Acid Sulphate Soils
Acid sulphate soils often occur in areas which were once waterlogged (eg. mangrove swamps and low lying coastal areas). In these areas, when the soil is drained and exposed to air, sulphuric acid can be formed. The produced sulphuric acid moves through the soil dissolving heavy metals and making the soil too toxic for plant growth. The acid can also drain into nearby waterways, poisoning fish and aquatic life. The acid can corrode concrete, iron and steel causing the weakening of concrete buildings. One kilogram of soil can produce one and a half kilos of acid.