Module 5 — Monitoring and Maintenance of Your Water Well
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Water Well Sounder
A convenient method for measuring the water level is to use a water well sounder (also
called a water tape). You can purchase one from various suppliers in the province. Although
it is relatively expensive, it is a good investment. It’s an accurate and convenient way to take
water level measurements.
Sonic Sounder Method
The sonic well sounder is convenient because it does not need to be lowered down the well.
It is simple to use for most well constructions and only requires that the well cap be removed.
This instrument sends a pulse of sound down the well and records the time required for the
sound to echo back from the water surface, using time to calculate the distance to the water
level. It is non–invasive and easy to operate but may be more expensive and less accurate
than a well sounder.
Interpreting Water Levels
Once you have an accurate method for measuring water levels, you need to be able to
interpret two types of water levels — non-pumping (static) and pumping.
Non-pumping Water Levels
The non-pumping water level is recorded after the water level in the well has been
allowed to fully recover and before the pump is turned on. A good time to take a non-pumping
reading is first thing in the morning before there has been any water use.
After you have recorded several measurements over a period of time, you can determine
if the non-pumping water level in the well has changed significantly. Some change will
occur due to seasonal fluctuations. For example, in shallow wells, water levels are usually
highest in June or July and gradually decline in late September or October and throughout
the winter.
Water well sounders and sonic sounders
may be available for sale or rent from water
well drilling companies and water well
industry suppliers. Tape sounders should
be sanitized before and after each use.
Deep wells of 60-90m (200-300 ft) do not
experience seasonal fluctuations like
shallow wells.