Data Collection Requirements of Risk Assessment

The identification of COCs during Tier I depends in part on the toxicological

importance of each contaminant. This Tier I task therefore provides a start on the

risk assessment's Toxicity or Effects Assessment which answers the question, "Is

there a known quantity of the chemical or physical hazard which results in an

adverse effect to the likely receptors?" The risk assessment may require that this

information be reformulated to conform to the parameters used in human health or

ecological exposure models. This is generally accomplished by reference to

on-line USEPA and USACE databases or an expanded literature review.

The exposure assessment addresses the question, "Are there any conservative

but realistic, activities or physical and biological pathways by which the receptors

may encounter the chemical or physical hazards?" This is a considerable expansion

of Tier I sediment characterizations or Tier II modeling activities and also

incorporates the bioaccumulation testing conducted in Tier III. This is the risk

assessment component which will require the most expansion upon prior data

gathering activities because this is the point which integrates the site selection

information with the dredged material evaluation. Although it generally will not

require new data collection, it will require a reformulation of the information into a

site-specific conceptual model.

In summary, the activities of site selection and dredged material evaluation

provide most of the information needed to conduct a risk assessment. There will be

some necessary renewed literature reviews and a reformulation of the data, but

expensive, time-consuming field data collections are unlikely.

Chapter 1 Overview of Ecological and Human Health Risk