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The water level height is calculated as the sum of elevation of the sed slopes, 2*outerdiameter of the pipe used for the sed plate frame, height of the lamella, height of the water above lamella, and the distance between the top of the slopes and the bottom of the lamella. Two other factors also taken into consideration are the thickness of the concrete ledge used to hold up the launder on the inlet channel side and the extra space between the top of the lamella and the launder to offset any error during construction. Because of these two variables there is significant space between the top of the lamella and the launders, which results in an increase in the height of the water in the sedimentation tank, leading to a taller sedimentation tank.

{latex}
\large
$$
HW_{Sed} = Z_{SedSlopes} + H_{SedBetween} + 2*outerdiameter(ND_{SedPlateFrame} ) + H_{SedPlate} + H_{SedAbove} + T_{ConcreteMin} + S_{LamellaLaunder}
$$

{latex}

where, the elevation of the sed slopes is defined as:

{latex}
\large
$$
Z_{SedSlopes} = Z_{SedSludge} + H_{SedTopSlope} + H_{SlopeThickness}
$$

{latex}

The calculations of the lamella height can be found here.

The launders leaving the sedimentation tanks were designed in a similar manner as the sedimentation sludge drain manifold. The height of water above plate settlers has been defined as:

{latex}
\large
$$
H_{SedAboveW} = outerdiameter(ND_{SedLaunder} ) + HL_{SedLaunder}
$$

{latex}

The calculations of dimensions of the inlet channel can be found here.

Finally, therefore:

{latex}
\large
$$
H_{Sed} = HW_{Sed} + H_{PlantFreeboard}
$$

{latex}

and

{latex}
\large
$$
Z_{MP} = HW_{Sed} - HW_{InletChannel}
$$

{latex}