Well maintenance is not complicated and it is easy to let slide, because a well that is working gives no reason to look at it. The tasks that matter are few, and most of them are inspections rather than work. The EPA notes that private wells are not federally regulated under the Safe Drinking Water Act, so this list is nobody's responsibility but the owner's.
Every year
Test for coliform bacteria and nitrate at minimum, and add pH, hardness, iron and manganese every few years or whenever something changes. Walk the wellhead: casing standing well above grade, ground sloping away from it, cap intact and vermin proof, sanitary seal sound, and no evidence of surface water reaching the annulus. Check the pressure tank's air charge, since a waterlogged tank short cycles the pump and shortens its life considerably. Replace any UV lamp on its annual schedule.
Every season, and by observation
Note the pressure at a tap and whether it has changed, since a gradual fall points at a failing pump, a blinding filter or scale. Listen for the pump cycling more often than it used to. Look at the water in a clear glass now and then for new cloudiness, color or grit. Check filter housings for weeping and replace cartridges on their schedule rather than on appearance. Clear vegetation and stored chemicals away from the wellhead, and never park or store fuel near it.
After specific events
Test after any flooding that reached or approached the wellhead, after any work on the well, the pump or the plumbing, after a neighbouring well is drilled or an old one abandoned nearby, and after any change in land use above the aquifer such as livestock arriving. Also test whenever the water changes in taste, smell or appearance, and whenever anyone in the household has recurring stomach upsets with no other explanation. Those are the moments a routine annual test will miss.
Every few years
Have the well itself inspected by a contractor, covering yield, water level, pump performance and casing condition, because a well degrades gradually and the early signs are not visible from the surface. Sanitize the well and plumbing if bacteriological results have been marginal. Inspect and clean the pressure tank. And keep records: test results, work done and dates, because the trend across years tells you far more than any single result. Our well filtration guide covers treatment design.
Questions people ask about water well maintenance checklist
How often should a private well be tested?
Annually for coliform bacteria and nitrate at minimum, with pH, hardness, iron and manganese every few years or when things change.
What should I look at on the wellhead?
Casing well above grade, ground sloping away, an intact vermin proof cap and sanitary seal, and no surface water reaching the annulus.
When should I test outside the annual schedule?
After flooding, work on the well or plumbing, a neighbouring well being drilled, land use changes, or any change in taste or appearance.
Does the well itself need inspecting?
Every few years, covering yield, water level, pump performance and casing condition, since degradation is not visible from the surface.