Case Studies

Case Study

Groundwater Remediation
In Situ Chemical Oxidation Remediates LNAPL in Groundwater
Site: Former Mill

former mill

Table 1

Table 2

Figure 1. Site Map with RegenOx Injection Locations

Table 3

Site Summary

Originally a tannery and leather goods manufacturing facility, the Site currently operates as a large warehouse. Subsequent to the tannery operations, a plastic toy manufacturing facility operated at the Site until the early 2000’s. Injection‐molding machines using hydraulic oil were located in the basement level and are the source of contamination in soil and groundwater, including LNAPL. Subsurface geology consists of bedrock underlying two to five feet of fill material. Groundwater is present directly beneath the concrete slab as a result of recharge occurring from the bedrock aquifer. Investigations of the building infrastructure allowed for trenches in the concrete floor where LNAPL would surface as a result of rising groundwater. The zone of LNAPL was measured at 2‐4 feet in thickness. RegenOx was proposed to treat the LNAPL using injection points between the trenches.

Remedial Approach

Objective: Chemically treat LNAPL via In situ chemical oxidation using RegenOx™

Results

During the RegenOx injection events, LNAPL was desorbed from the soil and forced into the open trenches where a continued reaction and partial destruction were noted. In addition to the RegenOx application, vac‐out events were conducted and successfully removed a total of 33,232 gallons of contaminated groundwater/LNAPL.

Following the completion of the RegenOx treatment, soil borings were taken adjacent to the previous borings in order to assess contaminant concentrations. A decline of 13% ‐ 76% was observed at ten months post‐RegenOx injection.

A significant decline was observed in groundwater as concentrations of hydraulic oil were reduced by 1 to 2 orders of magnitude (Table 3). The complete removal of LNAPL was confirmed after approximately one year of monitoring.

Conclusion

RegenOx successfully treated high concentrations of hydraulic oil within the shallow aquifer, eliminating LNAPL from groundwater. Site remediation was completed within one year allowing for continued future operations.