Ground Water Assessment Methods

Groundwater Assessment Methods

—♦Basic knowledge of geological and environmental conditions
—♦Review of previous investigation results
—♦Measurements of water levels
—♦Sampling & preliminary assessment of water quality

Water level measurements

—♦Periodic measurement
—♦standard tape measure (shallow wells)

♦‘dipmeter’: tape measure on reel with optional light & buzzer (deep wells and boreholes

Features

  • —Stretch resistant survey tape
  • —Tape marked in m, cm,mm
  • —Clear polyethylene coating on tape
  • —Corrosion resistance construction
  • —Sensitivity control test button
  • Visible and audible indicators

Operation

  • —In operation, the probe is lowered down the open bore until it comes into contact with the water surface. This completes the circuit and activates an alarm.
  • —The operator then reads the depth of the probe off the tape at the collar.
  • —The probe features a sensitive control to eliminate false water level readings due to dripping water.

Water quality measurements

—Periodic measurements

—♦sampling using appropriate bottles and methods:
—-bailer
—-sampling pump
—and testing on-site or later in laboratory.
—♦using portable instruments (e.g. salinity meter)