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

Annual Site Environmental Report
Sampling for heavy rain event settleable solids took place in January and December 2009.
Radionuclide concentrations for alpha, beta, and 137 Cs were higher at the downstream location, WCK 1.0,
than those observed at upstream locations.
5.6 Groundwater Protection Program
As in years past, groundwater monitoring at ORNL was conducted under two sampling programs in
2009: DOE Environmental Management (EM) monitoring and DOE Office of Science (OS) surveillance
monitoring. The EM groundwater monitoring program was performed by BJC. The OS groundwater
monitoring surveillance program was conducted by UT-Battelle.
Results from the 2009 surveillance monitoring effort at exit pathway monitoring points indicate a
continued decrease in trend in concentrations of radionuclides such as 3 H, total radioactive strontium, and
gross beta activity at WOC Area Discharge wells. Where comparisons could be performed, upper
tolerance limits estimated for metals such as iron, manganese, and aluminum are within range or below
those upper tolerance limits estimated for groundwater in similar bedrock environments at ORNL. Where
these metals are present, it is likely that they are sorbed onto suspended solids in the groundwater samples
collected given that groundwater samples are not filtered prior to analysis. Overall, 2009 contaminant
concentrations in groundwater observed in other watershed or sub-watershed discharge areas are
consistent with observations described in past ASERs. Similar conclusions can be drawn for 2009 SNS
results. Based on the results of the 2009 monitoring effort, there is no indication that current OS
operations are significantly impacting groundwater at ORNL.
5.6.1 DOE-EM Groundwater Monitoring
Monitoring was performed as part of an ongoing comprehensive CERCLA cleanup effort in Bethel
and Melton Valleys at ORNL, the two administrative watersheds at the ORNL site. Groundwater
monitoring for baseline and trend evaluation in addition to measuring effectiveness of completed
CERCLA remedial actions is conducted by the Water Resources Restoration Program (WRRP). The
WRRP has been managed by BJC for the DOE-EM program since its inception and is the vehicle for the
EM program to carry out the monitoring requirements outlined in CERCLA decision documents. The
results of CERCLA monitoring for the ORR for fiscal year 2009, including the monitoring at ORNL, are
evaluated and reported in the 2010 Remediation Effectiveness Report for the U.S. Department of Energy
Oak Ridge Reservation, Oak Ridge, Tennessee (DOE 2010) as required by the Federal Facilities
Agreement for the ORR. The monitoring results and remedy effectiveness evaluations for Bethel and
Melton Valley are reported in Sections 2 and 3, respectively, in the 2010 Remediation Effectiveness
Report.
The WRRP also conducts groundwater monitoring at SWSA 6 and submits the required annual
groundwater monitoring report to TDEC in response to RCRA Permit.
Groundwater monitoring conducted by the EM program at ORNL includes routine sampling and
analysis of groundwater from 27 wells in Bethel Valley. In Melton Valley, where CERCLA remedial
actions were completed in 2006 for the extensive waste management areas, the groundwater monitoring
program includes monitoring groundwater levels in 80 wells to evaluate the effectiveness of hydrologic
isolation of buried waste units. Additionally, groundwater is sampled and analyzed for a wide range of
general chemical and contaminant parameters in 46 wells within the interior portion of the closed waste
management area.
Exit pathway groundwater monitoring conducted by the EM program includes sampling at six
multiport monitoring wells in western Melton Valley (wells 4537, 4538, 4539, 4540, 4541, 4542) and
1 multiport well (4579) in western Bethel Valley.
Oak Ridge National Laboratory 5-73