Spring 2004
Non-basin technologies for open feedlots
by Gene Tinker and Deb Frundle, Iowa Department of Natural Resources
The Iowa Plan for Open Feedlots was designed to bring open feedlots into environmental compliance by the year 2006. Today, many open feedlots do not have adequate run-off control structures to properly protect Iowa waters. All open feedlots are required to have solid settling as a minimum control measure. Feedlots with more than 1,000 animal units, or lots with between 301 and 1,000 animal units with a stream running through the lot or a direct man-made conveyance to water, are required to have a National Pollution Discharge Elimination System (NPDES) permit. If an NPDES permit is needed, the feedlot is also required to have designed containment to receive the effluent or liquid wastewater, after the solids from the runoff have been settled.
Most systems use a runoff control basin (now called solid open feedlot effluent basin by Iowa law) to catch the effluent from solid settling, and hold the effluent until it is land applied. The size of the basin is dependent on the amount of feedlot runoff and on how often the basin is emptied.
The U.S. Environmental Protection Agency (EPA) has revised the regulations for Concentrated Animal Feeding Operations (CAFO) to allow the use of alternative technologies to control the effluent from lots that need an NPDES permit. Therefore, non-basin, or alternative technologies are of great interest to producers as potentially cost-effective in total containment. Nonetheless, EPA has established relatively strict criteria for determining if a proposed alternative will be acceptable.
The Iowa Department of Natural Resources (DNR), Iowa State University (ISU), and the Iowa Cattlemen’s Association have been working cooperatively to develop a system to identify open feedlots that may be candidates to use non-basin technology. To achieve this goal, the DNR must be able to verify if the designed systems adequately protect the waters in the state. Verification includes three major components: computer models, minimum criteria to help predict the success of non-basin systems on specific open feedlots, and monitoring to evaluate the effectiveness of the systems.
Iowa State University is developing computer models to compare the effectiveness of non-basin systems with a standard basin system. By using information on feedlot size, drainage area, distance from streams, and soil type and slope, the models can predict the effectiveness of an alternative design for an individual site.
Minimum criteria are being developed so that producers can work with professionals to determine if a non-basin system can provide adequate environmental protection for a specific feedlot. Open feedlot operators will be able to use these criteria to discuss possibilities with DNR environmental specialists and geologists, ISU staff or consulting engineers.
Infiltration basins and vegetative filter strips are the primary systems being considered. If properly designed and maintained, these systems will have a dense vegetative cover. Consequently, nutrients and pollutants will be reduced as the effluent is filtered through the soil, removed by evapotranspiration, attached to roots of vegetation, and taken up by plants. Other alternatives, such as composting, may be considered if an effective operational plan is developed.
Feedlots that receive approval to design, construct and operate a non-basin system must also agree to a multi-year monitoring plan. Monitoring will include sample collection of effluent, groundwater, and any potentially receiving stream to analyze nutrient treatment and pollutant dispersion through the system. These results will be compared with the model predictions and evaluated to ensure that no detrimental environmental impact has occurred. Non-basin systems that are not providing adequate environmental performance will be required to be replaced by a conventional system.
Open feedlot operators who would like to learn more about non-basin systems or discuss whether their feedlot could be considered for such a system should contact Deb Frundle (515) 242-6849 or Gene Tinker (515) 281-3103 at the Iowa DNR.
