APPENDIX B: METHODS FOR FIELD INVESTIGATIONS
Monitoring Sediment Moisture and Temperature in Eagle River Flats and
Resampling of Field-Contaminated Sites
mark. The two-person party moved to each loca-
FIELD STUDY TO MONITOR SEDIMENT
tion to be surveyed, and the triple prism on the
MOISTURE AND TEMPERATURE
prism rod was placed on the ground at each site. To
achieve uniformity in surveying elevations, the tip
Selection of sites
Sites were selected along an eastwest transect
of the prism rod was placed inside a bucket, which
through Area C, extending from a permanently
was in a tub placed on the ground surface. This
flooded zone to the east through the intermittent
provided a uniform bearing surface for the rod tip,
ponded area to the west, across the mudflat zone to
keeping it from sinking down into the soft mud.
the levee adjacent to the Eagle River (Fig. 15). Sites
The horizontal angle and vertical distance from the
were selected based on elevation. The elevation
total station to the prism were then measured and
change along this transect was on the order of 50
recorded. Based on the horizontal angle and verti-
cm, and sites were chosen to represent this gradi-
cal distance from the control point, the height of
ent. Sites were not be located in gullies. First, a sur-
the total station above the control point, and the
vey of the elevation change between the perma-
height of the prism above the survey point, a set of
nently flooded site and the river levee was con-
UTM coordinates and an elevation for the survey
ducted by measuring the elevation at 16 points
point were calculated.
along the transect. Then study sites were selected
Only uncontaminated sites were selected. The
such that one site (site 1) was permanently flooded,
sediment at each site was tested for the presence of
four sites (sites 25) were in the intermittent pond,
P4 particles using a field screening procedure
three sites were on mudflat (sites 68), and two
(Walsh et al., in prep). This method involves
sites were on the river levee (sites 910) (Fig. 16).
spreading a thin layer of sediment across the bot-
Surveying was performed using a Leitz SET4C
tom of an 8-in.-diameter aluminum pie pan and
electronic total station and a triple reflective prism
heating the pan on a propane camp stove. The
mounted on a 1.45-m-tall prism rod. One person
presence of P4 particles is detected by localized ar-
ran the total station, while two people occupied
eas of intense flame, which leaves a bright orange
each site to be surveyed with the prism rod.
residue. To confirm that sites were free of contami-
nation, samples of the surface sediment were ana-
A control point located on the platform of an
lyzed using the laboratory method.
observation tower in Area C pond was surveyed in
Conditions at each site, such as water depth,
from "BM Crane," one of the four permanent sur-
vegetation, water conductivity, pH and redox po-
vey benchmarks with known coordinates and ele-
tential, were recorded. Water depth was measured
vations located on high points around the perime-
using a tape measure, vegetation was identified by
ter of ERF. The surveyed-in control point on the
Dr. Charles Racine, and water conductivity, pH
tower platform was then used as a temporary
and redox potential were measured with a YSI
benchmark (TBM). Universal Transverse Mercator
Model 3500 water quality meter.
(UTM) coordinates and the elevation were calcu-
lated for the TBM. This TBM was then used to pro-
vide horizontal and elevation control for the sur-
Measurement of sediment temperature
vey of the transect through Area C.
and moisture
Sediment temperature and moisture were mea-
The electronic total station was set up on the
sured every 10 minutes and averaged hourly from
tower platform, over the control point, and the in-
May 25 to August 26 using sensors interfaced with
strument was back-sighted to a reference azimuth
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