Abstract
Dissolved organic carbon (DOC) in surface water affects finished drinking water quality, in particular the formation of halogenated disinfection by-products (DBP). In Missouri, 62% of the public is served by 221 drinking water systems utilizing surface waters. Both the quality and quantity of DOC impacts DBP formation and it is known that allochthonous DOC is more reactive with halogens than autochthonous DOC. Our goal in this study was to determine the relative influence of allochthonous and autochthonous DOC on the DBP precursor pool. Samples were collected from 76 reservoirs spanning a 12 month period from January 2004 through December 2004 and regression models were developed for DBP surrogates. In a cross-system analysis of annual reservoir means, 77% of the variation in DOC [1.35 – 12.37 mg/L] was explained by hydraulic flushing rate. Total phosphorus [4.0 – 32.2 μg/L] and DOC accounted for 97% of the variation in chlorine demand [4.5 19.2 mg/L] while total phosphorus and hydraulic flushing rate x explained 88%. Additionally, time-series plots were compared to stream gauge data and UV254 absorbance peaks coincided well with peaks in the hydrographs. Chlorophyll [0.6 – 195.2 μg/L] was weakly correlated with the DBP surrogates within and across seasons (R = 0.31 – 0.62). These results indicate that watershed hydrology and allochthonous inputs controlled the DBP precursor pool in Missouri reservoirs in 2004 and that hydraulic flushing rate may have more predictive value modeling DBP formation than chlorophyll.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call