Natural Resource Damage Assessment (NRDA)
How Natural Resource Damage Assessment Works
After an oil spill or hazardous substance release, response agencies like the
U.S. Environmental Protection Agency or the U.S. Coast Guard clean up the
substance and eliminate or reduce risks to human health and the environment.
But these efforts may not fully restore injured natural resources or address
their lost uses by the public. Through the NRDA process, DARRP and co-trustees
conduct studies to identify the extent of resource injuries, the best methods
for restoring those resources, and the type and amount of restoration required.
NOAA conducts the following three steps in an NRDA:
1. Preliminary Assessment
Natural resource trustees determine whether injury to public trust resources has
occurred. Their work includes collecting time-sensitive data and reviewing
scientific literature about the released substance and its impact on trust
resources to determine the extent and severity of injury. If resources are
injured, trustees proceed to the next step.
2. Injury Assessment/Restoration Planning
Trustees quantify injuries and identify possible restoration projects. Economic
and scientific studies assess the injuries to natural resources and the loss of
services. These studies are also used to develop a restoration plan that
outlines alternative approaches to speed the recovery of injured resources and
compensate for their loss or impairment from the time of injury to recover.
3. Restoration Implementation
The final step is to implement restoration and monitor its effectiveness.
Trustees work with the public to select and implement restoration projects.
Examples of restoration include replanting wetlands, improving fishing access
sites, and restoring salmon streams. The responsible party pays the costs of
assessment and restoration and is often a key participant in implementing the
Although the concept of assessing injuries may sound simple, understanding
complex ecosystems, the services these ecosystems provide, and the injuries
caused by oil and hazardous substances takes time—often years. The season the
resource was injured, the type of oil or hazardous substance, and the amount
and duration of the release are among the factors that affect how quickly
resources are assessed and restoration and recovery occurs. The rigorous
scientific studies that are necessary to prove injury to resources and
services—and withstand scrutiny in a court of law—may also take years to
implement and complete. But the NRDA process described above ensures an
objective and cost-effective assessment of injuries—and that the public's
resources are fully addressed.