Environmental damage caused by oil or hazardous material spills can devastate an area. After an oil spill or hazardous substance release, response agencies clean up the substance and work to reduce or eliminate the damage to human health and the environment. Sometimes these efforts do not fully restore injured natural resources or address their lost uses by the public.

The Natural Resource Damage Assessment (NRDA) Program is the legal and technical process designed to restore the damaged area and ensure that those responsible—and not taxpayers—pay for restoring the affected area and that the public is made whole.

The Texas General Land Office NRDA Trustees act on behalf of the public to identify the injured natural resources and determine the extent of the impact. They also recover damages from responsible parties to plan and carry out restoration activities. In Texas, three state agencies are designated by the Governor as NRDA trustees:  the Texas General Land Office (GLO), the Texas Parks and Wildlife Department (TPWD) and the Texas Commission on Environmental Quality (TCEQ). 

On the federal level in Texas, the NRDA trustees are most often the National Oceanic and Atmospheric Administration (NOAA), the Department of the Interior (DOI) with authority delegated to the U.S. Fish and Wildlife Service (USFWS), The United States Environmental Protection Agency, and the United States Department of Agriculture are Federal Trustees in the Deepwater Horizon Oil Spill case.