Fig. 4From: Comparison of the microbiomes of two drinking water distribution systems—with and without residual chloramine disinfectionAlpha diversity of water-main biofilms, drinking water, and under tubercle. a Shannon index (higher values = greater richness and evenness) and b inverse Simpson index (higher values = greater evenness). Shared symbols (e.g., * and †) indicate no significant group-wise difference (i.e., P>0.05), and bars indicate mediansBack to article page