What to do if you are developing land containing acid sulfate soils

Acid sulfate soils are natural sediments that contain iron sulfides. They are common along the NSW coast.

These soils are harmless when left alone. But when these soils are excavated or drained, the sulfides react with the oxygen in the air and form sulfuric acid.

Sulfuric acid - together with associated heavy metals and other contaminants - can kill plants and animals, contaminate drinking water and foods such as oysters, and corrode concrete and steel.

Acid sulfate soils are typically found in low-lying areas near the coast and generally occur below the five-metre Australian Height Datum (AHD).

These soils include those that are currently producing acid and those that could potentially produce acid.

The Sutherland Shire Local Environment Plan 2015 (SSLEP) includes an acid sulfate soils map.

The map identifies five classes of land, based on the likelihood of acid sulfate soils being present in particular areas, and at certain depths.

If your development is situated in an acid sulfate soils area and is likely to impact the soil and trigger requirements under clause 6.1 SSLEP 2015, an appropriately qualified and certified environmental scientist must undertake an acid sulfate soil assessment.

This must be carried out in accordance with the NSW Acid Sulfate Soils Manual 1998 and the National Acid Sulfate Soil Guidance 2018.

The acid sulfate soil assessment and management plan (if required) must be submitted with your Development Application.

Mandatory consultant qualifications

The environmental consultant must be certified by one of the following schemes:

  • EIANZ ‘Certified Environmental Practitioner’ (CEnvP).
  • Soil Science Australia ‘Certified Professional Soil Scientist’ (SSA CPSS).