This allows for the recommended 6 inches of freeboard if a 6-inch storm occurs when the liquid level is one foot below the top of the tank. Figure 2 shows the volume fractions considered in the design of dairy waste tanks in Missouri. Schematic of volume fractions in manure tank design. Table 1 lists typical tank sizes for various herd sizes in Missouri. These values are averages only and should not be used in lieu of a specific design.
Deep tanks offer the following advantages.
A smaller surface area requiring less space. Efficient use of mechanical agitation. Design loads on the exterior of walls consist primarily of lateral earth pressures, surcharge pressures and hydrostatic pressures. Exterior hydrostatic pressures vary with the water table level and degree of drainage. Tank covers must be designed for dead loads, and equipment and livestock loads, if applicable.