The Bodhi Group advocates monitored natural attenuation if the source contamination is no longer present and residual concentrations are amenable to MNA. Containment is also a preferred approach with capping and institutional controls as part of the remedy selection. As a last resort, active efforts may be considered, including in-situ treatment or removal.

Steps for remedy selection include:

  • Site characterization and conceptual site model
  • Source contamination presents imminent threat to human health and the environment
  • Containment – cap in place, chemical isolation, grout curtains, institutional and engineering controls, land use covenants, and covenants to restrict use of property (soil and groundwater), vapor intrusion mitigation measures
  • In-situ injection of chemical oxidation or reduction agents to reduce chemicals of concern to less toxic breakdown products
  • In-situ injection to promote anaerobic reductive co-metabolic dechlorination of solvent plumes in groundwater
  • Source removal by excavation for off-site disposal
  • On-site source removal, treatment, and reuse