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I~i AL Dcn h~th ?w5 January 4, 1983 _ pace 2 R~-loses As per our discussion December 30, 1962, the overburd=_n samples will be analyzed for the par-meters listed below with the following suspect levels. parameter Suspect Level _ PH less than 5 or greater than 9 Electrical conductivity greater than 12 millirnoh5/cm Sodium Adsorption Ratio greater than i5 Selenium (if pH is greater than 8.4 grea than-2-ppm Boron (if pH is greater than 8.4) greater than B ppm Lead (if pH is less than.5 or greater than 10) greater-than 20 ppm Remedial Measures If suspect levels of the parameters to be analyzed are encoun- tered, the Division will be notified upon receipt of the analyses and i remedial measures taken. Usually, overburden drilling is accomplished at least two waeks prior.to mining and laboratory analyses can be obtained in one week, and possibly two to three days if requested. Therefore, if suspect levels of toxic materials are detected, the following remedial measures will be undertaken folltnring consultation with the Division. 1_ An assessment of the suspect level will be conducted to determine if mixing of the suspect material with acceptable material will provide an adequate solution. Dollhopf, et. al. (1981)~found that mixing of Fort IInion Formation spoil by a dragline operation pro- vided the following results: "when the problem material constituted less than five percent of the total overburden volume, such material gas essentially not detecable in the spoil pile. When the problem material constituted 5 to 158 of the overburden volume the material often could not be detected in the spoils 508 of the time; although the volume of the problem material detected in the spoils was generally less than that found in overburden, 'indicating partial dilution occurred. R'hen problem material exceeded 158 of the overburden volume it eras always found in the spoil pile, generally to a smaller extent, again ~. ~ indicating partial dilution." ~ The mixing concept will likely be more useful at Colowyo ~~~ - - than in a dragline operation, because the spoil material may be mixed over a much larger area, both-vertical and horizontal. If suspect ._. material is Encountered, mixing will be analyzed with res_a2ct to the then present dumping ~ronfiguration.