The World’s Simplest Groundwater Sampling Pump

The Waterra Pump System (Inertial Pump) was developed in Canada in the 1980’s to meet demand for a reliable and inexpensive pump for purging and sampling groundwater monitoring wells.

The system is designed for everything from drive point size, 1/2 inch (1.2 cm) up to 2 inch (5 cm) and 4 inch (10 cm) wells or piezometers. It will also perform well in harsh environments that would ruin other more expensive pumps. Today, it has become one of the most prolific devices for purging, developing, sampling and VOC sampling monitoring wells.

Waterra Pumps are often dedicated to wells due to their low cost and to avoid cross-contamination or de-conning issues.

Here’s How A Waterra Pump Works

The Waterra Pump System is a simple, inexpensive way to sample a monitoring well. This is how it works.

  1. A Waterra Foot Valve is attached the bottom end of a length of Waterra Tubing.
  2. The Foot Valve – Tubing combo is inserted into the well, Foot Valve first, until the valve is submerged beneath the water table to the desired pumping depth.
  3. The tubing is then oscillated (pulled up and then pushed down) over a short vertical range of motion either by hand or with a Waterra Tubing Actuator.
  4. Water builds up in the oscillating tubing until it discharges at surface.

Waterra Pump System is available in four performance ranges:


Micro Flow

up to ½ gpm & max 75 feet – drive points – (< 1.9 lpm & 23 m)


Low Flow

½ gpm & max 100 feet – piezometer sampling – (1.9 lpm & 30 m)


Standard Flow

1 gpm & max 200 feet – our most popular system – (3.8 lpm & 60 m)


High Flow

up to 4 gpm & max 300 feet – deep well sampling – (15 lpm & 90 m)

Foot Valves

The High Flow Foot Valve System is designed to be used in 2 inch wells or larger where a high pumping rate is desired or where very deep wells are encountered. This system is also an excellent well development tool in 2 inch piezometers.

Inertial Pump Actuators

The Waterra Pump Systems provides the mechanical actuation for pumping with inertial pumps to depths of over 60m, in a fully portable, single operator power unit. At 13 kg, the PowerPack PP1 provides outstanding pumping performance.


High Density Polyethylene also provides a stronger valve-tubing connection, especially with the male threaded valves, because it is stiffer and gives less when the valve is threaded into the tubing.