Want to know a bit more about how Monitored Natural Attenuation works?  Click here.

Email XDD at keane@xdd-llc.com for case studies associated with our in situ remedial technology experience.


Technical expertise is important for my projects.   XDD is flexible, likable, and not expensive relative to the services they provide. Unlike some companies who do things the same way every time, XDD is very agile when confronted with changing site conditions.

Abbie K. Baker

Environmental Attorney

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Monitored Natural Attenuation

Monitored Natural Attenuation (MNA) is often a preferred option relative to active in situ remediation as it is:

  • Less invasive, especially for site with existing activities or obstructions
  • Uses existing subsurface processes such as biological/abiotic degradation, dispersion, dilution, and retardation to reduce risk.
  • Relatively lower in cost when compared to other remedial technologies

XDD has been providing MNA evaluation and sampling services throughout our history, those services include:

  • Conceptual model refinement
  • Evaluation of fate and transport within groundwater and vapor phases
  • Timeframe estimates relative to source zone properties
  • Evaluation of existing MNA pathways, such as:
    • Dispersion
    • Dilution
    • Abiotic and biotic transformations
    • Retardation
  • Site investigations and analyses to determine the magnitude of MNA processes