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The Definitive Guide To Understanding As5488 Markings.


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This is the definitive guide to utility locator spray paint markings in Australia. This post is about the Australian Standard of Subsurface Site Marking Information. This standard in Australia is called AS5488. When utility locator does a service worksite mark-out in spray paint, he or she should mark in accordance with AS5488.

What is the basic code markings of AS5488? πŸ”›

When a utility locating contractor does a service mark-out onsite, he or she should mark in accordance with AS5488. The format used below is as follows, (Utility, Color and Symbol.)

  • Blue = Potable Water (W)
  • Yellow = Gas (G)
  • White = Communications (C) (or black when on white background)
  • Orange = Electricity (E)
  • Green = Drainage (D)
  • Red = Fire Hydrant Services (FH)

A fundamental understanding of AS5488

Quality Levels: AS5488 – 2013

There are four accuracy levels which are defined as β€˜Quality Levels’ in AS5488 – 2013. These range from β€˜D’ being the lowest, to β€˜A’ being the highest and most accurate.

To minimize the risk of damaging buried assets, all sub-surface measurements where shown in design or construction should have an AS5488 Quality Level defined and recorded.

Any plans and information provided by 🦺 DBYD Certified Locators following a location should indicate the Quality Level classification details of the asset locations undertaken.

The default Quality Level for subsurface information without a Quality Level specified is β€˜D’. Many Dial Before You Dig Asset Owner Members do not specify an AS5488 – 2013 Quality Level, therefore the default value of QL-D should apply.

πŸ‘· To avoid damaging buried assets when excavating the subsurface information relating to the location must be to Quality Level β€˜A’.

Examples of standard colors used to represent utilities are below.

Utility and Color: Communications: White (or black when on white background), Drainage: Green, Electricity: Orange, Fire Service: Red, Gas: Yellow, Water: Blue

Example: Power Electrical Cable 200mm depth with a AS5488 quality level of B

A In-depth look at AS5488 πŸ‘€

See below for a guide on interpreting the Quality Levels described in AS5488 – 2013.

For full details refer to AS5488 – 2013, which is available for purchase from Standards Australia.

Also you will notice a letter ( A,B,C or D) with a circle around it next to service line markings, this means and symbolizes the certainty or accuracy of that service line mark, and without this mark it doesn’t conform to AS5488 standards.

  • QLA β’Ά = Is generally a positive physical identification like a pothole.
  • QLB β’· = Is generally a positive electronic trace (EM Locator).
  • QLC β’Έ = Marked between known points like between pits and manholes.
  • QLD β’Ή = Is service was not identified but assumed mark on where it is.

Quality Level D – (least accurate level and if used on its own has a high risk of damage)

QL-D information is generally obtained from existing records provided by utilities as a result of a Dial Before You Dig enquiry being lodged. In many cases the asset depicted on the plan is in a schematic format only and intended only to indicate its presence.

Quality Level C – (low accuracy and a high risk of damage)

Is described as a surface feature correlation or an interpretation of the approximate location and attributes of a subsurface utility asset using a combination of existing records and site survey of visible evidence – for example you can see the pit lids shown on the plan but the actual position of underground connection between pits is still assumed.

Quality Level B – (significant risk reduction)

Provides relative subsurface feature locations in three dimensions. The minimum requirement for QL-B is relative spatial position, this can be achieved via an electromagnetic frequency locating device. An electronic location provided by a DBYD Certified Locator to QL-B standard would have a maximum horizontal tolerance of plus or minus 300mm and a maximum vertical tolerance of plus or minus 500mm.

Quality Level A – (meets location accuracy standards for minimum risk when excavating)

Is the highest Quality Level accuracy and consists of positive identification of the attribute and location of a subsurface utility at a point to an absolute spatial position in three dimensions. It is the only quality level that defines a subsurface utility as β€˜Valid.

❓ Understanding why AS5488 is important?

Understanding the AS5488 markings aims to help reduce damages by providing a national standard format for recording subsurface utility information.

AS5488 – 2013 aims to help reduce damages by applying an accuracy classification to measurements relating to subsurface assets. Underground measurements can be obtained from different sources and subsequently can have different levels of accuracy.

☠️ An un-classified or un-qualified subsurface measurement on its own does not indicate its accuracy.

This can lead to damages and project delays if a wrong assumption is made. By utilizing accuracy classifications (Quality Levels), others using the information can recognize the accuracy (or inaccuracy) of the information when designing and constructing and avoid conflicts and damages.

🧰 Where legislation or a regulation refers to a standard, workplace participants must comply with the standard. AS5488 – 2013 Classification of Subsurface Utility Information (SUI) has been developed to provide utility owners, operators and locators with a framework for the consistent classification of information concerning subsurface utilities.

The application of this Standard is intended to improve public safety and reduce costly property damage. 🚧

AS5488 – 2013 further helps reducing injuries and damages by, Providing a national standard format for recording subsurface utility information. This includes codes, line types and colors. Having an industry standard will reduce confusion and misinterpretation by the end users of that information.

How to Decode πŸ”£ marks from different utility locators?

Decoding a Utility Locating Mark.

Site Mark: X .3 B

X = Location Position

.3 = 300mm Depth

B = QLB Pit to Pit (Horizontal Accuracy -/+300mm/ Vertical Accuracy 500mm)

πŸ›‘ Misconceptions about AS5488

This includes codes, line types and colors. Having an industry standard will reduce confusion and misinterpretation by the end users of that information. Every country has slightly different spray paint utility color codes.

Utility Locating service will use different colors due to supply of paint on-site, or sometimes change colors for contrast on certain utility surfaces. Example would be paint White paint on black surfaces for communication lines, but black paint on white/light surfaces, to be seen easier from workers onsite.

For full details refer to AS5488 – 2013, which is available for purchase from Standards Australia. Buy AS5488 2019 Classification of subsurface utility information Subsurface utility information from InfoStore SAI Global.


AS5488 2013 spray paint markout standard infographic. Free Download. For image printout or download Click Here, For PDF version click Use it to learn the standard meanings for utility locating markouts of services with spray paint.

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