Natural attenuation groundwater

Van der Meer JR, C Werlen, SF Nishino, JC Spain (1998) Evolution of a pathway for chlorobenzene metabolism leads to natural attenuation in contaminated groundwater. Appl Environ Microbiol 64 4185-4193. 

The primary action in this alte mative is capping of one or more contaminated areas (such as Areas 1 and 2 of Figure 16.21) and then natural attenuation of the contaminated groundwater. The cap would be consistent with the state RCRA (which is more stringent than the Federal requirement) landfill closure requirements. 

Two assumptions about the surface have been made to determine the effect of natural attenuation on the contaminated groundwater. First, despite the fractured nature of the bedrock, it has been assumed that the subsurface is homogeneous so as to facilitate the evaluation. Second, the potential for reduction in TCE concentrations has been assessed using a hydrogeologic model in which the fact that the cap would reduce existing leachate production by 75% is taken into account. This model is assumed to predict that the concentration of TCE in the groundwater would be reduced to an excess cancer risk level of 28 pg/L in 60 yr and an excess cancer risk level of 5 pg/L, approximately equal to the MCL, in approximately 100 yr. 

Alternative 2 achieves protection by preventing exposure through capping and natural attenuation of the contaminated groundwater. Alternative 3 combines treatment to reduce the risk from the TCE-contaminated soil and groundwater and capping of the lead area. Alternatives 4 and 5 reduce risks posed by all portions of the site through treatment. 

Natural Attenuation of Asymptotic Gasoline-Range Hydrocarbons in Groundwater... 

Barker, J. F. and Patrick, G. C., 1985, Natural Attenuation of Aromatic Hydrocarbons in a Shallow Sand Aquifer Groundwater Monitoring Review, Vol. 7, No. 1, pp. 64-71. 

Odermatt, J. R., 1997, Setting Rational Limits on Natural Attenuation Soil and Groundwater Cleanup, February-March, pp. 30-33. 

Wiedemeier, T. H. and Pound, M. 1, 1998, Natural Attenuation can be an Option for Chlorinated Solvents Soil and Groundwater Cleanup May, pp. 34-36. 

Richmond, S. A. Lindstrom, J. E. Braddock, J. F. Assessment of Natural Attenuation of Chlorinated Aliphatics and BTEX in Subarctic Groundwater. Environ. Sci. Technol. 2001, 35, 4038-4045. 

Natural attenuation, often called intrinsic remediation, intrinsic bioremediation, bioattenuation, or monitored natural attenuation (MNA) is an in situ treatment technology for soil, sediment, or groundwater. The technology has been used for full-scale remediation of sites contaminated with volatile organic compounds (VOCs), total petroleum hydrocarbons (TPH), chlorinated solvents, explosives, inorganics, and metals. 

Natural attenuation refers to naturally-occurring processes in soil and groundwater that act without... 

Maryland Supeifund Site Natural attenuation enabled new development at 70-acre Superfund site approximately 20 miles northwest of Baltimore, Maryland. This property had been contaminated by a printed circuit board manufacturing company. According to a manager, the pump-and-treat remediation system failed to meet groundwater treatment goals, though it cost over 1 million to construct and more than 200,000 a year to operate. It was estimated that this approach could cost as much as 5 million over 10 years and would still not achieve the cleanup objectives of the Maryland Department of Environment (D17452R). 

National Academies 2000. Natural Attenuation for Groundwater Remediation, Commission on Geosciences, Environment and Resources (CGER), National Academy Press, Washington DC, USA World Wide Web Address http //www.nap.edu/ books /0309069327/html/. 

Eshete, D.W. and Chyi, L.L. (2003) Source identification and natural attenuation of arsenic contaminated groundwater in northeastern Ohio. Abstracts with Programs. The Geological Society of America, 35(6), 565. 

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