What are the main risks to the safety and quality of water in my well?
The main risk to your well is contamination from human or animal waste. Many areas in Ireland have high groundwater vulnerability, which makes contamination of well water more likely. If your well is vulnerable to contamination and is not properly constructed it is possible that human or animal waste from septic tanks, landspreading or runoff from the surrounding land may enter your well. Contaminated water can make you or anyone who consumes the water ill. If you are concerned about your well water, contact your local authority or your HSE Environmental Health Officer for advice. If you suspect that your water may be contaminated it may be advisable to boil your water until you have had your well water tested.
I am using a deep well, how can it be contaminated?
While a shallow well is likely to be vulnerable to contamination, a deep well is not necessarily protected against contamination. Contamination can travel over the top of the well casing (e.g. if the wellhead is below ground), down the sides of the casing (if not properly sealed) or can travel through the soil into the well. Contamination of groundwater through abandoned boreholes nearby is another potential risk. Unless the well is properly constructed, sealed and cased then it may be vulnerable to contamination from contaminated water from the surface.
Where can I get my water tested?
Your local authority Environment Section or the HSE Environmental Health Officer will be able to advise on a laboratory. Alternatively, you can get the name of a suitable private laboratory from the Goldenpages
What should I get my water tested for?
It is most important to get your water tested for E. coli and Coliform Bacteria. The need for other tests depends on the location of your well and the appearance of your water. For example, if your well is in an agricultural area you may need to get it tested for nitrate or if it is slightly discoloured you may want to get it tested for iron and manganese. When making arrangements with the laboratory you should describe any concerns you have about your well water and they will be able to advise on what specific tests should be carried out.
It is recommended that you test your well water at least once a year for microbiological contamination and every three years for chemical contamination.
My water looks and tastes great, does that mean it is safe to drink?
No, it does not mean it is safe to drink. Some contaminants such as E. coli may not cause your water to be discoloured. It is advisable to get your well tested once per year (ideally during poor weather conditions).
If your water is occasionally or frequently discoloured it may be an indication that your well is contaminated from time to time. It is advisable to get your well tested the next time it becomes discoloured and consider boiling that water until you are sure it is safe.
Just because the usual householders are not getting sick, doesn't mean that the well is safe. Visitors may be more susceptible to low level contamination because they may not have developed immunity to the infectious organisms that may be in your well.
My well is contaminated what should I do?
You should check your well to see if there are any obvious signs of contamination such as recent landspreading or cattle too close to your well. Protecting the catchment area of your well is one of the best ways to protect the quality of your water. You should also check to see is there any ingress of water into the borehole.
If your well is contaminated with E. coli or Coliform Bacteria you should boil the drinking water from the well until you are sure it is safe to drink and cook with.
You should sterilise your well (see How do I disinfect my well question) and see if this resolves the contamination (after retesting). If this is not successful in restoring the quality of your water you may need to consider improving the protection of your well and/or installing an appropriate treatment system. Once-off disinfection cannot replace a treatment system if your supply is always or often contaminated.
If your well is contaminated with a chemical parameter you should contact your local authority for advice in the first instance.
You may also consider connecting to a public or group water scheme.
I think my well is being contaminated by nearby activity, what can I do?
The first step is to talk to your neighbour about the suspected cause of contamination. It may be that your neighbour is unaware of the location of your well or the consequences of their actions. If this fails you should make your complaint in writing to the relevant local authority or use the EPA “See It, Say It” app to report the incident.
My water becomes discoloured sometimes, is this something I should be concerned about?
Yes, if your water becomes discoloured at certain times (e.g. after heavy rainfall or when slurry is spread on land nearby) then it is possible that surface water is getting into your well which is likely to be contaminated. You should get your well tested when it becomes discoloured. If you suspect that your well is contaminated with infectious organisms (bacteria / bugs / germs), you should boil your water before using it for drinking, washing teeth, preparing food and making ice until you know that the water supply is safe.
How do I disinfect my well?
This method is for the disinfection of a well water supply, water storage tank, water carrying pipe work and hot and cold-water cylinders. Approximately 1,100 litres of water will be used.
Caution: if you have a filter or any other type of water treatment on any part of your system, consult your supplier before following this procedure. Heavily chlorinated water may affect the filter or the chlorine may be absorbed by the filter rendering the procedure ineffective.
1. To 25 litres of water add 5 litres of a 1% w/v solution of Sodium Hypochlorite. While we do not endorse any individual products, any one of the following products may be used diluted in 25 litres of water.
(a) 2.5 litres of Milton fluid (or 50 tablets) or similar products with 2% w/v Sodium Hypochlorite.
