While six of a technology being investigated now do not meet environmental requirements, it may well be possible to alter some of them to do so.
One of the two systems granted conditional approval handles the full swine farm waste stream, while the other treatments only the solid portion.
An “on-farm isolation phosphorus removal system” processes the entire waste stream. It was created by Super Soil Solutions Inc and is often referred to as Super Soil.
The Super Soil method processes pig faeces in big metal containers resembling oil tanks. The Super Dirt system begins by removing the waste products that stays in the liquid after pig homes are flushed. The solids in the waste stream are removed using flocculating agents.
The residual liquid is tanked, where microbes eliminate nitrogen. Phosphorus is subsequently removed using chemicals as well as a “dewatering bag scheme” in a settling tank. Nitrogen are both important plant nutrients, but too much can harm the ecosystem.
Aside from the phosphorus removal procedure, solid manure can also be used as a fertiliser or soil amendment.
The remaining liquid is recycled into pig houses to flush waste, and 20% is utilised to water crop areas. Not a standard earthen lagoon required.
The second conditional technology is an off-farm total solids anaerobic digester. Organic Biomaterials LLC of Clinton & Arlington, Va., created the technology, known as ORBIT. Solid waste is treated in an anaerobic digester.
A shredder is a waste-degrading vessel. Two digesters are employed here. One resembles a truck trailer, the other a truck tank. Raising a digester’s temperature speeds up deterioration, lowering room requirements.
The digesters create sludge, which is screw pressed to separate both liquid and solid components. The liquid portion will be utilised to manufacture liquid fertiliser, and the solid portion as a soil supplement.
Among the other methods investigated in this part of the project are two belt designs that separate solid waste and urine. Solids separation is used to reduce odour because it is easier to carry solid manure than liquid waste. Moving garbage may make creating value-added goods from waste more possible.
An earthen digester which produces biogas to run a turbine and produce electricity for the farm was also examined, as was a closed tank waste treatment system. Phase I also included two solid separation systems with solids combustion to produce ash for fertiliser and a system that processes waste in stone basins. The gravel provides a surface for waste-degrading bacteria.
Several of these technologies could meet the ecological performance criteria with simple modifications. He added that it may be feasible to mix pieces or processes from different technologies to create systems that are more eco-friendly.
To be considered environmentally superior, innovations must be technically, operationally, and commercially feasible. Ammonia, airborne infections, odour and disease-transmitting vectors must be considerably reduced or eliminated from swine farms using environmentally better technologies.
Smithfield Foods will contribute $15 million, and the Attorney General will contribute $2.3 million from of the Premium Standards Farms agreement, totaling $17.3 million.
In 2002, the AG signed a third deal with Frontline Growers, a group of independent pig farmers. Frontline Farmers has committed to collaborate with the solicitor general at N.C. University in develop and deploy ecologically friendly technologies.
The systems being tested were chosen by panels comprised of government, swine industry, environmental groups, economists, and waste management professionals.
Initially, 18 technologies were chosen for examination. Three of a original 18 pulled out for various reasons. The remaining Five technologies are being evaluated. Phase I reports on eight of them.
Many technologies have been tested on full-scale hog farms. And most evaluations took a year or more. Once a system was operational, it was important to collect cold and warm season samples to assess its year-round performance.