A groundwater sampling pump is designed to move groundwater from a monitoring well to the surface for environmental sampling, well purging or groundwater investigation.
Unlike a conventional water pump, a groundwater sampling pump must be evaluated not only for pumping capacity but also for flow control, sampling depth, well conditions and potential effects on sample integrity.
For environmental monitoring projects, pump selection should match the well construction and sampling procedure.
What Is a Groundwater Sampling Pump?
A groundwater sampling pump is a pumping device designed specifically or adapted for collecting groundwater from monitoring wells.
Its main functions may include:
- Groundwater sample collection
- Monitoring well purging
- Well washing
- Well development
- Low-flow sampling
- Environmental site investigation
The required pump configuration depends on the project.
How Does a Groundwater Sampling Pump Work?
A typical submersible groundwater sampling pump is positioned inside the monitoring well below the groundwater level.
When powered, the pump moves groundwater through sampling tubing to the surface.
The operator controls the pumping conditions according to the sampling procedure.
For low-flow sampling, the goal is usually controlled pumping rather than maximum water output.
For well purging or well development, a higher flow rate may be required.
Groundwater Sampling Pump vs. Conventional Submersible Pump
A conventional submersible pump is mainly designed to move water.
A groundwater sampling pump must address additional requirements.
These can include:
- Stable flow control
- Sampling-depth positioning
- Monitoring-well compatibility
- Sampling tubing compatibility
- Reduced disturbance
- Field portability
- Cleaning and decontamination requirements
This is why a pump designed for general water transfer should not automatically be treated as groundwater sampling equipment.
What Is AML918?
The AIMOLI AML918 is a submersible groundwater sampling pump designed for groundwater sampling, well purging and well washing.
According to AIMOLI’s published product specifications, AML918 provides:
- Approximately 10–3000 mL/min sampling flow
- Approximately 0.1–12 L/min higher flow capability
- 70 m standard lift
- Adjustable flow
- Meter-marked composite cable
- Groundwater monitoring well applications
AIMOLI also reports field use at approximately 300 m under specific conditions.
See the AML918 groundwater sampling pump for detailed technical information.
When Should You Use a Groundwater Sampling Pump?
A groundwater sampling pump may be appropriate when the project requires:
Groundwater Monitoring Well Sampling
The pump can transfer groundwater from a monitoring well to the surface for field or laboratory analysis.
Well Purging
The pump can remove groundwater from the well before sampling when the sampling procedure requires purging.
Well Washing or Development
Higher flow may be required for well washing or development.
Low-Flow Sampling
A pump with stable flow control can be considered for controlled low-flow sampling applications.
How to Choose a Groundwater Sampling Pump
Consider the following factors before selecting a pump.
1. Required Sampling Depth
The pump must provide sufficient lifting capability for the actual well conditions.
2. Required Flow Rate
Determine whether the pump is needed for low-flow sampling, purging, well development or multiple applications.
3. Well Diameter
Confirm that the pump can physically fit into the monitoring well.
4. Groundwater Chemistry
Evaluate whether the pump materials are compatible with the groundwater and target contaminants.
5. Sampling Method
Low-flow, conventional and VOC sampling may require different equipment configurations.
6. Power Supply
Confirm the available power source and whether the system is suitable for field deployment.
7. Decontamination
Consider how the pump, tubing and other components will be cleaned between wells.
Groundwater Sampling Pump or Bladder Pump?
A groundwater sampling pump and bladder pump can both be used for groundwater sampling, but their operating principles are different.
A submersible groundwater sampling pump may provide a wider pumping range and can be useful when the same equipment needs to support well purging and sampling.
A bladder pump is commonly selected when controlled low-flow sampling and reduced air contact are important.
The correct choice depends on the sampling method, target contaminants and project requirements.
Groundwater Sampling Pumps for Deep Wells
Deep-well sampling places greater demands on the pumping system.
Before choosing a pump for a deep monitoring well, confirm:
- Actual water level
- Required sampling depth
- Required flow rate at depth
- Cable length
- Tubing length
- Power requirements
- Well diameter
A manufacturer’s stated maximum depth should not be treated as a universal performance guarantee.
Actual field performance depends on the complete system and well conditions.
Groundwater Sampling Pump Maintenance
Proper maintenance is important when equipment is used across multiple monitoring wells.
Field procedures should address:
- Pump cleaning
- Tubing replacement or cleaning
- Equipment inspection
- Cable inspection
- Decontamination
- Storage
- Post-project maintenance
For contaminated sites, the cleaning procedure should be designed according to the project’s quality-control requirements.
Conclusion
A groundwater sampling pump is more than a device for moving water. It is part of a sampling system that must match the monitoring well, flow requirements, sampling method and target contaminants.
The AML918 is one example of a groundwater sampling pump designed for both groundwater sampling and well purging applications.
For a complete overview of pumps, samplers and related equipment, visit the AIMOLI groundwater sampling equipment page.
