DlSTRlBUTlON OF Q S T IThis report has been reproduced directly from the best available copy.Available to DOE DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein t o any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER 2-2 G-40Soil-plant uptake factors fiom collocated soil and plant samples collected G-52Soil-plant organic contaminant uptake factors using octanol water F-18HQs for contaminants of potential concern for white-tailed deer on the ORR ..... ACKNOWLEDGMENTSThis report is the result of the efforts, contributions, and support of many persons. We are grateful to Sigurd Christensen, Craig Brandt, Michelle Bell, and John Fackenthal for their work in identi%@, locating, and acquiring data for use in this assessment. We also thank all of the ER personnel who responded to requests for data and provided input and support. We thank the following for providing us with their data and aiding in it's interpretation: George Southworth, Mark Peterson, Walter Hill, Rich Stevens, Chuck Hadden, Pat Ryon, Christy Anderson, Robert Brewer, Dick Halbrook, Chris Welsh, and Jim Evans. Brent Ziegler and John Paul Van Stone provided technical support. All maps were produced by Robert Washington-Allen. Finally, this report has benefitted from the reviews of Glenn Suter and Tom Ashwood. xv i EXECUTIVE SUMMARYHistorically, ecological risk assessment at CERCLA sites [such as the Oak Ridge Reservation (OW)], has focused on species that may be definitively associated with a Contaminated area or source operable unit. This is necessary to identify areas where risk is sufficiently high to warrant remediation. Consequently the species that are generally considered are those with home ranges small enough such that multiple individuals or a distinct population can be expected to reside within the boundaries of the contaminated site. This approach is adequate for sites with single, discrete areas of contamination that only provide habitat for species with limited spatial (e.g., small home range) requirements. This approach is not adequate however for large sites with multiple, spatially separated contaminated areas that provide habitat for wide-ranging wildlife species. Because wide-ranging wildlife species may travel between and use multiple contaminate...

Risks to aerial insectivores (e.g., rough‐winged swallows, little brown bats, and endangered gray bats) were assessed for the remedial investigation of the Clinch River/Poplar Creek (CR/PC) system. Adult mayflies and sediment were collected from three locations and analyzed for contaminants. Sediment‐to‐mayfly contaminant uptake factors were generated from these data and used to estimate contaminant concentrations in mayflies from 13 additional locations. Contaminants of potential ecological concern (COPECs) were identified by comparing exposure estimates generated using point estimates of parameter values to NOAELs. To incorporate the variation in exposure parameters and to provide a better estimate of the potential exposure, the exposure model was recalculated using Monte Carlo methods. The potential for adverse effects was estimated based on the comparison of exposure distribution and the LOAEL. The results of this assessment suggested that population‐level effects to rough‐winged swallows and little brown bats are considered unlikely. However, because gray bats are endangered, effects on individuals may be significant from foraging in limited subreaches of the CR/PC system. This assessment illustrates the advantage of an iterative approach to ecological risk assessments, using fewer conservative assumptions and more realistic modeling of exposure.

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RECEIVEDProgram. This work was performed under work breakdown structure 1.4.12.2.3.4 (activity data sheet 8304, "Technical Integration"). Publication of this document meets an activity data sheet milestone of September 13, 1996. This document provides the Environmental Restoration Program with a preliminary evaluation ofthe ecological risks that contaminants on the Oak Ridge Reservation present to selected wide-ranging species. These results will aid in the understanding of the magnitude of ecological risks to populations at larger spatial scales and will assist in the prioritization of source operable units for investigation and remediation.iii . CONTENTS 5-30The number of potentially exposed red fox focused on species that may be definitively associated with a contaminated area or source operable unit. This is necessary to identify areas where risk is sufficiently high to warrant remediation. Consequently the species that are generally considered are those with home ranges small enough such that multiple individuals or a distinct population can be expected to reside within the boundaries of the contaminated site. This approach is adequate for sites with single, discrete areas of contamination that only provide habitat for species with limited spatial (i.e., small home range) requirements. This approach is not adequate however for large sites with multiple, spatially separated contaminated areas that provide habitat for wide-ranging wildlife species. Because wide-ranging wildlife species may travel between and use multiple contaminated sites, they may be exposed to and be at risk from contaminants from multiple locations. Use (and therefore exposure and risk) of a particular contaminated site by wide-ranging species will be dependant upon the amount of suitable habitat available at that site. Therefore to adequately evaluate risks to wide-ranging species at the ORR-wide scale, the use of multiple contaminated sites must be weighted by the amount of suitable habitat on operable units (OUs). Highly contaminated OUs that provide little habitat are unlikely to be significant contributors to ORR-scale contaminant-associated risk. Conversely, moderately contaminated sites that contain considerable habitat may significantly contribute to ORR-scale contaminant-associated risk.In spring of 1994, a series of meetings were held among the Federal Facilities Agreement parties to develop an approach and plan for assessing risks to wide-ranging species that could not be adequately addressed at the source OU level. The results ofthese discussions are presented in the ORR epological risk assessment strategy document (Suter et al. 1994a). This report is based on this document and presents the preliminary assessment of ecological risks to wide-ranging species from contaminants on the ORR.The reservation-wide ecological risk assessment is intended to serve several purposes, including identifying (1) which endpoints are significantly at risk, (2) which contaminants are responsible for this risk, and (3) which OUs significantly ...