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Lead in drinking water

If your property has lead plumbing, it is possible that there is lead in your drinking water. 

The amount of lead which dissolves into drinking water can depend on: 

  • the length of lead pipework involved;
  • how long the water is sitting in the pipe;
  • the temperature of the water; and
  • whether your water is hard or soft i.e. the water chemical characteristics.

Wherever lead piping is present in the supply pipe or internally in the property, there is a risk that lead may dissolve into the drinking water.

If your water has not been tested, can you take precautions? 

  • Use only water from the cold water tap in the kitchen for drinking, cooking and making baby formula. This is called the 'rising main'. It comes straight into your house from the water mains. The water from this tap is usually moving and flowing and has not been stagnant (still or stationary). Water from other taps in your house may have been stagnant in tanks and pipes for longer periods of time and, therefore, more likely to have a higher level of lead. 
  • Flush the water before use. If the tap has not been used for many hours, running (flushing) the water before using it for drinking or cooking may lower the level of lead. However, the only way to know if you have lead in your drinking water, and if flushing lowers it, is by testing it before and after flushing.
  • Alternatively, you could use bottled water.

If your water has been tested and is still above 10µg per litre (10 microgrammes per litre) after flushing what can you do?

  • If after running (flushing) the water the level of lead stays above 10 µg per litre, you should use safe drinking water from some other source. This is especially important for pregnant women, bottle-fed infants and young children.
  • Even if the level stays above 10µg per litre, you can use the water for toilet flushing, showering and bathing, laundry and dishwashing. 
  • Boiling water will not remove lead from the water.

If you want to test your water for lead: 

  • You should use a laboratory with accreditation (approval) for testing for lead in drinking water. Using an accredited laboratory means you have independent assurance that the test is carried out properly. 
  • You should take a sample before and after water has been flushed through the pipe for 3 minutes.

It is important to understand that:
A single test for lead in water may not provide a full picture of the lead levels in the drinking water at your property. This is because the amount of lead in water can be influenced by a number of factors, including the length of a pipe, the length of time water has been standing in a pipe, the temperature and the chemical nature of the water. This means that samples taken from the same tap at different times of the day or at different temperatures can give different results.

The Irish National Accreditation Board (INAB) assesses and certifies laboratories. It lists all accredited laboratories on its website and you can check with it for suitable laboratories in your area. It is a good idea to phone more than one laboratory as prices can vary. Please view their website for more information

  • Regular intake of even low levels of lead can affect your health. 
  • The greatest health risk is for babies in the womb, infants and young children.
  • Bottle-fed infants are especially at risk because, for the first 4-6 months of life, all of their food comes from milk-formula which is made up with drinking water. 

For more information and advice on the health effects of lead in drinking water, please visit the FAQ section of the HSE website.

Drinking Water, as produced by Uisce Éireann, is free from lead.  

While there are currently no known lead water mains in Ireland - internal plumbing, service connection pipes and shared service connections may contain lead pipework. If your property was built up to and including the 1970s it is likely that the pipework within the property boundary contains lead. It is estimated that there are 180,000 homes in Ireland, together with public buildings, schools, medical centres and other buildings over 40 years old, where lead was the normal plumbing material.

Therefore it is possible that there is lead in your drinking water. Lead pipework can dissolve low concentrations of lead into drinking water as it passes through.

  • Lead was predominantly the material in service connections to buildings and in internal plumbing up to and including the 1970s, however, lead has also been used for carrying water for centuries.
  • Uisce Éireann's records currently show there are no lead water mains in Ireland.
  • There are still some lead pipes in the public network, but these are mostly in the short pipes connecting the (public) water main to the (private) water supply pipes. In most cases, 90% of the supply pipe is within the private property. 
  • In addition, some terraced housing schemes built pre-1970 were supplied with water through a shared backyard pipe, which may have been made of lead. 

  • When water comes in to contact with lead, particularly when it is left standing in a pipe for a period of time, the lead can dissolve into the water at low concentrations. This process is referred to as plumbosolvency. The amount of lead which dissolves into drinking water can depend on the length of lead pipework involved; how long the water is sitting in the pipe; and temperature; and the chemical characteristics of the water. 

