PERMFILE138867

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 56 Evaluation of B-Seam Impacts on Refuse Pile Leachate
• Media Type: D
• Archive: No

chewically analyzing the decanted fluid. Details of the test procedures are
• provided in Attaclunent 2.
1'l~e individual B seam test results were averaged on the basis of estimated
percentage of the remaining refuse pile waste volume as follows:
1. The average for mine develolnnent wastes was obtained by computing a
weighted average for tl~e data obtained from Drill Ilole 3. '1'lie weig}iC %
assigned to each analysis was the Length of core Dole interval tested
divided by tl~e total length of all intervals tested. In the case of rJ~
pFl, the weighted average was performed for hydrogen ion concentration I`3
and stated in terms of pll. Tlie average pll value does not account for
buffering by alkaline materials, wlrictr w111 result in a more alkaline ~.
pH than that calculated.
2. The average for the gob materials was obtained by taking ttie
arithmetic average of the eleven composite samples taken from 6 drill
holes witktirt 10 feet of the coal seam.
3. The overall average for B seam materials was computed by taking the
weighted averages of the values determined in 1 and 2 above raitlr
weighting assigned as the ratio of mine development or gob waste
divided by the total estimated volwne of B seam waste materials.
• Tlie average and range of lcacliatc test results for the B scam refuse are
summarized in Table 3.
Table 4 shows rile calculated
previously submitted F seam leachate
results. The allowable leachate
nitrate, and boron on the basis of
Attachment 1 and selection of mote
"typical values" selected previously
valid after review of the additional
allowable leachate concentration and the
results in relation to the 6 seam leachate
concentrations were modified for iron,
our review of Nortli Fork quality data in
appropriaCe "typical values". A11 other
for the F seam Adequacy Responses remained
data.
With the exception of copper, manganese, lead, pll and zinc, the average
leaclrata test results Far the B seam materials are within or lower than the
previously approved F seam leachate [est results. AL1 8 seam leach test
results meet the calculated allowable leachate concentration. Boron, manganese,
pll, sulfate and TDS fo[ the 8 seam leachate tests meet Nortlr Fork ISS without
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