Bioremediation: a glossary of commonly used terms
Posted June 18, 2020

The bioremediation industry is full of terms that you probably don’t use regularly—and perhaps some that you’ve never heard before! We’re going to break some of them down for you:


Benzene is a volatile organic compound (VOC) typically found at sites where petroleum hydrocarbons have adversely impacted soils and/or groundwater. Benzene is found in crude oils and as a byproduct of the oil-refining process. In industry, benzene is used to make rubbers, lubricants, dyes, detergents, drugs, and pesticides, as well as some other chemicals. Benzene is typically found with its associated regulated compounds Toluene, Ethylbenzene and Xylenes, forming the BTEX group. Benzene is a frequent contaminant of soils and groundwater and is a common target of biostimulation/bioremediation remediation efforts.


Biofilms were first recorded by Antonie van Leuvenhoek in the late 17th century and have since been found to constitute the predominant mode of growth of bacteria in streams and lakes in virtually all parts of the world, in teeth as plaque and common infections. Biofilm consists of exopolysaccharide materials with ephemeral structures housing one or more types of microorganisms that, once afforded appropriate conditions, begin to work collectively as a consortium of microbial populations in harmony for the collective good. Bacteria and fungi are both examples of microorganisms that form biofilm which serve as energy and nutrient ‘sinks’, capable of expediting residual mass solubilization and the long-term, sustainable assimilation/transformation of dissolved-phase contaminants. TerraStryke products are designed to eliminate the environmental stresses to microbial growth, enhance biofilm development and aid Mother Nature at doing what she does best, utilize energy; or as we refer to it, site contaminants sustainably, effectively, completely.


Biostimulation is one method of bioremediation; and is becoming a leading method to achieve successful bioremediation of contaminated sites by enhancing indigenous microbial populations and the ecosystem in which they exist. The process includes the addition of components that represent rate limiting factors to microbial development/growth; these may include nutrients, electron acceptors and/or donors. TerraStryke products are specifically designed to provide rate limiting components to boost the growth, development, communication, and collective performance of indigenous microorganisms to achieve long-term Site compliance.

Brownfield redevelopment sites

Brownfield sites are typically urban industrial properties where past use has left site structures, soils and/or groundwater contaminated with regulated building materials, inorganic and/or organic compounds. Typically, these sites are not currently in use due to the adverse site conditions which also limit future redevelopment opportunities. Examples include sites of former factories, manufacturers, dry cleaners and service/gas stations. TerraStryke products are designed to enhance site redevelopment without above ground equipment, fuel use and costs and nuisance noise and/or emissions making each TerraStryke biostimulation additive ideal for use at Brownfield sites. By enhancing nature’s way to utilize subsurface contaminants (energy) we facilitate remediation concurrent with redevelopment, saving time, permitting, and costs.

Chlorinated solvents

Chlorinated solvents are one of a family of chemical compounds know as organic-halides. Chlorinated solvents or, chlorinated volatile organic compounds (cVOCs), contain carbon and chlorine atoms. In biostimulation, we enhance the ability of indigenous dehalorespiring bacteria to utilize the electron on the chlorine atom for respiration. Chlorinated solvents are found in manufacturing degreasers, pesticides, glues, typical cleaning solutions and other mixing and thinning solutions. Chlorinated solvents are heavier than water and as such are called ‘sinkers’ which either solubilize into the groundwater or remain as non-solubilized residual mass or DNAPL. Chlorinated solvents are some of the most common environmental contaminants encountered in bioremediation requiring decades to remediate. TerraStryke product ERDenhanced nourishes the subsurface ecosystem and indigenous microbial populations to achieve 3+ orders-of-magnitude destruction in months, not years saving time, money while facilitating safe redevelopment.

