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Ms. Barbara Coria November 9, 2015 Page 2 As part of the mining operations at the Nahcolite Mine, there are extensive monitoring operations and studies with respect to surface and subsurface subsidence and other potential impacts on structures in the vicinity of the Nahcolite Mine. Figure 1 shows the lease area with the utilities that cross the lease area and surface structures. Figure 2 shows in more detail the utilities and structures in the immediate vicinity of the plant and wellfield. Of interest are the "structures located within two hundred (200) feet of the operation or affected land." On both Figure 1 and 2, the white dotted line indicates the border 200 feet from the operation, in this case, the lease boundary. In some locations, the white line is 200 feet from wellheads that lie outside the lease area. Of note is the fact that there are no buildings (other than Natural Soda's plant and associated buildings) within the lease area or within the 200 -foot buffer around the lease area. Of interest are buried gas pipelines, above -ground electric transmission lines and power lines, some of which are owned by Natural Soda and some of which are owned by others. Also shown on the figures is the proposed 20+ -year mining area. This area consists of a small percentage of the lease area. There are no long-range plans for developing outside the 20 -year mining area at this point in time although the areas where attractive nacholite is are limited to a narrow area trending to the northwest from the 20 -year mine area as shown in the yellow zone in Figure 1. Figure 2 shows the location of the historical solution mining, the proposed wells to be drilled in the near future and the location of historical surface subsidence monitoring locations above the historically mined areas. Surface and subsidence monitoring has been ongoing since 1997. Table 1 shows the historical data from the 18 surface subsidence monitoring locations. This data has been submitted to the United States Bureau of Land Management (BLM) semi-annually (once every two years). There is a shift in the data due to a change in reference point. The explanation of this shift is explained in the footnote to Table 1 which is reproduced below: SSM surveys were begun in 1990 and were historically collected by Midford Coolbaugh of Shale Country Surveying. Coolbaugh collected SSM surveys until 2008 when he moved out of the area. The Coolbaugh survey elevations are generally consistent from year to year and reflect no surface subsidence between 1990 and 2008. In 2011 Richard Bullen with DR Griffith & Associates Inc. (DRG) was contracted for the NS surveying operations. A review of DRG's survey data and comparison to Coolbaugh's survey data revealed discrepancies in well locations and well elevations. These discrepancies are attributed to differences in technology, equipment type, NAD conversions, and surveyor datum. Coolbaugh surveys were done by differential leveling using NAD29 (NGVD 29) datum. DRG uses NAD83 (NAVD88) datum. In general, the DRG SSM surveys were noted to have an elevation that was approximately 2.4 feet higher than the Coolbaugh SSM surveys. The DRG updated survey data was used to generate a comprehensive survey database. Accurate elevation data is vital for monitoring groundwater,establishing stratigraphic tops and controls, and topographic considerations such as pad/pipeline construction and reclamation. Agapito Associates, Inc.