Services

Natural Resource Damage Assessment (NRDA)

ASA develops computer models for U.S. government regulations that evaluate the physical fates, biological effects, and economic damages of oil and chemicals in marine and fresh water environments. There are existing models with required data included, applicable to small spills in U.S. coastal and marine environments and the Great Lakes, which are incorporated or referred to in CERCLA and OPA Natural Resource Damage Assessment (NRDA) regulations. ASA also provides NRDA services using modifications of these models to incorporate siteand event-specific data for injury quantification, and to evaluate the damages as restoration costs.

Background

ASA developed “Type A” computer models for the U.S. government, which are incorporated in CERCLA and NRDA regulations published in 1996 by U.S. DOI. These models are used in simplifi ed and more detailed damage assessments for chemical spills under CERCLA, and for injury quantifi cation and restoration planning for oil spills under OPA. After the regulatory models were completed, ASA model development continued as SIMAP for oil spills and CHEMMAP for chemical spills. In the Type A models, the injury to natural resources is quantified with and without restoration and replacement actions. The economic valuations in Type A models are based on in-situ use values for calculating compensable values (damages due to injuries). For SIMAP and CHEMMAP, a separate habitat restoration model is used.

Habitat Restoration Model

Increasingly, damage assessments have focused on costs of restoration. ASA has developed a habitat restoration model, to be used in conjunction with SIMAP and CHEMMAP, that calculates the amount of restoration needed to compensate for injuries to fish, invertebrates, aquatic birds, and other wildlife and habitats, using production as a metric to balance restoration gains against losses due to the spill. Population modeling is used for scaling of species-specific restoration projects.

ASA provides site- and event-specific modeling assessments to NOAA and other clients, usually involving injury quantification and restoration scaling (rather than economic valuation, in keeping with the OPA NRDA rule, which emphasizes this approach). ASA has performed these services for numerous spills, assisting government trustees in claims against responsible parties. ASA has also performed cost-benefit analyses and NRD risk assessments using probabilistic (Monte Carlo) approaches to determine the range of potential injuries and damages that might result from spills.

ASA has been contracted since 1991 to the NOAA Damage Assessment Center to provide support services in NRDA activities. Tasks under the contract have include:

• Training and preparation activities
• Preparation and review of reports
• Consulting activities
• On-site NRDA activities for particular discharges
• Injury quantification studies
• Restoration scaling
• Litigation support

Natural Resource Damages

Damages include losses to commercial and recreational fishing, hunting of waterfowl, viewing of birds and mammals, and beach use. Total damages include lost use values associated with injuries pending recovery plus the costs of restoration. In addition, damages based on restoration costs are calculated for lost assimilative capacity of the water and sediments while spilled contaminant is present.