The Building Authority (BA) has just revised Practice Note for Authorized Persons and Registered Structural Engineers 252 on Management Framework for Disposal of Dredged/Excavated Sediment.
http://www.bd.gov.hk/english/documents/pnap/Pnap252.pdf is the direct link to the document in the website of the Buildings Department (BD).

Please also take note that PNAP 155 on Marine Disposal of Dredged Mud is hereby withdrawn.

Frequent visits to the BD's homepage at http://www.bd.gov.hk will keep you abreast of the BA's latest announcements.