N.H. Code Admin. R. Env-Or 602.17
“Natural attenuation” means a reduction in the mass, toxicity, mobility, volume, or concentration of contaminants by physical, chemical, or biological processes without human intervention.
Source. (See Revision Note at chapter heading for Env-Or 600) #8812, eff 2-1-07; ss by #10831, eff 6-1-15(from Env-Or 602.12) (from Env-Or 602.15); ss by #14419, eff 11-4-25, EXPIRES: 11-4-35