Groundwater Sample Collection Methods

Science Center Objects

Collecting groundwater samples from a typical homeowner well...

illustration of setup of homeowner well

(Public domain.)

  • First, some Teflon tubing is connected to existing plumbing as close to the well as possible; in homes, this is often at a garden hose spigot at the pressure tank. Then, the well pump is run to remove standing water from the well casing. The excess water is drained outside, away from the well, or to a sink or sump. Sometimes, especially at private homeowner wells, a second faucet is opened to increase the water flow.
  • The tubing is connected to a meter that measures pH, temperature, specific conductance, and dissolved oxygen. After the standing water is removed from the well and the readings from the meter stabilize, they are recorded and the tubing is disconnected from the meter.
  • Next, the tubing is connected to a "sampling chamber" made out of a PVC frame and a plastic bag. The sampling chamber is used to prevent atmospheric contamination, for example, from vehicle exhaust when sampling outdoors. The sampling chamber allows sampling for some compounds at very low concentrations. The sampling chamber sits on a plastic container that is used as a portable sink.
  • About 20 different sample bottles are filled in the sampling chamber. Each bottle is used in a different analysis. Some bottles are filled directly from the tubing, others are filled with water that is filtered; some samples are preserved with acid; most samples are chilled.
  • After collecting the samples, the bacteriological sample is hand delivered to a local lab for processing; the rest of the samples are shipped overnight to other laboratories for analysis.
  • The location of the well is measured with a handheld global positioning system (GPS) unit for accurate mapping of the sample site.