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December 07, 2017 Page 1 <br /> 1.0 INTRODUCTION <br /> Natural Soda, Inc. (Natural Soda) commissioned Agapito Associates, Inc. (AAI) to take <br /> quarterly logs of its time domain reflectometry (TDR) surveys for monitoring subsidence from <br /> monitoring well (SMW) 3M TDR. This report presents the TDR surveys logged on December 1, <br /> 2017, for Cables #2 (Kyle) and #3 (Matt) from SMW 3M TDR. The completion diagram of <br /> SMW 3M TDR is shown in Figure 1 for reference. <br /> 2.0 TDR READINGS <br /> The surveys were taken with AAI's Campbell Scientific, Inc. TDR 100 instrument. A <br /> propagation velocity factor (vp) of 0.87 was used in the data processing and 2,048 data points <br /> were recorded along each cable. A waveform average of 64 points was used to eliminate <br /> background noise. Cables#1 (Blank) and #4 (Kyle2) were corrupted during installation and are <br /> not used for monitoring. No readings were taken in these cables. <br /> 3.0 WAVEFORM ANALYSIS AND RESULTS <br /> TDR waveform histories for Cables#2 and #3 are shown in Figures 2 and 3, starting with <br /> the original waveforms from December 10, 2003. Expanded waveforms are shown in Figures 4 <br /> and 5 for Cables #2 and #3, respectively. The close-up figures highlight the zone of interest <br /> between 880 and 1,960 ft deep, including the B Groove aquifer located between 1,566 and <br /> 1,588 ft. <br /> The December 1, 2017, survey indicates that no significant ground movement has <br /> occurred around SWM 3M TDR since the cables were originally installed. This is evidenced by <br /> the constant waveform history in Cable#3 (Figure 3). <br /> Cable#2, parallel to Cable #3, shows evidence of water infiltration into the cable starting <br /> soon after installation. This is evident in the February 17, 2004, waveform, which shows the first <br /> signs of a distorted signal beyond a depth of approximately 1,745 ft. Water causes distortion by <br /> changing the dielectric constant of the insulation material in the cable and, thus, the propagation <br /> velocity of the reflected signal. Subsequent surveys in Cable #2 show a gradual rise in the <br /> distortion elevation, symptomatic of water propagating up the cable under hydraulic pressure <br /> from a leak originating at or near the end of the cable. Similar to the most recent results, the <br /> December 1, 2017, survey indicates that water has infiltrated the cable up to a depth of about <br /> 1,438 ft. <br /> If the cable is not mechanically deformed by ground movement, the signal distortion <br /> caused by water infiltration superimposes on the original waveform. This appears to be the <br /> process occurring in Cable #2. Cable deformation, including shearing or breakage, normally <br /> produces a sharp "spike" in the waveform, which is expected to be recognizable even through the <br /> distortion caused by water infiltration. Cable #2 shows no obvious signs of localized damage, <br /> suggesting that significant ground movement is not occurring. This is consistent with the results <br /> of Cable #3. Water infiltration is likely to continue in Cable #2 and may eventually render the <br /> cable inoperative. <br /> Agapito Associates, Inc. <br />