Chapter 4.3 Soil pollution
Peat drainage and decomposition can cause the peat soil layer to become thinner. Several cases of peatland damage have occurred in Kalimantan. The land in these areas that have now been abandoned has high levels of acidic sulfate in the soil, which is a source of environmental pollution in the vicinity.
Peat drainage and decomposition causes the peat soil layer to become thinner. If the mineral soil layer under the peat (substratum) is a quartz or pyrite layer, then the soil becomes more acidic and has a higher risk of iron and aluminum poisoning.
Cases of peatland destruction took place in the Petak Island Delta of South and Central Kalimantan, which in 1952 was still covered by 51,360 hectares of peatland. In 1992, only 9,600 hectares of peatland remained (research by Sarwani and Widjaja Adhi, 1994). In addition to the compromised hydrological function, most of the former peatland areas at present comprise abandoned land with acid sulfate soil – a severe source of water pollution in the area.