Kasey Hayes , subsurface utility engineering leader in Ayres ’ Fort Collins , Colorado , location , more succinctly summed up SUE ’ s importance : “ SUE helps mitigate utility conflicts , damages and exposures that lead to down time , extra costs , change in design during construction , and most importantly , injuries and even death .”
Providers of SUE services create deliverables containing a depiction of utilities that meet one of four quality levels , depending on the needs of each project and client . The ASCE has defined the quality levels based on the level of certainty of a subsurface utility ’ s location . A quality level is assigned based on the extent of utilities investigation , with the lowest level , D , relying on a search of utility owners ’ existing records and the highest level , A , involving a physical locating process using test-holing and mapping of a precise profile of utility locations .
Increased safety , reduced costs : SUE quality levels defined
Subsurface utility engineering provides information and reliability defined by four quality levels :
Quality Level D : The most basic level of information for utility locations . Comes solely from existing utility records or verbal recollections ; both typically are unreliable sources . Useful primarily for project planning and project site selection .
Quality Level C : Commonly used level of information . Involves surveying visible utility facilities ( e . g ., manholes , valve boxes , etc .) and correlating this information with existing utility records . Often this information shows that many underground utilities have been omitted or erroneously plotted . Useful primarily for rural projects where utilities are not prevalent or are not too expensive to repair or relocate .
SUE blends utility designating and locating , surveying and mapping , and data gathering and management to identify and catalog utilities on a project site . Before construction begins , SUE professionals provide project designers a precise depiction of identified subsurface utility lines and related structures in the project area .
How , exactly , is that precise mapping of subsurface utilities achieved ? First , SUE professionals use any pre-existing data and on-site markings from utility owners as a starting point for determining where underground utilities are located . They then employ technologies including electromagnetic tracing and groundpenetrating radar to better hone in on the horizontal locations of underground lines and any other subsurface structures .
Quality Level B : Involves the application of surface geophysical methods such as electromagnetic locating or ground penetrating radar to “ designate ” the existence and horizontal position of all utilities within the project limits . Information obtained is surveyed to project control . Addresses problems caused by inaccurate utility records , abandoned or unrecorded facilities , and lost references . Decisions regarding location of storm drainage systems , footers , foundations , and other design features can be made to avoid conflicts with existing utilities . Slight adjustments in design can produce substantial cost savings by eliminating utility relocations .
Quality Level A : Known as “ locating ,” this level provides the highest accuracy and involves full use of SUE services . Provides information for the precise plan and profile mapping of underground utilities through the nondestructive exposure of underground utilities . Also provides the type , size , condition , material , and other characteristics of underground features .
Source : Federal Highway Administration
Finally , SUE providers , in coordination with project engineers , will conduct test-holing to
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