QL-A Vacuum Excavation:
Benefits: The benefit of conducting test holes on your project is that they determine the “actual” horizontal and vertical positioning of the existing utilities or structures at the point of investigation. The data can be used to avoid any conflict that may be potentially identified during the design process. It allows the Project Engineer/Designer to reduce his/her risk as it pertains to the existing utilities, as well as preserve the integrity of the design. Quality Level ‘A’ services are best used during the design process after the Engineer/Designer has processed and utilized the Quality Level ‘B’ data, and has had the opportunity to identify potential utility conflicts. However, these services can be used at any point during the design or construction process.
For final project design, and early construction phases of a project, SUE Solutions excavates test holes to determine the exact horizontal and vertical location of existing utilities. As part of this process, SUE Solutions contacts Utility Owners prior to commencement inquiring of their desire to be on-site while excavating. The method for potholing can generally be described as follows: At the identified conflict locations, a 10″x1 0″ or 12″x12″ cut in the asphalt or native soil is made, and using an air lance or water gun, the soil is agitated and vacuumed into a spoils tank located on the truck or trailer. Once the utility has been exposed, a measurement is taken from the existing ground surface to the top of the utility, via measuring rod or GPS survey (where possible), along with other critical data being collected pertaining to the exposed utility, and then is recorded on field data sheets. Once completed, the native soil is placed back into the hole (if air is used, otherwise, import fill will be placed and the spoils discarded), the hole is then compacted, and an asphalt cold patch will be placed when applicable. A PK nail or HUB is placed above the utility in the asphalt or unimproved area, where it will then be surveyed.
Accuracy: Much like the standard SUE Solutions places on horizontal positioning (Quality Level ‘B’ – designating), the same is placed on its subsurface test hole investigations. The accuracy level of the supplied vertical data can be defined as ± % inches in X, V, and Z directions. The purpose of this is to control and minimize the risk of potential utility conflicts, relocations, and redesign costs, should the service NOT be used at any point within the process.
Deliverables: As a deliverable for this service, SUE Solutions will provide a report of its findings in the field (general locations and limitations), project photographs (of QL-A test holes), Test Hole Data Sheets (providing depth, sizing, material type, utility owner information, etc), survey data (should that be part of the initial Scope), and digital data/mapping should it be requested.