DOE/ORO/2327 Oak Ridge Reservation Annual Site Environmental ...

Oak Ridge Reservation
Fig. 5.38. Taxonomic richness (top) and richness of the pollutionintolerant
taxa (bottom) of the benthic macroinvertebrate communities in
White Oak Creek, April sampling periods, 1987−2009. WCK = White Oak
Creek kilometer; WBK = Walker Branch kilometer; EPT = Ephemeroptera,
Plecoptera, and Trichoptera; WBK 1.0 = reference site.
In 2009, the focus of PCB monitoring at ORNL under the BMAP was on the identification of the
stream reaches in the White Oak Creek watershed where PCB sources are likely to contribute to
bioaccumulation in fish. Key integration points within the watershed were identified and monitoring
results from impacted sites were compared to reference sites in each of the streams on the main ORNL
campus and Melton Valley to assess bioaccumulation potential.
The mobility of the fish populations used in traditional bioaccumulation monitoring studies precludes
the possibility of source identification. Therefore, the source identification task involved the use of semipermeable
membrane devices (SPMDs) to assess the chronic, low-level discharges of PCBs at critical
sites on the reservation. SPMDs are essentially oil-filled plastic sleeves in which PCBs are soluble.
5-66 Oak Ridge National Laboratory