The purpose of this handbook is to provide state-of-the-art guidance on the subjects of sampling, preservation, and analysis of dredged and fill material. This need developed as a result of the promulgation and implementation of Section 404(b) of Public Law (PL) 92-500 (Federal Water Pollution Control Act Amendments of 1972) which required the ecological evaluation of proposed dredging and filling operations as they may impact navigable waters of the United States. It is expected, therefore, that this manual will receive wider usage as an aid in the regulatory process rather than a research tool. The initial guidance for implementing Section 404(b) was released in 1976. The guidance presented in this handbook should be viewed as second-generation Interim Guidance in the continuing process of procedure development, refinement, and evaluation. Thus, it will be intermediate between the initial Interim Guidance and analytical compediums such as Standard Methods. American Society of Testing and Materials (ASTM) manuals, or Environmental Protection Agency (EPA) manuals. The major emphasis of this effort has been to provide guidance on the subjects of sampling, sample handling, and sample pretreatment.