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Groundwater
Profilers
GWP and HPT-GWS

How sampling works
A pump actuator mounted on top of the 1.75 in. rods of a Groundwater Profiler, with the sample tubing running out of it
Groundwater Profiler1.75 in. rods
A pump actuator mounted on top of the 2.25 in. rods of an HPT Groundwater Sampler, beside the orange HPT trunkline
HPT Groundwater Sampler2.25 in. rods

When to use groundwater profilers

  • Vertical contaminant plume profiling
  • Regulatory compliance sampling at specific depth intervals
  • Dissolved-phase concentration verification after high-resolution site characterization (HRSC) screening
  • PFAS and emerging contaminant investigations
  • Risk assessment data collection
  • Post-remediation confirmation sampling
  • Hydrogeologic characterization with targeted chemistry
  • Sites requiring both screening data and lab-confirmed concentrations

See the tool comparison if your objective is not here.

About HRSC

How sampling works

  • Sand
    High permeability
  • Clay
    Low permeability
  • Injection line
  • Sample line
  • Water out through
    the screens
  • Groundwater in
    through the screens
  • Screens
  • HPT-GWS
A drawing of the HPT-GWS tool on the end of the rods, not to scale, with the rod cut open to show two separate tubes fitted to the top of the tool: the injection line and the sample line. It plays the steps of one sampling depth in a loop. The tool is pushed down through clay into sand as water runs down the injection line and out through the screens. It stops, and the water stops. Groundwater then comes in through the same screens and up the sample line. Last, water runs down the injection line again and flushes the sample line, and the tool moves on to the next bed of sand.

At each sampling depth

Samples can be analyzed for any dissolved-phase analyte: VOCs, SVOCs, metals, 1,4-dioxane, PFAS, and more.

Compare the two profilers

Choose a groundwater profiler
1.75-inch Groundwater Profiler

Groundwater Profiler

Sensors
  • Discrete Interval Sampling
  • HPT Pressure (uphole)
Advantage
Its 1.75 in. rods can often be driven deeper than the HPT-GWS.
Disadvantage
No electrical conductivity (EC) and no downhole pressure transducer.

When to pair it with HPT

In thick permeable soils, the GWP’s HPT pressure, measured at the surface, is enough to pick sampling intervals. Where permeable zones are narrow, find them first with HPT.

HPT Groundwater Sampler

HPT Groundwater Sampler

Sensors
  • Discrete Interval Sampling
  • HPT Pressure
  • Electrical Conductivity
Advantage
Logs electrical conductivity (EC) and downhole HPT pressure in the same push that collects the samples.
Disadvantage
At 2.25 in., it often cannot be driven as deep as the GWP.

Contact us to add discrete sampling to your investigation program.

Talk to an expert