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MERC STDN Test Plan
4
initial filling of control and test tanks to increase TSS, POC and DOC levels. Details on these
processes are available upon request and will be provided in the final report.
Summary of MERC Land-Based Facility and Sampling Design:
MERC will evaluate the biological
efficacy of the BalPure ballast water
management system onboard the MARAD
vessel M/V
Cape Washington
while docked in
Baltimore Harbor, Maryland (right). The ballast
system of the
Cape Washington
has been
modified to allow for water at a flow rate of
400m
3
/hr to be split equally, and delivered
simultaneously, to a “control” (untreated) ballast
tank and a “test” (passing first through the
BalPure system) ballast tank, each at 200m
3
/hr.
The ship’s ballast tanks to be used for the
required holding time of five days are
essentially identical in size (~ 650 m
3
) and structure. Each tank will be filled to approximately
250 m
3
for test trials. A detailed drawing of the modified ship ballast system can be found on
page 17.
Care was taken in the design of the MERC
Cape Washington
test systems so that water
entering the control and test tanks is handled (e.g., passing through same pump and similar
piping) as close to identical as possible, aside from passing through the BalPure system for
treatment. Three test system performance runs have been conducted to assure that water in both
control and test tanks have near identical physical and biological conditions. While initial
physical and biological conditions are subject to natural variability, the MERC test system itself
is not a source of mortality (data available upon request). The test ballast tank will also drained
and manually rinsed/cleaned prior to conducting the first evaluation trial, and rinsed/flushed with
20 – 30 m
3
of potable water and drained completely between trials, to avoid the possibility of
residual live organisms in the bottom of the empty test tank influencing results.
Five sequential samples will be taken for each of the following: (A) initial/intake
conditions, just prior to the split of control and treated water, (B) initial conditions just
downstream of the BalPure system during filling of test tank, (C) control water upon discharge
after a five-day holding time, and (D) treated water upon discharge after a five-day holing time.
Sample volumes and details of the physical, chemical, and biological analyses for each sample
are described below.
A detailed drawing of the MERC
Cape Washington
test setup and
sampling design is available on page 18.
All samples collected to quantify live organisms or water quality will be taken by inline
sampling of ballast water during the initial filling or during discharge of water from the ship’s
tanks by sample ports place in appropriate filling or discharge pipes. All sample ports include a
valve and sample tube with a 90
o
bend towards the direction of flow, placed in the center of the
piping system (based on the design developed and validated by the US Naval Research
Laboratory, Key West Florida).
A total of 10 identical conical bottom mesocosms (shown below) have been installed on
the
Cape Washington
to allow for precise and controlled sampling during each test trial. Five
replicate mesocosms are used to sample initial, challenge conditions at the start of each trial,