If you are developing land or building in coastal areas of South East Queensland—particularly the Gold Coast, Sunshine Coast, or low-lying parts of Brisbane and Moreton Bay—you may be required to complete an Acid Sulfate Soil (ASS) investigation.
What are Acid Sulfate Soils?
Acid sulfate soils are naturally occurring soils containing iron sulfides. When left undisturbed beneath the water table, they are harmless. However, when exposed to air through excavation or drainage, they react with oxygen to form sulfuric acid. This acid can severely damage concrete and steel structures, harm the environment, and kill aquatic life.
When Do You Need an ASS Test?
You typically need an ASS investigation if your project involves:
- Excavating more than 100 cubic metres of soil in a mapped ASS risk area.
- Filling land with more than 500 cubic metres of material with an average depth of 0.5 metres or greater.
- Extracting groundwater or lowering the water table.
- Developing land below 5 metres Australian Height Datum (AHD).
Your local council or private certifier will advise if an ASS investigation is required as part of your Development Application (DA). Express Soil Testing provides preliminary ASS assessments to determine if a detailed investigation and management plan are necessary.