Remedial strategy focused on naturally occurring substance process to evaluate and enhance the degradation of contaminants over time.

1,4 Dioxane (14DX-1)
Section 6 (Remediation and Treatment Technologies) – Monitored Natural Attenuation
MNA is a remediation technology in which natural processes are used to achieve site-specific objectives. 

Attenuation Processes for Metals and Radionuclides (APMR-1)
Section 2.3 (Geochemical Processes), Section 6 (Table 6.1)
Discusses metal solubility, sorption, and bioavailability on metal speciation.

Dense, Nonaqueous-Phase Liquids (DNAPLs-5)
Table 4-1
Discusses natural attenuation on DNAPL sites.

Enhanced Attenuation: Chlorinated Organics (EACO-1)
Section 1.4 (Enhanced Attenuation), Figure 1-2
The entire document provides information about natural attenuation with an introduction to the process in Section 1.4.

In Situ Bioremediation (ISB-2)
Appendix B (Natural Attenuation Position Paper)
Position pager on natural attenuation.

MTBE and Other Fuel Oxygenates (MTBE-1)
Section 4.6 (Monitored Natural Attenuation), page 76-81
MNA is the reliance on naturally occurring subsurface processes to achieve site-specific remediation goals in a reasonable period of time, in the context of a site that is carefully controlled and monitored.