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Module 7 — Troubleshooting Water Well Problems
Symptom #1 — Reduced Well Yield
Possible causes:
What to check for:
How to correct:
Pump and/or water system
Low pump production in spite of normal
water level in well. Leak in system; worn
pump impeller.
Have a licensed water well contractor or
plumber check the pump and water system.
Biofilm build-up in well casing, well screen or
pump intake.
Slime build-up on household plumbing fixtures
and livestock waterers. Inspect pump and use
down-hole camera to check for slime build-up.
Shock chlorinate the well and water system
as required - usually once or twice a year. See
Module 6 "Shock Chlorination".
Mineral scale (incrustation) build-up on
perforated well casing, well or pump screen.
Scale formation on plumbing fixtures and
livestock waterers. Inspect pump. Use down-
hole video camera to check for mineral build-
up. Calculate the Ryznar Stability Index
to determine the water's incrustinq potential.
Once the type of mineral scale has been
identified, the well should be cleaned by a
licensed water well treatment specialist.
Treatment could include both physical
aqitation and chemical/acid treatment.
Sediment plugging on outside of perforated
casing or screen.
Sediment in water, followed by a sudden
decline in yield.
Have a licensed water well contractor
redevelop the well.
Collapse of well casing or borehole due to age
of well.
Sediment in water. Compare current depth of
well with original records. A collapsed well will
show a shallower depth than the original well.
Recondition the well. If repair is not
economical, plug the well and redrill. •
See Module 9 "Plugging Abandoned Wells”.
Neighbouring well interference.
Check for significant drop in water levels in
nearby wells. Contact Alberta Environment
and Sustainable Development to determine if
groundwater use in the area has increased.
Identify other nearby wells located in the same
aquifer. Reduce pumping rates as required.
Aquifer depletion
-
rate of withdrawal exceeds rate of recharge
-
periods of drought can temporarily deplete
shallow groundwater zones
Compare current non-pumping static water
level with the level at the time of well
construction. A lower level confirms aquifer
depletion. Contact Alberta Environment and
Sustainable Development to see if water levels
are declininq.
Reduce the water use. Install additional
storage to meet peak water requirements.
Drill a deeper well or one that taps into
another aquifer.