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Asbestos in the ground: buried pipe, old fill and what to do before you dig

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You cannot see it from the surface. Know where it hides and what to do the moment a spade hits something odd.

Asbestos in the ground is usually not a bare patch of soil. It is a buried product, or a layer of old fill. The two common sources are asbestos cement pipe and demolition waste that was dumped or spread as fill. And the second one is far harder to spot before you dig.

Where buried asbestos usually comes from

Three situations account for most cases on a residential block.

  • Buried pipe. Asbestos cement pipe was widely used for stormwater, sewer and water lines, and a length of it can run through a yard without any surface sign.
  • Old fill. Broken sheet from demolished sheds and houses was sometimes used as backfill or levelling material, which is how fragments end up metres below a lawn.
  • Buried sheet. Offcuts and old fence panels were sometimes buried on site rather than removed.

Why it is hard to see

Fragments in fill look like ordinary grey rubble. A pipe looks like nothing at all until a spade hits it. Nothing on the surface reliably signals either one, so you cannot rule it out by walking the block.

Age is the best clue you have. A property that has had a house, shed or fence demolished on it, especially before 2004, has a real chance of some buried waste. A block that was never built on before the ban is far less likely.

What to do before you dig

Decide before the excavator arrives, not after. Look for records: a council plan, a plumber’s drawing or a previous owner’s report can show the pipe material or a past demolition. If a pipe or fragment is exposed while you dig, stop. Do not break it, do not bag it yourself and do not keep digging around it. Keep people and pets away and treat it as compatible with asbestos.

Any confirmation comes from a sample analysed by a NATA-accredited laboratory, arranged through a properly qualified person. Rules for handling and disposing of found material are set state by state. So the WHS regulator or the environmental regulator in your state is the right place to ask. Our page on asbestos in soil covers the garden side of the same question.

When it is not worth worrying

Shallow digging for planting in a block that has never been built on is a very different situation from excavating an old demolition site. If you are not disturbing deep ground, there is usually nothing to do except stay alert. Do not commission testing of the whole yard on a hunch. Test what you actually find, or what your records tell you to check.

If you are unsure what a particular piece of material is, the is it asbestos? evidence check gives you a safe next step. And asbestos in concrete explains why buried pipe is so often the real culprit around old slabs and paths.

Frequently asked questions

Can there be asbestos in the ground on my property?

Yes, particularly where a building was demolished, where old fill was spread, or where asbestos cement pipe runs underground. It is not present on every block, and age and site history are the best guides.

What should I do if I dig up something that might be asbestos?

Stop digging, do not break or pick up the material, keep people and pets away and treat it as compatible with asbestos. Confirmation needs a sample analysed by a NATA-accredited laboratory, and the WHS regulator in your state can tell you the next steps.

Is asbestos in the ground dangerous if I leave it alone?

Intact, undisturbed material buried in the ground is generally a much lower concern than damaged material in the open. The risk rises when digging, breaking or crushing releases fibres.

How do I find out whether an old pipe on my block is asbestos cement?

Council plans, plumbing drawings and previous owner reports can show pipe material. You cannot confirm it by looking, so a laboratory result from a sample is the only definite answer.

Sources

What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.

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