Formed Manure Storage Structure Missouri does not have design specifications for formed manure storages printed in regulations. Permitting requirements are that these formed manure storages must be designed by a professional engineer. Designs must conform to design criteria as printed by the American Concrete Institute (ACI), Natural Resource Conservation Service (NRCS) Design Specifications, Midwest Plan Service (MWPS) or other accepted concrete design standards. Return to Step 3  |   Return to Overview