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Regulator/Trustee Workshop for 100 Area and 300 Area Component of the RCBRA
March 21, 2007
The workshop convened at 8:30 am with introductions.
1) River Corridor Closeout Process – Jill Thomson (Washington Closure Hanford )
Jill Thomson (WCH) discussed the River Corridor closeout process, and distributed a handout with timescale of remedial actions and RODs.
2) Pore Water and Conductivity – Brett Tiller (Environmental Assessment Services)
Brett Tiller (EAS) discussed pore water and the background of historical trends of surface water flows and conductivity in the Columbia River. River fluctuations on the Hanford Reach vary due to discharges from the hydroelectric dams. Examples of planned fluctuations imposed by the dams include seasonal for runoff, power demands and salmon spawning. Tiller discussed water fluctuations with respect to the “green line.”
Specific conductance was compared to water discharge rates. High discharge rates suppress emergence of groundwater in the Columbia River. Wade Riggsbee (Yakama Nation) added that groundwater emergence is variable and not well understood/complicated (confined vs. unconfined).
Don Steffeck (USFWS) asked about the conductivity sampling – how frequently was pore water
sampled to obtain the appropriate sample volume? Tiller said that it took about 20 sampling events to obtain the necessary volume. In some places, the conductance was rapidly depleted following initial sampling of pore water; therefore the pump rate was reduced.
Barbara Harper (CTUIR) asked about the conductance of pure groundwater versus what was observed in the conductivity sampling. Randy Ryti (Neptune) discussed mixing in terms of groundwater infiltration through a mass/volume of moving water. Jim Hansen (USFWS) asked if the initial pore water samples were influenced by pulling too much surface water into the pore water sample. Brett explained how the pull rates were reduced to allow for reinfiltration of pore water in the horizontal pore water tubes. Beth Rochette (Ecology) asked if the pore water samples were realistic exposure representations or an example of sampling techniques. Ryti explained that the SAP directed to capture the exposure for most hyporheic organisms in the pore water zone (emergence and mixing at 10 cm depth); the intent is was not to sample pure groundwater.
Jay McConnaughey (Yakama Nation) asked how the 10 cm hyporheic zone was defined. He raised the question of Stanford’s article observations of hyporheic organisms living a mile interior from a water source. Jim Markwiese (Neptune) explained that the ecosystem in Stanford’s article is dissimilar to the Columbia River and the hyporheic organisms have less ability to move to reduced pore size. It was mentioned that 10 cm is the average maximum depth
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for Asiatic clams. Paul Shaffer (Oregon Department of Energy) recommended saying that 10 cm was arbitrary and to move on to another topic.
Paul Shaffer asked how the conductivity and pore water samples would be used in analysis understanding that sampling methods differed. Randy Ryti explained that the data were evaluated qualitatively as a spatial and temporal gradient. The year that the RCBRA samples were taken was indicative of average flow conditions over the years. The re-sampling event was indicative of lower flow conditions, therefore the information could be used to address uncertainties of river fluctuation.
Don Steffeck asked about the macroinvertebrate baskets and clam tubes- did they represent worst case or best case with respect to water flow? The clam tubes were deployed and underwent a variety of flows; the rock baskets were nestled in the cobbles to interface with any emergent groundwater.
; Either provide more information to support 10 cm depth or make it clear that this is an
assumed depth for most hyporheic organisms
; Provide information on flow conditions for the near shore aquatic samples to include both
pore water samples and deployed biological samples (rock baskets and clam sleeves)
3) Data Quality – Jenifer Linville (Neptune & Co)
Scott van Verst (WDOH) asked if results included uncertainties. Uncertainties are included where available, but were not used as part of the usability criteria in the data quality analysis. Data from non-RCBRA sources were used “as is.” It was asked if data from other sources were verified to be comparable with the RCBRA data? Data were not verified to be comparable to the RCBRA data, and it is acknowledged that different sample preparations methods may exist between data sources (100-B/C Pilot data was an example).
Data qualifiers were described. A qualifier of “R” indicates the data point was rejected by the laboratory, reviewer, or validator. Not very many data were “R” qualified. The majority of the data were classified as useable. Data that weren’t useable were deemed “RCBRA not useable” and assigned a reason code to indicate why the result was not useable.
