Sustainable Green Remediation Saves Time And Money

CL-Out Bioremediation Site Wins Green Remediation Recognition

Sustainable, green remediation is recommended to reduce the environmental impact of the removal of existing soil or groundwater contamination.  It has the added benefit of reducing costs and accelerating remediation to save time.

Following the ASTM standards greener remediation best management practices, Irwin Engineering saved time and money for their client in the removal of nitrate and perchlorate contamination using CL-Out bioremediation.  Most of the savings came from switching from ground water extraction and treatment using ion-exchange to in situ bioremediation.

Using best management practices saved the following amount of money:

  • Reused existing piping and structures – saved $10,000.
  • Switched from ground water extraction for thermal treatment to in situ bioremediation – saved $2-3 million.
  • Close delineation and remediation planning to reduce treatment volumes – saved $1-2 million.
  • On-site biological treatment of well development water – saved $15,000.
  • Used ion specific probes to optimize lab performance – saved $20,000.
  • Used vegetation testing to delineate plume in the wetland – saved $50,000.
  • Used horizontal wells for bioremediation injection where appropriate – saved $30,000.

Overall project savings $3 to $5 million.

Overall time savings 3 to 5 years.

The property was sold to a new owner and transferred without impairment.

Click here for more project details and insights.

Click here for more information about Irwin Engineering and their award for greener remediation.

 

CL-Out Bioremediation of Groundwater in Clay Soils

Successful In Situ Remediation in Low Permeability

CL-Out bioremediation of groundwater in clay soils reduced concentrations of PCE and TCE at a former dry cleaners in Illinois.  In just over 2 weeks after injection, CL-Out microbes cut the contaminant concentrations in half.

  • PCE from 62.2 to 25.6 mg/L
  • TCE from 11.2 to 6.0 mg/L
  • Cis 1,2-DCE from 3.8 to 1.2 mg/L
  • Vinyl chloride less than 0.001 mg/L before and after treatment

The remediation continues as the microbes grow and cometabolize the residual contamination.  Even in tight clay soils the aerobic cometabolism remediates dry cleaning solvents without producing vinyl chloride or other dangerous by products.

Contact us for a free assessment of your site for bioremediation.

Photographs of Field Applications of Bioaugmentation

These photographs show actual field applications of CL-Out and Petrox.

CL-Out and Petrox are typically packaged in drum liners for convenience.

The hydrated microbes are staged typically for 12 to 24 hours prior to application.

Hydrated microbes are transfered from the drum to the contaminated media for treatment.

CL-Out and Petrox are provided in bulk bags for hydration in tanks larger than 55 gallons.

Hydrated micorbes may be applied to the surface and blended into contaminated soil.

The hydrated microbes may be injected into soil or ground water for in situ treatment.

Blending in the micorbes can also increase available oxygen.

 

Nitrate and Perchlorate Bioremediation in Ground Water

In Situ Nitrate and Perchlorate Bioremediation Eliminated Pump and Treat and Ion-Exhange Treatment Cost 

Site closure reached in less than half the projected time and cost

CL-Out® bioremediation was implemented at a confidential manufacturing site to remediate nitrate and perchlorate concentrations in soil and ground water.  The consultant installed a pump and treatment system that was operated for several years in immediate response to the discovery of contamination. While perchlorate was  the primary contaminant,  the ion-exchange resin became quickly saturated with nitrate, which was present at much higher concentrations than the perchlorate.  After review of various options and completion of a bench-scale test, the consultant implemented in situ CL-Out bioremediation to reduce the on-going cost of ground water extraction and treatment.

One of the key factors in CL-Out® cometabolism of perchlorate at this site was that CL-Out® organisms were able to reduce sequentially the oxygen and nitrate prior to perchlorate. The initial nitrate concentrations were  much higher than the perchlorate concentrations and pre-maturely saturated the ion-exchange resin. The perchlorate concentration did not decrease until the nitrate concentration decreased to less than the perchlorate concentration. One of the benefits of the CL-Out® organisms was this ability to utilize these different electron acceptors.

The initial application of CL-Out to the soil reduced the perchlorate source concentration.  After eight months of ground water bioremediation, the perchlorate concentration in the unconsolidated aquifer decreased from 128 mg/L to 3.4 mg/L immediately down gradient of the source area and from 220 mg/L to 39 mg/L farther down gradient.

Simultaneously, the CL-Out® microbes also removed the nitrate. Down gradient of the source area the nitrate concentration decreased from 105 mg/L to <1.0 mg/L.  Farther down gradient the nitrate concentration decreased from 200 mg/L to 5 mg/L.

The in situ nitrate and perchlorate bioremediation provided immediate risk reduction and mitigated potential off-site migration. The bioremediation contaminant levels to the remediation target in 3 years.  Bioremediation saved 5 years of projected treatment time and millions of dollars in OM & M costs.  The owner sold the property without environmental impairment upon completion of bioremediation. View the full case study  or  a slide presentation.

Project Consultant Received Green Leadership Award

The Massachusetts Department of Environmental Protection awarded Irwin Engineering of Natick, Massachusetts the 2016 Greener Cleanup Leadership Award for the innovative in situ bioremediation of perchorate contamination of soil and ground water at the Concord Road Site in Billerica, Massachusetts. The award honors LSPs and their clients for promoting greener cleanup principles and practices to reduce the overall net environmental footprint of hazardous waste site cleanup response actions under the Massachusetts Contingency Plan.  Read more…

Click here for more information about Sustainability and Green Remediation.

Click here for more information about CL-Out bioremediation.

 

 

Aerobic PCE Bioremediation

CL-Out Aerobic PCE Bioremediation Pilot Study Results

A CL-Out bioremediation pilot study confirmed that aerobic PCE cometabolism removed dry cleaning solvent contamination from ground water.  The pilot study was located at a former dry cleaners.  At the site, the PCE in ground water was 27 parts per billion (ppb).  Bioaugmentation introduced CL-Out microbes and dextrose as the metabolic substrate by injected into the ground water up gradient from the sentinal monitoring well.  After 30 days the PCE concentration decreased to 20 ppb.  After 6 months the PCE concentration decreased to 16 ppb.

As the PCE was decreasing, the site conditions stayed aerobic.  The dissolved oxygen level in ground water decreased from 1.07 to 0.71 mg/l.  Meanwhile,  the ORP decreased from 99 to 45 mv.  These aerobic aquifer conditions support the conclusion that the PCE removal was through aerobic bioremediation.

CL-Out cometabolism uses a dioxygenase enzyme that is produced constituatively as the metabolic substrate is consumed.  The dioxygenase enzyme destabilizes the carbon bond in the PCE to convert the molecule to an organic acid that leads to complete mineralization. Click here to view the PCE and TCE cometabolic degradation pathways.

CL-Out is a consortium of naturally-occurring microbes.  The microbes have the benefits of metabolic diversity and environmental stability.  They are non-pathogenic and safe for human health and the environment. Click here to find out more about CL-Out bioremediation.