What is Subsurface Utility Engineering or SUE?

SUE is an acronym for Subsurface Utility Engineering, a branch of engineering that involves utility design and relocation services. A crucial component for any SUE project involves designating and locating existing underground utilities.

Subsurface utility locations & designations provide utility conflict avoidance by mapping existing underground utility facilities. CHW utilizes surface geophysical technologies, vacuum excavation, surveying, and data management systems to provide Quality “A” through “D” designation.

Our goal is to apply our surface and subsurface mapping skills to improve our clients’ bottom lines and reduce their risks.

CHW’s surveying and mapping team incorporate existing and emerging technology to identify, characterize, and map underground utility facilities throughout the project development process. This aspect of the design phase of building and construction helps manage the risks associated with unexpected encounters with underground utilities. Engineers can design the most efficient systems and reduce overall project costs by utilizing the most accurate utility mapping and information on the existing utilities using the Subsurface Utility Engineering support services.

Why SUE?

SUE is a process, not a technology. SUE is defined as a branch of engineering practice that involves managing certain risks associated with:

+ utility mapping at appropriate quality levels,
+ utility coordination,
+ utility relocation design and coordination,
+ utility condition assessment,
+ communication of utility data to concerned parties, conflict avoidance,
+ utility relocation cost estimates,
+ implementation of utility accommodation policies, and utility design.

These activities, combined with traditional records research and site surveys, and utilizing new technologies such as surface geophysical methods and non-destructive vacuum excavation, provide “quality levels” of information.

Levels of Subsurface Utility Engineering

CHW uses several different tools and methods to perform these SUE utilities mapping services, depending on the different quality levels of data necessary for the project. According to the ASCE Standard 38-02, used across the Architecture, Engineering, and Construction (A/E/C) industry, there are four different subsurface utility engineering levels of data quality (QLs):

Level D (QL-D) – Record Research/Data Collection: This level of data is derived from records research or oral history. It gives an idea of how congested the area may be but does not provide specific and accurate detail for utility locations. Any existing conditions plan with a utility level documented on record is automatically considered Level D data by the subsurface utility engineering standards outlined in the ASCE 38 02 standard.

Level C (QL-C) – Visible Surface Feature Utility Survey: Level C data maps out utility surface features by surveying the area and plotting what’s visible above ground. Using these features along with utility records, you can then map underground utilities.

Level B (QL-B) – Utility Designation: This data level is collected using geophysical equipment operated from the surface to designate the locations of underground utilities. Utilities are marked out and recorded on a map with plan documents.

Level A (QL-A) – Underground Utility Locating (Test Hole): This is the highest confidence level of utility locating. Each test hole allows for visual confirmation that guarantees the utility’s horizontal and vertical mapping location. SUE Level A is accomplished using non-destructive vacuum excavation to expose, measure, and map utilities safely.

 

SUE Technologies: Multiple Tools and Approaches

CHW has an extensive history of using multiple tools to retrieve the quality level of utility data necessary for your subsurface engineering projects:

Electromagnetic induction tools help to locate conductive underground utilities

State of the art ground penetrating radar (GPR) equipment is used to locate conductive and non-conductive underground utilities.

After the existing utilities are designated, the next step is to verify their locations at all points of interest and where the new proposed utility route crosses the existing utilities. Hydro vacuum excavation trucks help to expose utilities for collecting accurate depth information critical for designated utility crossings. Vacuum excavation reduces the risk of damaging underground utilities and is especially useful in high utility congestion or confined spaces.

 

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Recent CHW SUE Services Projects

		COLLEGE OF CENTRAL FLORIDA The CHW Surveying + Mapping team worked with Moses Engineering to support the expansion and improvements for the Chilled Water Plants on the College of Central Florida Campus in Ocala, Florida. CHW’s Subsurface Utility Engineering (SUE) crew worked with Moses Engineering to create survey limits based on the proposed corridor for the upgraded Chilled Water line. Our final survey provided quality level “B” locations of existing utilities to ensure clearance to route the larger Chilled Water Pipes.

		UNIVERSITY OF FLORIDA The CHW Surveying + Mapping team partnered with the University of Florida and RMF Engineering to support the Chilled Water expansion and improvements throughout the UF campus in Gainesville, Florida. CHW’s Quality Level “D” and “B” utility maps assisted in designing these Chilled Water upgrades. To ensure no existing utilities crossed at the proposed locations, we Verified the Vertical and Horizontal positions (VVH), Quality Level “A,” from the west end of the UF Reitz Union, down the entire length of Inner Road, across SW 13th Street, to Norman Hall. CHW’s Subsurface Utility Engineering (SUE) crew determined if any existing utilities would conflict with proposed traffic signal mast arms through non-destructive exploratory digs using vacuum excavation at two corners of SW 13th Street and Inner Road.

 

Benefits of SUE