Barbara Harper asked about the use of the PQL in the quality evaluation. She described having seen data sets where MDL and PQL and other categories were mixed up and these ended up ruining the whole data set. Randy Ryti explained that in the SAP, a list of analytes/indicator contaminants were compiled, that covered a number of suites. This list gave us a target for what the detection limit numbers were required. These indicator contaminant lists and detection limits were organized into tables by media (water, tissue, etc…). The purpose of the data quality evaluation was to determine if the planning objectives were met.
A handout was distributing listing the detection status of constituents in the RCBRA data set. The PQLs varied by matrix, as stated in Section 2 of the SAP. It was recommended that the handout be changed to describe results by media. It was also reiterated that the results in the
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handout where the value was greater than the PQL were non-detect values. Detected results greater than the PQL were used as detected results.
The handling of non-detect results was discussed. It was noted that 2/3rds of the data are non-detects – it is important how these data are evaluated in the report. It was noted that if the project met the PQLs then non-detects would not be risk drivers. For those cases where the detection limit is greater than the PQL and a benchmark then that should be addressed in the risk assessment uncertainty analyses.
; Clarify data tabulations – are detected or non-detected data being summarized
; Consider how non-detect data are being evaluated in the report
Nature and Extent of Contamination – Randy Ryti (Neptune & Co)
The presentation included plots of key contaminants to understand spatial and temporal trends - Hanford River Mile (HRM), temporal gradients, and across media. Gerry Pollet (Heart of America) asked about the sampling of Aroclors along the Hanford Reach – were the Aroclor
locations sampled selected specifically? Aroclors were examined in the RCBRA data at all locations and also in some existing data sets.
Pam Brown (Hanford Advisory Board) asked why fish weren’t sampled all across the river. Ryti
explained that the data came from a variety of sources and that suites weren’t consistent between all samples/data sources. She asked about high non-detect results and how such a high value could be reported as non-detect. Randy Ryti explained that detection limits varied by data source.
Dan Landeen (Nez Perce) suggested adding a benchmark reference line to the plots (w/media label). Damon Delistraty (Ecology) asked about adding congener analyses to the PCB suite. He criticized that Aroclor analysis was nonspecific.
Dan Landeen asked if there were any clams collected between HRM 20 and 40. Harper suggested coloring data by plume. Paul Shaffer was interested in making a plot to figure out where high concentrations were present. Questions were raised regarding appearance of chromium in multiple media, why was it detected in some media and not in others?
Randy Ryti presented time series data; Don Steffeck asked about how the 100-B/C Pilot’s
analytical/prep method was different from that used by RCBRA. The 100-B/C Pilot Project used a different sample prep/extraction method that entailed total matrix dissolution rather than a leachable extraction – therefore, those data were incongruous with RCBRA results. Those
specific results are rcbra_useable, but not comparable for analyses.
Don Steffeck asked if the upland waste site data is representative of pre- or post-remediation conditions. He also asked if the B/C Pilot data on Slide 60 had the method discrepancy issue. Jim Hansen asked how widespread the use of the total extraction method was - was it used in the statewide background data set? Don Steffeck suggested that the when the benchmarks are
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identified on the charts, that they are comparable with the methods/media (specifically, extraction).
Randy Ryti discussed trends in lead and strontium-90 concentrations. There was an anomalous detection of strontium-90 in plant tissue near Pit 9 (upland reference site, west of 300 Area). Paul Shaffer asked about the depth and Hanford River Mile assignment. There appeared to be a depth assignment issue for some soil samples – very high levels not likely shallow zone.
Barbara Harper asked how much is known about biota tissue types. The level of detail available is documented in the database as biota_media_type and biota_media_tissue in the GiSdT database.
Dan Landeen asked if the same species of plant (and what tissue type) showed elevated U-238? Beth Rochette expressed a concern related to chemical toxicity of uranium – she requested that
we convert isotopic uranium data to total uranium.
Patrick Moran (USGS) asked if risk assessment findings would be incorporated in the PNNL monitoring project. Steve Weiss (WCH) answered that the risk assessment would be provided to PNNL for consideration in planning of future monitoring. Don Steffeck mentioned that biological and abiological measures both track plume behavior and provide evidence for exposure.
