Aquatic Field Survey at Holston Army Ammunition Plant, Kingsport, Tennessee.

Overall effects of munitions effluents from the Holston Army Ammunition Plant during the summer of 1975 were most clearly observed in the periphytic community and were confined to the vicinity of the waste outfalls. Marked increases in heterotrophic biomass and reduction in autotrophic populations were noted. Species composition shifts among the diatoms growing on artificial substrates suggested toxic manifestations from munitions related effluents. Effects on the periphyton were observed in water containing as little as 20 micrograms/liter RDX. Direct relationship of RDX residues to biotic response in this system must be approached with caution. The changing chemical environment due to variable waste discharge, upstream waste inputs, and flow variability make it virtually impossible to closely quantify typical conditions at a given station. Many of the effects may also be due to ancillary nitrogen and carbon discharges or to synergism between RDX and combinations of other factors. The Holston environment is one of eutrophic conditions and biological stress due to upstream discharges; thus sensitive organisms which would be expected to respond to threshold biotoxicity from RDX do not occur in the reach impacted by HAAP Area B. Conservative estimates, however, place a critical range of 20 to 100 micrograms/liter RDX for periphyton in water containing munitions effluent.