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8
Columbia River Technical Element
This chapter provides a review and assessment of Integration
Project science and technology (S&T) under the Columbia River
Technical Element. This technical element supports studies to improve
understanding of the river environment, particularly as it relates to
contaminant inputs, transport, and impacts on biological systems. The
Columbia River is likely to be the main pathway for contaminant transfer
to humans because local populations rely on the river to various degrees
for recreation, irrigation and drinking water, and other sustenance. Thus,
to the extent that contaminants are present or are likely to be introduced
into the Columbia River, understanding their fate and transport in the river
system is important for protecting present and future human populations.
COLUMBIA RIVER HISTORY'
The Columbia River drains an area of 259,000 square miles
(39,000 square miles in Canada). It is the fifth largest river in the United
States in terms of area and the third largest in terms of discharge. There
are more than 400 dams in the watershed that provide more than 21
million kilowatts of electrical power generating capacity including 11
dams on the Columbia River, 7 of which are located upstream from the
Hanford Site and four downstream (Figure 8.1~. Damming of the
Columbia was initiated in 1938 with the completion of the Bonneville Dam
and ended in 1973 with the completion of the Mica Dam in Canada.
The Hanford Reach extends from the Priest Rapids Dam
upstream of the Hanford Site to the head of Lake Wallula, which was
created by the McNary Dam (Figure 8.2~. It is the last free-flowing stretch
of the Columbia River, although discharge through the reach has been
altered by upstream controls. The historical variation in river stage
through the reach of up to 27 feet has been reduced to 9-10 feet by dam
construction.
The information in this section was taken from several reports and papers,
including Rickard and Watson, 1985; Minshall, 1988; Rickard and Gray, 1995;
Zorpette, 1996; Williams et al., 1998; the Center for Columbia River History
[http://www.ccrh.org/river/history.htm]; and the Pacific Northwest National
Laboratory [http://www.pnl.gov/env/surface-water_surveillance.htm].
108
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Columbia River Technical Element
109
From a historical perspective, the environmental characteristics of
Hanford Reach can be divided into three periods, all of which are related
to differing land use activities. The first period is pre-dam construction
(prior to 1930), the second occurs during Hanford Site operations (1944-
1980), and the third includes post-Hanford operations and river
restoration (1980-present).
If.'
a
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=
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. _ 1
__
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ID
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r
Fatima Ri~re~r
USE
CctJllmbia River
350
345
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BY
of..
u.~srn~^
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~a
s~ch~n~t~
0 5 10
Mi~s
Length
Figure 8.1 Plan view of the Columbia River in the vicinity of the Hanford
Site. Numbers denote miles above the river mouth. SOURCE:
BHI, 1999, Figure E-5.
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Science and Technology for Environmental Cleanup
During the pre-dam construction period, the area around the
Hanford Site was occupied for at least 10,000 years by several Indian
groups. The first Euro-American exploration in the area was by Lewis and
Clark in 1805. Indian groups ceded their lands to the government at the
Treaty Council of 1855, leading to the expansion of Euro-American
settlements.
By 1860, a ferry was operating across the Columbia River at
White Bluffs, one of the first permanent settlements in the Hanford area
on the east bank of the Columbia River. General population increases
with the influx of gold miners at about that same time encouraged
ranching development across the Columbia Plateau. Steamboats were
also operating on the Columbia River up to White Bluffs.
400
300
200
-
E 100
.Q
`1~) 200
100
1 _
1944
Bonneville Or
1971 to Present
I:
Open Channel Flow
,
,
,_
,~
\~rs
A
Priest
Rapids
Hanford ~ '
Reach ~
McNary _f9~ 1959
John Day 1~953
The Dallas ~
Bonnev~l~ IT '56 Dam~nstruction
0 100 200 300 400
Miles Above Mouth of Rwer
Figure 8.2 Top: Profile of the Columbia River channel bed in 1944.
Boffom: Profile of the river channel at present. Dates on the figure
indicate dam completion. NOTE: msl = mean sea level.
SOURCE: BHI, 1999, Figure E-4.
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Columbia River Technical Element
111
Arid conditions in the region prevented the spread of dryland
farming, and agriculture was limited until irrigation canals were
constructed in the late 1 880s and further expanded in the early 1 900s.
