You may not be a Civil/Structural engineer, based on your comments regarding facility (tailing pond/dam) design.  Previous ND information has proposed an earth-fill dam in our high seismic zone.  Earthen dams easily fail for many reasons; lack of suitable foundation, groundwater intrusion, lack of suitable engineered soil material as well as seismic forced response of the dam structure itself.  Many earthen dams have failed in road-accessible locations that had the benefit of suitable engineered fill material, state-of-art construction and geotechnical exploration  equipment as well as significant analysis and design tools for the seismic response analysis and design.  The best analytic tools are only as good as the soils data available and are statistically based for the design earthquake.  Seismic response of soil is poorly defined and the design earthquake is a best-guess estimate at best.  There are many variables that will be unknown due to the remoteness of the location.