Monitored natural attenuation of contaminants in the subsurface: Applications

In recent years there has been increasing interest in the application of pa ssive technologies to reduce or remove contaminants from the subsurface env ironment including soil and ground water. In most cases, the impetus for th is interest lies in a perceived savings compared with more traditional reme dial alternatives. In a few cases, the infrastructure at contaminated sites , such as buildings, paved areas, and utilities, makes the use of conventio nal remedial measures difficult and expensive. To demonstrate that natural processes are effective in reaching established goals, it is necessary to d etermine that transformation processes are taking place at a rate that is p rotective of human health and the environment and that these processes will continue for an acceptable period of time. The basic conditions that must be present to confirm natural attenuation processes are taking place are di scussed along with the behavior of contaminated plumes, monitoring requirem ents, data analysis, rates of degradation, and mathematical modeling.