Capital Utility Locators - Your Trusted Utility Contractor

  Subsurface Utility Engineering (SUE) is a practice that uses advanced technologies like surface geophysics (e.g., GPRS, cable tracers), surveying, and minimally intrusive excavation to map and manage utility data, reducing project risks. The purpose of SUE is to enhance decision-making by providing reliable utility location data during project design and construction, minimizing conflicts with buried infrastructure.

The ASCE 38-22 standard, published by the American Society of Civil Engineers, provides a framework for collecting and depicting existing subsurface utility data to manage risks in infrastructure projects. It addresses the challenges of inaccurate or incomplete utility information, which can lead to costly conflicts during construction.

The standard defines four quality levels (QL) for utility data, each with increasing accuracy and reliability:

1. Quality Level D (QL-D): Basic data from existing records or oral histories.      Involves researching utility owner records, such as as-builts or      distribution maps, to identify potential utilities.
2. Quality Level C (QL-C): Builds on QL-D by surveying visible above-ground      utility features (e.g., manholes, valves) and correlating them with      records to estimate subsurface utility locations.
3. Quality Level B (QL-B): Uses surface geophysical methods to determine the      approximate horizontal position of utilities. Data is surveyed and mapped,      ensuring reproducibility with geophysical tools.
4. Quality Level A (QL-A): Provides precise horizontal and vertical utility      locations through minimally intrusive excavation (e.g., test holes).      Achieves high accuracy (typically 15 mm vertically) and includes detailed      attributes like material, size, and condition.

• Cost Savings: Studies (e.g., Purdue University, 1999) show that using QL-B and QL-A data can save 1.9% of project costs, with a return of $4.62 per $1 spent on SUE. Savings come from reduced utility relocations, construction delays, and overruns.
• Costs: Implementing QL-B and QL-A typically costs 0.5–1% of a project’s design and construction budget, with higher costs for urban projects due to complex utility networks.