Advice for householders using private wells

Advice for householders using private wells

If your house is served by a private well, you are responsible for the quality of your well water. Your supply should comply with the water quality standards, which protect human health.

Published on: 12 Jul 2019

Just because the water comes from underground does not mean it is OK to drink.  Even if your water is crystal clear it may still be contaminated, as many of the bugs in water are invisible. If you suspect that your water may be contaminated with bacteria it may be advisable to boil your water until you have had your well water tested. 

Polluting activities such as domestic wastewater treatment systems or septic tanks, farmyards and land-spreading of slurry and grazing cattle may pose a risk to the water in your well.  One litre of domestic wastewater contains around 1 million E. coli bacteria, but it takes just a few organisms of one type of E. coli (VTEC) to cause severe human illness. 

Polluting matter may seep into the ground and contaminate the groundwater itself and then it gets pumped into your well OR it may flow over the land surface and down around the top of your well and into the groundwater, which is then pumped into your well. 

‌The most common problem associated with private wells is poor well construction. It is very important that the well is drilled properly, grouted and lined to make sure that polluting matters cannot get into the well from the ground surface or from shallow groundwater.  It is recommended that you secure your wellhead from animal access (e.g. putting a fence around your wellhead).

To ensure that your health is not at risk from contamination of your water supply, you should check that your well is adequately protected.  Make sure that contamination is not getting into your well by checking

  • If your wellhead is sealed?
  • If the well is lined and grouted?
  • If surface water or runoff can get into the well?

The best way to ensure your water is safe is to look for any potential sources of contamination such as:

  • Domestic wastewater treatment systems such as septic tanks;
  • Landspreading of slurry;
  • Storage of chemicals such as disinfectants, pesticides, paints;
  • Fuel storage tanks for home heating oil;
  • Abandoned boreholes.

For further information on protecting your well please refer to the EPA Leaflet available to download at