(b) 0.5 litres of Sterichlor or similar products with 10/11% Sodium Hypochlorite.
Disinfection products sold for use on the farm will be acceptable for use in disinfecting wells. However, it is important to seek advice about their use and it is advisable to always use the products in about 25 litres of water.
2. Pour half of the solution into the well.
3. Turn on the drinking water tap in the kitchen and let the water run until there is a distinct smell of chlorine from the water. Then turn off the tap.
4. Turn on all other taps and let the water run until there is a distinct smell of chlorine from the water. Then turn off the taps.
5. Pour the other half of the solution into the well. Turn off the well pump and ensure that the well is covered properly. Allow to stand overnight or for at least 8 hours.
6. After at least 8 hours reconnect the pump. Turn on all taps and let the water run until the smell of chlorine is gone. Turn off all taps.
7. Arrange for the water to be tested.
N.B. This method is only suitable as a once off shock disinfecting procedure and cannot replace a proper treatment system if your water supply needs continuous disinfection.
Where can I get information on treatment systems for my well?
The type of treatment suitable for your well depends on the results of testing. You can get a list of suppliers of water treatment systems in the Goldenpages. You should advise any potential suppliers of the results of testing so that they are aware of what treatment is required.
Are there any grants available to improve the quality of my well?
Yes. Grants are available from your local authority where improvement works are necessary to address a serious deficiency in the quality of water. The grant can cover the drilling of a new well, rehabilitating an existing well, construction of pumps house and associated works or the provision of treatment. You should go to your local authority website for more details on the application process.
How far away should my well be from my septic tank?
Wells should be sited upgradient if possible and as far away as possible from wastewater treatment systems. The minimum recommended distance between a wastewater treatment system and well varies from 15m to 60m depending on the slope and soil type and is set out in the Code of Practice for new builds - Site suitability assessment.
How far away should landspreading be from my well?
Landspreading of organic or soiled water (e.g. slurry) is not permitted within 25 m of a private well/spring. Furthermore areas for the storage of farmyard manure, slatted sheds, slurry storage and silage clamps should be at least 50 m from a private well. The farmyard itself should be 15 m from the private well/spring.
Is it safe to store chemicals (e.g. fertilisers, paints, diesel, pesticides, bleach etc.) near my well?
No. Chemicals should be stored in a safe place away from any wellhead or the contributory zone (catchment) from the water supply so that accidental spillage will not result in the chemicals getting into your well and causing contamination.
My home heating oil or fuel storage tank is near my well, should I be worried?
If the tank is within 30 m of your well you should make sure any spills or leakages from the tank into the well or the surrounding soils will be contained. To do this you should have a properly constructed bund around the tank. If you notice you have to refill your tank more frequently than normal this may indicate there is a leak in the tank or pipework. This should be investigated as soon as possible. If you become aware of a spillage you should report this to your local authority and arrange for your well to be tested.
Where can I get information on drinking water quality standards?
You can get information on the current drinking water quality standards from the most recent EPA reports on The Quality of Drinking Water in Ireland.
Where can I get information on health?
For information on your or your familieis health contact your local HSE Environmental Health Officer. The HSE has published information on the risk of illness from well water, E Coli (VTEC) and cryptosporidiosis. The HSE cautions against switching from public water supplies to existing priavte wells.
My water smells sometimes, what is causing this and should I be concerned?
There are several types of possible smells from your well, all with different causes. The most common types of odour are rotten eggs (from sulphur reducing bacteria), mustiness, sewage/slurry, hydrocarbons (i.e. petrol, diesel or kerosene) and chlorine (if the well has been disinfected). Some of these odours may indicate a risk to your health and you should arrange for your well to be tested. You should boil the water if you suspect contamination with infectious organisms (bacteria / bugs/germs). You should advice the laboratory of the odour you detect in the water when getting it tested.
Some contaminants such as E. coli may not cause your water to smell. Even if there is no odour it is advisable to get your well tested at least once per year (ideally during poor weather conditions to rule out breakthrough contamination when the supply would be more vulnerable).
How far away should landspreading be from my well?
Landspreading of organic or soiled water (e.g. slurry) is not permitted within 25 m of a private well/spring. Furthermore, areas for the storage of farmyard manure, slatted sheds, slurry storage and silage clamps should be at least 50 m from a private well. The farmyard itself should be 15 m from the private well/spring.
The Householder Information on Private Wells section of our website has detailed information and useful guidance, including frequently asked questions, in relation to protecting, testing, treating and maintaining your private well.