Natural Attenuation Monitoring is appropriate if concentrations of Contaminants of Concern , which exceed their respective cleanup levels or standards do not exceed a set of higher levels, that are designated as Natural Attenuation Default Concentrations . Natural Attenuation Monitoring is an allowable strategy for site rehabilitation with the objective being to meet the No Further Action criteria. Natural Attenuation recognizes that the spread of contamination and the reduction of contaminant concentrations in soil and groundwater can be accomplished by natural processes.

Monitoring is conducted for at least one year, and if and when contaminant concentrations decrease to levels for No Further Action, a Site Rehabilitation Completion Order can be approved.

Normal land uses can continue or be developed during Natural Attenuation Monitoring.