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UVOST System

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Dakota's UVOST® product efficiently delineates petroleum, oil, and lubricant (POL) contaminants in the subsurface. All the usual forms of POLs, including; gasoline, diesel fuel, jet fuel, and hydraulic fluids, can be detected via the fluorescence response of their polycyclic aromatic hydrocarbon (PAH) constituents. The fluorescence signal scales proportionally with NAPL concentration.
(UVOST struggles to detect high-PAH content NAPLs such as tars, bunkers, etc. - See TarGOST® for these "heavies")

UVOST's LIF technique, in conjunction with direct push deployment, yields a detailed three-dimensional map of the NAPL distribution, in real time - offering a true "seek and find" adaptive site characterization capability as promoted by U.S. EPA's TRIAD approach.

UVOST� is designed for rugged conditions

Major Benefits of UVOST®

  • Typical detection limit of 10-500 ppm (NAPL type and soil dependent)
  • Operates effectively above and below the saturated zone
  • Fast! – probe advances at ~0.8 inch/sec without pause
  • Typical daily productivity of 300-500 feet across 10-20 locations
  • One inch data density coupled with nearly instantaneous response provides continuous detailed log of product distribution and heterogeneity
  • Color-coded logs for the ultimate in qualitative information "at-a-glance"
  • Waveforms offer product identification/verification and rejection of non-contaminant fluorescence such as mineral, peat, and other minor interferents
  • Advanced UVOST® data analysis service from Dakota harvests waveform information to allow custom analyte isolation and/or interference rejection in the logs
  • CPT and percussion (Geoprobe/PowerProbe) deliverable – if direct push sampling gets there, UVOST® can get there


These frequently asked questions are meant for both our prospective UVOST customers and their clients. 

Is UVOST the same as MIP?

No. Technically the two are very different. In practice the MIP systems requires a greater amount of expertise on the part of the provider and has significantly higher expendable costs. Many of our UVOST service providers offer both technologies since they apply to disinctly different forms of contamination. Most technicians report that they prefer to operate UVOST over MIP since there are far fewer variables and less maintanence.


  • Designed specifically for NAPLs containing PAHs (source term)
  • Smooth/hard sapphire window is "slick" like Teflon - resists dragging NAPL down or smearing
  • Nearly instantaneous rise/fall - and 100% reversible response
  • UVOST does NOT "see" any useful levels of response to dissolved phase PAHs or VOCs
  • UVOST shows intimate detail of NAPL distribution (relative to MIP)
  • UVOST provides readily interpreted "spectral" information in real time
  • UVOST is blind to halogenated DNAPL - unless it was used to "degrease" PAHs


  • Specifically designed for VOCs
  • Encountering NAPL's "sticky" semi-VOCs often cause transfer line/carryover problems
  • Difficult to find "bottom" of NAPL due to carryover and resulting lag time
  • Logs require more experience and expertise to interpret (compared to LIF)
  • Less durable downhole components require more maintanence and replacement down time

Is there a UVOST in my region?
UVOST providers are generally willing to transport the system and work in any region. Operators will often sub-contract out or rent the delivery platform from a local direct push provider.

Where are UVOSTs being used?
UVOST systems are currently based out of the United States and Europe, with services being provided globally.

I am interested in purchasing a UVOST. How long will it take me to pay it off? (return on investment)
We believe it will take most service providers one year to pay for the UVOST. The UVOST has relatively low maintenance costs, is a great lead in for other services, and generates billable hours even after the UVOST site work is completed. While our UVOST providers travel far and wide to offer their services, many countries and most areas of the U.S. still do not have a local or even a regional provider, so the market potential remains strong and likely will for many more years.

Do I have the right staff to pull this off?
Almost certainly. If you purchase a UVOST we will train you on its use and the underlying science. We will always be available to answer any questions you or your client have. In general, if your employees are capable of following step-by-step procedures and are comfortable enough to turn on a computer, then they can operate a UVOST. That doesn't mean they can treat a UVOST like a hammer, but with care and reasonable effort they can produce world-class NAPL screening data day in and day out.

How hard is training?
Training is very thorough. We have put a lot of effort into our 3-day training program. While we give field operators a crash course on what UVOST can do and how it does it, we expect some will go over their heads. However, someone who has to interact on a daily basis with customers regarding what the UVOST system is reporting will have to have a deeper understanding of the underlying principles such as fluorescence. Likewise the day-to-day operation will be more important to those in the field. As always, we're here when you have questions.

Will Dakota forget about me after the sale?
Absolutely not. We pride ourselves on having great customer care long after the sale. Dakota knows what its like to be in the field. If one of our customers is having a problem, we consider it our top priority to get them back up and running ASAP. That's why many of our providers have purchased multiple systems!

What if I can't answer my client's questions about the data?
Dakota frequently gets calls from our UVOST provider's clients regarding data interpretation and we're happy to help. It's in our best interest if everyone is as educated about UVOST as possible, so we don't shy away from these calls. We're even available to consult on extensive data processing and interpretation projects, including 3D visualization for client's who don't have that capability in house.


Example Data

Certified Providers 

The following providers have undergone extensive training at Dakota and provide UVOST® service. Listing is alphabetical.

United States


UVOST® System Characteristics 

  • Power 110V AC 50-60 Hz (>=2kW generator)
  • Dimensions are 25" H x 24" W x 26" L cased
  • Weight ~120 lbs/54.5 kg cased instrument
  • Operating Temperature 32-100 °F
  • Storage Temperature 0-120 °F
  • Limit of Detection (LOD) 10-500 ppm (PAH NAPL on wet sand)
  • Excitation 308nm XeCl Laser (64Hz)

More Information

UVOST® Brochure (PDF Document)

LIF Introduction page provides a preliminary discussion of LIF technology

OST Software page provides an introduction to the software that controls the UVOST

Distributors of UVOST®

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