Published 5 October 2026 · GeoRadar Australia
If you work with engineers, councils or asset owners, you'll hear it in specs and tender documents: "locations to Quality Level B", "pothole to Quality Level A", "AS 5488 compliant". Here's what the standard actually says, what each level means on the ground, and how to decide what your project needs.
What AS 5488 actually is
AS 5488 is the Australian Standard for the Classification of Subsurface Utility Information. It doesn't tell you how to dig - it tells everyone on a project how much to trust the information you have about what's underground, by grading it into four quality levels, from D (lowest confidence) to A (highest).
That grading matters because underground information comes from very different sources. A line on a 30-year-old plan and a service you've physically exposed and measured are not the same thing - and the standard stops anyone treating them as if they were.
The four quality levels, from lowest to highest
- Quality Level D - information from existing records alone, such as Dial Before You Dig plans. Useful for planning, but positions are approximate and depths are usually missing.
- Quality Level C - records reconciled against visible surface features on site: pits, valves, markers, meters. Better, but still inferred rather than measured.
- Quality Level B - services detected and traced with geophysical equipment: electromagnetic locators and ground-penetrating radar, with position and depth marked on the ground. This is what people usually mean by a professional locate.
- Quality Level A - the asset is physically sighted, usually by non-destructive hydro excavation potholing, and its exact position, depth, size and condition are confirmed by eye and measurement. This is the highest confidence the standard recognises.
Which level does your project need?
A practical rule of thumb from the jobs we do every week: plan at D, design at B, and dig at A near anything you can't afford to hit.
For excavation away from known services, a Quality Level B locate across the work area tells your crew what's there and how deep. The moment your design puts a trench, bore or footing near an existing asset - a road crossing, an intersecting main, a fibre run - the critical points should be lifted to Quality Level A by potholing, so the machine operator is digging around something they can see, not something they're trusting a plan about.
That's also why many asset owners and tier-one contractors now write Quality Level A into their permit conditions for work near their infrastructure. It isn't box-ticking: a service can sit 50mm under the surface where the plans suggest half a metre, and the repair bill on a damaged fibre route can run past $100,000 before anyone counts the delay.
Getting A and B in one visit
Quality Level B needs certified locators with electromagnetic and GPR equipment. Quality Level A needs vacuum excavation. Most providers offer one or the other; because GeoRadar runs both the locating gear and its own vac truck fleet, one crew can locate your site to Quality Level B, pothole the critical points to Quality Level A, record depths, and backfill - in a single visit, with one report at the end.
If a spec in front of you calls up AS 5488 and you're not sure what it's asking for, send it to us - reading them is part of the job, and the advice is free.