Low Flow Sampling – how to choose the right equipment for the job

Low flow groundwater sampling is a best-practice method for collecting high-quality, representative water samples while minimising disturbance to the well and aquifer. Selecting the right equipment is crucial for reliable results and operational efficiency. HydroTerra offers a comprehensive range of low flow sampling solutions tailored to various site conditions and project needs.

Here’s how to choose the right equipment:

Understand Your Sampling Depth

First determine the depth from which you need to sample. HydroTerra’s equipment is categorized by depth capability:

Peristaltic Pumps: Ideal for shallow wells and surface water, effective up to 8 meters. The Solinst Model 410 Peristaltic Pump is a popular choice, offering variable flow rates and portability. It’s especially suitable for vapor sampling or when access is limited
Submersible Pumps: For intermediate depths, HydroTerra offers several options:
Whale Mega Purger: Up to 27 meters, simple to use with a WASP low flow controller.
Solinst 12V Submersible Pump: Up to 36 meters, lightweight and portable.
Proactive Stainless Steel Mega Monsoon XL: Up to 52 meters, robust and capable of very low flow rates.
Bladder and Double Valve Pumps: For deeper wells (up to 150 meters), these pumps are available in shallow (max 30m), medium (max 75m), and deep (max 150m) kits. Bladder pumps are preferred for VOC sampling due to no contact between drive gas and sample water, while double valve pumps offer higher flow rates and are better for silty or harsh environments.

Match Equipment to Water Quality and Regulatory Needs

Bladder Pumps are recommended for projects requiring strict regulatory compliance, especially for volatile organic compound (VOC) sampling. They ensure no cross-contamination from drive gases.

Double Valve Pumps are suitable for faster purging and environments with high sediment loads. They are low maintenance and have fewer parts to decontaminate.

Consider Power and Control Options

Power Source: Peristaltic and Submersible pumps operate on 12V DC batteries, with options for direct vehicle connection or portable battery holders. This is important for remote or inaccessible sites.
Controllers and Regulators: Electronic pump controllers and gas regulators (CO₂ for medium depths, N₂ for deep wells) are required for Bladder and Double Valve pumps and are included in kits to ensure precise flow control and prevent freezing at greater depths. Generally, you will need to source your compressed gas bottles locally if not located near our rentals office in Melbourne.

Kit Components and Field Usability

HydroTerra’s kits are designed for field efficiency and typically include:

• Pump and controller
• Compressor or regulator
• Tubing (LDPE or dual bonded)
• Tagline and carry case
• Quick-connect fittings for easy assembly

Seek Expert Advice

HydroTerra’s team can match equipment to your specific site and sampling objectives. Factors like well diameter, water chemistry, and regulatory requirements should all inform your choice.
Don’t hesitate to contact one of our specialists for tailored recommendations. Proper selection leads to more accurate data, regulatory compliance, and efficient fieldwork.

For more details visit HydroTerra’s website  Low-Flow Sampling Kits or contact the Sales team directly.  Contact Us