Acid sulfate soils

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

acid-sulphate-soils.jpg When disturbed or exposed to air these soils can release acid, damaging built structures and harming or killing animals and plants.

One tonne of iron sulfides can produce about 1.5 tonnes of sulfuric acid when oxidised. Significant fish kills can occur when sulfuric acid is washed into waterways.

Various techniques are used to deal with acid sulfate soil disturbances to make sure acidic discharges are not produced. Generally, soil samples are taken, the acid generating potential of the soil is calculated and the soil neutralised with agricultural lime to prevent low pH discharges.

See acid sulfate soils

Risk maps

Acid sulfate soil risk maps are available to identify potential acid sulfate areas: 

Consent and approval

Common activities such as cropping, drainage works and construction can trigger acid sulfate soils to oxidise and produce acid. Works need to be undertaken with extreme caution and in consultation with relevant authorities.  

Refer to LEP 2000 when any landform alteration may result in the disturbance of acid sulfate soil.  

Written approvals are required from Council in most cases before soils are disturbed.

Before starting any work call Council's Planning Duty Officer on 02 6670 2400 to see if any approvals are required.

Council’s Environmental Health Services can provide advice about acid sulfate soil assessment and management.

Soil testing

See Tweed Laboratory Centre

More information