7.4 Tier III Volatile Flux Chamber Test

treatment, may require more detailed information prior to design of such

actions. If management actions are selected, no further emissions

evaluation is necessary.

7.4 Tier III Volatile Flux Chamber Test

7.4.1 Volatile Emissions Laboratory Test Procedure Volatile Flux

Chamber (VFC)

A volatile flux chamber (VFC) test is available for Tier III evaluations of

volatile emissions from exposed sediment. Actual volatile contaminant

measurements may be needed in order to determine emissions under a variety of

site environmental and operational conditions for which the Tier II volatile

screens and models are not designed. The procedure involves loading dredged

material into a laboratory "flux chamber" and sampling air that has been passed

over the dredged material surface. A photo of the flux chamber is shown in

Figure 7.3. This procedure can be used to evaluate CDF operating scenarios, such

as crust management, for which the available models and predictive equations are

not designed.

The influence of dispersion as described in Section 7.5 on contaminant

concentrations should be considered in the Tier III evaluation of volatile

emissions.

Detailed procedures for conducting the VFC test are provided in Appendix F.

Figure 7-3. Photo of the volatile flux chamber device

7.4.2 Tier III - Volatile Emissions Decision

After consideration of the Tier III volatile emissions test and dispersion

information, one of the following conclusions is reached for volatile emissions

(Figure 7-2):

7-10

Chapter 7

Guidance for Evaluation of Volatile Emissions