MNA Frequent Question 10. What are some potential disadvantages of MNA?

Longer time frames may be required to achieve remediation objectives, compared to active remediation measures at a given site;
Site characterization is expected to be more complex and costly;
Toxicity and/or mobility of transformation products may exceed that of the parent compound;
Long-term performance monitoring will generally be more extensive and for a longer time;
Institutional controls may be necessary to ensure long term protectiveness;
Potential exists for continued contamination migration, and/or cross-media transfer of contaminants;
Hydrologic and geochemical conditions amenable to natural attenuation may change over time and could result in renewed mobility of previously stabilized contaminants (or naturally occurring metals), adversely impacting remedial effectiveness; and
More extensive education and outreach efforts may be required in order to gain public acceptance of MNA.