Science and Technology for Environmental Cleanup at Hanford (2001) / Chapter Skim
Currently Skimming:
8 Columbia River Technical Element
8 Columbia River Technical Element
Pages 108-124
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 108... ...
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.
|
From page 109... ...
, the second occurs during Hanford Site operations (19441980) , and the third includes post-Hanford operations and river restoration (1980-present)
|
From page 110... ...
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.
|
From page 111... ...
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.
|
From page 112... ...
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.
|
From page 113... ...
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.
|
From page 114... ...
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)
|
From page 115... ...
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.
|
From page 116... ...
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)
|
From page 117... ...
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.
|
From page 118... ...
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.
|
From page 119... ...
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.
|
From page 120... ...
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
|
From page 121... ...
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)
|
From page 122... ...
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.
|
From page 123... ...
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.
|
From page 124... ...
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.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.