Water quality


This document deals with the quality of water that is provided for human consumption – drinking, preparing food, making ice, making drinks with water and brushing teeth. For regulation purposes, this is called ‘drinking water’.

Drinking water comes from two different sources. Water from lakes, rivers and streams (surface water) will almost certainly have to be treated to make it safe to drink. Water from springs and boreholes (groundwater) may have to be treated, depending on the quality of its source.

The Environmental Protection Agency (EPA) publishes information on drinking water quality and the Health Service Executive (HSE) publishes information about drinking water and health issues. Irish Water has published FAQs on water quality.

The Food Safety Authority of Ireland publishes information on bottled water. The EPA publishes information on bathing water.

Lead and drinking water

Lead can be present in drinking water, as lead piping, lead solder and lead-lined water tanks were commonly used in plumbing up to and including the 1970s, so some people may still be getting water through these older plumbing systems. Lead is a danger to health, especially for young children, pregnant women and babies fed on formula, so water for drinking and cooking should contain as little lead as possible. The legal level of lead in drinking water is 10 micrograms per litre.

If you are concerned that there might be lead in your drinking water, you can contact Irish Water for advice – see ‘Contacts’ below. If your water is not provided by Irish Water, contact your group scheme or your local authority.

There is a grant scheme in place to help low-income households with the cost of remediating domestic lead piping.

The HSE has published a joint position paper on lead in drinking water (pdf) with the EPA, along with a set of FAQs. A national strategy to reduce lead exposure (pdf) has been published and Irish Water is preparing a national mitigation plan (pdf).

Other factors affecting water quality

Several factors can affect the quality of drinking water sources (raw water). If there is high rainfall, for example, extra organic material may be washed into rivers and streams. Water treatment plants need to be able to deal with this. If rainfall is low, these sources can dry up altogether. Other factors affecting water sources include agricultural practices and the type of soil and underlying ground.

Factors affecting treated drinking water (finished water) include breakdown in the treatment process; lack of disinfection and filtration (or problems with them); problems with equipment; power outages or dirt in distribution pipes. Sometimes, poor quality is due to the water being drawn from an unsuitable source and the best solution is finding an alternative source.

You can find information about water pollution on the ENFO website.

Contaminated water

As well as the effects of lead (see above) infectious diseases caused by bacteria (like E Coli - also known as VTEC) and parasites (like Cryptosporidium (pdf)) are the most significant health risks associated with contaminated drinking water. These contaminants are of particular danger to children, older people, pregnant women and people whose immune systems are compromised. A change in the colour, taste or smell of water can indicate a problem. However, such changes are not always present, even if the water is contaminated.

Septic tanks: Leakage from septic tanks or other domestic waste water treatment systems can contaminate drinking water - see Is your well at risk from your septic tank? (pdf). All domestic waste water treatment systems, including septic tanks, must be registered and an inspection system is in place. The owner of the system must ensure that any necessary remediation is carried out, following inspection.

Read more in our document on inspection of septic tanks and other domestic waste water treatment systems and on the EPA's website.

Treatment of drinking water

Most water supplies need to be treated to bring them up to the standards required – see Standards and monitoring below. Groundwater can be of high quality but this depends on the soil and rock formation and on the agricultural practices near the source. It may only need precautionary disinfection. Surface waters almost always contain impurities and these have to be removed by a suitable treatment process, including coagulation, filtration and chlorination.

Under the Fluoridation of Water Supplies Regulations 2007 (SI 42/2007) fluoride is added to the water in all public supplies. You can read more about fluorides on the website of the Expert Body on Fluorides and Health established by the Department of Health.

Standards and monitoring

All water for human consumption must be free from micro-organisms and any substances which, if found in sufficient numbers or concentrations, would endanger public health. These standards are contained in the European Union (Drinking Water) Regulations 2014.

These Regulations give formal effect in Irish law to the EU Drinking Water Directive of 1988. They establish strict quality standards for water used for human consumption and set out the maximum and guideline values for various different physical, bacteriological and chemical contaminants. Not all of these parameters are monitored at the same frequency. A group of 8 to 14 contaminants are monitored regularly and others are monitored at set times, based on the size of the supply.

