When dealing with serious contamination of greater extent, at sites of complicated background, or with a complex pollution, the risk assessment is always followed by the feasibility study comparing proposed remediation alternatives and considering their technical, economical, and socio-economical criteria (legislation aspects, land-use limitations, operational safety risk assessment, etc.). The outcome is the choice of optimal technological solution that can bring an acceptable result with a reasonable costs. 
The feasibility study is a tool quite appropriate for the selection of the optimal remediation methods or the combination thereof.