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In a previous issue of Utility, Bruce Potter discussed how the AS5488-2013 Classification of Subsurface Utility Information eliminates inconsistencies in subsurface utility information for a variety of purposes  throughout the lifecycle of the asset. Here, he looks at the role of utility locators and how important they are in the identification and protection of subsurface utilities.

The utility locating industry in Australia plays a crucial role in the protection of essential services through non-destructive methods and equipment, and has embraced AS5488-2013 Classification of Subsurface Utility Information (SUI) as a means to identify and convey invaluable utility information.

Realistically some utility owners simply don’t know the actual location of their own utilities, or are reluctant to provide more accurate data to construction operators seeking reliable utility information. Utility locators are the link on the ground that binds utility owners/operators to the construction community.

Experienced utility locators have a wealth of knowledge of all aspects of subsurface utilities – from reading and understand utility owner plans, to design principles and construction installation methods. Trained to operate a variety of locating equipment, including radio detection and ground penetrating radar to detect subsurface utilities, they understand geophysics and how subsurface utilities react to certain types of locating equipment.

A focus on training

The construction industry in Australia is bound by legislations and regulations. The Workplace Health and Safety Act 2011, section 274 (Approved Codes of Practice), outlines the Code of Practice for construction work and excavation work and applies to anyone who has a duty of care in the circumstances described in the code. An approved code of practice is a practical guide to achieving the standards of health, safety and welfare required under the WHS Act and the Work Health and Safety Regulations (the WHS Regulations).

The National Utility Locators Contractors Association (NULCA) is the industry body that oversees training for the locators and is a voice for all working in the utility locating industry across the country, while Dial Before You Dig (DBYD) is the industry body representing utility owners and operators that are DBYD members.

To facilitate public and industry confidence in the utility locating community, the Certified Locator program was recently introduced in Australia. This has been overwhelmingly supported by the operators within the utility locating industry as a move to have the locating industry recognised as at trade profession, and while it is still somewhat new, the subsurface utility owners and the greater construction industry have also embraced this certification.

NULCA and DBYD have become co-advocates to ensure their members are involved and all training undertaken will meet Australian Skills Quality Authority (ASQA) standards and approval. This certifies that a utility locator possesses the necessary experience and training to safely access the utility’s network for the purposes of tracing a subsurface utility. Then they are audited every year to ensure their skills and expertise remain current. NULCA can help you in confirming that a locator can do the job at hand.

Evidence needed to prove asset location

Locating subsurface utilities is based on AS5488-2013, Quality Level B (QL-B), supplemented by Quality Level C (QL-C) and Quality Level D (QL-D) information that relies on utility owners and operators providing evidence their subsurface utility exists.

Without this crucial piece of information, the utility locator is looking for a needle in a haystack and need to pull on all of their experience to confirm or dispute the utility exists to fulfill their duty of care, ensuring any misinformation does not result in a potential utility strike.

For public utilities, the most common method to determine the presence of subsurface utilities is by conducting a Dial Before You Dig (DBYD) search. As the essential first step, DBYD is a portal to which all utility asset owners and operators should be using to provide the public with information about their utility. It is the responsibility of the asset owner/operator to provide up-to-date information to the public (preferably through a DBYD search), however there are currently no guidelines to classify this information.

It is only through industry practice that Essential Services Plans are considered as baseline data and as such classified as Quality Level D (QL-D) to AS5488-2013. To date, Telstra and Optus are the only asset owners who have classified their data as Quality Level D to AS5488-2013.

A DBYD search for utilities privately owned and operated may not return any information. As such, it is the responsibility of the private entity or consortiums to maintain up-to-date utility data and control the quality of data delivered.

Typically, utility locators utilise the provided information to mark the ground where a utility is located, providing a depth with coloured paint applicable to the utility being investigated. This information can be surveyed with the attributes and metadata conveyed in accordance with AS5488-2013 and provided for inclusion into the design process to determine potential clashes and identify further utility investigation to
validate the utility by Non-Destructive Digging (NDD) potholing.

Minimising risks in the design stage

All too often, utility locators are engaged to investigate subsurface utilities too late in the design process. Commercial decisions and a lack of education about the importance of locating subsurface utilities usually result in shifting the risk and responsibility to obtain accurate subsurface utility information down the line, and not fulfill their due diligence or legislative obligations during the design stage. The design stage represents an opportunity to mitigate potential utility clashes by understanding the location of utilities prior to commencing the works on site.

Simply tracing unclassified utility data into a digital form such as AutoCAD and assigning typical depths of each utility from design codes is not an accurate method of depicting the location and depth of an existing utility for the purposes of mapping subsurface utilities. This philosophy usually results in a utility clash that remains unresolved prior to commencing on site and may cause a utility strike or near miss.

Every utility clash, strike or near miss that occurs in Australia is attributed to a combination of poor or misinterpreted asset owner plans and a lack of due diligence to locate a utility prior to design and construction activities as outlined in the Code of Practice for construction work and excavation work.

Avoiding costly consequences

While the severity of these incidents is usually measured by the human injury costs, the overall realistic costs of damaging subsurface utility assets from inaccurate information are often overlooked. Surrounding entities are often disrupted as a result of evacuations, repairs and downtime to the damaged utility. Increased costs and time delays of the construction project and associated flow on effects to surrounding entities and the economy are also experienced.

Utility locators provide an essential role in the identification and protection of subsurface utilities in our society. With the introduction of NULCA and the Locator Certification, the industry has come a long way in ten years.

With the updated Construction and Excavation Codes of practice and the AS5488-2013 becoming common knowledge for the identification, collection and conveyance of subsurface utility information, the public has the assurance that the companies involved in design, construction, property management and utility locating have the necessary knowledge to locate and protect subsurface utilities.

Bruce Potter is a Standards Australia, Subsurface Utility Engineering committee member (IT-036), who represented Engineers Australia in the development of the original Australian Standard AS5488-2013 Classification of Subsurface Utility Information (SUI) and is a current committee member of the AS5488 upgrade. He is a Certified Engineering Technologist (CEngT) experienced in all aspects of civil engineering and utility design, and a specialist in the field of Subsurface Utility Engineering, encompassing professional utility coordination, utility data management, field data gathering and utility asset management.

Charlotte Pordage is Editor of Utility magazine, a position she has held since November 2018. She joined the team as an Associate Editor in October 2017, after sharpening her writing and editing skills across a range of print and digital publications. Charlotte graduated from Royal Holloway, University of London, in 2011 with joint honours in English and Latin. When she's not putting together Australia's only dedicated utility magazine, she can usually be found riding her horse or curled up with a good book.

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