An extraction well pumps contaminated water to the surface treatment facility. Carbon filtration, aeration, lime addition, biodegradation or chemical detoxification can be utilized there to decontaminate the water. This process involves the use of bacteria to degrade contaminants to less harmless compounds. The rate of this process is affected by acclimation time. This is the time necessary before microorganisms are able to degrade contaminants.
Acclimation is accomplished by enzyme reduction, gene mutation and gene transfer.
This is usually an electron acceptor for oxidizing the contaminants. Biodegradation can occur aerobically or anaerobically. An example of biodegradation is occurring in a Gloucester, Ontario aquifer where naturally present bacteria are breaking down the contaminant trichloroethane all the way to carbon dioxide through successive dehalogenation. Depending on the type of contamination, other chemicals may be added to contaminated water that is pumped to the surface or chemicals may be pumped into the contaminant plume. This process attempts to react the contaminant with another chemical which may lead to a less harmful product.