; Verify sample depth assignments and other key sample information
; Plot data by locations versus time; it makes it difficult to note trends when many
locations are overlaid on one plot
; Calculate total uranium from isotopic uranium; assess total uranium for its toxicity as a
Representative Concentrations – Tom Stockton (Neptune & Co)
There were several questions regarding distributions (normal, lognormal) and what affects them (physical site characteristics). Patrick Moran asked if the reasonable maximum exposure (RME) is being properly represented such that demonstration of no risk makes further discussion negligible? The calculation of RME as maximum vs. UCL was discussed.
Beth Rochette asked how n<5 is being treated; she recommended defaulting to the maximum or calculated RME, whichever is higher. However, it was noted which is higher depends on the distribution of the data or at least the assumed statistical distribution of the data. Should we make a default assumption for the distribution of all data? Tom Stockton explained that RME calculation is automatic, using decision logic. Barbara Harper suggested when n=5, use the maximum. When reviewing the UCL results presented on slide 86, Paul Schaffer had a concern the UCLs were not calculated properly; he asked that we verify the calculations.
Ralph Perona (Neptune) noted that the automation precludes a point by point assessment. Larry Gadbois (EPA) concluded that we already discussed the data collection and analyses as part of
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the DQO and SAP processes - that we need to analyze the data and move forward. Patrick Moran agreed that where there was not a demonstrated risk, continued discussion is moot.
Harper asked a detailed question about ecological food chain and exposure modeling; she is interested in risk in terms of predicted versus measured. It was explained that the ecological exposure model uses measured data, not modeled. This approach for evaluating ecological risk was agreed to during the DQO process. Human health uses modeling from soil to produce and has the ability to compare to measured data.
; Continue discussions on how UCLs are being calculated and under what circumstances
the maximum value is used as the RME
; Verify that the UCL calculations are correct
Timing of the upcoming meetings was discussed. Patrick Moran suggested meeting on May thth15/16 if it will be a 2-day meeting. July 25 meeting was selected instead of July 18.
Columbia River Component Update – Larry Hulstrom (WCH)
The status of the Columbia River Component (CRC) was discussed. The CRC data summary report was issued in July 2006. Conclusions were presented last year at the Inter-Areas workshop in June and August 2006 (Trustee working and HAB meetings). In February 2007, the Tri-Parties discussed the results of the summary report and requested a data gap analysis. The downstream boundary was also discussed. Downstream boundary recommendations included the Richland drinking water intake or the I-182 bridge. Barbara Harper asked about trustee involvement in the Columbia River Component – DOE upper management told senior trustees
that they would be involved in decision-making, but they have not been involved to date. Larry Hulstrom indicated that DOE wants to set a clear path forward before they solicited input from the NRTC. Current boundaries recommended are Priest Rapids Dam to below McNary Dam. Larry Hulstrom mentioned that the CRC contractor would be using data from GiSdT.
Inter-Areas Update – Jackie Queen (WCH)
The status of the Inter-Areas investigation was discussed, including recent sampling. Comparability of horizontal and vertical pore water data was discussed. Other factors seemed to be more important. Also there is a lot of spatial variation. Confounding factors in the sampling would be recorded and documented. It was also recommended that the recent history of dam discharge and river depth (6-8 hour range prior to sampling) be documented for each sampling event.
100 AND 300 AREA RCBRA RISK ASSESSMENT
MARCH 21, 2007
Name Organization Pam Larsen City of Richland Barbara Harper CTUIR Rico Cruz CTUIR Ted Repasky CTUIR Dana Ward DOE-RL Jamie Zeisloft DOE-RL John Sands DOE-RL Beth Rochette Ecology Damon Delistraty Ecology Larry Gadbois EPA
Gerry Pollet Heart of America Jenifer Linville Neptune & Company Jim Markwiese Neptune & Company Ralph Perona Neptune & Company Randall Ryti Neptune & Company Tom Stockton Neptune & Company Rebecca Arenson NOAA Dan Landeen NPT
Donna Morgans Oregon DOE Paul Shaffer Oregon DOE Jim Hansen USFWS Pat Moran USGS
Scott Van Verst WA DOH Chuck Hedel WCH
Darci Teel WCH
100 AND 300 AREA RCBRA RISK ASSESSMENT
MARCH 21, 2007
Name Organization Jackie Queen WCH
Jill Thomson WCH
Larry Hulstrom WCH
Randy Hermann WCH
Steve Weiss WCH
Charlene Andrade WDFW
Jay McConnaughey Yakama Nation Wade Riggsbee Yakama Nation