In QC, TOC levels in the spring, summer,
fall and winter decreased considerably (2.1mg/l, 2.6mg/l, 3.2mg/l,
1.9 mg/l, respectively) through the treatment processes. These differences
in organic content in drinking water between NL and QC small
systems may contribute to explaining the observed difference in HPC values in the DS between both provinces (as free Cl levels cannot explain
these differences) (Fig. 3a and b).