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1 <br />• <br />Page 2 <br />Brian Munson <br />March I8, 1981 <br />Chen 6 Associates' report presents specific foundation preparation, key way and <br />cut-off construction recommendation for each of the five embankments. In <br />addition, the consultant recommends the installation of survey monuments and <br />ground water piezometers to measure consolidation of the sub-soils and its <br />affect upon the structures. <br />Based upon the data presented by Chen & Associates, I agree with their concerns <br />and monitoring recommendations. The calculated factors of safety for the <br />embankment's slopes are adequate to satisfy the 1.5 minimum requirement for all <br />embankments except the downslope face of pond #5, which achieved a factor of <br />safety of 1.45. In light of the specific method used by the consultant in <br />calculating the factors of safety, I believe that a1Z of the factors of safety <br />should be considered adequate and I recommend approval. in the short term, <br />however, due to the saturation of foundational sub-soils, the slopes of <br />embankment #1 are substandard. The consultant's calculations project a short <br />term construction safety factor of only 1.2 for the slopes of embankment #I. <br />Consolidation of these sub-soils, due to the imposition of the weight of the <br />embankment, are projected to improve material strengths of the foundational <br />soils, resulting in an eventual safety factor in excess of 1.5. <br />For this reason I believe it particularly critical to assure the applicant's <br />complete conformance with the inspection and certification requirements of <br />Rule 4.05.6(7) and the examination and reporting requirements of Rule 4.05.6(11). <br />Furthermore, in this particular case, because of the design consultant's specific <br />concerns, I recommend the requirement of the piezometer and survey monument <br />installations recormnended in Table III of appendix Q. Reports submitted by <br />the applicant, in conformance with the requirements of Rule 4.05.6(11), should <br />include the results of observations and monitoring of those survey monuments <br />and ground water piezometers. <br />/k <br />CC: F. Banta <br />