2013-06-03_GENERAL DOCUMENTS - C1981014

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Dan Hernandez Page 7 June 3, 2013 As further evidence of the lack of viable water supply resources in the groundwater formations near the Southfield Mine, the following excerpt has been copied from pages 2.04.7 -5 and 2.04.7- 6 in the PAP. "In summary, there are no stratigraphic units in the mine, loadout, or adjacent areas which can be considered as aquifers based upon the definition of Rule 1.4 (14). A number of the stratigraphic units do have the capability to store and transmit water. However, these capabilities along with the potential for beneficial use are limited by lack of lateral continuity, limited areal extent and relatively low horizontal and vertical hydraulic conductivities. Groundwater resources generally occur as isolated perched reservoirs either within the stratigraphic sequence where favorable localized lithologic and recharge characteristics exist or where the stratigraphic sequence has been modified by underground mining. Underground mining creates large reservoir areas where variances in hydraulic pressure appear to stimulate groundwater inflows and flooding of the abandoned mine workings. Some conclusions have been made with regard to the rate and direction of groundwater flow within the Vermejo Formation inside the permit area of the Southfield Mine site. In the 1987 Southfield Mine Water Rights Engineering Report the authors state that "the direction of groundwater movement can be predicted by contouring water level elevations in observation wells and drawing groundwater flow lines at right angles to the contour lines. Water levels in the five currently operational monitor wells penetrating the coals have consistently and continuously shown groundwater movement to the northeast, somewhat parallel to Newlin Creek and Magpie Creek drainages." "... The monitoring wells reveal water levels in the Pine Gulch, Jack (Jack O'Lantern) and Red Arrow coals, all within the Vermejo Formation." The DRMS has a different interpretation of the ground water flow direction and movement. The problem lies in that the water levels used to draw the groundwater contours shown on Figure 5 of the 1987 report are actually potentiometric head levels as opposed to static water levels, and if contoured would then represent a potentiometric surface for wells completed in the coal zones. The monitoring wells used in the analysis were constructed with the perforated interval in the target coal zone which ranges in thickness from 4 -8 feet. Most of the well screen lengths used are 30 feet, so the strata either immediately above or below the coal seam was also included in the screened interval. It is likely that the majority of water contributed to the wells is from the Red Arrow and Dirty Jack O'Lantern coal seams given the isolated occurrence of perched groundwater in the Vermejo Formation. In some instances mapping of a potentiometric surface provides useful information but that is not the case for this particular study area given the low permeability, interbedded stratigraphic sequences within the Vermejo and the low horizontal and vertical hydraulic conductivities. The level to which water will rise in a properly constructed well completed in these coal zones is primarily the result of the amount of pressure or thickness of the overlying strata (overburden) and the depth of the well. To illustrate this point, DRMS constructed a cross - section labeled A -A' utilizing the data taken from Table 2 and Figure 5 of the 1987 Southfield Mine Water Rights Engineering Report. Cross - Section A -A' and Figure 5 are provided in Appendix C. Three other cross - sections are incorporated into Appendix C as follows; Figure 9 of the 1987 report, "Generalized Cross Section Depicting Well Completions" is included because it provides a good reference for the location of mine entries, coal seams mined,