Silt Posted on 21st December 20157th May 2021 by ThePD (The Project Definition) Silt is the fine particles of sand and rock that is found as the deposit of sediment at the mouth of a river. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Substance and tagged solid. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.