Paul Millard, Technical manager at WRAS (The Water Regulations Advisory Scheme), explains some of the key areas where hospitals and other healthcare premises can act to prevent contamination of the water system, and thus effectively protect patients, visitors, and employees. He also focuses on the accompanying legal and regulatory obligations.

Water safety in healthcare premises is an ongoing challenge, and a key priority for places such as hospitals and surgeries, more so because contaminated water and waterborne infections have the potential to compromise patient health and safety

–        and yet these issues are completely preventable.  WRAS,  the  Water Regulations Advisory Scheme, was set up in 2008 by UK water companies to help individuals and organisations – including hospitals and other healthcare premises

–        comply with the Water Fittings Regulations. This article aims to highlight the key areas where healthcare premises can act to prevent contamination of the water system and effectively protect patients, visitors, and employees.

The Water Supply (Water Fittings) Regulations and Scottish Byelaws

The Water Supply (Water Fittings) Regulations and Scottish Byelaws play an important role in protecting public health, safeguarding water supplies, and promoting the efficient use of water within consumers’ premises across the UK. They set legal requirements for the design, installation, operation, and maintenance of plumbing systems, water fittings, and water-using appliances. The Regulations aim to prevent misuse, waste, undue consumption or erroneous measurement of water, and, most importantly, to prevent contamination of drinking water. These regulations and byelaws apply in all types of premises supplied, or to be supplied with, water by a water company. They apply from the point where water enters the property’s underground pipe (usually at the stop tap at the property boundary), to where the water is used in plumbing systems, water fittings, and water-using appliances.WRAS stresses the importance of selecting only products and materials that have been properly tested, and are suitable for the intended use.

The regulations or byelaws do not apply where a property uses a private water supply and does not have a supply of water from a water company. If a top-up supply from a water company is in place, the regulations/byelaws apply.

Legal duty

A legal duty is placed on all users, owners, or occupiers, and anyone who installs plumbing systems or water fittings and water-using appliances, to ensure that they are installed and used in accordance with these regulations and byelaws. Water Undertakers (the legal name for water companies) are duty- bound to enforce the Water Fittings Regulations and Scottish Byelaws within their appointed water supply areas. They undertake inspections of new and existing installations to check that the regulations and byelaws are being met. Across the UK, there are around 70,000 inspections carried out by water companies each year.

Health risks

A poorly designed and installed water system can encourage the growth of microorganisms, including biofilms which harbour bacteria, fungi, and protista. The presence of pathogens such as Pseudomonas aeruginosa and Legionella pneumophila is of particular  concern where there is the potential to impact vulnerable patients. Pathogens can easily survive in low nutrient environments such as water systems, and these can cause a range of viruses and medical issues. Water can also provide an efficient mechanism  for spreading contamination, which is concerning in any home or business, but even more so within healthcare premises.

When waterborne pathogens are transmitted throughout the premises, the exact cause of transmission is often unknown. Even when infections can be linked to a water source, healthcare professionals can be none the wiser that they are spreading these potentially dangerous pathogens.

Potential sources of transmission include:

  • Poor hand hygiene: pathogens can be spread by improper hand hygiene, but also from washing with contaminated water or splashback from sink drains.
  • Direct aerosol transmission from water to patients: for example, showers, room humidifiers, and cooling towers – people contract Legionnaires’  disease  when they breathe in a mist or vapour containing the bacteria.
  • Indirect transmission: bath supplies and linens washed in contaminated water; using non-sterile water for medical procedures that require higher cautionary measures.
  • Exposure of implanted devices to water (e.g. bathing with a central venous catheter improperly covered).

Health and economic implications

Hospital water systems that do not meet regulations can have serious consequences for patients, as well as economic consequences for hospitals, including water contamination, and flooding. Although water issues apply to all homes and businesses, any problems with the water system can be particularly concerning for healthcare premises, as these house patients who are more susceptible to infection, including the elderly, young children, cancer patients, pregnant women, and people with chronic illness.

In March this year, microorganisms were found in the water supplied to Glasgow Royal Hospital for Children and the neighbouring Queen Elizabeth University Hospital. Four children were treated for infections which may have been linked to bacteria in the water supply, with health officials stating that the bacteria could pose harm to patients with ‘compromised’ immunity. Alternatives to tap water supplies were brought in for paediatric patients in selected wards and the hospital’s intensive care unit, with the health board distributing oral antibiotics due to the low immune system of patients on these wards. Sterilised water was also supplied for drinking, as well as bottled water for brushing teeth.

Source still hidden

The then Scottish Health Secretary, Shona Robison, apologised to the patients and families affected, but the source of the bacteria has still not been revealed, with tests ongoing to fully confirm if the infections that the four children had were linked to the water contamination issue. This provides a reminder about the importance of designing, maintaining, and operating safe water systems.

