Permeability.

ETL 1110-1-158

28 Feb 95

(2) Permeability. A maximum allowable permeability is

sometimes specified for treated material by regulators. However,

permeability testing should be used with caution since higher

permeability is not necessarily related to leachability and the

placement of low permeability waste within a landfill may result

in ponded water within the landfill. The permeability of treated

material is generally measured with a flexible wall permeameter

using the test procedure described in ASTM D 5084-90. If

permeability testing is to be performed as part of a treatability

study, consideration needs to be given to the appropriate

confining pressure, gradient, and permeating fluid which will be

representative of field conditions.

(3) Durability. Durability tests are sometimes performed on

treated samples during a treatability study. These tests are

often used by comparing results with other test specimens (i.e.,

how many cycles can one mixture withstand versus a different

mixture). The test procedures specified for durability testing

of waste are entitled: Test Method for Determining the

Resistance of Solid Wastes to Freezing and Thawing (ASTM D 4842-

90) and Test Method for Wetting and Drying Test of Solid Wastes

(ASTM D 4843-88).

(4) Moisture-Density (Compaction Tests). Compaction tests

are run on treated and untreated material to determine compaction

requirements for treatability study test specimens.

Treated

material is often compacted to around 90 percent of maximum

density during a treatability study. It should be noted that

optimum water content for compaction is often not the optimum

water content required for hydration reactions. The two most

commonly used compaction test methods are the standard (ASTM D

698-91) and modified (ASTM D 1557-91) compaction tests.

(5) Index Properties. Various index properties may be

valuable in characterizing both untreated and treated material.

The following is a partial list of these tests. Additional

information on these test methods can be found in EPA/625/6-

89/022.

(a) Moisture Content (ASTM D 2216-90): Generally used as a

classification tool to determine the amount of free water present

in a material. This test is often used to determine if

pretreatment to remove free liquids is necessary. Moisture

content can also be used to determine how well a sample has been

homogenized prior to initial characterization testing.

(b) Apparent Specific Gravity and Bulk Density (ASTM D 5057-

90): Bulk density is used to relate weight to volume for

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