Water and Drainage

Unregulated Private Water Supplies

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What is an unregulated private water supply? An unregulated private water supply is any supply that is not regulated by a Water Authority (i.e. Fingal Co Co) or Irish Water. The definition is set out in the Drinking Water Regulations 2014. It is any private supply that provides less than 10 cubic meters per day of water or serves less than 50 people (15 houses) and does not serve a public or commercial activity, or where the Local Authority is satisfied that the quality of the water used in a public/commercial organization has no influence either directly/indirectly on the health of its customers ( e.g. Water used solely for a truck wash). Examples of public or commercial activities include schools, restaurants or hotels. 

County Councils as Water Authorities are required by the EC Drinking Water Regulations 2014 to provide owners and users of unregulated private water supplies with information about the risks of contamination and with advice about what they can do to protect and keep their supplies safe. 


Safe drinking water is essential for good health. Private water supplies must be carefully located, properly constructed and protected.  The majority of private water supplies are safe to drink however some sources may become contaminated with bacteria and other microbes and with chemicals. Some microbes are harmless but others may cause illness in vulnerable people such as the elderly, young children, pregnant women and those who are not in good health. If you are concerned about the safety of your water supply you should get the water analyzed. 

Springs are natural outlets of water that has flowed underground. Springs can be from shallow or deep groundwater. Dug wells vary in depth and construction. Boreholes are generally drilled deep into rock. Springs, wells and boreholes that draw water from close to the surface are more likely to be contaminated than sources that draw water from deeper underground. Water levels in springs, wells and boreholes vary throughout the year and there may also be changes in microbiological quality and water chemistry. Almost all contamination of groundwater originates from polluting activities at or near the ground surface. 

The water from streams, rivers, lakes and ponds is not recommended for human consumption unless such water is fully treated. The quality of surface waters varies depending on weather conditions and activities in the catchment. 

Know your supply and keep your water safe.

If you have a private supply, you and any shared users are responsible for its protection. Check the source area and system regularly.

Location: It is essential that the well/borehole source is carefully located up-gradient and as far as possible from any potential sources of contamination. Find out the well or borehole construction and at what level the water enters.

A borehole must be constructed properly using casing with a full cement grout seal to prevent shallow groundwater from entering the borehole. (See IGI Guidelines) Ensure that the top of the borehole casing is above ground level and in a watertight manhole chamber to prevent surface water getting into the supply.

Ensure that the top of the casing is covered to prevent anything falling into the borehole. Divert rainwater run-off so that it does not flow into or toward the source or pond nearby. The source should not be close to any septic tank or other wastewater treatment system, percolation area, filter bed, discharge, soak-away or drain.

You can see a diagram of a correctly installed well at the end of this page.

The source should also be located as far as possible from farm yards, slurry and manure pits and silage storage areas.

Fertiliser, pesticides or other chemicals should not be stored near a source or in a pump house. Oil tanks should not be located near a source and should be of double wall construction and bunded to include the off take point.

Is the supply treated? If so is the treatment system in good order and serviced regularly? You are responsible for the maintenance of any treatment system.


If you know that your supply is contaminated you should remove the source of that contamination if possible. If not possible you should select a good site and construct a new well/borehole to modern standards that will exclude any contamination form shallow groundwater (See IGI Guidelines).

Well grants are available but must be approved prior to any work being carried out. Contact the Water Services Section, details are at the end of this page.

Get Your Supply analysed

It is advisable to have your private water supply tested once a year for bacterial quality and every three years for chemical detection. You can arrange to have a sample tested using a private or public laboratory. The owner of a private water supply is responsible for any costs incurred with regard to water testing. Remember that a test can only tell you about the quality of your supply at the time of the test, and the quality of water may change.

Consider treating your supply for extra security. The source of your water should not be polluted but you may add treatment to further ensure a safe supply. The choice of treatment must suit your supply. In order to be effective, treatment systems must be maintained and it is important to consider this cost prior to purchase.

Consider Your Pipe Work

Lead: Can be picked up from lead pipe work. Water with high lead levels is not suitable for human consumption. Replace old lead pipe work with Class C UPVC pipe work.

Copper: You may notice a blue tinge or blue/green stain on sanitary fittings. This may be because your water supply is slightly acidic and is dissolving copper from pipes or the hot water cylinder. Test the water for copper and check for possible leaks. Use non metal pipes for drinking water if your supply is acidic.


The most significant risk to private wells is from leaking drains or malfunctioning septic tank and other sewerage treatment systems. House owners should ensure that all sewerage systems are properly constructed, installed, maintained and serviced.

Another possible source of bacteria is from animals. Water supplies drawn from farmland where animals graze or where excessive manure or slurry is spread are most at risk, particularly where rainwater can run directly off farmland into the water source area.


Possible sources of chemicals in a water supply include industrial premises, workshops, quarrying, road and driveway run-off. Farming and forestry (use of fertilizers, pesticides and sheep dips) are other possible sources. Artificial fertilizers and animal waste contain nitrogen. Water with excessive levels of nitrates is not be suitable for bottle-fed infants under six months.

Water Hardness 

A natural characteristic of groundwater sourced in limestone areas such as in much of Fingal County Council area. Hardness is made up of calcium and magnesium dissolved by the passage of water through soil and rock. Temporary hardness is made up of calcium carbonate and this hardness precipitates out of water when heated resulting in lime scale deposits. Hard water is good for health. Calcium and magnesium are good for bones teeth and the heart. The World Health Organization does not set an upper limit. Hardness may be removed from household water however water with increased sodium/salt content is not recommended for human consumption.

Iron and Manganese 

May be present in your supply and if excessive removal is recommended to make the water acceptable. The presence of iron and manganese is not considered harmful to health. Radon and uranium may be present in the water source because of the nature of the rocks in the catchment, particularly in the granite areas. High levels may be harmful to health.

For advice please contact

The Radiological Protection Institute of Ireland. 
Telephone: (01) 2697766.

Diagram of a Correctly Sealed Well

Diagram of a Correctly Sealed Well

Contact Us

Water Services Section, 
Fingal County Council,
Grove Road, 
Dublin 15
Telephone : (01) 8905000


Health Service Executive
Environmental Health Officer
Telephone : (01) 8906275