The EPA has published detailed handbooks on the implementation of the Regulations in private water supplies and public water supplies.

Monitoring of drinking water supplies

How water supplies are monitored for adherence to the standards set out in the Regulations depends on their size and on whether or not they supply water to the public.

Large supplies (supplying more than 50 people or producing more than 10 cubic metres of water a day) and small supplies that provide water to the public (such as businesses, schools or social clubs) must meet the standards and they are monitored under the Regulations.

The EPA’s drinking water reports show that the quality of water in regulated water supplies is high.

Small water supplies (supplying fewer than 50 people or producing less than 10 cubic metres of water a day) and supplies with no public activity should also meet the legal standards, but they are not monitored under the Regulations. It is up to the owner of the supply to make sure that they meet the standards. At present, over 10% of consumers in Ireland get their drinking water from such unregulated supplies, the quality of which is not officially monitored.

Public water supplies

The EPA is the supervisory authority for public water supplies. Irish Water is responsible for monitoring such supplies and for informing the EPA of non-compliant water monitoring results. The relevant local authority prepares short-term and long-term plans to address the problem, for approval by the EPA. The EPA has legal enforcement powers if appropriate action is not taken.

Private water supplies

Private water supplies include private group water schemes, public group water schemes and other private supplies such as a water supply owned by a developer. This category also includes small supplies that provide water to the public.

A private group water scheme is one where the entire water supply (including the source, treatment plant and distribution network) is owned by a group of community trustees. These are commonly members of the National Federation of Group Water Schemes. A public group water scheme is where the water comes from a public drinking water supply but the distribution system is owned by a group water scheme.

Local authorities often monitor private supplies on behalf of their owners or trustees. Some of them employ the HSE to test the water quality and some do it themselves. The trustees or owners of the supply pay the local authority for this service.

In the case of private supplies, the local authority is the supervisory authority. They have the same role that the EPA has for public supplies. If a private water supply falls below the EC standards, the local authority notifies the trustees of the scheme or the owners. The trustees or owners must submit an action programme to the local authority which will address the problem within a certain timescale. The local authority has legal enforcement powers if appropriate action is not taken.

For all regulated water supplies, public and private, the HSE is informed if there is a potential danger to human health and agrees remedial actions with the local authority for the protection of public health.

Monitoring of small water schemes and wells

As noted above, for group water schemes that do not supply more than 50 people or produce more than 10 cubic metres of water per day, the same standards apply but the quality is not monitored under the Regulations. Whoever is responsible for the scheme is responsible for monitoring the water quality.

Similarly, if your water supply comes from a private well, you are responsible for monitoring the quality of your own supply. You must bear the cost of the testing yourself and if your supply is contaminated, you must organise and pay for any treatment that is needed.

The HSE publishes detailed information on the risk of illness from well water (pdf). It recommends that wells should be tested at least once a year for microbial contamination, and at least once every 3 years for chemical contamination. It also publishes information on the risks of switching from a public to a private water supply (pdf).

To get your supply checked, contact the local authority or HSE Environmental Health Officer in the first instance. Alternatively, you can arrange to have a sample tested using a private laboratory. It is not recommended that you take a water sample yourself as equipment has to be sterile.

The EPA has published extensive information for householders on protecting private wells.

Enforcement of standards

The EPA is the supervisory authority for public water supplies and the local authority is the supervisory authority for private supplies. This means that they can legally enforce the standards set out in the Regulations if agreed actions on a regulated water supply have not been taken within the agreed timescale.

A notice (a Direction) can be served (by the EPA on Irish Water or by the local authority on private owners or trustees) to prepare an action programme that will bring the supply up to the necessary standard as soon as possible.

Owners and trustees of private supplies must prepare their action programme in consultation with the local authority.

For group water schemes, it must fit in with the county’s strategic rural water plan under the Rural Water Programme, outlined below. Advice can be obtained from the National Federation of Group Water Schemes.

The owners or trustees must submit the programme to the local authority within 2 months of receiving the notice. It should contain the following information:

  • A description of the quality issues to be dealt with
  • Details of the changes put forward to bring the water supply up to drinking water standards
  • Whether a capital grant under the Rural Water Scheme is needed
  • A timeframe for the achievement of drinking water standards
  • Details of the management or operational changes that may have been made to bring the scheme into compliance with drinking water standards.

