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SOP1 – Ballast Operations
5
filled with water that has been treated. Both ballast system design and operations protocols were
developed to eliminate any chance of the treatment being contaminated by the control. All efforts
are made to avoid contamination, particularly given zooplankton concentrations in the control
water are typically above 100,000/m
-3
and treatment water is targeting less than 10 live
organisms
>50-µm in size
per m
-3
on discharge. A typical test-cycle begins with pumping water
‘sea-to-sea’, then proceeds to ‘uptake’ or simultaneously fill both tanks while potentially adding
challenge-condition enhancements to the water as required (see SOP3) before passing it through
treatment on the way to the tank. Depending upon the test plan, a hold-time of 24h, 2d , 3d, or 5d
follows. The test-cycle finishes with consecutive discharge and sampling of water that was held
in both the treated and control tanks. The pipe and valve system also allows for other procedures
including water movement between tanks and water movement sea-to-sea using one pump at a
time. As specified by ETV, sampling occurs at fixed rates during the whole time any tank is
either filled or emptied (SOP 4).
The pumps can generate pressures in excess of 50 psi; however, operations at 30 psi are more
typical. Pump controls incorporate protective automatic shutdown features preventing damage in
case of dry-run, dead-head or other potentially damaging situation. The pumps are not self-
priming, pipes leading to and from the pumps must be fully primed with water before pumps are
energized. During normal operations the pumps are controlled via the IMAC screen.
2.2. Precautions and Safety
Setting up the valves and priming the pumps for a test requires climbing up on the pump and
pipes assembly, which will often be wet and slick. Therefore,
cautious and deliberate
movements are required
both for personal safety and to prevent damage to valve handles, meters
and sensors. Appropriate close-toe footwear is a must. In addition before entering a tank to
check off QA/QC items such as cleaning or grate security ensure all safety measures are taken
(as listed in the barge safety manual) including ensuring that both top and bottom tank hatches
are open as well as communicating your intentions to at least one other person who will monitor
your movements while you are within.
Operating the pumps require an
open flow path.
Therefore,
always open one path before closing
another.
If a pump is turned on but a flow-path is unavailable then the pump will try to start but
should shut itself off within seconds without damage. This is called ‘dead-heading’ the pump and
the pump controls protect against it. Another bad situation the pump controls guard against is
called ‘dry-run’. Dry run occurs if an operator attempts to start a pump that is not primed, or has
entrained too much air during a run. Failure of pump seals will result from extended dry run.
Despite these protections it is preferred that dead-heading and dry-running be avoided. Also,
when water is in motion and the path is to change,
valves must be moved slowly
, especially
closing the last 20 degrees or issues such as water-hammer or pump stoppage may arise.
Automatic pump stoppages create a fault warning which must be cleared off the IMAC screen by
pushing the appropriate ‘clear’ button prior to restarting the pump. It is worth repeating that
ballast pumps will not be run until the pump and pipes configuration (the water flow-path) is
systematically double-checked.