2019-08-26_REVISION - M1973007SG

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ATTACHMENT A The following stipulations need to be addressed through the submittal of a technical revision (TR) and requisite $216 fee within 60 days of the date of this letter: A. A signed structural agreement for the Fountain Mutual Ditch was not provided during the SO-02 process. The engineering evaluation provided on August 14, 2019 does not meet the DRMS criteria in Rule 6.5 and Section 30 of the Policies of The Mined Land Reclamation Board (MLRB Policies) for Factors of Safety for Slope Stability/Geotechnical Analyses. Please provide slope stability geotechnical analyses for the four cross-sections shown in Attachment B meeting the MLRB policy under worst case mine plan conditions by the 60- day deadline. B. Please address the following with respect to adjacent roads: i. The July 26, 2019 Figure I cross-section submitted for the Milton E Proby(4.5:1 pit slope 463'away)engineering assessment is skewed,thereby not showing the steepest slope(s). The DRMS is also uncertain as to whether the digital elevation model (DEM) used in Google Earth to generate the profile is current. Please resubmit the profile with the cross-section perpendicular to the slope and provide some evidence the DEM is current, or use a survey cross-section. Please be aware if any of the slopes are steeper than 311:1 V, the DRMS may require a slope stability geotechnical analyses for this area meeting the MLRB Policy, Section 30. ii. The July 26, 2019 Figure 2 cross-section submitted for the Bradley Road roundabout engineering assessment indicates the slope is 17.5:1 and 288' away. DRMS field observations suggest this slope is much steeper,causing uncertainty as to whether the DEM used in Google Earth to generate the profile is current. Please provide some evidence the DEM is current or resubmit the profile with the cross-section using a survey cross-section. Please be aware if any of the slopes are steeper than 3H:IV, the DRMS may require a slope stability geotechnical analyses for this area meeting the MLRB Policy, Section 30. iii. The July 26, 2019 Figure 3 cross-section submitted for Bradley Road engineering assessment is skewed, thereby not showing the steepest slope(s). The DRMS is also uncertain as to whether the DEM used in Google Earth to generate the profile is current. Please resubmit the profile with the cross-section perpendicular to the slope and provide some evidence the DEM is current,or use a survey cross-section. Please be aware if any of the slopes are steeper than 3H:IV, the DRMS may require a slope stability geotechnical analyses for this area meeting the MLRB Policy, Section 30. iv. The July 31,2019 Figure 1 cross-section submitted for the Bradley Road and Cassidy Street engineering assessment on indicates the slope is 12.75:1. DRMS field observations suggest this slope is much steeper,causing uncertainty as to whether the DEM used in Google Earth to generate the profile is current. Please provide some evidence the DEM is current or resubmit the profile with the cross-section using a survey cross-section. Please be aware if any of the slopes are steeper than 3H:1 V, the DRMS may require a slope stability geotechnical analyses for this area meeting the MLRB Policy, Section 30. Page 3 of 3