How to do VOC Sampling
Use a Waterra Pump system
Groundwater monitoring programs often sample for the presence of volatile organic compounds (VOC) in groundwater. This can be a complicated procedure because these compounds are, by definition, volatile. Through the sampling process, these compounds may escape from the water.
The challenge is to inexpensively collect samples without losing the VOCs.
Waterra has developed an effective and efficient means of collecting VOC samples using a Waterra Pump and a length of Waterra VOC Tubing. In effect, the VOC tube allows one to siphon off a sample from within the continuous vertical water column and direct the resulting laminar flow into a VOC sample vial.
This system has been used in countless groundwater sampling programs through the years and independent studies have shown validity of the data collected by these means.
To complement the Waterra Pump System you will need either HDPE or LDPE Waterra VOC Tubing. Note you may want to use a mechanical Waterra Tubing Actuator instead of the Lever Pump.
- Complete the applicable pre-sampling protocol whether it be the classic “purge three well volumes” or “pump until stability of well water parameters is achieved” or other protocol using a Waterra Pump system.
- Keep pumping but insert the VOC sampling tube up into the Waterra Tubing as illustrated above.
- Position the VOC tubing so that there is no cascading of water in the VOC tube.
- Direct the flow into your sample vessel.
Waterra Words of Wisdom
- You will need about 6 feet (2 m) of VOC Tubing per sample.
- Don’t reuse VOC tubing due to possible cross-contamination issues.
- Waterra VOC Tubing can be bought in long rolls and cut to length in the field
- A Waterra Tubing Cutter makes the job safe and easy
Waterra is aware that some groundwater investigators collect VOC samples using bailers. Premium quality EcoBailers are inexpensive and suffer no disadvantage relative to other bailers on the market.
Waterra Words of Wisdom
Waterra does not recommend VOC sampling with bailers due to the jostling and potential loss of VOCs during sample recovery to surface.
Waterra HDPE Nano / VOC Tubing$USD 10.35 – $USD 51.75
Waterra Hydrolift Pump – Tubing Actuator$USD 2,750.00
Waterra LDPE Nano / VOC Tubing$USD 10.35 – $USD 51.75
Waterra Pump Lever Arm – Tubing Actuator$USD 605.00