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SOP1 – Ballast Operations
8
Again, make sure you have an IMAC ‘event’ in progress prior to transitioning to UPTAKE and
sampling.
Note that vendor equipment (treatment system) may affect pump-discharge pressure for pump-2;
therefore, monitor the situation closely during transition of flow to a vendor. Note also that tanks
filling will create an approximately 5 psi increase in pump discharge pressure as head builds
from empty to full. Adjust backpressure accordingly if deemed necessary or advisable.
Injection of challenge condition enhancements (slurry/mud and/or added biota) will (as dictated
by test-plan) be started during or just prior to the transition from sea-to-sea to uptake. Injection
occurs at the upstream side of the sea-strainer before the split to pumps one and two. Preparation
and injection of challenge condition enhancement is detailed in SOP 3.
2.4. Uptake Operations (UT) – filling both tanks simultaneously
With
both
top and bottom tank hatches opened, confirm that inlet grates inside the tanks are
firmly set/wedged over fill/drain opening. Use hands to check wedges are snug. Reseat (tap with
hammer) if loose.
Timing transition of flow to treatment system and tanks from sea-to-sea is to be discussed in the
operations meeting before start-up. Prototype treatments or R&D jobs require especially close
coordination between MERC and vendors. Treatment systems not adding active substances may
be linked in on sea-to-sea mode and then transition to uptake when ready. Note that substances,
such as chlorine, will not routinely be added while in sea-to-sea mode because of EPA discharge
laws. To open flow to the vendor open the two valves sending water to/from vendor and only
then close the two valves of the vendor bypass and open 1.5”drain on the bottom of the bypass to
ensure no untreated water enters tank-2.
To switch from sea-to-sea to uptake (with or without vendor online) open primary and secondary
tank isolation valves, shut fill/drain lower trunk (under tanks) drains located starboard near
gangway as well drains on forward end of the lower fill/drain trunks to fill tanks fully. Close
1.5” bottom drain of double-block on path to tank. Leave double-block valve nearest pinch-valve
closed for now as new ‘block’ valve for transition of flow from sea-to-sea to sea-to-tank.
Either pump/tank may be transitioned first; however, transitioning the control system (#1 aft)
first is preferred as that side of the system is not complicated by treatment and the control pump
may be slowed towards the end for a simultaneous finish without affecting conditions of flow
and pressure provided to vendor. Alert vendors, sampling team and any other concerned
personnel that uptake will commence and pressures may vary (drop) momentarily until
readjusted for the new line-up. Open new ‘block’ valve ahead of closing old ‘sea-to-sea’ ‘block’
valve. It is important to remember not to shut sea-to-sea first. If necessary retune pressure to
target with technique described above for sea-to-sea.
Repeat for treated pump/tank system (#2 forward). Keep extra close watch on pressure. When a
tank starts to fill, sampling immediately begins as defined in SOP 4. If not done already, close,
dog down and lock the lower tank hatches or water will overflow lower edge of hatch within just
a few minutes. Note – as filling proceeds, check lower hatches for leakage. Adjust hatch-dogs as