AirX Utility Surveyors specializes in Subsurface Utility Engineering
Utility Engineering is the study of existing underground utilities in each area and is generally used in the development of a design for a new construction project. This study can provide vital information for design, but it is also essential for safety during excavation. To have first-hand knowledge of what exists below the surface, what type of utilities can be expected, the size of utility or conduit, how deep it is, and where it goes? Having this information from the start will assure a thorough and competent design that will assist construction throughout the project. Delays and last-minute design changes will be drastically reduced or possibly even eliminated, making a much smoother, more efficient process for your project altogether.
There are four different quality levels of Subsurface Utility Engineering, and careful consideration should be given to the needs of your project. The ASCE published Standard 38-02 in 2003, entitled “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data” identifies and discusses these levels. And the American Society of Civil Engineers is based on the degree of risk when using the information in a project. These four levels are as follows:
- QL-D DATA – the most basic level of utility data. The information at this level comes entirely from existing records or personal recollections, both of which are generally considered unreliable. QL-D data is primarily used to assess the overall concentration of underground utilities, as its use in identifying the location of specific utilities is limited. The most common application of QL-D data is general project planning and route selection.
- QL-C DATA – probably the most common quality level of utility data. The primary sources for this information include surveys of visible facilities such as manholes and valve boxes, which are typically correlated with QL-D information. This process often identifies utilities that have been incorrectly plotted or are completely missing from the QL-D sources. The most common uses of QL-C data include projects in rural areas, where the repair and relocation of utilities is relatively inexpensive.
- QL-B DATA – comes from surface geophysical methods that precisely locate the position of utilities within a particular area. The primary purpose of this process, also known as “designating,” is to correct inaccurate utility records, including missing references and unrecorded facilities. The proper selection and use of geophysical techniques is critical for the classification of QL-B data since these are key factors in determining the accuracy of this type of data. QL-B data is often used to accomplish preliminary goals in engineering projects. For example, it can facilitate decisions regarding the location of proposed design features such as drainage systems, foundations, and footers to avoid conflicts with existing features. Therefore, the value of QL-B data lies in its ability to eliminate utility relocations, which can often result in substantial savings by making slight adjustments to a design.
- QL-A DATA – provides the highest level of accuracy presently available for subsurface utilities. The process of collecting this data is known as “locating” and involves the full use of SUE services to expose utilities through nondestructive means. QL-A data provides highly accurate information on the characteristics of underground features, including their composition, condition, size, and type. The most common use of data with this quality level is the precise mapping of utilities, typically for projects in congested urban areas.
AirX provides Utility Locating, Vacuum Excavation (Potholing), and CCTV of Sewers, Sewer Laterals, and Storm Drains to support this data collection. We also provide numerous support services such as Plan Drafting, Permit Processing, Traffic Control Technicians and Equipment on Site, Asphalt Hot Patching, Concrete Repairs, Mapping, and Project Management. These services can be tailored to suit your specific needs.