Oak Ridge Reservation: Exposure Evaluation Work Group

PExposure Evaluation Work Group

March 21, 2005 - Meeting Minutes

Attendance

ORRHES Members attending:
Tony Malinauskas (Chair), Peggy Adkins, Kowetha Davidson, David Johnson, Pete Malmquist, and Charles Washington

Public Members attending:
Lynne Roberson (phone)

ATSDR Staff attending:
Loretta Bush (phone), Jack Hanley, Trent LeCoultre, and Bill Taylor

DOE Staff attending:
Tim Joseph

The Oak Ridger Staff attending:
Ellen Rogers

TA Consulting, Inc. (contractor):
Amy Adkins

ERG Contractors attending:
Liz Bertelsen

Purpose

Tony Malinauskas called the meeting to order at 5:30 p.m. The purpose of the meeting was for Lieutenant (LT) Trent LeCoultre with the Agency for Toxic Substances and Disease Registry (ATSDR) to present information pertaining to ATSDR's Public Health Assessment (PHA) that will evaluate potential exposures to contaminated off-site groundwater from the Oak Ridge Reservation (ORR).

Tony Malinauskas asked for comments on the meeting minutes from February 14, 2005. No comments were noted and the minutes were approved.

ATSDR's Evaluation of Potential Exposures to Contaminated Off-Site Groundwater from the ORR

Presenter: LT Trent LeCoultre, ATSDR

LT Trent LeCoultre explained that the upcoming PHA would evaluate potential exposures to contaminated off-site groundwater from the reservation to the ORR community. Through PowerPoint slides, LT LeCoultre provided detailed information about the PHA, the work conducted thus far, the findings to date, specific community concerns related to this topic, and other aspects of the PHA.

LT Trent LeCoultre stated that the document is an evaluation of the potential for exposure of the community to contaminated groundwater outside of the ORR boundary. He explained that the document was not a) a site wide characterization of on-site groundwater contamination, b) a report on the effectiveness of prescribed groundwater remedies, and c) an evaluation of exposures to contaminated surface water or sediment (even if this contamination is caused by contaminated groundwater).

LT Trent LeCoultre explained that a separate groundwater PHA was conducted in response to community concerns and because the Tennessee Department of Health (TDOH) did not specifically and independently address groundwater in its Reports of the Oak Ridge Dose Reconstruction. LT LeCoultre presented specific community concerns (detailed below) that had been extracted from the ORR Community Health Concerns Database. He intended to address all of these concerns in the document.

• Is the groundwater helping to contribute to kidney cancer?
• Past exposures to arsenic from groundwater may have resulted in high levels of arsenic in my body.
• Groundwater flows from the Y-12 Plant to Scarboro.
• What effect do the solid waste storage areas (SWSAs) have on groundwater?
• Concern that communities that share a limestone slab with a burial ground or dumping ground might have contaminated groundwater.

LT Trent LeCoultre detailed the hydrogeology at the ORR. LT LeCoultre explained that the ORR is in the Valley and Ridge Province, which is characterized by a southwest trending series of valleys and ridges that are a result of crustal folding and vaulting. He noted that differential weathering occurs and described East Tennessee as a depositional environment (sedimentary rocks), which includes sandstones, siltstones, shales, limestones, and dolomites. He also showed the EEWG a geologic map of the ORR Area, which indicated the ORR boundary, the City of Oak Ridge boundary, the main facilities (X-10, K-25, and Y-12) at the ORR, and other features of the reservation area.

LT Trent LeCoultre discussed geologic formations related to the ORR and the surrounding area. He noted that the Oak Ridge National Laboratory (ORNL, formerly referred to as X-10) and the East Tennessee Technology Park (ETTP, formerly known as K-25) were built on the Chickamauga Group formation. He described this formation as an aquitard (aquitard definition: an underground geological formation that is slightly permeable and yields inappreciable amounts of water when compared to an aquifer), which is a flow-limiting strata (strata definition: the layers or beds found in sedimentary rock). LT LeCoultre explained that the Knox Group is the most important aquifer formation in East Tennessee. In this formation, groundwater occurs in joints and fractures and springs are common.

LT Trent LeCoultre said that the Maynardville Limestone aquifer formation was originally included in the Knox Group, but explained that it is now part of the Conasauga Group. He stated that off-site contamination from Y-12 occurs in this formation, which would be the "most important" formation to talk about during the presentation. Except for the Maynardville Limestone, the Conasauga Group was an aquitard with a flow-limiting strata. This group contains the largest waste management areas at the ORR (i.e., Bear Creek Valley and Melton Valley). LT LeCoultre noted that groundwater in this group is shallow and has short flow paths to surface water.

