Enhanced Bioremediation


Enhanced bioremediation uses indigenous or inoculated (i.e., introduced) micro-organisms (e.g., fungi, bacteria, and other microbes) to degrade or metabolize organic contaminants found in soil and groundwater.

The micro-organisms use the organic contaminants as a food source, thereby breaking them down and converting them into less toxic compounds and harmless by-products, such as carbon dioxide and salt water. Nutrients, oxygen, or other amendments (e.g., vitamin B-12, emulsified oils, surfactants) may be used to enhance bioremediation and contaminant desorption from subsurface materials, since bioremediation takes place in the aqueous phase.

Most contaminants are amenable to bioremediation to some extent, however, in some cases the contaminants are present at such high concentrations that they are toxic to the micro-organisms. In these situations other remediation approaches, such as chemical oxidation, must be employed first to reduce contaminant concentrations before bioremediation can take place as a finishing or “polishing” stage.


In the presence of sufficient oxygen (aerobic conditions), and other nutrients, microorganisms will ultimately convert many organic contaminants to carbon dioxide, water, and microbial cell mass. This approach is effective for:

  • BTEX compounds
  • Petroleum hydrocarbons (gas, diesel, etc.)
  • MTBE


Anaerobic processes are conducted in the absence of oxygen, and the end products can include methane, hydrogen gas, sulfide, elemental sulfur, and dinitrogen gas. This approach is effective for:

  • Chlorinated ethenes (PCE, TCE, DCE, VC, etc.)
  • Chlorinated ethanes (TCA, DCA, etc.)
  • Carbon tetrachloride
  • Chlorinated methanes (TCM, DCM)


Vertex has successfully designed, implemented and optimized dozens of in-situ enhanced bioremediation programs in a variety of geologic environments. Electron donors and/or acceptors Vertex staff has utilized include:

  • Oxygen-releasing compounds and devices
  • Hydrogen-releasing compounds and devices
  • Wood chips and leaf compost
  • Organic carbon including molasses, acetate, lactate, vegetable oil, etc.
  • Edible oils
  • Acetate and lactate
  • Polymers

Vertex combines strong theoretical understanding with practical experience to properly plan and implement the right remedial program for your site. Selecting Vertex to undertake your remediation project allows you to access a wealth of in‑situ remediation knowledge and experience.

Related Vertex Projects