Select and characterize human receptors

material management site. Using a representative species approach is a commonly

accepted technique in regulatory practice. For example, this approach has

historically been used in other Clean Water Act regulatory activities such as 301h

and 301b demonstrations.

Select and characterize human receptors

The assessment should specify the human receptors who may use the

management site, local residents living or working near the site, and workers who

may contact sediments during dredging, transport, or management of the materials.

Obviously, the types of human receptors will vary with the technology employed in

the dredged material management activity and the location of the activity. The likely

list of potential human receptors include:

a. Potential recreational users of the site (swimmers, boaters, fishermen,

naturalists, waders).

b. Local residents (off-site resident, trespasser - depends on proximity of

management site to shore).

c. Workers (barge operators, onsite workers, facility workers, pretreatment

workers - depends on the technology used).

Select ecological receptors

This step identifies the receptor species and provides the rationale for their

selection as representative receptors from among the species likely to occur in the

disposal site area.

The actual receptors chosen will vary among disposal sites. However, general

guidance for receptor selection is to select those species which:

a. Are likely to occur at the site.

b. Represent a reasonable (although not comprehensive) cross section of the

major functional and structural components of the ecosystem under study.

c. Represent various trophic levels (e.g. saprophytes, herbivores, primary and

secondary carnivores), feeding types (detritivores, scavengers, filter feeders,

active predators, forage fish, piscivorous birds), and habitats (benthic,

demersal, pelagic) so that exposure pathways can be evaluated.

d. Represent those types of organisms most likely to encounter the

e. Are relatively abundant and ecologically important within the selected

habitats.

f. Have available applicable toxicological literature.

Chapter 2 Problem Formulation