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20 February 2019
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Water, by law, has to be wholesome – and part of this comes down to satisfactory taste and odour, says Julie Spinks.

© iStock
© iStock

04 December 2018 | Julie Spinks


The Drinking Water Inspectorate report shows 99.96 per cent of samples in England and Wales passed water quality tests in 2017 but of the 640 samples that failed, about a quarter were due to taste and odour. 

This is often caused by problems with the private pipes and water fittings, and the householder or business will be responsible for fixing them. 

But if a smell or taste remains after remedial work, you should contact your local water company. In most cases, FMs will need to address these common complaints.

1. Antiseptic or metallic taste

Common cause: Chlorine reacting with rubber fittings in appliances.

Solution: Close the isolating valve on the water pipe leading to the tap for 24 hours, then taste and smell the water. If the taste persists, replace plastic parts with approved products. Check outside taps have adequate backflow protection. 

2. Earthy and musty tastes

Common cause: Stagnant water or algae, bacteria or other organic matter in rivers or reservoir.

Solution: If premises are empty for a week or so, water quality can deteriorate, so run taps to flush out any standing water. Make sure hot and cold water taps are insulated and kept separate. Water companies treat water to remove matter, but sometimes harmless fragments remain.

3. Stagnant or sewage smells

Common cause: Blocked waste pipes.

Solution: Pour a glass of water and take it to another room. If the smell disappears, make sure taps are cleaned regularly and no solid waste 

is tipped down plugholes.  

4. Metallic or bitter taste

Common cause: Higher levels of metals in 

internal pipework.

Solution: Run water through the tap. Consider replacing pipework with approved products if the problem persists.

5. Chlorine taste and smell

Common cause: Water companies keep chlorine levels as low as possible, but it’s required to keep water healthy. The concentration of chlorine can vary depending on time of day or season, so if there is an issue with taste and smell, it may be temporary. 

Solution: Reduce the taste and smell of chlorine by filling a jug with water, covering it and leaving in the fridge. If it has not been used after 24 hours, it should be recycled to water plants or for other uses.

Preventing problems

When building new premises or altering existing plumbing systems, changes must comply with:

  • Water fittings regulations; and
  • Relevant standards such as BS EN 806 – ‘Specifications for installations inside buildings conveying water for human consumption’.


Common sense design and installation requirements can prevent issues arising.

  • Continuous movement of water: The system should be correctly sized for the expected use, so water does not stagnate. Any ‘dead-legs’ should be removed, as a pocket of stagnant water can pose a biofilm risk. Cisterns should be designed for the appropriate capacity and installed so there is a good turnover in the whole cistern. 
  • Appropriate backflow protection: 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 to 5.
  • Backflow risk is assessed using a system of fluid categories (FC) – where FC1 represents drinking quality water and FC5 represents a serious health risk.  
  • Use compliant products and materials: If they don’t conform to the water fittings regulations or Scottish bylaws, they may leak  or contaminate drinking water.



Plumbing work may require permission from the local water supplier. It will need the applicant’s contact details, and a description and details of the contractor if an approved plumber is being used. Failure to notify could result in prosecution. 

Use an approved plumber

Use a member of WaterSafe, the UK register for approved plumbers. The scheme is backed by all UK water companies and drinking water inspectorates. Members are trained in regulations, carry public liability insurance and are subject to a complaints process if there are concerns about the standard of work.  

Julie Spinks is director of Watersafe