considered. Also, some highly specialized microorganisms are not capable of adapting to certain site settings. Availability of certain microorganism types (as used for bioremediation) may also be a problem. Although bioaugmentation may appear to be a perfect solution for contaminated soil, it can have drawbacks. For example, the wrong type of bacteria can result in potentially clogged aquifers, or the remediation result may be incomplete or unsatisfactory. Bioaugmentation of chlorinated solvents At sites where soil and groundwater are contaminated with chlorinated ethenes, such as tetrachloroethylene and trichloroethylene, bioaugmentation can be used to ensure that the in situ microorganisms can completely degrade these contaminants to ethylene and chloride, which are non-toxic. Bioaugmentation is typically only applicable to bioremediation of chlorinated ethenes, although there are emerging cultures with the potential to biodegrade other compounds including BTEX, chloroethanes, chloromethanes, and MTBE. The first reported application of bioaugmentation for chlorinated ethenes was at Kelly Air Force Base, TX. Bioaugmentation is typically performed in conjunction with the addition of electron donor (biostimulation) to achieve geochemical conditions in groundwater that favor the growth of the dechlorinating microorganisms in the bioaugmentation culture. Niche fitness Including more microbes into an environment is beneficial to the speed of the cleanup duration. The interaction and competitions of two compounds influence the performance that a microorganism, original or new, could have. This can be tested by placing a soil that favors the new microbes into the area and then looking at the performance. The results will show if the new microorganism can perform well enough in that soil with other microorganisms. This helps to determine the correct amount of microbes and indigenous substances that are needed in order to optimize performance and create a co-metabolism. Coke plant wastewater in China An example of how bioaugmentation has improved an environment, is in the coke plant wastewater in China. Coal in China is used as a main energy source and the contaminated water contains harmful toxic contaminants like ammonia, thiocyanate, phenols and other organic compounds, such as mono- and polycyclic nitrogen-containing aromatics, oxygen and sulfur-containing heterocyclics and polynuclear aromatic hydrocarbons. Previous measures to treat this problem was an aerobic-anoxic-oxic system, solvent extractions, stream stripping, and biological treatment. Bioaugmentation has been reported to remove 3-chlorobenzoate, 4-methyl benzoate, toluene, phenol, and chlorinated solvents. The anaerobic reactor was packed with semi-soft media, which were constructed by plastic ring and synthetic fiber string. The anoxic reactor is