B.2.1 Apparatus

(SS) under quiescent settling conditions. The test consists of mixing a sediment

sample with dredging site water to form a slurry, allowing the slurry to settle under

conditions equivalent to those in a CDF, then extracting an effluent elutriate

sample for chemical analysis. Field verification studies have shown that the

effluent elutriate test is a conservative predictor of CDF effluent quality (Palermo

1985a-d; Palermo and Thackston 1988a and b).

The effluent elutriate tests should be conducted, and appropriate chemical

analyses should be performed as soon as possible after sample collection. If

effluent elutriate tests for both water quality and toxicity evaluations are to be

conducted, sufficient effluent elutriate should be prepared for both purposes. The

volume of effluent elutriate needed for water quality evaluations will vary depend-

ing upon the number and types of chemical analyses to be conducted. Both

dissolved and total concentrations of contaminants may be determined. The

volume required for each analysis, the number of variables measured, and the

desired analytical replication will influence the total elutriate sample volume

required. A 4-L cylinder is normally used to prepare the elutriate, and the super-

natant volume available for sample extraction will vary from approximately 500 to

1,000 mL, depending on the sediment properties, settling times, and initial

concentration of the slurry. It may be necessary to composite several extracted

sample volumes or to use large diameter cylinders to obtain the total required

volume.

B.2.1 Apparatus

The following items are required:

a. Laboratory mixer, preferably with Teflon shaft and blades.

b. Several 4-L graduated cylinders. Larger cylinders may be used if large

sample volumes are required for analytical purposes. Nalgene cylinders

are acceptable for testing involving analysis of inorganic compounds such

as metals and nutrients. Glass cylinders are required for testing involving

analysis of organic compounds.

c. Assorted glassware for sample extraction and handling.

d. Compressed air source with deionized water trap and tubing for bubble

aeration of slurry.

e. Vacuum or pressure filtration equipment, including vacuum pump or

compressed air source and an appropriate filter holder capable of

accommodating 47-, 105-, or 155-mm-diam filters.

f. Presoaked filters with a 0.45-um pore-size diameter.

g. Plastic sample bottles, 500-mL capacity for storage of water and liquid

phase samples for metal and nutrient analyses.

Appendix B Column Settling Test and Effluent Elutriate Procedures