Preventing problems

Prevention is always better than cure –

it’s important to identify areas where those responsible for water systems in healthcare premises can act to prevent contamination of the water system and effectively protect patients, visitors, and employees. Top priorities for healthcare estates teams should include:

  • Placing a strong emphasis on good design.
  • Notifying plumbing work to your water company.
  • Using qualified plumbers.
  • Only using compliant products.

Start with good design

Many old hospital water systems may have been designed piece-meal as areas of the hospital expand or change their use, with poor consideration of how the water system operates as a whole, or putting in appropriate backflow prevention arrangements to prevent contamination.

Any hospital or other healthcare site should thus focus on correctly designing and maintaining its water system, whether building new premises, or making alternations to the existing plumbing system. Designs should consider:

  • The Water Fittings Regulations.
  • Relevant standards, such as BS EN 806, Specifications for installations inside buildings conveying water for human consumption.
  • HTM 04-01: Safe water in healthcare premises.
  • The HSE  Approved  code  of  practice and guidance L8 – Legionnaires’ disease. The control of legionella bacteria in water systems.

The Water Fittings Regulations include common sense design and installation requirements that can prevent issues arising; for example:

Continuous   movement   of   water

The system should be correctly sized for the expected use, so that water does not have the opportunity to stagnate. Any deadlegs should be removed, as any pockets of stagnant water can pose a biofilm risk. Cisterns should be designed for the appropriate capacity, and installed so that there is a good turnover within the whole cistern. This may be particularly important if a series of storage cisterns is used.

Appropriate backflow protection

One very important aspect is that the water system must include suitable devices to prevent backflow, where water may be in contact with fluids assessed as being a fluid category risk of between 2 and 5. Backflow risk is assessed using a system of fluid categories (FC) – where FC1 represents drinking quality water, and FC5 a serious health risk. For example, in private domestic dwellings, dishwashers/ washing machines are rated as FC3. A higher risk from the same appliances used in commercial premises, however, means that the backflow risk there is rated as FC4, or if healthcare is provided in the premises, as FC5.

Inappropriate protection

Heating systems are often found with inappropriate backflow protection. The categorisation of non-domestic primary circuits or heating systems is given in guidance as fluid category 4. This is often due to the presence of chemical inhibitors, which need to be kept out of wholesome water supplies. Water suppliers do, however, adopt a risk-based approach to enforcement, and where a risk assessment indicates that the risk associated with a primary circuit or heating system is lower than a fluid category 4 risk, they will accept alternative approaches.

There are many fluid category 5 risks that may be found within healthcare premises. These include sluices, WC pans, urinals and bidets, baths, birthing pools, grey and rainwater harvesting systems, and hose union taps in bin storage areas. The regulations require use of one of the recognised backflow prevention devices, also rated by fluid categories. The device used must give protection that is at least as stringent as the assessed risk. For example, an appliance with a FC5 backflow risk must have a backflow prevention device or arrangement of fittings which is rated at least FC5. These include a point-of-use tap gap or air gap, or being fed from storage with an appropriate air gap arrangement.

Water temperature

Defra guidance recommends that hot water should be stored at a temperature of not less than 60˚C, and distributed at a temperature of not less than 55˚C. Where practicable, it should also reach the tap and be at least 50˚C within 30 seconds after fully opening the tap. Cold water pipes should not be warmed above 25˚C and ideally not above 20˚C, ‘so far as is reasonably practicable’. Legionella are dormant below 20˚C, but thrive best between 20˚C and 45˚C, with fastest growth occurring at body temperature, 37˚C. Thermal disinfection is one of the most effective recommended controls, with inactivation of Legionella starting at temperatures from 50˚C, and is particularly effective above 60˚C, with significant reductions within minutes above these temperatures.

Compliant products

Choose products and materials that have been properly tested and are suitable for the intended use. Plumbing products and materials which don’t conform to the Water Fittings Regulations or Scottish Byelaws may contaminate drinking water, posing a risk to health.

Notify plumbing work to your water company

Any hospital planning plumbing work may need to get permission from its local water supplier before it starts. This is to make sure that plumbing systems meet UK standards designed to keep our drinking water safe.  Notifications are required by law, and cover a wide range of work  on commercial properties, including building new system, changing the use of a building, and even installing a washing machine. Notifications are not just the law, but they can help hospitals prevent poor plumbing installations, and avoid both the unnecessary costs of putting contraventions right, and enforcement action. Where notified, water companies have the opportunity to identify contraventions, which can  be designed out before work starts.

To gain permission, the water supplier will need the applicant’s name, address, and contact details, a description of the proposed work and location, and details of the plumbing contractor if an approved plumber is being used. Some water suppliers may ask for additional information, such as a list of water fittings and evidence of their compliance with the Water Supply  (Water  Fittings) Regulations or Byelaws.

Supplier’s permission

The hospital can start work when it has received permission from the water supplier. A response is normally given with 10 working days. If a response isn’t received within this time, the hospital can assume that it has consent, and start  work. However, the plumbing work must still comply with the regulations. Notifying the local water supplier is free, and the process is quick, but failure to do so could result in prosecution, or the need to carry out costly work at a later date.

