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Del City, Oklahoma


Del City, Oklahoma


Separate-phase hydrocarbons (SPH – gasoline) in seventeen monitor wells ranging in thickness from 0.03 to 2.39 feet. The remediation area was approximately 13,900 yd3.


The unconsolidated sediments consist of clay, silty clay, sandy clay, silt, silty sand, with some sand at depth.


Groundwater is present at a depth of approximately 7 to 17 feet bgs. The hydraulic conductivity varied significantly (10-4 to 10-6 cm/s) across the site.


SURFAC® successfully removed the SPH and the site has been approved for closure.



EcoVac Services, Inc. was contracted by an environmental consulting firm (under the direction of the Oklahoma Corporation Commission, OCC) to provide removal of gasoline SPH at the U-Haul facility in DelCity, OK. The gasoline SPH plume emanated from the gasoline UST tank pit on the west side of the property, and from the fuel island on the east side of the building, as shown on the Site Map. EcoVac Services utilized its EFR® process in combination with its patented SURFAC® process to remove the SPH from the subsurface.

The object of EcoVac Services’ patented SURFAC® process was to remove all SPH from the site. 


The site is underlain by clays, silty clays, sandy clays, with occasional clayey sands lenses. The groundwater table fluctuates from 7 to 17 feet bgs. Groundwater flow rates are approximately 10-4 to 10-6 cm/s. The contamination (smear zone) lies between 5 to 18 feet bgs in interbedded clays, silty clays, sandy clays, and the thin clayey sand lenses.

Remediation Methodology

EcoVac Services was contacted to implement SURFAC® at this site due to the effectiveness and relative speed of surfactant remediation. EcoVac Services’ patented SURFAC® process is the combination of dual-phase/multi-phase extraction and surfactant injection. EcoVac Services employs its EFR® process.  The process described herein is patent-protected and represents the intellectual property of EcoVac Services, Inc. 

SURFAC® Implementation

EcoVac designed the remediation well network and provided oversight during installation. The remediation well network consisted of 18 remediation wells. Remediation field activities were then initiated on January 23, 2008 (EFR®), and continued through March 15, 2008. Table 1 summarizes the field activities by technology.

Table 1: Field Activities by Technology




January 23 to February 8, 2008



To reduce the SPH thickness.

February 11 to March 15, 2008



To remove all SPH.


EFR® was implemented from January 23 through February 8, 2008. The purpose of EFR® is to reduce the SPH thickness and reduce the area of hydrocarbon contamination. SURFAC® was implemented from February 11 through March 15, 2008. SURFAC® was implemented to completely remove the SPH.

 Results and Conclusions

SPH has been successfully removed from the site and the site has been approved for closure.




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