Environmental restoration activities are currently under way at several sites owned by the US Department of Energy (DOE) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. DOE is the CERCLA lead response agency for these activities. Section 120(a) of the Superfund Amendments and Reauthorization Act also subjects DOE to liability under Section 107 of CERCLA for natural resource damages resulting from hazardous substance releases at its sites. The Natural Resource Damage Assessment (NRDA) process, by which natural resource injuries are determined and compensatory monetary damages are calculated, is not well known or understood by DOE staff and contractors involved in environmental restoration activities. Nevertheless, natural resource liabilities are potentially a significant source of additional monetary claims for CERCLA hazardous substance releases. This paper describes the requirements of NRDA and explains how to integrate the NRDA and CERCLA Remedial Investigation/Feasibility Study processes, in order to more quickly restore environmental services at the lowest total cost to the public. The first section of the paper explains the statutory and regulatory mandates for the NRDA process. The second section briefly describes the four phases of the NRDA process, while the third section examines the three steps in the assessment phase in considerable detail. Finally, the last section focuses on the integration of the CERCLA and NRDA processes.