Unfortunately, despite the provision of these comprehensive regulations and extensive guidance, some  hospitals are still failing to protect public health adequately.

Use qualified plumbers

Healthcare premises should always ensure that they are using approved plumbers to carry out any plumbing work, and that there is no risk from poor installation or sub-standard materials that might contaminate the water supply.

WaterSafe-approved plumbers are certified by a national accreditation body, supported by all the UK water companies and drinking water regulators, and are fully qualified to carry out plumbing work in homes and business premises. They have specific training in the Water Fittings Regulations, which enables them to ensure that there should be no risk from poor installation or sub-standard materials that could cause contamination of the drinking water supply.

A ‘certificate of compliance’ issued by a WaterSafe-approved plumbing business provides a defence for property owners who are challenged by a water supplier enforcing the Water Fittings Regulations and Byelaws. WaterSafe-approved plumbing businesses must also adhere to the WaterSafe code of conduct and customer commitments; where they fail to meet these standards, a disciplinary process applies. Furthermore, a WaterSafe-approved plumbing business which fails to uphold the standards will be subject to a range of penalties; in serious cases, this would result in its membership of WaterSafe being revoked.

Requirement to put work right

A WaterSafe-approved plumbing business will be required to put its work right if it does not meet the requirements of the Water Fittings Regulations or Byelaws, enforced by the water supplier. For most types of plumbing work, the person commissioning the work has a legal duty to ensure that the water supply company is notified before it starts work. This is an important step in making sure that systems are compliant, and needs to be factored in to prevent delays. However, a WaterSafe-approved plumber can carry out some work without the need to provide this advanced notification to the water company.

Only use compliant products

Plumbing products (water fittings) which don’t conform to the Water Fittings Regulations or Byelaws in Scotland may contaminate drinking water, posing a risk to health. The regulations require water fittings to be of an ‘appropriate quality and standard’ to ensure that their design and manufacture prevents waste and contamination. Plumbing  products are considered suitable if they pass appropriate material and mechanical regulatory performance tests. These tests include checks that products won’t affect the taste or smell of drinking water,and do not promote the growth of microorganisms.

You might think that nobody would sell a plumbing fitting which is illegal to install,but sadly you’d be wrong. Under the regulations it is not illegal to sell such a fitting. However, a seller would be breaking consumer protection law, although the sale of non-compliant fittings appears to be common. This means that checking compliance is really important. So, if you are specifying, purchasing, or installing water fittings, how can you tell if the product complies? One easy way to check if a product is suitable is to look for an approval mark from organisations like the Water Regulations Advisory Scheme (WRAS), Kiwa Watertec, or equivalent schemes. Both provide directories of approved products, at or

Suitable installation

Choosing an approved fitting ensures that you are using one that is designed and manufactured to meet appropriate standards, but how it is installed can also affect whether or not it complies with the regulations. Some approved products, while appropriately designed and constructed, may not meet every installation need. For example, if an appliance has a clear plastic inlet hose, this can allow light into the water path and encourage algal growth, causing poor water quality. So, the product needs to be installed only where the hose can be kept in the dark, such as behind panels or in cupboards. In other products there may need to be additional fittings installed, such as a single or double check valve on the water inlet pipe to ensure correct backflow protection.

To help provide specifiers, designers, and installers with information to help them decide if a product is suitable for the intended use, both WRAS and KIWA approvals schemes provide Installation and Requirement Notes. These installation conditions must be followed to ensure that the product complies once installed.

HTM 04-01 offers further advice about the suitability of materials. For example, it raises concerns with some types of flexible water supply hoses, Materials such as ethylene propylene diene monomer (EPDM) rubber may be susceptible to microbial colonisation.


Hospitals and other healthcare sites contain complex plumbing systems serving vulnerable patients who are more at risk of waterborne pathogens than individuals in excellent health. This presents significant challenges for those responsible for water systems, but properly designed water systems that use approved, tested water fittings, and that are properly installed by a WaterSafe installer, will provide important safeguards against the serious threat of water contamination and other consequences.

  • For more information about complying with the Water Fittings Regulations, please visit the WRAS website, at, or contact your local water company.

Paul Millard

Paul Millard, who has 25 years’ water industry experience, joined WRAS in August 2012, and in his role as Technical manager he provides technical liaison and support both to the water industry and other external organisations. Prior to this he worked for Anglian Water as Water Regulations manager, responsible for the company’s enforcement of Water Fittings Regulations. His early career saw him involved in activities including network management, leakage, and customer complaints.

Over the past 15 years his work has entailed a heavy focus on providing technical expertise and guidance on the enforcement and interpretation of Water Fittings Regulations – leading to his involvement with national standards, where he provides representation for the water industry.


Please enter your comment!
Please enter your name here