Tuesday, November 6, 2007 - 10:00 AM
230-2
Environmental Issues Associated with the Reuse of CAFO Waste Water.
Concentrated animal feeding operations (CAFOs) generate large volumes of manure and manure-contaminated wash and runoff water. Transportation, storage, and treatment of manure and manure-contaminated water are costly. The large volume of waste generated, and the lack of disposal areas, further limits effective manure management. When applied to land at agronomic rates, CAFO waste water has the potential to be a valuable fertilizer and soil amendment that can improve the physical condition of the soil for plant growth and reduce the demand for high quality water resources. However, excess amounts of nutrients, salts, pathogenic microorganisms, and pharmaceutically active compounds (antibiotics and hormones) in CAFO waste water can adversely impact soil and water quality. The Environmental Protection Agency currently requires that CAFO waste application follow a Comprehensive Nutrient Management Plan (CNMP). A CNMP is a design document that sets rates for waste application to meet the water and nutrient requirements of the selected crops and soil types, and is typically written so as to protect surface water resources. The tacit assumption is that a well-designed and executed CNMP ensures that all lagoon water contaminants are taken up in the root zone, so that groundwater is inherently protected. The validity of this assumption for all lagoon water contaminants has not yet been thoroughly studied. This review paper provides an in-depth discussion of our current levels of understanding on the environmental impact and sustainability of CAFO waste water reuse. Specifically, we address the source, composition, application practices, environmental issues, and reuse considerations associated when using CAFO waste water.
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