NRDA Trustees must be notified if more than 500 gallons (12 bbls) of oil are discharged or if discharges of lesser volumes of oil result in potential impacts to natural resources, including oiling of habitats, or occur in sensitive environments such as wetlands.
They must also be notified about all releases of hazardous substances that have the potential to result in damage to natural resources. Even relatively small volumes of hazardous substances can have extremely toxic effects in the environment.
There are federal and state rules that outline the organizational structure and the process for responding to an oil spill or the release of hazardous substances. The National Contingency Plan (NCP) directs On-Scene Coordinators (OSC) to work with all Natural Resource Trustees during specific response activities.
Trustees identify and prioritize natural resources at risk to help ensure that they are protected. During an emergency response, Trustees provide technical assistance to the OSC including response techniques within environmentally sensitive areas and wildlife recovery and rehabilitation. They also provide information on threatened or endangered species and their habitat, archaeological, cultural and historic sites, and other natural resources and land areas under their jurisdiction. Trustees advise the OSC on cleanup strategies and help provide cleanup assessments.
Trustees encourage the Responsible Party (RP) to work cooperatively and jointly with them throughout the pre-assessment, assessment, and restoration phases of the NRDA process. This reduces assessment costs and maximizes “restoration acres-on-the-ground.” Settlement Agreements or Consent Decrees formalize the RP's commitment to work with, implement, or fund restoration projects sufficient to compensate for lost natural resource services.
Restoration projects are preferred as compensation, as they most directly replace the services lost. Projects are selected as near to the impact site as possible and as close in habitat character as practicable. The Trustees may also settle for compensatory funds of sufficient value to ensure that projects of sufficient size and longevity can be constructed to offset the resource services lost.