Initial Estimate of Exposure Point Concentration for Total PCBs

Attribute

Flounder Body Burdens of PCBs

Closeness of correspondence to the assessment end point

Moderate - the measurement of body burdens is not a direct

measure of fish health or reproductive capacity

Site specificity

Strong - the fish probably acquire body burdens due to

exposure to site-related contaminants

Correlation of stressor to response

Moderate - there is evidence in the literature indicating

relationships between body burdens of COCs and changes in

fish physiology, reproduction, and growth

Availability of an objective measure for judging environmental

Moderate - there are no promulgated standards for protection

harm

of ecological receptors based on body burdens. However,

the USACE assembled a "residue effects" database for

Sensitivity of the measurement end point for detecting changes

Moderate - the literature indicates a wide range in tolerance

among fish species for body burdens of various COCs

Quantitative

Strong - the measurement is quantitative

Use of a standard method

Strong - there are accepted methods for analysis of COCs in

tissue

Initial Estimate of Exposure Point Concentration for

Total PCBs

The risk assessor has calculated the upper 95th-percent confidence limit on the

arithmetic mean concentration of total PCBs based on Tier I measurements. This

value is 1 ug total PCB/g sediment. The risk assessor has decided that the area of

influence is equal to about one tidal excursion based on the description of the

local environment as moderately energetic. The State Department of Marine

Fisheries provided local oceanographic information to calculate the tidal

excursion lengths. The management area and its area of influence are collectively

referred to as the disposal site area.

Estimating a Body Burden in Winter Flounder

The dredged material management area and its area of influence (defined

previously as the area within one tidal excursion of the site) is approximately

equal to one-half the summer foraging area of the winter flounder, based on

observations made by the state's Department of Marine Resources. This species

is a selected receptor, based on its commercial importance.

The proposed site is within the State Statistical Fishery Area 4 and is 2

percent of that area.

Appendix F Hypothetical Example