According to EPA(a) 'The United States is the world leader in field implementation of bioremediation, an attractive alternative to conventional methods of cleaning up persistent hazardous wastes in the environment.’ It further goes on to state, ‘The potential use of bioremediation technologies is significant, as federal & state governments, private industry and others responsible for environmental cleanup efforts add it to their arsenals of methods for environmental reclamation.

What are EPA's views on the advantages of Bioremediation?
Bioremediation is an attractive option for the remediation of hydrocarbon contaminants. The following are a few of the advantages & reasons why you should consider this innovative process.

The process is an ecologically safe and natural process.
Bioremediation is cost effective.
The process is generally 60-70% less costly than other technologies.
Little disruption of surrounding, non-contaminated areas.
Virtually no investment in “capital equipment”.
Can remediate areas that are not easily accessible or are inaccessible to other technologies.
Bioremediation can be accomplished in-place (In Situ)
Air quality and air pollution concerns from volatile chemical evaporation are eliminated.
After bioremediation is completed, the environment is virtually restored to its pristine condition.
The process poses no health or safety risks to employees thereby reducing insurance costs.

Bioremediation accomplishments
The oil spill research program has been active since the passage of the Oil Pollution Act of 1990 (OPA-90). Since that time, significant advances have been made. Most notable have been the development and promulgation of a screening protocol for confirming the effectiveness of marine oil spill bioremediation agents(1) and the statistical proof from the Delaware field study that bioremediation enhances the disappearance rate of crude oil hydrocarbons in the field despite an already high background rate.(2,3)

An outgrowth of that study was the characterization of microbial community changes that occurred during the course of the bioremediation effort.(4)The most striking change was the shift from primarily Gram(+) bacteria and eukaryotes at the beginning to predominantly Gram(-) bacteria after about 8 weeks and continuing on to the end.

Other important findings from the program have been the development of a new method of estimating separately the populations of bacteria able to break down alkanes and aromatics in crude oil,(5,6) the quantification of the minimum nitrogen concentration needed on marine beaches for maximum growth rate on hydrocarbons,(7) the definition of the frequency of application of water-soluble nutrients needed to maintain the target nitrogen concentration,(8,9) the discovery that asphaltenes inhibit the breakdown of the biodegradable constituents in crude oil,(10) and the development of new mathematical models that help explain the nutrient transport dynamics on marine beaches.(11,12,13,14) The foregoing advances have been major achievements.

Sited from EPA Bioremediation Research
Publications:

(a) 64O/k-93/002

(1) Venosa, A.D., J.R. Haines, W. Nisamaneepong, R. Govind, S. Pradhan, and B. Siddique. 1992. "Efficacy of commercial products in enhancing oil biodegradation in closed laboratory reactors." J. Ind. Microbiol. 10: 13-23.
(2) Venosa, A.D., M.T. Suidan, B.A. Wrenn, K.L. Strohmeier, J.R. Haines, B.L. Eberhart, D. King, and E. Holder. 1996. "Bioremediation of an experimental oil spill on the shoreline of Delaware Bay." Environmental Sci. and Technol. 30(5): 1764-1775.
(3) Venosa, A.D., M.T. Suidan, D. King, and B.A. Wrenn. 1997. "Use of hopane as a conservative biomarker for monitoring the bioremediation effectiveness of crude oil contaminating a sandy beach." J. Ind. Microbiol. & Biotechnol. 18: 131-139.
(4) Macnaughton, S.J., J.R. Stephen, A.D. Venosa, G.A. Davis, Y-J. Chang, and D.C. White. 1999. "Microbial population changes during bioremediation of an experimental oil spill." Appl. Environmental Microbiol. 65(8): 3566-3574.
(5) Haines, J.R., B.A. Wrenn, E.L. Holder, K.L. Strohmeier, R.T. Herrington, and A.D. Venosa. 1996. "Measurement of hydrocarbon-degrading microbial populations by a 96-well plate most-probable-number procedure." J. Ind. Microbiol. 16: 36-41.
(6) Wrenn, B.A. and A.D. Venosa. 1996. "Selective enumeration of aromatic and aliphatic hydrocarbon-degrading bacteria by a most-probable number procedure." Canad. J. Microbiol. 42: 252-258.
(7) Du, X., P. Reeser, M.T. Suidan, T. Huang, M. Moteleb, M. Boufadel, and A.D. Venosa. 1999. "Optimum nitrogen concentration supporting maximum crude oil biodegradation." In: Proc. International Oil Spill Conference, Seattle, WA, American Petroleum Institute, Washington, DC.
(8) Wrenn, B.A., M.T. Suidan, K.L. Strohmeier, B.L. Eberhart, G.J. Wilson, and A.D. Venosa. 1997. "Nutrient transport during bioremediation of contaminated beaches: evaluation with lithium as a conservative tracer." Wat. Research 31(3): 515-524.
(9) Wrenn, B.A., M.T. Suidan, K.L. Strohmeier, B.L. Eberhart, G.J. Wilson, A.D. Venosa, J.R. Haines, and E.L. Holder. 1998. "Influence of tide and waves on washout of dissolved nutrients from the bioremediation zone of a coarse-sand beach: application in oil-spill bioremediation." Spill Sci. & Technol. Bulletin 4(2): 99-106.
(10) Uraizee, F.A., A.D. Venosa, and M.T. Suidan. 1998. "A model for diffusion controlled bioavailability of crude oil components." Biodegradation 8: 287-296.
(11) Boufadel, M.C., M.T. Suidan, A.D. Venosa, C.H. Rauch, and P. Biswas. 1998. "2D variably saturated flows: physical scaling and bayesian estimation." J. Hydrol. Engineering 3(4): 223-231.
(12) Boufadel, M.C., M.T. Suidan, and A.D. Venosa. 1997. "Density-dependent flow in one-dimensional variably-saturated media." J. Hydrol. 202: 280-310.
(13) Boufadel, M.C., M.T. Suidan, and A.D. Venosa. 1999. "Numerical modeling of water flow below dry salt lakes: effect of capillarity and viscosity." J. Hydrol. 221: 55-74.
(14) Boufadel, M.C., M.T. Suidan, and A.D. Venosa. 1999. "A numerical model for density- and viscosity-dependent flows in two-dimensional variably saturated porous media." J. Contaminant Hydrol. 37: 1-20.