Membrane Interface Probe (MIP)

Diagram of Membrane Interface Probe

MIP probe diagram

The Membrane Interface Probe (MIP), is one of the High Resolution Vertical Profiling tools which COLUMBIA Technologies offers to detect subsurface contamination for environmental site assessments and characterizations. MIP is a multipurpose tool for mapping soil and groundwater contamination, specifically volatile organic compounds (VOCs) such as halogenated solvents and petroleum compounds.

Where can I apply MIP for my environmental site assessments?

  • Dry cleaners
  • Gasoline/fuel retail stations and petroleum terminals
  • Manufacturing facilities, warehouses, and other industrial sites
  • Railroads
  • Military installations
  • Brownfields, Superfunds, and other cleanup sites
  • Landfills
  • Environmental pre- and post-remediation assessments
To discuss how MIP can be applied for your site investigation, click on the contact button below or call us at +1-888-344-2704.

What compounds can MIP detect for my environmental site assessments?

Dissolved phase and Non-Aqueous Phase Liquid (NAPL), including:

  • Halogenated solvents
    • Tetrachloroethylene (PCE, also referred to as Perc)
    • Trichloroethylene (TCE)
    • DCE
  • Other non-halogenated solvents
  • Petroleum compounds
    • Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX)

Please contact us to find out if the MIP can detect other compounds for your specific environmental site assessment.

 

How can MIP be applied at my specific site?

The Membrane Interface Probe with Electrical Conductivity (MIP/EC) is used for field screening to rapidly map dissolved phase petroleum and chlorinated solvent contamination. The MIP/EC will quickly delineate both the horizontal and vertical extent of dissolved phase contamination and identify areas of highest concentration. The MIP/EC can be used in saturated or unsaturated zones.

MIP is a continuous volatile organic compound (VOC) sampling system that heats the soil, water, and vapor matrix as it is driven into the subsurface. The VOC mass which is extracted across a permeable membrane is carried to the surface by an inert purge gas via small diameter inert tubing. At the surface, the VOC mass is passed across a chemical detector suite to provide a correlation between contaminant detection and the depth of the probe at the point of detection. COLUMBIA’s standard MIP sensor detection system utilizes three laboratory grade detectors in its sensor detection system:

  • Photo Ionization Detector (PID)
  • Flame Ionization Detector (FID)
  • Electron Capture Detector (ECD)

Example MIP Log

COLUMBIA can configure the MIP system with a Halogen Specific Detector (XSD) depending on the project objectives, contaminants of concern, and contaminant concentration levels. Just like in the laboratory each detector has a different sensitivity and linear range for various chemical compounds. In general, the PID and FID provide excellent response to VOCs such as benzene, toulene, ethylbenzene, and xylenes (BTEX) compounds typically found in petroleum product, such as gasoline and diesel fuel. The ECD detector is highly sensitive to chlorinated or halogenated compounds, and is much more sensitive than the XSD for certain compounds such as tetrachloroethylene/trichloroethylene (PCE/TCE). However, the ECD also has a limited linear range and can saturate at lower concentrations (for PCE/TCE). The XSD detector will see a larger range of halogenated compounds and is a better responder for degradation products than the ECD. Many common chlorinated compounds will also respond on the PID depending on the compound ionization potential.

Use of multiple detectors is important for separating different zones of contamination such as petroleum (retail gas station) from chlorinated (dry cleaner). The complementary range of performance of the different detectors enables the system to function from low contaminant levels to near NAPL levels.

The MIP probe has an integrated Electrical Conductivity (EC) array 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.

Modular approach configured MIP system on a pickup truck at an industrial site

The MIP can be used on site with a Hydraulic Profiling Tool (HPT) probe which enables project decision makers to understand the details of soil permeability leading to contaminant mobility and migration. Deploying both MIP and HPT during the same investigation would provide multiple lines of evidence with only one mobilization. MIP and HPT technologies are deployed on two separate tooling strings, unless a combined Membrane Interface Probe-Hydraulic Profiling Tool (MiHpt) is pushed. Combining HPT information with MIP information enables project decision makers to more cost effectively select sampling locations early eliminating the costly delays associated with the traditional investigation tools and approaches. The permeability information is also critical to selecting remedial alternatives and properly placing injection and extraction intervals.

COLUMBIA's direct sensing vehicle during a cold weather MIP investigation at a site in the Midwest

COLUMBIA offers a cold weather MIP system with a heated trunkline option for MIP investigations ideal for colder climates. The heated trunkline prevents water vapor in the trunkline so that you won’t have freezing or blockages from frozen water in the trunkline. In addition to application for colder climates, the heated trunkline option is recommended for higher contaminated zones, as it allows for higher contaminant levels to efficiently move through the trunkline preventing contaminant carry-over. The heated trunkline option provides quicker cleanup times resulting in less downtime and better contaminant bottom definition, quicker contaminant response and cleanup.

Since our sensors can be deployed from any type of Geoprobe (ranging from all-terrain track rigs to confined-space dolly mounts) we can increase your reach in locations that would typically be difficult to access.

Go from the Membrane Interface Probe (MIP) page to our High Resolution Vertical Profiling services page.

Do you want to further discuss the possibilities of using MIP at your site? Complete the form below and we’ll contact you to discuss your project.