Waste Characterization Studies For High-Density
Raceway Production of Catfish—
The Gallatin Catfish Project
JOHN A. GORDON, Supervisor
Special Projects Staff
Water Quality Branch, Division of Environmental Planning
Tennessee Valley Authority
Chattanooga, Tennessee 37401
INTRODUCTION
TVA sponsored waste characterization studies at the Gallatin catfish project during
the 1973 growing season to ensure that waste handling problems would be adequately
evaluated for any full-scale catfish production facility. The waste characteristics were
determined by four all-day surveys conducted at various times during the growing season.
Details of these surveys are presented later in this report.
The Gallatin catfish project is currently being operated under a joint agreement between TVA and Cal Maine Foods, Inc., of Jackson, Mississippi. The overlying theme of the
current research is the production of edible catfish using heated condenser discharge water
from the Gallatin Steam Plant incorporated into high-density raceway culture.
The facility consists of 10 concrete raceways each 50 feet long by 4 feet wide by 4 feet
deep. Water depth can be varied but was held at 3.5 feet during the 1973 studies. The
raceways were designated 1 through 10 by permanent marking. Stocking densities were as
follows:
Raceways I, 2, and 3 10,000 fish
Raceways 4, 8, 9, and 10 15,000 fish
Raceways 5, 6, and 7 20,000 fish
The initial experiments included constant flow studies and continuous aeration of the
raceways; however, the aeration system did not function adequately and the flows had to be
increased with growth of the fish in order to maintain the supply of dissolved oxygen to the
fish.
WASTE CHARACTERIZATION STUDIES
A couple of semiquantitative waste surveys were carried out during the early
experimental period of 1971 and 1972. These preliminary surveys showed that the principal
items of interest were organic strength as measured by biochemical oxygen demand and/ or
chemical oxygen demand (BOD, COD), solids content and nutrient content. These
parameters were to be assessed during the three major daily activities occurring during
catfish rearing: the fish feeding periods, the metabolic periods, and the raceway cleaning
periods. Normal operation consists of an early morning feeding lasting for about 1 hour
followed by a 5-minute flushing of the raceways to remove settled solids, and then a 10-11
hour metabolic period prior to late evening feeding which renews the cycle.
Four waste surveys were performed during 1973 as growth of the fish progressed from
fingerlings to adults. Stocking of the raceways occurred on March 8, and surveys were
performed on April 3, May 23, July 5, and August 5. Major emphasis was placed upon
establishing the increased concentrations of waste constituents resulting from the catfish
rearing operation in such a manner as to provide predictive capability for future operations.
The data obtained from these surveys are presented in Tables 1, II, III, and IV. These data
were then used to obtain the concentration increases which are given in Tables V, VI, VII,
and VIII. These concentration increases were combined with raceway flows to obtain the
waste discharges in pounds per day as shown in Tables IX, X, and XL The following
discourse will analyze the information presented by Tables I through XI on a parameter-by
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