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<br />requ I red by certa I n Co I orado Statutes. Senate B II I 35
<br />(C.R.S. 1973, 30-28-101, 110(3)-(5), 133-137) and House Bills
<br />1041 (C.R.S. 1973, 24-65.1-101, et seq.) and 1529 (C.R.S.
<br />1973, 34-1-301, et seq.) require that geologic hazards and
<br />minerai resources be considered prior to development
<br />activities. Geologic hazard is defined In H8 1041 as "a
<br />geologic phenomenon which is so adverse to past, current, or
<br />foreseeable construction or land use as to constitute a
<br />significant hazard to public health and safety or to
<br />property.11 A mineral resource area Is defined in this same
<br />
<br />bi II as Itan area in which minerals are located In In
<br />sufficient concentration in veins, deposits, bodies, beds,
<br />seams, fields, pools, or otherwise, as to be capable of
<br />economic recovery...11 Local governments are empowered to
<br />regu I ate davs! opment in these hazard or resource areas by
<br />Senate B I II 35, House Bill 1041, and by House B i I I 1034
<br />(C.R.S. 1973, 29-20-101, et seq.). Regardless of the legal
<br />requirements It is In the best interest of the designer,
<br />developer and bui Ider and financial institutions to obtain a
<br />report on the geologic conditions before a project Is begun
<br />50 that the results of a geologic Investigation can be
<br />Incorporated Into the project planning. Geologic Information
<br />can be used to save development and construction costs or,
<br />perhaps, liabilities and legal costs by acquainting the
<br />developer or contractor with adverse geologic conditions and
<br />their Impact on the proposed project. Ultimately, the use of
<br />Information contained in the report also could save local and
<br />state governments, and the taxpayers from excessive expense
<br />resulting from failure to recognize and cope with natural
<br />hazards. Private property owners benefit by preventing
<br />foreseeable devaluation of their holdings.
<br />
<br />A II eng I neer i ng geo logy reports shou I d be prepared and signed
<br />by a Professional Geologist as defined by Colorado law, House
<br />Bill 1574 (C.R.S. 1973, 34-1-20, et seq.). To prepare a
<br />camp I ete and accurate report, the geo I og i st must have spec I a I
<br />education and experience in the field of engineering and
<br />environmental geology. The geologist who does not have this
<br />general training and experience should refrain from doing
<br />engineering geology studies or should work under supervision
<br />of a geologist who is experienced in this field. The report
<br />should be prepared In accordance with the highest prevailing
<br />standards of the profession real izing that omissions of
<br />significant data are as serious an error as giving
<br />misinformation.
<br />
<br />General Content of Engineering Geology Reports
<br />
<br />Engineering geology reports generally contain three distinct
<br />and essential elements: 1) data, 2) Interpretation of the
<br />data, and 3) conclusions and recommendations.
<br />
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<br />
<br />Data: Keport data are facts used as the bas i s for
<br />interpretations, discussions, and conclusions. These facts
<br />are the cornerstone of the report and are obta I oed from
<br />publ ished documents, surface and subsurface investigations,
<br />and field and laboratory tests. Surface studies generally
<br />incl ude topographic surveys, geologic mapping, and the review
<br />of aerial photographs or other remote-sensing imagery.
<br />Subsurface investigations can include geophysical surveys,
<br />dri 11 holes, test pits, and trenches. Field and laboratory
<br />tests may cover the analysis of various factors involving
<br />soils engineering, sewage leach fields, water quality, or
<br />m I nera I resources.
<br />
<br />Geoloalc conditions which should be described In the report
<br />Include bedrock units, surficial deposits, geomorphic
<br />features, structura I features, surface dra I nage, ground-water
<br />conditions, and minerai resources. Description of 'the
<br />conditions wi 11 differ markedly in their degree of detail and
<br />specificity depending on the particular method or technique
<br />used In gathering data. The limitations of the method or
<br />techn i ques used and the qua II ty of the data shou I d be
<br />discussed. Where Interpretations are added to the recording
<br />of direct observations, the basis for Interpretations must be
<br />clearly stated.
<br />
<br />Int~rpretatlon: After the geologic data has been presented,
<br />it IS analyzed with regard to geologic hazards and geologic
<br />constraints, mineral resources, and water conditions.
<br />Geologic hazards are conditions that eventually will affect
<br />the safety of persons and property by i nstab I II ty of the
<br />ground surface or inundation of the surface by debris, mud,
<br />snow, or water. Instability or inundation may be caused by
<br />either natural or man-induced processes such as landslides
<br />debris flows, mudflows, flooding, faulting, avalanches;
<br />rockfall, and subsidence over underground mines. Paramount
<br />In the analysis of geologic hazards and constraints Is the
<br />recognition and evaluation of natural processes as well as an
<br />estimation of the recurrence interval for a specific size and
<br />kind of event. Colorado Geological Survey Special
<br />Publication 6 (Kogers and others, 1974) offers detailed
<br />descriptions of these processes. It defines the processes,
<br />gives the criteria for recognition,. and anticipating the
<br />consequences of improper ut ill zat I on. I t a I so suggests
<br />mitigation procedures.
<br />
<br />Geologic constraints are conditions that probably wi I I not
<br />result in the loss of life but could cause significant added
<br />construction expense or property damage. These constraints
<br />may be control led by by proper design and construction. The
<br />lack of proper design or construction could initiate or
<br />aggravate specific geologic processes and escalate
<br />construction and maintenance costs. These costs could
<br />determine project feasibility, especially If they are not
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