What is a PRB?

A permeable reactive barrier (PRB) is a technology designed for passive in situ treatment of contaminated groundwater. Also known as permeable reactive treatment zones (PRTZ), these barriers are used to intersect with the contaminant plume. When necessary, an impermeable wall is installed to direct the flow of groundwater through the PRB. The barriers are comprised of reactive materials that target dissolved phase contaminants as the plume flows through the barrier.

PRB Services

Cascade provides PRBs utilizing either liquid or solid slurry amendments.

When liquid amendments are selected for a project, they are injected into the subsurface using injection wells or direct push technology (DPT).

When solid amendments are chosen, we create the PRB using pneumatic or hydraulic fracturing, which creates a matrix by which the amendment slurry can contact the areas of contamination.

PRB Technologies

  • In Situ Chemical Reduction (ISCR)
  • In Situ Bioremediation (ISB)
  • In Situ Chemical Oxidation (ISCO)
  • In Situ Stabilization (ISS) through Carbon Sequestration

PRB Applications

  • Cut off of Contaminant Flux to Sensitive Receptors including
    • Chlorinated Solvents: PRBs utilizing zero valent iron (ZVI) or bio amendments like emulsified oils
    • Benzene, MTBE: PRBs utilizing solid oxidants like potassium persulfate
    • Hazardous Metals: PRBs utilizing ZVI or bio amendments like emulsified oils
  • Treatment of Large Plumes through Multiple PRBs
    • Chlorinated Solvents: PRBs utilizing ZVI or bio amendments like emulsified oils
  • Combined Spatial Remedies for Chlorinated Solvents including
    • Thermal for source zone and PRB for the plume
    • ISCO for source zone and PRB for the plume
    • Excavation for source zone PRB for the plume

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