MNA is selected when any contaminant source has been removed and only low
concentrations of contaminants remain in soil or groundwater. The anticipated
cleanup time for MNA must be reasonable compared to that of other more
active cleanup methods. MNA requires less equipment and labor than most
methods, which decreases cleanup costs. However, the cost of many years of
monitoring can be high. MNA has been selected or is being used at over 100
Superfund sites across the country.