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Oklahoma City, Oklahoma


Oklahoma City, Oklahoma


Separate-phase hydrocarbons (SPH) in 13 wells ranging in thickness from 0.08 to 7.10 feet and covering ~8,500 ft2 . The SPH thicknesses were increased +47% and enlarged/mobilized by a prior surfactant remediation firm.


Lithology is predominantly silty clay, silt, and siltstone with some sand lenses. Groundwater is present at approx. 5 to 10 feet bgs.


SPH is absent following its removal after 57 days (34 field days) of EcoVac remediation. The site is currently in closure monitoring.

EcoVac Services was retained to remove SPH at the subject site after a prominent surfactant remediation firm, who had guaranteed removal of SPH (at a cost of $291,270), failed to do so.  The surfactant remedial efforts of the prior firm exacerbated the plume, increasing SPH +47% as well as mobilizing/enlarging the SPH plume. SPH covered an area of approximately 7,200 ft2 and ranged in thicknesses from 0.15 to 5.28 feet in nine wells prior to the previous firm’s remediation efforts.  Post remediation efforts by the other firm resulted in the SPH plume increasing to approximately 8,500 ft2 (+18%), aggregate SPH thickness increasing +47%, and SPH appearing in four additional wells.  Their remedial efforts also left an in-situ emulsion.

The previous remediation firm proposed an additional $310,337 expenditure (excluding the cost of 40 additional treatment wells) after its failure to remove SPH at the site.

EcoVac Services was retained to implement its patented SURFAC® process to remove all SPH and in-situ emulsion from the site.  EcoVac’s guaranteed cleanup cost, utilizing the existing wells, was $279,500.


The site is underlain by silty clay, silt, and siltstone, with occasional sands lenses. The groundwater table fluctuates from 5 to 10 feet bgs. The contamination (smear zone) lies between just below ground surface (bgs) to approximately 20 feet bgs.

Treatment Methodology

EcoVac Services was contracted to implement SURFAC® at this site due to failed remediation activities of the previous firm.  EcoVac Services’ patented SURFAC® process is the combination of dual-phase/multi-phase extraction and surfactant injection. EcoVac Services typically employs its EFR® (enhanced fluid recovery) process for the dual-phase/multi-phase extraction component of EcoVac Services’ patented SURFAC process. The process described herein is patent protected and represents the intellectual property of EcoVac Services, Inc.

 SURFAC® Implementation

EcoVac implemented SURFAC® utilizing the existing well network (as opposed to the 40 additional treatment wells that were recommended by the prior surfactant remediation firm that failed at this site).  EFR® was initially implemented to reduce the SPH thickness and reduce the area of hydrocarbon contamination. SURFAC® was thereafter implemented to completely remove the SPH.

 Results and Conclusions

The SPH and in-situ emulsion were completely removed from site within 57 calendar days (34 field days) of implementation at a cost of $279,500 (Guaranteed cleanup contract). SPH has been completely removed and the site in closure monitoring.

Below Images: SPH Thickness Countour Map (2007)

                        SPH Thickness Countour Map Post-Flush (2008)


Oklahoma City, Oklahoma

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