2011-08-04_ENFORCEMENT - C1981008 (2)

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of the intermixed B horizon materials as well as the B lift in general. From the information available within the permit, it appears DRMS 's authorization allowing the operator to salvage such a large proportion of the C horizon materials as a part of the B lift, was based on a total of 2 pre - disturbance sample points taken from the Order 1 Soil Survey. It is recognized that it may be possible that a small portion of the C horizon materials (particularly the upper few inches) may be suitable for use as a subsoil in reclaiming prime farmlands, although the limited sampling data available does argue to the contrary. It is clearly evident that most of the C horizon is not suitable, and scientific reasoning would dictate the need to conduct fairly extensive sampling of all C horizon materials considered for use in mixing with the B horizon materials, to ensure doing so would not minimize the opportunity to achieve the post mine yield potential of the prime farmlands reclaimed. Based on our review, considering the very limited number of samples taken for demonstrating the suitability of the C horizon materials approved for use by DRMS, OSM cannot accurately and reliably determine the suitability of even the upper few inches of the C horizon. To do so to a degree that would provide a technically reasonable amount of data to lead the decision maker to justify the practice of mixing the C horizon with the B horizon to the extent approved, would likely require in excess of 20 sample points to be taken on the post -2008 Morgan property, rather than the 2 used for this confirmation of quality. In addition to relying on an insufficient number of samples from the C horizon to be provided in advance of approving the practice of extensively mixing the C horizon with the B horizon, DRMS appears to have authorized WFC's proposal to affirm the suitability of this subsoil mix by way of sampling the soil medium after it had been respread over the regraded spoil during reclamation. This after -the -fact practice, should it be proven to have negative consequences to restoring cropland yields, minimizes any practical and/or cost effective opportunity to mitigate resulting undesirable impacts to the Morgan property. In a field inspection report prepared by DRMS dated March 29, 2011, the following statement. appears: "On the slopes of the Lift B pile, angular blocks of sandstone and chunks of calcareous material are not uncommon. The source of these blocks appears to be zones of cemented sand and calcareous zone found within the in -situ B subsoil. " Use of the phrase `B subsoil" is presumed to be referring to the Lift B salvaged materials, about 50% of which is comprised of C horizon soils. The information provided in the inspection report supports the sample data that is available, strongly implying that excessive rock and calcium carbonate materials (i.e. unsuitable materials) are present within the Lift B stockpile, thus increasing the potential of negatively compromising cropland yield on the reclaimed prime farmlands. OSM's review has determined that the practice of significantly mixing C horizon materials of inadequately proven quality with prime B horizon soils for creating the B lift substrate for prime farmland reclamation, contravenes the requirements at 2.06.6(2)(d), 2.06(4)(c), 4.06.2(3), 4.25.3(2), 4.25.4(4). As discussed above, a significant portion of the Zone 4 (post -2008) B horizon soils are being salvaged and are approved for use iri reclaiming Zone 3 (pre -2008) prime farmlands. This of course means these B horizon soils will not be available for use at the location from which they came (Zone 4), thereby potentially increasing the risk that these soils will not be needed to restore the yield potential of the prime farmlands in Zone 4. Instead of receiving the balance of the 13 horizon soils salvaged from Zone 4, which had been previously identified as prime 13