The Membrane Interface Probe (MIP) and the Hydraulic Profiling Tool (HPT) are both powerful site investigation tools in their own right. With the recent introduction of the MiHPT system you can now double your production rate as these two systems become one.
Numac has just commenced operation of the new system and clients are immediately impressed with the ease you can now correlate the VOC and Hydraulic inputs.

The new probe detects volatile contaminants with the MIP, measures soil electrical conductivity with a standard (MIP) dipole array, and measures HPT injection pressure using the same down-hole transducer as the Geoprobe® stand-alone HPT system.  In post-processing the log data  the user is able to estimate hydraulic conductivity (K) and water table elevation, as well as prepare graphical outputs of the log data.

The probe is robust and percussion driveable (hammerable) with Geoprobe direct push machines. Daily production rates are well in excess of standard sampling techniques ensuring that site assessments are completed in shorter time frames than conventional drilling surveys. 

The high density data makes it ideal for use with modeling software and facilitates the quick and accurate development of conceptual site model in 2D and 3D. 


With environmental site assessments(whether at an industrial facility, a retail petrol station, or a landfill),  in order to conduct an effective site characterization and then move forward with remediation design plans, one must have a comprehensive knowledge of their sites’ vertical profile.

MIP Features and Applications

There are many features with the MIP technology, such as:

  • Fast, continuous, real-time profiling of soil subsurface
  • Effective on volatile organic compounds (VOCs) such as halogenated solvents (PCE, TCE) and petroleum (BTEX) compounds. 
  • Real time data output to all stakeholder
  • Use in both saturated and unsaturated conditions
  • Built to hammer with standard Geoprobe machines
  • Provides a simultaneous log of conductivity with integrated Di-Pole array
  • Parameters are displayed and stored on the laptop computer for future analysis
  • Data can be incorporated into 2-D/3-D visualizations in real time for quick decision-making in the field

MIP technology can be used at virtually any site, under any condition (indoor, outdoor, difficult access), such As:

  • Dry cleaners
  • Brownfields Sites
  • Petrol/fuel retail stations and petroleum depots
  • Manufacturing facilities, warehouses, and other industrial sites
  • Railroads
  • Defence sites
  • Landfills
  • Environmental pre- and post-remediation assessments

Data is collected in real time at a rate of 65 readings per meter with no vertical data gaps to accurately identify zones of contamination and pinpoint natural and man-made preferential pathways in the subsurface.  Data is then incorporated into 2-D and 3-D graphics for real-time visualization of subsurface contaminant plumes.


 MIP GC 2000

MIP GC 2000

As a continuous VOC sampling system which heats the soil, water, and vapour matrix as it is driven into the subsurface, the MIP maps contaminants within the groundwater and the surrounding soil. The VOC mass which is extracted across a semi-permeable membrane is carried to the surface by an inert purge gas via small diameter inert tubing. Once the compounds reach the surface they are analysed by a suite of three laboratory grade detectors.

The sensor detection system includes:

  • Photo Ionization Detector (PID)
  • Flame Ionization Detector (FID)
  • Halogen Specific Detector (XSD)

Together, these three detectors offer a range of sensitivities and a means of discriminating different classes of compounds - anything from chlorinated solvents to gasoline hydrocarbons to methane soil gas. The use of multiple detectors is important for separating different types of contamination such as petroleum (retail gasoline station) from chlorinated solvents (dry cleaners). The complementary range of performance of the different detectors enables the system to function from low contaminant levels to near NAPL levels.

The inclusion of the  Electrical Conductivity (EC) probe to provide indication of general soil particle size which can help determine zones of sands, silts, and clays. Using the EC logs you can define zones of lower conductivity which allows the movement of contaminants into the subsurface.