For every zone of your plume, we’ve got you covered!

Leaders in Remediation of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)

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- Enhances Efficiency

- Minimizes Methane Production

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Electron Donor

Solutions for


Reductive Dechlorination

Formulating Surfactant Blends

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Additive injection and groundwater recirculation trailers available for short or long term lease.

TersOx™ - Inorganic Peroxygen for Enhanced Aerobic Bioremediation

RemBind designed to treat TPH, PAH, PFOS, PCBs, PCPs, and various pesticides

Sulfate Enhanced Bioremediation 


Tersus is the worldwide distributor of the leading surfactant technology, TASK™ (Tersus Advanced Surface Kinetics) and related products, including the patented methods for in situ surfactant and chemical oxidation flushing (US Patent Nos. 6913419, 7021863, 7364386).  Our anionic surfactant formulations have the unique ability to selectively desorb and liberate sorbed petroleum hydrocarbons from soil and fractured bedrock surfaces allowing for their improved mass recovery and or improved treatment by other remediation techniques.

Supported by nearly two decades of research and formulation testing at the University of Oklahoma, TASK™ addresses a wide range of applications related to hydrocarbon contamination, including:

  • In situ soil and groundwater remediation
  • Pump and treat enhancement
  • Groundwater recirculation using EEF equipment
  • Direct Injection
  • Ex situ soil washing
  • Emergency spill clean-up
  • Equipment and tank cleaning
  • Sludge removal
  • Pipeline cleaning

The Basics

Non-aqueous phase liquids (NAPLs) are organic liquids, such as gasoline and diesel that are sparingly soluble in water. NAPL contamination commonly exists as blobs that become trapped within the formation. As they do not readily dissolve or mix with water, these compounds can remain as separate phase liquids for decades.

Because of the interfacial forces between NAPLs and groundwater, they are difficult to remove from the subsurface. NAPLs can be lighter than water (LNAPL), such as the aforementioned compounds, or denser than water (DNAPL), such as chlorinated ethenes. Surfactant Enhanced Aquifer Remediation involves the injection of specialty compounds with a molecular structure that has an affinity for the NAPL and groundwater. These compounds, called surfactants, can enhance the mobility and recovery of the trapped separate phase liquids. Surfactants can also facilitate the desorption of contaminant mass on matrix solids.

Surfactants are most appropriate for the removal of LNAPLs.  For example, if you get grease on your clothing, you do not attempt to clean them by just adding water. You also use a detergent. Soaps and detergents are examples of surfactants.

Please note that the removal of NAPL will enhance the effectiveness of bioremediation and chemical oxidation processes.

Choosing the Right Surfactant

The subsurface environment is notoriously difficult to remediate. Contact of the surfactant with the LNAPL and maintaining hydraulic control are exceedingly important. Also, choosing the right surfactant is critical. Factors to consider are the LNAPL itself, the groundwater chemistry and matrix mineralogy.

Currently, the conventional wisdom is to inject nonionic surfactants, as their chemistries will work in a wide variety of applications. Unfortunately, they easily adsorb to soil particles. Thus, when applying nonionic surfactants, you end up wasting a significant amount of money just dealing with the matrix demand. Furthermore, soils remove nonionic surfactants from water just like activated carbon removes organic contaminants from water. The manufacturers of nonionic surfactants typically recommend using 4 to 8% surfactant in the injectate.

Tersus’ approach is quite different, as we use anionic (negatively charged) surfactants. Our core expertise lies in the understanding of surfactant chemistry, which yields significant benefits to our customers; namely, you can reduce the amount of surfactants by almost an order of magnitude.


Our anionic biodegradable surfactants provide considerable advantages.

  • Dramatic reduction in cost
  • Minimal surfactant mass – usually 0.5 to  0.9 weight percent
  • 1 to 1.4 pore volumes for up to 95% mass removal
  • No creation of a stable-emulsion, which dramatically reduces treatment costs – the oil separates from the water in a holding tank in less than 30 minutes
  • Easy to handle waste stream
  • Any surfactants remaining in the subsurface are easily biodegradable

A key efficacy metric for surfactants is the reduction of the interfacial force, which is the force that keeps the oil trapped within pores. Most nonionic surfactants (conventional surfactants) reduce this trapping force by about an order of magnitude.

The Tersus approach is to use anionic surfactants, reducing the interfacial force by three to four orders of magnitude. Thus, you can save an enormous amount of money.



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Tech Brief
Mixing Instructions
SDS Español TASK™
Shipping Information
Xanthan Gum Spec Sheet

Guidance Documents

  • ITRC, Technical and Regulatory Guidance for Surfactant/Cosolvent Flushing of DNAPL Source Zones, April 2003 Download
  • Surfactant-Enhanced Aquifer Remediation (SEAR) Design Manual, NFESC, Technical Report,TR-2206-ENV, April 2002 Download
  • Surfactant-Enhanced Aquifer Remediation (SEAR) Implementation Manual, NFESC , Technical Report, TR-2219-ENV, April 2003 Download
Surfactant  Interfacial Force
(Oil and Water)
Injection Volume   Interfacial Force with Surfactant
Nonionic 30 to 50 mNewtons/meter 4 to 8% 5 mNewtons/meter
TASK™ (Anionic) 30 to 50 mNewtons/meter 0.5 to 0.9% 10-2 to 10-3 mNewtons/meter
Applying the correct anionic surfactant (e.g., TASK-GRO™ or TASK-DRO™) reduces the amount of surfactant required and improves the effectiveness of the remedy.


Tersus has formed a strategic alliance with Surbec Environmental.  Founded in 1997 at the University of Oklahoma, Surbec has nearly two decades of experience advancing the science of surfactant molecular design and NAPL recovery.  Surbec’s attention to the science of surfactant chemistry has made it the industry leader.

  • Tersus offers off-the-shelf surfactants for specific NAPLs, such as jet fuel, diesel and gasoline.
  • For larger, more complex problems, Surbec, in conjunction with the University of Oklahoma, optimizes the anionic surfactant formulation for the site specific geochemistry and NAPL.
  • By removing NAPLs, surfactants can enhance the effectiveness of bioremediation and chemical oxidation technologies.
  • Tersus can help design a surfactant flushing application that best fits your sites unique characteristics. Most applications can utilize existing site infrastructure, leading to a cost-effective treatment!  Engineering design services will be performed by the associated entity, Tersus Environmental of NC, PLLC.

Packaging Options

  • 55-gallon poly drums
  • IBC Totes
  • Bulk Tankers

Our Philosophy

Our team continues to develop and commercialize surfactant technologies that improve performance, lower costs and speed remediation.