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

Annual Site Environmental Report
Monitoring results for 2009 indicated that mercury concentrations at all instream locations were
below the Tennessee water quality criterion for recreational use, 51 ng/L (parts per trillion), with a few
stream reaches showing higher mercury concentrations and/or fluxes than the rest (Fig. 5.28 and
Fig. 5.30). These areas of interest included Outfall 211 and the area downstream from that outfall in
White Oak Creek; a particular reach of Fifth Creek; and White Oak Creek downstream of its confluence
with Fifth Creek (Fig. 5.29 and Fig. 5.31).
Methylmercury values were typically less than 1% of the total mercury concentrations and fluxes
monitored in the same locations. Dissolved methylmercury was only detected at a few of the monitoring
locations; overall much less methylmercury than total mercury, both in dissolved and undissolved
analyses, was detected.
For 2010, WQPP mercury investigative efforts will focus on one or more of the areas of interest that
were identified in the 2009 monitoring. A subset of the 2009 characterization-monitoring protocol will
also be conducted in 2010, to maintain ongoing data on the presence of mercury in the White Oak Creek
watershed.
5.5.6 Ambient Dry and Wet Weather Monitoring
In 2009, the ORNL WQPP included an objective to characterize water quality at some of the same
instream locations where biological communities (fish and benthic macroinvertebrates) are monitored.
These locations, where both biological and water quality data were collected, are referred to in the WQPP
as integration points. Monitoring sites included seven integration points within or downstream of
industrialized areas and four water quality reference locations upstream of the majority of process and
stormwater discharges from those industrialized areas (see Fig. 5.32). The purpose of generating a
Fig. 5.32. Locations of ambient water quality monitoring integration points and
reference locations at ORNL.
Oak Ridge National Laboratory 5-59