LT Trent LeCoultre presented a slide that depicted the interaction between groundwater and surface water. He explained that "gaining streams" receive water from the groundwater system, whereas "losing streams" lose water to the groundwater system. He noted that most of the ORR streams and rivers are gaining streams, while some reaches of Bear Creek are losing streams. LT LeCoultre stated that most often streams on ORR are gaining and that losing streams are less common.

LT Trent LeCoultre presented a figure to show the time frame for groundwater flow. He also discussed groundwater movement at the ORR and noted the following:

• Groundwater occurs in the unconsolidated zone, where bedrock is typically very near the surface.
• Groundwater primarily occurs in cracks and fissures in the bedrock.
• Fractures decrease significantly at depth.
• Flow paths to surface water are very short.
• As much as 95% of the shallow groundwater ends up as surface water.
• Seeps, springs, and diffuse discharge to streams.
• The Clinch River is a major topographic feature that prohibits migration of groundwater off site.

LT Trent LeCoultre said that he organized watershed groupings based on similar hydrogeology and nature of ORR activities. The groups consisted of the a) ETTP Watershed, b) Bethel Valley and Melton Valley Watersheds, and c) Bear Creek Valley, Upper East Fork Poplar Creek (UEFPC), and Chestnut Ridge Watersheds. He also showed the EEWG a map that detailed the locations of the ORR watersheds.

LT Trent LeCoultre explained that the ETTP Watershed, which was constructed on the Chickamauga Group, included the K-25 site and the former S-50 site. The water in this watershed occurs in cracks and fissures that decrease with depth. Most of the watershed's groundwater discharges to surface water (i.e., Mitchell Branch, Poplar Creek, and Clinch River). LT LeCoultre said that several commingling volatile organic compound (VOC) plumes exist in the watershed as a result of contributing sources that include the K-27 building, K-1070 C/D burial grounds, and K-1401 area. He noted that dye tracing has identified exit point locations where monitoring now occurs regularly. He stated that the plumes show either stable or declining VOC concentrations. In addition, Mitchell Branch is a discharge point for shallow groundwater.

For the ETTP Watershed, LT Trent LeCoultre presented a map of the plumes and then summarized the following:

• Groundwater contamination is a result of several commingling VOC plumes.
• Plumes occur in the shallow groundwater.
• Mitchell Branch serves as a discharge point for shallow groundwater.
• There is no evidence that site-related contaminants have migrated beyond the ORR boundaries in groundwater.
• Contamination has moved off site in surface water.

LT Trent LeCoultre next discussed the Bethel Valley and Melton Valley Watersheds, which include ORNL, and are separated by Haw Ridge (a Rome formation). He stated that the Chickamauga Group underlies Bethel Valley and the Conasauga Group underlies Melton Valley. He said that these watersheds have a very shallow water table with short flow paths to surface water. Bethel Valley contains the main operations of ORNL and has over 150 sites that have been identified for environmental restoration. He described the Corehole 8 strontium 90 (Sr 90) plume located in Bethel Valley. The source of the plume was a W-1A tank in the North Tank Farm that was commissioned in 1951 to receive low-level liquid waste (LLLW) from on-site buildings. Under a National Pollutant Discharge Elimination System (NPDES) permit, contaminated groundwater is removed, treated, and discharged to First Creek.

LT Trent LeCoultre described groundwater contamination in Melton Valley. He explained that experimenting with hydrofracture injection wells began in two separate areas (hydrofracture wells HF-1 and HF-2) in the 1950s. LT LeCoultre stated that this process revealed that the Pumpkin Valley Shale could effectively and safely contain the contamination. There were 24 observation and monitoring wells installed at each area. According to LT LeCoultre, successful operations continued until 1982 at the Old Hydrofracture Facility (OHF) and the New Hydrofracture Facility (NHF). He noted that because of U.S. Environmental Protection Agency (EPA) underground injection control regulations, operations at the injection wells were discontinued.

LT Trent LeCoultre added that the U.S. Army Environmental Center's (USAEC) Southern Regional Burial Ground for ORNL and more than 50 other facilities are located in Melton Valley. Major burial grounds include SWSAs 4, 5, and 6. The main contaminants of concern (COCs) are cesium 137, cobalt 60, tritium, and strontium 90. Further, SWSA 4 Seep areas and SWSA 5 Seeps C and D are the principal release areas. The primary component of contaminant movement is via shallow groundwater release to surface water.

