(PROBLEM DESCRIPTION
AND OUTLINE OF PROPOSED WORK)
Background
North Carolina is on of the top producers in the swine industry in the United States. It is thus imperative that management techniques for the treatment of waste resulting from farming operations are kept updated and improved upon. Waste from animal farms may pose a serious environmental, human health, and aesthetic problem if the proper waste management techniques are not employed.
Hog farming waste is currently managed predominantly through anaerobic lagoons and sprayfields. Despite the fact that this technology meets current state and federal standards, studies indicate that such anaerobic lagoons, as much as sprayfields leak nitrogen and other pollutants into ground and surface water (1).
In 1998, the state of North Carolina has proposed a phasing-out of anaerobic lagoons and their replacement with alternate technologies in an effort to avoid ill public health and further negative environmental impact.
The Animal and Poultry Waste Management Center of North Carolina State University is currently identifying and evaluating existing treatment technologies, thus providing information that is essential for achieving swine waste management improvements (2).
Researchers in the College of Agricultural and Life Sciences at NCSU are gathering this information and using it in an empirically-based simulation model that returns predicted nitrogen, phosphorus, and total suspended solids (TSS) reduction parameters, for any size hog farms that use specific treatment technologies. The model also returns a qualitative estimate of the amount of ammonia volatilization as well as quantifies the capital, expected annual cost, and cost per pig place associated with each technology.
Management
Issues Facing North Carolina
The outcome of the ongoing technology evaluation study needs to be effectively used in identifying appropriate future directives for new animal waste management strategies. To achieve this, multiple farms will be examined simultaneously, as sources, when at the same time multiple goals, such as N, P, TSS, and possibly qualitative parameters such as odor, and NH3 volatilization, need to be examined and analyzed. Such a framework should be able to assist in making decisions such as determining which farms should adopt which technology so that the public and private costs are minimized while maximizing their net effectiveness. Further, such decisions are critical in the face of limited availability of public funds to improve animal waste treatment. This leads to questions such as what is the most effective improvement strategy (e.g., which farms should be targeted first for improvement) within a limited budget, or what is the incremental cost of additional improvement and the tradeoff between them? These decisions should also consider localized needs for improvements (e.g., reduction of odor problems in locations close to residential zones, while reductions of nutrient levels in locations close to sensitive water bodies) when identifying a strategy.
The effectiveness of a swine waste treatment technology depends on many factors, including the size of the swine production operation and the location and site characteristics that dictate the feasibility of a technology for a particular farm. In addition, the cost of alternative treatment technologies will vary for each farm. A “one-size-fits-all” solution is not possible. Recommendations for integrated animal waste management within an area (i.e., a collection of farms) should identify a collective strategy that lists a technology or no-treatment option for each farm. The strategies may vary depending on the design criteria. For example, the goal may be to minimize cost to meet one or a combination of reduction targets for nitrogen, phosphorus, odor and ammonia volatilization, or to maximize the reduction of nitrogen within a budget limit, and subject to other targets.
Other issues to be faced by planners and managers may be equity issues that may arise from different improvement recommendations for different farms, and public and private costs of changing treatment technology for a geographic region.
Objectives of
Research
· Develop an optimization model for generating lowest cost solutions to meet a collective environmental target in the discharge of waste from hog farms.
· Develop the model so that to help examine alternative strategies for integrated waste management in swine production units.
· Integrate existing databases on farms and treatment technologies for North Carolina into this framework.
Tasks
1. Compile data (on sizes, operating conditions, current treatment technology options, and location) of existing farms. *
2. Compile economic and technological data on available swine waste treatment technologies. *
3. Construct a decision model for identifying integrated waste management strategies that are cost effective and technologically feasible to meet different goals.
4. Implement this model as a Microsoft Excel spreadsheet (if possible) and facilitate its interfacing to an existing model that analyzes different treatment technologies for hog waste (3).
5. Obtain results from the model and examine implementation options.
6. Final report preparation.
* If adequate data is not obtained in a timely manner, estimated values for treatment capabilities and cost of different treatment technologies will be used. The CAAWSST (3) will be used to generate data if necessary.
References
(1) North Carolina Department of Environment and Natural Resources. 1999. Framework for the Conversion of Anaerobic Swine Waste Lagoons and Sprayfields. URL (http://www.ehnr.state.nc.us/EHNR/files/hogs/hogplan.htm).
(2) Williams, M. 1999. Alternative Animal Waste Management Technologies: A Status Report, June 8, 1998. College of Agricultural and Life Sciences, Animal and Poultry Waste Management Center, North Carolina State University, Raleigh, NC. URL (http://www.cals.ncsu.edu/waste_mgt/1999report.html).
(3) Classen, J., Liehr, S., and Anastasiou, C. March 22, 2000. Computer Assisted Animal Waste System Selection Tool (CAAWSST): A status update to the working committee. Presentation and personal communication notes.