Chlorinated Solvent Plume

Migration Physics

Advection and hydrodynamic dispersion govern contaminant transport velocity through saturated porous media. Dissolved mass advances alongside the average linear groundwater flow rate while mechanical mixing spreads the front transversely and longitudinally. Sorption onto aquifer solids retards forward progress relative to the ambient fluid movement.

Retardation factors depend directly upon fraction of organic carbon values within the geological matrix. Low permeability lenses trap high concentrations through back diffusion long after the main mass passes.

Phase Partitioning

Contaminants exist simultaneously in sorbed, dissolved, aqueous, vapor and nonaqueous phases beneath the water table. Pure phase dense nonaqueous phase liquids pool at aquitard boundaries and slowly dissolve into passing groundwater. Interphase mass transfer rates dictate longevity within source zones and distal margins.

Dissolution kinetics create long term tails in concentration curves observed during field sampling events. Gas phase vapors partition upward into soil gas zones above the shallow water table.

Remediation Limits

Full removal from fractured bedrock formations remains practically impossible due to matrix diffusion limitations. Surfactant flushing accelerates desorption but introduces secondary containment risks during field injection programs. In situ chemical oxidation destroys dissolved mass upon contact yet fails to reach trapped residual pools without complete sweep efficiency.

Premature site closure occurs when monitoring wells miss high concentration zones situated between spacing networks. Mass flux reduction serves as the primary performance metric when absolute cleanup standards prove unattainable.