2014-03-03_REPORT - M1988112

• Permit No: M1988112
• IBM Index Class Name: REPORT
• Doc Date: 3/3/2014
• Doc Name: Detailed Inspection Report
• From: DRMS
• To: McClure & Eggleston, LLC / Edwin J. Lobato, Esq.
• Email Name: WHE
• Email Name: GRM
• Media Type: D
• Archive: No

6.3 Recommendations for Additional Studies to upgrade facility performance
forextreme flood events ........................................................... .............................58
6.3.1 Design of an Auxiliary Overflow Structure at the Drop Structure ............58
6.3.2 Design of a Controlled Overflow from Ditch to Impoundment ................59
6.4 Recommendations for additional inspections and monitoring .. .............................59
7.0 REFERENCES ..................................................................................... .............................60
LIST OF TABLES
Table 1
Elevation- Area - Volume Relationships for San Luis Facility ... .............................23
Table 2
PMF Peak Flow Comparisons: Original Design and Current Analysis .................28
Table 3
PFMA Screening Categories ..................................................... .............................37
Table 4
Descriptive Probabilities ........................................................... .............................38
Table 5
Consequences Categories .......................................................... .............................39
Table 6
PFM -1: Overtopping of Drop Structure during Flood Event ... .............................44
Table 7
PFM -2: Internal Erosion or Piping of Embankment Materials .............................48
Table 8
Summary of Risk Estimates and Justification for Action ......... .............................51
LIST OF FIGURES
Figure1 General Site Map ................................................................................ ..............................1
Figure2 Tailing Impoundment ......................................................................... ..............................5
Figure 3 San Luis Tailing Dam Typical Cross Section .................................... ..............................7
Figure 4 Results of Upstream Stability Analyses ............................................. ..............................9
Figure 5 Results of Downstream Stability Analyses ....................................... .............................10
Figure 6 Site Visit 2, Right Abutment Groin Erosion Gulley before Repairs, Looking
Upstreamfrom Near Toe ...................................................................... .............................12
Figure 7 Initial Site Inspection, Right Abutment Groin Erosion Gulley After Repairs,
Looking Downstream from Near Crest ................................................. .............................13
San Luis Project Miller Geotechnical Consultants
Tailing Dam Data Report iv February 2014