Watershed sources of disinfection byproduct precursors

A series of field and laboratory investigations was conducted aimed at characterizing disinfection byproduct (DBP) precursor levels in the Wachusett Reservoir watershed. Samples were collected from spatial based and storm event sampling campaigns, as well as laboratory leaching experiments. These were analyzed for DOC, TOC and DBP precursors in an effort to characterize the changes in precursor levels and natural organic matter (NOM) character in this watershed. Based on these data, it was proposed that freshly leached NOM is relatively poor in DBP precursors due to the abundance of non-reactive carbohydrates. As these compounds undergo biodegradation within the watershed, the measured specific DBP precursor level rises, because the more reactive materials (e.g. lignins, phenolics) are also more persistent.