A publication for those interested in topics relating to above-ground and subsurface utility locating, and Geographic Information System (GIS) and Glo

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A publication for those interested in topics relating to above-ground and subsurface utility locating, and Geographic Information System (GIS) and Global Positioning System (GPS) mapping. Join us on the 3rd Wednesday of every month to explore how cutting edge technology and innovation, combined with a desire to educate and protect the public, will serve you well as a professional in the land use industry.


In this issue: April 2013 Issue 2

Integrating Technologies: How It Can Save You On Your Next Project
Resources: Sites and Documents to Have On Hand
In the News: Articles About Utility Locating and Mapping
Contact Us


Integrating Technologies


Alex uses the Topcon Hyper II GPS unit to record the coordinates of the electric power line going to the street lamp. The utility was located using a Tx-10 transmitter.

Technology evolves when the foreseeable need arises.

With infrastructure constantly expanding, the network of underground utility lines below our feet continues to become more complex and congested. Cables and pipes layer upon each other at various depths and directions, serving different purposes, each one with a potential to pose great risk should it be damaged during excavation. For safety and future planning, it is vital to understand the location of these facilities. This involves different methods of locating, and reinforces the benefit of storing data for long term use.

We will discuss methods for locating in greater detail next month, but in general, metallic utilities can be located by using a transmitter to apply an electromagnetic field that wraps around the conducting metal of the cable itself. The receiver, or wand, from the paired equipment can be tuned to the oscillation frequency of the electromagnetic field and can trace the position of the field as it travels down the path of the conducting metal of the utility.

For subsurface utilities not composed of metallic material, and thus not capable of carrying an electromagnetic field, such as those made out of clay, concrete, or plastic, equipment such as the Ground Penetrating Radar (GPR) is used. The GPR uses radar pulses in the microwave band of the radio spectrum to create subsurface images, similar to an MRI you would get at the hospital.

The congestion of underground facilities, type and condition of lines, and the conditions of the ground will influence method of location. This means that not only is it necessary to utilize current locating equipment, but since ground conditions will change in the future, the locations of these lines need to be recorded, and better yet, they should be mapped.

Below is an excerpt from the Common Ground Alliance's 2013 Best Practices document, on "Emerging Technologies":

Although the following technologies are now used in other applications, their use is not widespread in the damage prevention field:

Geographic Information System (GIS)
Global Positioning System (GPS)
Orthographic and satellite imagery

GIS allows the integration of digital maps with other databases to view the relationship of physical features; conducts relational queries; and obtains additional information on a particular feature. The GIS infrastructure or base will support all of the advanced technologies of GPS, orthographic. and satellite imagery.

Combining orthographic and satellite imagery with an overlay of a line map, street names, addresses, and GPS coordinates of utility lines will allow one call centers, excavators, locators, facility owners/operators, and project owners to view the accurate and relative location of utility lines.

Advanced use of these technologies in combination with advances to locating technologies is expected to reduce damage to underground facilities.

A link to this document can be found below.


Did you know?

April is National Safe Digging Month!

Call 811 has created all kinds of promotional tool kits to raise awareness about safety issues associated with digging. They are free to download and use by Common Ground Alliance stakeholders.

Common Ground Alliance: 2013 Best Practices Version 10.0

The Common Ground Alliance is one of the major resources for standards and best practices within the industry. They were established to help prevent damage to underground infrastructure and increase safety by fostering a sense of shared responsibility for the protection of underground facilities, to support research development, conduct public awareness and education programs, identify and disseminate stakeholder best practices, and serve as a clearinghouse for damage data collection analysis and dissemination.
You can access the most recent publication on best practices here.

Accident Prevention Begins Before Excavation

By Jeff Griffin, Senior Editor of Underground Construction, Jan. 2012, Vol. 68, No.1
This article gives a brief description of the "One Call" utility location system. It's important to note how many times they highlight the need for accurate record keeping when locating utilities for excavation.

"This information should be transferred to an on-site computer, tablet or office computer to preserve the information and then stored by project number or in project files. These records can be invaluable later if a dispute arises over responsibility for improperly located and marked facilities." Read more...

Just imagine the simplicity of having survey-grade GPS on-site during locates. The utilities could be marked, located with GPS, and then mapped and stored in a GIS layer. Better yet, imagine the simplicity of hiring a company that could do all three! You've just saved time and money, while increasing safety, and you now have long-term access to data for future projects.

2011 DIRT Data Analysis & Recommendations

CGA National Gas Distribution Facilities Report, released March 2013.
Below is a diagram from the latest Damage Information Reporting Tool (DIRT) report. Analysis of the main causes of damages reported indicate that locating and excavation practices are highly insufficient. This is representative for natural gas lines, but it surely holds true for all utilities. In terms of locating, the issue was mainly that markings were inaccurate, incomplete, or not visible.
View the report here.


Thank You

We would like to thank you for your interest in Above And Below. We welcome your feedback as we launch this new publication, and hope that you find it both interesting and informative.


Want to learn more about AAB Utility Locating and Nadeau Land Surveys?
Visit our website at www.aabutilitylocating.com

Have a specific question?
Email Jim Nadeau, at jim@aabutilitylocating.com.

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