Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling

Lake and Reservoir Management
By: , and 



Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and sediments in the reservoir. The purpose of this study was to assess if release of DOC from reservoir sediments containing ferric chloride coagulant was a significant source of DOC to the reservoir. We examined the source-specific contributions of DOC using a profiling system to measure the in situ distribution of optical properties of absorption and fluorescence at various locations in the reservoir. Vertical optical profiles were coupled with discrete water samples measured in the laboratory for DOC concentration and optical properties: absorption spectra and excitation emission matrix spectra (EEMs). Modeling the in situ optical data permitted estimation of the bulk DOC profile in the reservoir as well as separation into source-specific contributions. Analysis of the source-specific profiles and their associated optical characteristics indicated that the sedimentary source of DOC to the reservoir is significant and that this DOC is labile in the reservoir. We conclude that optical profiling is a useful technique for understanding complex biogeochemical processes in a reservoir.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling
Series title Lake and Reservoir Management
DOI 10.1080/07438140809354848
Volume 24
Issue 4
Year Published 2008
Language English
Publisher Taylor and Francis
Publisher location New York, NY
Contributing office(s) California Water Science Center
Description 11 p.
First page 381
Last page 391