With over 700,000 people in Ireland getting their water from private wells, it might be worth considering how heavy rain – and there’s been plenty of that this year – can impact on the safety of the water sourced from them.
According to the Environmental Protection Agency (EPA), private wells should be tested at least once a year, but ideally should also be tested after periods of heavy rain, as contamination is likely to be high at that time.
However, regular testing of well water is important as water can be contaminated at any time, and not just as a result of rain.
According to the EPA, microbiological testing typically costs around €65, while a full drinking water test will cost about €130.
If the water is found to be contaminated, the following steps should be considered:
- Eliminating the source of contamination by moving it/them away from the well, if possible, or by protecting the well head;
- Disinfecting the well, supply pipe and internal plumbing;
- Installing treatment (this will depend on the specific type of problem but in most cases will be a form of disinfection such as ultraviolet light;
- Connecting to a public or group water supply if one is available nearby.
According to the EPA, many people assume that their well water is safe to drink, and do not get it tested. However, the agency says that many private wells may contain E.coli.
Although most strains of E.coli are harmless, some strains, such verocytotoxigenic escherichia coli (VTEC) can cause severe illness.
The EPA advises that a well should be located upslope and as far as possible from potential sources of pollution.
Wastewater systems, including septic tanks, should not be located within 30m of your well. This distance should be increased if your well is downslope of the system.
The EPA also advises that you check that slurry is not being spread on land too close to your well or on bare rock where it may contaminate the groundwater. Land spreading should not be carried out within 25m of your well.
As well as that, household or farm chemicals such as pesticides, oils, and paints should not be stored within 5m of the well head and in any way that they could leak or spill into the top of your well.
Fuel storage tanks should be at least 30m from the well and animals should be fenced-off to a distance of least 3m from the well head.
In terms of well structure, the EPA says that the well head should be protected and there should be no gaps around the top of the well water casing.
Existing well-owners may be eligible for a grant to drill a new well or for improvements to existing ones. More information on these grants is available from local authorities.