Greenhouse gases

Greenhouse gases are those that trap heat in the atmosphere. Two of the most commonly known greenhouse gases are carbon dioxide, which is the result of burning fossil fuels (like oil and natural gas) and methane, which often comes from livestock and agriculture practices. TerraStryke biostimulation additives not only expedite residual mass solubilization, smear zone destruction, dissolved-phase utilization and long-term site compliance; our remedial strategies actually sequester greenhouse gas emissions within the treatment zone to further minimize your sites’ carbon footprint, providing a Green solution to your current environmental liabilities.

Petroleum hydrocarbons (PHCs)

Petroleum hydrocarbons refers to a range of chemicals found in crude oil and numerous biproducts including, gasoline, diesel, lubricating and heating oils. Due to their frequent use throughout industry and society, soils and groundwater are commonly adversely impacted by PHC contaminants. Biostimulation is a very practical and effective way to remediate petroleum hydrocarbons safely and sustainably. TerraStryke additives effectively get the rebound out up front, destroying smear zone contaminants to ensure long-term site compliance. For proper treatment, total PHCs need to be recorded at any site, even if only BTEX, Naphthalene, Jet Fuels, and/or other gasoline related constituents are the site remediation driver.

Smear zone

Smear zones consist of saturated soils at the soil groundwater interface where, due to fluctuations in groundwater elevations, contaminant mass has adsorbed or ‘smeared’ across the vertical soil column. TerraStryke biostimulation additives are ideal for smear contaminant destruction. Our process enhances the indigenous microbial populations to solubilize, organically by secreting surfactant-like products, adsorbed smear zone contaminants to effectively turning contaminant mass, not available for microbial utilization, into dissolved-phase bioavailable contaminants. By getting the rebound ‘out-up-front’ our biostimulation processes help realize long-term site compliance faster and sustainably saving time, costs, and enhancing redevelopment of adversely undeveloped properties.

Tetrachloroethylene (PCE)

Tetrachloroethylene is a chlorinated solvent commonly used for drycleaning, metal cleaning, and in textile processing industries. Dehalorespiring bacteria utilize the electron on the Chloride atom to facilitate respiration. Complete respiration of all electrons on the PCE molecule is referred to a ‘complete biostransformation’. When PCE (the parent cVOC) is completely utilized the end product is Ethene, with various steps in between which result in the generation, and subsequent biotransformation, of the daughter cVOCs Trichloroethylene (TCE), Dichloroethylene (DCE) and Vinyl-chloride (VC). TerraStryke products enhance the subsurface ecology of the treatment zone to maximize the ability of indigenous bacteria to completely biotransform (utilize) cVOC contaminants sustainably, realizing mass destruction in months, not years with little to no adverse impacts. Additionally, our biostimulant ERDenhanced will generate and maintain reducing conditions for 10-20 years after a single injection event; saving time and costs.

Underground storage tanks (USTs)

Underground storage tanks are used to store regulated substances, often petroleum, beneath Site structures. The USTs are manifolded to delivery systems which transfer from the subsurface, fuel to the surface for use. Often, delivery systems, the act of delivery and/or the UST themselves leak causing adverse impacts to the soil and groundwater. Leaking is a serious potential hazard with underground storage tanks, and TerraStryke biostimulation products are ideal to address contamination of numerous varieties of regulated tank contents sustainably, effectively, and completely.

Volatile organic compounds (VOCs)

Volatile organic compounds are compounds that easily turn into vapors or gases. Many commonly used consumer products release VOCs, including cigarettes, paint, glue and adhesives, air fresheners, and wood preservatives. Typical VOCs include BTEX components, formaldehyde, and semi-volatile organic compounds (sVOCs) include pesticides and plasticizers. TerraStryke biostimulation products are ideal to address VOC/sVOC contaminants in soils and/or groundwater by enhancing natures ability and indigenous microbial populations to utilize these compounds as electron donors andsubsequently assimilate (eat) them rendering the site compliant safely, sustainably and cost effectively without any above ground support equipment.

Want to learn more?

If you want to learn more about what’s involved in biostimulation, please visit our overview page or read our case studies or simply call at anytime to discuss how TerraStryke can assist you.