Groundwater sampling equipment is used to collect representative groundwater samples from monitoring wells, deep wells and other groundwater investigation locations. A complete groundwater sampling setup may include sampling pumps, bladder pumps, well purging equipment, water-level measurement instruments and field water-quality monitoring equipment.
The right equipment depends on the monitoring well depth, well diameter, static water level, required sampling flow rate, target contaminants and sampling method.
For environmental monitoring projects, selecting the right groundwater sampling equipment is important because the equipment and sampling procedure can affect sample disturbance, VOC preservation, cross-contamination control and field efficiency.
What Is Groundwater Sampling Equipment?
Groundwater sampling equipment refers to the tools and systems used to access groundwater, purge monitoring wells, collect groundwater samples and evaluate water quality in the field.
A typical groundwater sampling system may include:
- Groundwater sampling pumps
- Groundwater bladder pumps
- Low-flow sampling equipment
- Well purging and well development pumps
- Groundwater samplers
- Water-level measurement instruments
- Multi-parameter water-quality meters
- Tubing, cables and sampling accessories
Different groundwater sampling equipment serves different purposes. A pump used for well purging, for example, may require a higher flow rate than equipment used for low-flow sample collection.
Main Types of Groundwater Sampling Equipment
1. Groundwater Sampling Pumps
A groundwater sampling pump transfers groundwater from a monitoring well to the surface while allowing the operator to control the pumping process.
The AML918 groundwater sampling pump is designed for groundwater sampling, well purging and well washing. Its published specifications include an adjustable sampling flow range of approximately 10–3000 mL/min and a higher flow range of approximately 0.1–12 L/min. AIMOLI reports a standard lift of 70 m and field use at approximately 300 m under specific application conditions.
For detailed product information, see the groundwater sampling pump.
2. Groundwater Bladder Pumps
A bladder pump is commonly used when controlled low-flow groundwater sampling is required.
The pump separates the drive air from the groundwater sample through a flexible bladder. This design can help reduce direct contact between the sample and drive air and is commonly considered for VOC and other sensitive groundwater sampling applications.
The AIMOLI AML919 groundwater bladder pump is designed for groundwater well purging and groundwater sampling, with particular emphasis on VOC collection and low-flow sampling.
See the groundwater bladder pump for product details.
3. Low-Flow Groundwater Sampling Equipment
Low-flow sampling is designed to reduce unnecessary disturbance to the formation and monitoring well while collecting groundwater at a controlled flow rate.
Low-flow groundwater sampling equipment is commonly considered for environmental monitoring projects where sample quality and controlled pumping conditions are important.
The equipment selection should consider the well construction, screen interval, water level, target contaminants and required stabilization criteria.
4. Well Purging Equipment
Well purging is performed before sample collection when the monitoring procedure requires removal of stagnant or non-representative water.
The required pumping rate depends on the well and the sampling method. High-flow pumping may be used for well development or purging, while controlled low-flow pumping may be preferred for sample collection.
Some groundwater sampling pumps can support both purging and sampling, reducing the amount of equipment required in the field.
5. Groundwater Monitoring Equipment
Groundwater sampling and groundwater monitoring are closely related but are not the same activity.
Sampling equipment collects groundwater for laboratory or field analysis. Monitoring equipment can measure parameters such as:
- pH
- Temperature
- Dissolved oxygen
- ORP
- Electrical conductivity
- Turbidity
A complete groundwater monitoring workflow may combine a sampling pump, water-level measurement equipment and a multi-parameter water-quality meter.
How Does Groundwater Sampling Equipment Work?
A basic groundwater sampling workflow normally includes several stages.
Step 1: Measure the Well
Before sampling, field personnel may record:
- Well depth
- Static water level
- Well diameter
- Screen interval
- Sampling depth
These measurements help determine the required equipment configuration.
Step 2: Purge or Develop the Well
Depending on the monitoring procedure, the well may need to be purged before sample collection.
The selected equipment must provide an appropriate pumping rate for the well and sampling method.
Step 3: Stabilize Sampling Conditions
For low-flow sampling, field parameters may be monitored during purging until the required stabilization criteria are reached.
Step 4: Collect the Groundwater Sample
The groundwater sample is collected using the selected pump or sampler.
For VOC sampling, controlling disturbance and unnecessary exposure to air is particularly important.
Step 5: Record Field Parameters
Field instruments can be used to record water-quality parameters during the sampling process.
How to Choose Groundwater Sampling Equipment
Before purchasing groundwater sampling equipment, consider the following factors.
Monitoring Well Depth
The equipment must have sufficient lifting capability for the required sampling depth.
Well Diameter
The pump or sampler must physically fit inside the monitoring well.
Static Water Level
Static water level affects the required pumping configuration and lifting requirements.
Required Flow Rate
Low-flow sampling and high-flow well purging have different flow requirements.
Target Contaminants
VOC sampling may require equipment and procedures designed to minimize sample disturbance and volatilization.
Sampling Method
Determine whether the project uses low-flow sampling, conventional sampling, discrete-depth sampling or another procedure.
Cross-Contamination Control
Cleaning procedures, tubing selection, equipment materials and field workflow should be considered when sampling multiple wells.
Groundwater Sampling Equipment for Deep Wells
Deep monitoring wells create additional equipment requirements.
The system must provide sufficient lifting capability while maintaining stable operation at the required sampling depth.
AIMOLI reports field applications of its groundwater sampling equipment in deep wells, including approximately 300 m applications for AML918 and configurations for deeper groundwater sampling using AML919.
Actual performance depends on well conditions, power supply, tubing configuration, groundwater characteristics and equipment configuration.
Groundwater Sampling Equipment for VOC Sampling
VOC sampling requires particular attention to sample disturbance and contact with air.
A bladder pump may be selected for applications where controlled low-flow sampling and reduced air contact are important considerations.
The AML919 groundwater bladder pump is specifically positioned by AIMOLI for groundwater VOC sampling and low-flow applications.
What Should a Complete Groundwater Sampling System Include?
Depending on the project, a groundwater sampling system may include:
- Well-depth and water-level measurement equipment
- Well purging equipment
- Groundwater sampling pump or bladder pump
- Sampling tubing
- Field water-quality instruments
- Sample containers
- Decontamination equipment
- Data recording and quality-control materials
Not every project requires every component. The final configuration should be based on the monitoring procedure and site conditions.
Conclusion
Groundwater sampling equipment is not a single type of instrument. It is a group of pumps, samplers, monitoring instruments and accessories used to collect and evaluate groundwater samples.
The most appropriate equipment depends on well depth, well diameter, flow requirements, target contaminants, sampling method and field conditions.
AIMOLI provides groundwater sampling pumps, bladder pumps and groundwater monitoring equipment for environmental monitoring and groundwater investigation applications.
For a complete overview of available systems, see AIMOLI’s groundwater sampling equipment page.
