Bromide, Chloride, and Sulfate Concentrations, and Specific Conductance, Lake Texoma, Texas and Oklahoma, 2007-08

Bromide, Chloride, and Sulfate Concentrations and Loads at U.S. Geological Survey Streamflow-Gaging Stations 07331600 Red River at Denison Dam, 07335500 Red River at Arthur City, and 07336820 Red River near DeKalb, Texas, 2007-09

“…These low concentrations do not warrant exclusion from regression analyses as outliers; there is nothing to indicate they resulted from errors introduced during sample collection or analysis. On the contrary, the low concentrations are consistent with dilution resulting from a large influx of runoff to Lake Texoma Baldys (2009). documented decreases in bromide concentrations throughout Lake Texoma after the large inflows that began in late June 2007.…”

“…During wet periods, releases from Lake Texoma can vary greatly depending on reservoir management needs; the U.S. Army Corps of Engineers releases water from Lake Texoma to generate power and manage inflows. The hydrology and climatology of the drainage basin upstream from Lake Texoma, which has a major effect on the quantity and quality of flows released through Denison Dam, are described in Baldys (2009). (Westfall and Cummings, 1963).…”

“…The U.S. Environmental Protection Agency (2006a) has developed a Stage 2 disinfectants and disinfection byproducts (DBP) rule to improve drinking-water quality and provide additional protection from DBP. Concentrations of bromide and other salinity-related constituents and physical properties in Lake Texoma were characterized by the U.S. Geological Survey (USGS) in a previous report (Baldys, 2009). Median bromide concentrations ranged from 0.28 mg/L in the Washita arm of Lake Texoma to 0.60 mg/L in the Red River arm of the lake.…”

“…Median concentrations of chloride ranged from 122 mg/L in the Washita arm of Lake Texoma to 431 mg/L in the Red River arm of the lake. Because elevated concentrations of salinity-related constituents, including chloride and sulfate, have been measured in Lake Texoma (Atkinson and others, 1999;Baldys, 2009), there is a concern that chloride and sulfate concentrations in the reach of the Red River downstream from Lake Texoma to DeKalb, Tex., might at times exceed applicable secondary maximum contaminant levels (SMCLs) of the "Texas Surface Water Quality Standards" for drinking water (Texas Commission on Environmental Quality, 2003).…”

“…As a companion to the study summarized in Baldys (2009), the USGS, in cooperation with the City of Dallas Water Utilities Division, did a study to characterize bromide, chloride, and sulfate concentrations and loads at three USGS streamflow-gaging stations on the reach of the Red River from Denison Dam, which impounds Lake Texoma, to the U.S. Highway 259 bridge near DeKalb, Tex. Discrete waterquality data collected during January 2007-February 2009 and con tinuous water-quality data collected during March 2007-February 2009 were evaluated at USGS streamflowgaging stations 07331600 Red River at Denison Dam near Denison, Tex.…”