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Module 7 — Troubleshooting Water Well Problems
Symptom #3 — Change in Water Quality
Possible causes:
What to check for:
How to correct:
Corrosion of well casing, liner or screen,
causing holes. Holes can allow water of
undesirable quality to enter the well.
Change in water quality, may be coupled with
sudden appearance of sediment in water.
Calculate the Ryznar Stability Index to
determine the water's corrosion potential.
Consult a licensed water well contractor.
Depending on the well construction, repair
or replace well using alternate construction
materials. Plug old well. See Module 9
“
Plugging Abandoned Wells”.
Failure of the annulus or casing seal.
Sudden appearance of sediment, coupled
with a change in water quality. Test water
quality regularly and investigate when quality
changes occur.
Consult a licensed water well contractor.
It may be possible to re-establish the seal.
If repair is not economical, plug the well and
redrill. See Module 9 "Plugging Abandoned
Wells".
Iron-related bacteria or sulfate-reducing
bacteria (biofouling).
Change in water quality such as colour,
odour (e.g., rotten egg) or taste. Check inside
of toilet tank for slime build-up and inspect
pump.
Shock chlorinate the well. For more
information on shock chlorination, see
Module 6 "Shock Chlorination".
Contamination sources.
Changes in water quality such as colour, odour
or taste. Compare results from regular water
analyses for changes.*
Identify and remove contamination source.
Continue to monitor water quality through
regular water testing.
*
In many cases, variations in water quality will not result in observable changes in odour, taste or colour. For
instance, in situations where nitrate levels are increasing, there may be no apparent change in the odour,
taste or colour of the water.