tank with the first compartment equal to 1/2 to 2/3 of the total volume provides better
nonfiltrable residue removal. The compartments may be individual tanks placed in
series or sections enclosed in one continuous shell with watertight partitions separating
the compartments (see Figure 1-15). Although capacity is the major consideration in
selection of a tank, the following points are also important.
Figure 1-15. Septic tank with 2 compartments.