4.4.2 Tier III - Effluent Water Quality Evaluation Effluent Elutriate Test (EET)

8-foot-long column as shown in Figure 4-3. Also, if WQS for total or whole

water concentrations are applicable, the column settling test is also required for

the Tier III effluent water quality evaluation. Since the column test is also used

for engineering design of the CDF for storage and solids retention (Section 4.1.6),

in most cases, the column test will be conducted even if no WQS exist for effluent

total suspended solids, turbidity, or whole water contaminants. Detailed

procedures for the LTCST are provided in Appendix B and also in Engineer

Manual 1110-2-5027 (HQUSACE 1987). A copy of EM 1110-2.5027 is also

included in Appendix K.

Figure 4-3. Photo of 8-inch settling column test

4.4.2 Tier III - Effluent Water Quality Evaluation Effluent Elutriate

Test (EET)

The Tier III evaluation of effluent water quality is based on a laboratory

elutriate simulation of the effluent discharge. This effluent elutriate test1 (EET) is

designed to account for the settling processes and geochemical changes occurring

The effluent elutriate test (EET) has been called the "modified elutriate" in earlier

literature to distinguish it from the "standard elutriate" test, which is applicable to open

water discharges. The term "effluent elutriate test" is used in this manual and in the ITM

for elutriate evaluations of CDF effluent, and the term "open water elutriate" is used in

the ITM instead of the term "standard elutriate" to describe the procedure for the open

water evaluations.

4-11

Chapter 4

Effluent During Disposal Operations