The purpose of this handbook is to assist environmental restoration (ER) projects in the preparation of a data management implementation plan (DMIP). The DMIP identifies and documents an ER project's requirements and responsibilities for the management, quality assurance, use, and archival of its environmental data. It is important that a project complete its DMIP in the early planning phase to ensure that the necessary and appropriate data management systems and personnel are in place before the project begins acquiring data. All ER projects that collect or use environmental data at the Oak Ridge National Laboratory, the Oak Ridge Y-12 Plant, the Oak Ridge K-25 Site, the Paducah Gaseous Diffusion Plant, the Portsmouth Gaseous Diffusion Plant, and surrounding onsite and offsite areas must prepare a DMIP. Project types that often collect environmental data include surveillance and maintenance, decontamination and decommissioning, remedial design/remedial action, and remedial investigation/feasibility studies. Even if a project does little environmental data management, a DMIP is required to document this fact.