A technique for treating contaminated soil. For active treatment, the technique involves spreading the soil to a depth of 6 to 12 inches, over impermeable soil or an impermeable barrier. Every 2 weeks or so, this soil is aerated, typically by use of some sort of farm implement such as a harrow. The soil is also watered and fertilized, and then covered with plastic. The process results in the breakdown of petroleum contaminants in the soil.
Land farming works well with soil that has been contaminated with gasoline and other liquid hydrocarbons. For example, contaminated soil removed from a gasoline storage tank area can be subjected to the land farming process and then returned to its original site.
Environmental regulations do not always permit use of the land-farming technique. Even where it is allowed, there are often requirements that hydrocarbons released from contaminated soil be further processed before they are allowed to escape into the air.