Remediation of PCE/TCE plume under leased building:
Combination SVE and Permanganate Injection, CT
200,000 SF Leased Building had chlorinated solvent in the unsaturated zone and in groundwater

  • The Client had owned the building, used it for manufacturing and sold it, retaining liability for environmental
    cleanup of solvents under the slab.
  • The building was leased back for a limited period at high cost, requiring schedule maximum efficiency of remedy.
  • Building has limited ceiling height (12') and a smooth concrete floor that had to be restored after SVE piping
    installation below the slab.
  • Soil conditions indicated a maximum 25 foot spacing of SVE wells; over 80 wells were constructed and plumbed
    in 3 weeks.
  • Over 50 MnO4 injection points were installed at the same time.
  • Ten storage and mixing tanks (30,000 gallons total) were mobilized and plumbed into the injection system
  • Concrete floor was repaired and two (zoned) SVE plants were installed (600 and 200 CFM).
  • Both KMnO4 and NaMn04 were injected to balance efficacy and cost; over 300,000 gallons of solution were
    injected during the 30 day period authorized by CTDEP.
  • All operations were completed on schedule.
  • During follow up evaluations, a storm drain under the building was accidentally broken and injection solution was
    discharged to a local creek. A significant emergency response was successfully coordinated over a holiday
    weekend to contain the discharge and minimize environmental impacts.
  • Groundwater monitoring indicates that the oxidant is successfully reducing PCE/TCE levels to compliance targets.