Railroad construction led to the founding of Pasco and Kennewick in the
early 1880s, but difficult weather and soil conditions frustrated the
development of the area through the early 1 930s. Irrigation projects
bringing water to the north and east of the Hanford Site were completed in
the 1 950s and continue to support agricultural activity to the present.
Although few water quality data are available prior to 1930, the
lack of development and limited use of the river suggest that water quality
was good. The natural flow variability limited riparian vegetation and
contributed to varied habitat conditions supporting more than 44 species
of fish in the Hanford Reach.
With initiation of construction on the Hanford Site, small
settlements were relocated and site worker populations were as high as
50,000 in the ~ 940s. Water quality records for discharges to the Columbia
River become available with the advent of operations at the site.
Beginning in 1944, operating reactors released heated water,
radionuclides, and corrosion-inhibiting chemicals directly to the river (see
Chapter 2~. The work force of 50,000 generated domestic waste that was
also discharged to the ground and river.
Between 1951 and 1965, the operating reactors released a
maximum of 24,000 megawatts of heat and 10,000-12,000 curies of
radionuclides to the river each day. It is estimated that 1 10 million curies
of radiation were released to the river between 1944 and 1971 (Rickard
and Watson, 1985; see Chapter 2~. Most of the released radionuclides
had short half-lives, and releases included activation products associated
with natural elements present in the cooling waters. These discharges
introduced short-lived radionuclides such as phosphorus-32 and zinc-65
into river biota. Longer-lived radionuclides, now buried in river sediment,
include cobalt-60, strontium-90, cesium-137, uranium-238, and plutonium-
238, 239, and 240. In addition to releases from the Hanford Site, irrigation
return water from agricultural activity to the east of the site entered the
Columbia River (as both surface and groundwater) near Ringold and
Richland.
Between 1964 and 1971, the single-pass plutonium production
reactors were phased out (see Table 2.1 ) and chemical and radionuclide
releases to the Columbia River essentially ceased. The N-Reactor
continued to release heat, but little radioactivity. It was shut down in 1987.
In the restoration phase that followed the shutdown of all
production reactors, environmental surveillance work has found that
radionuclides in blots in the Hanford Reach are the same as in blots from
upstream reference reaches of the Columbia River where no radiation
was released. The major environmental concern for river ecosystems is
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Science and Technology for Environmental Cleanup
the regulation of flow from upstream dams. The lack of high-stage
variability has altered riparian vegetation, and the presence of artificial
water-stage controls has led to destruction of spawning reads (Figure 8.3)
and stranding of fish, because stage variations now occur over hours
rather than days to weeks as in the past (Williams et al., 1998~. The major
continuing concerns about water quality in the Hanford Reach include the
addition of agricultural chemicals, discharge of effluents from upstream
industrial development, and the continuing contribution of low levels of
contaminants from the Hanford Site through groundwater discharges into
the river.
Figure 8.3 Photo of spawning reads in the Hanford reach in a slough
immediately downstream of the 1 00-F Reactor area. Downstream
is to the left. SOURCE: Zack Carter, Boeing Computer Services.
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Columbia River Technical Element
SCOPE OF THE COLUMBIA RIVER TECHNICAL ELEMENT
The Columbia River Technical Element comprises five S&T
activities with 21 individual projects (Table 8.1~:
1. Detailed conceptual model. This activity includes three
projects (CR-1 to CR-3) intended to develop a conceptual model that
accounts for contaminant fate and transport in the river system.
2. Information management. This activity includes four projects
(CR-4 to CR-7) intended to develop a system to gather, screen, and
manage data for the river assessment and also to populate this system
with available data and information from both the Department of Energy
(DOE) and external sources.
3. Characterization. This activity includes four projects (CR-8 to
CR-1 1 ) intended to identify habitats, species abundance, and distributions
and to determine biological transfer functions2 for contaminants-species
combinations of interest.
4. Groundwater-river interface study. This activity comprises six
projects (CR-12 to CR-17) intended to develop and test conceptual and
numerical models for groundwater and contaminant discharges to the
Columbia River.
5. Fate and transport. This activity comprises four projects (CR-
18 to CR-21 ) intended to develop and test conceptual and numerical
models for fate and transport of contaminants in the river system.
