Nonradiological water quality data were compiled by the Surface Environmental Surveillance Project and the
USGS during 1994. A number of the parameters measured have no regulatory limits; however, they are
useful as indicators of water quality and/or Hanford-origin contaminants. Potential sources of pollutants not
associated with Hanford include irrigation return water and ground-water seepage associated with extensive
irrigation north and east of the Columbia River.
Figure
5.3.10
shows the Vernita Bridge and the Richland Pumphouse USGS results for 1989 through 1994 for several water
quality parameters with respect to the applicable standards. In accordance with Washington State Water
Quality Standards (Appendix C, Table C.1.), fecal coliform results are presented as annual geometric means
(i.e., the antilogarithm of the arithmetic mean of the logarithms of the individual sample values). Turbidity
and dissolved oxygen results are presented as annual arithmetic means. The complete list of results obtained
through the USGS national water quality network are summarized in Appendix A, Table A.5. The 1994
USGS results were comparable to those reported during the previous 5 years. Applicable standards for a
Class A-designated surface-water body were met. During 1994, there was no indication of any deterioration
of water quality resulting from Hanford operations along the Hanford Reach of the Columbia River.
Results of nonradiological sampling conducted by the Surface Environmental Surveillance Project along cross
sections of the Columbia River at the Vernita Bridge, 100-N Area, 100-F Area, old Hanford Townsite, 300
Area, and the Richland Pumphouse are provided by Bisping (1995). The concentrations of volatile organics,
metals, and anions observed in river water in 1994 were similar to those observed in the past (Dirkes et al.
1993). Volatile organic compounds were not routinely detected; those that were detected in 1994 included
acetone (in one of a total of 94 samples collected) and methylene chloride. Average annual concentrations of
both compounds were higher at the Vernita Bridge than at the Richland Pumphouse. Neither compound
displayed elevated concentrations along the Hanford shoreline of the Columbia River.
Several metals and anions were detected both upstream and downstream of the Hanford Site at levels
comparable to those reported by the USGS as part of their ongoing national water quality monitoring
network. With the exception of magnesium and manganese, whose average quarterly concentrations were
highest at the Richland Pumphouse, no consistent differences were found between average quarterly
contaminant concentrations in the Vernita Bridge and Richland Pumphouse samples. All metal and anion
concentrations in river water were less than primary Washington State and federal Drinking Water Standards
(Appendix C, Table C.3). However, aluminum and iron concentrations in Columbia River water collected
along the Hanford shoreline at the 300 Area exceeded their respective secondary Drinking Water Standards.
Secondary Drinking Water Standards are based on factors other than health effects. Elevated concentrations
of aluminum and iron were also observed in Columbia River springs in the 300 Area during 1994 (see
Riverbank Springs subsection). Other contaminants with elevated concentrations measured near the Hanford
shoreline included manganese in the 300 Area transect and nitrate in the old Hanford Townsite transect. The
highest nitrate concentrations, however, were measured on the Franklin County shoreline and likely resulted
from irrigation returns.
The annual average flow rate of the Columbia River at Priest Rapids Dam was 
(94,400 cfs)
during 1994, similar to that reported in recent years. The monthly average flow rates at Priest Rapids Dam
are shown in Figure
5.3.11
. The peak monthly average flow rate occurred during June ( [151,430 cfs]), and the lowest monthly average flow rate occurred during September ( [60,050 cfs]). Daily average flow rates varied from 1,045 to (36,900 to 180,000 cfs) during 1994.
Columbia River Sediment
In 1994, numerous studies were conducted on various aspects of sediment contamination in the Columbia
River. This section will discuss the results of 1994 sediment surveillance activities. In addition, special
studies or activities in 1994 that are pertinent to the evaluation of Columbia River sediment contamination
will also be discussed.
Sample Collection and Analysis
Samples of Columbia River surface sediments (1-5 cm) were collected at 12 stations from six annual
monitoring sites (shown in Figure 5.3.1 and summarized in Table 5.3.2) during 1994. Monitoring sites
located at McNary and Priest Rapids Dams consisted of a transect with four stations established across the
river at approximately equal distances. At the Hanford Reach sampling locations (White Bluffs Slough,
100-F Slough, Hanford Slough, and Richland Pumphouse), a single near-shore grab sample (Hanford Site
shoreline) was collected. A sample was taken at each sampling point using a Petite Ponar Grab sampler with
a 
opening. Sediment samples were analyzed for gamma emitters (see Appendix F), plutonium-238,
plutonium-239, plutonium-240, strontium-90, uranium-235, -238, and ICP metals (DOE 1994c). The
sampling locations and methods used are discussed in detail in the Environmental Monitoring Plan (DOE
1994c).
