profiles of the water column were made and
allowed automatic control of the generator and
water quality samples taken. The measurements
automatic startup and stopping of the pump sys-
showed that a prism of fresh water discharged
tem, controlled by float switches that would cycle
from a series of small springs and seeps along the
the pump as the pond emptied or started to refill.
upland border slowly displaced the brackish
Once funds became available, the requisition pro-
cess was initiated in March 1995. Procurement
water that filled the ponds in this area after a
problems delayed the award of the sole-source
flooding high tide. The formation and extension
contract for the purchase of the system until July.
of the prism of fresh water as it rides over and
During the first week of September the contractor
displaces the brackish water could be seen in the
completed the pump system and conducted a
weekly measurements of the water temperature
performance test at the contractor's facility in
and salinity of the water column at seven meas-
Montana. After the final tests, the pump system
urement sites. From the measurements, rates of
was shipped by truck to Anchorage, arriving on
inflow of fresh water were estimated. A model of
12 September. Because the pump system was de-
freshwater flow was used to estimate a maximum
livered so late in the season, it was not deployed
volume of the freshwater inflow in the two con-
to the Bread Truck Pond. Instead, we deployed
nected ponds after 20 days of approximately
10,615 m3. This equates to 530 m3/day of fresh
the system in Clunie Inlet to completely test the
system and to run the generator for the initial 40-
water produced by runoff, seeps, and springs
hour break-in period. This allowed us to check
along the 445-m total length of upland boundary
fuel procedures and fuel consumption rates and
bordering the pond system. This is equivalent to
0.0061 m3/s, or only about 1/20 the pumping
to ensure that all sensors and controls were oper-
ational. Initially, we had some problems getting
capacity of the pumping system to be installed in
the controls to start the pump. It turned out that a
the BT Pond, indicating the system would be
control wire connection had come loose during
more than capable of keeping up with freshwater
transport and a fuse in the control panel blew
inflow from the C/D Area. Because of the unusu-
after the loose wire shorted out. After we repaired
ally wet summer this year, with above-average
the wire and replaced the fuse, the system was
rain from July through September, this discharge
started normally. Water was pumped for approxi-
rate is probably higher than during an average
mately 7 hours a day for 5 days until the genera-
summer.
tor had the required 40 hours of running time on
it. Following the completion of the test, the sys-
Collins, C.M., M.T. Meeks, and M.E. Walsh
(1998) Draining of Racine Island Pond by explo-
tem was pulled out, the discharge line disassem-
sive demolition of a drainage ditch. In Interagency
bled and the components shipped back to Ft.
expanded site investigation: Evaluation of white phos-
Richardson DPW for winter storage.
phorus contamination and potential treatability at
Task 3 was to determine the rate of surface
Eagle River Flats, Alaska (C.M. Collins and D. Cate,
water inflow into the C/D Area from the adjacent
Ed.). CRREL Contract Report to U.S. Army, Alaska,
uplands and how that rate of inflow might influ-
ence the BT Pond. Two instrumented sites were
Directorate of Public Works, FY97 Final Report, p.
installed in the C/D Area in early June to monitor
6380.
water conditions. One site was located at the east-
In April 1997 we successfully conducted an
ern edge of the C/D Area next to the upland bor-
operation to permanently drain a pond in Eagle
der along the shore of a deep, narrow pond run-
River Flats contaminated with white phosphorus.
ning parallel to the upland border. The second
This pond, located in the center of Racine Island,
site was located at the far western end of the pond
was one the most highly contaminated in Eagle
system that extends through the C/D Area
River Flats, with measured concentrations of
toward the BT Pond, perpendicular to the first
white phosphorus of up to 3071 mg/g. We
pond and the upland border. These two sites were
drained the pond by using explosives to excavate
instrumented to monitor pond water levels as
a drainage ditch connecting the pond with a near-
well as water temperature, salinity, and specific
by tidal drainage gully leading to Eagle River.
conductance. Seven additional sampling sites
This year's operation built on the success of a
were located along two transects, one parallel to
similar operation last year to drain Bread Truck
the upland boundary and one perpendicular to
Pond. Using explosives to excavate drainage
the boundary. At these sampling sites, periodic
ditches is an efficient and cost-effective method of
water salinity and temperature measurement
permanently draining a pond where the potential
39
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