Water for a private house usually comes from a dug well or a borehole. Both work, but they suit different needs: a well is simpler and cheaper, while a borehole gives more water and is more often of better quality. Decide before you buy the pump and pipes.

What the diagram shows

1 — a well made of concrete rings, 2 — water in the well from the upper aquifer, 3 — the borehole screen in a deep aquifer, 4 — the borehole casing with a submersible pump.

Dug well

  • Depth is usually up to 10–15 m: a well draws from the first aquifer.
  • The water is close to the surface, so run-off, fertiliser and rainwater reach it more easily. Testing well water is especially important.
  • Quantity. The supply is limited to what stands in the rings and what flows in. The level often drops in summer.
  • The pump is a surface booster set or a submersible well pump.
  • Pros: cheaper, can be dug by hand, and you can still draw water with a bucket during a power cut.

Borehole

  • Depth ranges from 15–20 m into sand to a hundred metres or more into limestone.
  • The water is better protected from surface contamination but often contains iron, manganese or hardness salts — you will need a filter chosen from a water test.
  • Quantity. The yield is usually higher than a well’s and depends less on the season.
  • The pump is a submersible borehole pump sized for the depth and yield.
  • Cons: more expensive, needs a drilling rig, and without electricity you cannot raise the water.

How to choose

  1. Ask the neighbours how deep their water is, what it is like and whether their wells run dry in summer. It is the most reliable information about your plot.
  2. For a summer cottage with garden watering, a well or a shallow sand borehole is often enough.
  3. For a house lived in all year, with a water heater, washing machine and several bathrooms, a borehole is more reliable.
  4. Either way, test the water and choose the treatment — see “How to choose a water filter”.
A well or borehole must be well away from a cesspit, septic tank and places where animals are kept. Sanitary rules set the distances, so check them before work starts.

For a borehole pump, see “How to choose a borehole pump”; for a well, see “A booster pump set for a private house”. Pumps and controls are in pumps.