There may be some confusion about who is required to file a manure management plan with the Iowa DNR and the county board of supervisors. More specifically, much of the confusion appears to be over the proper way to determine the animal capacity of a confinement operation.

A manure management plan is required for a confinement feeding operation with formed manure storage and a capacity of more than 500 animal units (1,250 head of swine weighing more than 55 pounds or 5,000 head of swine weighing 15 to 55 pounds) if the operation was constructed or expanded after May 31, 1985.

As set by DNR rules, animal capacity is the maximum number of animals that will be confined at any one time. Animal capacity is not determined by the dimensions of the building. Thus, even though a confinement operation with concrete manure storage could possibly hold more than 1,250 head weighing more than 55 pounds, if the operation is never stocked with more than that number an MMP is not required.

Several key points to remember are: (1) More than 1,250 pigs may be placed in a finishing operation as long as there are no more than 1,250 head on site when the pigs reach 55 pounds. For example, a wean-to-finish operation may be double-stocked with weaned pigs if there are no more than 1,250 head on site when they reach 55 pounds; (2) The operation’s capacity may change over time. If the stocking rate will be increased to more than 500 animal units without any new construction, a manure management plan must be filed with the DNR and the county before the increase; and (3) Pigs in open lots are not included in the calculation of confinement animal capacity.

If anyone has questions, please call the IPPA at 800-372-7675.