|SUE - An Engineering Practice
Subsurface Utility Engineering is an engineering practice
What exactly is the practice of SUE? Take into consideration that SUE today is an engineering practice. It is no longer paint marks on the ground or vacuum excavation. These technologies are not even mentioned in the ASCE definition. They may be part of SUE, but then again, they may not be.
The practice of SUE doesn't follow any set pattern. Rather, it is tailored to individual projects. It essentially involves systematically identifying the quality of utility information needed to design a project, and acquiring and managing that level of information.
The practice of SUE works best when it is coordinated and provided by an experienced and knowledgeable consulting engineer. Such an engineer would typically coordinate and perform the following tasks:
- Identify utility owners that have facilities on, or may be affected by, the project. Contact these utility owners (...face-to-face meetings are preferable) and provide them with information about the proposed project. Schedule periodic follow-up meetings.
- When the highway plans are about 30% completed, or possibly even sooner in the planning phase, provide the plans to utility owners along with a request that they review the plans and provide pertinent as-built or other existing utility information. Obtain existing utility information from other sources. Review all information that can be obtained and plot it on a utility composite drawing or equivalent. This is Quality Level D (QL-D) information.
- Make field observations to identify visible above-ground utility features. Survey and plot resulting information. This is Quality Level C (QL-C) information. It is correlated with the records information (QL-D). When records and features information do not agree, resolve discrepancies.
- Use appropriate surface geophysical methods (i.e., pipe and cable locators, terrain conductivity methods, resistivity measurements, metal detectors, Ground Penetrating Radar, etc.) to designate existing subsurface utilities or to trace a particular utility system. This provides two-dimensional horizontal information. Place paint marks on the ground. Place identification flags or stakes on the paint marks or coding on the pavement at 50-foot intervals and survey to project control. Depict resulting information via computer-aided design and drafting (CADD) or manual plotting onto the client’s plan sheets, Geographic Information System (GIS) databases, or other appropriate documents. This is Quality Level B (QL-B) information. If requested by the project owner, also perform surveying and depict information about aerial utilities.
- Resolve differences between QL-B, QL-C, and QL-D information. This may involve additional surface geophysical searches and/or actual exposure of some subsurface utilities. This may require re-depicting utilities that have previously been depicted in order to present the more accurate information.
- Develop a conflict matrix showing all possible highway/utility conflicts. This involves comparing depicted utility information with proposed plans (highway, bridge, drainage, maintenance of traffic, and other). The resulting matrix contains columns to record the physical location of each conflict, the name of the utility involved, the nature of the conflict, the action needed. Upon analyzing the information recorded on the matrix, it will be obvious that some conflicts can be readily resolved, some conflicts are questionable and additional information is needed, and some conflicts cannot be resolved.
- Convene and facilitate a meeting with utility companies to discuss potential conflicts and other aspects of the project. Discuss possible strategies to avoid conflicts and identify locations where additional three-dimensional information is needed.
- Expose selected subsurface utilities to obtain three-dimensional information. Use minimally intrusive excavation methods, such as vacuum excavation. Depict resulting information. This is Quality Level A (QL-A) information.
- Resolve differences between QL-A information and the previously obtained QL-B, QL-C, and QL-D information. Depict new and corrected information. Go back to the conflict matrix with the new QL-A information to determine the status of conflicts requiring additional information. Meet with utility companies to discuss these conflicts and possible strategies to avoid utility relocations.
|CI/ASCE 38-02 Guideline
for the Collection and Depiction of Existing Subsurface Utility Data CI/ASCE 38-02
The Federal Highway Administration (FHWA) and many other agencies recognize Cardno TBE as being a leader in Subsurface Utility Engineering (SUE). For years, Cardno TBE has been setting targets and standards in the practice of SUE. Several Cardno TBE associates served in the development of the American Society of Civil Engineers' (ASCE) Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data CI/ASCE 38-02, and Cardno TBE currently has a member on the Standards Update Committee. Cardno TBE regularly provides SUE training seminars throughout the country. While the ASCE Guideline is not a “SUE standard” per se, it does provide a standard approach to key elements of SUE.
In 2003, the American Society of Civil Engineers (ASCE) published and distributed a document entitled “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data”. This standard formally defined SUE and set forth standard guidance for collecting and depicting SUE information. This essentially elevated SUE to a new level.
The ASCE standard presents a system of classifying the quality of existing subsurface utility data. Such a classification allows project owners, engineers, and constructors to develop strategies to reduce or allocate risks due to existing subsurface utilities in a defined manner. As a handout or as part of a specification, it assists engineers, owners, and contractors in understanding utility quality level classifications and their allocations of risk. The standard closely follows concepts in place in the SUE profession. Therefore, many states are already in “compliance” with this standard through their use of SUE, or through their inclusion of SUE specifications in their engineering contracts.
The ASCE standard makes it very clear that SUE is a process, not a technology,
and it defines SUE as follows:
Subsurface Utility Engineering (SUE): 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, utility relocation cost estimates, implementation of utility accommodation policies, and utility design.
The basic elements that comprise the SUE process are contained in this definition.
To order a copy of the ASCE Guideline, please go to the ASCE Bookstore:
- Deliver depicted information to the project owner. The basic deliverables for utility information are generally a CADD file, a GIS file, or a plan sheet that has utility information in plan view for Quality Levels A, B, C, and D and in profile view for Quality Level A.
- Work with the project owner’s designers to be sure they understand the information provided and to suggest possible ways to avoid conflicts.
- Where conflicts cannot be avoided and utilities will have to be relocated:
- Determine prior rights.
- Obtain relocation cost estimates and plans from utility companies.
- Prepare utility relocation agreements.
- Provide utility relocation design.
- Acquire necessary right-of-way.
- Collect and store pipe location and condition information in a database for asset management.
- Work with utility companies, one-call centers, and contractors during construction as needed.
- Continue to represent the utility owner in all utility-related activities as the project progresses.
In regard to the above tasks, several important things need to be kept in mind:
- These tasks may be provided by the project owner, but are more commonly performed by a consulting engineer working closely with the project owner. They are most effectively utilized when coordinated by a professional utility coordinator employed by the engineer. The utility coordinator is responsible for working with the owner and the affected utilities to determine the need for each task and to ensure that selected tasks are performed properly and expeditiously.
- These tasks may be used in a different sequence than that prescribed above (i.e., it may sometimes be more practical to perform (a) QL-C tasks before and/or in conjunction with QL-D tasks, and/or (b) QL-B tasks before and/or in conjunction with QL-C or QL-D tasks).
- Some of these tasks should be used on every project, but it may not be necessary to use all of them (e.i., QL-D and QL-C information may be all the information deemed necessary for a particular project). If not willing to accept a particular risk, project owners may opt to obtain additional information. Determinations may be made every step of the way until acceptable risk levels are achieved.
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|Cardno TBE offers the full gamut of SUE services
Overview of Subsurface Utility Engineering services provided by Cardno TBE
Click the above link to see a brief description of the list items below, learn about the evolution of SUE and Cardno TBE's involvement with the ASCE standards. If you would like to learn about a specific service click the respective link below:
. 3D Underground Imaging
. Utility Coordination
. Utility Design
. Ground Penetrating Radar
. Surveying & Mapping
. Global Positioning Systems
. Geographic Information Systems
. Sample "Scope of Work"