After presenting a map to show the areas with detected COCs, LT Trent LeCoultre summarized some key points related to the Bethel Valley and Melton Valley Watersheds:

• There is a very shallow water table with short flow paths to surface water.
• Under NPDES permit, the Corehole 8 plume is intercepted, treated, and released to surface water.
• Hydrofracture process is expected to effectively and safely contain contamination.
• Groundwater discharges to surface water (i.e., White Oak Creek and Melton Branch).
• Contamination moves off site in surface water.

LT Trent LeCoultre provided information on the Bear Creek Valley and UEFPC Watersheds, which include the Y-12 Plant. The watersheds are bound to the north by Pine Ridge and to the south by Chestnut Ridge. According to LT LeCoultre, the Y-12 complex was built entirely on the Conasauga Group. He said that the Maynardville Limestone aquifer formation is the primary pathway for contaminants to migrate from Y-12. He noted that there is also a groundwater divide between the watersheds.

Regarding groundwater contamination in Bear Creek Valley, LT Trent LeCoultre mentioned the Boneyard/Burnyard, the S-2 Site, and the Bear Creek Burial Grounds. He noted that uranium, nitrate, manganese, and many VOCs are present in the Maynardville Limestone and detections have exceeded the maximum contaminant levels (MCLs). He explained that Bear Creek has both gaining and losing reaches. He added that remedial activities have significantly reduced contaminant concentrations.

LT Trent LeCoultre explained that groundwater contamination in the UEFPC Watershed occurs beneath the entire watershed. He noted that carbon tetrachloride in the East End VOC (EEVOC) plume—the only confirmed off-site groundwater plume—is the primary off-site groundwater contaminant. He added that dense nonaqueous phase liquids (DNAPLs) exist on site and that groundwater contamination occurs in the Maynardville Limestone. LT LeCoultre detailed how groundwater in this watershed flows along strike, goes east beyond the ORR boundary, and flows into Union Valley. LT LeCoultre said that groundwater from adjacent formations flows toward the Maynardville Limestone. He stated that depth to the water table is between 1 and 7 feet below ground, and that groundwater in the Maynardville Limestone occurs as deep as 500 feet. He also noted that groundwater serves as the base flow for UEFPC and Scarboro Creek.

LT Trent LeCoultre showed a map of the areas where contaminants have been detected. He noted that no residential wells exist within 2 miles of the areas. He said that one community concern had asked whether groundwater flowed from the Y-12 Plant to Scarboro. LT LeCoultre said that the answer to this question is "no." He explained that a moratorium exists so that residential wells cannot be installed in the contaminated areas.

LT Trent LeCoultre presented the following summary points for Bear Creek Valley and UEFPC:

• Groundwater contamination occurs in the Maynardville Limestone.
• Groundwater flows along strike beyond the ORR boundary into Union Valley.
• Groundwater surfaces via seeps, springs, and diffuse discharge to streams.
• Site-related groundwater contamination has not been detected beyond Scarboro Creek.
• The nearest residential well is approximately 2.25 miles away.

LT Trent LeCoultre showed a slide with the sources used to obtain off-site groundwater data. Sources (listed below) included the Oak Ridge Environmental Information System (OREIS) Database and Tennessee Department of Environment and Conservation (TDEC) reports, which contain data from more than 2,150 on-site and 120 off-site monitoring locations.

• ORNL Groundwater Monitoring Data (1991-2004)
• ORNL Bethel Valley Watershed Remedial Investigation (RI) (1997)
• ORNL White Oak Creek Watershed RI (1996)
• Y-12 Upper East Fork Poplar Creek RI (1997)
• Y-12 Groundwater Protection Program (Ongoing)
• ORR Integrated Water Quality Program (1998)
• ORR Water Resources Restoration Program (Ongoing)
• ORR Remediation Effectiveness Reports (2000-2005)
• K-25, K-1070-A Burial Ground – Brashears Creek
• Lower East Fork Poplar Creek Operable Unit
• Atomic City Auto Parts Site Characterization
• TDEC Environmental Monitoring Reports (through 2003)

LT Trent LeCoultre presented maps by facility (i.e., K-25, X-10, and Y-12) of monitoring locations for which he has received data. He reminded the EEWG that he is only interested in "what is going off site."

