Ecological effects of contaminants in McCoy Branch, 1991--1993

Abstract

Thii report has been reproduced directly from the best available copy.AvallaMe to DOE and DOE contractors from the Office of Scientific and Techni. yearly ratio of energy derived from gas compared to that from coal is approximately 5 to 1; a higher percentage of coal was used in winter months. A dry vacuum system was installed in May 1990 to collect dry fly ash. Fly ash is now transported to a landfill, and all sluice water discharge to Rogers Quarry has been terminated. By January 1994, a bottom ash dewatering system was installed and functional at the steam plant. The wet bottom ash is sent through the system and the ash residue is trucked to a landfill. The wash down water generated by this process is recycled in the system for future wash down use. The last actual discharge of wet bottom ash to Rogers Quarry occurred in July 1993. CONTENTS (continued)APPENDIX Biological Monitoring Program LIST OF FIGURES Biological Monitoring ProgramPrevious biological monitoring of McCoy Branch was conducted from 1989 through 1990 and included evaluations of instream toxicity, bioaccumulation (in Rogers Quarry), fish community, and benthic community parameters @yon et al. 1992). This biomonitoring indicated that McCoy Branch was receiving low to moderate stress. The instream toxicity studies produced only limited effects on fathead minnow and Ceriodaphnia survival and fecundity in 7-d laboratory tests. In situ snail studies indicated that more stress was seen below Rogers Quarry than above it. Bioaccumulation studies indicated that selenium, arsenic, and possibly thallium were elevated in largemouth bass from the quarry in comparison to levels in reference fish. These fish also had severe deformities present in bony structures.Similar deformities in fish from the stream proper were noticed by the fish community studies in McCoy Branch below the quarry. A fish community was absent in McCoy Branch above the quarry, while the stream immediately below the quarry had an atypical community for a small stream with many species tolerant of degraded conditions. The benthic macroinvertebrate community assessment indicated the maximum impacts were above the quarry, with all sites showing more impact than companion reference sites. Some temporal recovery was noted in the benthic community above the quarry, which was not seen at downstream sites. Overall, McCoy Branch demonstrated moderate impacts on the biological communities, with perhaps some improvement since the cessation .of fly ash disposal. If the system is beginning to recover, then the additional biomonitoring covered in this report should detect further improvement in the above areas. WAWR QUALITYThe water quality data show that although some metal concentrations, levels of radioactivity, and organic constituents are still above reference values, the average values of these contaminants in surface water and groundwater samples in McCoy Branch watershed generally have been decreasing yearly since 1988. During this period, nitrate-nitrogen values have actually fallen b...

Reviews of Environmental Contamination and Toxicology Volume 236

“…Slow colonization in Ephemeroptera was observed for instance, after long-term heavy metal discharge (Ryon 1992(Ryon , 1996Smith 2003 ) or due to low ambient temperatures (Flory 1999 ;Flory and Milner 1999 ;Milner et al 2000 ). Slow colonization in Ephemeroptera was observed for instance, after long-term heavy metal discharge (Ryon 1992(Ryon , 1996Smith 2003 ) or due to low ambient temperatures (Flory 1999 ;Flory and Milner 1999 ;Milner et al 2000 ).…”