NS 2023 Annual Report For EPA

• IBM Index Class Name: Hydrology
• Doc Date: 8/28/2025
• Archive: No

Natural Soda LLC 2023 Project Status Report & Annual Plan of Development
24 January 2024
Table 5: 2023 Surface Subsidence Monuments (SSMs) Surveyed Elevations

Surface Subsidence
Monument
(SSM)
Initial
Monument
Elevation
(ft. AMSL)
2023
Monument
Elevation
(ft. AMSL)
Elevation
Change
(ft.)
CP SODA BM 6634.90 6634.90 0.00
CP CENTER SSM 6658.99 6658.93 -0.06
CP NORTH SSM 6639.21 6639.20 -0.01
CP EAST SSM 6669.52 6669.31 -0.21
CP SOUTH SSM 6683.84 6683.71 -0.13
CP WEST SSM 6669.77 6669.80 0.02
CP 6 SSM 6682.88 6682.92 0.04
CP 7 SSM 6706.52 6706.44 -0.08
CP 8 SSM 6691.65 6691.63 -0.02
CP 10 SSM 6687.41 6687.32 -0.09
CP 11 SSM 6653.71 6653.60 -0.11
CP 12 SSM 6702.11 6702.06 -0.05
CP 13 SSM 6725.22 6725.20 -0.02
CP 14 SSM 6758.42 6758.36 -0.06
CP 15 SSM 6624.65 6624.61 -0.04
10H SSM 6712.95 6712.51 -0.44
11H SSM 6705.81 6705.16 -0.64
12H SSM 6695.86 6695.36 -0.50
12HA SSM 6661.41 6661.31 -0.10
13H SSM 6684.47 6683.91 -0.57
14H SSM 6675.20 6674.79 -0.41
15X SSM 6694.41 6694.33 -0.07
15H SSM 6702.35 6702.24 -0.10
16H SSM 6713.03 6712.99 -0.04
17H SSM 6719.06 6719.04 -0.01
17HA SSM 6738.67 6738.51 -0.16