113
The schedule and budget for the Columbia River Technical
Element are given in Table 8.1. Projects are planned to run from fiscal
year 1999 through fiscal year 2004, and work was under way in four of
the five activities during the committee's review. The total planned funding
for this technical element is $8.17 million, but the Integration Project plans
to obtain at least half of this funding from Hanford's core programs, and
some of the future funding may be provided by external sources such as
DOE Headquarters.
2A biological transfer function is a measure of the movement of a contaminant
between food-chain levels in an ecosystem- for example, the transfer between
microscopic algae growing on rock surfaces in the river and the aquatic insects
that graze on those algae.
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Science and Technology for Environmental Cleanup
TABLE 8.1 Summary of S&T Activities and Planned S&T Projects Under the Columbia
River Technical Element
S&T Activity SAT Project Objectives Project Hanford EMSP
Projects Duration Funding Funding
Planned (fiscal (thousand (thousand
years) dollars) dollars)
Detailed 3 Develop a detailed 1999-2002 225a b o
conceptual conceptual model of
model the river system that
includes critical
components and
processes and
identifies important
links
Information 4 Develop an information 2001-2002 325b 0
management management system
to gather, screen, and
manage data and
information for river
assessment and
populate this system
with available data and
information
Charactenzation 4 Identify habitats, 2000-2004 3,520a c 0
species abundance,
and distributions and
determine biological
transfer functions for
contaminant-species
combinations of
interest
Groundwater- 6 Obtain an improved 1999-2004 2,000a ~ 0
river Interface understanding of, and
study develop and test
conceptual and
numerical models for,
contaminant discharge
from groundwater to
the Columbia River
Fate and 4 Develop and test 1999-2004 2,100a 0
transport conceptual and
numerical models for
contaminant fate and
transport in the river
system
NOTE: EMSP = Environmental Management Science Program
aAdditional funding for this work is being provided through the System Assessment Capability (see Chapter 4).
The funding shown in the table will be provided by the Characterization of Systems Project (see Chapter 3).
The funding shown in the table will be provided by the River Monitoring Project (see Chapter 3).
dThe Integration Project intends to seek funding from national S&T programs (e.g., from DOE Headquarters)
for some of this wor c.
SOURCE: DOE, 2000a, Figure 4-1, Table 5-1.
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Columbia River Technical Element
115
EVALUATION OF WORK PLANNED UNDER THE COLUMBIA RIVER
TECHNICAL ELEMENT
The committee's assessment of this technical element is based
primarily on a review of the Integration Project Roadmap (DOE, 2000a)
and planning documents (DOE, 1 999e; DOE, 2000g) provided by the
Integration Project and secondarily on information received at committee
meetings. The latter includes a demonstration of a numerical model of the
groundwater-river interface, discussions with several Integration Project
investigators, and (for one committee member) a tour of the Hanford
Reach.
The committee provides assessments below of each of the S&T
activities shown in Table 8.1. Three of the assessments are structured
using the five evaluation questions that were first introduced in Chapter
6. There was not enough information available to use these questions to
structure the remaining two assessments, so the committee instead
provides brief commentaries.
Conceptual Model Development
The S&T projects under this activity are focused on the
development of a river conceptual model. This model will provide a
quantitative description of the processes that occur in various
components of the river system, including the riparian zone and
associated blots along the river, aquatic biota, groundwater-river
interface, river bottom and sediments, river water column, and users of
river resources. The model for this element is termed "conceptual"
because it is focused on identifying important processes and links among
the various model components listed above, and it will connect processes
in the Hanford Reach with important river controls both upstream and
downstream of the site. Once the important processes are identified, a
numerical model that can simulate these processes will be developed.
The conceptual and numerical models are being developed in
three modules: (1 ) the zone of groundwater-river interaction; (2)
hydrodynamic, sediment, and contaminant transport in the river; and (3)
biological transport. The Integration Project plans to use the model results
for site and downstream risk and impact assessments. The model is
designed to estimate concentrations for four classes of radionuclides and
two chemicals. The System Assessment Capability (SAC) will be the
primary user of this model (DOE, 2000g).
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Science and Technology for Environmental Cleanup
Can the objectives of the planned work be achieved?
