Hi,
I'm working on tankers transporting A1 around. A1 has one of the highest specs and can be a total nightmare when the ship has previously transported another clean product around due to the level of cleaning required in the ships tanks to make sure it is not contaminated.
But it has to be remembered where this is being used and the importance to delivering on spec cargo to terminals.
First of all, you've noticed you have contaminated cargo so you have a contaminated tank. if you decided to jettison everything in that tank you're going to have to go tank diving to verify it's clean before you put anything else in there.
You can't rely on strainers to do the job because they'll either become blocked when you reach the bottom of the tank or if these particles are suspended when pumping at high rates you'll have a good chance you'll just break through the strainer if these particles are large.
Strainers are rated for the pump suitable for that tank and these will vastly be different to a fuel filter on an aircraft if it manages to pass through your filters.
You've got off spec fuel now, all you can do as a responsible ship operator is get rid of it ashore. Clean the tanks thoroughly and replace the filters on your pumps.
Expensive problem caused by a more common problem than you would imagine in the shipping world. Save your reputation for a few thousand dollars rather than your owners chopper ditching because of the mistake.