Meeting Notes Summary
River Corridor Baseline Risk Assessment
100 Area and 300 Area Component
Human Health Risk Assessment Introduction
July 19, 2006
WA Dept of Ecology Conference Room
Weiss: Neptune was just hired and is starting the process of preparing the risk assessment report.
Last weeks workshop did not include Human Health Risk Assessment due to scheduling
conflicts. Ralph Perona will be working with Neptune.
Perona: quick bio sketch of self – 10 years with Neptune, before he was with Golder Associates
where he was introduced to Hanford work, including qualitative risk assessments for 100 Area
Operable Units.
Thomson – went over agenda and dates to talk about approach for risk assessments, general
schedule for risk assessment
Faulk –why isn’t there a fish ingestion pathway shown in the conceptual site model (CSM) for
the rural residential scenario? Make sure we are consistent with past agreements in what we are
doing.
Blumenkranz – The Waste Treatment Plant (WTP) pre-operational risk assessment CSM
includes fish ingestion
Gadbois – asked about ambient outdoor air exposure pathway in the CSM
Perona – inhalation of ambient air is included in the dust inhalation pathway (which is based on
contaminants on surface soil) and is captured in dust resuspension. Inhalation of gas phase
contaminants would be captured in the indoor environment
Morgans - no volatile contaminants on site, so EPA’s Johnson and Ettinger VOC intrusion model
has not been employed to date.
Perona – the CSM shows an indoor air exposure pathway for gas-phase contaminants because
such contaminants were identified as potentially of concern in the site models of some reactor
areas.
Morgans – Was Perona provided the scenarios for the 100-B/C and 100/300 Areas as approved
by EPA? Need to be consistent. Need to be peer-reviewed scenarios.
Perona – The 100-B/C Pilot report, and the 2004 report “Exposure Scenario for CTUIR
Traditional Subsistence Lifeways”, were used as the main source of information for the land use
scenarios shown in the draft CSM. Noted that the CSM is still in draft form and this meeting
was one of the venues for obtaining information to refine it. S Weiss agreed to forward to
Perona copies of the final peer-reviewed scenarios.
Gadbois - Use the peer reviewed scenarios and the Umatilla (CTUIR) scenario. Use the
measured groundwater contaminant concentrations in conjunction with groundwater
concentrations predicted based on modeling from 100-300 Area soil sources.
Faulk - Flow diagram of project logic requested with more specifics of what we are going to
accomplish when. Include information like this in the meetings
DOE – Include the RAGS step number corresponding to the task/topic at a given point in the
discussion.
Harper – When do we decide on COCs? Barb wants to be able to see what COCs are being
assessed at each waste site.
Ryti – At this point there are no COCs excluded; we are looking at the entire analytical suites.
The COC selection process will be discussed at upcoming meetings.
Morgans – Consider prioritizing easy data bases like CVP data to make them available sooner
than January 2007.
Harper – The 100-300 RCBRA project timeline shows data summary to be essentially completed
by September, so wonders why data will not be made available until Jan – wants to take the data
and run their own data analysis. Will CVP data be available sooner?
Thomson – we want to make sure that all the data are correct (complete QA process) before
releasing them so that changes won’t be necessary at a later date.
Faulk - CVP data is available in HEIS. There may be some errors in it, but it is accessible to all.
Faulk—did we get all the CVP/RSVPs? Some of the later ones had organics. WCH replied that
all the CVP/RSVP data were downloaded as of December 2005. Dennis recognized that the
organics would be contained in sites closed out before that date, so it would be OK.
Ryti – N&C will work internally with WCH to discuss priorities about early release of some data
sets
DOE – Is CTUIR doing their own risk assessment?
Harper/Morgans – The risk assessment calculations will be independently validated. However,
the scenarios and input parameters will be consistent with the peer-reviewed scenarios and CSM.
Faulk & Gadbois - Drinking water consumption with contaminants need to be included in the
rural residential scenario. Was not included previously as the GW was already over the
threshold levels.
Perona - The measured concentrations of contaminants in GW will be used in the risk
assessments, as shown on the CSM.
Ryti – Definition of exposure pathways to be largely complete for the next meeting, hopefully
we will have agreements after the next meeting
Faulk – B/C Pilot – lost interest in that project when it was taken over by the 100/300 Area so
didn’t do a full review of it – would like to get agreements before using too much from that
document, or at least flag whatever is taken from the 100-B/C pilot so it can be evaluated.
