How to protect your water supply from contamination

Make sure you regularly check your supply, including the catchment area. You should correct any damage and defects as soon as possible.

Supplies from springs, wells or boreholes

Check that adequate protection is provided to stop surface water getting into your supply.


Supplies from streams, rivers, lakes or ponds

The collection arrangement should include a settlement chamber to allow particles to settle out before the water flows into the supply.

It is also advisable to include a sand or gravel filter after the settlement chamber to remove organic material and small animals. These filters may not remove all micro-organisms and will not remove chemical contamination.

The collection chamber should be constructed to prevent the entry of any discharges from septic tanks or agricultural run-off.


Supplies from where animals graze or manure

Check that the farmer is aware of the drinking water supply and the need to avoid contaminating it by farming activity.

Divert rainwater run-off so it does not flow into your supply. This can be achieved by a small ditch allowing water to run away from the supply.

Fencing should be used to stop animals from gaining access to collection point of the supply.


Supplies stored in a collection chamber or storage tank

These should have watertight and vermin proof walls and lids.

Tops of chambers or tanks should be above ground level to prevent water from surrounding land flowing into them.

Any overflow pipes or vents in chambers and tanks should be designed to stop animals and debris from entering them.

The collection chamber should not be close to any soakaway or drain.


If you supply water to others

If you supply water to other people in the course of a business, you have a duty of care towards customers for the safety of water you supply.

If you think the water is unsafe, you may have to:

  • Advise customers to boil all water for drinking or food production
  • Use or suggest the use of bottled water

How to avoid water contamination advice sheet