Attenuation capacity

In summary, the new methodology for soil HMBC demonstrated that the metal toxicity attenuating capacity of solids such as soils and minerals can be rapidly determined, with the entire procedure taking only a few hours, as compared to weeks required for soil column studies. 

Chapelle F. H. and Bradley P. M. (1998) Selecting remediation goals by assessing the natural attenuation capacity of groundwater systems. Bioremed. J. 2, 227-238. 

In recent years there has been a trend away from numerous, small disposal sites toward fewer and larger sites. The size of a disposal site should be based on the attenuation capacity of the geologic material, which has a finite, though generally not well-defined, limit. For slowly degradable wastes, engineered sites with leachate-collection systems appear to be only a temporary solution since the leachate collected will also require final disposal. 

Investigation of the waste attenuation characteristics of geologic materials is now one of the major ireas of research. Attenuation capacity is the material s ability to remove contaminants from percolating fluids. Approximations of the attenuation capacities of some geologic materials are known for some contaminants in leachates. These approximations provide the general relationships and principles on which judgments can be made however, it probably will be a number of years before the mechanisms of attenuation are fully understood 2md the attenuation characteristics of most geologic materials for various contaminants and combination of contaminants are known. 

The capacity of the geochemical mechanisms in the geologic materials to renovate contaminants from leachates is finite and, if exceeded, will allow the leachate to pass with little change. Therefore, the attenuation capacity of the site s geologic materials must be the limiting factor for volume of wastes for disposal. 

For both hazardous and municipal wastes, there has been a trend in recent years from numerous, widely dispersed, small disposal sites to few and larger sites. This strategy should be used with extreme caution, especially if both large and small sites are judged by the same design standards. The authors believe that the use of performance standards rather than design standards are essential under these circumstances. The attenuation capacity of any geologic materials has a limit which, if exceeded by the volume of leachate that enters the material, will allow contaminants to pass almost unretarded. Unfortunately, there are insufficient data on the attenuation capacities of... 

A wide range of urban, industrial and agricultural practices can, if not properly managed and controlled, generate significant pollutant pressures, and if the natural pollution attenuation capacity of the shallow subsurface is exceeded, groundwater pollution often results. 

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