The Columbia River conceptual model as described in the SAC
documents (e.g., BHI, 1999) is intended to account for important
contaminant transport processes in the Columbia River. The inclusion in
this model of regional-scale river processes is, in the committee's view,
essential to obtain useful impact assessments, because conditions in the
river at the Hanford Site are controlled by upstream dam operations as
well as water quality management activities in the watershed.
Based on the committee's understanding, this conceptual model
can probably support SAC Rev. 0 needs (see Chapter 4~. The conceptual
model may have limited resolution, however, because it models the river
as a series of segments, each characterized by a set of average model
parameters. The sizes of these segments were unspecified in the
materials reviewed by the committee. The general structure of the
conceptual mode! appears to the committee to be robust and may support
expansion as needed to meet other, possibly as-yet-undefined, objectives
in the future.
Does the planned work represent new science ?
The approach being taken is best described as the application of
current science and modeling techniques, rather than new science. Many
components of the model have already been developed and/or applied to
the Columbia River. On the other hand, there are not, to the committee's
knowledge, many models that integrate the complex linkages among the
major components (i.e., groundwater, river hydrodynamics, biological
receptors) of large river systems. In the committee's opinion, this
conceptual modeling effort at Hanford, if successful, is likely to contribute
to the development of capabilities that can be applied to other large rivers.
Can the planned work have an impact on cleanup decisions at the
Hanford Site?
Although the river is a critical and visible element of the cleanup
program, the Hanford Reach has already shown marked recovery from
past contaminant discharges (see Chapter 2 and the discussion
elsewhere in the chapter) because of its high capacity for dilution and
transport. The committee expects that this conceptual model will confirm
the Columbia River's capacity for self-maintenance and may support the
prioritization of resources to those areas of the Hanford Reach subject to
greatest contaminant loadings- for example, spatially restricted zones of
contaminated groundwater discharge to the river bed. However, the
present level of resolution of the model will likely be inadequate to support
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Columbia Giver Technical Element
il
117
mpact assessments or decision making in these spatially restricted
zones.
Does the planned work acldress the important issues?
The planned work is designed to develop a conceptual model that
will support site decision making. The model may assist in impact analysis
and contribute to more effective management of contaminants at the
Hanford Site. As noted above however, the level of resolution in the
model will limit its utility in addressing site-specific contaminant issues in
the Columbia River.
Are there other concerns, comments, or suggestions that should be
considered by the Integration Project in executing the planned work?
The committee has two general concerns about this S&T activity:
the first is model resolution or scale, and the second is model validation.
The concern related to model resolution involves the range of scales over
which the model must operate. This issue of scale is addressed, in part, in
discussions provided elsewhere in this report (see, for example, Chapter
6 and Appendix C). As noted previously, the plan to model the river as a
series of segments, the lengths of which were undocumented in the
materials reviewed by the committee, probably will preclude the use of
this model to assess impacts from specific contaminant discharge zones
in the bed of the Columbia River.
The concern about model validation is also related to scale.
Temporal and spatial mode! scales may range over 13 orders of
magnitude. The selection of a single or even a limited number of scales
for model analysis will affect model validation efforts. For example, the
scale of the data to be used in model calibration and validation may not
exactly match the scale of resolution of the model itself, particularly when
historic data, which were not collected specifically to meet model needs,
are used. Further, the inherent variability of large river ecosystems will
complicate normal model validation efforts. Although the concerns about
scale and validation raised here are relevant for any model development
and application effort, the time scales associated with contaminant effect
and the spatial scales associated with contaminant movement and effect
suggest that these issues will be of particular importance to Columbia
River modeling.
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Science and Technology for Environmental Cleanup
Information Management
Environmental data have been collected at the Hanford Site since
it became operational in 1944. Additional monitoring programs have been
put into place in succeeding decades in response to regulatory
requirements, and these continue to generate large amounts of data.
Recognizing the extent and complexity of existing data resources, the
objective of the four S&T projects (CRY to CR-7) under this activity is to
develop an information management system to "screen, manage, and
disperse" data and information from both inside and outside Hanford. The
information management system will be cleveloped by September 2001
and will be updated regularly as additional site data are collected.
