BRANDY BRANCH RESERVOIR
MARSHALL, HARRISON COUNTY, TEXAS
BACKGROUND AND STATEMENT OF ISSUES
The Texas Department of Health Seafood Safety Division (SSD) requested that the Health Risk Assessment and Toxicology Program reevaluate the current advisory limiting consumption of fish taken from Brandy Branch Reservoir, a 1,200 acre cooling reservoir for Pirkey Power Plant and operated by Southwestern Electric Power Company (SWEPCO). Brandy Branch Reservoir is located 10 miles southwest of Marshall in Harrison County, Texas. During the late 1970's, several power plant cooling reservoirs in Texas received discharges from ash ponds containing elevated selenium levels, resulting in increased selenium concentrations in fish. An investigation of a series of fish kills in waterbodies near power plants in the early 1980's implicated elevated levels of selenium in fish tissue and water. The Texas Parks and Wildlife Department (TPWD) reported elevated levels of selenium in Brandy Branch fish during this time. From 1986-1989, TPWD reported that average selenium concentrations in Brandy Branch fish increased from 0.81 to 2.29 ppm. The reasons for this increase are unknown but may include sampling variations, seasonal variations in selenium concentrations, or continued input of selenium into the reservoir during this period.
Since the fish kills, the Texas Department of Health (TDH), TPWD, and SWEPCO have worked cooperatively to monitor selenium levels in fish tissue. In 1992, TDH issued a fish consumption advisory for the reservoir after it was determined that the levels of selenium in fish could pose a potential health risk. The advisory recommended that adults consume no more than one eight-ounce meal each week and children seven years of age and older consume no more than one four-ounce meal each week. Children six and under, pregnant women, or women who may soon become pregnant were advised not to consume the fish. Additionally, persons consuming fish from the reservoir were advised not to consume mineral dietary supplements with selenium exceeding 50 micrograms per day.
In 1996 and 1997, TDH collected 17 fish (13 largemouth bass, 1 white bass, and 3 white crappie) for a re-evaluation of the present fish consumption advisory. The concentration of selenium in the fish ranged from 0.46 to 1.79 ppm with an overall average concentration of 0.87 ppm (Table 1).