What is Monitored Natural Attenuation (MNA)?
Monitoring the progress of the destruction of a contaminant via natural processes (e.g. microbial consumption). It should reduce the mass and concentration of a contaminant to an acceptable level (clean-up goal) within 30-years (inter-generational equality). The process should be understood, demonstrated to be occurring at an acceptable rate, and a fall-back (contingency) plan should be provided where MNA fails to meet the remedial objectives.