The committee recognizes the need for efficient and effective
data management at the Hanford Site. There may be S&T needs
associated with the development and application of new information
technologies, but these were not made clear in the documentation
reviewed by the committee. Therefore, given the apparent lack of an S&T
context for this work, information management development would seem
to be better handled in programs other than the Integration Project S&T
program. With completion of the planned information management
system later this year, additional S&T work does not appear to be needed
on this issue.
Characterization
The four characterization projects (CR-8 to CR-1 1 ) under this
activity involve fate and transport model parameterization and
environmental data collection to support fate and transport analysis for
future SAC revisions (see Chapter 4~. The projects under this activity will
elucidate the transfer of contaminants through organisms and the
identification of critical habitats. Because SAC revisions will require
increasingly complex and detailed data, the characterization projects must
meet future as well as present SAC data needs.
Although details of future SAC revisions are not available at this
time, the committee expects that model revisions will involve reductions in
model scales (both spatial and temporal) to obtain increases in mode!
resolution. The improved resolution may allow the models to be used to
assess impacts at more spatially restricted river scales than is possible
with the current generation of models.
In general, the planned projects appear to the committee, at least
on the surface, to be designed to respond to expected data needs.
However, the available project descriptions are inadequate to allow
detailed evaluations of individual projects. It is critical that these projects
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Columbia River Technical Element
119
be integrated effectively with those from the other technical elements to
ensure that the data collected meet the "characterization" needs of those
projects or provide sufficient information to support model calibration and
validation.
In the committee's view, an important S&T need under the
characterization activity is to define and quantify impact"thresholds," that
is, points at which small changes in environmental conditions can result in
major changes to species habitat, abundance, or health. Similarly, the
committee believes that the characterization activity should provide the
Integration Project with techniques or characterization protocols that could
support the development of new tools for impact assessment. The
committee did not see this outcome explicitly identified, but
documentation did suggest that improved impact assessment would be
an outcome of this activity.
Considering the scope of future management needs in the
Hanford Reach, and the lack of full understanding of ecosystem structure
and function in large river systems, the committee believes that new
monitoring tools and techniques may be required to obtain the needed
characterization data. The development of new large river and ecosystem
monitoring tools" specifically to provide information about organism
distribution and ecology in the river channel and the interaction between
the river and the riparian zone is viewed by the committee as an
important S&T gap in the current program.
Although there are numerous biological monitoring tools available
(Schaeffer and Herricks, 1993), these tools have limited application to
ecosystem dynamics (Schaeffer et al., 1988~. This is particularly true for
large river systems, the theoretical ecological foundations for which are
based on research in small streams. Similarly, the interactions between
rivers and riparian/floodplain ecosystems is an important element of river
ecology (Ward, 1989) that is poorly understood for large rivers. It should
be recognized that ecology is entering a new era of analysis supported by
advancing technology (Thompson et al., 2001), which will allow
researchers to address how biological and physical processes interact
over multiple spatial and temporal scales. The committee believes that
the S&T program should be oriented to advancing the capability for
impact assessment in the Columbia River using the most modern
monitoring and analysis tools available.
The committee therefore recommends that the S&T program
support the development of advanced biological monitoring
approaches for the Columbia River. Additional details on this
recommendation are provided in the last section of this chapter.
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Groundwater-River Interface
The groundwater/river interface activity includes six projects (CR-
12 to CR-17) that are designed to model the interactions between
groundwater and the Columbia River. The projects are focused on
developing models and filling data needs by conducting field and
complementary laboratory experiments. The planned investigations
include the elucidation of dynamics of flow direction; contaminant
attenuation, decay, and transformation; biological processes; transport
rates; and preferential pathways associated with contaminant discharge
from aquifers to the Columbia River. The models developed in these
projects will provide the primary support for contaminant fate and
transport analysis and eventual prediction of impacts. Planned activities
include numerical model development and simulations to develop impact
predictions. Based on DOE (20009), it appears that the first model
development will be completed in fiscal year 2002.
Can the objectives of the planned work be achieved?
The groundwater-river interface activity is designed to support
fate and effects analyses for the Columbia River. Although the
documentation suggests a 2002 start date for this activity, as noted
above, a model that integrates groundwater flow with river stage changes
was demonstrated to the committee during one of its meetings, which
suggests that progress already is being made on this activity.
