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Parameter selection
<br />Overburden information from the six Phase I sample sites was evaluated and summarized to
<br />select and justify the proposed chemical and physieai parameter list f ~ the PF~a se II
<br />/
<br />extract
<br />The Phase I overburden samples were tested for paste pH, paste
<br />sampling program.
<br />)
<br />EC, saturation percentage, sodium adsorption ratio (includes water soluble sodium,
<br />
<br />calcium, and magnesium), acid base potential, ammonium oxalate extractable molybdenum,
<br />DTPA extraetab to cadmium, copper, iron, manganese, nicker, lead, and zinc, hot water
<br />extractable boron and selenium, and particle size (includes percent sand, silt, and clay).
<br />~~ Four constituents (total combustible solids, nitrate-nitrite, arsenic, and mercury) listed
<br />-~ - on the Colorado Water Quality and Overburden Geochemistry Guidelines (1982) were not
<br />~~ ~ ~~ included on the Phase I parameter list.
<br />
<br />
<br />P
<br />b
<br />d
<br />'
<br />i 11
<br />N~,~
<br />ea
<br />o
<br />x core holes were compared to
<br />y
<br />s most
<br />The Phase I analytical results from the s ~/
<br />recently approved overburden-spoil suitability list presented with the Nucla East permit, ~~~„ (,
<br />W
<br />Tab 6, Attachment 6-1, Table 6-1-3 (Peabody Coal Company, 1988). The number of samples ~yr
<br /> 4
<br />~
<br />which exceeded suitability levels and the maximum constituent values by core are presen _
<br />t
<br />in Table 1. ~~ ~
<br />((,~
<br />~
<br />-*~
<br />Unsuitable levels were recorded for six constituents, pH, acid base potential, iron,
<br />manganese, boron, and clay. Extremely acid soil reaction, acid base potent ill values with
<br />more than a five-tan calcium carbonate per 1,000 tons of spoil deficit, and boron values
<br />~ ---~
<br />greater than 5 ppm were dominantly associated with the Lennon coal seam. jlay percentages
<br />greater than 50 percent were associated exclusively with shale strata overlying the Lennox
<br />coal seam and also with the 1.5-foot thick shale zone directly overlying the Wedge coal
<br />seam. Peabody suspects the exce ssiv iro jand manganese values are attributed to the eo re
<br />samples having been contaminated by dri lld ri 11 st~~ I (,
<br />No unsuitable concentrations were recorded for selenium, zinc, lead, nickel, copper,
<br />cadmium, molybdenum, or sodium adsorption ratio. The maximum values recorded for lead,
<br />~ selenium, cadmium, and sodium adsorption ratio are an order of magnitude less than the
<br />threshold limit, while values for zinc, nickel, copper, and molybdenum are about two to
<br />five times less than threshold limits. No unsuitable values were recorded for salinity or
<br />saturation percentage; however, maximum values were less than two times the t/h reshold
<br />value. Glcie~i-~~%•--~
<br />i,:..,t ~ ~~~
<br />~~ ~
<br />h`~~
<br />~N
<br />5 ~/
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