Sediment Monitoring Results and Discussion
Sediments in the Columbia River contain low levels of radionuclides and metals of Hanford origin and
radionuclides from nuclear weapons testing fallout (Beasley et al. 1981, Robertson and Fix 1977, Woodruff et
al. 1992, Blanton et al. 1995). Hanford Site-derived pollutants are transported in surface waters in particulate
or dissolved form. In fluvial systems, particulate transport is based on particle size, particle density, and
water velocity. Contaminants associated with minerals are transported and deposited differently than
contaminants associated with organic carbon. Organic carbon content of sediments is associated with the
finer grained size fractions. Thus, areas where water velocity is reduced (slack water) will have a higher
composition of fine-grained sediment and organic carbon content. Sediment grain size and total organic
carbon content varied greatly among sediment monitoring site locations (Blanton et al. 1995). Consequently,
concentrations of contaminants in sediments can vary significantly depending on sediment makeup and
particle size distribution. Therefore, direct comparisons between bulk sediment contaminant concentrations
among monitoring stations at Priest Rapids Dam, the Hanford Reach, and McNary Dam must consider the
effects of grain size and total organic carbon content on sediment contaminant sorption. These factors were
considered in the following discussion of the 1994 sediment monitoring results. The results and discussion
are presented for both individual monitoring sites and regional means. Regional means include the sampling
stations in the Priest Rapids and McNary Dams transects as well as the Hanford Reach stations of White
Bluffs, 100-F Area and Hanford Sloughs, and the Richland Pumphouse. All 1994 data collected for both
radionuclides and chemicals (metals, inorganics) in sediments is reported in Bisping (1995). For more
detailed information on sediment grain size and contaminant associations see Blanton et al. (1995).
In general, radiological analytical results for surface sediment samples collected during 1994 (Appendix A,
Table A.6) were very low or below the minimum detection levels at all sites sampled. Appendix A, Table A.6
summarizes data for 1989 through 1993. The McNary Dam site had the highest concentrations of
radionuclides during 1994. However, no appreciable differences existed between the Priest Rapids Dam
reference site and the Hanford Reach or McNary Dam stations (Figure 5.3.12). Radionuclide concentration
measured during 1994 were similar to those in sediment samples collected during the previous 5 years. The
downriver trend in radionuclide concentration described above was expected based on examination of the
grain size distribution and total organic carbon content of sediment collected from each monitoring site
location (Blanton et al. 1995).
A summary of 1994 metal (and other inorganics) results is provided in Appendix A, Table A.7. All metal
concentrations analyzed were detected above the minimum detection level. In general, mean metal
concentrations along the Hanford Reach and at McNary Dam were not significantly different (based on the
standard error of the mean) than those found at Priest Rapids Dam. (Figure 5.3.13). Mean chromium
concentrations in sediment along the Hanford Reach appeared to be slightly elevated when compared to Priest
Rapids and McNary Dams. A single elevated result at 100-F Slough (100 mg/kg) accounts for the increase in
the mean chemical concentration. Generally, concentrations of metals at monitoring locations support the
grain size and total organic carbon data reported in Blanton et al. 1995.
Review of 1994 Special Studies on Columbia River Sediments
Factors Controlling Sediment Contaminant Sorption
A special sediment monitoring study was conducted in 1994 to investigate the difference in sediment grain size
composition and total organic carbon content at established monitoring sites. The study also determined if
associations exist between sediment contaminant burden, grain size composition and total organic carbon content.
During this study, sediments at the six Columbia River monitoring locations (Figure 5.3.1) were analyzed for grain
size, total organic carbon content, radionuclides, metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls,
and pesticides (Blanton et al. 1995). Sediment grain size and total organic carbon influence contaminant fate and
transport. In general, river sediments with higher total organic carbon and finer grain size distribution can have higher
contaminant burdens than sediments with less total organic carbon and more coarse-grained sediments.
Physicochemical sediment characteristics were found to be highly variable among monitoring sites along the
Columbia River. Again, sediment grain size and total organic carbon content should be considered in interpretations
of sediment monitoring data. Additional detailed information on specific grain size and total organic carbon
characteristics for individual monitoring sites is provided in Blanton et al. (1995).
Figure 5.3.12
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