National Resource Damage Assessments (NRDA)
The Water Column Exposure Modeling Toolbox (WCEMT) is a set of modeling tools developed to meet the needs of Natural Resource Damage Assessments (NRDA) for viable methods to assess ecological impacts of significant marine oil spills based on limited empirically obtained petroleum chemistry data. The developed modeling tools estimate water column exposures of Total Petroleum Hydrocarbon (TPH) and 50 Polycyclic Aromatic Hydrocarbon compounds (PAH50) resulting from the entrainment and dissolution of surface oil into the upper water column and subsequent transport/and or ultimate fate of the relevant oil fractions. These tools can be used together to determine petroleum hydrocarbon exposure of fish eggs in the water column. The vertical transport models for crude oil and/or fish eggs are based on the fundamental advection diffusion equation. WCEMT has been applied to a chronic oil spill in the Gulf of Mexico at Mississippi Canyon lease block #20 to assess damages and identify observational data needs for future spill assessments.