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detected easily. An easier way to detect neutrons is to thermalize them, (ie. slow them down by collisions with other atoms). The element that most effectively thermalizes neutrons is hydrogen. Since hydrogen is a major component of water, Troxler uses a slow neutron detector to correlate the measured neutrons to the moisture in a sample area. Since hydrogen is a common component of many common materials, the moisture readings given by the Troxler can be greatly affected by the material being tested. Materials with high levels of hydrogen such as hydrocarbons can be measured if the hydrocarbons remain in a constant ratio with the other elements in the material. Problems arise when a hydrocarbon material such as coal or carbonaceous shales are randomly distributed throughout the sample being measured. Because of the randomness of hydrocarbon distribution in the coal refuse pile, the Troxler meter cannot be calibrated or counted on to provide consistent moisture readings. The inability of the Troxler meter to read moisture in coal refuse does not affect its wet density measurement capabilities. In more uniform soils the meter measures the wet density of a material, and then measures the moisture. The microprocessor then subtracts the measured moisture out of the sample and reports a dry density. It can also compare the dry density to an operator entered optimum density value to give compaction values as a percent of proctor. To determine compaction in the coal refuse pile, only the wet density reading from the Troxler meter is used. The moisture values are determined in the laboratory by use of a moisture oven following ASTM D-2216-92. The basic question raised was whether the bulldozer excavated pits caused any bias in the compaction testing of the refuse pits. In response to this question Western Fuels engaged in a pilot test program to test for any bias caused by the bulldozer excavation method. The test pit location, (located on map 1) was chosen to represent an area of the pit that would be one of the least compacted areas 3.