Another difference between the two studied regions is
the size of the systems. Even if there is no precise information about
the residence time, Table 1 reports higher populations for systems in
QC than in NL. In fact, higher water demand reduces water residence
time,minimizingwater stagnation, and, consequently, reduces DBP formation.
It is important to remark that average levels of DBPs in NL are
about three times those in QC. The occurrence in drinking water of
DBP levels systematically above the guideline thresholds could potentially
increase the risk for health-related problems, such as cancer and
reproductive malfunctions (Nieuwenhuijsen, 2005; Richardson et al.,
2007).