LT Trent LeCoultre also discussed residential wells. He said that TDEC began a sampling program for residential wells in 1996. There were 71 residential wells identified southwest of and within 2 miles of the reservation. LT LeCoultre said that a 1996 house-to-house survey revealed no anecdotal problems with well water. As a result of analytical results, TDEC has reported, "no discernible impact [to residential wells] from the activities of DOE [U.S. Department of Energy] on the ORR."

LT Trent LeCoultre presented residential well data to indicate contaminants that have been detected above ATSDR's comparison values (CVs) in residential wells. He noted that the maximum concentrations of boron, chromium, lead, and manganese were detected above CVs in residential wells southwest of K-25. In residential wells southwest of X-10, data indicate that maximum values of iron, lead, manganese, and nitrate exceeded ATSDR's CVs. No radionuclides, however, were detected above MCLs in residential wells. In addition, LT LeCoultre stated that none of these contaminants "appear to be site related."

LT Trent LeCoultre also provided information on off-site monitoring wells. He noted that 43 chemical contaminants and 13 radionuclides were detected off site at levels that exceeded ATSDR's CVs (in at least 10% of the samples in monitoring wells). In off-site monitoring wells near K-25, no groundwater contaminants were detected. LT LeCoultre stated that five contaminants were detected in off-site monitoring wells near X-10, and 41 chemical contaminants and 13 radionuclides were detected in off-site monitoring wells near Y-12.

In summary, LT Trent LeCoultre noted the following:

• Groundwater at the ORR is shallow with short flow paths to surface water.
• Water bodies surrounding the site and subsurface geology prevent most off-site migration of contaminant plumes.
• The only site-related off-site groundwater contamination is from Y-12 in Union Valley.
• No site-related contaminants have been detected in residential wells above ATSDR's CVs.
• Exposure to the off-site EEVOC plume is unlikely because of zoning regulations, administrative controls, and the absence of residential wells.

Discussion

Tony Malinauskas asked about the time frame that would be considered in the PHA. LT Trent LeCoultre replied that all data available from TDEC and OREIS would be evaluated for the document. Jack Hanley added that the PHA would primarily evaluate exposures from the late 1980s or early 1990s to the present. Pete Malmquist asked about the definition being used to determine what constitutes surface water and groundwater. LT Trent LeCoultre responded that he defined groundwater as "anything subsurface." He said that groundwater discharged to streams was considered surface water. Charles Washington noted that this was "peculiar in Oak Ridge" because groundwater becomes surface water and surface water becomes groundwater.

Jack Hanley asked if the Clinch River was a gaining stream. LT Trent LeCoultre said that Mr. Hanley was correct.

Following LT Trent LeCoultre's statement that plumes related to ETTP groundwater contamination have shown either stable or declining VOC concentrations, Tony Malinauskas asked if the flow of groundwater had increased and if there was a larger volume of groundwater. Based on "general trends," LT LeCoultre did not believe that there was an increase in the flow or volume of groundwater.

Jack Hanley asked if some of the contamination sources had been removed. Tim Joseph replied that a lot of capping had occurred, which reduced the percolation of contamination.

Bill Taylor asked if the contamination from the ETTP Watershed eventually reaches the Clinch River via groundwater. LT Trent LeCoultre stated that Dr. Taylor was correct. Charles Washington added that contamination has been detected "as far away as Chattanooga."

Charles Washington asked if there were contaminant-specific remedies or one remedy for all COCs in Melton Valley. LT Trent LeCoultre was unsure, but he knew that remedies were in place. Jack Hanley explained that LT LeCoultre would not be evaluating on-site remedial activities for the PHA. LT LeCoultre clarified that he was asking, "Is it off site? And if so, is anyone exposed to it?"

Tony Malinauskas asked where the SWSAs were located. LT Trent LeCoultre pointed to the areas on a map. Dr. Malinauskas asked if they were beyond the ridge, and LT LeCoultre said that this was correct.

Bill Taylor asked if the contamination in Bear Creek Valley flows into the Clinch River. LT Trent LeCoultre replied that it eventually does flow into the river.

Charles Washington asked which types of formations on the ORR might move across the reservation because they allow for "easy flow." LT Trent LeCoultre said that the Maynardville Limestone allows for "easy flow." He added that the Knox Group was an aquifer formation with typically "good springs."

Tim Joseph asked if the nearest residential well to the Beer Creek Valley and UEFPC Watersheds was 2.25 miles away from the plume. LT Trent LeCoultre said that Dr. Joseph was correct. David Johnson asked the depth of the well. LT LeCoultre was unsure, but said that he would research this to find an answer.

During LT Trent LeCoultre's discussion on TDEC's residential well sampling program in 1996, Charles Washington noted that this was "late in time compared to when [the facilities were] releasing quantities in the past."