Perona – What was taken from the B/C Pilot with respect to land use scenarios and exposure
pathways is reflected in the draft CSM.
Thomson – The draft CSM does not reflect an intention to abandon any agreements. We
recognize that there are things that can be improved
Harper – what is the work plan for the human health risk assessment
Thomson – The 100/300 Area work plan is still the relevant reference document.
Morgans – We used the EPA peer review from last March to fill the holes in the land use
scenarios.
Harper – exposure point concentrations (EPCs) – when will they be available?
Thomson – The sampling data will be available in January but EPCs may not be available until
later in the process
Ryti- How we do the data reduction will be part of next month’s meeting and will be part of the
web-based interface.
Harper – wants to help structure the web-based interface.
Thomson – how do you want to use it and what are the important parameters for you. Provide
information to Neptune of what you want.
Perona – Any additional comments/suggestions on the CSM figure?
Harper – What is the 15 cm cut-off, how is it different form the 15-foot cutoff for the shallow
zones in the CVPs?
Perona – The MIS sample depth was 15 cm. How to normalize these types of soil data (e.g., two
depth profiles and representing different areas) will be one of the main challenges in developing
EPCs.
Faulk – When we write the final proposed plan, how do we integrate all of the results coming out
of the risk assessment into decisions on what is the right cleanup levels? We will know if the
current cleanup standards are protective, but not know what cleanup criteria might be needed for
more restrictive scenarios.
Gadbois – This risk assessment is not so much about establishing cleanup levels, but to
determine whether the current criteria in the Interim RODs are adequately protective.
Perona – How the analytical results from the various sample media are combined to represent
EPCs over the different spatial scales implied by the exposure pathways described in the CSM is
the primary technical challenge of this assessment
Gadbois – What is the appropriate scale for grouping the data for the decisions that need to be
made—on a point, waste site, operable unit, NPL, or larger scale?.
Harper – A 3D risk map would depict the spatial scale of how large of areas are above the
thresholds.
Faulk – Emphasis will be on the RME assumptions for combining data.
Perona – How we use the environmental data we have. He envisions that the risk assessment
results will not just rely on mathematics, rather, the qualification and interpretation of the
information will be key. By employing both best-estimate and RME assumptions in the
exposure assessment the risk assessment results will capture a range of possible risks.
Gadbois – Presenting the uncertainties in a numeric range as Ralph described is also the
approach desired by EPA
DOE – DOE needs to ensure that there’s continuity among the risk assessments
Harper – Moses said there are differences.
Faulk – There should be differences because the land is different from one area to the next
Dave Blumencranz – presented the WTP scenario. Said that they are relying primarily on EPA’s
Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities for
developing their assessment.
Gadbois – Said that MIS sampling approach may miss hot-spots
WCH – We collected 5 MIS samples at each site and can calculate statistics with that
information. We also have discrete soil data from the CVPs and from the 100/300 Area
sampling to identify more localized areas of elevated concentrations.
Stanfill – If the current conditions are used to establish cleanup levels and the conditions change,
the cleanup decisions and risk assessment are worthless
Price – Just as with other Superfund cleanups, we have to use as a working assumption that
neighboring sites will achieve their cleanup goals. We have to assume that clean up will happen
in the 200 Area. Also noted that the 5 year ROD reviews specified by EPA provide an
opportunity to evaluate the protectiveness of the remedy under changing circumstances
Fluor (Doug Sherwood) – Most contaminants are decreasing at the river, but some (Tc-99 and U)
will get higher over time.
Attendance List
NAME
AFFILIATION
David Blumenkranz
BNI/WTP
Barbara Harper
CTUIR
Jamie Zeisloft
DOE/RL
Cheryl Whalen
Ecology
John Price
Ecology
Alicia Boyd
EPA
Dennis Faulk
EPA
Larry Gadbois
EPA
Tom Fogwell
FH
Steve Airhart
Freestone
Ralph Perona
Neptune
Randy Ryti (via phone)
Neptune
John Stanfill
NPT
Stan Sobczyk
NPT
Donna Morgans
Oregon DOE
Doug Sherwood
Rivers Edge Environmental
Jill Thomson
WCH
Larry Hulstrom
WCH
Shanna Muns
WCH
Steve Weiss
WCH
Rose George-Elisondo
Yakama Nation