Bioaugmentation is an in situ bioremediation process that introduces specialized microorganisms into contaminated soil or groundwater to enhance the biological degradation of contaminants. It is typically used when the naturally occurring microbial population cannot completely degrade the contaminants present at a site.
Why Bioaugmentation Matters
Many contaminated sites contain microorganisms capable of degrading pollutants, but not every site has the specific microorganisms needed to complete the remediation process. This is particularly true for chlorinated solvents such as PCE, TCE, DCE, and vinyl chloride, where complete degradation often depends on specialized microbial populations.
Bioaugmentation supplements the native microbial community by introducing microorganisms with the biological capability to degrade specific contaminants. These introduced microorganisms work alongside naturally occurring microbes, but they still require favorable environmental conditions to become established and remain active. Providing food for microorganisms, maintaining appropriate groundwater chemistry, and creating anaerobic conditions are all essential for successful treatment.
Bioaugmentation should never be viewed as a stand-alone solution. It is one component of a comprehensive remediation strategy that must be tailored to the site’s geology, groundwater chemistry, contaminant distribution, and treatment objectives.
How Bioaugmentation Works
Bioaugmentation involves injecting specialized microbial cultures into contaminated groundwater or soil. Once introduced, these microorganisms become part of the existing microbial community and begin participating in the natural biological processes that degrade contaminants.
For chlorinated solvent remediation, bioaugmentation is commonly combined with electron donors that provide food for microorganisms. As microorganisms consume this food source, they establish and maintain the biological activity needed for processes such as reductive dechlorination. If dissolved oxygen is present, anaerobic conditions may first need to be established before the introduced microorganisms can perform effectively.
Successful bioaugmentation depends on much more than selecting a microbial culture. Proper amendment distribution, groundwater flow, contaminant concentrations, pH, oxidation-reduction potential (ORP), and site geology all influence whether the microorganisms can establish themselves throughout the treatment zone. The most successful projects create an environment where both native and introduced microorganisms can thrive.
Common Bioaugmentation Applications
Bioaugmentation is widely used during in situ remediation of groundwater contaminated with chlorinated solvents, particularly where site investigations indicate that native microbial populations are insufficient to completely degrade contaminants.
It is frequently incorporated into remediation programs involving PCE, TCE, DCE, vinyl chloride, and similar compounds. Bioaugmentation is often paired with electron donors and other biological remediation products to establish the conditions needed for long-term treatment.
Environmental professionals monitor groundwater chemistry, contaminant concentrations, dissolved oxygen, ORP, and other field parameters throughout the remediation process to evaluate treatment progress and confirm that favorable biological conditions are being maintained.
RNAS Technical Insight
A common misconception is that adding a bioaugmentation culture alone will solve a contamination problem. In reality, introduced microorganisms cannot perform effectively unless the surrounding environment supports their growth. They require food, appropriate groundwater chemistry, favorable redox conditions, and effective amendment distribution throughout the treatment zone. In many cases, creating the right biological environment is just as important as selecting the microbial culture itself.
How RNAS Supports This Process
Successful bioaugmentation combines specialized microorganisms with the products needed to support long-term biological activity.
- SDC-9 is a bioaugmentation culture containing specialized microorganisms used to enhance the biological degradation of chlorinated solvents when native microbial populations are insufficient.
- Newman Zone 55 and Newman Zone HRO provide long-term food for microorganisms, supporting sustained biological activity after the culture has been introduced.
- Newman Zone QR75 and Newman Zone QR90 provide soluble electron donors for applications where more rapid biological stimulation is desired.
- Newman Zone OS helps establish anaerobic conditions by removing dissolved oxygen that can interfere with the microorganisms responsible for reductive dechlorination.
- Neutral Zone helps maintain favorable pH conditions that support healthy microbial populations throughout the remediation process.
As with every in situ remediation project, successful bioaugmentation depends on matching the treatment strategy to site conditions and achieving effective amendment distribution throughout the contaminated treatment zone.
« Back to Glossary Index