Tim Joseph asked how many of the contaminants detected above CVs in residential wells were naturally-occurring. LT Trent LeCoultre responded, "Many are naturally-occurring." Charles Washington said that these were "not necessarily [naturally-occurring] in this area and not at that level." LT LeCoultre explained that these were raw data and that the information represented only a "preliminary analysis."

Charles Washington asked about the form of chromium in the residential well data table. LT Trent LeCoultre was unsure if this was chromium III or VI and he was unable to determine where the chromium originated.

Bill Taylor asked if remedial activities would be discussed in the PHA. LT Trent LeCoultre replied that the most significant remedial actions would be discussed.

Charles Washington was "surprised" that toluene and benzene were not detected. LT Trent LeCoultre said that benzene was identified. Pete Malmquist asked if mercury was detected. LT LeCoultre said that mercury had been detected, and noted that he had not listed all of the contaminants. He added that contaminants such as mercury and arsenic are not highly mobile, but that VOCs move the quickest. Dr. Malmquist thought that methylmercury was mobile. LT LeCoultre said that mercury becomes more mobile when it is "methylated" by bacteria. This typically happens in surface water or in sediment, not at depth in groundwater. Bill Taylor believed that this was detected in much smaller concentrations than other forms of mercury.

Tim Joseph suggested looking at the contaminants to see if a wide variability existed. If there was not a wide variability, then it would be "obvious" the contaminants were "not from the site." He also thought LT Trent LeCoultre could look at the well data and determine the number of wells where particular contaminants were detected. Dr. Joseph said that if many wells had a particular contaminant, then you could say it was "indicative." If a contaminant was only detected in two or three wells, however, then it would not be natural.

Tony Malinauskas asked where the monitoring location was on the plume. LT Trent LeCoultre responded that monitoring locations exist within the plume and at the front of the plume beyond the extent of the contamination. Jack Hanley asked about the recent request for the remedial investigation/feasibility study (RI/FS) on the plume. LT LeCoultre said that Union Valley Interim Record of Decision (ROD) had put administrative controls in place to prevent exposure to contaminated groundwater.

Peggy Adkins asked if LT Trent LeCoultre would share the list of 43 contaminants. LT LeCoultre said that these would be shared. Ms. Adkins knew that no data existed from the 1950 and 1960s. She asked if there was a way to estimate exposures during this time period, prior to safety measures and when the ORR was fully operating. LT LeCoultre did not believe that this type of analyses could be conducted "with any level of confidence." He added that he is using maximum concentrations that occurred in 1997 and 1998.

Peggy Adkins stated that having many outcroppings is an indication of more porosity and also allows for more flow. LT Trent LeCoultre said that Ms. Adkins was correct, but that this was relatively shallow. He said that cracks and other characteristics limit the predictability of groundwater flow.

Peggy Adkins asked if LT Trent LeCoultre would address the issue of bacterial contamination. Jack Hanley said that the county had programs to address bacteria in wells, but that he was not familiar enough with these programs to provide more information at this time.

Peggy Adkins said that she had lived in the Crestwood Subdivision in a cove that was fed by Rose Valley Lake. She showed the group where her old neighborhood was on a map. She said that if you extended Gallagher Road about ¼ mile, then it would have been located there. She said that she had "lots of mercury, nickel, cadmium, some strontium, and arsenic" in her body at "extremely high levels." She noted, "Another woman living across the street had the same symptoms, but won't be tested." She said, "all women had diseases" throughout her cove and the "men got Alzheimer's." She stated that these diseases were "unrelated in families" and that the "well water is the only thing [they have] in common." She added that her property had been sold and the county had since closed the well.

Tim Joseph asked if anyone had conducted sampling, and noted that the health department will test wells. LT Trent LeCoultre believed it would be unlikely that groundwater from the site could have traveled to these wells. Peggy Adkins said that a geologist had told her that she was on the "same slab with where stuff was dumped." Ms. Adkins stated that she had "seen an actual map with texture" and that this made "sense when you see it even with topography."

Tim Joseph said that it is "not unusual to see wells that are completely contaminated." He said that you "have to know what's in there." Charles Washington said that this was in a cove where things are "not moving."

Jack Hanley asked if Peggy Adkins knew the name of the geologist, but she did not. She said she could go back to the state geologist to find out. Mr. Hanley suggested that Ms. Adkins find out his name and ATSDR could contact him.

Tony Malinauskas adjourned the meeting at 7:00 pm.