  • If your property was built up to and including the 1970s it is possible that you may have lead pipes.
  • If your property was built up to and including the 1970s but has been modernised since, including the replacement of all pipework from the stop valve outside the property boundary to the kitchen tap, it is unlikely that there is lead in your supply system. If you are unsure:-
  • Inside the Property: Look for the point where the water pipe enters the house and check as much of the pipe as possible. Or you can look behind the cupboards in your kitchen and find the pipe leading to the kitchen tap, check if it is lead along as much of its length as possible.  Unpainted lead pipes are dull grey in colour and the joints appear to be "swollen".  They are also soft, and if you scrape the surface gently with a knife you will see the shiny silver coloured metal beneath.  
  • As a guide, other pipe materials have the following appearances:
    • Copper - bright, hard and dull brown
    • Iron - dark, very hard and may be rusty 
    • Plastic - may be blue, grey or black

  • If you are in any doubt, it is recommended that you retain the services of a qualified plumber to check the type of pipework in your premises.
  • If you are not the owner of the property in which you live, please pass this information on to the property owner.
  • More information can also be found in the Environmental Protection Agency (EPA) and the Health Service Executive (HSE) "Drinking Water Consumer Advice Note No 1 - Lead (Pb)" available at

Uisce Éireann is responsible for the pipes under the road or paths to the outer edge of the boundary of the property. This is referred to as the public side connection. The property owner is responsible for the pipe from the outer edge of the property boundary to the building and all the inside plumbing. This is known as the private side connection.

There are other types of connections (eg where the connection is shared or comes through the back garden) but these are not common.

Yes. The Department of Housing, Planning, Community and Local Government has established a grant scheme that is available to homeowners to assist with the cost of replacing pipework containing lead in properties. The grant scheme is administered by Local Authorities. For more information on how to apply for a lead replacement grant scheme, please visit the the Department of Housing, Planning, Community and Local Government website.

Uisce Éireann has included a customer opt-in step by step guide as part of the Lead in Drinking Water Mitigation Plan. As part of this scheme Uisce Éireann commit to replacement of the public side lead service when the customer has replaced the private side lead service.
The application form can be found here.

Corrective Water Treatment for the protection of public health

Drinking water must undergo a complex treatment process to ensure it is clean and safe to use. Depending on the source type, the treatment process can involve the addition of chemicals to the water. Adjustment of pH levels, in conjunction with orthophosphate treatment, is a corrective water treatment used to reduce the corrosion of lead pipes and the subsequent dissolving of lead into drinking water, with the aim of protecting public health.

The United States Environmental Protective Agency (USEPA) has identified orthophosphate treatment as the most effective method (apart from replacing any lead pipework and fittings) for reducing the presence of lead in drinking water.

Note: Orthophosphate treatment involves adding orthophosphate to drinking water.

Orthophosphate added to drinking water is in the form of an additive called phosphoric acid. This is a clear, odourless liquid and is entirely safe for human consumption. Phosphoric acid as a food additive (E338) is approved for use in food products, such as dairy, cereals, soft drinks, meat and cheese products. There is 500 times more phosphorus in a glass of milk than in a glass of water treated with orthophosphate.

The average person consumes between  1,000 and 1,500 milligrams  of phosphorus every day as part of a normal diet. The typical concentration of phosphorus ingested from drinking 3 litres of water per day that has been treated with food grade phosphoric acid at 1.5 mg/l Phosphorus, would only be  4.5 milligrams.

Yes, Orthophosphate is a widely used 'corrosion inhibitor', added to treated drinking water in the UK, mainland Europe, USA, and Canada to reduce lead levels in drinking water.

In addition:

  • Orthophosphate is added to drinking water at all water treatment plants across Northern Ireland.
  • More than 90% of the UK's water supply is treated with orthophosphate for the purpose of reducing the plumbosolvency of drinking water.
  • Orthophosphate treatment achieved 99% compliance with the allowable lead limit in drinking water in the UK and Northern Ireland within 3 years.
  • Orthophosphate has been used to reduce dissolved lead in water for over 20 years.

For reference:

Orthophosphate forms a protective coating inside lead pipes and fittings in customer's homes and businesses to help prevent lead from dissolving into drinking water.

Uisce Éireann expects that it will take between 6 to 24 months of orthophosphate treatment before a substantial reduction in lead levels occurs. This is due to the time it typically takes for the protective coating to form inside the lead pipes and fittings, and to develop fully throughout the entire water distribution system.

Under the Uisce Éireann Lead Mitigation Plan, Uisce Éireann proposes to implement orthophosphate treatment where it is technically, economically and environmentally viable to do so. Uisce Éireann is proposing to investigate the roll-out of orthophosphate treatment at up to 400 water treatment plants, subject to a site-specific assessment at each plant.

