Sediment contamination is a widespread environmental problem that can potentially pose a threat to a variety of aquatic ecosystems. The sediment test methods in this manual will be used by The United States Environmental Protection Agency (USEPA) to make decisions under a range of statutory authorities concerning such issues as: dredged material disposal, registration of pesticides and toxic substances, superfound site assessment, and assessment and cleanup of hazardous waste treatment, storage, and disposal facilities. The use of uniform sediment testing procedures by USEPA programs is expected to increase data accuracy and precision, facilitate test replication, increase the comparative value of test results, and ultimately, increase the efficiency of regulatory processes requiring sediment tests.