C. Procedure for sample collection.

c. Remove the lids from two 1-L amber bottles. Drill four 1/8-in.-diam

holes in each lid. Insert pieces of 1/8-in. stainless steel tubing, equal to

the height of the amber glass bottle (plus about 2 in.), through each hole.

C. Procedure for sample collection.

a. Place a strip of labeling tape on each amber sample collection bottle.

Weigh the bottle and lid, and record this weight on the tape.

b. Label each collection vessel with the sediment identification, column

leach apparatus number, sample number, and parameter code. Suggested

parameter codes are PAH = polycyclic aromatic hydrocarbons, PCB =

polychlorinated biphenyls.

c. Remove the lids from the weighed bottle and replace them with the lids

described above. Place the bottle on the base of the Fraction Collector.

Connect the silicone tubing described above to the stainless steel tubing

on top of the lids.

d. Set the time-based control module on the Fraction Collector to collect a

minimum of 500 mL of leachate sample per collection vessel.

D. Procedure for sample preservation.

a. After collection, place the original lid on each leachate sample, and

reweigh. Determine the weight of sample collected, by difference, and

record this weight.

b. Immediately after collection, store samples at 4 EC.

E. Data presentation.

The data for contaminant of concern should be presented in tables that

include contaminant concentrations and concentrations of other relevant

chemical species such as chloride ion, total organic carbon, pH, and electrical

conductivity as a function of pore volumes eluted (T).

F. Data analysis.

Column leach tests are laboratory-based physical models of contaminant

leaching in a CDF, designed to show leachate concentration (C) as a function of

pore volumes eluted (T). Unlike freshwater sediment leaching, where maximum

leachate contaminant concentrations occur at the beginning of leaching,

estuarine sediment leaching yields maximum leachate contaminant

concentrations after a number of pore volumes have been leached. This

phenomenon is the result of the release of colloids as ionic strength decreases.

Examples of elution curves can be found in Myers, Brannon, and Tardy (1996)

http://www.wes.army.mil/el/ dots/pdfs/trd961.pdf.

D20

Appendix D Leachate Testing Procedures