A site-specific assessment will also be carried out on each water supply zone, including Environmental Assessment Methodology (EAM) and Appropriate Assessment (AA).

Yes. This is not a new method for reducing lead levels; in fact it has been used successfully in many countries for several years. The HSE has recognised that there is no health concern linked to the addition of orthophosphate to drinking water following extensive use across the UK (for over a decade) and in many other major metropolitan settings, such as New York, where reduced lead levels in drinking water had resulted.

Any additives used as part of the corrective water treatment process for the protection of public health, will be required to be on the UK Drinking Water Inspectorate 'List of Approved Products for use in Public Water Supply in the United Kingdom'. The products in this list have been assessed for safety, for use in water supplies.

No. Orthophosphate is a tasteless, odourless, food-grade additive.

It is not practical or feasible to selectively supply orthophosphate treated water to homes/properties where there is lead pipework or fittings. The addition of orthophosphate will have no negative impact on you, your family or your business.

Uisce Éireann recognises that the most effective long-term strategy is to remove all lead pipes and fittings from the entire drinking water supply network. This is also the recommendation of the World Health Organisation ( WHO ). However as the majority of lead pipes and fittings are located within private property (i.e. inside the property boundary), the responsibility to replace this lies with the customer (property owner), and not Uisce Éireann.

The Uisce Éireann Lead Mitigation Plan, and the Government's National Lead Plan, highlight the need for collective action, involving property owners and a number of public and private stakeholders over many years to reduce exposure of people to lead in drinking water.
International experience has shown that proactive replacement of public side lead service connections by water companies does not achieve significant benefits unless the customer replaces privately owned lead supply pipes at the same time.

In situations where any public-side lead is replaced by Uisce Éireann, it is highly likely that lead levels in the drinking water will continue to be elevated unless and until any privately-owned lead supply pipes and fittings are replaced at the same time by the property owner. 

If a property owner replaces the lead pipework on their property, Uisce Éireann will also replace the pipework between the water main and the property boundary.  
The Government has introduced a grant scheme to help homeowners with the cost of replacing lead pipes and fittings containing lead inside the boundary of their property. The grant scheme is administered by the Local Authorities.

For more information on the scheme, please visit the Department of Housing, Planning, Community and Local Government Website.

Uisce Éireann will be testing water at randomly selected customer taps throughout the distribution network of each water supply zone to monitor the effectiveness of orthophosphate treatment and levels of lead present. Samples will be taken in the Water Supply Zone every two months after the commencement of orthophosphate treatment. If a Lead exceedance is detected during monitoring, you will be informed in writing of the result. These results are also reported to the HSE and the EPA. 

Uisce Éireann has undertaken laboratory testing to assist in quantifying the optimum treatment dose and to ensure that phosphate levels are kept as low as possible. Additional phosphorus has the potential to impact receiving waters through nutrient enrichment and the increase of algal growth in slow moving fresh water. Uisce Éireann, in consultation with the EPA and other environmental stakeholders, is in the process of developing a comprehensive environmental assessment methodology to assess any potential impacts and ensure that the necessary actions are undertaken to protect the natural environment. Wastewater treatment plants have treatment stages, which reduce the levels of phosphate being discharged to the receiving waters. Uisce Éireann will closely study the potential environmental impacts from orthophosphate treatment on the receiving waters for each water supply zone.  

When investigating the feasibility of orthophosphate as an interim treatment, a site specific environmental assessment will be carried out on each water supply zone, including Environmental Assessment Methodology (EAM) and Appropriate Assessment (AA). 

Uisce Éireann will prepare a programme for decommissioning orthophosphate treatment from the water supply when Uisce Éireann has completed public side lead service connection replacement, and the annual sampling programme indicates that the risk to households has reduced to compliant levels. Our expectation, based on the experience in other countries, is that orthophosphate treatment will continue as a mitigation measure for as long as lead pipes remain in properties.

Yes. The use of orthophosphate was highlighted in the Uisce Éireann draft Lead in Drinking Water Mitigation Plan - Issues Paper that was published for non-statutory public consultation in June 2015. There was also a period of public consultation on the full Lead in Drinking Water Mitigation Plan.

Customer Opt-In Step By Step Guide and Application Form

Uisce Éireann has included a Customer Opt-In Step By Step Guide as part of the Lead in Drinking Water Mitigation Plan. As part of this scheme Uisce Éireann commit to replacement of the public side lead service when the customer has replaced the private side lead service.

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