Subsurface Utility Engineering (SUE) is an effective means of verifying and mapping the location of existing underground utilities and combines civil engineering, surveying, and geophysics. Collecting data from all available sources enables our licensed professionals to provide clients with the most complete information available. This includes employing a combination of geophysical methods, civil engineering, survey mapping, ground penetrating radar (GPR) and other nondestructive technologies. SUE is a critical part of the design process for new and existing infrastructure projects that saves clients time and cost by helping to eliminate unexpected utility conflicts and unnecessary relocations while enhancing safety during construction.
Our professionals operate in accordance with national ASCE-38-02 Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data addressing all four quality levels (A, B, C & D) and combinations thereof.
Quality Level D (Records Research / Data Collection):
Is simply the process of gathering record data (which is not necessarily so simple). This data could be digital records, paper records, internet search, site inspection or just talking to people who are familiar with the site. The available data could be limited and not produce a complete picture of what is onsite. And if the source of some data is unknown or questionable, the completeness and accuracy of the investigation could be compromised. In any event, once the data is collected, it is compiled into a drawing that states the quality level.
Quality Level C (Above ground survey):
Involves the process of surveying the visible utility features, or if they have already been surveyed, checking the surveyed locations for their accuracy. This data is compiled with the Quality Level D data and both levels are labeled accordingly. Quality Level C data could, and often will, conflict with the Quality Level D data and raise questions as to the locations of some underground utility lines.
Quality Level B (Utility Designation):
Involves designating the underground utilities, for example, by markings provided through an 811 call or by contacting an individual utility company. This data is added to the data collected from Quality Levels D and C. The designated utilities are then surveyed and added to the drawing which can then be identified as representing the results of a Quality Level B investigation.
Quality Level A (Test Hole / Pot Holing):
Involves physically locating the actual utility – often by ‘potholing.’ Once the utility is potholed it is located horizontally and vertically by survey measurements. This location is typically to the top of pipe, which should be noted on the drawing.