Jump to main content or area navigation.

Contact Us



Natural Resource Damage Assessment

NRD Logo


This information is provided for EPA Regional staff and the general public as a reference tool to facilitate their understanding of the Natural Resource Damage Assessment (NRDA) process. Natural Resource Trustees conduct NRDAs to calculate the monetary cost of restoring injuries to natural resources that result from releases of hazardous substances or discharges of oil. Damages to natural resources are evaluated by identifying the functions or 'services' provided by the resources, determining the baseline level of the services provided by the injured resource(s), and quantifying the reduction in service levels as a result of the contamination. Regulations for assessing NRD have been promulgated under both CERCLA and OPA.

If natural resources are injured by a discharge or release of a mixture of oil and hazardous substances, the DOI regulations are used. The NOAA regulations are applicable only in assessing damages which may result from discharges of oil

DOI Regulations

Section 301(c) of CERCLA requires promulgation of regulations for the assessment of damages for injury to, destruction of, or loss of natural resources resulting from a discharge of oil or release of a hazardous substance. The responsibility for this rulemaking was delegated to the Department of the Interior (DOI) by the President in Executive Order 12580 (January 23, 1987).

DOI's regulations provide a framework and standards for the NRDA process in coastal and marine environments (Type A) and other environments (Type B). The Type A process involves the use of a computer model to assess damages, in a standard and simplified manner, that result from chemical or oil discharges in coastal and marine environments. The Type B process is used in situations that require an individual approach. Both Type A and Type B regulations call for the following four sequential phases in the assessment of damages [43 CFR 11]:

Phase 1: Pre-assessment Screen. A pre-assessment screen is conducted to determine if additional action is warranted. Trustees must determine whether an injury has occurred and a pathway of exposure exists. The pre-assessment screen is a prerequisite to conducting a formal NRDA.

Phase 2: Assessment Plan. Trustees must confirm the exposure of Trust Resources and develop an Assessment Plan to identify how the potential damages will be evaluated. Type A Assessment Plans document that the conditions for use of the Type A procedures are met, provide the site-specific data inputs the Trustee will use to run the computer model, and provide the results of a preliminary application of the model. Type B Assessment Plans to identify the site-specific studies the Trustees will conduct and quality control/assurance procedures. Draft Assessment Plans under both Type A and Type B procedures must be available for public review and comment..

Phase 3: Assessment Implementation. The purpose of the Assessment Implementation phase is to gather the data necessary to quantify the injuries and determine damages. The work consists of three steps: (1) injury determination; (2) quantification; and (3) damage determination. Under Type A, these steps are performed through a computer model. Under Type B, the steps are performed through laboratory and field studies. Trustees quantify injuries by identifying the functions or "services" provided by the resource; determining the baseline level of such services; and quantifying the reduction in service levels that result from the impacts.

Phase 4: Post-Assessment. Trustees prepare a Report of Assessment detailing the results of the Assessment Implementation phase. When Trustees use a Type A procedure, the Report will include the printed output of the final model application. A reasonable number of restoration alternatives including natural attenuation are usually proposed. A preferred alternative is selected based on several factors, including technical feasibility, relationship of costs to benefits, and consistency with response actions.

The regulations also require Trustees to coordinate the assessment efforts, including the pre-assessment screen, with the lead response agency in any situation where response activity is planned or underway at a particular site [40 CFR 11.23(f)]. The Trustee Information and Query Report provides information regarding activities underway at CERCLA sites.

NOAA Regulations

Section 1006(e)(1) of OPA requires that the National Oceanic and Atmospheric Administration (NOAA) develop regulations for the assessment of NRD which may result from a discharge of oil (except for any part of oil defined as a "hazardous substance" by CERCLA).

NOAA's regulations provide a framework for conducting NRDAs that achieve restoration under OPA. NOAA's natural resource damage assessment regulations include the following three phases [15 CFR 990]:

Phase 1: Pre-assessment. Trustees first determine whether they have jurisdiction under OPA. Then Trustees must determine whether to conduct restoration planning. Trustees determine if it is likely that the discharge has caused an injury, if response actions will adequately address the injuries, and if feasible restoration alternatives exist. If so, Trustees are to proceed with the NRDA.

Phase 2: Restoration Planning. This phase has two basic components: (1) injury assessment; and (2) restoration selection. Injury assessment evaluates whether the discharge has resulted in an adverse change in natural resources and/or services. During the restoration selection stage, the Trustee determines the need for, and scale of, restoration actions. For injury assessments, Trustees quantify the degree and the spatial and temporal extent of the injuries in comparison to baseline conditions. Trustees must develop a Draft Restoration Plan that identifies a primary restoration action to return injured resources to baseline conditions and a compensatory restoration action to compensate for the interim loss of services pending return to baseline conditions. This involves evaluating the range of primary and compensatory restoration alternatives, selecting and justifying a preferred alternative, and preparing the plans. The regulation identifies six specific criteria that must be used to evaluate restoration alternatives. The public must be given the opportunity to comment on the Draft Restoration Plan.

Phase 3: Restoration Implementation. The Final Restoration Plan is presented to responsible parties for implementation, or to fund the Trustees' costs for implementation.

Trustees must coordinate their activities with other Trustees, response agencies and responsible parties when operations are conducted concurrently [15 CFR 990.14]. Trustees may develop pre-incident memorandums of understanding to more efficiently coordinate their activities with response agencies [15 CFR 990.14(b)].

Click here to return to the Ecological Risk Assessment and Natural Resources Damage Assessment page.

Solid Waste and Emergency Response Home | Superfund Home | Innovative Technologies Home