Ecological risk assessment of the benthic invertebrate community of the Clinch River/Poplar Creek system
- Oak Ridge National Lab., TN (United States)
The CERCLA remedial investigation for the Clinch River/Poplar Creek included the benthic invertebrate community as an endpoint. The assessment endpoint was defined as a 20% reduction in species richness or abundance of the benthic invertebrate community in the Poplar Creek embayment or in any of three reaches of the Clinch River. Screening of chemical concentrations in sediment and pore water against benchmarks determined that 38 chemicals were contaminants of potential ecological concern (COPECs). Pore water COPECs were limited to fifteen metals, benzoic acid, and bis(2-ethylhexyl)phthalate. Many COPEC concentrations exceeded benchmarks by two to three orders of magnitude. Mercury was the primary sediment COPEC, although PCBs, PAHs, and other metals were also potentially toxic. Comparison of the distributions of COPEC concentrations with the distributions of literature toxicity values indicated widespread toxicity of several COPECs. Sediment toxicity tests indicated that a few sediment samples were toxic, but in general very little toxicity and no clear spatial trends were observed. Whole sediment tests were more sensitive than pore water tests. This may indicate that sediment-associated contaminants contribute more to risks. The benthic invertebrate community data were evaluated using canonical discriminant analyses. Communities in the Operable Unit (OU) were less diverse than in lower Tennessee Valley mainstem reservoirs, but similar to other upper valley reservoir communities. Abundance and taxa richness were reduced at some sites, but were not consistently reflective of contaminant sources. Decreased taxa richness and abundance in upper Poplar Creek may indicate contaminant sources upstream of the OU. These conflicting results are a challenge to ecological risk characterization based on weight-of-evidence. The process of weighing the evidence will be presented.
- OSTI ID:
- 212060
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9617%%376
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ecological risk assessment in a large river-reservoir. 3: Benthic invertebrates
Remedial investigation/feasibility study for the Clinch River/Poplar Creek operable unit. Volume 4. Appendix F
Related Subjects
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
CLINCH RIVER
REMEDIAL ACTION
STREAMS
OAK RIDGE RESERVATION
MERCURY
TOXICITY
PHTHALATES
POLYCHLORINATED BIPHENYLS
POLYCYCLIC AROMATIC HYDROCARBONS
WATER POLLUTION
BIOLOGICAL INDICATORS
INVERTEBRATES
SENSITIVITY
US SUPERFUND
INTERSTITIAL WATER
MONITORING
ECOLOGICAL CONCENTRATION
SITE CHARACTERIZATION
BENTHOS