Describes methods recommended for the selection of sampling stations within an environmental study site, and the collection, handling, storage, transportation, and manipulation of samples of whole sediments from marine, estuarine, and freshwater environments. Outlines general methods and procedures for two types of undertakings: monitoring and assessment studies, and studies specified in permit requirements for open-water disposal of dredged materials. Included in the general procedures are recommended methods of collection for test, control, and reference sediment, in-situ collection of pore water, sample handling, transportation, storage methods or conditions, and whole-sediment sample preparation for bioaccumulation tests, physicochemical characterisation, and/or toxicity testing. Methods are also recommended for the laboratory collection of pore water and elutriate from field-collected whole-sediment samples. Additional procedures or conditions specific to the various aquatic environments are also addressed.