Some of the objectives of the planned work in project CR-13
depend on the completion of several field and laboratory investigations
that have not yet begun. Planning documents reviewed by the committee
suggest that these investigations are planned to be completed in
approximately six months. This schedule is overly optimistic given the
complexity of the planned work. Further, the projects that are supposed to
compare predictive and observational data against impact criteria (CR-15
to CR-17) do not have clear plans or objectives. Without clearly defined
objectives, it is not possible to evaluate project merit or to predict
success.
Does the planned work represent new science?
The numerical model to be developed for the groundwater-river
interface is unusual because of the river size and the rapid flow
alterations due to upstream dam releases, which produces rapid changes
in river stage, changes in hydrostatic regimes in the river banks, and
corresponding changes in groundwater movement. This model will be
able to build on the groundwater and vadose-zone modeling under way at
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Columbia River Technical Element
the Hanford Site in that these models will provide good estimates of the
rate of delivery and expected concentration of contaminants to the river
bank area. This work has the potential to produce new insights, and the
modeling approaches developed are potentially applicable to other large
rivers.
Can the planned work have an impact on cleanup decisions at the
Hanford Site?
121
This model may allow the Integration Project to describe more
effectively the interactions between groundwater and the Columbia River,
which can contribute to understanding contaminant impacts on the river
system. This model could lead to improvements in prioritization of cleanup
activities based on future hazards to the Columbia River, if the model
resolution issues raised previously are addressed.
Does the planned work address the important issues?
Given the fact that groundwater discharges along the Hanford
Reach are on the order of 104-102 cubic feet per second and the average
river discharge through the reach is on the order of 105 cubic feet per
second, it is unlikely that groundwater discharges will substantially affect
the Columbia River at the scale of the Hanford Reach this is true even
for low-flow conditions, because river discharge is maintained by releases
from upstream dams.
This said, however, it is likely that groundwater contamination will
enter the Columbia River in the future in spatially limited areas, as is
observed today, creating locally high concentrations in or near habitats of
important organisms (e.g., salmon) in the river ecosystem. Contaminant
concentrations that affect river organisms at spatially restricted scales
may not produce significant impacts on the Columbia River ecosystem as
a whole. Nevertheless, it will be important to identify groundwater inflow
locations to assess whether any effects on critical species or habitats
should to be minimized. The proposed modeling activity could contribute
to the identification of both critical habitats and species that may be
affected by groundwater-related contaminants entering the river in the
future.
Fate and Transport
The fate and transport activity comprises four projects (CR-18 to
CR-21 ) that involve the development of a quantitative model for
hydrologic, sediment, and contaminant transport. The activity will also
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Science and Technology for Environmental Cleanup
include laboratory-based testing that will be concluded in 2002.
Descriptions of these projects provided in DOE (2000g) suggest a focus
on tracking contaminant transport for only a limited list of contaminants
(described as nutrient and nonnutrient metals) in a limited selection of
species (one fish and one aquatic invertebrate species). The
contaminants and species to be studied will be identified during the
projects.
Can the objectives of the planned work be achieved ?
Hydrologic models have been developed already by several
organizations, and these models are being modified for application to the
Columbia River. Therefore, the committee believes it is likely that the
hydrologic modeling objectives of these projects will be achieved.
The fate and transport activity also includes modeling of sediment
and biological transport, as well as general contaminant transport in the
Columbia River. The entire set of models will be evaluated against
measurements and monitoring data from the Columbia River. The
committee believes that it is likely that models that capture general
process characteristics can be developed to meet the objectives of this
activity. The committee believes it unlikely, however, that models
incorporating even a moderate level of complexity can be developed in
the time frame proposed.
Does the planned work address the important issues?
Contaminant transport through the Columbia River system is an
important issue, which must be addressed through both modeling and
data collection. An important use of models is to identify the critical data
needed for site decisions. The committee believes that this modeling
exercise, if executed well, could benefit existing river monitoring programs
by contributing to a better review of data utility.
This modeling exercise could also contribute to a better
understanding of the possible implications of small-scale, or localized,
contamination for broader ecosystem conditions in the river, if the models
have the appropriate spatial and temporal scales. For example, if this
modeling identifies transport pathways for contaminants or the
propagation of effects from localized contaminant zones in the river, then
the planned work may provide critically needed information to guide future
research and data collection. The committee believes that these types of
simulation models are best used to guide research and are much less
useful for prediction of impacts.
