1. In-situ bioremediation: In this process, the bioremediation takes place in the subsurface like the groundwater or soil. Some advantages of this type are lower costs, total elimination of the contaminants, and lower risk factor to those around it. This is also less invasive with limited human involvement. That said, the surrounding environment can impact the ability to transform the hazardous materials, and it hast to be monitored closely and consistently.
2. Ex-situ bioremediation: An alternative to in-situ, this process puts the tainted soil in above-ground treatment area and eliminates contaminants using the indigenous microbial population. The result is ideally water and carbon dioxide. Oxygen is a very important part of this process as it is key to the growth of the good bacteria, so the excavation methods are therefore that much more important. This method has proven time and again to be effective but is not as versatile as it may not work on certain metals and soils.