Subsurface utilities were once out of sight, out of mind. But a new Australian Standard, championed by Stantec’s Rob Sansbury for nearly a decade, presents cost, time, quality and safety opportunities.
As urban regeneration projects reshape our cities, what happens underground can have an untold impact on the lives of those above ground.
Subsurface Utility Engineering, or SUE, is the management of all services, known as ‘utilities’, underground – everything from sewers and water to gas and communications.
The aim of SUE is to “comprehensively deal with underground utilities during the design phase so that they don’t cause any issues during the construction phase,” says Sansbury, Stantec’s principal civil infrastructure manager.
SUE teams combine civil engineering, geophysics, surveyance and computer aided design to provide detailed information on the location and condition of subsurface utilities. But until recently, Australia had no “rulebook” for how to design and manage subsurface utilities and was “way behind the rest of the world”.
The first Australian Standard for Subsurface Utility Information (AS5488) was released in 2013, but Sansbury says this “wasn’t very good at advising how utilities should be designed or managed”.
“It’s like learning a language – unless you all speak the same language, everyone does it their own way, in a variety of dialects. So, we ‘sort of’ understand each other, but there are just too many gaps in the process.”
The first standard “felt like unfinished business, because it didn’t deal with the core issues from the perspective of a design engineer”, he adds.
The standard was upgraded in early in 2019 to include a second part covering SUE, which was authored by Sansbury. Now, after comprehensive industry feedback, the “re-revised” version will be released before January 2022.
Without an industry-accepted standard for the management of subsurface utilities, responsibility for underground services usually rests with contractors and constructors of the infrastructure and not the designers or utility authorities.
The results can be “catastrophic”. Sansbury points to one international horror story: a construction crew disturbed an unknown underground gas line in Rochester, Michigan, causing an explosion that killed one person and hospitalised 17 more.
While lives may be at stake, and safety is always our greatest priority, the primary reason for investigating SUE design considerations is to reduce costs. The return on investment is clear. One Canadian study found each $1 invested in SUE upfront delivered a $3.41 return. Another from the US found $22.21 was saved for every $1 spent on SUE.
On large infrastructure projects, the consequences of ignoring SUE are often borne by the taxpayer who must pay for the risk the contractor prices into the project. “This can amount to billions of dollars in compensation.”
AS5488-2019, as the standard is now known, is now one of six globally, joining counterparts in the USA, UK, Canada, Malaysia, and Ecuador. Sansbury says international experts have praised Australia’s standard as the most robust and comprehensive. “We took the best from everywhere else in the world and put it into one document,” he says.
Sansbury feels a great sense of satisfaction that the “loop has been closed, with the release of the latest version of AS5488, parts one and two”.
“It has been something of a personal crusade. I've worked in many different countries and continents over 27 years. I’ve learnt there is no silver bullet, but there are better ways of doing things and we all just have to acknowledge the dynamic nature of our working environment and hence the need to keep up to speed.”
What's next? “We need one of Australia's road authorities to mandate the standard. Once one does the others will follow. It feels like we are standing on the edge of a cliff. We just need the nudge and then we will fly.”
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