Testing and Treatment Options for your Private Well

Where can I get my well water tested?

Drinking water from private wells is at risk of contamination.  It is estimated that up to 30% of private wells may be contaminated  occasionally with E. coli (an indicator of recent pollution by human or animal waste).

As private wells are not regulated, it is up to the well owner to arrange to have their well tested.

To ensure that your drinking water is safe you should get it tested.  Test it preferably at least once a year for bacterial contamination and once every three years for chemical contamination, especially after heavy rain.  Remember, a test can only tell you about the quality of the water at the time of the test - the quality may change at different times.  If concerned arrange for a retest of  your water.

At a minimum, test for E. coli and coliform Bacteria.  The need for other tests depends on the location of your well and the appearance of your well 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.   You should consider testing the well if there is a vomiting or a diarrhoeal infection in the family.  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.

A number of private laboratories are available to carry out the analysis.  Your local authority Environment Section or Environmental Health Officer will be able to advise on a suitable laboratory.  Alternatively, you can get the name of a suitable private laboratory from the Goldenpages. 

These laboratories are offering a discount on the cost of analysis if you quote the promotional code 'EPA 2014' when arranging the testing.  It is important to follow the instructions of the laboratory when taking and handling the water sample as this may affect the reliability of the results.

Do I need to treat my well water?

If test results indicate that your well is contaminated, you should take action to protect it.  Also, if it is contaminated with infectious organisms (bugs, bacteria, germs), the water should be boiled until the well water is safe to drink.

You may need to install some type of treatment if your well is located too close to a polluting activity or if the water is still contaminated after you have taken steps to protect the well.  There is no “one size fits all” solution.  The type of treatment depends on the quality of your well water.  Remember that any treatment system must be properly maintained and operated to do its job properly, otherwise it could pose a health risk.

Below is a list of the main treatment types used in private wells:

• Chlorination – chlorine is the most commonly used disinfectant in Ireland however; it may not be suitable for on-going disinfection in private wells due to the low doses required. It is suitable for disinfecting a well on an intermittent rather than on-going basis.   It protects against pathogens but not against Cryptosporidium.
• UV treatment – Ultraviolet light is a very effective disinfectant at killing pathogens and Cryptosporidium, if used correctly. UV will only work properly if the water is clear and contains low levels of iron and manganese (which can cause fouling of the lamp).

• Jug filters/cartridge filters – these types of filters can remove certain substances, which can lead to improved taste and acceptability of water but while most will generally not remove infectious organisms, certain specialised filters will.
• Water softener – these are used to reduce the hardness of your water to prevent damage to your appliances.  These are ion exchange units where, in most cases salt is added to remove the hardness.  Water softened in this way  can have high levels of sodium (Na) in it.  It is not suitable for drinking, cooking or preparing babies bottles but it can be used for other purposes such as showering or washing.
• Reverse osmosis (RO) – RO is a membrane based treatment where water is moved across a membrane (using pressure) to remove ions and other impurities.   It may be necessary to re-mineralise water produced by RO.

The type of treatment suitable for your well depends on the results of appropriate testing.  You can get a list of suppliers of water treatment systems in the Goldenpages.  You should advise any potential suppliers of water treatment systems of these results so that they can advise you on the most suitable treatment for the problem.

Any treatment system installed must be maintained and operated in accordance with the manufacturers specifications or it may not do the job it is intended to do and could pose a risk to your health.

Alternatively you should check with Irish Water or your local group water scheme to see if you can connect to a nearby public or group water scheme.