ORIN successfully treated chlorinated solvent contaminated groundwater utilizing pilot-scale in-situ chemical oxidation at an active manufacturing plant facility. Contaminant levels were reduced from 710 ug/L to non detect over a two-month period. ORIN’s approach saved the client approximately $120K over traditional remediation approaches.

Site Characteristics

  • Site: Active manufacturing plant near Albion, MI.
  • Geology: Course to fine sand with gravel lenses.
  • Groundwater velocity: variable (10-2 to 10-4 cm/sec)
  • Contaminants:
    • 40 ug/L Tetrachloroethene
    • 710 ug/L Trichloroethene

Remediation Approach

  • Treatment chemistry: Potassium permanganate (KMnO4).
  • Treatment application: Chemical injections through a series of direct push points.

Chemistries used during injection

Permanganates have been shown to reduce levels of chlorinated solvents in bench contaminant without the formation of intermediate compounds commonly found with biodegradation. A benefit of a permanganate remediation approach is the complete reaction of the contaminant without the formation of intermediate compounds commonly found with biodegradation.

For example, the breakdown of TCE with potassium permanganate is as follows:

  • 2KMnO4 + C2HCl3 → 2MnO2 + 2K+ + 3Cl- + H+

Summary of In-situ Implementation

The chemistry was designed for the oxidation of chlorinated solvents (PCE, TCE and degradation products) in the groundwater at the site. Twenty-two injection points (21,460 gallons of 2% KMnO4) were completed throughout the impacted area. Evidence of oxidant influence was observed during the injection by the increase of key groundwater parameters such as DO, ORP and conductivity in monitoring wells within the targeted plume area.

Effectiveness

Six months following this pilot study injection, monitoring wells were purged and sampled for VOC constituents. Average CVOC concentrations were reduced from 710 ug/L to 206 ug/L within the targeted plume area.

The Bottom Line

ORIN successfully reduced contaminant levels below target goals by injecting permanganate chemistry through a series of direct push injections over a two-day period. ORIN’s approach reduced full-scale costs by $520K and shortened project timeframe by years over traditional remediation designs.