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Columbia River Technical Element
Are there other concerns, comments, or suggestions that should be
considered by the Integration Project in executing the planned work?
123
The major concern associated with the fate and transport of
contaminants from the Hanford Site is the potential for contaminants to
produce harm for thousands of years. In predicting fate and transport, the
models must account for long-lived contaminants. Further, the models
must consider the effect of extremely rare events, such as catastrophic
floods, on fate and transport. Comments on these issues are provided in
Chapter 4; see also Chapter 9.
SUMMARY AND DISCUSSION
The committee believes that the S&T activities planned for the
Columbia River Technical Element have the potential to contribute to a
better understanding of the Columbia River, the interactions between
groundwater flows from the Hanford Site and the river, and the potential
effects of contamination from the Hanford Site on the river ecosystem.
However, in many cases the documentation was insufficient to allow the
committee to judge whether this potential is likely to be realized.
The committee believes that the activities in the Columbia River
Technical Element should be viewed in the broader context of the
Columbia River watershed and the Hanford Reach. As noted at the
beginning of this chapter, the Hanford Reach (Figure 8.2) is the last free-
flowing stretch of the Columbia River. As the last remnant of a once-vast
and important resource, the Hanford Reach certainly deserves attention
from the Hanford Site's cleanup program although it may well be that
the impacts of site contaminants on the reach are insignificant, and
therefore the river may not be the most important factor in site cleanup
· -
c eclslons.
The Columbia River has undergone many changes over the last
100 years. It has been dammed, its flow has been altered, and its major
fishery has been compromised. At the same time, the Columbia River has
been subject to high thermal, raclionuclide, and other contaminant loads
from the Hanford Site, with little apparent residual effects (e.g., PNNL,
1999; see also the discussion of Columbia River history elsewhere in this
chapter). The Hanford Reach has been flushed by large volumes of water
in the decades following the cessation of plutonium production operations
at the site, and the Columbia River ecosystem has recovered through
natural processes. Today, the Hanford Reach is one of the most valued
and ecologically important stretches of the Columbia River.
In light of the importance of the Columbia River, the committee
recognizes the need for an integrated site and river model but cautions
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against overdependence on modeling, where scale and validation issues
can compromise model utility. The committee sees a clear need for
information management, but recognizes that information management
will operate in support of other cleanup activities, rather than leading
them. Similarly, characterization activities, the groundwater-river interface
analysis, and fate and transport modeling are viewed by the committee as
supporting, rather than leading, activities of the Integration Project.
The committee has identified aclditional S&T needs in the
Columbia River Technical Element. In particular, the committee finds a
need for advanced modeling that will integrate results over the scales of
analysis and the biological effects present in the Hanford Reach-
Columbia River watershed. The committee supports better
characterization of the environmental setting and better fate and transport
information for contaminants and ecosystems. The committee recognizes,
however, that limited resources may well be allocated to characterization
of, or modeling contaminant transport from, areas of contaminant
concentration such as the 200 Area. In other words, the committee would
not place a priority in the S&T program for work in the Columbia River
Technical Element given S&T needs of other technical elements.
As noted elsewhere in this chapter, the committee recommends
that the S&T program support the development of advanced
biological monitoring approaches for the Columbia River. The
committee believes that there is a critical need to develop new
technologies for ecosystem assessment that will complement and expand
the current radionuclide and chemical monitoring capabilities. There is an
extensive literature on biological monitoring that provides a clear
indication of the value of using blots as sensitive indicators, for example,
of water quality (Rosenberg and Resh, 1993; Kerans and Karr, 1994~.
Advanced biological monitoring procedures, which include a wide range
of genetic, biochemical, organism, community, and ecosystem metrics,
some measured in real time, represent the state of the art in assessing
ecosystem quality and condition.
Finally, the committee suggests that protection of the Columbia
River may benefit from a monitoring program directed to the zones of
effect in the groundwater-river interface. Biological monitoring of these
areas will give more power to detect contaminant impacts on the biota
relative to reach-scale assessments. Early determination of impact, or a
finding of no impact, in the Columbia River would provide critical
information for cleanup decisions at the Hanford Site.
Representative terms from entire chapter:
technical element
