OCR Text |
Show alinement or location to obtain the most suitable and stable site. Detailed surface and subsurface investigations are performed only after the two initial stages are completed to guarantee a thorough knowledge of inplace conditions. In this sequence of stage investigations numerous drill cores are obtained and studied. Some of these drill holes may project to depths more than 1000 feet depending on the foundation requirements. Often during the design stage instrumentation is included to monitor the performance of the structures. Investigations of earth materials for embankment are pursued in great detail by field sampling and laboratory testing. Petrographic and chemical tests are normally performed on foundation rock and aggregate material. An extremely refined measure of safe construction has evolved from many years of use of this system of investigation. These reports are referenced in the final environmental statement and are available for public inspection. It is necessary that anyone interpreting Bureau of Reclamation investigative data be knowledgeable in its meaning and significance, and be able to relate these data in total to the particular feature. For example the term slide, slump, or land slide does not necessarily signify danger or hazardous conditions. There are numerous interrelated structural elements, shape factors, and hydrologic relationships that determines the failure and hazard potential of a slide mass. It is the assigned responsibility of the geologist to alert intended offices of any potential unstable conditions or geologic hazards relative to the plan, but this does not mean that these hazards cannot be safely dealt with. Earthquake potential is another hazard that is considered. Potential damage by earthquakes must be extended to all existing and potential structures including buildings, highways, bridges, and utility lines- not just those related to water projects. All features are designed with this hazard in mind after thorough foundation investigations have been completed. Based on past experience, Bureau of Reclamation dams, designed and constructed to withstand earthquakes, perform their intended function with greater safety than many of the above- mentioned structures. Discussion of geological aspects of the Unit area and specific features appear in paragraphs BU and B5 and in several portions of Section C. Issue 3* The Draft Environmental Statement failed to adequately < l • mi » i i i i i ii i i i i a » in i i » • i ir i i » » i » ii « • n 0 i i II m II II i) I | i I I r . explain and evaluate the Indian Deferral Agreement as it relates to the Bonneville Unit and the Central Utah Project. ( a) The Bonneville Unit borrows water from the Indians which is to be replaced at a later date by other 645 |