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Home > AFO Strategies for Source Water Protection > Reactive Solutions for Managing and Treating AFO Wastes

*Source Water Protection

Other Treatment Systems for Animal Waste

Summaries and relative evaluations of potential treatment methods for AFO wastes are provided by the following references:

'Treatment Technologies and Best Management Practices' - Chapter 8 in Development Document for the Proposed Revisions to the NPDES Regulation and the Effluent Guidelines for CAFOs (USEPA, 2002c)
Agricultural Waste Management System Component Design - Chapter 10 of the USDA's Agricultural Waste Management Field Handbook provides descriptions of design criteria for numerous animal waste treatment and handling methodologies (USDA, 1999)
Manure Treatment Options (LPES Curriculum Lesson 25)
Biological Processes (LPES Curriculum Lesson 43-4)
Solid-Liquid Separation (LPES Curriculum Lesson 43-3)
A slide show on Treatment of Animal Wastes from a workshop held September 19 to 20, 2005.

Summary:

Treatment may include physical, biological, and chemical processes, and is designed to reduce the pollution potential of the waste (e.g., rotating biological contactors and oxidation ditches) or change the solids content for handling purposes (e.g., mechanical separation, settling basins, and drying). Treatment systems can be designed for removal of the contaminants of concern, just as with conventional municipal and industrial water and wastewater treatment, and can be used to stabilize organic matter and nutrients (N and P), control pathogens, reduce odor and gas, or improve handling characteristics during storage and spreading. As an example, anaerobic digesters are used at some facilities for manure treatment with good success (e.g., Moser, 2006; www.epa.gov/agstar/resources.html). Some farms use treatment systems to help deal with milk house waste or egg wash water. Proper operation and maintenance of these facilities is essential for achieving the desired treatment results.

Stabilization of nutrients by alum (aluminum sulfate) is a relatively new area of research (USEPA, 2004b), and an area where a water utility can use their own treatment plant's residuals to help in source water protection from agricultural operations. Application of alum and ferric hydroxide water treatment residuals to agricultural land can provide an inexpensive disposal option for utilities and help in source water protection by binding to phosphorus and reducing phosphorus solubilization after land application of manure and litter (DeWolfe, 2003; Walker, 2000). Alum applied to dry litter in poultry houses also reduces ammonia gas emissions from the litter, which in turn improves bird health, increases weight gains and reduces mortality, thus saving the producer money. In fact, savings from these benefits may more than offset the cost of the alum (Walker, 2000).

Cost and maintenance considerations are usually prime factors when considering more advance treatment technologies versus conventional land spreading of manure. Often advanced treatment is seriously considered only when substantial water pollution risks or odor problems are identified in nutrient management plans.