixes solid and liquid wastes but dilutes the waste with water. That's an efficient way to deal with the waste if you don't want to move it very far. However, the weight and volume of the diluted waste makes movement difficult and costly. And being able to move waste is often necessary if the waste is to be processed to produce value-added products. That's why systems that separate the solid and liquid portions of the waste stream are part of many of the technologies being evaluated. The solid portion of the waste stream particularly is a candidate for processing to produce value-added products.

Separating the solid and liquid portions of the waste stream may also help deal with odor and ammonia emission problems. Both odor and ammonia are produced by the action of fecal microbes on the manure constituents. If urine and solid waste are separated, and the feces dried, odor and ammonia emissions should be reduced dramatically.

Swine waste, like other types of waste, contains the nutrients nitrogen and phosphorus. Nitrogen and phosphorus are essential building blocks for plant and animal growth, but in excessive amounts both can be problematic, particularly in surface or groundwater.

As a result, many of the candidate technologies are designed to deal with nitrogen and/or phosphorus. Nitrogen can be particularly tricky to deal with because it occurs in a number of different forms. Indeed, nitrogen is the predominant gas in the atmosphere, making up 79 percent of the air we breathe. Ammonia is also a form of nitrogen.

Readers will see numerous references in these reports and descriptions of processes called nitrification and denitrification. Nitrification is the process of converting ammonia to nitrate, another form of nitrogen. Bacteria, or microbes, turn ammonia into nitrate, and they do so in an aerobic, or oxygen-rich, environment. That's why a number of candidate technologies involve aeration, which creates the aerobic environment needed for nitrification. Denitrification, on the other hand, is the conversion of nitrate to nitrogen gas, the harmless form of nitrogen that makes up most of our atmosphere. Denitrification is an anaerobic process. It takes place in an oxygen-less environment. Indeed, many of the candidate technologies involve processes designed to create anoxic conditions, which occur when nitrate is present in an oxygen-free environment.

The swine industry is an important part of North Carolina's economy. The alternative waste management technologies being evaluated are designed not only to treat waste in a manner that protects the environment but also to treat waste in an economically feasible manner that allows the swine industry to survive. We hope the information on this Web site helps explain this important effort to develop alternative waste management technologies for North Carolina's swine industry.