Interpreting the Narrative Nutrient Management Approach in the 2008 EPA CAFO Rule.

In December 2008 USEPA approved a revision to rules governing how permitted concentrated animal feeding operations (CAFOs) manage their manure.  In response to a 2005 court ruling the revised rule requires that the nutrient management plan be part of the terms and conditions of the CAFO’s permit.  The revised rule further stipulates one of two approaches must be used for calculating field-specific manure application rates on fields controlled by the CAFO: the linear approach or the narrative approach.  The narrative approach allows the farmer to use standardized testing procedures and protocols incorporated as terms of the permit to derive field-specific rates of manure application.  Certain field characteristics, necessary to determine manure application rates, cannot be derived from a standardized test or by following a specific protocol.  As a result, these field characteristics must be incorporated as terms of the permit.  The narrative rate thus requires integrating both standardized tests and protocols and selected field-specific parameters into the terms and conditions of the permit.  After a careful review of the final rule we concluded that field-specific parameters of field location, field size, potential crops and potential crop yield goals should be terms of the permit.  We also provide an example of how the narrative terms needed to calculate a field-specific rate of manure application from these parameters can be integrated into the terms and conditions of a general permit.