Figure 2 showed effects of total phosphorus on suspending bacterial regrowth in drinking water distribution
system. Overall, the higher the content of total phosphorus in the network was, the more the number of bacteria
(HPC) was. Correlation coefficient between TP and HPC was 0.137 (n = 45), and the correlation was poor. It
showed that correlation was poor through calculating the Correlation coefficient(r) between the average TP of each
different sampling point, maximum TP and the average HPC of each different sampling point, maximum HPC. This
explained that the total phosphorus was not directly related to the suspended bacterial growth in the network, namely
TP was not the key factor that affect the bacterial regrowth. This may be because TP detected by water sample
included not only microbially available phosphorus but also included phosphorus that cannot be available by
Microorganisms. The growth of bacteria was restricted by microbially available phosphorus, and irrelevant with
other forms of phosphorus.