Annual Sludge quantity estimation in a Port

Hi everyone,
I am a student in environmental sciences in Benin and for bachelor thesis, i’m working on the setting of a sludge oil management plan for Cotonou Port in Benin.
To do so, i will need inter alia to estimate the quantity of sludge oil which could be disharge by vessel at the Port.
Then my concern is about the method to use to do such a thing. So in the expectation to have some answer, have my best regards
(I expect that I have posted my thread at the good place. Beside that i am a francophone and my english level is a little weak : i expect also that you understood me)