Bioremediation of Industrial Fill

Historical industrial sites often have deposits of fill material containing a wide range of organic contaminants.   Perched ground water  present in the base of the fill is usually impacted by the contaminants and may provide a mechanism for off-property migration of the contaminants.  The organic contaminants are wide spread throughout the fill without a well defined source area.  Cost-effective remediation is difficult with this combination of conditions.

Bioaugmentation with CL-Out or Petrox can remove the contaminants from the fill and perched water by destruction in place.  The organisms in CL-Out and Petrox can metabolize a wide-range of organic chemicals at concentrations from separate-phase layers to part per trillion levels.  Soil and ground water contaminants are addressed simultaneously though injection of the microbes without disturbing the  site operations.

The following table shows typical results from a single application of Petrox to contaminated soil and perched ground water on July 10, 2011.  The remediation progress was tracked by ground water monitoring because it was the easiest sampling method once wells were in place.Industrial Fill TreatmentThe results show that within 30 days the contaminant concentrations in perched water were reduced by 50%.  After 60 days there was slight rebound in come of the contaminants, showing that more soil treatment may be necessary if lower cleanup goals needed to be maintained.



Vermont Dry Cleaner Remediation Using CL-Out

Cl-Out bioremediation was used to remove PCE from ground water at a dry cleaners in Vermont.  CL-Out micorbes were selected for bioremediation of the site because they are compatible with the natural aerobic aquifer conditions.  One application of CL-Out bioaugmentation reduced the PCE concentration by 90% in less than 6 months without increasing the vinyl chloride concentrations.

The following table summarizes the process of aerobic cometabolism of PCE.  The pre-bioaugmentation sampling showed aerobic conditions and a low population of Pseudomonas microbes.  After bioaugmentation the Pseudomonas population was higher.  As the microbes consumed the dextrose substrate and produced the oxygenase enzymes necessary for PCE destruction, the ORP and PCE concentrations decreased.  Six months after the bioaugmentation, the microbial population returned to the pre-bioaugmentation conditions.

Aerobic CL-Out Cometabolism Tracking

Improve Soil Flushing and LNAPL Removal with Petrox EC

Petrox EC is a product that combines a surfactant with petroleum-degrading microbes to improve separate phase oil recovery and bioremediation of residual oil.  The combined approach improves the rate of oil removal from soil and other subsurface media and establishes a beneficial petroleum-degrading microbial population that will treat tightly bound or deeply penetrated oil.

Petrox EC has been used in combination with periodic LNAPL extraction by pumping or bailing.   In field applications the surfactant effect has increased the LNAPL recovery rate by more than 10 fold.

Petrox EC has also been used to improve the efficiency of air sparging by flushing oil from the sediment surface for sparging and vapor phase recovery.

Field Bioremediation Rates For Petroleum and Solvents

The success of bioaugmentation depends on effective distribution of the beneficial microbes.  If the target population is achieved, the remediation rate ranges from 50% to over 99% removal.  The rate appears to be independent of the contaminant starting concentrations.  This indepedence is the advantage of bioaugmentation.  Through bioaugmentation the density of beneficial organisms is sufficient for frequent reactions with high or low contaminant levels.  The following chart shows the results of a single application of bioaugmentation at 11 sites in different states, with different contaminants.

remediation rates with bioaugmentation


The chart also suggests that the results are not time dependent.  The apparent time independence may be because the reactions are completed early and because these were grid applications with the monitoring locations within the bioaugmented area instead of downgradient where the results would depend on dispersion rates.

The USEPA tested the degradation rate of oil using Munox SR for NCP listing.  The degradation rate exceeded most comparable products with 95% removal of alkanes and 89% removal of aromatics in 28 days.  The NCP test results are available at


Bioaugmentation to Improve Oxygen Delivery Results

Many times oxygen is injected to improve natural attenuation of petroleum and other contaminants.  The results are often less than expected because the beneficial microbes that the oxygen addition is supposed to stimulate are absent or insufficient in numbers.  Bioaugmentation has been used to improve the results once the oxygen levels have increased but failed to improve the remediation rate.

The following table shows the results of Petrox bioaugmentation at a site in New Hampshire where the operation of an iSOC oxygen-delivery system failed to achieve stimulated bioremediation.  The table shows the improvement of the degradation rates and the achievement of reaching remediation goals.

Contaminant Pre-iSOC After iSOC Installation After Petrox Application
3/19/2002 1/9/2003 11/29/2004 2/9/2005 4/22/2005
Benzene 33 34 163 27 <2
Toluene 36 13 143 13 <2
Ethylbenzene 130 29 167 29 <2
Total Xylenes 500 141 336 109 <2
MTBE 60 24 61 35 1
Naphthalene 320 196 58 17 <2
1,2,4-Trimethylbenzene 110 40 238 110 <2
1,3,5-Trimethylbenzene 54 29 25 16 <2