PERMFILE55696

• Permit No: C1981014
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 09 COMPARISON OF REFUSE AND SOIL SUITABILITIES
• Media Type: D
• Archive: No

• A Colorado study conducted by Vleck and Lindsay (1978) tested the
effectiveness of pyritic mill tailings materials to treat iron deficiencies and to
improve the physical properties of a highly dispersed calcareous, sodium
affected soil. They reported that the oxidization of pyrtes in the soil was
associated with a decrease in pH and dissolution of CaCO3 leading to the
eventual predpltation of gypsum created by the S04 generated by the
oxidization of the FeS2 in the pyrite and the Ca released by the acidification
of the unweathered geologic materials. This study documented that the
ultimate reduction in ESP corresponded to the relative size of the pyrite, with
smaller fractions being much more reactive than the coarse size fractions.
In a 60 day greenhouse experiment, the ESP was decreased between 38 and
83 percent depending on the particle size of the pyrte involved. These
authors suggested additional testing of pyrites as a means of correcting
problems normally associated with iron deficient sodium affected soils be
conducted.
RESULTS OF SOUTHFIELD MINE SOILS AND REFUSE SAMPLING
During 1979 and 1980 Dorchester Coal Company, the previous owner of
the Southfield Mine, sampled various areas to be disturbed by proposed
mining activities. All of these data were submitted to the CMLRD in the
original Dorchester Permit. A total of 42 soils samples were collected during
these efforts. Examination of the data collected from the refuse pile area
• reveal that eight soils pits were dug in this area. The soil depths and
associated rooting depths from these pits are summarized in Table 3.
Using these data, the average depth of soil for the Southfield Mine refuse
area is 39.9 inches, although 25 percent of the area had soils less than 14
inches deep and the average depth on 50 percent of the area was 20.5
inches.
Several of the Southfield Mine soil samples were contaminated with old
waste coal generated by previous mining activities. Due to the similarities of
the waste coal mixed with the topsoil and the refuse pile materials a
comparison was made of the topsoil samples based upon the presence of
waste coal to determine what 'rf any adverse impacts the addition of waste
coal has on the properties of the topsoil.
Upon correlating the soil sample locations presented on the original
Dorchester Coal Company Soils Map, Map No. Dor-S-S-1, wlth the locations
of past mining activity the approximate age of waste coal deposltion can be
determined for 5 of the 8 samples contaminated with waste coal. Samples
21, 22 and 23 taken from soil plt no. 11 correspond to the location of the old
Black Hawk Mine. According to the information complied by Energy Fuels,
the Black Hawk Mine operated in the Jack O'Lantern Seam from 1935-37.
Therefore, at the time these samples were collected the coal waste materials
had been present for approximately 42 to 44 years. Samples from soil pits
1 and 2 are dosest to the old Manley Mine, that operated in the Manley Seam
from 1935-1951, so these soils had been contaminated with waste coal for
• a period of approximately 28 to 44 years. The locations of three of the
Dorchester samples are not shown on the soils map. However, since these
three coal contaminated samples were the earliest samples collected by
Dorchester, and due to the locations of other samples collected, lt appears
20