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' Page FOUI i • <br />Preliminary Adequacy Review <br />Grand Mesa Coal Co. - Red Canyon nfine <br />May 8, 1981 <br />2.~ One representative site witlzin both the "IJ" portal yard disturbance <br />~ area and the sediment pond disturbance area should include an analysis of <br />each horizon as required by 2.09.9(2)(b). At least two representative <br />samples, with analyses by horizon, should be taken from the previously <br />undisturbed area to be affected by the refuse pile. One sample should <br />correspond to the more well developed soil, with a fairly thick A horizon, <br />and the other should correspond to the soils with thin A horizons. The <br />applicant should estimate the approximate q of the deeper soils (swales <br />and toe slopes) and shallow soils (ridges and steeper slopr_s) and base the <br />available topsoil calculation on this. 1f the shallow soils are underlain <br />J by coarse rock material, or bedrock, with essentially no horizonal development, <br />this should be indicated. The analyses should .include plf, Electrical <br />Conductivity, Sodium Absorption Ratio and Textural analysis. Zt is not clear <br />whether samples were taken in the old strip pit overburden material within <br />the proposed refuse disposal site (see comments 3 and 9 below). Since <br />this material is to be used as cover for the refuse pile, the same types <br />of analyses requested for topsoil would be required. Sampling by horizon <br />would not apply. If samples have been taken in the old overburden, the <br />locations should be indicated on the soils map. <br />3. Sites SSl through SSIp could not be located on the soils map. Sites <br />Tl and T2, O1 through Olp and RI and R2 were shown as sample areas or mapping <br />units on the soils map - not as individual soil .samples as indicated on <br />page 67 of the Soil Sample Analysis tables. site Rj could not be Iocated. <br />These apparent discrepancies should be clarified. <br />4. Sites R-1, R-2 and R-3 exhibit extremely high SAR values. Specific <br />information regarding the sampling methods and location should be provided. <br />Such high levels of sodium would effectively prevent vegetative establish- <br />ment. The applicant should indicate if these samples are from the material <br />proposed as cover for the refuse pile. Zt is stated on page 69 that these <br />materials should be buried at a depth of 4 feet, along with the acidic Sl <br />and s2 material. The applicant should determine the volume of this toxic <br />material and indicate how it will be isolated Fran plant growth medium. <br />5. The applicant proposes, on page 68, to salvage the top 6 inches of <br />topsoil in the refuse disposal area and the top 6 to 12 inches in the aze2 <br />of the proposed sediment pond. Due to the limited topsoil available for <br />revegetation, the operator should attempt to salvage all available, suitable <br />topsoil, taking advantage of Localized depositions of deeper soil. <br />6. Rule 2. 09,9(1)(d)(ii) rrequ.i.res a narrative or table. adrlress.ing the suit- <br />ability of each major soil hnr,izon as a plant growth media. This summary <br />should be drawn frum the analyses to be run on samples requested in comment <br />2 of this section, and sl>ould be based on fertility levels, texture, <br />salinity, sodium, and any potential toxic properties of the various soil <br />horizons. <br />