Harmful algal blooms: A case study in two mesotrophic drinking water supply reservoirs in South Carolina

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Algal blooms can be harmful and a nuisance in a variety of aquatic ecosystems, including reservoirs and lakes. Cyanobacterial(blue-green algae) harmful algal blooms are notorious for producing both taste-and-odor compounds and potent toxins that may affect human health. Taste–and-odor episodes are aesthetic problems often caused by cyanobacterial-produced organic compounds (geosmin and methylisoborneol) and are common in reservoirs and lakes used as source water supplies. The occurrences of these taste-and-odor compounds and toxins (like microcystin) can be sporadic and vary in intensity both spatially and temporally. Recent publications by the U.S. Geological Survey address this complexity and provide protocols for cyanotoxin and taste-and-odor sampling programs. A case study conducted by the U.S. Geological Survey, in cooperation with Spartanburg Water, monitored two mesotrophic reservoirs that serve as public drinking water supplies in South Carolina. Study objectives were (1) to identify spatial and temporal occurrence of the taste-and-odor compound geosmin and the cyanotoxin microcystin and (2) to assess the associated limnological conditions before, during, and after these occurrences. Temporal and spatial occurrence of geosmin and microcystin were highly variable from 2007 to 2009. The highest geosmin concentrations tended to occur in the spring. Microcystin tended to occur in the late summer and early fall, but occurrence was rare and well below World Health Organization guidelines for finished drinking water and recreational activities. No current U.S. Environmental Protection Agency standards are applicable to cyanotoxins in drinking or ambient water. In general, elevated geosmin and microcystin concentrations were the result of complex interactions between cyanobacterial community composition, nutrient availability, water clarity, hydraulic residence time, and stratification.

Study Area

Publication type Conference Paper
Publication Subtype Conference Paper
Title Harmful algal blooms: A case study in two mesotrophic drinking water supply reservoirs in South Carolina
Year Published 2010
Language English
Publisher Clemson University Center for Watershed Excellence
Contributing office(s) South Atlantic Water Science Center
Description 5 p.
Larger Work Type Conference Paper
Larger Work Subtype Conference Paper
Larger Work Title Proceedings of the 2010 South Carolina Water Resources Conference
Conference Title 2010 South Carolina Water Resources Conference
Conference Location Columbia, South Carolina
Conference Date October 13-14 2010
Country United States
State South Carolina
Online Only (Y/N) N
Additional Online Files (Y/N) N
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