SS4.11 Water and Society - Science and Management in a Social and Economic Context
Date: Thursday, June 13, 2002
Time: 10:15:00 AM
Location: Sidney
 
McGahaGD, Center for Watershed Research, Univ. of Louisville, Louisville, USA, gdmcga01@athena.louisville.edu
Jack, J, D, Center for Watershed Research, Univ. of Louisville, Louisville, USA, jdjack01@athena.louisville.edu
 
TRIHALOMETHANE PRECURSORS IN A EUTROPHIC RESERVOIR AND ITS TRIBUTARY
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Algae and dissolved organic carbon (DOC) can be potent precursors for trihalomethane formation potential (THMFP). The experimental objective was to determine the relative importance of algal growth and DOC in the generation of trihalomethanes. Twelve one-liter water samples were collected from both the Upper Salt River and Taylorsville Reservoir. Six samples from each were filtered to remove the majority of phytoplankton present. Three samples from each of these groups were then covered in aluminum foil to prevent light exposure. All samples were incubated at 25 degrees Celsius during18 hrs light and 6 hrs dark for five days. Results show that THMFP in water collected from the tributary increased 18% while THMFP decreased 9% in water collected from the reservoir. Chlorophyll a and DOC showed positive correlations to THM formation ( 0.84 and 0.75 respectively). In addition, UV absorbance of samples was analyzed post incubation to determine if a correlation existed between UV absorbance and THMFP. A positive correlation (0.93) was found. Better control of nutrient loading and/or removal of phytoplankton before treatment should decrease the THMFP in raw waters.