Every excavation starts the same way: a primary investigation. An enquiry goes in, plans come back, and the paperwork says you’ve done your due diligence. It feels complete. But a primary investigation and a full investigation are not the same thing, and the gap between them is exactly where service strikes happen. Before your team breaks the surface, it’s worth asking how much of what’s actually in the ground you know, versus how much you’re assuming.
What a Primary Investigation Actually Gives You
That first step, wherever you’re digging in Australia, is a Before You Dig Australia (BYDA) enquiry: the free national referral service that identifies which asset owners have infrastructure near your site and returns their plans. Under AS 5488, the standard for classifying subsurface utility information, this is Quality Level D: information from existing records, with no verified spatial accuracy. The plans tell you who to expect underground. They don’t tell you exactly where, how deep, or whether what’s actually there still matches the records.
Where the Paper Trail Runs Out
Utility records age. Services get added, decommissioned or relocated without every change being captured. Plastic pipes and cables without a trace wire often don’t appear on owner plans at all. Depths shift with resurfacing, backfill and years of unrelated works. None of this shows up in a BYDA response, because a desktop search was never designed to answer it. So the real question isn’t whether you received plans. It’s whether anyone has confirmed, on your actual site, that those plans still reflect what’s below it.
How Far Should You Go Before You Dig?
AS 5488 sets out a path upward from Quality Level D: an on-site visual survey lifts confidence to QL-C, electromagnetic and GPR designation by a certified locator moves it to QL-B, and physical exposure by non-destructive methods like vacuum excavation confirms QL-A. Each step reduces uncertainty, but none of it happens automatically. Someone has to decide how far a given site, and a given consequence of getting it wrong, actually warrants. That’s an easy call next to a garden bed and a much harder one next to a live gas main. Where does your project sit on that scale, and who’s making that call for you?
Questions Worth Asking Before the First Cut
- Has your primary investigation gone further than a records search, or is it still sitting at Quality Level D?
- Do you know which services near your site are metallic and traceable, and which are plastic, unmarked or simply undocumented?
- If your excavation plan changes on site, has anyone re-verified the affected area, or are you still working off the original enquiry?
- Who carries the responsibility if a service is struck: whoever submitted the BYDA enquiry, or whoever put the machine in the ground?
- Is whoever confirmed what’s underground actually certified to do it, or just experienced?
Why the Certification Behind Your Locator Matters
Anyone can hold a locating wand. Not everyone is trained, tested and accredited to interpret what it’s telling them, or to know when EM locating alone isn’t enough and GPR needs to be brought in too. CERTLOC is the national certification benchmark for underground utility locators in Australia, and a CERTLOC Certified Locating Organisation employs at least one Certified Locator and works to the standards that certification demands. HCS is CERTLOC Certified, Optus Accredited, holds ISO 9001, ISO 45001 and ISO 14001 certification, and has investigated more than 2,500 sites across Melbourne, Newcastle and Brisbane. That’s not a substitute for asking the questions above. It’s who you ask them to.
Not sure whether your site has had a primary investigation or a full one? Contact the HCS team for a certified locate across Melbourne, Newcastle or Brisbane.
