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IMMENNINNINEW <br /> A Natural Soda LLC 2017 Project Status Report & Annual Plan of Development <br /> 4.4 Geotechnical Program <br /> NS currently monitors two time-domain-reflectometry (TDR) subsurface-subsidence <br /> monitor wells, the 4A-5M and 3M-TDR. There has been no indication of surface or <br /> subsurface subsidence near the 4A-5M or 3M-TDR wells since installation. One of the <br /> TDR cables in the 4A-5M well is showing evidence of water infiltration. Two of the four <br /> TDR cables in 3M-TDR subsidence well were corrupted during installation, in 2003, and <br /> not operable. In addition to the monthly NS readings, the installation contractor also <br /> collects data quarterly. <br /> 4.4.1 Subsurface Subsidence Geophysical Logging <br /> NS conducted routine, EPA mandated, subsurface subsidence logging, in their DS-5 <br /> (2010-26-198-1C) subsurface subsidence monitor well on April 25, 2017. This <br /> subsurface subsidence logging was required due to the 14H production well having <br /> reached a mining interval recovery percentage of 50%. No subsurface subsidence was <br /> observed. <br /> NS conducted final, EPA mandated, subsurface subsidence logging, in their BG-8 (DS <br /> 4, 10H-C) subsurface subsidence monitor well (SSMW) on May 3, 2017. The BG-8 <br /> served as the SSMW for the NS 10H an 11H mining intervals. The logging was <br /> performed prior to the P&A operations of the 11H production well pair P&A as required <br /> by EPA, and the P&A of the BG-8 (DS-4, 10H-C) well. No subsurface subsidence was <br /> evident. <br /> 4.4.2 Surface Subsidence Monitoring <br /> In June 2017 a new 17H SSM was installed above the proposed 17H lateral wellbore. <br /> This installation was performed in compliance with requirements contained within the <br /> EPA Underground Injection Control (UIC) Permit # C030358-00000. <br /> A surface subsidence survey of 15 SSM locations was conducted in June and August of <br /> 2017. Two SSM's, the CP6 and CP8 were not surveyed in 2017. The mining intervals <br /> that are located below these two surface monuments have been retired for over five <br /> years and do not require continued surveying. A review of the 2017 survey indicated no <br /> surface subsidence. Results of the 2017 SSM Survey are shown in Table 5 below. <br /> 4.5 Water Well Pumpage <br /> In 2017, approximately 106.9 million gallons of water was pumped from water supply <br /> wells WSW-2, WSW-3, and WSW-4 with an average of 203.3 gpm. The total pumpage <br /> from WSW-2 was 14.8 million gallons, WSW-3 was 40.7 million gallons, and the total <br /> pumpage from WSW-4 was 51 .4 million gallons. <br /> DAUB&ASSOCIATES. INC. • . .- 20 January 2018 <br />