D.4.1 Column materials and apparatus

versus the sediment concentration, q, (y axis) for each leach cycle. Units

for q are mg/Kg and units for C are mg/L. Units for Kd are L/kg.

D.4 Pancake Column Leach Test for Estuarine

Sediments

The Pancake Column Leach Test (PCLT), used to evaluate potential leachate

quality in estuarine dredged material, serves as a laboratory-scale physical model

of contaminant elution from dredged material that includes advection-dispersion,

colloid, release, and other mass transfer effects. Contaminated sediment is

mixed, weighed, and loaded into the column leach apparatus. DDI1 water is

introduced into the loaded column over an extended time interval. Water flow is

controlled by a constant-volume pump. Leachate samples are collected at

specified time intervals and are analyzed for COC.

D.4.1 Column materials and apparatus

Column Leach Apparatus (Figure D-6)

Kg weighing scale

Two 9/16-in. open-ended wrenches

One 10-in. crescent wrench

Mechanical mixer

Polyethylene beaker (5,000 mL)

Stainless steel spatula, 12 in.

Stainless steel spatula, 6 in.

Polyethylene scoop

Paper towels

Glass fiber filter, 1 micron, 257-mm diam, binder free, (Gelman Type

A/E or equivalent)

Polyethylene gloves

DDI water is the appropriate challenge water when the sediments will be exposed to

freshwater infiltration in the CDF. In some cases, dredging site water may be a more

appropriate challenge water (see Section D.2.5).

D13

Appendix D Leachate Testing Procedures