H.2.6 Comparison of DTPA results to reference

described in (http://www.wes.army.mil/el/elmodels/pdf/ee-04-12.pdf). The

program can be downloaded from (http://www.wes.army.mil/el/elmodels/index.

html). Plant contaminant concentrations from several years of plant

bioaccumulation results are contained in the PUP database and are separated by

sediment redox status, pH and organic matter. Data separation improves the

prediction capability when the data collected from the above procedures are

entered into the PUP model and model results are generated.

H.2.6 Comparison of DTPA results to reference

The mean DTPA and total sediment metal concentrations are entered along

with pH and organic matter content into the PUP as described in Folsom and

Houck (1990). Results are presented as plant metals concentration in ug g-1 and

as total plant bioaccumulation in ug on an ODW basis. In addition, test results

from the reference sediment are included for comparison.

An example DTPA evaluation using PUP as described above is shown in

Table H.1. The DTPA results are noted as exceeded (EXCD) the comparison or

did not exceed (DNEX) the comparison. As shown in this example, As, Cd, Cr,

Cu, Pb, Hg, and Zn exceed all cases comparing plant bioaccumulation from the

dried dredged material to bioaccumulation from the reference material.

Table H.1

Summary Of DTPA-Predicted Plant Bioaccumulation from Dredged

Material Compared to Reference Material

No.

Case

Exceeded

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

DNEX

EXCD

The results of the comparisons show that dredged material DTPA Cd, Cu,

Cr, Pb, Hg, and Zn will exceed the reference all cases described above. This

information is evaluated according to the Tier II guidance in Chapter 9.

The plant metals concentrations and total plant bioaccumulation predicted by

the PUP program for the example summarized above are presented in Table H.2.

This information may provide perspective useful in the Tier II evaluation of

plant bioaccumulation.

Appendix H Plant Bioaccumulation Procedures