If the programme is not produced within 2 months, the person on whom the notice was served is guilty of an offence under the Regulations. On summary conviction in a District Court, they could be liable to a fine and/or a prison sentence.

Agencies involved with water quality

Various public agencies have important roles to play, as follows:

Irish Water and local authorities

Irish Water is responsible for maintaining the public water supplies and ensuring the quality of the water it distributes. Local authorities are the supervisory authority for the water quality of private water supplies that are monitored under the Regulations. They also perform certain functions on behalf of Irish Water under service level agreements. See our document on Water supply.

If a water supply constitutes a danger to human health, Irish Water must take action to protect public health. It does this in consultation with and with the agreement of the HSE. It may issue a ‘Drinking Water Restriction Notice’. Alternatively it may issue a ‘Boil Water Notice’, warning that the water supply is not safe for human consumption unless boiled first. It must ensure that the public are made aware of the dangers as soon as possible.

If you get your water from the public mains system and have doubts about its quality, this may be due to deficiencies in your own plumbing system. If so, you are responsible for fixing the problem. A group water scheme that gets its water from the public mains system is also responsible for maintaining its own equipment.

However, if the problem is with the public mains system, this is the responsibility of Irish Water, which works with local authorities to respond to emergencies relating to water mains leaks and pollution incidents.

Rural Water Programme and monitoring committees

The local authorities administer the Rural Water Programme, which aims to improve the quality and efficiency of group water schemes, small public water and sewerage schemes, and private supplies where no alternative group or public supply is available.

Each county has a strategic rural water plan, pinpointing areas needing improvement and deciding how to make the most of grants and subsidies available for improving and maintaining water supply systems. Local authorities have compiled an inventory of group schemes and take note of the quality of their water supply. The overall aim of the plan must be to deliver water as efficiently and effectively as possible.

An Fóram Uisce monitors and advises on the development and implementation of policy on the Rural Water Programme. There are local committees in each county to enable water consumers to have a say in how the Programme is implemented. Each local authority has a County Liaison Officer to deal with day-to-day issues brought up by the Programme’s implementation.

Health Service Executive (HSE)

Under the Regulations, the HSE must be informed whenever poor water quality poses a potential danger to human health. The local authority then prepares an action programme in consultation with and with the agreement of the HSE.

In some areas, the Environmental Health section in the Local Health Office monitors water supplies on behalf of the local authority to make sure that all water sources meet the required public health standards. The HSE is also responsible for monitoring the fluoride content of public water supplies.

The HSE can also (for a fee) analyse water from a private source, such as a well. The fee cannot be more than the cost of the monitoring.

As noted above, the HSE also publishes advice and guidance on the dangers to human health caused by poor water quality.

Environmental Protection Agency (EPA)

The EPA collects information from Irish Water about the monitoring of regulated water supply schemes and produces a yearly report on the quality of drinking water in Ireland. It has enforcement powers in relation to the drinking water quality of public water supplies. These powers require Irish Water to notify the EPA (as well as the HSE) where there is a potential risk to human health and to comply with their directions.


If you have concerns about the quality of your public water supply, contact Irish Water’s Help Centre immediately.

If you have concerns about the quality of your private water supply, contact your local authority immediately. It will give you information on dealing with contaminated water and on grant assistance for upgrading and maintaining private water distribution systems.

To get your private water supply tested, contact your local authority; the Environmental Health section of your Local Health Office; or a private laboratory.

Irish Water Customer Care |Team

PO Box 860
South City Delivery office
Cork City

Opening Hours: Lines open 24 hours 7 days a week
Tel: (01) 707 2828
Locall: 1850 278 278

Department of Housing, Planning and Local Government

Custom House
Dublin 1
D01 W6X0

Tel: (01) 888 2000
Locall: 1890 202 021

National Federation of Group Water Schemes

24 Old Cross Square

Tel: +353 (0)47 72766
Fax: +353 (0)47 72788

Environmental Protection Agency

P.O. Box 3000
Johnstown Castle Estate

Tel: (053) 916 0600
Locall: 1890 335 599
Fax: (053) 916 0699

Page edited: 12 February 2016