Table 6. Data Requirements and Testing Standards for Soils and Dredged Material

ERDC TN-DOER-R6

December 2004

1993). This increased water content results in potentially significant initial short-term quantities of

leachate. However, this leachate flow will decrease greatly as the dredged material consolidates and

seals the bottom of the fill.

Quality of leachate Leachate provided by dredged material within CDFs may contain more

suspended and colloidal materials than landfill leachate. Special consideration must be given to the

operation of the leachate collection system and the selection of the system filter material overlying the

drainage layer to ensure that it will not become clogged by suspended and colloidal materials

contained within the leachate.

DATA REQUIREMENTS AND TESTING

Soils and Dredged Material. Design of CDF soil and dredged material liners requires testing of

individual soils and sediments for determination of optimum particle size, Atterberg limits, compactive

efforts, moisture content and dry unit weight, hydraulic conductivity, and permeability. Data

requirements and testing standards for soils and dredged materials are provided in Table 6.

Table 6

Data Requirements and Testing Standards for Soils and Dredged Material

ASTM Procedures and

Comments

Requirement

References

Unified Soil Classification

ASTM D2487-00

Used to classify engineering properties of soils based

System (USCS)

(ASTM 2000a)

on particle size and organic matter content.

Atterberg Limits

ASTM D4318-00

Provide water contents at which a fine-grained soil or

(ASTM 2000d)

sediment changes from a semisolid to a plastic solid

EM 1110-2-1906

and from a plastic solid to a semiliquid.

(USACE 1970)

Ideally, optimum compactive effort should be evaluated

Compactive Effort

in actual field conditions through a series of test

sections. However, the cost of determining design

parameters in this manner is often prohibitive (Qian

1995). Most design criteria are thus developed from

laboratory tests employing methods of compaction that

best match actual field compaction effort (Qian 1995).

ASTM D698-00a

Standard Proctor Test

Represents an average compactive effort delivered to

soils in the field.

(ASTM 2000g)

Represents maximum compactive effort delivered to

ASTM D1557-00

Modified Proctor Test

soils in the field.

(ASTM 2000h)

Recognizing that the greatest hydraulic conductivities

Daniel and Benson

Reduced Proctor Test

would be realized in soils and dredged material

(1990)

experiencing the least compactive effort, Daniel and

Benson (1990) developed an altered standard Proctor

procedure called a "reduced" Proctor test. In this case,

only 15 drops of the hammer per lift are used instead of

the standard Proctor test use of 25 drops. This reduced

compactive effort is believed to represent the minimum

level of compaction for a typical soil or sediment liner

(Qian 1995).

(Continued)